CH635469A5 - APPARATUS FOR STRIPPING ELECTRIC WIRES. - Google Patents

Description

The present invention relates to an apparatus for stripping electric wires to remove the insulation from the end of the conductor of an electric wire, this apparatus comprising a pinching device for pinching the wire, and a cutting device equipped with knives arranged for move closer to each other, in order to cut the insulation of the wire and to withdraw from the conductor the insulating section thus separated, the clamping and cutting devices being able to be mutually adjusted and put into service by driven control means by a motor.

An apparatus of this type has been described in the German patent application published before examination No. 24 16 499. The wire,

from which the insulation must be removed, is inserted between two pinch jaws, before the insulation is cut and then removed from the wire. This device makes it possible to remove the insulation from electrical wires, the conductor of which has a cross section of 0.14-1.5 mm 2. One of the drawbacks of this device is due to the fact that pinching of the insulation, on two sides , shapes teeth and can cause damage to the insulating jacket. Another drawback stems from the fact that the notch of the insulation is only practiced on two sides, the part of the insulation, intended to be removed, is only partially separated from the insulating envelope, which prevents making a clean cut when the separate section is removed from the rest of the insulating jacket. These drawbacks can lead to conditions which are unacceptable for the subsequent use of the wire thus stripped, for example when the insulation has not been completely removed, the part of the remaining insulation must be removed manually before welding the conductor, ie welding is not possible in the presence of an insulating residue.

On the other hand, this known device does not allow to remove, from an electric wire, an insulator made of a very hard synthetic material, so that the possibilities of using this device, according to the prior art, are really very limited.

The object of the present invention is to provide an apparatus of the above-mentioned type, in which the above-mentioned disadvantages and disadvantages are eliminated and in which different types of wire insulation can be quickly, cleanly and simply removed from the conductor. The removal of the insulation begins with the insertion of the end of the wire into the device, without the risk of bending this end even when the wire has a very small diameter, after which the insulation is removed completely automatically.

According to the invention, the problems mentioned above are solved by the production of an apparatus for stripping electrical wires defined as described in claim 1.

According to the invention, the clamping mandrel employs at least three jaws to effect effective clamping of the electric wire. The spacing between these jaws can be adjusted, so that the device can be used for different wire diameters. A suitable automation allows this adjustment to be made from the outside, by means of a button and a graduated scale. This automatic mechanism also allows the cutting diameter of the knives to be adjusted simultaneously, so that the insulation can be completely removed without damaging the conductor, even when the wire size is changed.

According to an embodiment of the present invention, the cutting head uses three knives. This realization produces a circumferential notch, capable of ensuring a clean separation of the insulation in all conditions. An additional device controls the movement of the knives during stripping, in order to carry out the complete or partial removal of the insulation.

The switching means, which make it possible to detect the insertion of the wire to be stripped, require such a low mechanical force that there is no risk of bending the wire,

whatever its diameter. The length of the insulating section to be removed is determined by the positioning of the switching means along the reference axis defined by the insertion opening. The apparatus comprises means for withdrawing these switching means axially when the wire is stripped, in order to produce a clearance for the piece of insulation removed.

Advantageously, the control means comprise multiple cams, mounted on a motor-driven shaft, and operate by means of connecting rods fixed to the elements of the apparatus to cause the closing of the mandrel, the closing of the knives, the axial movement of the cutting head, and to keep the motor circuit closed during the complete operational cycle. A specific mechanical device is described using four cams, one for each of the listed functions.

The clamping mandrel preferably comprises three clamping jaws regularly spaced around an axis of symmetry and arranged to move in synchronism at an equal distance from this axis. The cutting head is coaxial with the clamping mandrel and mounted at the rear of the latter relative to the direction of introduction of the wire. The cutting head comprises at least three knives spaced regularly around the axis of symmetry and able to move in synchronism and at equal distances from this axis. The cutting head can be moved axially relative to the mandrel along the axis of symmetry. The clamping mandrel and the cutting head are adjustable according to a determined diameter of the insulator or the conductor by unique adjustment means. Behind the cutting head 30, in the direction of introduction of the wire, are the switching means sensitive to a low pressure, to start the drive motor of the control means.

By the use of at least three clamping jaws and at least three knives, the clamping of the wire, from which the insulation must be removed, and more specifically the cutting, are improved, since three or more jaws nipping and cutting knives, regularly arranged around the insulating sheath of the circular cross-section wire, can conform more precisely to the shape of the conductor than the two jaws and cutting knives used in known devices. Since the insulation of the wire can be notched on its entire circumference, and cut to the wire conductor, or at least until its immediate proximity, it is possible to remove the insulation from the wires including the insulating sheath is made of 45 extremely hard insulating material. Finally, the switching means used, which are sensitive to very low pressures, make it possible to remove the insulation from electrical wires having very small cross sections, for example 0.05 mm 2, without risking bending the front end. of the con-50 conductor, when it is introduced into the device and comes into contact with the stopping of the switching means.

The present invention, its features and its advantages, will be better understood with reference to the description of exemplary embodiments and the attached drawing, in which:

55 FIG. 1 is a perspective view of the apparatus for stripping electrical wires according to the invention,

Figure 2 is a partially sectioned top view of the apparatus of FIG. 1,

FIG. 3 is a partially cut away front view of this device 60,

Figure 4 is a sectional view of the apparatus along the line

IV-IV of fig. 3,

Figure 5 is a sectional view of the apparatus along the line

V-V of fig. 3,

65 Figure 6 is a sectional view of the apparatus along the line

VI-VI of fig. 3,

FIG. 7 is a partially cut rear view of this device,

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Figure 8 is a front view of the apparatus from which the protective casing has been removed, and in which the clamping head or clamping mandrel is in the rest position, this mandrel being adjusted to adapt to a diameter d maximum insulation, 5

FIG. 9 is a front view of the device in which the mandrel is in the rest position, and is adjusted to adapt to a minimum insulation diameter,

FIG. 10 is a front view of the device without the protective housing and without the pinching head, the cutting head being represented in the rest position,

FIG. 11 is a top view of the device without the protective housing,

Figure 12 is a sectional view of the apparatus along line XII-XII of FIG. 10, l5

Figure 13 is a sectional view of part of the apparatus seen along line XIII-XIII of FIG. 11,

Figure 14 is a sectional view of the apparatus along line XIV-XIV of FIG. 2,

FIG. 15 is a front view of the control cam 20 of FIG. 14, and represents the profile of the cam on an enlarged scale,

FIG. 16 represents a mounting support for the control lever of the switching device,

FIG. 17 represents the circuit diagram of the means 25 for controlling the engine of the apparatus,

FIG. 18 represents an adjustment device for the switching device in the rest position,

FIG. 19 illustrates an adjustment device for the switching device in the operational position,

FIG. 20 represents an enlarged longitudinal section view of the pinching head of the apparatus,

FIG. 21 is a front view of the pinching head,

the pinch jaws of which are shown in broken lines, 35

FIG. 22 represents an enlarged longitudinal section of the cutting head of the apparatus along the line XXII-XXII of FIG. 23,

FIG. 23 is a front view of the cutting head of FIG. 10 and represents the knives, 40

Figure 24 is a sectional view of the cutting head along line XXIV-XXIV of FIG. 22,

FIG. 25 is a longitudinal section of the switching device of the device,

FIG. 26 represents the curve of the switching cam activating the limit switch of the motor control device,

Figure 27 shows the curve of the pinch cam, Figure 28 shows the curve of the stripping cam, and 50

Figure 29 shows the curve of the cutting cam.

As shown in fig. 1, the device 1 described is intended to remove the insulation from an electric wire 2 and mounted inside a protective housing 3. The end of the wire 2, surrounded by the insulation 4 intended to be removed , can be inserted into an opening 555 of the housing 3 in the direction of the arrow D, until the wire 2 comes to bear against the switching device 6 of FIGS. 5 and 25. At this time, a motor 7 is started. At the end of the operational cycle, that is to say after the insulation of the wire 2 has been removed, the motor 7 is deactivated and the section of insulation 4 is rejected 60 as waste in a receptacle 8 located under the shape of a drawer, which can be inserted into the housing 3 from the outside and which is emptied regularly. The shafts 12, 13 and 14, each of which protrudes from the wall of the housing 3 of the apparatus 1 and respectively carrying the buttons 9, 10 and 11, are used to adjust the apparatus 1 to varying working conditions, such as described in more detail below. The position of each of the buttons 9 and 10 can be read respectively on the scales 15 and 16. The position of the button 11 is indicated on the scale 17 of FIG. 2. The components of the device 1 and their operation are explained with reference to figs. 2 and following.

As shown in fig. 5 and 25, the switching device 6 is provided with a switching member 19 arranged to slide inside the tubular housing 18, and with a contact rod 22 whose rear end is connected to the motor 7 by the 'Intermediate of an electric wire 45; the contact rod 22 is embedded in an insulating body 29, cooperating with a contact surface 20 disposed at one end of the switching member, and spaced from it by the axial distance 21, the insulating body being adjustable inside of the housing 18 by means of an adjustment screw 28.

The front end of the switching member 19 has a stop 23 standing outside the housing 18. A spring 25, tending to push the switching member 19 out of the housing 18 in the axial direction, is disposed between the stop 23 and a shoulder 24 inside the housing 18. A sleeve 27 which enters the switching member 19 in the radial direction and which can be moved in the axial direction with its two ends arranged in elongated slots 26 arranged in the housing 18, prevents the switching member 19 from being pushed out of the housing 18 beyond a certain position in the axial direction, by the action of the spring 25. The switching member 19 can be moved in the axial direction by a force acting in the direction of the arrow D, to compensate for the bearing force of the spring when the switching member 19 is moved, so that the space 21, separating it from the contact rod 22, decreases.

The force, which is necessary to cause the axial displacement and which acts on the stop member 23 of the switching member 19, depends on the elasticity of the compression spring 25. During the operation, the force acting on the contact member 23 of the switching element 19 is transmitted by the end of the wire 2 intended to be stripped. The force required should be minimized, in particular because the insulation must be removed from conductors having an extremely small cross-section. If the force required to engage the switching device 6 exceeds the bending resistance of the wire 2, the end of the wire 2 curves before the insulation can be removed.

The space 21 (fig. 25), between the contact surface 20 of the switching member 19 and the contact rod 22, can be adjusted by means of the adjusting screw 28 placed inside the housing 18 to reduce the space 21. In this way, the force exerted by the spring is kept constant. Therefore, it is possible to compensate for manufacturing tolerances.

The previously described contact of the switching member 19 comprises the contact rod 22 which closes the circuit of the motor 7, which activates the motor, and as shown in FIGS. 3,6, 8,9 and 10, causes the shaft 95 to rotate clockwise. Fig. 11 shows the shaft 95 carrying a pinch cam 91, a cutting cam 92, a cam for removing the cut insulation 93 and a switching cam 94. In the motor circuit 7, another switch, called a switch limit switch 96, is connected in parallel with the switching device 6; the switch 96 can be engaged by the switching cam 94 of the shaft 95, as shown in FIGS. 11 and 17.

When the switching device 6 has been previously closed, the limit switch 96 is closed by means of the switching cam 94 driven by the motor 7. During a work cycle, the contact of the switching device 6 is interrupted by the movement of the cutting head 50. At the end of the working cycle, the switching cam 94 allows the limit switch 96 to open, which has the effect of bringing the motor 7 (of the brake motor type), the shaft 95 connected to the motor and the cams 91, 92, 93 and 94 fixed to the shaft 95, at a stop in the initial position, for example in

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their rest positions. When the switching device 6 is closed again, the motor 7 is activated so as to affect a complete working cycle. The curve of the switching cam 94 is shown in FIG. 26. According to a preferred embodiment, the motor 7, mounted in the apparatus, has a torque of 0.9 Nm. This value is sufficient to reach gripping forces of 160 N, cutting forces of 100 N and withdrawal forces of 120 N. The apparatus described can be used on wires having conductors with a cross section ranging from 0.05-2.50 mm2. This relatively large range makes it necessary to adjust the device to the diameters of the insulation of the wires 2, from which the insulation will have to be removed. The description below specifies the operation of this adjustment.

Before operating the device 1, the buttons 9, 10 and 11 are used to adjust it to the desired or required conditions (see fig. 1).

The length L of the insulation to be removed from the wire is adjusted by button 9 (see fig. 5,18 and 19). The rotation of the button

9 can be followed using the needle 31 on the scale 15, on which are carried the lengths of the sections of insulation intended to be removed (for example lengths ranging from 2 to

10 mm).

The shaft 12, which is connected to the button 9 supported by a frame 32 and extending parallel to the axis of symmetry 55 of the cutting head 50 and the pinch mandrel 51 (described in more detail below), cooperates with a screw drive 33 and axially displaces a rod 34 in the directions R and V; the rod 34 is mounted coaxially with the shaft 12.

A support 35, which can be moved linearly in the directions R and V, is fixed to the frame 32 by means of the screws 120,121 (see fig. 18,19), which allow the support to slide under the heads of the screws. For this purpose, the support 35 has an elongated slot 122 extending in the direction of movement (fig. 16). A sliding member 123 is provided on the frame 32, between the screws 120, 121 (fig. 17). The support 35 carries a block 125 having a thread 124. A bolt 97, screwed into the thread 124, is used to mount, in a rotary manner, a control lever 36 to the block 125 of the support 35. During the operation, the upper end 38 of the control lever 36 is pushed against the free end 41 of the rod 34, by means of a tension spring 39, the other end of which is fixed to a pin 43 engaged radially in the rod 34 (see figs 5,18 and 19). The lower end 40 (which is the lower end during the operation), preferably having the shape of a double fork, of the control lever 36, surrounds the two ends of the pin 42 which penetrate, through a tongue 30, in the switching device 6. During the operation, the switching device slides in an axial direction inside a longitudinal slot 37 of an inner cylinder 82 of the cutting head 50, this sliding taking place in the direction of the axis of symmetry 55. One end of the pin 43, which penetrates into the rod 34, passes through an elongated slot 44 formed in the frame 32, parallel to the axis of the rod 34; the pin 43 also passes through the housing 3 and constitutes, in this way, an indicator 31 which is visible from the outside and which indicates the instantaneous position of the rod 34, and consequently the position of the switching device 6 on the scale 15 (fig. 1). Because the end of the pin 43, constituting the indicator 31, is supported by the longitudinal faces of the elongated slot 44, the pin 43 also prevents the rod 34 from rotating when the screw drive 33 is actuated by the using button 9.

The length of the insulation 4, intended to be removed by the appliance 1, corresponds to the space between the cutting plane St of the cutting head 50 in the rest position (e.g. prior to the start of the work), and the face of the stop member 23 of the switching member 19 of the switching device 6, as shown more specifically in FIG. 18. By axially adjusting the rod 34 before the start of the operation, the control lever 36 moves the switching device 6 as a whole.

This movement takes place in the axial direction of the switching device 5, so that the space between the stop member 23 of the switching member 19 and the cutting plane S i of the cutting head 50 and therefore the length L of the insulation 4 to be removed can be changed within clearly defined limits, for example between 2 and 10 mm in the device io as described.

In fig. 18 and 19, the rod 34 is shown in the same axial position. However, it is easy to recognize that, in the assumption that the support 35 does not change position, the axial sliding of the free end 41 of the rod 34 to the right causes the lower end 40 of the control lever 36 to the left and vice versa. Because in the device described, the lever arms Z, on both sides of the pivot point constituted by the screw 97 of the control lever 36, have an identical length, the axial movement 20 of the rod 34 coincides with the change of length L of the section of insulation to be removed. The button 10 adjusts both the cutting head 50 and the clamping mandrel 51 to the diameters of the wire insulation 2.

The shaft 13 of the button 10 is connected by a screw drive 25130 (see fig. 8.9) comprising a member 130 fixed non-rotationally to the frame 32, and a screw shaft 132 fixed axially to the member 131, but not turning with the button 10. Lavis 132 extends through a thread made in a sliding block or slider 133, which can move forward and back in the directions C 30 and X, between a recess 136 in the walls 134, 135 which are parallel. Block 133 slides easily with a minimum of play in directions C and X (fig. 13).

The pinch head 51 is connected by connecting rods 137 (fig. 3,8,9 and 21) to the slide 133, as well as to the lever 35 75, by means of which the width of a passage 77 of the wire 2 can be adjusted (as described below), can be rotated by an angle ß (preferably ß = 5 °); (see fig. 21). The link 137 comprises a transverse rod 138, a vertical rod 140 and a transverse rod 111. The transverse rod 138 is mounted so as to rotate around the axis of a bolt 139 of the frame 32. The transverse rod 138 comprises a pin 141 mounted on the slide 133, and is also connected to the vertical rod 140 by a seal 142. The lower part of the vertical rod 140 • comprises a central slot receiving one end of the transverse rod 111. The transverse rod 111 is fitted with a pin 110 constituting a pivot. The ends of the pin 110 are housed in longitudinal slots 143 which extend in the direction of the longitudinal axis of the vertical rod 140 and are arranged in the region of the central slot of the vertical rod 140. The pin 110 is held in the upper position by a spring 144.

At the end of the slide 133 surrounding the pin 141, the transverse rod 138 is provided with a longitudinal slot 145 which extends in the longitudinal direction of the transverse rod 55 138, but is perpendicular to the axis of the drive screw 130. The pin 141 is supported by a longitudinal slot 145 without play in the directions C and X, but with the possibility of recoil in the direction of the transverse rod 138. The kinematics of the link 137 requires play, like that appears so directly in figs. 8 and 9.

When the slide 133 is in its upper position (fig. 8), the lever 75 of the pinch head 51 is adjusted to the maximum diameter of the insulator, by the link 137 (see fig. 21). However, if by the rotation of the button 10, the slider 133 is moved downwards (fig. 9), the vertical rod 140 lifts the pin or the pivot point 110 from the transverse rod 111. A roller 146, mounted at the middle of the transverse rod 114, is supported by the contour of the first pinch cam 91, of

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so that the transverse rod 111 pushes the lever 75 downwards (figs. 9 and 21). In this way, the pinch head 51 has been adjusted to the minimum diameter of the insulator.

It is possible to continuously adjust the device to the intermediate positions between the two extreme positions described above, and corresponding to any diameter of insulation.

The maximum diameter of the insulation can be adjusted by the rotary knob 10, while the transverse rod 111, on which the return spring 147 acts, is returned to its initial position.

The spring 144, which maintains the pin 110 in the upper position, serves to absorb the excessive loads which can be generated by means of the transverse rod 111, as a consequence of an unexpected increase in the thickness of the insulation.

The dimension of the space between the clamping jaws, for example the dimension of the passage 77, is indicated on the outside of the housing 3 on the scale 16, by means of an indicator 52 fixed to the slide 133 and passing through the frame. 32 and the housing 3.

The adjustment of the cutting head 50 to the desired diameter of a conductor is described below. Since the cutting head 50 and its components are described below, only the cooperation of the button 10 with the cutting head 50 is discussed briefly.

The cutting head 50 includes not only the interior cylinder 82 mentioned above, but also an exterior cylinder 80 which must be turned in the direction of arrow G, relative to the interior cylinder 82 which is stationary in the rest position of the device, when the cutting head 50 is adjusted to the maximum diameter of the conductor. The rotation is effected by the adjusting lever 81 which penetrates radially into the outer cylinder 80, through a bore (represented by FIGS. 4 and 13). The end of the lever projecting from the outer cylinder 80 passes through a cylinder 150 housed in a central position in the slider 133 and movable axially inside, for example in the direction of a parallel to the axis of symmetry 55.

The lever 81 crosses the slide 133 when the device 1 is viewed from the side (fig. 4) at a point different from that of the screw 132 of the screw drive 130. The screw drive 130 is located above of the plane of the cross section shown in FIG. 13 and therefore cannot be illustrated (see also fig. 11).

Fig. 13 shows the principles of adjustment of the cutting head 50 with respect to the diameter of the conductor. When the slider 133 is slid in the directions C and X, the lever 81 "rotates in the opposite direction clockwise around the axis of symmetry 55, in the direction of the arrow G, and drives the outer cylinder 80 (adjustment to the maximum conductor diameter). When the slider 133 is moved downward in the directions C and X, the lever 81 and, consequently, the outer cylinder 80, are turned clockwise around the axis of symmetry 55 (adjustment minimum conductor diameter).

These adjustments correspond to the adjustments of the pinch head 51. As mentioned above, these adjustments are indicated on the scale 16 by means of the indicator 52 of the slide 133.

The button 11 is used to adapt to an operating mode, in which the piece 4 of the insulation removed from the conductor 2 by the cutting head 50 is either entirely removed from the end of the conductor 2 and rejected as waste or removed over a certain distance from the cutting point, but left on the end of said conductor. This latter operating method is particularly suitable when wires with multi-strand conductors have to be preserved against the twisting of the fine strands constituting the conductor 2 after the insulation has been removed. For this purpose, the pivot point, around which a lever 105 controlled by the cam 93 rotates, is moved so that the thrust of the cam 93 is effective in one position (the section 4 is completely removed from the conductor 2), but is only partially gripped by the cam 93 in the other position (the section 4 is pushed back from the cutting point over a certain distance, but remains 5 in position on the conductor 2; see fig. 6,11 and 12).

The movable pivot point is constituted by an eccentric pin 104 mounted at the lower end of the shaft 14 of the button 11 and passing through one end of the lever 105 (see fig. 6 and 11). The other end of the lever 5 is fixed by means of a bolt 160 to the outer cylinder 80 of the cutting head 50 (fig. 24). By turning the knob 11 by 180 °, the pivot point of the lever 105 is moved by a distance F (fig. 12 shows the displacement of the pivot point shown on an enlarged scale which does not correspond to the effective distance F) . The particular position of the pivot point is indicated on the scale 17 by means of an indicator 53 placed on the edge of the button 11.

The pinch head 51 and then the cutting head 50 are now described in more detail.

The role of the pinching head 51 is to pinch the conductor 2 at the start of the operating cycle in a certain position and to maintain the conductor 2 in this position, until the cutting head 50 has cut the insulation 4. of the conductor 2 and removed the insulating section 4 either partially or completely from the end of the conductor. A new operating cycle, and consequently the action of the pinching head 51, are engaged by the end of the conductor 2, from which the insulation must be removed; this is done when the end is introduced into the opening 5 of the housing 3, that is to say when the trans-3o end makes the switching member 19, described above, in the switching position and therefore, predisposes the device 1 to the start of a new operational cycle.

As shown in fig. 21, the nipping head 51 is constituted by a rotary symmetry unit, which is mounted 35 in a housing 54 of rectangular section, this housing being fixed to the frame 32. The axis of symmetry 55 of the nipping head is coaxial with the opening 5 of the device 1. The housing 54 has a fixed front panel 56 provided with a bore 57 passing through the panel 56 and extending conically in the direction of the front side 40; the housing 54 also includes a rear panel 59 which covers the interior of the housing 54 and is fixed to the edge 58 of this housing, preferably by means of screws (see fig. 20). In the center of the rear panel 59 is a bore 60 aligned with the bore 57 of the front panel in the working position; the diameter of the bore 60 is substantially the same as that of the bore 57. On the inward-facing side of the housing 54, the rear panel 56 has a circular flange 61 standing towards the front panel 56, and concentric to the bore 60. The flange 61 has a cylindrical shoulder 62 so oriented in a radial direction, and a front face 63 oriented in an axial direction and perpendicular to the axis of symmetry 55. The pinch head 51 has a ring pinch 64 having a cylindrical inner face 65, the pinch ring 64 being disposed inside the housing 54, when it is in the working position. The axial dimension of the pinch ring 64 corresponds approximately to the height H of the flange 61. In operating mode, the inner face 65 of the pinch ring 64 bears sufficiently strongly against the shoulder 62 of the flange 61, so that the pinching ring 64 can be turned in the direction of arrow M around the flange 61 without play (fig. 21). The pinch ring 64 is blocked against axial movements by the flat inner surface of the rear panel 59 on the one hand, and on the other hand by a neck 66 which is provided with the housing 54. The flange 61 and 65 the ring pinch 64 preferably carry four bores 67 and 58 spaced by a distance K, and are distributed uniformly along the periphery of the ring 64, and aligned in the radial direction when they are in the working position. The dirty-

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wise 67 and 68 house the bolts 69 and 70 which are fixed in these bores and extend parallel to the axis of symmetry 55, in the direction of the front panel 56 of the housing 54. Each of the four pairs of bolts carries a pinch jaw 71 or 71a. In other words, each of the four clamping jaws 71,71a is provided with spaced bores 72,73 (spacing K), for the pairs of bolts 69,70. When comparing the diameters of the bolts 69.70 with those of the bores 72, 73, it will be noted that the latter have tolerances such that the bolts can be turned in the bores without play. One of the bores 72.73, in which are engaged the bolts 69.70 of each of the gripping jaws 71.71a, must have the shape of an elongated slot 164 extending in the direction of the central axis 100 of the gripping jaws 71.71a (fig. 21), the fact that during the operating cycle the spacing K of the bolts 69, 70 changes as described below.

When the pinch ring 64 is turned in the direction of the arrow M inside the housing 54, in the direction of the rear panel 59, the ends 74, facing the axis of symmetry 55, are turned in the direction of arrow N. The ends 74 of the clamping jaws 71, 71a can have the shape illustrated in FIG. 21.

According to the device described, the ends 74 overlap like the segments of a diaphragm or of a shutter of a photographic camera. As shown in fig. 21, the ends 74 can surround and retain a cylindrical body such as an electric wire 2 in a stationary position, provided that the pinch ring 64 is turned sufficiently in the direction of the arrow M. In this way, it is it is possible to remove the insulation from wires which only come out very weakly from circuit components. By rotation of the pinch ring 64 in the direction opposite to the arrow M, the pinch piece is released.

The pinch jaws 71 are distinct from the pinch jaws 71a, in that they have milled sections with opposite sides in the overlapping zones. The two pinch jaws 71 are the "left shapes" and the two pinch jaws 71a are the "right shapes". When the pinch head 51 has been mounted in the housing 54, the pinch jaws 71, 71a are housed in a single plane, as shown in FIG. 20.

At the gripping surface 76 which, in the gripping position, touches the insulation of the wire 2, the ends of the gripping jaws 71, 71a are provided with grooves which increase the gripping effect.

According to the diameter of the insulation of the wire to be stripped, a passage 77, intended for the insertion of the end of the conductor 2, is formed by the ends 74 of all the four clamping jaws 71,71a and adjusted by the button rotary 10. By the rotary button 10, it is possible to increase or reduce the size of the passage 77. The description which follows makes it possible to understand the transposition of the rotary movement of the button 10 on the clamping jaws 71, 71a of the pinch head 51.

A lever 75 is mounted on the pinch ring 64, passes through the housing 54 outward in a radial direction, and can be rotated by more than an angle X. The lever 75 is used to transfer the ring 64 from the position rest (loose), in the working position (pinch position) and to return it to its initial position (fig. 21).

The function of the cutting head 50 is to detach the section 4 from the end of the wire 2 from the insulating envelope surrounding the conductor, and to remove this section 4 either completely or partially from the conductor.

As shown in fig. 22 and 23, the cutting head 50 comprises an outer cylinder 80 with a lever 81 penetrating radially inside the cylinder 80, and used to adjust the cutting head 50 to the corresponding diameter of the insulator, an inner cylinder 82 supported rotatably by the outer cylinder 80, but locked axially with respect to it, and four knives, ie two knives 83 and two knives 83a. The knives 83 and 83a are fixed by a screw 84 to the outer cylinder 80 and by a screw 85,85a to the inner cylinder 82. One of the perforations, through which the screws 84,85,85a penetrate into each knife 83, must have the form of an elongated slot 165 extending towards the central axis of the knives 83,83a, because, during a working cycle, the space A between the screws 84, 85 / 85a changes, as decirt below.

The ends of the knives 83,83a have the shape of crescent edges 86,86a, arranged to overlap like the segments of a diaphragm or of a shutter of photographic camera, and leave a passage 87 of substantially circular section. In the rest position of the device 1, the dimension of the passage 87 is approximately that of the passage 77 of the pinch head 51 in its rest position.

The knives 83 and 83a are mounted in opposite pairs and overlap in pairs in the vicinity of the ends close to the axis of symmetry 55 of the cutting head 50. The two knives 83 constitute "the configuration on the left" and the knives 83a " the right configuration ", so that when they have been properly mounted on the cutting head 50, the edges 86,86a of the four knives 83,83a are always located in a single plane St and cut the insulation properly during a single transaction.

If, during a work cycle, the internal cylinder 81 is turned relative to the external cylinder 80 in the direction of the arrow W, the cutting edges 86,86a of the knives 83,83a perform a rotary movement indicated by the arrow W, during which the cutting head 50 is brought into its working position. During this operation, the cutting edges 86,86a of the four knives 83,83a reduce the dimension of the passage 37 by approximately the thickness of the insulation, to reach a diameter corresponding to the diameter of the stripped conductor. The cuts are made by the cutting edges, so that the cut section can be separated from the rest of the insulating envelope and partially or entirely removed from the conductor 2 by the displacement of the complete cutting head 50, this displacement being carried out axially. in the direction of arrow Q, while the head is held in the cutting position (fig. 22).

When the cutting head 50 has been adjusted to the maximum dimension of the passage 87, the back of one of the two knives 83a strikes the edge of one of the two screws 85, to limit the opening of the passage 87.

The section 4 of the insulation removed from the conductor can be rejected in the receptacle 8 arranged for this purpose, as indicated previously; the section 4 falls through the perforations 88, 89 and 90 provided for this purpose, both in the inner cylinder 82 and in the outer cylinder 80, as well as in the frame 32 of the housing (see fig. 5).

The insulation is removed as follows:

When a wire 2 is introduced through the opening 5 of the housing 3, through the passage 77 of the pinching head 51 and through the passage 87 of the cutting head 50, the end of the wire strikes the member stop 23 of the switching member 19 of the switching device 6, and closes the switch as described above with reference to FIG. 25. The motor 7 is engaged and drives the shaft 95 carrying the cams 91, 92, 93 and 94.

First of all, the switching cam 94 closes the limit switch 96, so that the motor 7 remains supplied even after the interruption of the contacts of the switching device 6 (FIGS. 17 and 26). Then, the cams 91, 92 and 93 become successively active and act in the manner indicated by the curves in FIGS. 27, 28 and 29.

By means of the pinch cam 91, the lever 75 is rotated by means of the transverse rod 111, and consequently

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the pinch ring 64 is turned relative to the housing 54 pivotally mounted inside the cylinder 82 of the of the pinch head 51 by a certain angle (preferably 4 °), cutting head 50, is moved in full with respect to the head so that the passage 77 of the pinch head 51 narrows, cuts 50 in the direction of arrow D, while the head of which holds the wire 2 in position (fig. 8 , 9.20 and 21). section 50 moves from distance E. The switching device

Simultaneously, the profile 108 of the cutting cam 92 lowers 5 tion 6 is displaced by the double distance 2E, as follows:

a tongue 155 disposed at the end of the flanking transverse member.

106 (figs. 7 and 14). The tongue 155 of the transverse member 106 When the cutting head is moved in the direction D the is constantly pressed against the profile 108 of this cam, along the axis of symmetry 55 (displacement of a distance E), the means of the spring 153 mounted between the frame 32 and the cross-lever member 81 and the cylinder 150, through which the lever 81 passes, and versai 106. The transverse member 106, which is also con- 10 which is mounted slidingly in the slider 133,

nected by screws 156 at the end of the inner cylinder 82 of the head are displaced by this same distance E (fig. 3 and 13). The cutting support 50, rotates in the opposite direction to the needles of a 35 is fixed to the face 162 of the cylinder 150, by means of a screw 163

shows, the inner cylinder 82 in the direction of arrow T passing through an elongated slot 128 (fig. 16), so that the cylinder

(fig. 23), and in this way brings the cutting head 50 into the dre 150 can be moved freely relative to the support 35,

cutting position described above. 15 when an adjustment according to the conductor cross section

The curve of the cam preferably used as produced by means of the button 10 in the directions C and X, but cutting cam 92 is illustrated in FIGS. 15 and 29. In addition, one so that the support 35 is carried along the internal thread axis 157 receives a headless screw 158, used for symmetry 55 in direction D, in the case of displacement attach the cutting cam 92. axial of the cylinder 150.

The withdrawal cam 93 presses on the lever 105 by means of a 20 When the cutting head 50 is moved to the right with a roller 161 attached to the lever 105 in the direction of the arrow D from its position illustrated in FIG. 18, and brought into the (see fig. 2,11 and 12). The consequence is that the outer cylinder of FIG. 19, the screw 97 inserted in the support 35 laughing 80, as well as the cutting head 50 in its entirety, are also displaced by the same distance E to the right, the screw 97 constitutes axially displaced in a direction parallel to the axis of the pivot of the lever 36. Because two lever arms arranged in metry 55, in the direction of the arrow D. The roller 161 on either side of the pivot has the same length Z, the lever end 105 is biased by the spring 154 mounted between 105 and the bottom 40 of the lever 36 moves to the right, from a frame 32, and constantly carries the withdrawal cam 93 (fig. 12). double tance, i.e. 2E (relative to stationary rod 38),

When the cutting head 50 is moved in the direction until it reaches the stop 129. The movement is amplified

axial, the knives 83, 83a remain in the closed, and trusted, position because the upper end 38 bears against the end

in this way (depending on the position of the button 11), the 30 mite 41 of the rod 34 which is stationary during operation-

section of detached insulation 4 is either completely removed or part of the device 1.

partially removed from the conductor, as previously described. Consequently, the stop member 23 of the communication member

To prevent damage to the conductor 2, the profile 108 of the position 19 of the switching device 6 is displaced by a

the cam 92 has a small shoulder 109 at 135 °, so tance 2E to the right, and pushes the insulating section 4 towards the that, when the cutting is finished, the passage 87 of the receptacle head 8, after that it has been removed from the conductor 2 by the cutter 50 is slightly increased (see fig. 23; fig. 15 and 29 with displacement of the cutter head 50. Thus, the cut plane Sj

135 °). As a result, the cutting edges 86,86a of the necks of the cutting head 50 have been moved towards the cutting plane S2 (fig.

83.83a ratings cannot damage the conductor. This 18 and 19).

characteristic also preserves the sharp edges 86 and It should be noted that by an appropriate shape of the housing 3,

86a. 40 device 1 is easily accessible for small repairs

The side 102 at 265 ° of the cam 92 opens the cutting head 50, and for service. It is particularly advantageous to provide that which closes briefly due to the side 103 in the position of easy removal of the front panel 151 from the housing 3, this characteristic

320 °. In this last position, any section of insulation which is teristic allowing easy access to the pinching head 51 and which, on the trajectory of the knives 83, 83a, is rejected by the (after the removal of the head 51) at the head of cut 50, like the cutting head. 45 shows fig. 10. The front panel 151 can be attached to the

In order to obtain sufficient space for the box section 3 by means of hinges, and to the support 32 by means

Lesson 4 can be removed, the switching device 6, which is a knurled screw 149.

VS

17 sheets of drawings

Claims (4)

635,469 1. An apparatus for stripping electrical wires to remove the insulation from the end of the conductor of an electrical wire, characterized in that it comprises: a housing having an opening in one of its walls to allow the introduction of a wire end intended to be stripped, said opening defining a reference axis; a clamping mandrel mounted inside said wall coaxial with said insertion opening, said mandrel having at least three jaws arranged so that the angles which separate them are equal, said jaws being arranged to open and close synchronously; a cutting head housed in said housing and comprising several knives arranged to be separated in order to define a rest position and to move towards each other in order to define a cutting position at a determined distance around a cutting axis which coincides with said reference axis; switching means arranged in said housing and a part of which intersects said reference axis, so that the end of said wire can engage said switching means when the wire is inserted into said opening and passes through said mandrel and said cutting head; motor means activated by the closure of said switching means; and control means driven by said motor means, performing an operational cycle during which said mandrel and said cutting head are engaged sequentially to pinch the stripping wire, to move said knives to the cutting position, to cut the insulation , to strip the conductor, to open the mandrel and return the cutting head to its rest position and finally to deactivate said motor. 2. Apparatus for stripping electrical wires according to claim 1, characterized in that said jaws of the clamping mandrel are arranged in a plane, said jaws having ends shaped to produce a circular pinching profile when the jaws are closed and are arranged so as to overlap circumferentially. 2 3 635,469 said axial movement, it comprises a connecting lever having a pivot point, activated by the control means. 14. An apparatus for stripping electrical wires according to claim 13, characterized in that the axial displacement of the cutting head is adjustable by the displacement of the pivot point of said connecting lever between the control means and the cutting head, l insulation then being only partially removed from said wire. 15. An apparatus for stripping electrical wires according to claim 14, characterized in that it comprises a shaft mounted in the casing of said apparatus and part of which stands outside the casing, said shaft comprising a pin disposed eccentrically to provide the pivot point to said link lever between the cutting head and the control means, said link lever being arranged to slide as well as to rotate around the pivot point, a button fixed to the protruding end of said shaft, and an indicator for showing the position of said button, the rotation of said shaft between two rest positions causing said pivot point to move along the link lever so that, in one of the positions, the lever arm is larger than in the other. 16. An apparatus for stripping electrical wires according to claim 10, characterized in that said cutting head has four knives also spaced apart and having curved cutting edges, the cutting edge of the two diametrically opposed knives overlapping circumferentially with the cutting edge of the other two diametrically opposite knives, the cutting edges of the respective pairs of knives being planarly sharpened along the covering surfaces, so that, when the inner tube is turned relative to the outer ring, the cutting edges overlap by closing like scissors around a passage of substantially circular cross section. 17. An apparatus for stripping electrical wires according to claim 1, characterized in that the cutting head is mounted so as to be movable along said reference axis, and in that said switching means comprise a tabular housing, a member a cylindrical switching device adapted to be able to slide partially inside said housing and having a contact surface at one end, a spring of low elasticity acting in an axial direction against said cylindrical switching member so as to push it out of said tubular housing, a contact rod embedded in an insulating body, said body being housed inside said tubular housing and said rod having a contact surface, at one end, made so as to cooperate with said contact surface of said switching member, and fixing means for fixing said contact rod in a given position inside said tubular housing, said switching member being fixed é, so as to remain inside the housing, by means of a transverse member passing through said cylindrical switching member and extending in one or more longitudinal slots arranged in said housing so that said switching member can slide inside a housing over a distance limited by the length of said slots, said switching means closing the contact, when said switching member is forced against the spring, so as to provide electrical continuity between said member switching and said contact rod. 18. An apparatus for stripping electrical wires according to claim 17, characterized in that the housing of the switching means is adjusted firmly inside the cutting head, so as to be able to slide axially along said reference axis without play. . 19. An apparatus for stripping electrical wires according to claim 18, characterized in that said switching means are connected to said cutting head by a lever having a fixed pivot, so that any axial movement of said cutting head, inside the apparatus, produces an axial displacement of switching means in the same direction, the distance of movement of said switching means being amplified by the leverage. 5 20. An apparatus for stripping electrical wires according to claim 19, characterized in that it comprises adjustment means for adjusting the length of the section of insulation intended to be removed. 21. Apparatus for stripping the electrical wires according to claim 20, characterized in that said adjustment means comprise a button mounted on the external surface of said housing and a spindle controlled by said button to be moved parallel to said reference axis , as a function of the amplitude of the rotation of said button, so that a change i5 in the position of the end of said spindle, which constitutes said pivot of said lever connecting said cutting head to said switching means, changes, correspondingly, the axial position of said switching means with respect to the cutting head making a corresponding change in the length of the section of insulation intended to be removed. 22. Apparatus for stripping electrical wires according to claim 1, characterized in that the cutting head is mounted so as to be able to move along said reference axis, and in that said control means comprise a shaft with 25 cams carrying several cams and driven by said motor means to carry out the operational cycle. 23. Apparatus for stripping electrical wires according to claim 22, characterized in that the control means comr take a cutting cam and a cutting arm, in that Said cutting head comprises an outer tube and an inner tube mounted in the first to be able to rotate, said knives being pivotally attached to the two tubes in such a way that the relative rotation of said tubes causes the knives to approach each other or to move apart in the direction of relative rotation, and in that the cutting arm is attached to the inner tube at one of its ends and rests on said cam at the opposite end, so that the rotation of the camshaft causes said cam to transfer said knives from said cutting head from said rest position to said cutting position, and subsequently causes said knives to return to said rest position, before the end of said operational cycle . 24. An apparatus for stripping electrical wires according to claim 23, characterized in that the cutting cam has a profile such 45 that, after the transfer of said knives to said cutting position, it partially opens said knives so that the opening obtained has a diameter greater than said cutting diameter but less than the diameter of the insulator, and retains the knives in this position until the insulation has been completely removed. 25. An apparatus for stripping electrical wires according to claim 23, characterized in that the profile of the cutting cam is such that said knives, after opening in their rest position, are partially closed and finally reopened in 55 their rest position after the wire has been completely stripped. 26. An apparatus for stripping electrical wires according to claim 22, characterized in that the control means comprise a movable cam and a stripping lever which is linked to Said cutting head to generate an axial displacement of said cutting head, said lever being driven by said movable cam so as to move, the cutting head along said reference axis, in the direction of the end of said electric wire, after the knives have closed to their cutting position and before the knives return to their rest position, so that the edges of said knives force the termination part of the insulation, which has been separated at the by means of knives, towards the end of said wire causing stripping 635,469 3. Apparatus for stripping electrical wires according to claim 2, characterized in that it comprises a housing for the mandrel and a pinching ring, in that each of the jaws of the clamping mandrel is pivotally mounted on the inner face of a wall of said housing and on said pinch ring, one of said pivots of each jaw comprising a pin which extends through a slot in said jaw thus allowing the jaw to slide relative to said pivot, and in that said nip end of each jaw has an inclined surface and a concave nip surface arranged in said inclined surface, so that the rotation of said nip ring, in one direction, causes said nip ends to move closer to said jaws the rotation of these jaws in the opposite direction. 4. Apparatus for stripping electrical wires according to claim 3, characterized in that said pinching ring comprises a lever, said lever being connected to connection means having a pivot point, these connection means being activated by said means of ordered. 5. An apparatus for stripping electrical wires according to claim 4, characterized in that the space between the gripping ends of said jaws is adjustable, the adjustment range defining the range of wire diameters from which the insulation can be removed, and in that the concave nip surface is a circular sector having a diameter of curvature corresponding to the average of the diameters of said range of wire diameters. 6. An apparatus for stripping electrical wires according to claim 5, characterized in that the spacing of the gripping ends of said jaws is adjustable by displacement of the pivot point of said connecting means. 7. Apparatus for stripping electrical wires according to claim 6, characterized in that it comprises a threaded shaft mounted on said housing, said threaded shaft having a non-threaded end which comes out of said housing, a button mounted on said protruding end of said shaft , a nut mounted on said shaft, a mandrel adjusting lever fixed to said nut and having a fixed pivot, a rod attached to said mandrel adjusting lever, said rod being connected to said connecting means so as to constitute said point of pivoting adjustable, and an indicator connected to said nut, the spacing between the nipping ends of said jaws being adjusted by the rotation of said knob so as to move said nut along said shaft, thereby displacing the pivot point of said connecting means , said indicator being calibrated to display the spacing of said jaws. 8. Apparatus for stripping electric wires according to claim 7, characterized in that the cutting diameter of said cutting head is adjustable, the degree of adjustment corresponding to the range of wire diameters provided for. 'remove the insulation, the adjustment being carried out by means connected to said nut. 9. Apparatus for stripping electric wires according to claim 20, characterized in that said mandrel comprises four jaws mounted so as to define a first pair of diametrically opposed jaws and a second pair of diametrically opposite jaws, arranged in such a way that the nip ends of said first pair are superimposed on the nip ends of said second pair, said second pair being positioned orthogonally to the first pair, and in that said first pair and said second pair are adjusted to slide the 'one on top of the other when the pinch ring is turned. 10. Apparatus for stripping electrical wires according to claim 1, characterized in that the cutting head comprises at least three knives arranged so that the angles which touch them. separate are equal around said reference axis and is mounted so as to be movable along said reference axis. 11. Apparatus for stripping electrical wires according to claim 10, characterized in that said cutting head comprises an outer ring movable in rotation, said ring being hampered in its rotation, and an inner tube adjusted to the inner diameter of said outer ring in such a way that it can rotate inside said ring, and in that each knife is constituted by an elongated element, having a cutting surface at one of its ends, pivotally mounted on said inner tube and having its other end pivotally attached to said ring, one of said pivots of each knife 45 comprising a pin which extends through a slot in said knife, thereby allowing the knife to slide relative to said pivot, and said knives working in a planar, the cutting surfaces having crescent-shaped edges and being arranged circumferentially so as to overlap to form a closed circular passage between said cutting surfaces, the rotation in one direction of said inner tube, with respect to said outer ring, causing said knives to approach by their rotation in the opposite direction. 12. Apparatus for stripping electrical wires according to the revendi-55 cation 11, characterized in that the cutting diameter of said knives is adjustable, the adjustment range defining the range of diameters of wires that can be stripped, said cutting diameter being determined by the rotation of said inner tube inside the outer ring by a fixed angle during the cutting operation, and said adjustment being effected by the rotation of said outer ring around said inner tube by an angle additional, prior to cutting. 13. Apparatus for stripping electrical wires according to CLAIM-65 cation 12, in which the stripping is obtained by an axial displacement of the cutting head, after the knives have been brought to said cutting diameter and while these knives remain substantially closed, characterized in that, to achieve 4 of the conductor insulation, the movable cam then causing said knives to return to their initial axial position, in which the cut was made.