* GB784768 (A) Description: GB784768 (A) No title available Description of GB784768 (A) COMPLETE SPECIFICATION Improvements in or relating to the Balancing of Dynamically Unbalanced Bodies. We, GENERAL MOTORS CORPORATION, a Company incorporated under the laws of the State of Delaware in the United-States of America, of Grand Boulevard in the City of Detroit, State of Michigan, in the United States of America (Assignees of JOSEPH F. LAsN) - -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 the balancing of dynamically unbalanced bodies such as crank-shafts. From one aspect the invention is an apparatus for automatically determining the magnitude and angular location of unbalance in a dynamically unbalanced body and from another aspect the invention is an apparatus for automatically determining the magnitude and angular location of the unbalance in a dynamically unbalanced body, in-association with means for automatically correcting such unbalance. The invention is particularly suitable for use in engine assembly or finish balancing installations in which the crankshaft is automaticalfy checked for unbalance when installed in an engine and any unbalance in the shaft, as well as such unbalance as may be contributed thereto by the other components of the engine associated with the shaft, is automatically corrected in the assembled condition of the engine. The invention has among its general objects to provide such apparatus in accordance with the above which is characterised by extreme
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* GB784768 (A)
Description: GB784768 (A)
No title available
Description of GB784768 (A)
COMPLETE SPECIFICATION
Improvements in or relating to the Balancing of Dynamically Unbalanced
Bodies.
We, GENERAL MOTORS CORPORATION, a Company incorporated under the laws
of the
State of Delaware in the United-States of
America, of Grand Boulevard in the City of
Detroit, State of Michigan, in the United
States of America (Assignees of JOSEPH F.
LAsN) - -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 the balancing of dynamically unbalanced
bodies such as crank-shafts.
From one aspect the invention is an apparatus for automatically
determining the magnitude and angular location of unbalance in a
dynamically unbalanced body and from another aspect the invention is
an apparatus for automatically determining the magnitude and angular
location of the unbalance in a dynamically unbalanced body,
in-association with means for automatically correcting such unbalance.
The invention is particularly suitable for use in engine assembly or
finish balancing installations in which the crankshaft is
automaticalfy checked for unbalance when installed in an engine and
any unbalance in the shaft, as well as such unbalance as may be
contributed thereto by the other components of the engine associated
with the shaft, is automatically corrected in the assembled condition
of the engine.
The invention has among its general objects to provide such apparatus
in accordance with the above which is characterised by extreme
simplicity of construction and of operation and, yet, is possessed of
sufficient sensitivity and accuracy required for high production
balancing installations.
A dynamic unbalance determination apparatus according to the invention
enables automatic determination of both the magnitude and the angular
location of unbalance to be made without requiring an operator to
adjust dials, read instruments and interpret readings.
The scope of the invention is indicated by the appended claims; and
how it can be performed is hereinafter particularly described with
reference to the accompanying drawing which shows diagrammatically an
automatic dynamic unbalance determination apparatus and associated
balance correction apparatus in accordance with the present invention.
In the drawing, 10 is an engine which has a crankshaft 12 and is
mounted with the sump cover removed in an oscillatable engine cradle
14. 16 is a constant speed electric drive motor, the shaft 18 of which
carries a wheel 20 and is suitably coupled to the engine crankshaft 12
to rotate the latter in the cradle or stand. 22 and 24 are vibration
pickups each of which is associated with an unbalance magnitude and
location determination apparatus and an element of an unbalance mag-
nitude correction device in accordance with the present invention,
only one set of the unbalance determination apparatus and the element
of anunbalance magnitude correction device for one of the pickups
being shown in the drawing.
The engine stand or cradle 14 is of a kind employed in conventional
balancer installations and is mounted on resilient or oscillatable
supports while permit movement of the cradle and engine due to
unbalance effects in either end of the crankshaft in an axial plane of
the shaft and the vibration pickups. In accordance with conventional
balancing practice, the crankshaft is coupled to the shaft 18 of the
drive motor through a coupling arrangement such as the pair of spaced
universal joints shown at 30.
The vibration pickups 22 and 24 are mounted transversely to the axis
of the crankshaft and at axially spaced points along the length of the
cradle 14 corresponding to the mechanical nodal points of the
unbalance forces at the respective ends of the crankshaft The pickups
22, 24 are conventional electromagiieetic devices each of which
generates an alternating current signal and, by reason of said nodal
point mounting, are unaffected by the unbalance influence of the
opposite end of the crankshaft. The alternating current signal from
each of the pickup devices 22, 24 has a frequency equal to the
rotational speed at which the crankshaft is driven and an amplitude
proportional to the total unbalance effect produced by the end
of the crankshaft adjacent the pickup. Each pickup signal further
includes a phase displacement characteristic related to the angular
location of the total unbalance from a fixed reference point on the
surface of the shaft and
contained in a transaxial correction plane extending through an end
counterweight of
the crankshaft, there being two such correc
tion planes, one at each end of the shaft.
Pickup 22, together with the apparatus
associated therewith, is adapted, therefore, to
sense the characteristics of unbalance at the
left end of the shaft and has its output ampli
fied in an amplifier 34 the output of which is
applied through conductors 36, 38 to a first
chopper or unbalance angle relay contactor
device 40 which includes a transformer 42
having a primary winding 44 connected to
conductors 36, 38 and a centre-tapped
secondary winding 46 associated with a relay
48 having a pair of stationary contacts 50, 52
and a movable switch arm 54 operable be
tween said contacts by an energisable relay
coil 56.
Relay coil 56 is connected for energisation
in a circuit which is alternately completed and
interrupted by one of a pair of circuit
interrupting switches S-l and S-2 of a contact
mechanism which is indicated generally at 64
and comprises a pair of rotatable axially
spaced cam elements 66, 68 oriented 90
degrees in space relative to one another and
mounted on a shaft 69 coupled to the drive
motor 16 and driven in synchronism with the
crankshaft 12. Each cam 66, 68 has asso
ciated therewith a pair of circuit contacts 70,
72 and 74, 76 which are stationary relative to
the cams and are alternately closed and
opened during each revolution of the shaft
69. Suitable ganged means 78 associated with
the cams 66, 68 and including a control knob
80 is provided for angular displacing the
cams relative to their contacts so as to alter
the commencement of the half period during
which the contacts 70, 72 and 74, 76 are closed
and opened relative to the fixed reference
point on the crankshaft.
The energising circuit for relay coil 56 in
cludes conductor 82, a source of power such
as battery 84, conductor 86, contacts 70, 72
and conductor 88. The movable switch arm
54 of the relay 48 is thus alternately moved
between its contacts 50, 52 to provide a
reversing or commutating action of the ampli
fied pickup signal. This commutated signal
appears in the output of the unbalance angle relay contactor device 40
between conductors
90 and 92, which are connected to switch arm
54 and the centre tap of the transformer
secondary winding, respectively, and may be
displayed on a zero centre D,C. milliameter
94 connected between conductors 90 and 92.
Rotation of the control knob 80 to adjust the
position of the cams 66 and 68 with respect to
the crankshaft 12 will cause the amplitude of
the full wave rectified signal displayed on
meter 94 to vary from zero to maximum. The
control knob 80 is provided with angular
graduations thereon so that its angular dis
placement relative to a reference pointer 96
on a stationary panel or the frame 98 of the
contact mechanism 64 may be read for a zero
or null reading of meter 94 as an indication of
the angular location of the unbalance in the
- left end of the crankshaft. While the knob
80 may be adjusted by an operator to effect
a null reading of the meter as in an open loop
step sequence system, it is preferred to employ
automatic positioning of the contact mech
anism, as will be described.
The amplitude or magnitude of the total
unbalance at the left end of the shaft is
determined by applying the amplified pickup
signal appearing at the output of amplifier 34
to a second chopper or unbalance amplitude
relay contactor device 100 which is similar to
chopper 40 and includes a transformer 102
having a primary winding 104 and a centre)
tapped secondary winding 106 and a relay
108 with a switch arm 110 movable between
a pair of stationary contacts 112 and 114 by an
energisable actuator coil 116. Actuator coil
116 is contacted in an energisable circuit :
which includes conductor 118, battery 120,
conductor 122, contacts 74, 76 of contact
mechanism 64 and conductor 124.
The commutated output of the second
chopper 100 is taken from the centre tapped]
winding 106 and switch arm 110 and applied
as a full wave rectified signal through conduc
tors 130, 132 to a closed loop servo controlled
amplitude comparison circuit which auto
matically indicates the magnitude of the un-i
balance quantity and positions an adjustable
drill stop setting element 134 of a balance
correction drilling apparatus associated with
the unbalance determination apparatus to
effect exact compensation for the amount of :
the unbalance at the left end of the shaft. The
amplitude comparison and drill stop position
ing apparatus includes a conventional servo
amplifier 136 and its associated two-phase
servo positioning motor 138 and a poten-:
tiometer arrangement comprising the ad
justable resistor 140 connected across a fixed.
known reference source of balance voltage.
shown as battery 142. The output of the
second chopper 100 is connected in series with the input of the servo
amplifier and the portion of the output of the.potentiometer appearing
between conductor 132 and the adjustable arm 144 of the potentiometer
resistor 140, which is mechanically coupled to the shaft 146 of the
servo motor 138.
One of the phase windings of the servo motor 138 is connected for
energisation from a local alternating current source of supply and the
other quadrature phase winding thereof is connected for energisation
by a control signal, which appears at the output of the servo
amplifier 136 and corresponds to the amplitude difference between the
output of the chopper 100 and the potentiometer. The resulting
differential control signal is of such magnitude and polarity as to
tend to rotate the- unbalance servo motor 138 in a direction and by an
amount such as to reduce the error or control signal to zero, -at
which point the amplitude comparison system will be balanced and the
motor or translating device will cease moving.
An indicator in the form of-a graduated indicator dial, which may be
provided on, say; the stator casing of the servo motor 138, and a
pointer carried by the shaft 146 may be employed to indicate the
magnitude of the unbalance. The shaft 146 of the unbalance servo motor
138 is directly coupled to the drill depth control element 134 of a
balance correction drilling apparatus or equivalent balance correction
apparatus which is mounted under the engine assembly, and adjusts the
drill depth setting element automatically in accordance with the
determination af the magnitude of unbalance. It will be noted that
both the unbalance magnitude determination and the setting of the
drill control element 134 are performed automatically without human
intervention.
To provide for automatic adjustment of the knob 80 of the contact
mechanism 64, the output of the first or unbalance angle relay 40 is
applied to the input of a servo amplifier 177 of a servo positioning
system, thereby dispensing with this previously manually performed
operation. The output of the servo amplifier 177 is connected by
conductors 179 and 181 to the variably energised phase windings of an
angle positioning servo motor 183 whose rotor shaft 185 is geared to
the rotatable knob 80 of the contact mechanism 64.
The apparatus may further include still another servo positioning
arrangement for angularly positioning the handwheel 20 upon conclusion
of the unbalance determination operation to correspond to the extent
of rotation of the unbalance angle servo motor 183 when the relay
contactor 40 was adjusted to balance, and thereby to locate the
crankshaft 12 in proper relation to the balance correction apparatus.
This last-mentioned crankshaft positioning arrangementmay include a
synchro transmitter device 187, the rotor shaft 189 of wliich is
coupled to the shaft 185 of the servo motor 183; a synchro receiver
device 191 the three-phase stator winding of which is electrically
connected to the three-phase stator winding of the transmitter device
187 by conductors 193, 195, 197; a servo-amplifier 199 the input
terminals of which are connected to the rotor winding of the receiver
synchro device 191 by conductors 201 and 203; -and a two-phase power
servo positioning motor 205 the control phase winding of which is
connected to the output of the servo amplifier 199 by conductors 207
and 209. The other winding of the servo motor 205 is energised from a
local alternating current power -source. The rotor shaft 211 of this
servo positioning -motor is coupled through gearing-213 to the wheel
20 or to the crankshaft 12 itself and through gearing 217 to the shaft
of the synchro receiver in the manner of synchro-controlled servo
positioning arrangements. A switch 215 may be provided in one of the
A.C. source conductors of the position transmitter device 187 and is
adapted to be closed to energise this data transmission system-at the
conclusion of the unbalance determining cycle when the drive motor 16
stops rotating, at which time the control phase winding of the servo
motor 205 will be energised to servo position the wheel 20 in
accordance with the determined angle of unbalance location for the
left end of the shaft.
The two cams 66 and 68 of the contact mechanism 64 both move as the
servo motor 183 automatically adjusts the control knob 80 of the
contact mechanism 64 for zero or null reading on the D.C. meter 94.
The output of chopper 40 associated with the unbalance location or
angle determination portion of the apparatus is then zero while that
of chopper 100 associated with the quadrature related cam 68 of the
unbalance magnitude determining portion of the apparatus will be a
maximum. The unbalance servo motor 138 controlled from the unbalance
magnitude relay contactor 100 adjusts the drill depth control element
134, and after the drive motor has been stopped, the synchro data
transfer system 187, 191 is energised to con trol servo motor 205
which adjusts the hand wheel 20 to position the exposed counterweight
of the crankshaft, where one of the balance corrections is to be
performed, over the drill bit of the drilling apparatus mounted below
the engine stand and thereafter energises the drill motor and
transmission apparatus thereof to remove an amount of metal
corresponding to the setting of the automatically adjusted drill depth
control element 134 from the counterweight in the left end correction
plane. The operation is repeated for the right end of the shaft with
similar apparatus associated with pickup 24.
The use of the chopper integrator apparatus for the unbalance
magnitude and angle determination apparatus simplifies difficult
filtering problems that otherwise would be presented and assures that
the unbalance signal obtained from the outputs of the choppers 40,
100will be unaffected by and independent of all frequencies other than
the fundamental frequency determined by the speed of shaft 69. In
short, the choppers 40, 100 act as very narrow band pass filters.
Pickup 24 is adapted to sense unbalance effects in the right end of
the crankshaft and will have its output applied to an unbalance
determination and drill depth control apparatus including a second
contact mechanism and a second set of angle location and unbalance
magnitude choppers and associated positioning apparatus identical with
that associated with pickup 22, the illustration of which has been
omitted for simplicity of the drawing.
While the present invention has been shown and described herein as
applied to the unbalance detection and correction ofunbalance in two-
arbitrarily selected transaxial planes of correction in elongated
bodies such as crankshafts, it is apparent that the principles and
apparatus of the present invention are equally applicable to the
automatic detection and correction of unbalance in bodies in which the
unbalance is located in but a single transaxial plane.
What we claim is:
1. Apparatus for automatically determining the unbalance of a
dynamically unbalanced body, comprising a device for supporting the
body for rotation about its axis, drive mechanism including a
rotatable shaft coupled to said body for rotating it on its axis,
vibration pickup means responsive to vibrations induced by unbalance
in said body and developing a periodically varying electrical signal
having a phase and amplitude related to the angular location and
magnitude of unbalance in said body, a commutator chopper device
having an input circuit connected to said vibration pickup means and
an output circuit, a variable contact mechanism controlling the output
from said chopper device and including a cam driven by said drive
means in synchronism with said body, a pair of switch contacts adapted
to be actuated by said cam and adjustable means for changing the
position in space of said switch contacts relative to said cam, said
switch contacts being connected in circuit controlling relation with
said chopper device, and servo positioning means connected to the
output of said chopper device for automatically adjusting said
adjustable means of said variable contact mechanism.
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* GB784769 (A)
Description: GB784769 (A) ? 1957-10-16
Improvements in bead wrapping machine
Description of GB784769 (A)
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The EPO does not accept any responsibility for the accuracy of data
and information originating from other authorities than the EPO; in
particular, the EPO does not guarantee that they are complete,
up-to-date or fit for specific purposes.
PATENT SPECIFICATION
784,769 Date of Application and filing Complete Specification: Nov 28,
1955.
No 33981155.
Application made in United States of America on Dec 13, 1954.
Complete Specification Published: Oct 16, 1957.
Index at Acceptance:-Class 144 ( 1), B 4 E.
International Classification:-B 62 g.
COMPLETE SPECIFICATION
Improvements in Bead Wrapping Machine.
We, UNITED STATES RUBBER COMPANY, of Rockefeller Center, 1230 Avenue
of the Americas, New York, State of New York, United States of
America, a corporation organized and existing under the laws of the
State of New' Jersey, 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 machine intended for use in applying
rubberized tape to a bead wire bundle such as used in the manufacture
of pneumatic tires, but suitable for applying tacky tape to other
annular shaped articles.
Among the objects of the invention is to provide such a machine that
will automatically accommodate bead wire bundles of varying radial
thicknesses without the necessity of manual adjustment; which will
automatically measure and sever the tape to desired lengths; which
will automatically feed the tape to the point of application thereof
to the bead wire bundles; and which will automatically eject the bead
wire bundles from the machine upon the completion of the wrapping
thereof.
Other objects and advantages of the invention will become apparent
from the following description when read in conjunction with the
accompanying drawings wherein:
Fig 1 is a side elevational view of the machine of the invention; Fig
2 is a partial front elevational view of the machine looking in the
direction of the arrows II-II of Fig 1; Fig 3 is a top plan view of
the machine; Fig 4 is a sectional view taken on the line IV-IV of Fig
2 showing the details of the main bead driving and wrapping wheel of
the machine; Figs 5-9 are partial sectional views of portions of the
machine illustrating the sequential lPrice 3 s 6 d l operations of the
machine in wrapping a bead wire bundle; Fig 5 showing the wrapping of
three sides of the bead wire bundle; Fig 6 showing the folding of one
edge of the tape over the remaining side; Fig 7 showing the 50
stitching of the first turned edge; Fig 8 showing the folding over of
the remaining edge of the tape; and Fig 9 showing the stitching of the
second turned edge of the tape; and 55 Fig 10 is a diagram of the
fluid and electrical control system for the machine.
Referring to the drawings and in particular to Figs 1 and 2, the
intended function of the machine is to wrap a length of tacky rub 60
berized tape T (Figs 1 and 2) around a bead wire bundle or coil B (Fig
2).
BEAD WRAPPING MECHANISM The portion of the machine which performs the
wrapping of the bead B includes a bead 65 driving and wrapping wheel
10 comprising axially spaced radial flanges 10 a and 10 b between
which the bead wire bundle B is pressed in the wrapping of the tape T
therearound The wheel 10 is secured to the end 70 of a shaft 11 which
extends from the front of the machine and is journaled, as best shown
in Fig 3, in suitable bearings 12 and 13 secured respectively to
vertically extending framework plates 14 and 15 forming a part 75 of
the supporting framework for the machine.
As best shown in Figs 2 and 3, the shaft 11 and the wheel 10 secured
thereto are rotated in the direction of the arrow in Fig 2 by means of
an electric motor 16 (Fig 3) through 80 a drive including a speed
reducer 17, a pulley 18 secured to the output shaft of the speed
reducer 17, a pulley 19 secured to the shaft 11 and a belt 20
interconnecting the pulleys 18 and 19 85 As best shown in Fig 4, the
flange 10 a of the wheel 10 is secured to the end of the shaft 11 by
means of a tapered, split bushing 21 and set screws 22 The flange 10 b
has an axially projecting externally screw-threaded hub por 90 tion 23
which screws into an internally screwthreaded annular portion 23 a of
the flange l Oa This arrangement permits variation in the axial
spacing between the opposed outer peripheral surfaces of the flanges I
Oa and l Ob by rotation of flange l Ob with respect to flange la, so
that bead wire bundles B of various widths may be accommodated
therebetween The flanges 10 a and l Ob may be locked in any desired
relative rotative position by means of a pin 24 which is adapted to
extend through any of a plurality of circumferentially spaced openings
25 through the flange l Ob and an opening 26 through the flange 10 a.
An annular plate 27 having an outer peripheral axial flange 27 a is
resiliently mounted in the space between the flanges l Oa and l Ob
with the flange 27 a thereof forming a cylindrical surface against
which a bead wire bundle B positioned in the space between the outer
peripheries of the flanges l Oa and l Ob may bear as the tape T is
applied thereto.
The annular plate 27 is resiliently mounted in the space between the
flanges l Oa and l Ob by a resilient rubber ring 28, one side of which
is bonded, by the usual conventional process of bonding rubber to
metal to the plate 27 and the opposite side of which is bonded to an
annular plate 29 secured to flange l Oa by screws 29 a This resilient
mounting of the annular plate 27 permits radial displacement thereof
upon the application of a localized force to the flange 27 a thereof
by the bead wire bundle B in the application of the tape thereto so
that the bead wire bundles B of a variety of radial thicknesses can be
automatically accommodated completely within the space between the
flanges l Oa and lob, to thereby ensure proper wrapping thereof.
In the application of the tape T to the bead wire bundle B, the bead
wire bundle B, which is of a larger diameter than the wheel 10, is
placed around the wheel 10 as shown in Fig.
2 The tape T is fed onto the peripheral surface of the wheel 10 and
pressed thereagainst by a feed roller 30, as shown in Figs 2 and 4.
As the wheel 10 rotates it carries the tape T therewith and the bead
wire bundle B is pressed against a medial portion of the tape T into
the space between the flanges i O a and l Ob by a pressure roller 3 1
to wrap the tape T around three sides of the bead wire bundle B as
shown in Fig 5 The resilient mounting of the annular plate 27 permits
the complete accommodation of a segment of the bead wire bundle B in
the space between the flanges l Oa and l Ob thereby ensuring that the
bead wire bundle is completely wrapped on three sides Thereafter, as
the bead wire bundle B is rotated by the wheel 10, one edge of the
tape T is folded over the other side of the bead wire bundle by a plow
32, as shown in Fig 6, and stitched down by a stitching roller 33 as
shown in Fig 7 The other edge of the tape is then folded over by a
plow 34 as shown in Fig 8 and stitched down by a stitching roller as
shown in Fig 9.
The pressure roller 31, plow 32, stitching 70 roller 33, plow 34, and
stitching roller 35 are secured in spaced relationship to an arcuate
plate 36 (Fig 2) which in turn is secured to a slide 37 to permit
retraction thereof from the operative position as shown in Fig 2 to a
75 retracted position as shown in Fig 3 to allow loading and unloading
of the bead wire bundle from the wheel 10 The slide 37 is slidably
mounted in parallel ways 38 and 39 which are secured to framework
plate 14 and 80 is actuated by fluid actuated cylinder 40 secured to
the opposite side of the plate 14 'as shown in Fig 3 The piston rod 40
a of the cylinder 40 is secured to a plate 41 which is in turn secured
to the end of the slide 37 85 TAPE FEEDING MECHANISM The tape T for
wrapping a bead wire bundle B is supplied from a roll thereof which is
supported on a roller 42 journaled at one end in and extending from a
side framework 90 plate 14 a adjacent the base thereof as best shown
in Fig 1 The tape T is normally wrapped with a length of liner fabric
L interposed between adjacent turns of the tape to prevent sticking
together thereof A liner 95 take-up roll 43 journaled in the end of an
arm 44 pivotally suspended from a pivot pin 45 secured to the
framework plate 14 a, frictionally engages the periphery of the roll
of tape T so that as the tape is withdrawn from 100 the roll thereof,
the liner take-up roll 43 is automatically rotated to take up the
liner fabric L.
The tape T withdrawn from the roll thereof is directed around spaced
guide rollers 46, 47 105 and guide plate 49, all secured to the plate
14 a, and through a clamping and perforating mechanism 50, which as
will be described in detail hereafter, serves in severing the tape to
the proper length From the clamping and 110 perforating mechanism 50,
the tape is directed over a guide roller 51, and then around a guide
roller 52 mounted on an adjustable slide 53 mounted in ways 54 and 55
secured to the side plate 14 a and adapted to be locked 115 in
adjusted position by a lock nut 56 From the guide roller 52, the tape
is directed around a pulley 57 secured to the input shaft of a
variable speed drive 58, and around a guide roller 59, a guide plate
60, a guide roller 61, a 120 guide roller 63, a guide plate 64 (best
shown in Fig 2) and under the feed roller 30.
Adjustment of roller 52 permits varying the length of the tape between
the clamping and perforating mechanism 50 and the feed roller 125 in
accordance with the circumference of the bead wire bundles B being
wrapped The variable speed drive 58 serves as a measuring and control
device A switch actuating cam (Fig 3) is secured to the output shaft
of 130 784,769 to continue to rotate A spring press brake finger 95
engages the tape T as it passes over the guide plate 64, and prevents
the tape from retracting due to the tension therein when the feed
roller is raised and the tape severed 70 as will be hereinafter
described The finger is journaled on a pin 96 which is secured to an
extention of plate 71 While the initial feeding of the tape T is
performed by the rotation of the wheel 10 when the tape T is 75
pressed thereagainst by the feed roller 30, the tape, because of its
tackiness, is sometimes difficult to pull from the roll thereof and a_
pulley 97 (Fig 1), driven by an electric motor 98, which frictionally
engages the tape T 80 between the roll thereof and the guide roller 46
is provided to assist in pulling the tape T from the roll The electric
motor 98 is secured to the inner side of framework plate 14 a It will
be appreciated that the frictional 85 force between the pulley 97 and
the tape T and therefore the force which the pulley 97 exerts on the
tape T is dependent upon the tension in the tape T and that therefore
pulley 97 assists in pulling the tape from the 90 roll thereof only as
necessary to maintain a minimum predetermined tension G in the tape.
TAPE SEVERING MECHANISM The clamping and perforating mechanism 95 50,
best shown in Fig 1, which serves to sever the tape after the desired
length of tape has been applied to a bead wire bundle, is secured to
side plate 14 a and includes a stationary jaw 99 and a moveable
clamping 100 jaw 100 which is spring mounted by means of springs l O
Oa and l O Ob on the lower face of a moveable platen 101 which is in
turn actuated by a fluid actuated cylinder 102 The platen 101 also
carries a perforating tool 103 which 105 is adapted to move through an
opening through the floating or spring mounted jaw to perforate the
tape T across the full width thereof to thereby weaken, without
severing, the tape, at a predetermined point 110 The spring mounting
of the jaw 100 permits the clamping of the tape prior to the
perforation thereof The clamping of the tape between the jaws 99 and
100 acts as a brake on the tape to thereby tension the tape a suffi
115 cient amount to cause the tape to break or fail along a previously
perforated point thereof upon the completion of the wrapping of a bead
wire bundle The roller 52 and the variable speed drive 58 are so
adjusted that 120 the length of tape T passing through the clamping
and perforating mechanism 50 between actuations thereof is equal to
the length of tape necessary to wrap a particular bead wire bundle
Thus, the clamping of the 125 tape causes the tape to break or fail
along a previously perforated line at a point between the feed roller
30 and the pressure roller 31 whereby another bead wire bundle can be
wrapped without re-threading the tape 130 the variable speed drive 58
and serves to actuate a control switch forming a part of the control
circuit for the clamping and perforating mechanism 50 after a
predetermined length of tape has passed around the pulley 57 As best
shown in Fig 3, the pulley 57 is secured to a shaft 66 which is
journaled in bearings 67 and 68 secured to a bracket 69.
The shaft 66 is coupled to the input shaft of the variable speed drive
58 by a flexible coupling 70 By varying the speed ratio of the
variable speed drive 58, variations in the length of tape passing
around the pulley 57 between actuations of the control switch by the
cam 65 can be obtained.
Guide roller 61, guide roller 63 and guide plate 64 are secured to a
plate 71 which in turn is secured to a slide 72 (Figs I and 3).
Slide 72 is slidably mounted on a plate bracket 73 by bolts 74 which
extend -through slots in the slide 72 Adjustment of the slide 72 is
provided by means of a screw-threaded shaft 75 journaled in a plate 76
secured to bracket 73 and screwed into a block 77 secured to the slide
72 Adjustment of slide 72 by rotation of shaft 75 by means of a hand