GB2041792A - Crimping tool - Google Patents

Abstract

In order to terminate a flat multi-conductor cable 20 to a multi-way connector element 6, 12, the two parts 6 and 12 of the element are fitted into recesses 5, (21) Fig. 2 (not shown) in two jaws 1 and 2. With the parts 6 and 12 of the connector element thus located, a multi-conductor cable 20 is placed over one jaw 2 and one part 12 of the connector element. The jaws are now forced together either by a bench vice or by tightening a screw (27) Fig. 4 (not shown) in a special clamp (25). This forces the connector element part 12 and cable 20 into the other part 6 of the connector element so that the contacts of the connector element are each forced into the cable's insulation so that each conductor is terminated by displacement of its insulation to one of the contacts in the connector element <IMAGE>

Description

SPECIFICATION Termination tooling for IDC type 'D' subminiature connectors This invention relates to a termination tool for an electrical connector element for attaching the connector to a flexible cable, also known as a ribbon cable.

The flexible cable under consideration each consists of a flat strip of insulating material within which a number of electrical conductors, which may be flat strip conductors or round cross-section conductors, are embedded. The conductors extend parallel to the length of the cable and each conductor is covered by the insulation.

Termination of such a cable is usually effected by contacts each of which ruptures the insulation over one of the conductors, and there is a need for a relatively simple tool for terminating such a cable to a multi-way connecting element. These elements, such as the connector elements of our well-known D sub-miniature type are of an elongate configuration.

Such a tool has to be able to terminate all conductors of such a flexible ribbon cable simultaneously and it is desirable if it can handle different sizes of connector elements. An object of the invention is to provide a tool which is relatively cheap and easy to use for terminating a ribbon c-able to a multi-way connector element.

According to the present invention there is provided a termination tool for terminating a multi-conductor flat cable to a multi-way connector element, which element is in two parts one of which has sharp-edged internal portions for its cable terminations, wherein the tool includes first and second jaw members which can be fitted together with their major dimensions parallel, one of the jaws being generally U-shaped and having keyways (or keys) in the U legs for cooperation with keys (or keyways) in the other jaw, wherein one of the jaws has a recess for the reception of one part of the connector element and the other jaw has a recess for the reception of the other part of the connector element, the recess in the other jaw being adjacent to locating means for a flat cable, wherein when the tool is in use said one part of the connector element is fitted into the recess in said one jaw while the other part is fitted into the recess in said other jaw, and wherein when the two parts of the connector element are thus fitted a flat cable is placed around the other jaw and the other part of the connector element with the conductors of the flat cable respectively aligned with the contacts of the connector element, whereafter the jaws are forced together, e.g, in a vice, to cause the insulation of the flat cable to be ruptured so that each said conductor is brought into electrically conductive connection with one of the contacts by insulation displacement.

An embodiment of the invention will now be described with reference to the accompanying drawings, in which: Fig. 1 is a view of a tool embodying the present invention with the jaws separated, and with one part shown separately above and to the right.

Fig. 2 is a view of one jaw of the tool, looking in the direction A, Fig. 1.

Fig. 3 is a top view of the tool of Fig. 1 with the jaws closed.

Fig. 4 shows how the tool of Figs 1-3 may be used under "in field" conditions.

The tool to be described is intended, inter alia, to overcome the problems which may arise when the pitch of the conductors in the ribbon cable does not accurately match the pitch of the contacts in the connector element to which the ribbon cable is to be terminated. In one case for which the tool described herein has been produced, the conductors are at 0.050" pitch while the contacts are at 0.054" pitch, both the connector elements and the cable being standard items already in production.

As will be seen from Fig. 1 , two shaped blocks 1, 2 or a suitably strong material, such as a mountable plastics material, are formed into jaws, so as to co-operate with each other. Jaw 1 is of generally U-shape, and it has slots 3,3, in its arm to form key ways to co-operated with keys such as 4 on the jaw 2. Note that the slots 3,3 are of different cross-section, as are the corresponding keys 4, so as to ensure correct alignment when the jaws are fitted together. Also the keys could be on the jaw 1 and the keyways on the jaw 2.

A stepped recess 5 in the jaw 1 receives the body 6 of the connector element, which body has its contacts fitted, Location bf the connector body is by pins such as 7 which fit into the normal mounting body in the flange of the connector body 6. Correct location and orientation of the connector body is controlled by the trapezoidal shape in the case of the D Subminiature (this shape may differ when such a tool is used for different sorts of connectors, in which case the shape of the recess 5 would also differ) and the locating pads 8 and 9, each of which carries one of the pins 7. Of these pads, pad 8 is fixed at the end of the recess 5, while the other pad 9 is moveable and can be fitted at different positions along the recess 5 to cater for different connector body sizes.The pad 9 has another pin extending from its rear, see this pad shown separately, which can be fitted into any one of a number of holes in the bottom of the recess 5. With two different and related connector element sizes, i.e. the related plug and socket shells, removal of the pad 9 from the recess and replacement of it with its pin in the same hole after turning the pad through -1800 enables the other plug connector element shell, which mates with the corresponding socket shell to be located. Here also the adaptation of the tool for different sorts of connector elements may need differently-shaped recesses and pads.

The second jaw 2 caters for one connector size only, and a range of such jaws is needed, one for each connector shell size, which with the current range of sizes of our D Subminiature connectors, needs four different jaws. The jaw 2 is generally wedge-shaped on its forward side, as can be seen from the drawing, while the back side is shaped as at 10, to facilitate fitting into 9 vice. The back of the jaw 1 is similarly shaped, as can be seen at 11.

Reverting to the jaw 2, as it has a recess on its front face which, with two slots 13, 1 4 on the upper edge of the recess continue to locate and retain the portion 1 2 of the connector element.

The upper and the lower faces of the wedgeshaped portion are relieved between the slots 13, 14 to provide upstanding ribs such as 1 5. Behind these walls and extending across the gap between the two slots 13, 14, there is a gap 1 6 through the rearward portions of the jaw 2. To retain the connector element part 12 and a flat cable in the jaw 2, two wedges 17, 18 are used, and these cooperate with portions such as 1 9 on the jaw 2.

Note that in the absence of the cable, the part 1 2 is a push fit in the jaw 2.

When a ribbon cable is to be terminated to a connector element, the appropriate sized connector element part 6 is selected, and the pad 9 set to its position appropriate to that part. The other part 12 of the connector element is then fitted into the recess in the jaw 2. The ribbon cable, indicated at 20, in the present case has its conductor at 0.050" pitch, i.e. not exactly corresponding to the contact pitch of 0.054", so the portion of the cable to be terminated to the connector element is split between conductors so that the latter are in groups with, for instance, three of four conductors in each group. Note that the connector element can be terminated to the cable at any position along the length of that cable.

The cable, after having been split as just mentioned, is passed over the assembly of the jaw 2 and the part 12 with the split conductor groups between the ribs such as 1 5. The rib spacing and cable splitting arrangement differ between connector sizes, and serve to eliminate the progressive pitch error between the conductors in the unsplit cable and the contacts.

Thus the ccnductors are nested in the recesses on the jaw 2, and the assembly of jaw 2, part 12 and cable 20 is held securely by the wedges 17 and 18.

The two "loaded" jaws 1 and 2 are now engaged and inserted into a bench vice, being located by the jaw portions 10 and 1 When the bench is tightened and closed the jaws 1 and 2 are forced together, which forces the part 12 and cable 20 into the part 6. As this occurs, the read ends of the contacts in the part 6 are forced into the cable, where they rupture the insulators so that the contacts are brought into electrically conductive connections with one of the conductors of the cable. Such a connection method is often referred to an insulation displacement connection.

One of the jaws has a built-in stop (not shown) to prevent over-crimping.

Fig. 2 is a front-on view of the jaw 2, and its recess, into which the connector element part 12 fits, is shown at 21.

Fig. 3 is a view from above of the tool in use with its jaws closed together.

Where the ribbon cable to be terminated is of a different variety, e.g. the twisted type sold under the trademark SPECTRA-STRIP, the shape of the wedges 17, 1 8 is suitably altered.

Where the tool is to be used "in the field", or in other conditions in which a bench vice cannot be used, a stirrup-shaped clamp 25, Fig. 4, is used.

This clamp fits over the ends of the jaw 1, its bentin ends engaging the projections on the outsides of the loop of the U. The other jaw 2 is shown with cut-away 26 for clarity, and this jaw which cooperates with the end of a tightening screw 27.

Rotation of the screw causes closure of the jaws to effect the connection by insulation displacement. The jaw 2 may have a recess in its centre to co-operate with the screw if desired.

Claims (4)

1. A termination tool for terminating a multiconductor flat cable to a multi-way connector element, which element is in two parts one of which has sharp-edged internal portions for its cable terminations, wherein the tool includes first and second jaw members which can be fitted together with their major dimensions parallel, one of the jaws being generally U-shaped and having keyways (or keys) in the U legs for co-operation with keys (or keyways) in the other jaw, wherein one of the jaws has a recess for the reception of one part of the connector element and the other jaw has a recess for the reception of the other part of the connector element, the recess in the other jaw being adjacent to locating means for a flat cable, wherein when the tool is in use said one part of the connector element is fitted into the recess in said one jaw while the other part is fitted into the recess in said other jaw, and wherein when the two parts of the connector element are thus fitted a flat cable is placed around the other jaw and the other part of the connector element with the conductors of the flat cable respectively aligned with the contacts of the connector element, whereafter the jaws are forced together, e.g. in a vice, to cause the insulation of the flat cable to be ruptured so that each said conductor is brought into electrically conductive connection with one of the contacts by insulation displacement.

2. A tool as claimed in claim 1, wherein the length of the recess in said one jaw is adjustable to cater for different sizes of connector element.

3. A tool as claimed in claim 1 or 2, wherein a stirrup-shaped clamp is provided which embraces the two jaws, the clamp having a screw for tightening the jaws together.

4. A termination tool for terminating a flat ribbon cable to a multi-way connector element, substantially as described with reference to Figs.

1,2and3,orFigs. 1,2,3and4ofthe accompanying drawings.