Note: Descriptions are shown in the official language in which they were submitted.
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ELECTRICAL TERMINAL CRIMPING ~PPARATUS
This invention relates to electrical terminal crimping
apparatus by means of which an electrical terminal is secured to a
stripped end oi' a length o~ ~lexible insulated conductor (hereinafter,
~or convenience, referred to as an electrical lead) by a crimping
operation.
In a known kind o~ electrical terminal crimping apparatus
a strip oi' electrical terminals comprising a plurality of terminals
linked end-to-end is fed automatically through the apparatus and,
each time the apparatus is actuated by an operator, the leading
terminal of the strip is simultaneously severed from the strip and
crimped to a stripped end o~ an electrical lead positioned by the
operator in the crimping station between crimping dies of the
apparatus. To achieve a high rate oi production oi' terminated
electrical lea~s, a high degree of dexterity is required by the
operator. Usually, the operator holds a bunch of electrical leads
in one hand and, for each electrical lead in turn, the operator with-
draws one electrical lead from the bunch, positions a stripped end
of the lead in the crimping station between the crimping dies oi the
apparatus, actuates the crimping apparatus to cause it simultaneously
to sever the leading terminal from the strip and to crimp it to the
stripped end o~ the lead, and then moves the terminated end oi' the
lead ~rom between the crimping dies before positioning in the crimping
station between the dies another electrical lead irom the bunch.
Manipulation of an electrical lead by the operator occupies a major
proportion o~ the complete time cycle o~ securing an electrical
terminal to the lead. For example, although a known ~orm of electrical
terminal crimping apparatus is capable of 13,500 crimping operations
per hour, when electrical leads are ~ed in turn to the apparatus by
an operator the number of electrical leads terminated by the apparatus
per hour seldom exceeds 2000; that is to say, the apparatus is
operating at only approximately 15~ of its optimum rate. The r'~
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~ terity of an operator in manipulating electrical leads is therefore
a major factor in the efficiency of the terminating operation.
Where safety regulations require the provision of a guard
around the crimping dies of the apparatus, the situation is
aggravated because, in this case, in order to introduce a stripped
end oi an electrical lead in the crimping station between- crimping
dies, the operator has first to insert the lead through an aperture in
the guard and, in order to move a terminated lead from between the
crimping dies, the operator has to guide the terminated lead from the
aperture along a slot in the guard. Thus, where a guard is employed,
manipulation of electrical leads during the complete terminating
cycle is more difficult and the éfficiency of the terminating operation
is inevitably further reduced.
We have found that a major proportion of the time employed
in manipulating an electrical lead during a terminating cycle is
taken in moving a terminated lead from between the crimping dies to a
sufficient extent to permit another lead to be positioned in the
crimping station between the dies because it is difficult for an
operator to move the terminated lead from between the dies and
position another lead between the dies at one and the same time.
It is an ob~ect o$ the present invention to provide, for
use in crimping an electrical terminal to a stripped end of an
electrical lead, improved electrical terminal crimping apparatus of
the kind in which a strip of terminals comprising a plurality of
terminals linked end-to-end is fed to the crimping station, which
apparatus can be operated more efficiently than crimping apparatus
hitherto proposed.
According to the present invention, the improved apparatus
comprises at least two crimping dies defining a crimping station and
so mounted that at least one o~ the dies is constrained to move towards
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and away from the other die, wherein the movable die or at least one of the
movable dies has operatively connected to the die, a reciprocating pushing
device which is constrained to move in a substantially rectilinear path towards
and away from the crimping station and which is adapted to push a terminated
electrical lead from between the dies in a direction lateral to the direction
of feed of the terminals, the arrangement being such that, as said movable die
travels away from the other die after an electrical terminal has been crimped
to a stripped end of an electrical lead, said pushing device is automatically
actuated to move along said rectilinear path towards the crimping station and
to push the terminated electrical lead laterally from between the dies to a
sufficient extent to permit the stripped end of another lead to be positioned
between the dies.
The reciprocating pushing device may be so operatively connected to
the movable die that, after a terminated electrical lead has been pushed later-
ally from between the dies by the pushing device, the pushing device is automa-
tically actuated to move along said rectilinear path in the opposite direction
away from the crimping station but when, as is preferred, the electrical terminal
crimping apparatus includes, at the crimping station and spaced from the fixed
die, a backplate for limiting the extent to which a stripped end of an electrical
lead can be introduced between the crimping dies, preferably the pushing device
is so operatively connected to the movable die that, after pushing a terminated
electrical lead laterally from between the crimping dies, it remains in the
crimping station until the crimping apparatus is re-actuated and the movable
die starts to move towards the fixed die to effect the crimping operation. By
so doing, the pushing device serves the dual role as a guard which substantially
reduces the risk of a stripped end of an electrical lead being introduced under
the backplate and too far into the crimping station and as a table on which a
stripped end of an electrical lead can be positioned as it is introduced against
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the backplate.
Where the electrical terminal crimping apparatus is of such a form
that the leading terminal of a strip of electrical terminals linked end-to-end
is fed to the crimping station as the movable die moves towards the fixed die,
the part of the reciprocating pushing device that will temporarily occupy the
crimping station after it has pushed a terminated electrical lead laterally
from between the dies may be of any convenient shape and size, but where the
electrical terminal crimping apparatus is of such a form that the leading term-
inal of a strip of electrical terminals linked end-to-end is fed to the crimping
station as the movable die moves away from the fixed die and it is desired that
said part of the pushing device remain in the crimping station until the crimp-
ing apparatus is re actuated, said part of the pushing device must be of such a
shape and size that the leading terminal of the strip can be fed under said
part of the pushing device on to the fixed die.
The reciprocating pushing device may be operatively connected to the
movable die by any convenient means but perferably it is operatively connected
to the movable die by a linkage mechanism of such a form that, as the movable
die moves away from the other die, the pushing device is caused to move along
said rectilinear path towards the crimping station and, as the movable die moves
towards the other die, the pushing device is caused to move along said rectili-
near path in the opposite direction away from the crimping station. In this
case conveniently the reciprocating pushing device may be a substantially rigid
elongate member arranged in axial alignment in said rectilinear path and having,
at its leading end, a head of a shape and size suitable for engaging a terminated
electrical lead to push it laterally from between the dies and for serving as a
guard and support table during introduction of a stripped end of an electrical
lead into the crimping station.
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6~
Preferably, the linkage mechanism operatively connecting a substan-
tially rigid elongate member constituting the reciprocating pushing device to
the m~vable die comprises a crank arm which, at or near one of its ends, is
pivotally mounted on the body of the crimping apparatus adjacent the movable
die and, at or near the other of its ends, is in slidable engagement with the
elongate pushing device which is urged to move along said rectilinear path
towards the crimping station by at least one associated spring, the arrangement
being such that, as the movable die travels towards the other die to effect the
crimping operation, the movable die engages the crank arm and causes it to
pivot in such a direction as to move the elongate pushing device away from the
crimping station against the action of its associated spring or springs and,
after the movable die has travelled a predetermined distance from the other die,
the movable die permits the elongate pushing device to move along said recti-
linear path under the action of its associated spring or springs to push a
terminated electrical lead laterally from the crimping station. In a preferred
arrangement, a freely rotatable roller is mounted on the movable die in such a
position as to roll along a surface of the crank arm as the movable die travels
towards and away from the other die.
In one alternative embodiment, the reciprocating pushing device may
be constituted by a fluid-operated piston working in a cylinder and arranged to
lie along said rectilinear path, the arrangement being such that, injection of
fluid into the rear of the cylinder to cause the piston to move to its forward
position and push a terminated lead from between the crimping dies, is under the
control of a valve actuated by a cam mounted on the drive spindle of the crimp-
ing apparatus. The piston may be so spring loaded that, when injection of
fluid into the cylinder ceases, the piston returns to its retracted position
under the action of the spring or the piston may be caused to return to its
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retracted position by transferring injection of fluid from the rear end of the
cylinder to the forward end of the cylinder; in both cases, injection of fluid
will be under the control of the cam-actuated valve.
A foot switch may be provided for actuation of the crimping apparatus
by an operator but, preferably, when the crimping apparatus includes a backplate,
the backplate is made of electrically conductive metal or metal alloy, or has
an electric contact extending therethrough, and has a resilient contact mounted
on the front face of but electrically insulated from the backplate or electric
contact, the arrangement being such that, as a stripped end of an electrical
lead is introduced into the crimping station and abuts the resilient contact,
the resilient contact is urged against the backplate or electric contact to
complete a control circuit which effects actuation of the crimping apparatus.
The use, in electrical terminal crimping apparatus of the kind in
which a strip of terminals linked end-to-end is fed to the crimping station, of
a pushing device as hereinbefore described for pushing a terminated electrical
lead from between the crimping dies substantially simplifies the manipulative
operations to be carried out by an operator when successively feeding electrical
leads to the apparatus with the result that the number of electrical leads that
can be terminated by the apparatus per hour can be doubled or even trebled.
The receiprocating pushing device as hereinbefore described is inex-
pensive and simple to manufacture and can be incorporated in known forms of
electrical terminal crimping apparatus of the aforesaid kind at low cost.
The invention is further illustrated by a description, by way of
example, of two forms of electrical terminal crimping apparatus with reference
to the accompanying drawings, in which:
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Figure 1 is a front elevation of the first form of
electrical terminal crimping apparatus with the pushing device
positioned in the crimping station;
Figure 2 is a side view of the apparatus as shown in
Figure 1;
Figure 3 is a front elevation of the first form of
electrical terminal crimping apparatus with the pushing device in
the withdrawn position;
Figures 4 and 5, respectively, are fragmental front
and plan views of the backplate and resilient contact switch of the
apparatus shown in Figures 1 to 3;
Figure 6 is a front e1evation,~f_~he second form of
electrical terminal crimping apparatus, and
.
Figure 7 is a sectional view taken on the line VII-VII
in Figure 6.
.
Each crimping apparatus shown in Figures 1 to 5, and 6
and 7 comprises a i'ixed die 1 and, mounted above the fixed die and
constrained to move towards and away irom the fixed die on actuation
of the crimp1ng apparatus, a movable die 2 carrying crimping blades
6 'and 7 and a cutting blade 8. In both apparatus, a strip of terminals
comprising a plurality of terminals linked end-to-end is fed automatically
to the crimping station defined by the fixed and movable dies 1 and 2.
:
In the i'irst form oi' crimping apparatus shown in Figures
1 to 5, an elongate pushing arm 10, which near its leading end is stepped
- to form a head 11, is constrained to reciprocate in a substantially
rectilinear path which is substantially normal to the direction o~
movement of the movable die 2. The pushing arm 10 is urged towards
the crimping station along the rectilinear path by a coil spring 12.
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votally mounted on the body of the crimping apparatus adjacent
the movable die 2 is a crank arm 14 which, at its lowermost end,
engages in a slot 15 in the pushing arm 10 and abuts a pin 16 extending
across the slot. A ~reely rotatable roller 17 is mounted on the movable
die 2 in such a position that, as the movable die travels towards or
away from the ~ixed die 1, the roller rolls along a surface of the
crank arm 14. - -
Fixedly mounted above and spaced from the iixed die 1
in such a position as to limit the extent to which a stripped end of
an electrical lead can be introduced between the crimping dies and to
permit the leading terminal of a strip of terminals to be fed on to
the iixed die in the crimping station is a backplate 19 through which
protrudes an electrically conductive contact stud 21 which is
insulated ~rom the backplate by a bushing 20 o~ insulating material.
Mounted on the iront ~ace o~ the backplate 19 is a spring-contact 22
which, when urged against the contact stud 21 by a stripped end oi
an electrical lead when introduced into the crimping station, completes
a control circuit which e~ects actuation oi the crimping apparatus.
To ~acilitate correct positioning o~ a stripped end of an electrical
lead in the crimping station, a guard 23 mounted on the backplate 19
in ~ront o~ the spring contact 22 has an aperture 24 which is in
alignment with the fixed die 1 in the crimping station and into
which the stripped end oi' an electrical lead must be inserted in order
to engage the spring contact and ef~ect actuation o~ the control
circuit. It will be appreciated that ii' the stripped end o~ an
electrical lead is not correctly positioned in the crimping station,
the guard 23 will prevent actuation of the control circuit.
With the movable die 2 in the raised position and the
head 11 of the pushing arm 10 in the crimping station as shown in
Figures 1 and 2, when a stripped end o~ an electrical lead is introduced
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to the crimping station between the head and the movable die and is
inserted through the aperture 24 in the guard 23 to abut the
spring contact 22 and urge it into contac-~ with the contact stud 21
to close the control circuit and e~fect actuation of the crimping
apparatus, the movable die moves downwards towards the fixed die 1
so that the roller 17 rolls along a sur~ace of the crank arm 14 and
causes it to pivot in a clockwise direction. As the crank arm 14
pivots, the lowermost end of the crank arm slides along the slot 15,
abuts the pin 16 and urges the pushing arm 10 away from the crimping
station along the rectilinear path against the action o~ the coil
spring 12 until the arm reaches the position shown in Figure 3. At
the same time, the leading terminal of a strip of terminals linked end-to-
end is automatically ~ed on to the ~ixed die 1 and, as the movable die 2
continues its downward movement, the movable die gathers the
stripped end o~ the electrical lead within the vee o~ the crimping
blades 6 and 7, positions it in the leading terminal on the ~ixed die
and e~ects the crimping operation; the cutting blade 8 also cuts
the leading terminal ~rom the strip o~ terminals. A~ter the crimping
and cutting operation has been e~ected, the movable die 2 starts
to move upwardly away from the ~ixed die 1. If, as the movable die 2
moves it carries in the veè o~ the crimping blades 6 and 7 the
terminated end o~ the electrical lead, the terminated end will abut
the undersur~ace o~ the backplate 19 which will serve to e~ect the
terminating lead so that it drops back on the fixed die 1. As the
movable die 2 continues to move upwardly, the roller 17 rolls along
a surface o~ the crank arm 14 and e~fectively holds the pushing arm
10 against the action of ~ts coil spring 12 until the movable die
has moved upwardly a su~icient distance to permit the pushing arm
to move into the crimping station. When the movable die 2 is clear
o~ the crimping station, the pushing arm 10 is urged along the
rectilinear path under the action o~ the coil spring 12 to cause the
crank arm 14 to pivot in an anti-clockwise direction and to push the
terminated lead laterally from the crimping station. The crimping station
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now free to receive a stripped end of another electrical lead. ~;
In the crimping apparatus shown in Figures 6 and 7, a
backplate 30 of electrically conductive metal is fixedly mounted
above and spaced from the fixed die 1 in such a position as to limit
the extent to which a stripped end of an electrical lead can be
introduced between the crimping dies and to permit the leading
terminal T o~ the strip o~ terminals to be fed under the backplate
and on to the fixed die in the crimping station. Mounted on the
front face oi' and electrically insulated from the backplate 30 is
a spring contact 31 which, when urged against the front face of the
backplate by a stripped end of an electrical lead, completes a
control circuit which effects actuation of thé crimping apparatus.
Mounted alongside the crimping station is a pneumatic
cylinder 32 in which works a piston 33 which has at its ~ree end a
head 34 and which constitutes the pushing device ~or pushing a
terminated lead laterally irom between the crimping dies. The
piston 33 is spring loaded and is constrained to reciprocate in a
substantially rectilinear path, which is substantially normal to
the direction o~ movement o~ the movable die, under the control
of a valve (not shown) connected in ihe air supply to the rear end
o~ the cylinder 32 and operated by a cam mounted on the drive sha~t
o~ the crimping apparatus.
Positioned around the crimping station is a guard 34
o~ transparent plastics material having a substantially vertical
slot 35 for introduction of,a stripped end of an electrical lead
between the dies and a substantially horizontal slot 36 having a
funnel-shaped opening 37 ~or accommodating lateral movement of a
terminated electrical lead.
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~ igures 6 and 7 show the state of the crimping apparatus
at the start of a crimping cycle with the piston 33 in its forward
position and with the head 34 positioned in the crimping station and
serving as a guard and support table for a stripped end of an
electrical lead to be inserted between the crimping dies. When a
stripped end of an electrical lead L is inserted through the vertical
slot 35 and against the spring contact 31 to urge it into contact
with the backplate 30 to close the control eircuit and effect
actuation oi' the crimping apparatus, the movable die 2 moves down-
wardly towards the ~ixed die 1 and the cam on the crankshaft of the
crimping apparatus closes the valve to stop the supply of
air to the rear of the cylinder 32 and so permit the piston 33 to move
to its retracted position under the action of the spring. The leading
terminal T of a strip oi' terminals linked end-to-end is automatically
~ed on to the i'ixed die 1 and, as the movable die 2 continues its
downward movement, it gathers the stripped end of the electrical lead L
within the vee of the crimping blades, positions it in the leading
terminal and e~fects the crimping operation. After the crimping operation
has been ei'fected, the movable die 2 starts to move upwardly away from
the fixed die 1 If, as the movable die 2 rises it carries in the vee
of the crimping blades 6 and 7 the terminated end of the electrical lead,
the terminated lead will abut the undersurface of the backplate 30
which will serve to e~ect the terminated lead so that it drops back on
the fixed die 1. As the movable die 2 continues to rise, the cam on
the crankshaft of the crimping apparatus opens the valve to cause
air under pressure to be fed to the rear o~ the cylinder 32 and so
drive the piston 33 towards its ~orward position, the head 34 of
the piston pushing the terminated lead laterally from between the
crimping blades and along the slot 36. The crimping station is now
free to receive a stripped end o~ another electrical lead.
