IES65038B2 - Method of affixing connectors to a ribbon cable and apparatus for use in such a method - Google Patents

Abstract

A method of affixing connectors (17,18) to a ribbon cable (16), comprising the steps of: positioning a ribbon cable (16) onto a ribbed surface (11) of a jig base (10) and over a connector cap (17) positioned in a recess (12) provided in a surface of jig base (10) adjacent to the ribbed surface (11); placing a connector base (18) onto said cable (16) above said connector cap (17); and providing a controlled vertical downward pressure onto said connector cap (17) and removing said pressure when said connector base (18) has travelled downwards by a sufficient distance to mate with said connector cap (17). The method and apparatus ensure that all components are held steady thereby eliminating lateral movements which result in unaligned connectors, reject cables and breakages. The apparatus allows improved efficiency and accuracy.

Description

Method of affixing connectors to a ribbon cable and apparatus for use in such a method This invention relates to methods of affixing connectors to cables.

Ribbon cables are used for sending signals between two electronic devices. Such cables comprise a flattened elongated flexible plastics body in which a plurality of electrically conductive wires are accommodated parallel to, but isolated from one another. The cables have a ribbed surface, each rib corresponding to one of the parallel wires. The cables can be connected to an electronic device by means of a connector which is adapted to plug into an input/output port of the device. Typically such a connector comprises a base and a cap which can be affixed together with the cable therebetween. One of these parts, for example the base, is adapted to plug into the device by means of a number of discrete electrical contacts in the form of sockets or pins. Each socket or pin corresponds to one of the wires with which it communicates electrically by means of a needle or tooth which penetrates through the wire when the base and the cap are affixed together to the cable.

Conventionally, the end of the cable is positioned against the cap and the base is snapped into place such that the needles penetrate the wires to make a good electrical contact. Problems can arise if the base is not properly aligned on the cable (in which case a needle may not correctly penetrate the wire for which it is intended) or if an excessive force is used in clipping the base and cap together onto the cable, in which case breakages will occur.

Additional problems arise if one tries to affix a connector to a cable having separated strands, for example if one wishes to change the order of the wires in a split and twist assembly or if one wishes to use two half-width cables side by side in a full-width connector. In such cases, it is very difficult to correctly align the individual sets of strands to ensure that a good connection is made by all of the pins $65038 simultaneously when the base is affixed to the cap, because the base and cap connect with a snap action, so the needles cannot be slowly pushed into the wires, rather they penetrate instantaneously.

In all cases, if there is any lateral movement when the base and cap are being affixed together (i.e at the crimping stage), reject cables will ensue.

The invention seeks to provide a method of affixing connectors to ribbon cables which is more reliable and more efficient than the prior art methods, and also to provide an apparatus for use in such a method.

Accordingly, the invention provides a method of affixing connectors to a ribbon cable comprising the steps of: (a) positioning a ribbon cable onto a ribbed surface of a jig base and over a connector cap positioned in a recess provided in a surface of the jig base adjacent to the ribbed surface; (b) placing a connector base onto said cable above said connector cap; and (c) providing a controlled vertical downward pressure onto said connector cap and removing said pressure when said connector base has travelled downwards by a sufficient distance to mate with said connector cap.

According to the process, all of the components are held steady while the connector base is controllably pressed onto the cable and cap. The measured downward pressure reduces the chances of breakages occurring and eliminates any lateral movement of the base or cap.

Preferably, step (b) comprises pushing an end of the cable against an abutment provided adjacent to the recess and thereby aligning the end of the cable with an edge of the connector cap.

This allows the production of a cable having a connector fitted thereto without the requirement of any further trimming to remove any loose end projecting beyond the connector cap. It also ensures that the edge of the cable does not stop short of the edge of the connector cap. The combination of the ribbed surface and the abutment ensure precise positioning of the ribbon cable in relation to the connector cap (which is situated in the recess), thereby ensuring accurate affixing of the connector to the cable. The relative positioning of the cap and cable can be critical, since the diameter of wires used in ribbon cables may be typically of the order of a few hundred microns.

According to the invention there is also provided an apparatus for use in the above method, comprising a jig base having a ribbed surface adapted to receive a ribbon cable, a recess in the jig base adjacent to the ribbed surface for receiving a connector cap and means for pressing a base of a connector vertically downwards towards the recess using a measured pressure over a predetermined distance.

This apparatus allows the method described above to be carried out reliably, efficiently and quickly.

Suitably, a wall of the recess is raised above the ribbed surface to provide an abutment for the ribbon cable.

The ribbon can be placed onto the ribbed base which is adapted to receive the ribbon in its correct alignment, and can then be pushed forward to overlie the connector cap and abut against the raised wall.

According to a preferred embodiment, the means for providing a measured vertical downward pressure comprises a hydraulically or pneumatically operated press plate.

The invention will be further illustrated by the following description of an embodiment thereof, with reference to the accompanying drawings, in which: Fig. 1 is a plan view of a jig base forming part of an apparatus according to the invention; Fig. 2 is a sectional side elevation of the base of Fig. 1, in use, taken along the line II-II; Fig. 3 is a sectional elevation of the cable and connector cap and base shown in Fig. 2, taken along the line III-III; and Fig. 4 is a front elevation of an apparatus according to the invention incorporating the jig base of Figs. 1 and 2.

In Fig. 1, a jig base is illustrated, generally at 10, for use in accordance with the invention. A ribbed surface 11 is provided on the jig base. The depressions in the ribbed surface are adapted to receive the ribs of a ribbon cable which can be laid flat on surface 11.

A recess 12 is adapted to receive the cap of a connector. A raised plate 13 on the side of recess 12 opposite ribbed surface 11 is elevated to provide an abutment against which the ribbon cable will stop. A pair of guides 14,15 define the sides of ribbed surface 11 and are used to position the ribbon cable correctly on that surface.

Referring additionally to Fig. 2, which shows the jig base 10 of Fig. 1, in use, one can see a ribbon cable 16 lying on ribbed surface 11 and overlying a connector cap 17 fitted into recess 12. Cable 16 abuts against raised portion 13 and the side of cable 16 abuts against guide 14. A connector base 18 provided with a set of teeth 19 can be pressed onto connector cap 17 such that teeth 19 penetrate ribbon 16 and make electrical contact with the wires therein. Ribbed surface 11, recess 12, abutment 13 and guide 14 (together with guide 15, as shown in Fig. 1) hold the components in position during the operation.

Fig. 3 illustrates the configuration of ribbon cable 16, connector cap 17 and connector base 18 before assembly. When base 18 is pressed onto cap 17, teeth 19 penetrate cable 16 to make contact with the wires therein.

In Fig. 4, the means for providing measured downward pressure onto connector base 18 are shown. Fig. 4 illustrates the complete apparatus, comprising the base 10 and the press plate mechanism, indicated generally at 20. A top plate 21 is supported above the jig base 10 by pillars 22. Top plate 21 in turn supports a pneumatic piston and cylinder arrangement 23, which reciprocates a press plate 24 along the path illustrated by arrow 25. A guide rod 26, upon which press plate 24 runs, ensures that the movement of press plate 24 is vertical and that no lateral movement occurs when connector base 18 is pressed onto connector cap 17 in the direction of the arrow shown in Fig. 2.

Accordingly, the apparatus is designed to automate the process in accordance with the invention and to provide a consistent method of attaching connectors to ribbon cables reliably and efficiently.

Claims (5)

1. Claims:1. A method of affixing connectors to a ribbon cable comprising the steps of: (a) positioning a ribbon cable onto a ribbed surface of a jig 5 base and over a connector cap positioned in a recess provided in a surface of the jig base adjacent to the ribbed surface; (b) placing a connector base onto said cable above said connector cap; and (c) providing a controlled vertical downward pressure onto said connector cap and removing said pressure when said connector base has travelled downwards by a sufficient distance to mate with said connector cap.

2. A method according to Claim 1, wherein step (a) 15 comprises pushing an end of the cable against an abutment provided adjacent to the recess and thereby aligning the end of the cable with an edge of the connector cap.

3. Apparatus for use in the method of Claim 1 or 2, comprising a jig base having a ribbed surface adapted to receive a 20 ribbon cable, a recess in the jig base adjacent to the ribbed surface for receiving a connector cap and means for pressing a base of a connector vertically downwards towards the recess using a measured pressure over a predetermined distance.

4. Apparatus according to Claim 3, wherein a wall of the 25 recess is raised above the ribbed surface to provide an abutment for the ribbon cable.

5. Apparatus according to Claim 3 or 4, wherein the means for providing a measured vertical downward pressure comprises a hydraulically or pneumatically operated press plate.