5281 5285.output

* GB785688 (A)

Description: GB785688 (A) ? 1957-11-06

Fuel feed and power control system for gas turbine engines

Description of GB785688 (A)

PATENT SPECIFICATION Date of Application and filing Complete Specification: May 6, 1954. 785,688 No 13258/54. t t t 20 Application made in United States of America on May 27, 1953. Complete Specification Published: Nov 6, 1957. Index at acceptance:-Classes 110 ( 3), C 1 OE( 11 83:113 X:2 X); and 135, P( 1 C:1 X:9 X:11: 16 C:16 E 1:18:24 KX). International Classification:-FO 2 c. COMPLETE SPECIFICATION Fuel Feed and Power Control System for Gas Turbine Engines We, BE Ni Dx Av IATION CORPORATION, Oe 401 North Bendix Drive, South Bend, Indiana, United States of America, a Corporation organized uander the Laws of the State of Delaware, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:The present invention relates to a fuel control system and more particularly to a fuel control system and a method of operation for gas turbine engines. In acceleration of gas turbine engines, particularly those embodying an axial flow compressor, a phenomenon known as compressor stall or surge may be encountered in which the back pressure of the compressor exceeds some critical value, usually resulting in a sudden and drastic reduction in the quantity of air delivered to the burners If this condition is not immediately relieved by reducing the fuel delivery to the engine, the burner temperatures and the vibratory stresses induced in the compressor may become sufficiently high to cause serious damage to the engine. Most of the fuel controls now in use on gas turbine engines include a mechanism which schedules the fuel flow duringf acceleration such that

the compressor stall region for the particular engine is avoided. In determining the schedule, however, a substantial safety margin must be provided which necessarily decreases the rate at which the engine can be accelerated, particularly since the compressor surge region varies with variations in engine operating conditions It is therefore one of the principal objects of the present invention to provide a fuel control system for gas turbine engines which will permit maximum acceleration throughout the lPrice 3161 entire operating range of the engine. Another object of the invention is to provide a fuel control device for gas turbine engines which will anticipate the approach of the compressor stall condition 50 and respond instantaneously to prevent the engine from reaching that condition. A further object of the invention is to produce a signal which indicates the condition uender which a gas turbine engine 55 is operating during various stages of acceleration. A further object is to provide a mechanism which is capable of sensing variations in the aforesaid signal and 60 responding promptly thereto to deliver the required fuel flow to the engine. A still further object of the invention is to provide a method of sensing the approach of compressor stall 65 Additional objects and advantages of the invention will become apparent from the following description with reference to the accompanying drawings, wherein: Fig 1 is a block diagram showing part 70 of a gas turbine engine and various components of a device or system embodying the invention; Fig 2 is a schematic diagram showing one embodiment of the fuel control device; 75 Fig 3 is a schematic diagram of another embodiment of the fuel control device; Figs 4 and 5 are curves showing the effect of fuel flow modulation on compressor outlet pressure under various 80 operating conditions; and Fig 6 is a curve showing fuel flow plotted against engine turbine speed. The present invention involves a fuel control mechanism and method of opera-85 tion in which a predetermined fuel flow oscillation is superimposed on the fuel delivered to the engine to produce pulsations in an engine operating condition such as the compressor discharge pressure 90 785,688 The pulsations in the compressor discharge pressure or other engine operating condition are the direct result of variations in burner temperatures and correspond uniformly in amplitude and frequency to the fuel flow modulation except deuring acceleration of the engine As the engine accelerates, the amplitude of the pulsations in the compressor discharge pressure or other engine operating condition gradually diminishes as the engine approaches the compressor stall stage, reaching almost zero as this stage is entered The present invention utilizes the variations in the pulsations in the

compressor discharge pressure or other engine operating condition to control the engine fuel system to obtain maximum acceleration without danger of compressor stall. Referring more specifically to the drawing S and to Fig 1 in particular, numeral designates a oas turbine engine having an axial flow compressor 12, burners 14, turbine 16 and fuel discharge nozzles i S disposed in burner 14 Fuel for the engine is delivered from a tank or the like (not shown) through conduit 20, and pump 22 to a primary fuel control unit 24, of any well-known type, controlled by the pilot. On leaving the control unit 24, the fuel passes through conduit 26, regulating valve unit 28, and conduit 30, to a modulator or pulsator 32 and from there through conduit 34 to nozzles 18 and is discharged into burners 14 The pulsations created in the fuel flow to the burners by modulator 32 produce a corresponding variation in the temperature in the burners and consequently in the back pressure at the discharge end of compressor 12 during the time the engine is operating in a steady state condition The pulsations thus created in the compressor discharge pressure are piecked up by conduit 40 and transmitted through conduit ' to a sensor unit 42 where they are converted into an electrical signal -which is compared with a reference voltage and amplified for use in operating regulating valve 28 to prevent compressor stall when variations in amplitude of compressor discharge pressure pulsations indicate the approach of the stall condition. The modulator 32 consists of a housing 30, Fig 2, having a fuel inlet 52, a fuel outlet 54 connected by a chamber 56 having disposed therein a rotor 58, which is shown as a shaft like member having a bevelled end for varying the size of the outlet 54 within a limited range with each revolution of the rotor to eause a pulsating flow in conduit 34 to nozzles 18 The rotor 38 in the embodiment of Fig 2 is driven at a constant speed by a hydraulic motor 60 connected by a conduit 62 to conduit ' between pump 22 and the prirnary control 24 and to conduit 26 on the downstream side of the primary control 24 by a conduit 64 In order to maintain the speed of the hydraulic motor constant a 70 constant head regulator 66 is connected across the motor and contains a chamber 72 connected to conduit 62 by conduit 68 for motor inlet pressure and a chamber 74 connected to conduit 64 by conduit 7075 for motor outlet pressure, said latter conduit being connected to chamber 72 1 by a conduit 76 to form the outlet for said chamber The fuel outlet of chamber 72 is controlled by a valve 78 regulated by a 80 flexible diaphragm 50 urged in the valhe closing direction by a coil springe' 82 which determines the drop in pressure from the inlet to the outlet of the motor. The pulsations created in the eompressor 85 outlet pressure by the pulsating fuel lo-v are transmitted through conduits 40 and ' to

sensor unit 42 which contains two resonating chambers 90 and 92 separated by) a diaphragm 94 and connected to oii',90 another by a conduit 96 controlled by a valve like member 98 for tuning the sensor to the pulsations of the compressor discharge pressure The vibrations of the diaphragm actuate an armature 100 of a 95 coil 102 and are thereby converted into an electrical signal of a frequency and amplitude corresponding to the pulsations of the compressor discharge pressure This electrical signal is fed through an amplifier 100 and rectifier 103 into a mixer 104 where it is compared to a reference voltage and the resultino error signal is then amplified by amplifiers 103 and 106 Any suitable rectifiers, mixers and amplifiers, such as 105 those disclosed in our copending Patent Application No 7479/54 (Serial No. 785,687) may be employed in the electrical system An electrical voltage corresponding to the error signal operates a torque 11 o motor 108 to control regulator valve 28 to decrease the fuel flow to the engine if the compressor outlet pressure pulsation indicates that the engine is approaching the compressor stall region 115 The regulator valve unit 28 consists of a balanced valve 110 controlled by a piston 112 in cylinder 114 The operation of piston 112 is controlled by motor 108 through valve 116 which is connected to 120 each side of said piston by conduits 118 and 120 and to conduit 26, as a source of operating pressure, by conduit 122 A conduit 124 and branch conduits 124 ' and 12 are provided to relieve the pressure 12 s on either side of the piston as the valve 11 l 6 is moved to regulate valve 110 in controlling the piston The movable member of valve 116 forms three shiftable chambers 126, 128 and 130, chamber 128 being 130 785,688 adapted to connect conduit 122 with con(Init 118 to move piston 112 in the direction to close valve 110 and with conduit to move the piston in the direction to open the valve. A constant pressure drop is maintained across the regulating valve by a pressure regulator unit 134 consisting of a fuel inlet chamber 136 and a fuel outlet chamber 138 separated by a partition 140 having an orifice therethrough controlled by a valve 142 The inlet chamber is connected by conduits 146 and 64 to conduit 26 upstream of regulating valve unit 28 and contains a bellows 148 connected by conduit 150 to conduit 30 downstream of said unit The outlet chamber is connected by conduit 152 to conduit 20 anterior to pump 22 and contains a bellows 134 connected by conduits 156 and 64 to conduit 26 The two bellows operate valve 142 which is urged toward closed position by a spring 158 disposed in bellows 148. To prevent the regulating valve from travelling farther than required to properly control the engine, an anticipator which includes an electrical coil 159 having an armature actuated by the movement of

piston 112, senses the rate of travel of piston 112 and modifies said rate as the desired position of the valve is being approached and thus prevents overshooting and hunting of the valve 110. A unit 160 is included to override the normal fuel control mechanisms in the event unit 42 fails and the engine actually reaches the compressor stall stage This contains two resonating chambers 164 and 166 separated by a diaphragm 168 and connected to one another by a conduit 170 controlled by a valve like member 172 for tuning the vibrations of the diaphragm to the engine acoustic resonance frequency, which is always encountered when the engine is operating in the compressor stall region The vibrations of the diaphragm actuate an armature 174 of coil 176 and are there converted into an electrical signal of a frequency and amplitude copresponding to the engine resonance pulsation The electrical signal is fed through an amplifier and rectifier 178 into a mixer 180 in the previously mentioned circuitry and, if the signal indicates that the compressor stall stage has been reached, causes regulator valve 28 to move toward closed position to prevent damage to the engine. In the operation of the present control mechanism, when the engine is operating at steady state, for example during idling, fuel flow modulator 32 creates continuous pulsations of small amplitude in the fuel flow to the engine burners This pulsating fuel flow causes a corresponding variation in burner temperatures which in turn causes a like variation in back pressure at the compressor outlet; hence during steady state operating conditions the compressor discharge pressure pulsations follow uni 70 formly the fuel flow pulsations The pulsations of the compressor discharge pressure are transmitted to the sensor unit 42 where they are converted into an electrical signal by armature 100 and coil 75 102 This signal is compared with a reference voltage in mixer 104 and at steady state the error voltage which appears at the torque motor urges valve to its fully open position In Fig 480 the curve showing the pulsations of the fuel flow produced by modulator 32 in the fuel metered by the primary control 24 and the curve showing those of the signal produced by pulsations in the pressure dis 85 charge pressure (P 2) show that the modulation of these two are characteristically the same, in this example, consisting of a relatively low amplitude sinusoidal oscillation 90 When the pilot desires to accelerate the engine, the primary control 24 is regulated to increase the fuel flow The modulator 32 continues to produce the pulsating flow throughout the acceleration 95 range As shown in Fig 5 the fuel flow pulsations remain constant in frequency and amplitude throughout this range; however, some predetermined varying amplitude may be used The pulsations 100 in compressor discharge remain constant in frequency until compressor stall stage is reached but decrease in

amplitude to almost zero from the beginning of acceleration range to the compressor stall stage 105 and increase in amplitude from the stall stage to steady state It is the diminishing pulsation amplitude which, after being converted to an electrical signal by sensor unit 42, is compared with the reference ll O voltage, amplified and converted into an electrical voltage for operating torque motor 108 to decrease the fuel flow through valve unit 28 in the event the operation of the engine approaches closely to the com 115 pressor stall region The engine accelerates, as shown in Fig 6 where fuel flow (Wf) is plotted against engine speed (N),, from point A on the steady state curve along the broken line to point,EB where it 120 approaches the compressor stall region, skirts this region until the desired speed is reached at point C and then drops to point D on the steady state curve By sensing the change in compressor outlet pressure 125 pulsations and using this as a signal to detect the approach of compressor stall, it is seen that the engine can be safely accelerated near the permissible maximum compressor stall limit, thus reducing to a 130 785,688 minimum the time required for aecelera tionl. In the modification of the present inven tion showvn in Fig 3, wherein element found in the preceding figures are givei lile numbers, the electrical seinsing anc amplifying mechanisms have been replace( ly a hvdro-meehanical inechanism and tho mechanical modulator 32 has been replacec by an electrically actuated unit In tlih latter unit a valve assembly 200 contains a valve element 202 operated by a solenoid 204 to move it between predetermrined limits less than fully opened or closed, the operation of the solenoid bein g controlled by an oscillator 205 The pulsations ereated in the fuel line to the burners bv the modulator unit are the same in character as those produced by unit 32. The pulsations in the compressor discharge pressures are transmitted to sensor mlit 42 -where they cause diaphragm 94 to vibrate anid operate stem 210 to reciprocate valve 212 of valve unit 214 The latter unit is connected with conduit 26 on the upstream side of -valve unit 28 by conduits 216 and 216 ' and with conduit 30 on the downstream side of unit 28 by conduits 218 and 220 Valve 212 controls the flowr of fuel from conduit 216 ' to branch conduits 220 ' and 220 " of conduit 220 and consequently the pressure in actuator 222 This actuator contains a chamber 224 connected to conduit 220 anterior to a restriction 226 and another chamber 228 connected to conduit 220 posterior to restriction 226 and separated from the first chamber by diaphragm 230 which together with a spring 231 actuates valve member 116 through a linkage consisting of rod 232, lever 234 and stem 236 Lever 234 is pivoted on a support 237 which is made adjustable to permit the position of the lever to be shifted to make minor

adjustments in the position of valve member 116. In this arrangement, as diaphragm 94is vibrating uniformly during steady state operation of the engine, valve 212 opens and closes branch conduits 220 ' and 220 ", creating uniformly pulsating pressure in conduit 220 above restriction 226 and in chamber 224, and a substantially constant pressure drop between chambers 224 and 228 During this time the fiection of diaphragm 230 is sufficient to hold valve 116 in the position to connect conduits 120 an 1 d 122 and thereby retain regulating v-alve 110 in its fully opened position As the pulsations in compressor discharge p 'essure decrease during acceleration, a corresponding decrease occurs in the magnitude of the vibrations of diaphragm 94 which causes a decrease in the movement of valve 212 This results in a lowering of the pressure in conduit 220 above restriction " 6 and eonjseciuenitly a lesser pressure drop across said restriction and likewvise aeross diaphra-m 230 The s diaphlram sprimi) 2 ' 11 operatingi tlhrouhrli j rod 232 lever ',j a n'd stem 2:36 moves 70 dvalve 116 upiwardly to conlect Cou 1 duit ll S 1 with conduit 1 '2 thlougi chamber 128 and 3 thereby move piston 112 in the direction to 1 close valve 110, thns a' iding ompressor e stall 75 Unit 160 is also ineluded in this system and operates a valve unit 238 to produce 1 a pressure difterenitial in am actuator 240. This actuator contains a chamber 242 connected to conduit 244 above a restriction 80 243 and another chamlber 246 coniected to c conduit 244 be Low saif restriction A diaphragni 24 separates chamiber 242 and 246 and is connected to a rod 2730 which has an adjustable abutment 232 for 85 engaginlg the free end of lever 234 Rod 250 is moved in the direction to disen-age the abutment froom lever 234 by a eoil spring 2354 in chamlber 246 The valve unit 238 is connected with conduit 216 bygo conduit 2 '6 and with conduit 21 S bl conduit 244 and branch conduits 244 ' and 244 " and operates in the same manner as unit 214 in response to the vibration of diaphragam 168 of unit 160 Unit 160 is 95 tuned to the acoustic resonance of the engine and, if the engine enters the stall stage should unit 42 fail the resulting, acoustic resonance actuates sensor 160 such that the diaphragm begins to vibrate and 100 operates valve 2238 in the manner previously explained with reference to valve 21 ', thus producing, a substantial pressure differential across diaphragm 248, moves rod 250 in the direction to cause 105 valve 28 to move toward closed position. The fuel flow is decreased sufficiently to return the engine to normal operatin r conditions.

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* GB785689 (A)

Description: GB785689 (A) ? 1957-11-06

Method of making a pressure filled lamp


PATENT SPECIFICATION Date of Application and filing Complete Specification: Feb 7, 1955. 785,689 No 3615155. / i Application made in United States of America on Feb10, 1954. Complete Specification Published: Nov, 6, 1957. Index at acceptance:-Classes 9 ( 2), L; and 39 ( 2), B 2 (B:E). International Classification:-CO 6 d, H Olk. COMPLETE SPECIFICATION Method of Making a Pressure Filled Lamp We, SYLVANIA ELECTRIC PRODUCTS INC, a corporation organized under the laws of the State of Massachusetts, United States of America, of 60, Boston Street, Salem, Massachusetts, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to a method of making a pressure filled lamp and a lamp when made by the method More particularly, but not exclusively, it relates to a method of making a photoflash lamp and a photoflash lamp when made by the method. There has been a great deal of effort expended in recent years to design and develop a photoflash lamp which is considerably smaller in size, more economical to produce and not provided with the normal bayonet or screw type socket of the lamps of prior art Although the lamps of the prior art have been greatly reduced in size throughout the years their basic configuration has remained substantially the same, due primarily, to the manufacturing problems which were

encountered when trying to change the basic design of the lamp. While it has been recognised that some of these objectives could be realized by increasing the gas pressure within the lamp the problem of sealing such a lamp has not been solved heretofore. The real problem has been in making a good pressure seal in an oxidizing or even neutral atmosphere The sealing techniques heretofore suggested have not been practicable for this purpose and as a result photoflash lamps which are actually offered for sale have been kept at less than atmospheric pressure. It is an object of the present invention to provide a new method of making a pressure filled lamp. lPrice 3/61 According to the present invention there is provided a method of making a pressure filled lamp including fitting a metallic cap over an open end of a lamp envelope, introducing the assembled components into a 50 chamber where atmosphere can be controlled and in which the tube envelope is surrounded by a metallic hood shielding the tube envelope and its contents against the application thereto of high frequency energy, and 55 heating the metallic cap by high frequency energy to form a gas-impervious seal between the metallic cap and tube envelope. A method in accordance with the present invention of making a photoflash lamp will 60 now be described, by way of example, with reference to the accompanying drawing wherein:Fig 1 is an enlarged view of a front elevation of the photoflash lamp; 65 Fig 2 is a front elevation partly in section of a device suitable for use in manufactur ing the photoflash lamp illustrated in Fig 1. The flash lamp illustrated in Fig 1 of the drawing has a tubular glass envelope 10 70 which is reduced in diameter at the end which is sealed into the base portion of the flash lamp, as shown in the drawing the reduced diameter being accurately determined This tubular envelope 10 is sealed 75 to a metallic base cap 14 whose side walls extend upwardly a sufficient distance to embrace the reduced area 12 of the glass envelope 10 The base of the cap is provided with a circularly depressed segment as shown 80 at 16 which provides adequate space for the seating of a contact button 18 which is sealed therein by an air impervious seal which also electrically insulates the button 18 from the base cap 14 The method illustrated in the 85 drawing is one in which the glass frit 20 has been used to form a glass-to-metal seal between the button 18 and the seat at 16 provided in the base cap 14. The base cap 14 illustrated is provided 90 785,689 with a centrally located opening at 22, this opening being sufficiently large to permit the passage of a wire lead 24 therethrough and being usually at least four times the diameter of the wire lead This wire lead 24 is in good electrical contact with the contact button 18, but is insulated from

the base cap 14 by means of the fused glass frit 20 in the same manner as is the button 18 A second wire lead 26 is maintained in good electrical contact with the inside of the base cap 14 Each of these two lead members 24 and 26 is provided near its free end with a blob 28 of ignition paste A thin filament 30 also connects the two lead wires 24 and 26 at these points The inside of the envelope 10 is further provided with a material such as shredded foil 29 which is capable of serving as a source of actinic light when the lamp is flashed The envelope 10 is, of course, sealed to the cap, 14 by suitable means, the material 31 shown in Fig 1 being a glass enamel produced from a glass frit. The envelope which is used in the making of the lamps may of course, be made of any gas impervious material which is sufficiently transparent to permit the transmission of light which is produced therein It should, of course, be of such characteristics that will enable it to be used without fear of flying fragments resulting from the burning of the materials within the lamp at the time the light is being produced therein For this reason when glass is used as the enclosing envelope it has been found advisable to coat the outside of the glass with a clear lacquer, indicated by 32, which will at least serve to bind the fragments, even though the envelope itself cracks due to the heat and pressure developed during the rapid burning of the materials producing the light. The tubular shape which is made use of in accordance with this invention makes it possible to provide a greater volume of the necessary oxygen within the lamp than would be possible if a lamp having similar outside proportions were used, but were further provided with a restricted portion such as is usually customary with the flash lamps of the prior art which are provided with a restricted neck fitting into the socket It has been found that lamps which have the design above shown can further be manufactured with the gas pressures within the lamp greater than those normally used in the lamps of the prior art For the most part the lamps of the prior art usually contain oxygen at a bit more than 2/3 of an atmosphere Lamps of the design shown herein can readily be made with internal pressures ranging up to 2 atmospheres while still maintaining the necessary safety factor The lamp as shown in Fig 1 is substantially enlarged A more accurate sized lamp is shown in Fig 2 of the drawing which illustrates the manner of fabricating these lamps, this lamp having an overall length of about 13 ins. ( 45 mm) and a diameter of about 21132 ins. ( 17 mm). The metal material for the base cap 1470 can be chosen from a wide variety of materials When a direct seal is made between the envelope

10 and the base cap 14 it is, of course preferable to mialke use a a material which will lend itself to this pur 75 pose, such as a recognized glass-to-metal sealing alloy Many materials are known to the prior art The material can be so chosen as to have a co-efficient of contraction greater than the bulb or in the manufac 80 ture of the lamp a differential cooling schedule can be effected, so that from a temperature representing the set point of the enamel to the room temperature the material has an effective higher co-efficient of contrac 85 tion than the bulb This will result in a radial compression type of seal of cap flange around the bulb Examples of metals which are suitable for use for this purpose are as follows: 38 to 453, nickel 3 to 15 <, chro 90 mium, 0 1 to 2 < aluminium, zirconium or calcium, and the rest iron, all percentages being by weight When glass frit is used in making the seal cold rolled steel can be used 95 There are, of course, a number of techniques which may be used to make lamps which structurally resemble the flash lamp shown in Fig 1 of the drawing A preferred method of doing this is to first weld the elec 100 trade 26 to the inside of the base cap 14 and then, in those cases in which cold rolled steel is used rather than a glass-to-metal sealing alloy, to coat the inside surface particularly the inside wall surface with a glass 105 frit The outside of the depression 16 in the end of the base cap 14 should also be so coated whereupon the button 18 to which the wire lead 24 has previously been centrally attached is placed within the seat and 110 the assembly placed within a furnace In the furnace the temperature of the assembly can be raised to the fusion point of the glass frit so as to form a glass enamel layer over the inner end surface of the base cap (or, 115 if preferred, over the entire inner surface of the cap), a glass seal between the button 18 and the bottom of the base cap 14 and a glass seal at the point at which the wire lead 24 passes through the centrally positioned 120 opening in the cap This cap assembly is then ready for the welding of a filament 30 across the leads 24 and 26 and the application of the ignition paste 28, which usually has a zirconium powder base 125 After the material which is to provide the source of actinic light such as shredded foil 29 has been filled into the envelope 10, the cap assembly which has been prepared in accordance with the previously described 130 785,689 method can be mounted on a metallic rod such as is shown at 40 in Fig 2 of the drawing The envelope containing the shredded foil can then be loosely seated within the tubular side wall of the base cap 14 whereupon a hood-like member 42 is placed over the glass tubular area This hood-like member 42, as shown in Fig 2 of the drawing, is provided with a spring 44 extending upwardly from its top surface This spring is made sufficiently long to enable it to engage the top of a bell jar-like member 50 which is then placed on top of

the spring and pressed downwardly so as to hold the tubular member 10 firmly against the supported cap 14 When in this position the bell jarlike member 50 is seated on a resilient ring 52 and is pulled downwardly thereon toward an annular seat 54 by means of a screwthreaded member 56 provided with an inwardly projecting flange 58 which engages an outwardly projecting flange 60 of the bell jar-like member 50. When the device has been assembled as indicated above the lamp is located in an hermetically sealed chamber which is connected to the outside through a series of holes 62 provided in the bottom end of the rod 40, which is tubular at this point, and a bore in a tubular member 64 which passes through the member 54 but is hermetically sealed thereto This tubular member 64, as shown in the drawing, leads to a crossshaped member 71, one leg 72 of which is connected to a vacuum pump, another 74 to a source of oxygen gas, a third leg 76 to a gauge and the fourth to the tube 64 The legs 72 and 74 are connected to the pump and source respectively through valves (not shown) which can be so regulated as to cause all the air to be withdrawn from within the chamber after which oxygen gas at any desired pressure can be introduced therein. The pressure which has to date been found to be particularly suitable is one in the neighbourhood of 1 6 atmospheres When this oxygen pressure has been reached a radio frequency coil 70, which is shown surrounding the bell jar-like member 50 at a point close to the base cap 40, is activated When this is done the annular layer of glass enamel on the inner side wall of the base cap is caused to soften, wetting the envelope 10, after which the lamp is permitted to cool If this is done under the proper time temperature conditions a good glass-enamel-metal seal is formed between the envelope and the cap and the flash lamp can be withdrawn from within the member 50 and is now ready for use. In practicing this sealing technique using radio frequency energy applied to the side wall of the base cap it is, however, extremely necessary to provide some means for holding the heat to a desired area of the cap Otherwise, there would be a tendency for the glass seal which has been formed between the button 18 and the base cap 14 to crack, or at the very least become gas pervious Furthermore, means must be provided to hold the 70 heat as close as possible to the bottom of the cap and the part of the envelope to which the cap is being sealed, and away from the remainder of the envelope, for two purposes Firstly the appearance of the 75 glass tubular envelope may be spoiled if the heat were to be allowed to cause the envelope to be deformed and secondly to keep. the heat away from the ignition paste for fear of producing

pre-ignition and therefore 80 a worthless lamp The rod 40 as shown in Fig 2 of the drawing has been provided to act as a means for withdrawing heat from the base cap at a sufficiently rapid rate to prevent the melting of the part of the glass 85 enamel layer immediately adjacent the button 18 To accomplish this a good heat conducting material is chosen with a sufficiently massive structure to permit adequate heat conduction from this critical area The mem 90 ber 42 besides serving to hold the tube firmly pressed against the cap member also serves as a heat shield This member is preferably caused to extend downwardly to a point which is slightly below the top level of the 95 base cap, thus helping to isolate the direct radio frequency energy which is absorbed by the base cap 14, so that the heat is directed to the part of the lamp where it will do the most good in melting the glass enamel and 100 causing a direct glass-to-metal seal at the desired points In a way it also serves as a heat shield and instrument for dissipating heat from undesired areas. The projecting edge of the cap 14 not 105 only adds strength to the structure and thereby permits the use of relatively thin metal stock, but also serves as a means to help localize the heat during the sealing operation Since the edge projects a slight dis 110 tance further out from the center than does any other part of the lamp it is closest to the coil 70 and therefore serves as the locus for the radio frequency energy. Projection lamps which use a neutral 115 atmosphere can also be made in accordance with the fundamental principles of the method herein described The characteristics of such lamps are also improved by such increase in pressure since it assists in dissip 120 ating the heat given off during operation and also tends to decrease the vapour pressure of the tungsten filament Both of these factors, of course, beneficially affect the life characteristics of the lamp 125 While the above description and drawings submitted herewith disclose a preferred and practical embodiment of the photoflash lamp of this invention it will be understood that the specific details of construction and 130 785,689 arrangement of parts as shown and described are by way of illustration and are not to be construed as limiting the scope of the invention. There is disclosed and claimed in our copending application No 3617155 (Patent No. 785,690) a projection or photoflash lamp comprising a tubular light-pervious member with an end thereof which is sealed into a cup-shaped metal base member and is embraced by the side wall of the base member, the part of the tubular member embraced by the side wall being reduced in diameter to an extent such that the exterior surface of the base member side wall is flush with the exterior surface of the

tubular member.

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* GB785690 (A)

Description: GB785690 (A) ? 1957-11-06

Improvements in or relating to projection or photoflash lamps


PATENT SPECIFICATION 785,690 Date of Application and filing Complete Specification: Feb 7, 1955. Application made in United States of America on Feb 10, 1954. Complete Specification Published: Nov 6, 1957. index at aeceptanoe -Classes 9 ( 2), L, and 39 ( 2), B 20. Intemnational Hkass fication:-C 06 ci Hlk. COMPLETE SPECIFICATION Improvements in or relating to Projection or Photoflash Lamps We, SYLVANIA ELECTRIC PRODUCTS INC, a corporation organized under the laws of the State of Massachusetts, United States of America, of 60, Boston Street, Salem, Massachusetts, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention is concerned with improvements in or relating to projection and photoflash lamps. There has been a great deal of effort expended in recent years to design and develop projection and photoflash lamps which are considerably smaller in size, more economical to produce and not provided with the normal bayonet or screw type socket of the lamps of

the prior art Although the lamps of the prior art have been greatly reduced in size throughout the years their basic configuration has remained substantially the same, due primarily, to the manufacturing problems which were encountered when trying to change the basic design of the lamp. It is an object of this invention to provide a projection or flash lamp having a radically different structural design than the lamps of the prior art but yet amenable to processing techniques which will permit the lamps to be made on a commerciallypracticable basis. According to the present invention there is provided a projection or photoflash lamp comprising a tubular light-pervious member with an end thereof which is sealed into a cup-shaped metal base member and is embraced by the side wall of the base member, the part of the tubular member embraced by the side wall being reduced in diameter to an extent such that the exterior surface of the base member side wall is flush with the exterior surface of the tubular member. In the drawing which illustrates an emlPrice 316 l bodiment of this invention Fig l is an enlarged view of a front elevation of a photoflash lamp of this invention;. Fig 2 is a front elevation partly in sec 50 tion of a device suitable for use in manufac turing the photoflash lamp illustrated in Fig 1. The flash lamp illustrated in Fig 1 of the drawing has a tubular glass envelope 10 55 sealed into a cup-shaped metallic base cap 14 whose side wall extends upwardly a sufficient distance to embrace a reduced area 12 of the glass envelope 10 The extent of the reduction in the diameter of the area 12 is 60 accurately determined so that the exterior surface of the base cap side wall is flush with the exterior surface of the tubular envelope 10, as shown in the drawing The base of the cap is provided with a circu 65 larly depressed segment as showii at 16 which provides adequate space for the seating of a contact button 18 which is sealed therein by an air impervious seal which also electrically insulates the button 18 from the 70 base cap 14 The method illustrated in the drawing is one in which glass frit 20 has been used to form a glass-to-metal seal between the button 18 and the seat at 16 provided in the base cap 14 75 The base cap 14 illustrated is provided with a centrally located opening at 22, this opening being sufficiently large to permit the passage of a wire lead 24 therethrough and being usually at least four times the diameter 80 of the wire lead This wire lead 24 is in good electrical contact with the contact button 18, but is insulated from the base cap 14 by means of the fused glass frit 20 in the same manner as is the button 18 A second 85 wire lead 26 is maintained in good electrical contact with the inside of the base cap 14 Each of these two lead members 24 and 26 is provided near its free end with a blob 28 of ignition paste A thin

filament 30 also 90 No 3617/55. 785,690 connects the two lead wires 24 and 26 at these points The inside of the envelope 10 is further provided with a material such as shredded foil 29 which is capable of serving as a source of actinic light when the lamp is flashed The envelope 10 is, of course, sealed to the cap 14 by suitable means, the material 31 shown in Fig 1 being a glass enamel produced from a glass frit. The envelope which is used in the making of the lamps may of course, be made of any gas impervious material which is sufficiently transparent to permit the transmission of light which is produced therein It should, of course, be of such characteristics that will enable it to be used without fear of flying fragments resulting from the burning of the materials within the lamp at the time the light is being produced therein For this 20) reason when glass is used as the enclosing envelope it has been found advisable to coat the outside of the glass with a clear lacquer. indicated by 32, which will at least serve to bind the fragments, even though the envelope itself cracks due to the heat and pressure developed during the rapid burning of the materials producing the light. The tubular shape which is made use of in accordance with this invention makes it possible to provide a greater volume of the necessary oxygen within the lamp than would be possible if a lamp having a similar outside proportions were used, but were further provided with a restricted portion such as is usually customary with the flash lamps of the prior art which are provided with a restricted neck fitting into the socket It has been found that lamps which have the design above shown can further be manufactured with the gas pressures within the lamp greater than those normally used in the lamps of the prior art For the most part the lamps of the prior art usually contain oxygen at a pressure of a bit more than 2/3 of an atmosphere Lamps of the design shown herein can readily be made with internal pressures ranging up to 2 atmospheres while still maintaining the necessary safety factor The lamp as shown in Fig 1 is substantially elongated A more accurately proportioned lamp is shown in Fig 2 of the drawing which illustrates the manner of fabricating these lamps, this lamp having an overall length of about 14 inch ( 45 mnm) and a diameter of about 21/32 inch ( 17 mm). The metal material for the base cap 14 can be chosen from a wide variety of materials If a direct seal is made between the envelope 10 and the base cap 14 it is, of course, preferable to make use of a material w Zhich will lend itself to this purpose, such as a recognized glass-to-metal sealing alloy. M any materials are known to the prior art.

The material can be so chosen as to have a coefficient of contraction greater than the bulb, or in the manufacture of the lamp a differential cooling schedule can be effected, so that from a temperature representing the set point of the enamel to the room temperature the material has an effective higher co 70 efficient of contraction than the bulb This will result in a radial compression type of seal of cap flange around the bulb An example of a metal which is suitable for use for this purpose is Sylvania's Alloy No 475 which is composed of 38 to 45 ' nickel, 3 to 15 >,- chromium, O 1 to 2 %o aluminium, zirconium or calcium and the remainder iron When glass frit is used in making the seal cold rolled steel can be used 80 There are, of course a number of techniques which may be used to make lamps which structurally resemble the flash lamp shown in Fig l of the drawings A preferred method of doing this is to first weld 85 the electrode 26 to the inside of the base cap 14 and then, in those cases in which cold rolled steel is used rather than a glass-tometal sealing alloy to coat the inside surface particularly the inside wall surface with a 90 glass frit The outside of the depression 16 in the end of the base cap 14 should also be so coated whereupon the button 18 to which the wire lead 24 has previously been centrally attached is placed within the seat and 9 a the assembly placed within a furnace In the furnace the temperature of the assembly can be raised to the fusion point of the glass frit so as to form a glass enamel layer over the inner end surface of the base cap (or, if pre 100 ferred, over the entire inner surface of the cap), a glass seal between the button 18 and the bottom of the base cap 14 and a glass seal at the point at which the wire lead 24 passes through the centrally positioned open 105 ing in the cap This cap assembly is then ready for the welding of a filament 30 across the leads 24 and 26 and the application of the ignition paste 28, which usually has a zirconium powder base 110 After the material which is to provide the source of actinic light such as shredded foil 29 has been filled into the envelope 10, the cap assembly which has been prepared in accordance with the previously described 113 method can be mounted on a metallic rod such as is shown at 40 in Fig 2 of the drawing The envelope containing the shredded foil can then be loosely seated within the tubular side wall of the base cap 14 where 120 upon a hood-like member 42 is placed over the glass tubular area This hood-like memnber 42, as shown in Fig 2 of the drawing, is provided with a spring 44 extending upwardly from its top surface This spring 125 is made sufficiently long to enable it to engage the 'f OD of a bell Ha -i e oemb which is then placed on top of the spring and pressed downwardly so as to hold the tubular member 10 firmly against the supported 130 785,690 cap 14 When in this position the bell jarlike member 50 is seated on a resilient ring 52 and is pulled

downwardly thereon toward an annular seat 54 by means of a screwthreaded member 56 provided with an inwardly projecting flange 58 which engages an outwardly projecting flange 60 of the bell jar-like member 50. When the device has been assembled as indicated above the lamp is located in an hermetically sealed chamber which is connected to the outside through a series of holes 62 provided in the bottom end of the rod 40, which is tubular at this point, and a bore in a tubular member 64 which passes through the member 54 but is hermetically sealed thereto This tubular member 64, as shown in the drawing, leads to a crossshaped member 71, one leg 72 of which is connected to a vacuum pump, another 74 to a source of oxygen gas, a third leg 76 to a gauge and the fourth to the tube 64 The legs 72 and 74 are connected to the pump and source respectively through valves (not shown) which can be so regulated as to cause all the air to be withdrawn from within the chamber after which oxygen gas at any desired pressure can be introduced therein. The pressure which has to date been found to be particularly suitable is one in the neighbourhood of 1 6 atmospheres When this oxygen pressure has been reached a radio frequency coil 70, which is shown surrounding the bell jar-like member 50 at a point close to the base cap 40, is activated. When this is done the annular layer of glass enamel on the inner side wall of the base cap is caused to soften, wetting the envelope 10, after which the lamp is permitted to cool. If this is done under the proper time temperature conditions a good glass-enamel-metal seal is formed between the envelope and the cap and the flash lamp can be withdrawn from within the member 50 and is now ready for use. In practising this sealing technique using radio frequency energy applied to the side wall of the base cap it is, however, extremely necessary to provide some means for holding the heat to a desired area of the cap Otherwise, therewould be a tendency for the glass seal which has been formed between the button 18 and the base cap 14 to crack, or at the very least become gas pervious Furthermore, means must be provided to hold the heat as close as possible to the bottom of the cap and the part of the envelope to which the cap is being sealed, and away from the remainder of the envelope, for two purposes Firstly the appearance of the glass tubular envelope may be spoiled if the heat were to be allowed to cause the envelope to be deformed and secondly to keep the heat away from the ignition paste for fear of producing pre-ignition and therefore a worthless lamp The rod 40 as shown in Fig 2 of the drawing has been provided to act as a means for withdrawing heat from the base cap at a sufficiently rapid rate to

prevent the melting of the part of the glass 70 enamel layer immediately adjacent the button 18 To accomplish this a good heat conducting material is chosen with a sufficiently massive structure to permit adequate heat conduction from this critical area The 75 member 42 besides serving to hold the tube firmly pressed against the cap member also serves as a heat shield This member is preferably caused to extend downwardly to a point which is slightly below the top level of 80 the base cap, thus helping to isolate the direct radio frequency energy which is absorbed by the base cap 14, so that the heat is directed to the part of the lamp where it will do the most good in melting the glass 85 enamel and causing a direct glass-to-metal seal at the desired points In a way it also serves as a heat shield and instrument for dissipating heat from undesired areas. The projecting edge of the cap 14 not only 90 adds strength to the structure and thereby permits the use of relatively thin metal stock, but also serves as a means to help localize the heat during the sealing operation Since the edge projects a slight dis 95 tance farther out from the centre than does any other part of the lamp it is closest to the coil 70 and therefore serves as the locus for the radio frequency energy. Projection lamps which use a neutral 100 atmosphere can also be made in accordance with the fundamental principles of the method herein described The characteristics of such lamps are also improved by such increase in pressure since it assists in dissi 105 pating the heat given off during operation and also tends to decrease the vapour pressure of the tungsten filament Both of these factors, of course, beneficially affect the life characteristics of the lamp 110 While the above description and drawings submitted herewith disclose a preferred and practical embodiment of the photoflash lamp of this invention it will be understood tchat the specific details of construction and 115 arrangement of parts as shown and described are by way of illustration and are not to be construed as limiting the scope of the invention. There is described and claimed in our 120 copending application No 3615/55 (Patent No 785,689) a method of making a pressure filled lamp including fitting a metallic cap over an open end of a lamp envelope, introducing the assembled components into a 125 chamber where atmosphere can be controlled and in which the tube envelope is surrounded by a metallic hood shielding the tube envelope and its contents against the application thereto of high frequency energy, 130 785,690 and heating the metallic cap by high frequency energy to form a gas-impervious seal between the metallic cap and tube envelope.

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* GB785691 (A)

Description: GB785691 (A) ? 1957-11-06

Improvements in or relating to apparatus for transporting and packagingperforated objects


COMPLETE SPECIFICATION Improvements in or relating to Apparatus for Transporting and Packaging Perforated Objects We, AVIATION DEVELOPMENTS LIMITED, of Kingsbourne House, 229-231, High Holborn, London, W.C.l, a British Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement This invention relates to packaging machines, and particularly to machines for packaging perforated objects, such as tubular or perforated rivets and the like. In industries which fabricate structures from sheet metal and especially in the airframe industry, the various parts of the structure frequently are fastened together by means of rivets. Often the structure is such that the conventional riveting method wherein a riveting tool is used at either end of the fastening rivet is impractical if not impossible. A number of ingenious rivets and riveting devices have been developed to meet this problem. One type of rivet has an axial bore or perforation extending lengthwise through the rivet and is fastened by means of a special riveting machine having a rod upon which the rivet is threaded and an enlarged end which may be withdrawn through the hole in the rivet, thereby distending and expanding the rivet. The necessity of aligning and orienting each rivet individually as it

is taken from a bulk container in order to thread the rivet on the rod of the riveting machine has hitherto been a tedious and time-consuming job. The present invention makes possible the economical production of a package in which the individual rivets are held so that their perforations are maintained substantially in alignment. and the rivets are oriented uniformly with respect to head and shank position. Therefore, it is possible to load the rod of a riveting machine by simply threading the rod through the aligned rivets in the package and then stripping away the package. The number of rivets in each package may be varied to meet the requirements of different riveting machines so that each package provides the number of rivets required to load the tool. In accordance with the invention an apparatus for transporting perforated objects, comprises a transport wire on which the objects are threaded, the wire having a receiving portion and a loop portion, and a drive reel rotatably mounted within the loop portion to impel the perforated objects along the loop portion. In accordance with another aspect of the invention a machine for packaging perforated objects is provided which includes a floating transport wire, comprising a receiving portion, a loop portion and a mandrel portion, means for threading one by one a plurality of perforated objects onto the receiving portion, a drive reel mounted adjacent the loop portion to impel the objects along the loop portion, and wrapping means disposed about the mandrel. The wrapping means are such that the perforations of the packaged objects are held substantially in alignment. In one embodiment of the invention for packaging rivets or the like, a floating transport wire includes a receiving portion a transfer loop portion and a mandrel portion in one continuous wire. A threading means picks up rivets one by one from a chute and threads the rivets onto the receiver. The chute is connected to apparatus for supplying rivets one by one which may be a conventional vibratory feeder. A drive reel comprising a pair of rings connected by reel bars rotates within the transfer loop to impel the threaded rivets from the receiver to the mandrel. The wrapping means of the preferred form of packaging machine comprises a train of wrapping material folders and pairs of packs age-forming rollers. The rollers and folders are arranged so that the mandrel portion of the transport wire conducts the rivets through or between the folders or rollers, affording a mandrel for them to work upon as the rollers draw wrapping material continuously from a supply roll. A shearing assembly is synchronized with the motion of the rollers to cut the continuous strip of packaged rivets into sections containing a

desired number of rivets. These features and other advantages of the invention are more fully described in the following detailed description and accompanying drawing, in which : Fig. 1 is a front elevation of a preferred embodiment of the invention; Fig. 2 is a sectional elevation of the receiver taken along line 2-2 of Fig. 1; Fig. 3 is a sectional elevation of the floating transport mechanism taken along line 3-3 of Fig. 1; Fig. 4 is a perspective view of a portion of the drive reel and transport wire of the invention; Fig. 5 is a sectional view of the transport mechanism taken along line 5-5 of Fig. 3; Fig. 6 is a transverse sectional elevation of the package-forming train taken along line W6 of Fig. 1; Fig. 7 is a bottom plan section taken along line 7-7 of Fig. 6; Fig. 8 is a bottom plan section taken along line 8-8 of Fig. 6; Fig. 9 is a plan section taken along line 9-9 of Fig. 1; Fig. 10 is a plan section taken along line 10-10 of Fig. 1; and Fig. 11 is a fragmentary view, partly in section, of a package formed by the illustrative embodiment of the invention. Figs. 1 through 10 illustrate one form of the present invention for packaging rivets, or the like, which may be driven by some suitable means, such as an electric motor (not shown) coupled to the driven parts of the embodiment by a conventional pulley and V-belt system (not shown). The apparatus includes a frame 20 composed of a horizontal base 21, a rear plate 22, and a front plate 23. The two plates are substantially parallel and rise vertically from the base. Rear plate 22 (Fig. 6) supports the conventional V-belt and pulley drive system, which is not illustrated. The front plate serves as a mounting means for the rivet feeding and packaging elements of the machine, and also supports the disdarge end of a rivet chute 24 (Fig. 1) which delivers a plurality of correctly oriented rivets 25, i.e., rivets in a head-up position, from suitable aligning and feeding means, such as a consectional vibratory feeder (not sllo,sm). A driven shaft 26 extends through both vertical plates and turns a threading wheel 27 which is fixed on the shaft. The threading wheel comprises a flanged hub 28 and a plurality of radial fingers 29 that extend from a flange 28A at equal radial intervals. In the illustrative embodiment, there are eight fingers, each of which consists of two spaced spring steel strips 30, 31 (Fig. 2) which are mounted on opposite faces of the hub flange so as to converge toward their outer ends. At the outer end of each strip a concave indentation

33 is provided which corresponds to a like indentation in the opposing strip to form a cup that approximates the diameter of a rivet shank 25A shown in phantom lines in Fig. 2. The fingers lift rivets from the chute one by one as the wheel rotates counter clockwise as viewed in Fig. 1. A wedge 33 spreads the strips and then releases them so that the indentations grip the shank of the rivet in the chute due to the tension of the strips. A transport wire 34 comprising a receiver 36, a substantially helical loop 37 and a mandrel 38. is located so that each rivet gripped in a finger will be threaded onto the receiver which runs through a guide tube 39. An angle 40 bolted to the front plate supports the tube in proper position. Each rivet is presented head first, and a springloaded dog 41 (Fig. 1) mounted in the guide tube holds each succeeding rivet until the next finger threads another rivet on the receiver, displacing the rivet held by the dog upwardly along the receiver. After a sufficient number of rivets have been threaded behind it, the lead rivet enters the loop where a drive reel 42 impels it along the transport wire. The transport wire is not fastened at any point of its length and might be described as "floating". A thin-walled metallic cup 43, which houses the loop, and the drive reel which rotates within the loop, orient the wire as a whole with respect to the other components of the apparatus. The drive reel (Figs. 3 through 5) is composed of two spaced co-axial annular rings 44, 45 which are connected by a number of transverse reel bars 46. The reel rotates with the cup on a reel shaft 47 which is journalled in the front plate 23 and which is concentric with the loop. The rotation of the drive reel brings the reel bars in contact with the underside 25B of the rivet heads of the rivets that are threaded on the floating transport wire, as illustrated in Figs. 3 and 5. The bars impel the rivets around the helical loop within the cup and out through an exit guide tube 50 that surrounds the first part of the mandrel. The bars need not contact every rivet. since a contacted rivet pushes those ahead of it along the wire. The inner periphery 5 of the cup restricts the radial movement of the loop by offer ing a bearing surface to the threaded rivets. The periphery of the cup is smoothly finished so that any contact between the rivets and the cup does not impede the motion of the rivets. A semi-annular divider ring 52 is fixed to the inner periphery of the cup and is co-extensive with that portion of the helical loop that has two turns of wire. The divider prevents interlock of the traveling rivets.

The entire drive reel assembly is mounted on a rectangular base 53 that is spaced from the plate 23 by bolts and spacers such as bolts 55, 55A and spacers 54, 54A illustrated in Fig. 6. Two guide rails 56, 56A extend along the under surface of the base in a direction which is parallel to the length of the mandrel. A bracket 57 projects from the top edge of the plate 23 and holds a roll 58 of aluminium foil 59 in line with the path defined by the rails. The mandrel extends from the loop and emerges from the reel cup through the exit tube which serves as an exterior restrainer for the rivets on the mandrel. The exit tube is fixed to the cup so that its projected center line is substantially tangent to the loop of the transport wire. The lower end 60 of the exit tube protrudes slightly into a wrapping material folder 61. The bolts 62 and the spring spacers 63 hold the folder away from the front plate and in proper alignment with the mandrel. As illustrated in Fig. 7, the folder is constructed to shape the aluminium foil from a single sheet which is parallel to the front plate into a sheet which is doubled around the mandrel and its rivet load. A central former 65 in the folder prevents contact between the foil and the rivets, so that at this point the rivets on the mandrel pass through the folder without contact with the foil. A pair of package-forming rollers 66, 67 press the foil about the mandrel-guided rivets as the rivets and the foil emerge from the first folder. The rollers are substantially tangent to the mandrel and to each other at the same point, and each roller has an outer peripheral band 68 of resilient material, such as rubber, that compresses the foil about the heads of the rivets, thereby pressing the ends 59A, 59B of the double sheet together on either side of the column of rivets; A groove 69 in the metal surface of the roller aligned with the mandrel provides for distention of the resilient band at this point so as to accommodate the thickness of the rivets and the mandrel. The crosssectional configuration that the package assumes passing between the first pair of rollers can be seen in Fig. 9. A second package folder 70 and a second pair of shaping rollers 71, 72 similar to the first rollers, are aligned with the mandrel in the manner described for the first folder and roller pair. The second folder is shaped to turn the longitudinal open sides 59A, 59B of the package strip over toward the strip center, and the rollers compress these folded over sides into a closed seam 73 to provide a seal. Fig. 11 shows the package strip after this seal has been formed.

Where it is desired to use wrapping material which can be sealed by means of heat and pressure instead of foil, a suitable heat ing means may be added to the first pair of rollers. By this means, the open sides of the strip may be sealed by the heat and pressure, and the second folder and the second pair of rollers can be eliminated. As shown in Figs. 9 and 10, only one roller of each pair is driven. The rollers 66 and 71 are idlers that rotate on bearings 75, 76 which are in turn supported by stub shafts bolted to the front plate. Oversized mounting holes allow the position of the shafts to be adjusted to give the desired degree of pressure against the mandrel and its load. A driven shaft 77 journalled in the front plate rotates the driven roller of the second pair, and a similar shaft 78 drives the driven roller of the first pair. A nut 79 holds a flange 80 on the end of the driven shaft of this first pair and sup ports a cam plate 81 that controls the move ment of a spacer pawl 82 adjustably mounted in a spring-loaded lever 83. The lever pivots on a pin 84 carried by a bracket 85 which the first folder supports. The lever carries a cam pin 86 at its free end which rides the cam plate mounted on the driven shaft. A rotating shearing blade 87 is linked to the driven shaft 78 behind the front plate by means not shown. Rotation of the roller shaft 78 causes the cam plate to depress the pawl 82 into the path of the mandrel-guided rivets, thereby pinching the packaging material and creating an increment of pack age strip that contains no rivets. By properly synchronizing the shear action with the roller rotation, the shearing blade severs the package strip at the empty increment, result ing in a package containing a desired number of rivets. The shearing and rivet spacing operations

are dependent for their results on the degree of synchronization between the various driven components. One arrangement that has proven successful entails rotating the threading wheel at 60 r.p.m. while the drive reel turns at 17 r.p.m. At these speeds the rollers are driven at 11.7 r.p.m. which pro vides a proper relationship between the rivet feed speed and the wrapping material travel. These settings allow the apparatus to pack age 480 rivets per minute. It can be appreciated that the invention is broad enough in scope to encompass the handling of a large variety of tubular or perforated objects in addition to perforated rivets. In our specification No. 739/57 (Serial No. 785,692) we claim a machine for packaging perforated objects so that the perforations are held substantially in alignment, includes ing the combination of, a mandrel, means threading perforated objects to be packaged on the mandrel, folding means disposed adjacent the mandrel for folding a sheet of packaging material around the mandrel, and a pair cf forming rollers disposed on opposite sides of the mandrel for compressing the folded packaging material around the perforated objects. What we claim is : - 1. Apparatus for transporting perforated objects, comprising a transport wire on which the objects are threaded, the wire having a receiving portion and a loop portion, and a drive reel rotatably mounted adjacent to the loop portion to impel the perforated objects along the loop portion. 2. Apparatus for transporting perforated objects, comprising a transport wire on which the objects are threaded, the wire having a receiving portion and a loop portion, and a drive reel rotatably mounted within the loop portion to impel the perforated objects along the loop portion. 3. Apparatus, as claimed in any of the preceding claims, including means for threading perforated objects one by one on the receiving portion of the transport wire. 4. Apparatus, as claimed in Claims 2 and 3, wherein the loop portion consists of at least one turn and the transport wire is maintained in position by a drive reel disposed coaxially within the loop. 5. Apparatus as claimed in any of the preceding Claims 2-4, wherein the transport wire comprises a helical loop portion which is surrounded by a cylindrical cup with which the drive reel is in substantially coradial relationship.

6. Apparatus, as claimed in any of the preceding claims. in which the perforated objects are impelled from the loop portion of or the transport wire to a mandrel portion of the transport wire, including a folding means disposed adjacent to the mandrel portion for folding a sheet of packaging material around the mandrel portion. a pair of forming rollers tangentially disposed with respect to the mandrel portion for compressing the folded sheet of packaging material around the perforated objects whereby the perforated objects are held substantially in alignment in the packaging material. 7. Apparatus in accordance with Claim 6 including shearing means disposed below the mandrel portion for dividing the folded and compressed packaging material including the perforated objects in sections. 8. Apparatus in accordance with Claim 6 in which a second folding means is disposed adjacent the mandrel portion for folding the open edges of the packaging material over, and means sealing the folded-over edges of the packaging material. 9. Apparatus in accordance with Claim 8 in which the sealing means comprises a second pair of forming rollers disposed tangentially with respect to the mandrel for compressing the folded edges of the packaging material to provide a seal. 10. Apparatus in accordance with Claim 8 including shearing means disposed adjacent the sealing means for cutting the folded, compressed and sealed packaging material including the perforated objects into sections. 11. Apparatus in accordance with Claim 9 including shearing means disposed adjacent the second set of forming rollers for cutting the folded and compressed packaging material including the perforated objects in sections. 12. A machine for packaging perforated objects including the combination of a transport wire comprising a receiving portion, a loop portion and a delivery mandrel portion, means for threading one by one a plurality of perforated objects on to the receiving portion, a drive reel rotatably mounted adjacent to the loop portion to impel the perforated objects along the loop portion, and wrapping means disposed about the mandrel portion whereby the perforated objects are packaged so that The perforations are positioned substantially in alignment. 13. Machine as set forth in Claim 12, wherein the transport wire is itself free of contact with all machine parts during operation. 14. Apparatus or machine as set forth in Claim 5 and comprising a semi-annular ring supported by the inner periphery of the cylindrical cup, said ring being disposed between those portions of the loop that are coextensive and being itself coextensive with those portions.

15. A machine, as set forth in Claims 12- 14, including package-shaping means disposed about the mandrel portion, and means wrapping the perforated objects in a continuous package while the perforated objects are supported by the mandrel portion. 16. A machine for packaging perforated objects so that the perforations are held substantially in alignment. including the combination of a transport wire comprising a receiving portion, a helical loop. and a mandrel portion, means for threading one by one a plurality of perforated objects on the receiving portion of the transport wire. a drive reel rotatably mounted within the helical loop. a first wrapping material folder, a first pair of package-shaping rollers. a second wrap

* GB785692 (A)

Description: GB785692 (A) ? 1957-11-06

Improvements in or relating to apparatus for packaging perforated objects


COMPLETE SPECIFICATION Improvements in or relating to Apparatus for Packaging Perforated Objects We, AVIATION DEVELOPMENTS LIMITED, of Kingsbourne House, 229-231, High Holborn, London, W.C.1, a British Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to packaging machines, and particularly to machines for packaging perforated objects, such as tubular or perforated rivets and the like. In industries which fabricate structures from sheet metal and especially in the airframe industry, the various parts of the structure frequently are fastened together by means of rivets. Often the structure is such that the conventional riveting method wherein

a riveting tool is used at either end of the fastening rivet is impractical if not impossible. A number of ingenious rivets and riveting de vices have been developed to meet this problem. One type of rivet has an axial bore or perforation extending lengthwise through the rivet and is fastened by means of a special riveting machine having a rod upon which the rivet is threaded and an enlarged end which may be withdrawn through the hole in the rivet, thereby distending and expanding the rivet. The necessity of aligning and orienting each rivet individually as it is taken from a bulk container in order to thread the rivet on the rod of the riveting machine has hitherto been a tedious and time-consuming job. The present invention makes possible the economical production of a package in which the individual rivets are held so that their perforations are maintained substantially in alignment, and the rivets are oriented uni formly with respect to head and shank position. Therefore, it is possible to load the rod of a riveting machine by simply threading the rod through the aligned rivets in the package and then stripping away the package. The number of rivets in each package may be varied to meet the requirements of different riveting machines so that each package provides the number of rivets required to load the tool. In accordance with the invention a machine for packaging perforated objects so that the perforations are held substantially in alignment, includes the combination of a mandrel, means threading perforated objects to be packaged on the mandrel, folding means disposed adjacent the mandrel for folding a sheet of packaging material around the mandrel, and a pair of forming rollers disposed on opposite sides of the mandrel for compressing the folded packaging material around the perforated objects. Furthermore, in accordance with the invention a second folding means is disposed adjacent the mandrel for folding the open edges of the previously folded packaging material over, and a second pair of forming rollers which are disposed on opposite sides of the mandrel for compressing the folded edges of the packaging material to provide a seal.

For a better understanding of the invention reference may be had to the following detailed description taken in conjunction with the accompanying drawings in which: Fig. 1 is a front elevation of a preferred embodiment of the invention; Fig. 2 is a sectional elevation of the receiver taken along line 2-2 of Fig. 1; Fig. 3 is a sectional elevation of the floating transport mechanism taken along line 3-3 of Fig. 1; Fig. 4 is a perspective view of a portion of the drive reel and transport wire of the invention; Fig. 5 is a sectional view of the transport mechanism taken along line 5-5 of Fig. 3; Fig. 6 is a transverse sectional elevation of the package-forming train taken along line 6-6 of Fig. 1; Fig. 7 is a bottom plan section taken along line 7-7 of Fig. 6; Fig. 8 is a bottom plan section taken along line 8-8 of Fig. 6; Fig. 9 is a plan section taken along line 9-9 of Fig. 1; Fig. 10 is a plan section taken along line 10-10 of Fig. 1; and Fig. 11 is a fragmentary view, partly in section, of a package formed by the illustrative embodiment of the invention. Figs. 1 through 10 illustrate one form of the present invention for packaging rivets, or the like, which may be driven by some suitable means, such as an electric motor (not shown) coupled to the driven parts of the embodiment by a conventional pulley and V-belt system (not shown). The apparatus includes a frame 20 composed of a horizontal base 21, a rear plate 22, and a front plate 23. The two plates are substantially parallel and rise vertically from the base. Rear plate 22 (Fig. 6) supports the conventional V-belt and pulley drive system, which is not illustrated. The front plate serves as a mounting means for the rivet feeding and packaging elements of the machine and also supports the discharge end of a rivet chute 24 (Fig. 1) which delivers a plurality of correctly oriented rivets 25, i.e., rivets in a head-up position, from suitable aligning and feeding means, such as a conventional vibratory feeder (not shown). A driven shaft 26 extends through both vertical plates and turns a threading wheel 27 which is fixed on the shaft. The threading wheel comprises a Banged hub 28 and a plurality of radial fingers 29 that extend from a flange 28a at equal radial intervals. In the illustrative embodiment, there are eight fingers, each of which consists of two spaced spring steel strips 30, 31 (Fig. 2) which are mounted on opposite faces of the hub flange so as to converge toward

their outer ends. At the outer end of each strip a concave indentation 32 is provided which corresponds to a like indentation in the opposing strip to form a cup that approximates the diameter of a rivet shank 25a shown in phantom lines in Fig.2. The fingers lift rivets from the chute one by one as the wheel rotates counterclock-svise as viewed in Fig. 1. A wedge 33 spreads the strips and then releases them so that the indentations grip the shank ofthe rivet in the chute due to the tension of the strips. A transport wire 34, comprising a receiver 36, a substantially helical loop 37 and a mandrel 38, is located so that each rivet gripped in a iinger will be threaded onto the receiver which flints through a guide tube 39. An angle 40 bolted to the front plate supports the tube in proper position. Each rivet is presented head first, and a spring-loaded dog (Fig. 1) mounted in the guide tube holds each succeeding rivet until the finger threads another rivet on the receiver, displacing the rivet held by the dog upwardly along the receiver. After a sufficient number of rivets have been threaded behind it, the lead rivet enters the loop where a drive reel 42 impels it along the transport wire. The transport wire is not fastened at any point of its length and might be described as floating". A thin-walled metallic cup 43, which houses the loop, and the drive reel which rotates within the loop, orient the wire as a whole with respect to the other components of the apparatus. The drive reel (Figs. 3 through 5) is composed of two spaced co-axial annular rings 44. 45 which are connected by a number of transverse reel bars 46. The reel rotates within the cup on a reel shaft 47 which is journalled in the front plate 23 and which is concentric with the loop. The rotation of the drive reel brings the reel bars in contact with the underside 25b of the rivet heads of the rivets that are threaded on the floating transport wire, as illustrated in Figs. 3 and 5. The bars impel the rivets around the helical loop within the cup and out through an exit guide tube 50 that surrounds the first part of the mandrel. The bars need not contact every rivet, since a contacted rivet pushes those ahead of it along the wire. The inner periphery 51 of the cup restricts the radial movement of the loop by offering a bearing surface to the threaded rivets. The periphery of the cup is smoothly finished so that any contact between the rivets and the cup does not impede the motion of the rivets. A semi-almular divider ring 52 is fixed to the inner periphery of the cup and is co-extensive with that portion of the helical loop that has two turns of wire. The divider prevents interlock of the travelling

rivets. The entire drive reel assembly is mounted on a rectangular base 53 that is spaced from the plate 23 by bolts and spacers such as bolts 55, 55a and spacers 54, 54a illustrated in Fig. 6. Two guide rails 56, 56a extend along the under surface of the base in a direction which is parallel to the length of the mandrel. A bracket 57 projects from the top edge of the plate 23 and holds a roll 58 of aluminium foil 59 in line with the path defined by the rails. The mandrel extends from the loop and emerges from the reel cup through the exit tube which serves as an exterior restrainer for the rivets on the mandrel. The exit tube is fixed to the cup so that its projected centre line is substantially tangent to the loop of the transport wire. The lower end 60 of the exit tube protrudes slightly into a wrapping material folder 61. The bolts 62 and the spring spacers 63 hold the folder away from the front plate and in proper alignment with the mandrel. As illustrated in Fig. 7, the folder is constructed to shape the aluminium foil from a single sheet which is parallel to the front plate into a sheet which is doubled around the mandrel and its rivet load. A central former 65 in the folder prevents contact between the foil and the rivets, so that at this point the rivets on the mandrel pass through the folder without contact with the foil. A pair of package-forming rollers 66, 67 press the foil about the mandrel-guided rivets as the rivets and the foil emerge from the first folder. The rollers are substantially tangent to the mandrel and to each other at the same point, and each roller has an outer peripheral band 68 of resilient material, such as rubber, that compresses the foil about the heads of the rivets, thereby pressing the ends 59a, 59b of the double sheet together on either side of the column of rivets. A groove 69 in the metal surface of the roller aligned with the mandrel provides - for distention of the resilient band at this point so as to accommodate the thickness of the rivets and the mandrel. The cross-sectional configuration that the package assumes passing between the first pair of rollers can be seen in Fig. 9. A second package folder 70 and a second pair of shaping rollers 71, 72 similar to the first rollers, are aligned with the mandrel in the manner described for the first folder and roller pair. The second folder is shaped to turn the longitudinal open sides 59a, 59b of the package strip over toward the strip center, and the rollers compress these folded-over sides into a closed seam 73 to privide a seal. Fig. 11 shows the package strip after this seal has been formed. Where it is desired to use wrapping material which can be sealed by means of heat and pressure instead of foil, a suitable heating means

may be added to the first pair of rollers. By this means, the open sides of the strip may be sealed by the heat and pressure, and the second folder and the second pair of rollers can be eliminated. As shown in Figs. 9 and 10, only one roller of each pair is driven. The rollers 66 and 71 are idlers that rotate on bearings 75, 76 which are in turn supported by stub shafts bolted to the front plate. Oversized mounting holes allow the position of the shafts to be adjusted to give the desired degree of pressure against the mandrel and its load. A driven shaft 77 journalled in the front plate rotates the driven roller of the second pair, and a similar shaft 78 dives the driven roller of the first pair. A nut 79 holds a flange 80 on the end of the driven shaft of this first pair and supports a cam plate 81 that controls the movement of a spacer pawl 82 adjustably mounted in a spring-loaded lever 83. The lever pivots on a pin 84 carried by a bracket 85 which the first folder supports. The lever carries a cam pin 86 at its free end which rides the cam plate mounted on the driven shaft. A rotating shearing blade 87 is linked to the driven shaft 78 behind the front plate by means not shown. Rotation of the roller shaft 78 causes the cam plate to depress the pawl 82 into the path of the mandrel-guided rivets, thereby pinching the packaging material and creating an increment of package strip that contains no rivets. By properly synchronizing the shear action with the roller rotation, the shearing blade severs the package strip at the empty increment, resulting in a package containing a desired number of rivets. The shearing and rivet spacing operations are dependent for their results on the degree of synchronization between the various driven components. One arrangement that has proven successful entails rotating the threading wheel at 60 r.p.m. while the drive reel turns at 17 r.p.m. At these speeds the rollers are driven at 11.7 r.p.m. which provides a proper relationship between the rivet feed speed and the wrapping material travel. These settings allow the apparatus to package 480 rivets per minute. It can be appreciated that the invention is broad enough in scope to encompass the handling of a large variety of tubular or perforated objects in addition to perforated rivets. In our Specification 3727/55 (Serial No. 785,691) we claim an apparatus for transporting perforated objects, comprising a transport wire on which the objects are threaded, the wire having a receiving portion and a loop portion, and a drive reel rotatably mounted adjacent to the loop portion to impel the perforated objects along the loop portion. W5lat we claim is: 1: A machine for packaging perforated objects so that the perforations

are held substantially in alignment, including the combination of, a mandrel, means threading perforated objects to be packaged on the mandrel, folding means disposed adjacent the mandrel for folding a sheet of packaging material around the mandrel, and a pair of forming rollers disposed on opposite sides of the mandrel for compressing the folded packaging material around the perforated objects. 2. Apparatus in accordance with Claim 1, in which a second folding means is disposed adjacent the mandrel for folding the open edges of the previously folded packaging material over, and a second pair of forming rollers which are disposed on opposite sides to the mandrel for compressing the folded edges of the packaging material to provide a seal. 3. A machine for packaging perforated objects including the combination of, a mandrel,

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