GB2191639A - Stripping electrical cables - Google Patents

Abstract

An insulated conductor to be stripped is fed to opening 32 in cutters 24, 25. The presence of a cable is sensed at 35 and an electromagnet 19 is actuated to clamp the jaws 22, 23 and to operate the cutter 25 to cut the insulation to a predetermined depth. A set screw 40 is used for adjusting the cut-off length. After a short delay, drive unit 1, 2 actuates a roll 3 and ram 5 and the cut insulation is removed by moving the parts 42, 43 to the left. The lever 35 moves the separated piece of insulation into a container 36. The jaws and the cutters are reset by the drive unit cycle. It is stated that the stripping unit 10 and the clamping unit 14 can be operated by the drive unit through separate drive lines or phases, the length and/or depth of cut is settable independently of the drive. <IMAGE>

Description

SPECIFICATION Apparatus for stripping electrical conductors The present invention relates to an apparatus for stripping electrical conductors.

In the known conductor stripping apparatuses the cutting and removal of the conductor insulation takes place by means of cutting and displacement devices connected to a movable drive part. It is necessary to adjustthe stripping unit to suitthe particular conductor and electrical connection element to be attached to it, particularly accuracy being required when establishing the cutting position ofthe conductor to be stripped with respect to the prepared connection element, e.g. plug.

Such adjustments are very time-consuming and often involve a tool change, it being in particular necessaryto bring about coincidence between the settings of the stripping apparatus and the settings of the actuating parts of the drive mechanism.

The present invention aims to provide an apparatus permitting simple setting ofthevalues necessaryforthe required stripping operation, so that high precision is ensured together with reduction in the down times necessaryfor setting changes.

According to the present invention there is provided an apparatusforstripping electrical conductors comprising a frame supporting a conductor clamping device and an insulation stripping device, the clamping and stripping devices being operable independently of one another, driving means for operating the clamping and stripping devices, cam means actuable by the drive means through a roll and ram for operating insulation removal means ofthe stripping device and enabling adjustment ofthe insulation stripping length and/or depth.

The conductor clamping device and the stripping device are operable by a single drive unit but via separate drive connections or phases, and the adjustment settings necessary for the required stripping can be set exclusively on the stripping device and independently of the drive arrangement.

In a preferred embodimentthe clamping device has upper and lower clamping jaws. By locking the lower clamping jaw in an open position by means of aforked lever operated bya lifting magnet, and by opening the movable part of the stripping knife by means of a transmission lever and then holding it open by the action of a pawl, it is possible to make ready the conductor clamping and stripping devices readyfor a stripping operation initiated by actuating the lifting magnetto pivotthe lever and release the lower clamping jaw and the movable knife part. The lifting magnet may be controlled by a device, e.g. a light barrier or an electronic component, arranged to sense the presence of a conductor in position ready to be stripped.

An embodiment of the invention is described in detail belowwith reference to the accompanying drawings, in which: Figure lisa side view of an apparatus according to the invention; Figure2 is a front view of a conductor clamping unit ofthe apparatus according to Figure 1; and Figure 3 is a section through the apparatus taken along lineA-A of Figure 1.

The sequence ofthe drawings need not coincide with the movement sequence ofthe inventive apparatus. The specific technical description is mainly based on constructional considerations.

The apparatus illustrated in Figures 1 to 3,31 has a framewhichsupportsaconductorclamping unitl4 and a stripping unit 10 with insulation removing means 24,24', 25,25', 33,34,35,40,41,42,43.

There is a drive connection between the inventive apparatus and a per se known drive unit, e.g. a crimping press 1,2. Drive unit 1,2 acts on a roll 3 with ram 5, whose end remote from roll 3 is constructed as a cam 4. The ram is fixed between two sliders 6,6', which are guided on vertical guides 7,7'. Afurther roll 8 with a lever 9 movably located thereon and mounted on a fulcrum 11 acts on cam 4, the movement of the latter being transmitted to an insulation removal means 42,43, the lever end 9 remote from the roll 8 being pressed, counter to the tension of a compression spring 41, on to an actuating cam arm 43 of insulation removal means 42,43.

By means of a push rod 1 2,the drive unit 1,2 drives the conductor clamping unit 14 having clamping jaws 22,23 and via a push rod 13 and a roll 115 carried on a pivoted lever 16 the drive unit is arranged to move the complete stripping unit 10 outside the crimpingzoneforeliminating insulating residues.

The lateral displacement of stripping unit 10 takes place by means of guide rails 17,17', and return springs 18' ensure at the end ofthe stripping process an automatic return of the stripping unit 10 to its original position.

There is also a solenoid or lifting magnet 19, whose armature is connected to a forked lever 20 mounted in rotary manner and on which engages a locking pawl 21 of a movable knife part 25. The lower clamping jaw 23 is locked by means of the forked lever 20 counterto the force of a spring 30' which is compressed through the pressure of push rod 12 on the upper clamping jaw. In the lower part ofthe frame 31 are provided knife supports 25' carrying fixed and movable knife parts 24,25. The movable knife part 25 is acted upon by a return spring 26 and co-operates with the pawl 21, the movable knife part 25 being kept in the open position by the locked pawl 21 counterto the tension of return spring 26.The return movement of the movable knife part25takes place by means of a transmission lever 27,which is connected to slider6 and whose other end is constructed as a slideway 28 for coacting with a cam 29 of knife support 25'.

Theconductorclamping unit 14 is operated by means ofthe push rod 12 of derive unit 1 ,2,which presses on the upper clamping jaw mounting support 22 in opposition to spring 30, and through this spring on the lowerclampingjawmounting support23 in opposition a furtherspring toafurther spring 30'. As has already been stated, the lower clamping jaw 23 is either locked or released by means oftheforked lever 20 of lifting magnet 19, so thatthe clamping jaws 22,23 are opened or closed.

The apparatus functions as follows. By inserting a conductor end between the clamping jaws 22,23 opened in accordance with Figure 2, and with the knife parts 24,25 opened and forming an opening 32, a signal is emitted by a preferably electronic device, such as a sensor 33, so that lifting magnet 19 unlocks forked lever 20 and simultaneously the pawl 21. As a result clamping jaws 22,23 and the movable knife part 25 close, so that the conductor is clamped and its insulation is cut through to a predetermined depth. The cut depth is adjustable e.g. by means such as a screw limiting the movement ofthe knife part 25 underthe action ofthe spring.Following a short delay, the drive unit 1,2 actuates roll 3 with ram 5 and the cut conductor insulation is removed by the insulation removal means 42,43 which is driven to the left as seen in Figure 1 by means of roll 8 and lever9 in opposition to the spring 41. Push rod 13 of drive unit 1,2then acts on roll 15, so thatthe pivoted lever 16 moves the complete stripping unit 10 out of the crimping zone in opposition to the tension of compression springs 18'. Simultaneously, the knife support 25' with the movable knife part 25 is opened by means of the slideway 28 ofthe transmission lever 27 acting on the actuating cam 29. During the opening movement of knife part 25 an ejection lever 35 movesthe separated piece of conductor insulation into a container 36, through the action of an abutment pin 34 located on transmission lever 27.

At the bottom dead centre position of drive unit 1, 2 the clamping jaws 22,23 are forced downwards by push rod 12, in the manner described hereinbefore and the lowerjaw is locked bythe lifting magnet 19 and forked lever 20. By raising the lifting member 2 of drive unit 1 the apparatus is returned to its initial position,i.e.thatofbeing readyforreceivingthe next conductorto be stripped and the previously described process is repeated.

For adjustment and tool changing operations, it is possible to swing the complete apparatus laterally outwards by means of a bolt 37, which traverses a base plate 38 and a fixing plate 39 and thereby simplifies accessibilityto the setting means.

For adjusting the cut-off length of the conductor insulation, the apparatus carries a setscrew40,so that it is possible to use a wide variety of conductor types.

Claims (8)

1. An apparatus for stripping electrical conductors comprising a frame supporting a conductor clamping device and an insulation stripping device,the clamping and stripping device being operable independently of one another, driving means for operating the clamping and stripping devices, cam means actuable by the drive means through a roll and ramforoperating insulation removal means ofthe stripping device and enabling adjustment ofthe insulation stripping length and/or depth.

2. An apparatus according to claim 1, wherein the ram is guided by sliders carried on substantially vertical guides and supporting a transmission lever having a cam slidewayforoperating insulation cutting parts of the stripping device.

3. An apparatus according to claim 1 or 2, wherein a cam face movable with the ram is arranged to co-operate with a roll carried on a lever for pivoting the leverforoperating the insulation removal means.

4. An apparatus accordingto claim 1,2 or 3, wherein the stripping device includes insulation cutting means having a fixed knife support, a movable knife part, a spring acting on the movable knife support and biasing the movable supportto a closed position, and a pawl for locking the movable support in an open position.

5. An apparatus according to any one of claims 1 to 4, wherein the driving means includes a push rod for engaging a roll supported on a pivoted leverfor displacing the stripping device laterally along guide rails mounting the device, return springs being provided for return movement of the stripping device.

6. An apparatus according to anyone of claims 1 to 5, wherein the conductor clamping device comprises upper and lower resiliently supported clamping jaws, and is arranged to be operated by the driving means th rough a push rod.

7. An apparatus according to claim 6, wherein the lower clamping jaw is arranged to be selectively locked and unlocked buy a mechanism comprising an actuatoranda levercoupledtotheactuator.

8. An apparatus for stripping electrical conductors substantially as herein described with reference to the accompanying drawings.