Note: Descriptions are shown in the official language in which they were submitted.
L216~'70
Electrical Lead Transfer Apparatus
Electrical leads for use with man~ kin~s
of electrical apparatus each comprise a predetermined
length of flexible insulated conductor to at least
one end of which an electrical termination is secured.
In the manufacture of such electrical leads a flexible
electrically insulated conductor is fed to a first
machine (hereinafter referred to.as a measuring and
cutting machine) which measures a predetermined length
of the insulated conductor and cuts the insulated
conductor to said predetermined length. Another
machine or other machines is or are employed to secure
an electrical termination to a stripped end of each of
said predetermined lengths of insulated conductor to
form an electrical lead and, in some instances, to apply
a preformed housing of electrically insulating material
to the or each electrical termination of each electrical
lead.
To facilitate a high rate of production of
such electrical leads, it is the practice to mount
these machines alongside one another with their oycles
of operation synchronised and to employ apparatus which
automatically transfers each eut predetermined length
of insulated conductor in turn from the measuring and
cutting machine to the other machine or to each of the
other machines in succession, such automatic transfer
apparatus hereina~ter, for convenience, being referred to as
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"electrical lead transfer apparatus". Electrical lead
transfer apparatus that have hither-to been proposed and used
are complicated and expensive and it is an object of the
presen-t invention to provide improved electrical lead
transfer apparatus which is simple in design and inexpensive
to manufacture.
According to the invention we provide, for use with a
measuring and cutting machine and other machine or machines
for effecting an operation on a predetermined length of
insulated conductor, electrical lead transfer apparatus
comprising a flexi~le conveyor consisting of a length of coil
spring of resilient material arranged in an endless loop, the
coils of the spring constituting a multiplicity of
transversely extending resilient parts between any adjacent
pair of which a predetermined length of insulated conductor
can be resiliently gripped and the coil spring being
constrained to travel in the direction of its length from the
measuring and cutting machine to the other machine or
machines; a device coupled to the measuring and cutting
machine for inserting a cut predetermined length of insulated
conductor between an adjacent pair of coils of the spring so
that the length of insulated conductor is gripped
therebetween; means for causing the coil spring to ~ravel
intermittently a limited distance in the direction of its
length; and, dow:nstream of said other machine or of the last
of said other machines, means for ejecting a predetermined
length of insulated conductor from between an adjacent pair
of coils of the spring.
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Since a length of coil spring is highly flexible in all
directions radial to the longi-tudinal axis of the spring, the
use of a length of coil spring as the flexible conveyor has
the important advantage -that the positioning of the or each
machine relative to the measuring and cutting machine is not
critical and, in travelling between the measuring and cutting
machine and the last machine, the length of coil spring may
travel in more than one rectilinear or curvilinear direction
and need not be constrained to travel in a single plane.
Another advantage arising from the use of a length of coil
spring as the flexible conveyor is that, at any operating
station, by appropriate deflection of the part of the coil
spring carrying a predetermined length of insulated
conductor, an end of the conductor can be introduced into
the bore of a tubular terminal or a terminated end of the
conductor can be introduced into a bore of an insulating
housing.
The measuring and cutting machine may also strip the
insulation from each predetermined length of insulated conductor
at one or each of its ends, or the first of said other machines may
be a machine for this purpose. The other machine or the second of
the other machines (hereinafter referred to as a terminating
machine) is employed to secure an electrical termination to a
stripped end of each cut predetermined length of insulated conductor
to form an electrical lead. In some circumstances, the last of said
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other machines may be a machine for applying a preformed
housing of electrically insulating material to a terminated
end of an electrical lead or for inserting a terminated end
of an electrical lead into a preformed housing of
electrically insulating material.
~ here the measuring and cutting machine includes a
cutting head which moves towards or away from a length of
insulated conductor when fed through the machine, the device
for inserting a cut predetermined length of insulated
conductor between adjacent coils of the coil spring or
between adjacent transversely extending resilient parts of
another flexible conveyor preferably is directly or
indirectly carried by the cutting head and is of such a form
that, as the cutting head completes its movement towards the
length of insulated conductor being fed to the measuring and
cutting machine and cuts a predetermined length of insulated
conductor, the device inserts the cut length, or causes the
cut length to be inserted, between said adjacent coils or
other transversely extending resilient parts to be gripped
therebetween. In its simplest form, the conductor-insertion
device may be a bifurcated finger which straddles the length
of coil spring or othar flexible conveyor and pushes the cut
predetermined length of insulated conductor between a pair of
adjacent coils or other transversely extending resilient
parts.
Where the measuring and cutting machine also strips
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the insulation at one or each end of a cut length of insu-
lated conductor and such stripping operation is effected by
moving the cut length of insulated conductor in the direction
of its length with respect to the cutting head, preferably
the conductor-insertion device is operatively coupled to
the cutting head and is of such a form that, as the cutting
head effects the cutting operation, the device first lightly
grips the cut length of insulated conductor to permit
relative lengthwise movement between the gripping device and
the length of insulated conductor during the stripping
operation, the device then tightly grips the length of
insulated conductor as the device effects the operation of
inserting the cut length of insulated conductor between a pair
of adjacent coils or other transversely extending resilient
parts and and, after the length of insulated conductor has
been inserted between adjacent coils or other resilient parts,
the device releases its grip on the length of insulated
conductor. In this case, the device may be operatively
coupled to the movable cutting head by mechanical means, but,
preferably, the device is fluid-operated under the control
of the movable cutting head.
Any suitable means for causing the length of coil
spring to travel a limited distance in the direction of its
length after insertion of each successive cut length of insu-
lated conductor may be employed but, where it is desired to
cause the length of coil spring to travei in the same direction
as the cutting head when effecting the cutting operation,
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preferably a spring-loaded pawl is directly or indirectly
carried by the cutting head in such a way that, as the
cutting head moves in such a direction as to effect the
cutting operation, the pawl engages a coil of the length
of coil spring and moves the coil spring a limited distance
in the direction of its length until another adjacent pair
of coil springs underlies the length of insulated conductor
being fed to the measuring and cu-tting machine and, as the cutting
head moves in the opposite direction after cutting a
predetermined length of i~sulated conductor, the pawl trips
over the coils of the length of coil spring.
The means for ejecting each electrical lead
from between adjacent coils of the length of coil spring may
take any convenient form but, preferably, it comprises a
pulley wheel around which the length of coil spring is
constrained to travel and which has a flange or flanges of
such depth that, as the length of coil spring with electrical
leads gripped between spaced adjacent coils of the coil
spring travels partway around the pulley wheel, the or each
flange pushes each electrical lead in turn out of the length
of coil spring.
Operation of the other machine or each of the other
machines to which the length of coil spring or other flexible
conveyor conveys cut lengths of insulated conductor for a
terminating or other operation, may be controlled by a
microswitch which is actuated by the length of coil spring
or other flexible conveyor or by a length of insulated conductor
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carried by the coil spring when the coll spring or other
flexible conveyor is stationary and the conductor is
positioned in the terminating or other operating station
of the machine. Preferably, the cycles of operation of the
measuring and cutting machine and of the other machine or
machines are so synchronised that the operations of measuring,
cutting and stripping an end or ends of a length of insulated
conductor, inserting the cut length of insulated conductor
between adjacent coils of the length of coil spring or between
adjacent transversely extending resilient parts of another
flexible conveyor, terminating an end of a length of insulated
conductor, and applying a preformed housing of insulating
material to a terminated end of a length of insulated conductor
are effected concùrrently under a single overall control.
~ hen it is desired to strip the insulation from and
to terminate each end of a cut predetermined length of insu-
lated conductor, two electrical lead transfer apparatus as
hereinbefore described may be employed, one associated with
the leading end of a cut predetermined length of insulated
conductor in the measuring and cutting machine and the other
associated with the trailing end of said cut length of insu-
lated conductor in the machine, the coil springs or other
flexible conveyors being arranged to travel alongside but
spaced from one another with end parts of each cut length of
insulated conductor being gripped by adjacent coils of the two
coil springs or adjacent transversely extending resilient parts
of the two other flexible conveyors. In this case, movement
of the coil springs or other flexible conveyors and operation
of the other machine or machines of each electrical lead
transfer apparatus are synchronised so that the terminating
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and other operations on the ends of each cut length of
insulated conductor are effected concurrently. Although the
two lengths of coil spring or other flexible conveyor may be
arranged to extend substantially parallel to one another,
preferably they are arranged to converge towards their
downstream ends so that there is substantially no risk that
a length of insulated conductor gripped by the two springs
or other flexible conveyors will be subjected to such a tension
that it will be caused to move transversely with respect to
the coil springs or other flexible conveyors and will not be
correctly positioned in the terminating or other operating
station. In this latter case, preferably one coil spring has
a left hand lay and one coil spring has a right hand lay and they
are so arranged that the coils of each coil spring lie
substantially parallel to the direction in which a length of
insulated conductor is fed to the measuring and cutting machine.
The invention will be further illustrated by
a description, by way of example, of the preferred form of
electrical lead transfer apparatus and of modified forms
of the transfer apparatus with reference to the accompanying
diagrammatic drawings, in which:-
Figure 1 is a schematic lay-out of the preformed
form of electrical lead transfer apparatus;
~ igures 2 and 3, respectively, are front and top
views of the device, in the apparatus shown in Figure 1,
for inserting a cut predetermined length of insulated con-
ductor between adjacent coils of the length of coil spring;
Figure 4 is a front view of an alternative device
for inserting a cut predetermined length of insulated con-
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ductor bekween ad~acent coils o~ a length of coil spring,
and
Figure 5 is a schematic lay-out of an alternative
form of electrical lead transfer apparatus.
Referring to Figure l, electrical lead pro-
cessing apparatus comprises a measuring, cutting and
stripping machine 21, _ a term-
inating machine 31, an insulating machine 41 ~or appl~Jing
preformed housings of electrically insulating material to
the terminated ends of electrical leadsandg for transferring
cut predetermined lengths of insulated conductor in succession
from the measuring, cutting and stripping machine to the
terminating machine and from t'ne terminating machine to the
i~sulating machine, the preferred form of electrical lead
transfer apparatus 1.
The measuring, cutting and stripping machine 21
includes a shaft 22 of substantially square cross section
alonG which a block 23 carr~ing clamping jaws 24 can be
caused to reciprocate and, at a cutting and stripping station
25, two opposed heads 26 on which are carried three diametri-
cally opposed pairs of cutters 27. In each cycle of oper-
ation of this known machine the jaws 24 of the block 23
clamp onto the leading end of electricall~ insulated con-
ductor C being fed to the machine ard pull the insulated
conductor through the machine until a predetermined length
o~ insulated conductor extends between the block and the
cutting and stripping station 25. The three cutters 27
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then cut the insulated conductor at each of three
longitudinally spaced positions. The central pair o~
cutters sever the insulated conductor to form an
electrical lead whose leading end is held in the clamping
jaws 24; each of the other pairs of cutters cuts through
the electrical insulation but not through the conductor
itself, the short length of severed insulation on each
side of the central cut being subsequentl~ stripped from
the conductor by appropriate movement of the block 23.
The clamping jaws then release the electrical lead and
move back to grip the leading end of the insulated con-
ductor at the cutting and stripping station 25. Operation
of the reciprocating block 23 and clamping jaws 24 and the
cutting and stripping mechanism is controlled by the motor
driven shaft 22 in a manner not material to the present
invention. If the predetermined length of insulated con-
ductor required cannot be obtained by a single stroke of
the block ~3, the block and ~aws 24 can be caused to reciprocate
several times until the required length is obtained when the
cutter blades 27, whose operation has been overridden during
reciprocation of the block, are brought into operation.
The terminating machine 31 has a main shaft 32 on
which is carried a pair of crimping blades (not shown) which,
on the down stroke~ crimp an electric termination being fed
to the machine on to a strippe~ end of an electrical lead
positioned at the terminating station 33~ the crimpe~
termination being released from the crimping blades on the
first part of the up stroke.
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The insulating machine 41 has a reciprocating
finger 42 which intermittently pushes the leading pre-
formed housing of a chain of preformed housings linked
end-to-end (not shown) on to a terminated end of an
electrical lead positioned at the insulating station 43.
The electrical lead transfer apparatus 1
comprises a length 2 of coil spring in the form of an
endless loop which is constrained to travel in the direc-
tion of its length around spaced pulley wheels 3 and 4,
the pulley wheel 3 being on the side of the measuring,
cutting and stripping machine 21 remote from the terminating
machine 31 and the pulley wheel 4 being on the side of t`ne
insulating machine 41 remote from the terminating macnine 31.
As will be seen and for a reason that will be explained, the
axes of the pulley wheels 3 and 4 are so inclined that the
part of the coil spring 2 returning from the pulley wheel 4
to the pulley wheel 3 is not immediately below the part of the
coil spring travelling from the pulley wheel 3 to the pulley
wheel 4. Operatively coupled to one of the heads 26 is a
device ~ for inserting a cut predetermined length of insulated
conductor between ad~acent coils of the coil spring 2, and
a spring -loaded pawl 6 for causing the coil
spring to travel a limited distance in a direction towards
the terminating machine 31. Associated with the terminating
machine 31 is a microswitch 34 which~ when actuated by a
cut predetermined :Length of insulated conductor positioned
at the terminating sta~ion 33, effects operation of the
terminating machine. Likewise, associated with the insu-
latingmachine 41 is a microswitch 44 which, when actuated
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by a cut predetermined length of insulated conductor
positioned at the insulating station 43, effects
operation of the reciprocating finger 42 to appl~ a
preformed insulating housing to the terminated end of
the length of insulated conductor. The rim of the
pulley wheel 4 is bounded by a pair of flanges 7 of
such a depth that, as a part of the coil spring 2
carrying an electrical lead passes around the pulley
wheel, the flanges push the electrical lead from between
adjacent coils of the coil spring.
~ s will be seen on referring to Figures 2
and 3, the device 5 for inserting a cut predetermined
lengt~n 50 of insulated conductor between ad~acent coils
of the length 2 of coil spring comprises a bifurcated
resilient gripper 51 which is mounted on a pneumatically
operated piston 52 working in a c~linder 53 positioned
below the insulated conductor C being fed between the heads
26 of the machine 21. Each finger of the bifurcated
resilient gripper 51 is slotted to receive a cut length
of insulated conductor, the conductor-receiving slots
54 being off-set so that a length of conductor gripped
by the gripper lies substantially parallel to the under-
lying adjacent coils of the length 2 of coil spring
between which it is to be inserted. Alternatively, the
length 2 of coil spring can be constrained to move in
a direction such that the coils of the length of coil
spring between which a cut length of insulated conductor
is to be inserted lie substantially parallel to the
direction in which insulated conductor C is fed to the
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machine 21.
The reciprocating motion of the piston 52
is under tne control of a changeover valve 28 which,
in one position feeds air under pressure to the rear
end of the cylinder 5~ and, in the other of its two
positions, feeds air under pressure to the forward end
of the cylinder. The changeover valve 28 is actuated
and de-actuatsd by one of the ~eads 26 carrying the
cutters 27.
In operation, as the heads 26 move inwardly to
cause the cutters 27 to cut a predetermined length of
insulated conductor C, the changeover value 28 is de-
actuated and air is fed to the rear of the cylinder 53
to cause the piston to move to its forward position in
which position, as shown in Figure 2, the gripper 51
lightly grips the cut predetermined length 50 of insu-
lated conductor. Stripping of the insulation from the
cut ends of the insulated conductor is then effected, the
light grip of the gripper 51 being such that the cut length
50 can move lengthwise with respect to the gripper. As
the :~eads 26 then move away from one another, the changeover
valve 28 is actuated to ~e~d air to the forward end of the
cylinder 53 to cause the piston 52 to withdraw to its re-
tracted position. As the piston 52 retracts, the gripper
51 is carried downwardly towards the length 2 of coil spring
passing b~tween the fingers of the bifurcated gripper and passes
through an aperture 56. The side faces of the gripper 51
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have cam surfaces 55 which engage the boundary surfaces
of the aperture 56 to cause the gripper 51 to grip the cut
length 50 of insulated conductor tightly as it is inserted
between ad~acent coils of the length 2 of coil spring.
As the gripper 51 emerges from the aperture 56,the
grip on the cut length of insulated conductor is released
and) after another length of insulated conductor has been
measured by the measuring, cutting and stripping machine
21 and as the heads 26 move to cause the cutters 27 to
cut itJ the spring-loaded pawl 6 engages the length 2 of
coil spring and causes it to move a limited distance towards
the terminating machine 31 and the changeover valv~ 28 is de-
actuated to cause air to be fed to the rear of the cylinder
5~ to drive the piston 52 forward and cause the gripper 51
to grip lightly the next cut length of insulated conductor.
This sequence of operations is rep&ated for each measured
and cut length of insulated conductor.
Figure 4 shows an alternative device 5 for inserting
cut lengths of insulated conductor between adjacent coils of
a length 2 of coil spring, parts that are similar to those
of the device shown in Figures 2 and 3 being given the same
reference. In the device shown in Figure 4, the bifurcated
resilient gripper 51 is carried by a member 61 coupled to
two levers 63 o~ a toggle mechanism 62 whose other levers
64 are secured to the heads 26 of the machine 21. The
arrangement is such that as the heads 26 move towards one
another to cause the cutters 27 to~cut a length of t'ne
insulated conductor C~ the toggle mechanism 62 raises the
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gripper 51 to cause it to grip lightly the cut length of
insulated conductor. After stripping of the cut ends
of insulated conductor, the heads 26 move apart and the
toggle mechanism 62 mOrJes the gripper 51 downwardly through
the aperture 56, the cam surfaces 55 operating as previously
described.
The alternative electrical lead transfer appa-
ratus shown in Figure 5 is employed with electrical
processing apparatus comprising a meQsuring and cutting
machine.l21, associated with which are two stripping
machines 122, two terminating machines 131 and two insu-
lating machines 141. One stripping machine 122, one
terminating machine 131 and one insulating machine 141 are
associated with the leading end of a measured and cut length
of insulated conductor and one stripping machine, one termi-
nating machine and one insulating machine are associated withthe trailing end of a measured and cut length of insulated
conductor. Each s~et of stripping, terminating and insulating
machines has an associated transfer apparatus 101.
Each transfer apparatus 101 comprises a length 102
of coil spring arranged in the form of a closed loop and
constrained to move at intervals around a pair of spaced
pulleys (not shown) by a spring loaded pa~l (not shown)
similar to that described with reference to Figure 1.
Operatively coupled to the cutting heads 126 of the measur-
ing and cutting machine 121 are two bifurcated fingers 10~,
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one included in each transfer apparatus, which serve
to push one end of a cut length of insulated conductor
bet~veen adjacent coils of the associated coil spring
102 as the cutting heads move to effect cutting of the
insulated conductor being fed through the machine 121.
At each stripping machine 122, when an end of a cut length
of insulated conductor carried by the coil spring is
positioned in the stripping station 123, a pushing
device 124 actuated by a microswitch 125 serves to
push the coil spring away from the stripping machine so
that the cut insulation is stripped from the end of the
insulated conductor. The terminating and insulating
machines 131 and 1~1 operate as described with reference to
Figure 1. Operation of the machines and movement of the
coil spring of both transfer apparatus are synchronised so
that the ends of each cut predetermined length of insulated
conductor are terminated and insulated concurrently.
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