GB2032709A - Electrical contact for an electrical connector - Google Patents

Abstract

An electrical connector contact 100 includes a conductive body 110 having a forward socket for receiving a plurality of contact wires 120 and a rear socket for receiving an electrical conductor 130. The wires 120 extend outwardly from the forward socket and are protected by a sleeve 140, which is mounted to the body 110 coaxially therearound by a crimp 146. The sleeve provides a housing into which a second contact may be inserted and in which the wires from the two contacts may be intermingled in mated, current-transmitting relationship. The sleeve allows the content to be inserted through a grommet at the rear end of a connector housing without damaging the grommet. <IMAGE>

Description

SPECIFICATION Electrical contact for an electrical connector The present invention relates to electrical connectors and contacts for use in electrical connectors. More particularly, the present invention relates to an improvement to electrical contacts of the type including forward axially aligned wires, each having an acutely angled forward end surface.

The present invention is related to an improvement upon U.S. Patent 3,725,844, issued April 3, 1973 to Mckeown et al. for "Hermaphroditic Electrical Contact", assigned to the assignee of the present invention. This patent is hereafter referred to as the "Brush Contact Patent" and the specification and drawings thereof are hereby specifically incorporated herein by reference.

Some electrical connectors are known in which a plurality of axially aligned wires, each having acutely angled forward end surfaces, are mounted in contacts including sockets. In the referenced Brush Contact Patent, several such contacts are shown.

In some applications, the axially-aligned wires extend outward from both of the sockets. In many applications, the outward extension of the axially aligned wires is not a disavantage. However, in some applications, it is desired to mount the contact from the rear through a moisture protecting grommet. This grommet has rubber webs which are resilient and will expand when a member passes through, but the webs are vulnerable to damage by sharp objects such as the angled end surfaces.

The Brush Contact Patent suggested an arrangement where a one-piece contact body had a forward portion which extended beyond the ends of the wires.

This contact had a forward socket longer than the wires, with the brush wires inserted into the socket. The manufacture of such contacts was relatively difficult and expensive and which were not necessarily uniform. Further, these contacts were difficult to inspect because the entire length of axially aligned wires was hidden from view.

This arrangement required the separate manufacturing and inventorying two types of holders and two types of completed contacts.

While contacts are relatively inexpensive individually, there is expense and burden in providing the two separate types.

In other applications, it is desired to protect the angled end surfaces ant the aligned wires by surrounding them with a protecting layer of metal.

In some applications, a contact must be inserted through a member having a small aperture which is susceptible to damage from the tapered wire ends. One such member is a grommet which provides moisture protection.

The present invention overcomes the disadvantage and limitations of the prior art by providing an electrical contact for use as an electrical conductor termination in an electrical connector, said contact comprising: a body having an electrically conducting portion and a passage extending rearwardly from a forward end of the body and a portion adapted to receive an electrical conductor at the rear end, and a plurality of axially-aligned wires mounted in the passage and extending forwardly from the body, the forward ends of the wires extending beyond the forward end of the body, characterized in that a separate elongated sleeve member having a central opening extending through its length from a forward aperture is telescopically mounted to the body at the rear thereof and extends forwardly threfrom, said elongated member surrounding the plurality of wires and extending forwardly of the forward ends of the wires to protect the wires.

The present invention has the advantage that the contact is relatively easy to manufacture, assemble and inspect.

The contact of the present invention is also relatively inexpensive in manufacturing and inventory cost in that only one hermaphroditic body and contact (with separate unassembled sleeves) need be inventoried.

The contact of the present invention with the sleeve in place may be inserted through a grommet aperture with ease and without damaging the contact or the grommet.

The invention will now be described with reference to the accompanying drawings, wherein: Figure 1 is a perspective view of an electrical contact of the prior art, similar to that described in the Brush Contact Patent; Figure 2 is a partial cross-sectional view of a contact of the type shown in Fig. 1 with a removable sleeve or shroud mounted thereon; and Figure 3 is a partial cross-sectional view of an alternate embodiment of a contact of the type shown in Fig. 2, having a removable sleeve mounted thereon.

Fig. 1 is a perspective view of an electrical contact 100, similar to that shown in the referenced Brush Contact Patent. The contact 100 includes a body 1 1D, plurality of fine, "brush" wires 120, and is coupled to an electrical conductor 1 30.

The body 1 10 includes a forward portion 111 which has an internal socket 11 2 extending axially rearward from the forward end of the contact body 110. The forward portion 111 includes an inwardly crimped region 11 3 for securely retaining the wires 1 20 therein.

The body 1 10 also includes a medial enlarged portion or annular shoulder 11 4 which extends radially outward from the rest of the body, and provides a means for retaining the contact within a passage of a connector housing. The retention system and housing passage are not described in detail because there are several systems which will work adequately with contacts of the present intention.

One such system is described in U.S. Patent 4.082.398 to Bourdon et al, and the specification and drawings of that patent are hereby incorporated specifically by reference.

The rear portion of the contact body 110 includes an internal axial passage or socket 11 5 extending forwardly from the rear end. A crimp 11 6 in the rear portion of the contact body allows the conductor 1 30 to be retained therein. As inspection hole 11 7 allows the forward end of the conductor to be inspected for its preparation and location during crimping.

The wires 1 20 are described in considerable detail in the referenced brush contact patent, to which reference should be made for further details. The brush wires 1 20 are axially aligned and arranged in a bundle in close proximity with each other. A forward end 1 22 of each wire has an acutely angled or tapering, forward end surface, preferably having a 30 degree acute angle. The rear portions of the axially aligned wires are inserted into the socket 11 2 and secured in place within the socket 112 by the crimp 113. The crimp 113 prevents the wires 1 20 from becoming separated from the contact body 110 and maintains the rear ends of the wires 1 20 in the proper axial alignment.The wires 1 20 are preferably made of beryllium copper and are manufactured to a high degree of straightness before use. The wires preferably are 0.008" in diameter and the wire bundle, in its preferred embodiment, includes seven wires.

The conductor 1 30 is an insulated wire, preferably including several conducting strands wrapped by a layer of protecting insulation. The insulation has been removed from a forward end of the conductor 130, exposing the conducting strands 131, in a region which is within the rear socket 11 5 of the contact body 110. The exposed strands 131 are visible through the inspection hole 11 7. The purpose of the inspection hole 11 7 is to ascertain that the insulation has been indeed removed from the conductor 1 30 in the forward region and that the forward end of the conducting strands has been fully inserted within the socket.

Fig. 2 shows the electrical contact 100 of the type described in Fig. 1, with a sleeve 140 mounted over the forward contact body portion 111. The contact 100 includes the contact body 110, and the wires 120, with a rear mounted electrical conductor 1 30 as described in conjunction with Fig. 1.

The sleeve or shroud 140 as shown in this view is substantially a hollow cylinder and is preferably made from brass which is preferably (but may not be) plated. The sleeve 140 has an inside diameter of the forward portion 111 of the contact body. When aligned concentric with the contact body forward portion 111, the sleeve 140 may be slipped over the forward body portion 111.

The sleeve 140 includes a forward portion 142 which may be tapered inwardly and rearwardly to the inside diameter of the sleeve 1 40. The forward end 1 42 extends forwardly of the angled end surfaces 1 22 of the wires 1 20. Thus, the sleeve extends outside of and forwardly of the wires to protect them and isolate them. Advantageouly, the sleeve 140 is large enough to allow the mating of the contact wires in one contact with the wires from another contact without interference, while being small enough to slip through the contact retention system, including a forward stop (as shown in U.S. Patent 3.165.369 to Maston) or a forward set of retention fingers (as shown in U.S. Patent 4.028.398 to Bourdon et al.).

The sleeve 140 includes a rear end face 144. The sleeve 1 40 is placed in axial alignment with the forward contact portion 111 and the sleeve is telescoped over the forward contact portion 111 until the rear face 1 44 is in contact with the enlarged portion 114. The enlarged portion 114 provides a positive stop for the rearward movement of the sleeve.

When the sleeve 140 has been properly positioned on the contact forward portion 111, the sleeve 140 is secured in place by a plurality of radial extending crimp 146 which prevents the sleeve from moving axially or radially with respect to the body 111. Such crimps, and apparatus for making such crimps in an automated process, are well known in the art. In some manufacturing operations, it may be possible to make the sleeve securing crimps 146 and the wire-securing crimps 11 3 simultaneously, while in other applications it may be desirable to make the wire securing crimps first before assembling the sleeve, and the sleeve-securing crimps later.

Fig. 3 shows an alternate ebodiment of the contact and sleeve arrangement of Fig. 2. An electrical contact 200 includes a first body piece 210, including a plurality of axially aligned wires 220. A sleeve piece 240 is mounted to the body 210 at its forward end and is crimped in place.

The body piece 210 does not have separately machined sockets, but is formed from a tubular piece of stock with a wall portion 215 cut out and bent inward to provide a rear stop for the wires 220. Where the wall portion 215 has been bent inward, an aperture 216 has been created by its removal and serves as an inspection port or hole to ascertain that the conductor inserted from the rear end has been properly prepared and completely inserted.

The body 210 includes a medial enlargement 21 8 which serves as a rear stop for the sleeve 240.

The sleeve 240 preferably has been formed from a tubular stock which has been formed to have a neckdown portion 242 and an enlarged rear portion 244. The neckdown portion 242 provides an internal stop, up to which the body member 210 is inserted. The enlarged rear portion 244 is used for contact retention, providing the necessary enlarged medial portion to engage the contact retention fingers and/or stops which are associated with a housing passage. The body member 210 has crimps 218 extending radially inward to retain the contact wires 220 in place and the sleeve 240 includes inwardly-extending crimps 246 which fix the sleeve 240 to the body member 210.

The contact shown in Fig. 3 is adapted to have an electrical conductor (not shown) mounted to the rear end thereof. The conductor would be inserted until the forward end is substantially in contact with the rear face of the wall portion 21 5. Thereafter, the conductor would be secured in place in the body 210 by suitable means, such as by crimping the body and the conductor.

The electrical contact in Fig. 1 may be considered a hermaphroditic contact, and two of such contacts may be used as a mateable pair in some applications. In other applications, it is desirable to have "male" and a "female" contact. The Fig. 2 modification of the contact to Fig. 1 provides a male-female assembly (the Fig. 1 and the Fig. 2 embodiments). The Fig. 2 embodiment also provides a protective shield around the contact wires of the one member to protect them during insertion and use. Since some of the electrical connector housings include a rear mounted grommet, having a plurality of rubber webs associated with each passage, and since a rear inserted contact must pass through the grommet webs, such protection is advantageous for the brush wires and the rubber grommets.

The contact of Fig. 1 and the separate shroud 140 may be separately inventoried to allow the freedom to choose a hermaphroditic contact or a male-female contact (as the need arises) and to allow the simple and inexpensive conversion from one type of contact to another.

The Fig. 3 contact, without the sleeve 240 being mounted thereon could be similarly used in inventory, along with the separate sleeves 240 which might be installed at the time of use. In some applications of the Fig. 3 contact without the sleeve 240, it may be desirable to provide an additional piece mounted over the enlargement 21 8 to provide a better shoulder for retention purposes.

The foregoing description is illustrative of the preferred and alternate embodiments of the present invention. Other modifications and substitutions for the features of the present invention will be apparent to one skilled in the art. For example, a brush contact including more than the disclosed seven wires, such as nineteen or thirty-seven wires, could be used to advantage. Other methods for securing the conductor or the contact wires within the socket could be quite simply substituted. Further, some of the features of the present invention may be used to advantage without the corresponding use of other features. The foregoing description, accordingly, should not be considered to limit the scope of the invention, which is defined solely by the following

Claims (2)

claim. CLAIMS

1. An electrical contact for use as an electrical conductor termination in an electrical connector, said contact comprising: a body having an electrically conducting portion and a passage extending rearwardly from a forward end of the body and a portion adapted to receive an electrical conductor at the rear end, and a plurality of axially-aligned wires mounted in the passage and extending forwardly from the body, the forward ends of the wires extending beyond the forward end of the body, characterized in that a separate elongated sleeve member having a central opening extending through its length from a forward aperture is telescopically mounted to the body at the rear thereof and extends forwardly therefrom, said elongated member surrounding the plurality of wires and extending forwardly of the forward ends of the wires to protect the wires.

2. An electrical contact substantially as described and as shown in the accompanying drawings.