Abstract:
A method of automatically manufacturing cable harnesses, and an apparatus and assembly for implementing the method. The assembly includes a main conveyor capable of transporting wires by means of transfer clamps, a secondary conveyor capable of transporting unique transfer trays, themselves capable of receiving at least one component. Transfer trays are loaded into the secondary conveyor, where they pass through a component loading station for receiving components, then the trays travel to an insertion zone. The insertion zone includes a device for transferring the loaded trays from the secondary conveyor to the main conveyor, where the components receive the wire ends for forming the cable bundles. The formed bundles are then transferred away from the insertion zone by the main conveyor.

Description:
This application is a continuation of application Ser. No. 08/078,287 filed Jun. 22, 1993, now abandoned, in turn, a 371 of application Ser. No. PCT/FR91/01020 filed Dec. 17, 1991. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a method and apparatus for automatically manufacturing wiring harnesses. 
     Wiring harnesses are already used for fitting to numerous industrial or domestic electrical equipment, e.g. such as washing machines, cars, . . . 
     Wiring harnesses are made up of a plurality of electrically conductive wires which are held together by means of collars made of plastic or of adhesive tape, so as to form a set of electrical links ready for connection and fixing onto a support. Each of the wires is initially cut to the desired length, then stripped, and its ends may be crimped to a terminal or inserted in a component (connector, socket, . . . ) depending on the requirements. 
     Harness manufacturethen consists in bundling together the wires prepared in this way and in inserting their ends in components, after which the bundle formed in this way is held together by binding means such as a collar or adhesive tape. 
     Methods and apparatuses are already known for automatic manufacture of wires that are cut to desired lengths, stripped, and crimped, e.g. as in U.S. Pat. No. 4,877,228, which describes and claims clamps for the conveyor of an automatic wiring machine conveyor, the clamps being intended to hold one or more wires. Also known are methods and apparatus for mechanically crimping terminals on the ends of an electric wire, and for automatically connecting crimped connections on wires or on electrical components. 
     French Patent 2,607,653, of which this patent is based, describes and claims apparatus which includes a conveyor that connects a station where the components for manufacture of a harness are fed to an automatic insertion unit having two carriages that are movable in three directions. 
     Known methods and apparatuses possess numerous drawbacks. One known shortfall is that most machines are capable only of making simple harnesses that include very few connectors or components. 
     In addition, most machines generally use insertion tooling that is specific to each type of component and to each type of end to be inserted. 
     SUMMARY OF THE INVENTION 
     One of the objects of the present invention is to automatically manufacture portions of wiring to harnesses or entire wiring harnesses that have components of types that are very varied in their volume, their mass, their outside shape, and their type of connection. 
     Another object of the present invention is to manufacture machines that are easy to modify at low cost and which are able to adapt to changes in the types of components used, and to be able to adapt to harnesses that use varying numbers of different components. 
     Another object of the present invention is to provide a fully automated manufacture of wiring harnesses that require little or no manual handling of the components and tooling required for working on the components. 
     Still another object of the present invention is to be able to manufacture harnesses at a high rate, without changing tooling. 
     A final object of the present invention is to automatically manufacture wiring harnesses that enable ends of said wires to be inserted in angular positions distributed around a horizontal axis. 
     A solution to the above objects consists in providing an apparatus for manufacturing wiring harnesses comprising wires having ends that are to be inserted in recesses of components, the apparatus having at least one main conveyor capable of transporting said wires by means of transfer clamps attached to the conveyor and further including at least one secondary conveyor capable of transporting a plurality of transfer trays. Each of the trays is capable of receiving at least one of said components, and a portion of said secondary conveyor is situated in an insertion zone in which there is also situated a portion of said main conveyor. The apparatus of the present invention further includes at least one loading station along said secondary conveyor for automatically loading said components onto said transfer trays, and the loading station includes means for transferring said transfer trays from said secondary conveyor to said main conveyor. 
     Each station includes at least one loading support, at least one output pusher, at least one input pusher, and at least one component pusher, thereby making it possible to load said components automatically onto said transfer trays. 
     A plurality of transfer tray feed conveyors, preferably of the accumulation type, include a means for feeding said secondary conveyor with transfer trays that were previously disposed on said feed conveyors, and said means for transferring said transfer trays from said secondary conveyors to said main conveyor include at least one insertion support, which is capable of moving vertically along an axis ZZ 2 . 
     The main conveyor is a linear conveyor having a substantially horizontal longitudinal axis XX 1 , and said secondary conveyor is a linear conveyor having a substantially horizontal longitudinal axis YY 1  and said longitudinal axes XX 1  and YY 1  are substantially perpendicular to each other. The main conveyor and said secondary conveyor include respective cog belts that are capable of imparting motion to said transfer trays. 
     Each of said transfer trays includes a base having a bottom face provided with studs that are capable of co-operating with said main conveyor and with said secondary conveyor. The base is connected by means of a stand to a plate, and said transfer trays include at least one holding jig suitable for co-operating with at least one of said components, wherein the holding jig is fixed on said tray. The transfer trays also include means for securing said components against said holding jigs so that at least one of said components can be loaded onto said transfer tray by translational movement, parallel to the substantially horizontal plane of said plate. 
     The holding jigs include at least one thrust face wherein at least one of said faces of the components can be brought to bear against at least one of its faces, with said holding jigs including a means for applying pressure on at least one other face of each of said components such that said components can be secured and held on said transfer trays, wherein said pressure means preferably includes a spring means. 
     The studs on each transfer tray are spaced apart in the longitudinal direction at a longitudinal pitch E 1 , while studs are also spaced apart in the transverse direction at a transverse pitch E 2 . The longitudinal pitch is a multiple of the pitch E&#39; 1  of the cogs on said secondary conveyor, while said transverse pitch is a multiple of the pitch E&#39; 2  of the cogs on said main conveyor. 
     The orienting station for orienting said ends of said wires is situated along said main conveyor, and upstream from said insertion zone. It includes at least one orienting clamp, capable of rotating about an orienting axis YY 2  that is substantially perpendicular to said main conveyor. 
     Each of the transfer trays includes at least one temporary end support such that it is possible to fix one of said wire ends on said temporary end support, and said transfer trays being open on their front faces such that it is easy to insert said wire ends in said recesses for wires in the components previously loaded into said transfer tray. The transfer trays are also open at their rear faces so that it is easy to gain access to the rear ends of the conductor elements of the said previously loaded component. 
     A solution to the problem posed also consists in providing a method of manufacturing a wiring harness which utilizes the assembly described immediately above. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The numerous advantages provided by the invention will be better understood from the following description which references the accompartying drawings, wherein: 
     FIG. 1 is a diagrammatic plan view of a particular embodiment of an apparatus of the invention. 
     FIG. 2 is a front view of a component transfer tray. 
     FIG. 3 is a section view on III--III of FIG. 2. 
     FIG. 4 is a front view of another embodiment of a component transfer tray in accordance with the invention. 
     FIG. 5 is a section view showing a detail of the FIG. 4 transfer tray. 
     FIGS. 6a and 6b are fragmentary diagrammatic views respectively of the conveyors and of the contact studs of a transfer tray in accordance with the invention. 
     FIG. 7 is a side view of transfer means in accordance with the invention. 
     FIG. 8 is a longitudinal section through an end orienting device in accordance with the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 is a diagrammatic plan view showing the main components of apparatus of the invention for manufacturing wiring harnesses. The apparatus comprises a main conveyor 22 having an insertion zone 23 in which zone there may be in operation an insertion means 29 having one or more insertion clamps 16 that have jaws 28. The clamps 16 can move perpendicularly to the longitudinal axis XX 1  of said main conveyor, along an axis YY 1  by means of a carriage 17 traveling on a carriage support 18 that has an axis XX 2  which is parallel to said axes XX 1 . Said main conveyor 22 shown in the figure is a&#34;linear&#34; conveyor which includes transfer clamps 15 that move along the direction of the arrow designated S&#39; 1 . The upstream portion of said main conveyor from said insertion zone 23 is provided with said transfer clamps for displacing wires 9 1 , 9 2  along said displacement direction S&#39; 1  past stations such as conventional automatic crimping stations (not shown). According to the invention, the automatic manufacturing apparatus includes a secondary conveyor 7 which is preferably a linear conveyor disposed on the axis YY 1 , substantially perpendicular to said longitudinal axis XX 1  of said main conveyor. The secondary conveyor 7 includes a portion 7a which is situated in said insertion zone, which portion 7a defines one end of said secondary conveyor. It can be seen that two stations 13 1  and 13 2  are provided along said secondary conveyor 7 for automatically loading components onto said transfer trays 8. It can also be seen that feed conveyors (1, 2, 3) are provided in the proximity of the second end 7e of said secondary conveyor 7. 
     Advantageously, said feed conveyors (1, 2, 3) are smooth-belt accumulating conveyors provided at one of their ends with respective abutments 200 and on which reserves of transfer trays 8 are disposed, the transfer trays preferably being empty. It can be seen in the figure that said feed conveyor 1 is designed to receive a narrow type of transfer tray 8 1 , that said feed conveyor 2 is designed to receive another type of transfer tray 8 2  that is wider, and that said feed conveyor 3 is designed to receive yet another type of transfer tray 8 3 . Each of said feed conveyors 1, 2, 3 is normally fed with a reserve of identical transfer trays. It can be seen that automatic means are advantageously provided for transferring said transfer trays from each of said feed conveyors 1, 2, 3, to said secondary conveyor 7, which means are represented by pushers (4, 5, 6). Said pushers (4, 5, 6), which may be controlled by a central control device for the manufacturing apparatus, are each capable of transferring a respective transfer tray previously disposed on the corresponding feed conveyor (1, 2, 3) onto said secondary conveyor 7. It can be seen that on said secondary conveyor 7, three transfer trays (8 1 , 8 2 , 8 3 ) are shown. Said transfer trays 8 1  and 8 2  which are situated upstream from said automatic component loading stations 13 1  and 13 2  are preferably empty. In the special case of components that are very bulky or of components of very complex outside shape, it may be advantageous to load said components manually into one of the types of transfer trays 1, 2, or 3, and to place said transfer trays manually on one of the respective feed conveyors 1, 2, or 3. It should be understood that said transfer trays 8 1 , 8 2 , and 8 3  are capable of moving on said secondary conveyor in the direction of arrow S 2 , because said secondary conveyor is-also a cog belt type. It can be seen that on said automatic loading station 13 1 , one of said transfer trays 8 3  which has previously been conveyed by said secondary conveyor has arrived face to face through a loading support 14 1  and has been transferred from the second conveyor to said loading support 14 1  by a pusher 19B 1 . It can be seen that said transfer tray 8 3  has previously been provided with a first connector 12 2  from said loading station 13 2  and that said transfer tray is in the process of being loaded on said automatic loading station 13 1  with a second connector or component 12 1  by means of a component pusher 10 1  and a component guide 11 1 . Once said component 12 1  has been loaded onto said transfer tray 8 3 , through action of said pusher 10 1  operating along an axis YY 2  that is parallel to said axis YY 1 , the pusher 19A 1  of said automatic loading station can transfer said transfer tray 8 3  back onto said secondary conveyor 7. It could also be seen in this figure that each of said transfer trays includes a front face 8j and a rear face 8k, which front and rear faces are named relative to the forward travel direction of said secondary conveyor designated by arrow S 2 . At the end of said secondary conveyor 7, in said insertion zone 23, it can be seen that transfer means 20 are provided for transferring said transfer trays 8 from said secondary conveyor 7 to said main conveyor 22. Said transfer means 20 comprises in particular, a transfer support 21 suitable for moving along an axis ZZ 2  that is substantially vertical to horizontal axis XX 1 , or perpendicular to the plane of the figure. It can be seen that according to the invention, said secondary conveyor 7 delivers said transfer trays 8 to said transfer means comprising said transfer support 20 in such a manner that said front faces 8j of said transfer trays 8 are facing said insertion means 29; and in particular the said insertion clamp 16. On said automatic component loading stations 13 1 , 13 2 , said components 12 are loaded in such a manner that the face that is to receive said ends of said wires are situated at the front face of said transfer trays. It can be seen that a station 24 for orienting the ends 9a of said wires 9 1  and 9 2  is advantageously provided along said main conveyor 22 upstream from said insertion zone 23. Said end orienting station 24 is provided with an orienting clamp 38 capable of rotating about an axis YY 2 , which is perpendicular to the longitudinal axis XX 1  of said main conveyor 22 and substantially parallel to said axis YY 1 . This makes it possible to position the ends of said wires angularly in such a manner as to enable them to be inserted in said angular positions into recesses in said components situated on said transfer trays 8. On said main conveyor 22, downstream from the insertion zone 23, there can be seen transfer trays 8 4  and 8 5  which have previously been loaded with said components and which have been transferred from said secondary conveyor 7 onto which position said insertion which position said insertion means 29 have inserted wires 9 into the recesses of said components situated on said transfer trays 8, thereby building up a harness or a portion of a harness. After that, said transfer means 20 transfers said transfer trays 8 from said secondary conveyor to the insertion zone 22a of said main conveyor, and the main conveyor 22 can then convey said transfer trays 8 4  and 8 5  fitted with said wires 9 whose ends are inserted in said components 12 for the purpose of building up a harness 28 or a portion of a harness, towards a downstream zone of said main conveyor for storage or utilization. In an alternative embodiment of the said main conveyor, it is naturally possible to provide a first and separate upstream main conveyor 22, which delivers said wires provided with connections at their ends to said insertion zone 23, and a downstream and second main conveyor 22 2  for removing said transfer trays on which said components have been placed, and on which said ends of said wires have been inserted in order to make up said harnesses or portions of harnesses. 
     FIG. 2 is a front view showing one embodiment of a transfer tray 8 in accordance with the invention and which gets placed on said secondary conveyor 7. In this embodiment, it can be seen that said secondary conveyor is mainly constituted by a generally channel section member 7c providedwith a groove in which a toothed or cog belt 7b can slide, thereby enabling said transfer trays to be driven because of the special configuration of their bases. It can be seen that each of said transfer trays includes a base 8b whose bottom portion is provided with studs 8a that may be substantially trapazium-shape in section, which base 8b is surmounted by a column-shaped stand 8c connecting said base to a substantially horizontal plate 8d. Supporting templates or jigs 8f 1 , 8f 2 , 8f 3  are provided on said plate 8d and serve to hold respective components 12 in predetermined positions, each of components 12 having respective recesses 12a in their front faces in which male connections are found, and onto which female connections are to be inserted, for example, which female connections have previously been crimped onto the ends of wires. 
     FIG. 2 also shows that said studs 8a of said base 8b are spaced apart at a transverse pitch E 2  along a transverse axis XX 3 . Supporting jigs 8f 4  and 8f 5  can also be seen provided on said plate. Supporting jig 8f 3  includes means for applying pressure on a face 12d of said component 12, which pressure-applying means comprises a spring 8g that bears against said face 12d and that is received within and supported by a cap 8h fixed to said supporting jig 8f 3 . 
     In FIG. 3, which is a view taken along line III--III of FIG. 2, it can be seen that said component 12 stands on said plate 8d of said transfer tray and that said component includes conductor elements 12e, each having one end 12f opening out into said recesses 12a of each of said components 12 and an opposite end 12g opening out to the rear face 12i of said component. As shown in FIG. 2, it can be seen in FIG. 3 that the top face 12d of said component is in contact with said spring 8g held by said cap 8h fixed to said supporting jig 8f 3 . Said supporting jigs 8f 4  and 8f 5  are fixed respectively to said supporting jig 8f 3  and to said plate 8d, so as to prevent said component 12 moving relative to said transfer tray along the longitudinal axis YY 1  of said transfer tray. It can also be seen that said studs 8a of said transfer tray base 8b are substantially trapezium-shaped in section and are longitudinally spaced apart at a distance E 1 , and that said cogs 7b of said cog belt are longitudinally spaced apart at a distance E&#39; 1 , which is such that studs 8a are complementarily received between said cogs 7b. 
     In FIG. 4, there is seen another embodiment of the transfer tray 8 of the apparatus of the invention. It can be seen that said transfer tray 8 comprises a plate 8d which may be provided with a reference for positioning said transfer tray, which reference is embodied by a notch 8e. It can be seen that said plate surmounts a stand 8c which connects said plate to a base 8b provided with studs 8a. Above said tray there can be seen holding jigs 8f 1 , 8f 2 , and 8f 3 , said holding jig 8f being in the form of a bracket, said holding jig 8f 2  being in the form of an arch provided with a slot 8f 21 , and said holding jig 8f 3  being in the form of a vertical plate. As a result, said jigs 8f 1  and 8f 2  make it possible to position a component 12 of complex shape on said plate, with a portion 12b of the component projecting and being received in said slot 8f 2  provided in said holding jig 8f 21 . Said holding jigs 8f 1  and 8f 2  are designed specifically to receive said complex component as shown in FIG. 4. It can be seen that said holding jig 8f 1  is provided on its side and top faces with two bores 8i 1  and 8i 2  each receiving respective springs 8g and 8g that bear against two corresponding faces 12d 1  and 12d 2  of said component 12 so as to exert pressure on said faces of said component, each of said springs being held by a respective plug 8h 1  and 8h 2 . As a result, each of said springs 8g exert a force represented by arrows f 1  and f 2  respectively urging said component against faces 8f 20  and 8f 30  provided on said holding jigs 8f 2  and 8f 3  respectively, thereby securing said complex shaped component 12. It can also be seen that two other components 12 1  and 12 2  provided with recesses 12a containing male connections 12f can also be fixed on said holding jig 8f 3 . It can also be seen that a plurality of temporary, end supports 81 are provided on said holding jig 8f 3 . 
     In FIG. 4, said transfer tray 8 is shown in front view, such that the front face of said transfer tray corresponds with the front faces of said components 12 that have been loaded onto said transfer tray. 
     FIG. 5 is a section through an embodiment detail of said holding jig 8f, shown on said transfer tray 8 of FIG. 4. It can be seen that said holding jig 8f 3  is provided with temporary end supports 81 on which connections 9a can be installed, which connections are crimped to the ends of wires 9. 
     FIGS. 6a and 6b show a preferred embodiment of the apparatus of the invention, in which said main conveyor 22 is provided with a cog belt 22d whose cogs 22b are spaced apart along said longitudinal axis XX 1  of said main conveyor at a longitudinal distance E&#39; 2 , and similarly said secondary conveyor 7 is provided with a cog belt 7d whose cogs 7b are spaced apart along said longitudinal axis YY 1  of said secondary conveyor 7 at a distance E&#39; 1 . It can be seen, advantageously in FIG. 6b, that said base 8b of said transfer tray 8 is provided with studs 8a which are spaced apart at a transverse distance E 2  and that are spaced apart at a longitudinal distance E l . It can be seen that in this embodiment said transfer distance E 2  of said studs is equal to twice said distance E&#39; 2  of said cogs 22b of said cog belt 22d of said main conveyor 22, and that said longitudinal distance E 1  of said studs 8a is equal to said distance E&#39; 1  of said cogs 7b of said cog belt 7d of said secondary conveyor 7, as a result said transfer tray provided with said base 8b fitted with the studs 8a as shown in FIG. 6b can be driven by said studs 8a meshing with said cogs 7b of said cog belt 7d of said secondary conveyor 7 up to said transfer means 20, after which said transfer tray 8 can be transferred onto said main conveyor 22, said transfer tray then being driven by said studs 8a meshing with said cogs 22b of said cog belt 22d of said main conveyor 22. 
     FIG. 7 is a diagram showing transfer means 20 enabling said transfer trays 8 to be transferred from said secondary conveyor 7 (shown in part) to said main conveyor 22 (also shown in part). FIG. 7 shows that said secondary conveyor 7 which extends along said longitudinal axis YY 1  has conveyed said transfer trays 8 in the direction of arrow S 2 , which trays are provided with said connectors 12 and have reached said end 7a of said secondary conveyor, i.e. said ends situated in said insertion zone. It can be seen that said transfer means 20 for transferring said transfer trays from said secondary conveyor to said main conveyor includes a transfer support 21 which can move along a substantially vertical axis ZZ 2  through operation of displacement means 26 which is preferably a mechanical actuator that includes a stepper motor and a screw-and-nut assembly, and guide means 25. Said guide means and said drive means may be fixed, for example, to a work surface 270. Advantageously, said transfer support 21 may be provided with locking means 27 for locking said transfer tray 8 on said transfer support 21 so as to secure said transfer tray 8 on said transfer support and prevent it from moving. As a result, said transfer support can move along a vertical axis ZZ 2  so as to cause one of said recesses 12a of said component 12 on said transfer tray to coincide vertically with the position on said vertical axis ZZ 1  of said insertion clamp 16, which can then insert said end 9a of a wire 9 in said recess 12a. When said insertion means 29, including said insertion clamp 16, have inserted said ends of said wires in said component 12 situated on said transfer tray as held by said transfer support (with the help of vertical displacements of said transfer support 21), said locking means 27 are unlocked so as to enable said transfer tray to be transferred onto said main conveyor 22 provided with said cog belt 22d, with said transfer being provided by an ejector pusher 31 provided with a rod 30 capable of pushing said transfer tray 8, along arrow T, with said transfer tray subsequently being conveyed by said cog belt 22d which co-operates with said base 8b of said transfer tray through said studs 8a, as previously described. 
     FIG. 8 is a fragmentary section through a device 24 for orienting the ends of the wires. It can be seen that said device 24 for orienting the ends 9a of said wires 9 includes a clamp defined by two jaws 38, which are capable of grasping an end 9a, said clamp also being capable of rotating about said axis YY 2  under drive from a motor 44 which drives it via a pulley 43 and a belt 42. The figure also shows a support 48 for said clamp, which support 48 receives said clamp and is capable of rotating about said axis YY 2 , e.g. in ball bearings, thereby enabling said support 48 to rotate relative to a fixed support 46 which may be fixed to said work surface 270. 
     Advantageously, means 45 are provided for actuating said jaws 38 of said clamp so as to cause them to open or close, depending on requirements.