GB2121594A

GB2121594A - A method of and apparatus for manufacturing an element of flat electric cable

Info

Publication number: GB2121594A
Application number: GB08308935A
Authority: GB
Inventors: Andre Viaud
Original assignee: Filotex SA
Current assignee: Filotex SA
Priority date: 1982-04-06
Filing date: 1983-03-31
Publication date: 1983-12-21
Also published as: BE896280A; CH651958A5; FR2524691B1; GB8308935D0; IT8367373A0; IT1158930B; FR2524691A1

Abstract

Method for manufacturing a unit of flat electric cable formed by conductors (1) side by side encapsulated between adhesive films (2, 3), comprising previously cut openings on either of the films to allow the connections of the conductors. The cutting of the edges of the adhesive films is carried out during manufacture before separating the band with three layers into units of a specific length by making the band pass through cutting means 41 parallel to the axis of passage and with spacing equal to the desired width. <IMAGE>

Description

SPECIFICATION A method of and apparatus for manufacturing an element of flat electric cable The present invention relates to a method of manufacturing an element of flat electric cable, of the type which is formed by a large number of conductors side by side, encapsulated between adhesive films in polymeric material, comprising previously cut openings on either of the adhesive films to allow connections of the conductors, in which:: a) from supply bobbins there is unwound, on the one hand, the conductors and, on the other hand, two adhesive films with a width greater than the desired width for the unit of flat cable; b) at least one of the adhesive films is perforated in places corresponding to the areas where the conductors have to be denuded; c) the adhesive films are caused to pass on both sides of the conductors between two pressing and possibly heating assembly rollers, d) the structure with three layers obtained in pieces is cut, e) the edges of the adhesive films are cut into the desired width. The invention extends furthermore to an apparatus for putting this method into practice.

It has already been proposed that units of flat electric cable be manufactured by such a method.

However, it has been noted that it was not possible to obtain units with a very constant width, more especially as the borders of the adhesive films become deformed when passing the pressing and possibly heating rollers or at the time of their subsequent cooling when it takes place, and as the deformations in width are generally unequal. This has therefore led to the necessity of cutting the borders of the units of cable again after their manufacture. This operation notably lengthens the time of manufacture of the units of flat cable.

The aim of the present invention is to remedy this disadvantage and to permit a more rapid manufacture of the units of flat cable, while maintaining their very uniform width.

In accordance with a first aspect of the present invention there is provided a method of manufacturing an element of flat electric cable which is formed by a large number of conductors which are arranged side by side and encapsulated between adhesive films, and which comprises previously cut openings in either of the adhesive films to allow connections of the conductors; wherein a) there is unwound from supply bobbins, on the one hand, the conductors and, on the other hand, two adhesive films having a width greater than the desired width for the element of flat cable, b) at least one of the adhesive films is perforated in places corresponding to the areas where the conductors are to be stipped, c) each adhesive film is caused to pass between a side of the conductors and an associated pressing roller to form a three layered structure; d) the three layered structure is caused to pass through cutting blades, parallel to the axis of passage of the structure and with spacing equal to the desired width of the element, thereby cutting the edges of the adhesive films into the desired width; and then e) cutting into separate elements the three layered structure of desired width.

Thus the method according to an embodiment of the invention provides for the cutting of the edges of the adhesive films to be carried out on the structure with three layers, which is obtained before it is cut into pieces, by making their assembly with the conductors pass through cutting blades parallel to the axis of their passage and with spacing equal to the desired width of the unit.

In accordance with a second aspect of the present invention, there is provided an apparatus for car rying out a method as hereinbefore described, comprising: supply bobbins for supplying the conductors and the adhesive films; punching means for perforating the adhesive films; two pressing rollers; a pulling capstan; a receiving roller; and two cutting blades for cutting the edges of the adhesive films, the blades being parallel to the axis of passage of the films, having a spacing equal to the desired width of the cable element, and being arranged along the passage of the three-layered structure before the pulling capstan.

The pressing rollers may also be heating rollers.

The punching means preferably comprises a first punching part of one of the adhesive films which is fixed and a punching part of the other adhesive film whose position is adjustable according to the position of the first.

Advantageously, the apparatus further comprises, in addition, a detector of the perforations of one of the films controlling the punching part of this film.

For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 represents in perspective the assembly of the conductors and of the adhesive films with the aid of pressing and heating rollers; Figure 2 represents a plan of a unit of flat cable provided with areas where the conductors are stripped; Figure 3 represents in elevation a unit of fiat cable having a connection clip; Figure 4 represents the equipment for manufacturing the units of flat cable; Figure 5 represents a plan of the cutting of the edges of the units of flat cable (view according to the arrow F5 of Figure 4); and Figure 6 represents in section, according to the axis VI-VI of Figure 5, a section of the flat cable with an area where the conductors are stripped.

In Figure 1 the flat conductors 1,which are meant to be assembled with the adhesive films 2 and 3, for example of polyester or polyimide are guided by a distributing roller 4. Previously cut perforations 5A, 5B can be seen on the film 2. The conductors and the adhesive films pass between the pressing and heating rollers 6,7 with adjustable spacing and temperature.

The ensemble 8 of the conductors and the adhesive films stuck one to the other, involving one perforation 14 of the film 2, then heads towards a cooling area which will be described in the following with reference to Figure 4.

In Figure 2 the unit of flat cable 10 comprises conductors 11 denuded on their two faces at its right end. The latter are completely denuded in 12 at their left end on their upper face as a result of a perforation of the upper plastic film. They are also completely denuded in the area 13. On the other hand, the perforations 14, 15 and 16 only allow some of the conductors to be denuded and thus permit selective connections.

In Figure 3 the unit of flat cable 10, the conductors of which are denuded at their right end in 17, is provided herewith a connection clip 18.

In the manufacturing apparatus, represented in Figure 4, the ensemble of the flat conductors 1 is supplied from bobbins 21 to 27. They are covered by the distributing rollers 28 and 4 to the pressing and heating rollers 6,7 with adjutable spacing and temperature. The adhesive film 2 is supplied from the bobbin 30 having tensioning apparatus of the film which is not represented. The film passes in the fixed punching unit 31, which perforates it at regular intervals in response to the signals of a detector 32 of the passage of the previous perforation, arranged below at the distance L from the unit 31, according to a specific programme. In other respects, the adhesive film 3 is supplied from the bobbin 33, also being provided with a tensioning apparatus of the film, which is not represented.The film 3 passes in the punching unit34which can be moved so asto permit the adjustment of the superposition of the punchings on the two films. If the unit of flat cable does not necessitate connections on one of its faces, the punching unit 34 is useless.

In other respects, there pass on the pressing and heating rollers 6 and 7, under the adhesive films, elastic supports 35, 36 unwound from the bobbins 37,38 and re-wound on the bobbins 37A, 38A.

Coming out of the pressing and heating rollers, the ensemble 8 of the conductors and of the adhesive films welded one to the other passes in the cooling apparatus 39 with air circulation. The flat cable formed is sent back by the diverting wheel 40 to the cutting apparatus 41 of the edges which will be described in greater detail in the following with reference to Figure 5. The cut edges are wound up and retrieved on a roller 42.

The flat cable then passes to the pulling capstan comprising the roller 43 and the driving belt 44 actuated by a driving shaft 45 and passing on the return-pulleys 46 and 47. The speed of pull can be adjusted by varying the speed of rotation of the shaft 45.

The flat cable is finally sotred on the receiving bobbin 48. It may then, according to the require ments, be unwound and cut off in units of the required length.

In Figure 5 the piece of cable represented compris es a lower film of width L1 and an upper film of width L2. The cutting apparatus formed by the fixed blades 50 and 51 separates the edges 52 and 53 so as to leave a flat cable of the final width L3.

Figure 6 represents the section according to the axis Vl-Vl of Figure 5 with the upper film 2, the lower film 3 and the denuded area 28.

Although the manufacturing apparatus which has just been described with reference to Figures 1,4 and 5 seems to be the preferred embodiment of this aspect of the invention, it will be understood that various modifications may be brought in to it without leaving its general framework, some of its parts being able to be replaced by other which would play the same technical role. In particular, the joining of the adhesive films could be realized without heating, the films receiving in that case a coating of an adhesive sticking in the cold. The punching of the openings of the films could be controlled by a temporized programme subject to the speed of advance of the films.

Claims

1. A method of manufacturing an element of flat electric cable which is formed by a large number of conductors which are arranged side by side and encapsulated between adhesive films, and which comprises previously cut openings in either of the adhesive films to allow connections of the conductors; wherein a) there is unwound from supply bobbins, on the one hand, the conductors and, on the other hand, two adhesive films having a width greater than the desired width for the element of flat cable, b) at least one of the adhesive films is perforated in places corresponding to the areas where the conductors are to be stripped, c) each adhesive film is caused to pass between a side of the conductors and an associated pressing roller to form a three layered structure; d) the three layered structure is caused to pass through cutting blades, parallel to the axis of passage of the structure and with spacing equal to the desired width of the element, thereby cutting the edges of the adhesive films into the desired width; and then e) cutting into separate elements the three layered structure of desired width.

2. A method according to claim 1, wherein the adhesive film comprises a polymeric material.

3. A method according to claim 1, wherein each pressing roller is also a heating roller.

4. An apparatus for carrying out a method according to any of claims 1 to 3, comprising: supply bobbins for supplying the conductors and the adhesive films; punching means for perforating the adhesive films; two pressing rollers; a pulling capstan; a receiving roller; and two cutting blades for cutting the edges of the adhesive films, the blades being parallel to the axis of passage of the films, having a spacing equal to the desired width of the cable element, and being arranged along the passage of the three-layered structure before the pulling capstan.

5. An apparatus according to claim 4, wherein the punching means comprises a punching part of one of the adhesive films which is fixed and a punching part of the other adhesive silm whose position is adjustable.

6. An apparatus according to claim 4 or 5, which further comprises a detector of the perforations of an adhesive film, controlling the punching part of the said film.

7. An apparatus according to any of claims 4 to 6, wherein the pressing roller is also a heating roller.

8. A method of manufacturing an element of flat cable, substantially as hereinbefore described with reference to the accompanying drawings.

9. An apparatus for manufacturing an element of flat cable, substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.