GB2257066A - Insulation severing and stripping unit - Google Patents

Abstract

As shown in Figures 7 and 8, an insulation severing and stripping unit (12) has a pair of insulation severing jaws (24). Each jaw (24) comprises a pair of mild stool blade supports (158', 159) between which is sandwiched an insulation severing blade (160) made from a hardened steel. Each blade support (158', 159) has a wire receiving notch (166, 167) aligned with a similar such notch (166, 167) in the other blade support (158', 159) and with a wire receiving notch (166', 1679 in the severing blade (160). The notches (166', 167') in the blade (160) are of smaller radius than the notches (166, 167) in the blade supports (158', 159). <IMAGE>

Description

INSULATION SEVERING AND STRIPPING UNIT This invention relates to a unit for severing the insulation at an end portion of an insulated electrical wire and stripping the severed portion of the insulation from the wire end portion.

There is described and claimed in Patent Application NO 8914500.7 from which the present Application has been divided, apparatus for stripping the insulation from an end portion of an insulated electrical wire, withdrawing an electrìt;al terminal from a carrier tape therefor, and crimping the terminal to the stripped end portion of the wire, comprising a wire gripper first unit, an insulation severing and stripping second unit, a terminal prefeed third unit, a pair of terminal gripping and terminal crimping heads and a carrier tape conveyor, the second unit being moveable back and forth along a path of movement, between an advanced position proximate to the first unit, to receive and sever the insulation of, the end portion of an insulated wire gripped by the first unit, and a retracted position remote from the first unit to strip the insulation from said end portion, said heads being moveable between an open position in which they are clear of said path and a closed, terminal gripping position intersecting said path, the third unit being actuable partially to withdraw said terminal from said tape for positioning by said tape conveyor between said heads in the open position thereof and in the retracted position of the fitst unit, so that said heads grip the terminal when moved to their closed position, said heads being moveable in that position towards the first unit fully to withdraw the terminal from the tape and to insert the stripped wire end portion into the terminal and being then ac:uasle to crimp the terminal to the stripped wire end portion.

Thus upon the terminal gripping and terminal crimping heads being returned to their open position, zsnd the gripper unit being actuated to release the wire, no sensible tension need be applied by the operator to the wire in order to remove the wire and the terminal from the apparatus.

As the stripped wire end is inserted into the terminal, by the apparatus, in the axial direction of the wire, the terminal may have a wire receiving crimping ferrule of the closed barrel type, that is to say, a ferrule which is tubular rather than being of U-shaped cross section.

In order to take account of a further requirement, that the stripped length of the wire should be accurately determined, so that on the one hand, no uninsulated portion of the wire core projects from the terminal, and so that on the other hand, the length of the stripped end portion that is inserted into the terminal is not so short as to impair electrical connection between the wire and the terminal, the depth to which the end of the wire can be inserted between insulation severing jaws of the insulation severing and stripping unit is controlled by means of a laser beam extending on the side of the jaws remote from the gripper unit which is actuable, immediately the wire end has interrupted the laser beun to ensure that the wire can be no further moved in the direction ol @@@@ d stripping unit, the jaws of which are then actuable to sever the insulation of the wire.

When the operator inserts the wire between wire gripping jaws of the wire gripper unit, to position the wire end between the jaws of the wire severing and wire stripping unit, there should be minimal clearance between the jaws of the wire gripper unit and the wire, not only to ensure that the end of the wire is correctly inserted between the wire stripping jaws but also to avoid too rapid insertion of the wire by the operator, to an extent to cause the stripped length of the wire to exceed that determined by the position of the laser beam relative lo the wire stripping jaws, that is to say to avoid the end of llse wire ?e,ssing sensibly beyond the laser beam. To this end, means are provided lor adjusting said clearance in accordance with the gauge of the wire.

According to said patent application.. - a wire end processing apparatus which comprises u wire gripper unit having wire gripper jaws and means for moving the jaws between a fully open position, a fully closed position and a partially open wire receiving position in which the wire, an end portion of which is lo be processe , can be inserted between the jaws; and a wire processing unit aligned with the wire gripper unit for receiving and processing said end portion of the wire when it has been inserted between said jaws, is provided with means for emitting and sensing a laser beam extending through the wire processing u1it and for causing said jaws fully to close when the end of the wire interupts the laser beam, and is also provided with means for adjusting the exent to which the jaws can close to suid wire receiving position, to ensure thut there is minimal clearance between the jaws and the wire, in dependence upon the gauge of the wire.

Where, as for some uses in .ne Aircraft Industry, the wire is intended to withstand very high temperatues, the wire will comprise a relatively soft outer jacket and a hard, resinous, varnish-like inner insulation covering the metal core of the wire. Such varnish-like insulation is most difficult to sever, and strip from the wire end portion completly, as it tends to crumble.

As set forth in claim 1 herein, insulation severing blades, each comprise a pair of mild steel blade supports between which is sandwiched, an insulation beavering olade made of a hardened steel, for example the kind of steel of which razor blades are made, each blade support having a wire receiving notch arranged in alignment with a wire receiving notch of the other blade support and with a wire receiving notch of the hardened steel blade, which notch is of smaller radius than the wire receiving notches of the blade supports.

It has been fourid that such olades not only cut cleanly through the jacket of the wire but also cut cleanly through the varnish-like insulation and strip it cleanly frpm the metal core of the wire.

For a better understanding of the invention and to show how it may be carried into effect, an em,bodiment tbc:'eof will now be described by way of example with reference to the accompanying drawings in which; Figure 1 is a fragmentary plan view of a strip of tape mounted electrical terminals; Figures 2A to 2F are diagrams illustrating successive stages in a cycle of operation of apparatus for stripping end portions of insulated electrical wires, removing the terminals from the tape upon which they are mounted, and for crimping the terminals to the stripped wire end portions; Figure 3 is a diagramatic rear view of the apparatus, with parts omitted, taken in the direction of tne urrow 4 in Figure 4;; Figure 4 is a diagramatic side view of the apparatus, with parts omitted, taken in the direction of the nrrow 3 in Figure 4; Figure 5 is a ciugramatic s;de view ol electrical terminal supply and pre-feed units of the apparatus, in association with a bottom press jaw thereof; Figure 6 is a diagramatic front view of a wire stripper unit of the apparatus; Figure 7 is a diagramatic side view of the wire stripper unit; Figure 8 is a fragmentary, diagraniatic, exploded, isometric view of a wire stripper jaw of the wire stripper tint; Figure 9 is a diagramatic front view of the wire stripper jaws, in a closed position;; Figure 10 is a diagramatic front vie of at upper, electrical terminal gripping and crimping unit of the apparatus, shown partly in section and depicting part of a lower, electrical terminal gripping and crimping unit of the apparatus, and ,also showing part of the terminal supply unit; Figure 11 is a view taken on the lines 11-11 of Figure 10; Figure 12 is a fragmentary isometric view of an electrical terminal indentor of the crimping unit; Figure 13 is a diagramatic, fragenentary, enlarged sectional view illustrating details of Figures 10 and 11; Figure 14 is a diagramatic front view of a wire gripper unit of the apparatus;; Figure 15 is a diagramatic vice view showi lg part of the gripper unit and wire stripped length adjustment mechanism of the apparatus; Figure 16 is a diagramatic view taken on the lines 16-16 of Figure 14; and Figure 17 is an enlarged fragmentary, isometric view of a wire gripper jaw of the wire gripper unit.

Figure 1 shows a fragment of an indefinite length of electrical terminal carrier tape, generally referenced T, and comprising a base tape BT having a row of tape indexing slots S extending along one margin thereof, and adhered to the tape T by means of an adhesive tape AT, adjacent to the opposite margin thereof, a row of electrical terminals ET having recepticle portions R extending between the tapes BT and AT and circular cross section, tubular crimping ferrule portions CF projecting beyond said opposite margin.

Intermediate its portion CF and R, each terminal ET has a circular radial collar RC positioned just beyond said opposite margin. Each terminal ET can be axially advanced against the action of the adhesive on the tape AT from the position in which the terminal Is shown in full lines in Figure 1, to that in which it is shown in broken lines therein, whilst still remaining adhered to the carrier tape T.

The apparatus disclosed herein is for stripping end portions of insulated electrical wires W (, stripped end portion of one of which is best seen in Figure 13), for removing the terminals ET one by one from the carrier tape T, inserting the stripped erd portion o each wire W into the crimping ferrule portion CF of a terminal ET, and crimping, by indentation, the portion CF onto a stripped end portion the metal core MC of the wire.

The wire W, which is intended to withstand very high temperatures, comprises a relatively soft outer jacket J and a bard, resinous, varnish-like insulation covering the strands of the metal core MC, which is multi-stranded.

The apparatus and its operation will now be described in outline with particular reference to Figures 2A to 2F. The basic components of the apparatus, comprise a fixed wire gripper unit 10, a horizontally reciprocating wire stripper unit 12, a pair of upper, and lower, termianl gripping and terminal crimping heads 14 and 16, respectively, a carrier strip supply rotary conveyor unit 18 and a terminal prefeed unit 20.

At the beginning of a cycle of operation of the apparatus, wire gripper jaws 22 of the unit 10 which is fixed to a front plate of the apparatus, as described below, are in a partially open position and the unit 12 is in a horizontally advanced position with wire stripper jaws 24 thereof in an open position (Figure 2A). The heads 14 and 16 are in an open position remote from the path of movement of the unit 12. The operator inserts a wire W through an opening in the front plate and between the jaws 22 so that the end portion portion of the wire W extends between the stripper jaws 24 and there beyond, so that its free end interrupts a laser beam L behind the jaws 24. The position of the beam L is adjustable as described below for the determination of the stripped length of the wire W.Upon the free end of the wire W interrupting the beam L, the jaws 22 are instantly closed so that the wire W cannot be further advanced between the jaws 24 and the jaws 24 are closed to severe the insulation of the wire W as shown in Figure 2AI, on datum line C. It should be recalled, that the insulation comprises both the Jacket J ane the varnish-like insulation.

The unit 12 has no wire stop for arresting the free end of the wire W, the extent to which the wire W can be advanced between the jaws 24 being determined only by the position of adjustment of the beam L. The insulation having been severed, the unit 12 is then retracted as shown in Figure > B, beyond datum line A, so that the jaws 24 drag the severed portion of the insulation from the core SIC of the wire W, tie stripped end portion of the core MC projecting from the insulation of the wire W, beyond datum line C. The insualtion is always severed on datum line C regardless of the position of the beam L.

A terminal ET angularly positioned acting the next previous cycle of operation by the conveyor unit 18, after having been advanced by prefeed unit 20 from its full line position in Figure 1 to its broken line position therein, so as to be partially ;thdrawn trom between the tapes AT and BT and so to project forwdrdly.from the unit 20 with the free end of the said portion CF of the terminal positioned on datum line B (Figure 2C).

Wire stripping and wire crimping heads 14 and 16 are now closed so that the terminal ET is gripped between clanips 26 on inserts 28 of the heads 14 and 16 as shown in- Figure 2C, such closure of the heads 14 and 16 being enabled by the retraction of the unit 12.

With the terminal ET securely gripped between the clamps 26, the heads 14 and 16 are advanced horizontally relative to the unit 18, towards the unit 10, as shown in Figure 2D so that the terminal ET is completely withdrawn from the tape T and the free end of the portion CF of the terminal is positioned on datum line C whereby the bared end of the core MC of the wire W guided by opposed core guides 30 of the inserts 28 is inserted into the portion CF, after which the heads 14 and 16 are pressed against each other by means, described below, cause indentors 32 of the heads 14 and 16, which indentors extend through the inserts 28 to close about the portion CF to produce four regularly spaced indents therein to crimp it to the bared end of the core MC (Figure 2E). The unit 12 is then advanced again from its retracted position, towards the unit 10 as indicated in Figure 2F, thereby triggering the opening of the heads 14 and 16 and full opening of the jaws 22 so that the operator can pull the terminal ET through the open jaws 22, by pulling on the wire at indicated in Figure 2F, although the tension applied to the wire will be negligible. As explained in detail below, the wire gripper jaws 22 are arranged to be opened to their full extent, to allow the withdrawal of the terminal ET therethrough, and are subsequently partially closed to a further extent, which is adjustable, to allow a further wire to be inserted between the jaws 22 for the next cycle of operation of the apparatus.The extent of this partial closure of the jaws 22, is adjusted in accorcance with the gauge of the wire so that there is minimal clearance between the jaws 22 and the wire when it is Inserted there between. This not only ensures that the end of the wire Is correctly inserted between the insulation severing and stripping jaws 24, but also inhibits too rapid insertion of the wire W by the operator to cause the strippeA length of the wire W to exceed that determined by the adjustment of the position of the beam L relative to the jaws 24. If the wire were too rapidly inserted, its end could pass to a significant extent beyond beam L prior to the closure of the jaws 22.

During a cycle of operation preceding said next previous cycle, the prefeed unit 20 moved forward with the heads 14 and 16 to advance a terminal ET/ from its full line, to its broken line, position, in Figure 1, upstream, in the direction of movement of the conveyor unit 18, of the terminal ET, after which the conveyor was indexed to bring the terminal ET/ to the position o,f alignment of the unit 10, in which the terminal ET/ is shown in Figures 2D and 2E.

The general construction of the apparatus will be be described with particular reference to Figures 3 and 4. In these Figures, the moving parts of the apparatus are shown in full lines in their positions on Figure 2A, that is to say in their starting positions. The apparatus comprises a main frame 34 and secured thereto, the said front plate, which is referenced 36 and to which the unit 10 is fixed, the wire access opening in the plate 36 being referenced 38 in Figure 4.Mounted for horizontal movement in the frame 34 on bearings (not shown) is a press frame 40 for forward and rectractile movement through about 18rim, for example, by means of a piston and cylinder unit 42, secured to the frame 34 and having a piston rod 44 fixed to the frame 40. The upper terminal gripping and terminal crimping head 14 is carried by a horizontal arm 46 mounted on vertical rods 48 which are slidable in linear ball bushings 50 secured to the press frame 40. The arm 46 can be adjusted lengthwise of the rod 48 by means of a micrometer adjustment knob 52 to allow for crimp height, that is to say for terminal size.The lower terminal gripping and terminal crimping head 16 is carried by a horizontal arm 54 which is vertically slidable on linear vall bushings 56, along the rods 48. The rods 48 are connected by fasteners 58 to a cross-piece 60 to which is pivotally connected, the lower link 62 of a press drive toggle link mechanism generally referenced 64, the upper link 66 of the mechanism 64 being pivotally connected to the arm 54 by means of a pivot pin 68, the link 62 being connected to the cross -piece 60 by means of a pivot pin 70. The links 62 and 66 are pivotally connected, by means of pivot pins 76 amd 78, respectively, to a slide 72 which is drivable horizontally by means of a piston and cylinder unit 74.

By activating the unit 74 to advance its piston rod, the slide 72 is driven rightwardly (as seen itN Figure 4), to open the links 62 and 66 from the position in which they are shown in Figures 3 and 4, so that the link 62 lowers the arm 46 to its broken line position and the link 66 raises the arm 54 to its broken line position, to move the heads 14 and 16 from their open to their closed position. There are provided, in order to assist this movement of the arms 46 and 54 towards each other by means of the mechanism 64, to press the inserts 28 together as described above with reference to Figure 2E, upper and lower toggle drive assist piston and cylinder units 80 and 82, respectively. The units 80 and 82, which are oppositely acting, have their cylinders secured to a cylinder support bar 84, which as best seen in Figure 4, is fixed to the press frame 40.The piston rod 86 of the cylinder 80 is fixed to the cross-piece 60 and the piston rod 87 of the unit 82 is fixed to the arm 54. when the piston rod 87 is advanced, it assists the link 66 in driving the arm 54 and tflus the head 16 towards the head 14, and when the piston roc 86 is aX vanced, it assists the link 62 in driving the cross-piece 60 and the arm 46, and thus the head 14 towards the head 16. The arms 48 extend through linear ball bushings 88 fixed to the support 84. The position of the beam L is adjustable by means of a knob 89 on the front plate 36, through a mechanism described below, the extent to which tne jaws 22 be closed from their fully open, to their partially open, position being adjustable by means of a hand wheel 91 projecting from the plate 36, by means of a mechanism described below.

The conveyor unit 18 and the terminal prefeed unit 20 will now be described with particular reference to Figures 3 and 5. These units are mounted on a base 90 which is, in turn, mounted in the arm 54 carrying the lower crimping head 16 which is exchangeably mounted to the base 90 by means of fasteners 95. The conveyor unit 18 is mounted to the base 90 and thus to the arm 54, by means of a dovetail connection which is generally referenced 92 so that a;:hough the unit 18 is raised and lowered with the arm 54, it does not move horizontally therewith as will be apparent from a comparison of Figures 2C and 2D, the unit 18 being connected to the main frame 34 for vertical movement thereon by means of roller bearings (not shown). Thus the conveyor unit .18 is always intersected by datum line A which will be apparent from Figures 2C to 2E and from Figure 5.

in Figure 5, the lower head 16 is shown in its Figure 2C horizontal position in which datum line B lies Jusl Dehind the guide 30 of the insert 28 of the head 16. The dovetail connection 92 comprises a dovetail slideway block 94 having a horizontal channel 96 therethrough and being formed on its upper surface with a dovetail rib 98 which engages in a complementarily shaped groove 100 in a conveyor carrier unlock 102 which is fixed to the main frame 34 by means of said roller bearings. The block 94 is thus slidable relative to the block 102 as the head 16 is moved between its Figure 2C and its Figure 2D positions.The conveyor 18 comprises an endless belt 104 having teeth 106 which engage in the indexing slots S in the tape T which depends from a rotary storage reel (not shown) and over an idler role 108 which is mountea to the block 102 by means of a bracket (not shown).

The conveyor belt 104 is intermittently driven by a stepping device 110 to advance the tape T in a leftward (as seen in Figure 3) direction by the distance between the slots S in the tape T at each step. At its end opposite to the device 110, the conveyor belt 104 is carried by a shaft 111 which is adjustable towards and away from the device 110, for belt tension as indicated in broken lines in Figure 8 The prefeed unit 20 comprises a support plate 112 which is fixed to the base 90 by means of a screw 113, upstream, in the conveying direction of the terminal gripping and terminal crimping head 16, as shown in Figure 3. There are provided on the plate 112, a fixed, terminal prefeed finger 114 and a movable terminal feed finger 116 pivoted to the plate 112 at 118.Fixed to the block 102 by means of screws 119 (Figure 4) is a cam follower support 120 upon which is mounted for free rotation aoout a pivot pin 124, a circular cam folower 122 for co-operation with a cam surface 126 on the finger 116. At its end remote from the cam surface 126 and on the other side of the pivot pir. 118, the finger 120 has a downwardly projecting, terminal engaging nose 128 disposed oppositely to an upwardly projecting terminal engaging nose 130 at the free end of the finger 114.

The finger 116 is urged in an anti-clockwise (as seen in Figure 5) sense of rotation about the pin lld ny a coil spring 132 acting between the finger 126 and the plate 112. When a terminal ET/ has been positioned by the conveyor unit 18, in front of the fingers 114 and 116, as the head 16 is advanced from its Figure 2C to its Figure 2D position, the terminal ET being in its full line position in Figure 1, the fingers 114 and 116 are moved towards the terminal ET/ in the open position in which they are shown in Figure 5, until the noses 128 and 130 of the fingers 114 and 116 approach the radial collar RC of the terminal ET/ at which time, the cam follower 122 rides onto a reduced height tlat end portion 134 of the cam surface 126 so that the finger 116 is urged by the spring 132 in its anticlockwise sense of rotation about the pin 118 whereby the noses 128 and 130 are relatively closed about the terminal ET/ and engage the collar RC thereof as indicated in broken lines in Figure 5 so that as the head 16 continues its advance, the terminal ET/ is drawn from between the tapes AT and BT to assume its broken line, Figure 1 position.Although the travel of the head 16 is such that the terminal ET Is advanced so that the tip of its crimping ferrule portion CF projects slightly beyond datum line B, a cam bar 133 (Figure 3) secured to the block 102 alongside the belt 104 and downstream of the fingers lli and 116, forces the terminal ET/, to a small extent, back, so that the tip of its ferrule portion CF is coincident with datum line B, correctly to position the terminal ET/, for a further cycle of operation of the apparatus.

The wire stripper unit 12 will now be described with particular reference to Figures 6 to 9. The stripper unit 12 comprises a frame 140 mounted on a slide 141 which is slidable horizontally, and laterally of the apparatus, relative on a slide unit 142, as indicated in broken lines in Figure 3, by means of a click-stop micrometer adJustment knob 144. In the frame 140 are vertical slide rods 146, upon which are slidably mounted, in opposed relationship, upper and lower stripper.jaw slides 148 and 150, respectively, for vertical movement on linear ball bearings 152, along the rods 146.

The slides 148 and 150 are movable towards and away from one another by means of pneumatic piston and cylinder units 151 attached to the slides 148 and 150 and having piston rods 153 secured to the frame 140 by means of screws 155. There is provided on the upper slide 148, a first jaw carrier plate 154 and on the lower slide 150, a second jaw carrier plate 156, engaging in a recess 158 in the plate 154 in order correctly to align the stripper jaws 24, each of which is secured to the rear of a respective one of the plates '54 and 156. Each stripper jaw comprises a pair of mild steel, insulation severing blades supports 158/send 159 (Figure 8) and sandwiched therebetween, a hardened steel insulation severing blade 160 blade, made for example, from razor blade material.Each support 158 and 159 is provided with a row of wire receiving notches 162 to 167 of arcuate shape, and which, as seen in Figure 9, increase in radius form right to left, although these gradations in radius are not to be seen in Figure 8, in which the notches are shown only diagramatically. Each jaw 24 is secured to its respective plate 154 or 156, by means of studs 168 passed through openings 170 in the supports 158 andes 159 and openings 172 in the blades 160, lugs 174 on the supports 158 engaging in recesses 176 and 178, respectively, in the blades 160 and the supports 159 to hold each pair of supports 1581and 159 in precise alignment with the respective blade 160, so that a pair, of equal radius, of the notches 162 to 167 is aligned with a corresponding notch 162/ to 167/ in the blade 160, each notch 162/ and 167 being of smaller radius than the corresponding notch 162 to 167 as best seen in Figure 9, in which the jaws 24 are shown in their closed position. Proximity sensors 180 are provided in the frame 140 sensing the open and the closed positions of the jaws 24. The slide unit 142 serves for positioning a desired set of aligned wire receiving notches in alignment with the opening 38 in the front plate 36, in accordance with the gauge of the wire W from which insulation is to be stripped, the slide 141 being retained in a desired horizontal position corresponding to the selected wire gauge, by means of a lock nut 182 on the slide unit 142.

The laser beam L is generated by a laser emitter 184, the interruption of the beam L being detected by a laser sensor 186, the emitter 184 and the sensor 186 being adjustable forwardly and rearwardly of the apparatus by means described below, in order to determine the length of the core MC of 'he wire W, that is to be stripped. When the jaws 24 are closed about the wire W, the edges of the respective notches in the blades 160, which have been aligned with the opening 38 in the front plate 36, cut cleanly through the jacket J of the wire W and also cut cleanly through the varnishlike insulation on the strands of the core MC thereof, and as the unit 12 is retraced, scrape that insulation cleanly from the strands.

The terminal gripping and terminal crimping heads 14 and 16 will now be described with particular reference to Figures 10 to 13 and mainly with reference to the upper head 14. The head 14 comprises a body 188 having an upper part A90 and a lower part 192, the part 190 being vertically slidable towards the part 192 on rods 194 against the action of compression springs 197 (Figure 10).There are fixed to the part 190 two opposed pairs of coplanar indentor cam plates 196, by means of fasteners 198 which extend through vertical slots 200 in the plates 196, so that the vertical position thereof can be adjusted by means of screws 202 threaded through a top plate 204 of the part 190, the plate 204 being secured to the part 190 by means of a screw 206. Within the body part 102, each plate 196 is formed with a cam slot 208 which extends obliquely downwardly (as seen in Figure 10) and opens into the bottom end of the plate 196, the slots 208 of each pair of coplanar plates 196 being downwardly divergent.There is slidably arranged in a groove 210 in each plate 196, one of the four indentors 32, each indentor 32 having a cam otower end surface 212 enguging an outer camming edge 214 of the respective slot 208. As best seen in Figure 12, each indentor 32 has an indenting nose 216 projecting from its end opposite to the cam follower surface 212. A part of each indentor 32, back from its nose 216, extends through an opening 218 in the insert 28 of the jaw 14 so that the nose 216 projects into said insert.The terminal gripping and terminal crimping head 16 is identical with the head 14, but is arranged there below in mirror image relationship therewith, so that in relation to the head 16, the words "upper" and "lower", as used in the above description relating to the head 14, are reversed in the case of the head 16.

When the heads 14 and 16 have been brought to their closed positions about the terminal ET and are pressed together (Figure 2e) with the aid of the piston and cylinder units 80 and 82, the parts 190 and 192 of each head 14 and 16, are driven towards one another against the action of the springs 197, since the inserts 28 are in abutment, so that the indentors 32 are simultaneouslyi forced radially inwardly of the crimping ferrule portion CF as the cam follower surfaces 212 thereof slide on the cam surfaces 214, whereby the nose 216 of each indentor 32 is driven into the crimping ferrule portion CF of the terminal ET so that it is firmly and permantely crimped to the bared portion of the core MC of the wire W.

The mechanism for tidJusting the position of the beam L for wire stripped length, will now be described with particular reference to Figures 14 and 15. The laser beam emitter 184 and the laser beam sensor 186 are mounted on a two armed yoke 220 the lower end of which is mounted to the front plate 36 by way of pivot pins 222 in a bearing block 224 fixed to the plate 36 by means of screws 226, the yoke 220 being swingable about the pins 222 away from the panel 36 agains the action of springs 228, The knob 89 is secured to a screw threaded spindle 230 meshing with an internally tapped bushing 232 (Figure 15) so that rotation of the knob 89 by one revolution, will, for example, move the bushing 232 by one millometer towards or away from the panel 36 according to the sense of rotation of the knob 89.The bushing 232 is enclosed in a housing 234 fixed to the panel 36 by means of screws 236 and having opposed slots 238 therein through which extends a pin 240 fixed to a yoke displacement nose 242 engaging a plate 244 secured to one arm 248 of the yoke 220 by means of screws 246 and carrying the sensor 186 which is thereby secured to the arm 248 of the yoke 220, the emitter 284 being connected to the other arm 250 of the yoke 220 by means of a plate 252 secured thereto by screws 254.

By turning the knob 89, the beam L can be moved towards and away from the jaws 24 to adjust the stripped length of the core MC of the wire W.

The wire gripper unit 10 will now be described with particular reference to Figures 14 to 17. Each of the jaws 22 comprises a shank 256 (Figure 16) from which project a series of five spaced jaw plates 258 from each of which projects a w?re gripping, triangular shaped, finger 260. The fingers 260 of the jaws 22 slidably interdigitate to define a square, wire receiving opening 262 (Figure 14), the jaws 22 being slidable towards and away from one another on the front plate 36 in a housing generally referenced 264 thereon, by means of screws 265, the fingers 260 being contained in a circular portion 266 of the housing 264. Mounted for rotation about the pbrtion 266 is an outer (as seen in Figure 16) cam wheel 268 having formed in its peripheral cam surface, two diametrically opposite sets of five steps 271, an inner (as seen in Figure 12) cam wheel 270 also being mounted for rotation about the housing portion 266 in juxtaposed parallel relationship with the cam wheel 268. The inner cam wheel 270 has diametrically opposed steps 269. The housing 264 has end casings 272 receiving respective end portions of the jaw shanks 256, each casing 272 having adjustably secured to an end wall 274 thereof, by means of a screw 278, a loading spring 276, each spring 276 engaging in a well 280 in the respective jaw shank 256, so that the springs 276 urge the jaws 22 towards one another.The screws 278 serve to adjust the tension of the springs 276, in turn to adjust the force that the fingers 260 of the Jaws 22 exert against a wire W to be gripped by the unit 10 in the fully closed position of the jaws 22. On each shank 256 ic a cam follower 282 which is engagable with the cam wheel 268 or 270 according to the angular positon thereof. A piston and cylinder unit 284 has its piston rod 286 pivotally connected by a pin 288 to a lug 290 projecting radially outwardly of the inner cam wheel 270. The cylinder of the unit 284 being pivotally connected by a pin 292 to a bracket 294 secured to the front plate 36 by means of fasterners 295.A further piston and cylinder unit 296 has its piston rod 298 pivotally connected by a pin 300 to a lug 302 projecting radially from the outer cam wheel 268, the cylinder of the unit 296 belr:g connected by means of a pivot pin 304 to a lever 306 loaded byla spring 307 and connected to a spindle 308 of a toothed wheel 310, the spindle being rotatable in a bracket 312 secured by screws 314 to the front plate 36. The hand wheel 91 has a shaft 316 to which is keyed a worm wheel 318 meshing with the teeth of the wheel 310. The hand wheel 91 is rotatable stepwise, by virtue of a ball detent 320 mounted in the bracket 312 and being engageable in recesses (not shown)in the periphery of the wheel 91. inductive sensors 322 are provided on each side of the opening 262 for sensing the presence of a wire W therein.

Figure 14 shows the piston and cylinder unit 284 in a position in which the jaws 22 are fully open to allow the terminal ET crimped to the wire W to be pulled between the jaws 22, each cam follower 282 resting on a selected step 271 of the cam wheel 268. The extent to which the jaws 22 close, in their partially closed position can be adjusted for the purpose mentioned above, by means of the hand wheel 91 acting through the toothed wheel 310, the worm wheel 318, the lever 306 and the unit 296, to alter the angular position of the cam wheel 268 to place a desired step 271 opposite to each cam follower 282 thereby to determine the extent to which the jaws 22 interdigitate with one another in their partially closed position and thus the area of the opening 262, in that position, to allow for wire gauge.When the jaws 22 are to be partially closed, the unit 284 is actuated to retract its piston rod 286 in an anti-clockwise (as seen in Figure 14) sense, to a position in which its steps 269 pass the cam followers 282 to allow them to engage said selected steps 271 of the cam wheel 268, the unit 296 being actuated to retract its piston rod 298 to bring about full closure of the jaws 22 when the beam L is interrupted the end of a wire W.

When a wire W with a terminal ET crimped thereto is withdrawn through the opening 38, as described with reference to Figure 2F, the jaws 22 being in their fly opened position to allow of this, the sensors 322 are deactivated by the wits awful of the wire W and the terminal ET therebetween, to cause the unit 284 to retract its piston rod 286 so that the jaws 22 partially close to an extent determined by the setting of the knob 89.When a further wire W has been inserted through the partially closed opening 262, by way of tne opening 38 in the front plate 36, and into the unit 12 to interrupt the beam L, the sensor 186 is deactivatea to cause the piston and cylinder unit 296 to advance its piston rod 298 to rotate the cam wheel 268 in a!l anticlockwise (as seen in Figure 14) sense to position a low portion 323 of the profile of the cam wheel 268 opposite to each cam follower 282, to allow the jaws 22 to be fully closed under the action of the springs 276, fi about the wire W, to exert a pressure thereagainst determined by the settings of the screws 278.

When the unit 12 is advanced again towards the unit 10, as described with reference to Figure 2F, with its jaws 24 in their open position, the unit 284 is triggered by a limit switch (not shown) to advance its piston rod 286 to rotate the cam wheel 270 in a clockwise (as seen in Figure 14) sense so that the cam followers 282 ride up on the steps 269 of the wheel 270, fully to open the jaws 22 to allow the terminal ET crimped to the wire to be pulled out from between the jaws 22 and the unit 296 is triggered to retract its piston rod 296 to reset the cam wheel 268 so that the cam followers 282 again engage the steps 271 selected by means of knob 91.

The sequence of operation of the parts of the apparatus, as described above is carried out under the control of a programable logic controller in accordance with the program thereof.

Claims (2)

1. An insulation severing and stripping unit comprising a pair of insulation severing jaws, each jaw comprising a pair of mild steel blade supports between which is sandwiched an insulation severing blade made of a hardened steel, each blade support having a wire receiving notch arranged in alignment with a wire receiving notch in the other blade support and with a wire receiving notch in the hardened steel blade, which notch, is of smaller radius than the wire receding notches of the blade supports.

2. An insulation severing and stripping unit as claimed in claim 1, substantially as hereinbefore described with particular reference to Figures 7-9 of the accompanying drawings.