FR2525403A1 - Automatic conveyor mechanism for cutting and stripping wire sections - uses system of toothed belts to increase accuracy of wire length drawn and has articulated jaw mechanism to strip insulation - Google Patents

Abstract

The mechanism is part of a fully automatic and programmable sequence and runs on a conveyor carousel arrangement. Wire is drawn from a supply reel and passes between a set of toothed belts. A large belt is driven around pulley wheels by a smaller, internal belt whose teeth mesh with those on the inner surface of the first belt. The wire is pressed against the first belt by another belt which moves in the same plane. Loosely mounted rollers form a flexible support for the wire. The wire-stripping work station has an articulated pair of jaws armed with blades which pierce the insulation from opposite sides of the wire. The jaws are driven by a worm gear via an eccentrically mounted pin and disc. The jaw assembly is moved longitudinally along a slide bar by a stepping motor. The separation of the jaws and length of insulation removed from the wire can be varied.

Description

 Transfer machine for cutting wires into sections, fitting them with connection pieces.

 The present invention relates to a transfer machine for cutting wires into sections and equipping the extremities with connection pieces.

 There are known transfer machines comprising a transfer conveyor which moves step by step and which serves a series of stations or apparatuses which each automatically carry out a specific operation comprising the unwinding of wires wound on reels, the seotionning of the wires in sections of determined length, the stripping of the ends of the sections, the installation and crimping on these ends of electrical connection pieces, such as lugs, sockets, plugs, etc., the installation of insulating sleeves on the crimps, etc. ..

Such a transfer machine comprising a rotary transfer plate is described for example in the patent application
FR. 81 / 18.181 (Automatismes et Techniques Avancées - ATA ").

 The objective of the present invention is to provide improvements to known transfer machines, more particularly improvements relating to the unwinding of the wire by means which make it possible to measure, without risk of error, the lengths unwound and concerning the stripping of the ends of wire over lengths determined by a program, which may vary from one section of wire to the next.

 The machines according to the invention comprise, in a known manner, a station for unwinding the wires wound on reels, which station comprises a motor which drives a first toothed endless belt and means for pressing the wires against a straight strand of said belt. .

 According to a first improvement, the wire unwinding station includes a second notched endless belt which is located inside the first belt, which is applied against the internal face of said straight strand and whose notches are turned towards the outside. , so that the notches of the two belts mesh with each other.

 Advantageously, the reeling station includes a device for supporting the wires on the first belt comprising a third endless belt which is situated outside said first belt, on the side of said straight strand opposite to said second belt and which supports said wires against 1 external face of said rectilinear strand located in the zone where this strand meshes with the second belt.

 Each of the second and third belts passes over two idler pulleys mounted idly on their axis and over beds of rollers intermediate between said pulleys, which form two support planes parallel to said straight strand.

 A machine according to the invention comprises an apparatus for stripping the ends of the wires which comprises stripping spouts carried by two jaws which are articulated on a carriage sliding on slides parallel to the axis of the apparatus and it further comprises , a jack whose rod is moved parallel to the axis and carries a part on which are articulated two rods, each articulated on one of said jaws and said part carries an axis whose internal end carries an eccentric disc which is housed in a groove of said carriage parallel to said axis and the outer end of which carries an operating button and a lock nut making it possible to adjust the position of said eccentric disc, which determines the amplitude of the angular movements of said spouts.

 The mobile carriage carries a nut which is screwed onto a worm screw carrying a digital encoder which measures the stroke of said carriage and it further comprises means for blocking and unblocking said screw, which means is controlled automatically by a unit logic which, during each cycle, compares the stroke of said carriage measured by said encoder with a programmed value and which blocks said screw when this value is reached.

 The invention results in the automatic making of fully equipped sections of son.

 The wire unwinding device according to the invention makes it possible to drive the wire by a toothed belt which is made rigid and undeformable in the support zone, so that there is no sliding between the wire and the belt and it is possible to determine with great precision the length of unwound wire by programming the angular displacement of the toothed belt drive motor.

 The device for stripping the ends of wires according to the invention which includes a digital encoder of the carriage stroke and means for blocking this stroke> makes it possible to know, at any time, the exact position of the carriage and to stop it when this position corresponds to a programmed value, which therefore makes it possible to strip successive sections of wire on different lengths which correspond to the equipment which must be placed on these stripped ends and which are determined with very high precision.

 The following description refers to the appended drawings which represent, without any limiting nature, an example of embodiment of a transfer machine and of devices equipping it.

 Figure 1 is a schematic overview.

 Figure 2 is an elevational view of the wire feeder station.

 Figure 3 is a top view of Figure 2.

 Figure 4 is a section on IV-IV of Figure 1.

 Figure 5 is an elevational view of a stripping apparatus.

 FIG. 6 is a horizontal section along VI-VI of FIG. 5.

 There, FIG. 7 is a front view of FIG. 5.

 FIG. 8 is a view of the binary code written on the external face of the belt.

 Figure 1 shows schematically an overall plan view of a transfer machine which is intended to unwind wires 1a, 1b, wound on coils 2a, 2b, to cut them into sections of determined lengths, to strip the ends of these sections and to crimp on these ends electrical connection parts, such as lugs, sockets, plugs, etc.

all these operations being carried out automatically.

 The machine includes a transfer device which is for example a horizontal plate. 3 driven in step-by-step rotation by a geared motor group 4.

 At the periphery of the transfer plate are arranged various devices or modules which each perform a specific operation. A first module 5 simultaneously unwinds one or more wires and forms in them loops of determined length, which are held between the jaws of a pair of vises 6a, 6b carried by the periphery of the plate 3. The unwinding module 5 is tangent to the plate 3.

 The machine comprises a second module 7 which cuts the sections of wire between the loops. It then comprises a module 8 which strips the ends of the wires over a determined length, then modules 9> 10, etc., which lay and crimp a determined connection piece on each end of the wire and which isolate the crimping thereof. .

 A machine of this type is described in the application FR.

81 / 18.181 (Automation and Advanced Techniques - A.T.A.).

 The subject of the present invention is improvements to this type of transfer machine intended for cutting and automatically fitting sections of wire, it being specified that these improvements are not limited to a machine of the type described in the prior application FR. 81 / 18.181 but apply to any transfer machine comprising a wire unwinding station and a stripping station for the ends of the sections of wire situated along a transfer conveyor, whatever the circular or rectilinear shape of this conveyor transfer.

 it is also specified that the invention relates to machir.es-transfer which can unwind and equip either a single wire, or several separate wires, or flat wires comprising several conductors insulated by the same sheath.

 One of the problems to be solved in this type of machine is to accurately measure the lengths of wire unwound to obtain sections of determined length, given that such a machine must be able to cut lots comprising successive sections of different lengths which are programmed on the machine.

 The transfer machine described in the previous application No.

81 / 18.181 includes a wire unwinding station comprising a motor which drives a toothed belt which itself drives the wire, so that there is no slippage between the belt and the drive motor and determines the length of wire unwound from the rotation of the motor, for example in the case of a stepping motor, by programming the number of steps of the motor corresponding to the sections of successive wires which it is desired to obtain.

This way of measuring the length of the wire sections assumes that there is no slippage between the wires and the back of the toothed belt which drives them and that the belt does not undergo any bending in the drive zone.

 In the previous transfer machine, the wire was pressed against the back of a straight strand of the toothed belt by a pressure roller.

 The present invention relates to an improved device 5 for unwinding the wire intended to ensure the absolute straightness of the toothed belt in the zone where it drives the wires over a length of a few centimeters. In this way, it is guaranteed that the linear displacement of the belt in this area is strictly equal to the displacement of the original circumference of the belt drive pulley and can therefore be determined by programming the angular displacements of the pulley d 'training.

 Figures 2, 3 and 4 are enlarged views of a wire unwinding station 5 in an exemplary embodiment of a machine capable of simultaneously unwinding three wires 1a, 1b, 1c.

 On leaving the coils 2a, 2b, 2c which are not shown, the wires pass between rollers with guide grooves 11a, 11b, lic mounted idly on their axis.

 The unwinding of the threads is obtained by a traction exerted on the threads by a drive device for these, which at the same time makes it possible to determine the unwound length.

 This device comprises a toothed belt 12 which is driven by a toothed pulley 13, itself driven by a motor 14 which can be a stepping motor. The belt 12 passes over two return pulleys 15, 16 which determine a plane containing a rectilinear strand 12a of the belt which is horizontal in the case of the figure. The belt 12 is internally notched and its outer face is coated with a highly adherent material.

 The reeling device comprises a second endless toothed belt 17, which passes over two idler pulleys 18, mounted idly on their axis. The second belt 17 is located inside the first. It is notched outwardly and the notches have the same pitch as those of the belt 12. The second belt 17 is pressed against the internal face and notched of the straight strand 12a, so that the belt 17 is driven automatically by the friction of the belt 12 and that the notches of the two belts overlap one another, the two belts thus forming a thick rigid assembly which is difficult to deform.

 The second toothed belt 17 is kept applied against the internal face of the straight strand 12a by a bed of rollers which form a support plane parallel to the plane of the straight strand 12a.

 This bed of rollers is constituted by parallel axes 19a, 19b, 19n which are located inside the second belt in a plane parallel to that of the strand 12a and which are perpendicular to the direction of this strand. Each axis carries several rollers 20 whose radius is equal to the distance between the axis and the back of the belt 17. The rollers 20 mounted on one axis alternate with the rollers mounted on the neighboring axes, so that the back of the belt 17 presses on the upper generatrices of all the rollers which are staggered in the same support plane and that an upper face of the drive belt 12 is obtained which is perfectly flat and undeformable, in the zone against which the son la, Ib, lc are supported and are driven without gIillage.

 The rollers 20 or the axes 19 are idle and rotate when the second belt 17 is driven by the belt 12.

 The means for pressing the wires against the external face of the strand 12a are constituted by a third notched endless belt 21, the notches of which are directed towards the outside. The third belt is located outside of the drive belt 12, on the side of the strand 12a opposite to the second belt and it presses the wires la, lb, lc against a range of the external face of the strand 12a, located in the area where this strand meshes with the second belt and or the assembly of the two belts 12 and 17 forms a flat, rigid and slightly deformable bearing surface.

 The belt 21 can be a smooth belt. It is mounted on two crazy idler pulleys. The lower strand of the belt 21 is kept pressed against the strand 12a by a bed of rollers 22 mounted on axes 23 identical to the bed of rollers 20.

 It can be seen in FIG. 4 that the pressing device 21, 22, 23 is mounted in a U-shaped support 24 which is articulated by an axis 25 parallel to the wires la, lb, lc on a lever 26 articulated at 27 and pushed by a spring 28 which ensures the pressure of the wires. The articulation 25 makes it possible to obtain a uniform pressure of the wires on the drive belt regardless of the diameter and the number of wires.

 We see in Figures 2 and 3 a retractable roller 67 which is mounted on an articulated parallelogram 68 actuated by a jack 69 which moves the roller 67 perpendicular; ft has the direction of the wires leaving the reeling station.

 When the roller 67 is engaged, it forces the wires to form a loop. The roller 67 is wide enough that several wires 1a, 1b, 1c can be unwound simultaneously, each forming a loop.

 Figures 5, 6 and 7 show elevational views in horizontal section and from the front, of an apparatus 8 intended to strip the ends of one or more sections of wires which are presented parallel to the axis x xl of the apparatus by a transfer device for example by a rotary plate 3 equipped with pairs of vices 6a, 6b and cams which rotate the vices by a quarter of a turn to present the ends of the wires radially.

 FIG. 5 shows a vice 6 holding a piece of bare wire over a length d.

 An apparatus according to the invention is designed to automatically perform stripping or pre-stripping, that is to say a total removal of a determined length of insulating sheath or a displacement of this sheath exposing a length of wire located behind the end.

 The device can be programmed to perform stripping or pre-stripping on lengths of the various ends of the wire it successively processes, which may vary from one wire to another depending on the nature of the equipment to be placed on the wire. .

 The apparatus comprises two stripping spouts 30a, 30b mounted on a sliding carriage 31. The stroke of the carriage is determined for each cycle by the combination of a means capable of stopping the carriage 31 at any point of its stroke > an absolute digital sensor permanently indicating the position of the carriage or the spouts and a logic unit which compares the measurement supplied by the sensor to a programmed value and which controls the mechanism for stopping the carriage when this value is reached .

 We see in Figure 5 that the frame 32 of the device carries two horizontal guides 33a, 33b parallel to the axis x xl, between which the carriage 31 slides parallel to the axis x xl.

 The carriage 31 carries two jaws 35a, 35b which are articulated to the carriage by the axes 36a, 36b. Each of the jaws carries, at the front end, a spout 30a, 30b. The width of the spouts is such that the device can strip several wires simultaneously, for example three wires la. Ib, lc as shown in Figure 6.

The ends of the spouts 30a, 30b are cut in a bevel so that these spouts cut the insulating sheaths of the wires. Two links 37a, 37b are articulated on the rear ends of the two jaws by joints 38a, 38b. The two links are hinged together by an articulation 39 which is carried by a part 40 fixed to the end of the rod 41 of a jack 42. The part 40 carries an axis 43 whose internal end penetrates into a groove 44 cut in the carriage 31 parallel to the axis x xl. This end is equipped with a disc 45 which is eccentric relative to the axis 43.

 The axis 43 carries at its outer end a button 46 which makes it possible to pivot the eccentric 45. A lock nut 47 makes it possible to block the eccentric in a determined position.

 The difference between the length of the groove 44 and the horizontal diameter of the eccentric 45 makes it possible to vary the angular movement of the jaws 35a, 35b and therefore to adjust the closure of the spouts 30a, 30b.

 The jack 42 fulfills a double function. it moves the carriage 31 parallel to the axis x xl and it controls the closing of the spouts 30a, 30b.

 The operation during a cycle is as follows.

 We start from the position shown in Figure 1 where the carriage 31 is in front abutment and the stripping spouts 30a, 30b are open.

 The recoil of the jack 42 which drives the part 40 and the axis 39 is controlled, which causes the rotation of the links 37a, 37b and the closure of the spouts 30a, 30b on the insulating sheaths until the eccentric 45 comes abut against the rear end of the groove 44. This stroke has been adjusted as a function of the diameter of the conductors so that the closure of the spouts stops before they risk entering the conductors.

 The cylinder 42 continues to move back and the ltexcentric support 45 against the bottom of the groove 44 causes the carriage 31 to be driven in translation. The spouts 30a, 30b slide along the wires, stripping them over a length which is determined by the stroke of the carriage by means which will be described below.

 When the stripping or the pre-stripping is finished, the movement of the jack 42 which has a double effect is reversed. The eccentric 45 begins to move freely in the groove 44 which causes the opening of the spouts. When the eccentric 45 comes into abutment against the front end of the groove 44, it drives with it the carriage 31 and the open spouts advance to come back to the position of FIG. 1. The transfer plate 3 then advances by one not to evacuate the stripped wires and to present new wires to the stripping device and a new cycle begins again.

 The stroke of the carriage 31 determines the stripping length. The carriage 31 carries a nut 47 integral with the carriage which is screwed onto a reversible endless screw 48 parallel to the axis x xl, so that the translational displacements of the carriage cause the screw to rotate in one direction or the other. . The worm gear 48 is extended by an axis 49 mounted in a rolling bearing 50. The rear end of the axis carries a toothed pulley 51, over which passes a toothed belt 52 which transmits the movement to a second toothed pulley 53 mounted on a second axis 54 parallel to the x xl axis.

 The axis 54 is equipped with an e-brake servo 55 which is controlled by the logic unit and which blocks or releases the screw 48 which makes it possible to control the movement of the carriage 31.

 According to a variant shown in the figures, the screw 48 is irreversible, so that the movement of the carriage cannot cause the screw to rotate. In this case, the electric brake 55 is replaced by a two-way motor 56, which may or may not be associated with an electric brake 55.

 Starting the motor 56 drives the screw 48 in one direction or the other. In this case, it is therefore the control by the logic unit of the motor 58 which makes it possible to control the stroke of the carriage which is normally blocked by the nut 47.

 The stripping apparatus is equipped with a sensor of the rotation movement of the rod 41 which makes it possible to know the stroke of the carriage 31. In the example shown, the toothed belt 52 serves at the same time as a transmission belt for the flouvenent by its notched internal face and absolute coding track by its external face.

 The encoder comprises a row of photoelectric reflection sensors 57, which are arranged transversely to the belt 52, each sensor reading a track from the belt.

 FIG. 8 represents a view of the external face of the belt in an embodiment where it is divided into eight longitudinal tracks. The external face of the belt has an absolute coding of the travel of the carriage which is for example a normal binary code with eight bits. Of course the binary code can be replaced by any other code such as a decimal binary code, a Gray code, a bar code etc ...

 Similarly the photoelectric reflection sensors can be replaced by other sensors such as proximity sensors, microswitches, magnetic sensors or a photoelectric receiver associated with a transmitter which emits a beam which scans the width of the belt 52.

 FIG. 8 represents a preferred embodiment in which each cross section of the belt which corresponds to a well-determined position of the carriage carries eight binary signs having very different reflecting powers, for example white spots and black or colored spots.

 Advantageously according to the example shown, the belt 52 is notched on its two faces and the teeth of the external face are subdivided into eight sections, some of which are removed and constitute the "O" of the binary code while the others are preserved and painted in light color and constitute the "1" of the binary code which are represented in hatching in figure 8.

 When each tooth on the external face passes under the row of sensors 57, these emit a combination of signals which expresses in binary code, readable directly by the logic unit, the position of the carriage.

 For each cycle of the device 8, a comparison module compares this binary value with a programmed value and automatically controls the closing of the electrobrake 55 and / or the stopping of the motor 56 to stop the carriage when the value progresses; lmmée is reached.

 We thus realized an absolute encoder with gear reduction Zu movement since each notch of the belt is equivalent to a stroke of the carriage equal to p / n, p being ie pitch of the screw 48 and n the number of teeth of the pulley 51, which allows you to adjust the stripping length d with very high precision of the order of 0.1 mm.

 The stripping apparatus 8 according to FIGS. 5 to 7 comprises two vice jaws 58a, 58b, in the form of a yoke with two branches. Each jaw is articulated to the frame by two axes 58a for the upper jaw and 58b for the lower jaw and carries a transverse bar 60a, 60b at the front end. When the jaws are closed, the bars 60a, 60b pinch the wires and hold them during stripping in order to avoid that the wires risk being torn from the vices 6.

 The jack body 42 is fixed on a plate 61 which carries two rods 62a, 62b each articulated to a jaw by a joint 63a, 63b.

 The two m2 jaws 58a, 58b each carry a toothed sector 65a, 65b dot the teeth mesh with each other to ensure the symmetry of the movements of the jaws. The body of the jack 42 is mounted on rods 64a, 64b which slide in a fixed support 66.

 When the jack pulls on the carriage to make it move back, the reaction advances the jack body 42 which moves the rods 62a, 62b, which causes the vice 60a, 60b to close, synchronized with the recoil stroke of the carriage. Conversely, the vice 60a, 60b opens when the carriage 31 advances.

 Springs 65 are interposed between the rods 62a, 62b and the jaws 58a, 58b to limit the pressure exerted by the vice on the wires in order to avoid crushing of the latter.

Claims (9)

SELL i CATI ON S 1. Transfer machine for cutting wires into sections and equipping them with connection pieces, comprising a station (5) for unwinding the wires (la, lb) and a transfer mechanism (3) which presents the wires in front of devices (7, 8, 9, 10) which cut them, which strip the ends and equip them, which deposition station (5) comprises a motor (13) which drives a first toothed belt (12) and means to support the wires (la, lb, lc) against a straight strand (12a) of said belt, characterized in that said unwinding station (5) comprises a second belt s ;; tns fine notched (17) which is located the interior of the first belt, which is applied against the internal face of said rectilinear strand (12a) and the notches of which face outwards, so that the notches of the two belts mesh with each other.  2. Machine according to claim 1, characterized in that the reeling station comprises a device for supporting the wires on the first belt comprising a third endless belt (21), which is located outside of said first belt, on the side of said rectilinear strand (12a) opposite said second belt (17) and which supports said wires (la, lb, 1c) against the external face of said rectilinear strand (12a) situated in the zone where this strand meshes with the second belt  3. Machine according to any one of claims 1 and 2, characterized in that each of said second and third belts t17, 21) passes over two deflection pulleys (18) mounted idly on their axis and on rollers beds (20 , 22) intermediate between said pulleys, which form two support planes parallel to said straight strand.  4. Machine according to claim 3, characterized in that each of said roller beds is constituted by axes (19, 23) parallel, which are located in a plane parallel to said straight strand (12a) and which are perpendicular to said straight strand and by identical rollers (20, 22) which are mounted on said axes and whose radius is equal to the distance between said axes and the back of the toothed belt (1 !, 21), against which they are supported and the rollers mounted on an axis alternate with the rollers mounted on neighboring axes.  5. Machine according to claim 2, characterized in that said supporting device is carried by a support (24) which is mounted on a hinge pin (25) parallel to the direction of the wires.  6. Transfer machine according to any one of claims 1 to 5, comprising an apparatus (8) for stripping the ends of the wires, characterized in that said apparatus comprises two stripping nozzles (30n, 30b), carried by two jaws (35a, 35b), which are articulated on a carriage (31) sliding on slides (33a, 33b) parallel to the air (x xl) of the device and it is carried, besides a jack (42) the rod (41) of which is moved parallel to the axis (x xl) and carries a part (40) on which are articulated two connecting rods (37a, 37b) each articulated on one of said axes (35a, 35b ) and said part (40) carries an axis (43) the internal end of which carries an eccentric disc (45) which is housed in a groove (44) of said carriage parallel to said axis and the external end of which carries an operating button (46) and a lock nut (47) allowing the position of said eccentric disc (45) to be adjusted, which determines the amplitude of the angular movements of said spouts (30a, 30b).  7. Transfer machine according to claim 6, characterized in that said carriage (31) carries a nut (47) which is screwed onto a worm (48) carrying a digital encoder (57) which measures the stroke of said carriage and it further comprises a means for blocking and unblocking said screw (48), which means is automatically controlled by a logic unit which, during each cycle, compares the stroke of said carriage measured by said encoder with a programmed value and which blocks said screw when this value is reached.  8. Machine according to claim 7, characterized in that said endless screw (48) is reversible and the means for blocking the screw is an electric brake (55).  9. Machine according to claim 7, characterized in that said endless screw (48) is irreversible and is rotated by a two-way motor (56).  10. Machine according to any one of claims 7 to 9, characterized in that said worm (48) carries a toothed pulley (51) over which passes a toothed belt (52) driving a second toothed pulley (53) mounted on an axis (54) carrying said electrobrake (55) or being driven by a motor (56) in the case where said screw (58) is irreversible and said encoder is constituted by a code inscribed on the external face of said belt and by a row of sensors (57) arranged transversely to said belt which read said code.  he. Machine according to claim 10, characterized in that said toothed belt (52) is notched on its two faces and the notches of the external face are divided into n sections, some of which are removed and constitute the binary "O" and others, which are kept, are painted in a light color to constitute binary "1". and said sensor (57) is coogged by a row ~ transverse of n photoelectric reflection sensors.  12. Machine according to any one of claims 6 to 11, characterized in that said stripping device (8) comprises a wire clamping vice (6Oa, 60b) comprising two jaws (58a, 58b) articulated to the frame and connected by two rods (62a, 62b) to the cylinder (42) of the jack, which can slide parallel to the axis (x xl).