CA1112322A - Electrical contact for an electrical connector - Google Patents

Abstract

ELECTRICAL CONTACT FOR AN ELECTRICAL CONNECTOR

ABSTRACT OF THE DISCLOSURE

An electrical connector contact in which the contact includes a hermaphroditic body having a forward socket for receiving a plurality of axially aligned wires and a rear socket for receiving an electrical conductor. The wires extend outwardly from the forward socket and are protected in one of the two mating contacts by a sleeve or shroud which is separately manufactured and mounted to the body coaxially therearound and extends forwardly of and radially outside of the axially aligned wires to protect them. The sleeve is mounted to the body by a crimp and protects the wires while providing 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.

Description

The present invention relates to electrical connectors and contacts Eor use in electrica] connectors. More particularly, the present invention relates to an improvement to electrical contacts of the type including a for~ard axially aligned wires, each having an acutely angled forward insert.
The present invention is related to an improvement upon U.S. Patent 3,725,844, issued April 3~ 1973 to MGKeown et al. for "Hermaphorditic Electrical Contact", assigned to the assignee of the present invention. This patent is hereafter referred to as the "Brush Contact Patent".
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The present invention is also re]ated to copending Canadian patent applicatlon Serial No. 334,172~ filed on August 21, 1979 by Niles, Normann, and Whallon~ Jr., entitled "Electrical Connector Assembly".
Some electrical connectors are known in which a ; plurality of axially-aligned wires, each having acutely angled forward bend surfaces, are moùned in contacts inciuding sockets. In the Brush Contact Patent, several such contacts are shown~
In some applications~ the axially-aligned wires extend outward from both of the sockets. In many applications9 the~outward extension of the axlally aligned wires is not a ~ ~ disadvantage. However9 in some applications9 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 mb/Jo - 1 -: , . . . : ~ 1.

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The Brush Contact Patent suggested an arrangement where a one-piece contact body had a ~orward portion which extended beyond the ends of the wires.
This contact had a for~ard socket longer than the wires, with the brusil wires inserted into the socket. The manufacture o~ such contacts was rela~ively 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 separa~e 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 prov:Lding the two separate types.
In other applications, it is desired to protect the angled end surfaces and the aligned wires by surrounding them with a protecting layer of metal~

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In some applications9 a contac~ must be inserted through a member having a small aperture which is susceptible to damage. from the tapered wire ends. ~ne such member is a gromm~t~ which provides ~oisture protection.

The foregoing and other limi~ations and dtsadvantages of the prior art wîll be apparent to those skilled în the art in view of the following descrip~ion and claims and appended drawings.

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~ ccording t-o the present i.nvention there is provided an electr:ical connecCor which has a housing w:Lth a passaKe e~tending theretllrough and an elongated electrical contact including a body extending in the direction of the contact ].engtll and having an external enlarged portion intermediate the length and an internal bore extending rearwardly from a forward end of the bocly. A plurality of axially-aligned wires is held within the internal bore and extends forwardly from the body~ Means is provided Eor protecting the wires from damage and for preventing the wires ~rom damaging a grommet. The means includes a separate sleeve member mounted in the body and extending through and forwardly of the axially-aligned wîres to protect the wires from damage.
Means is also provided for releasably mounting the contact withln the housing passage.
The present invention has the advantage that the contact is relatively easy to manufacture, assemble and nspect .
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 i.nvention with the sleeve in place may be inserted through a grommet aperture with ease and without damaging the contact or the grommet.

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: Othe~ objects and advaDtages of the present inventlon will be obvious to one skllled in the.art in view of the following appende~ descriptlon and claims and the accompanying drawings.
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BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE 1 is a perspective view of an electrical contact of the prior art, similar to that described in the Brush Gontact Patent.

FIGURE 2 is a partial cross-sectional view of a contact of the type shown in FIGURE I with a removable slePve or shroud mounted thereon.

FiGURE 3 is a partial cross-sectional view of an alternate ambodi- -ment of a con~act of the type shown in FIGURE 2, having a removable : sleeve mounted thereon.

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DETAILED DESCRIPTION OF THE DRAWINGS
~ _ _ . _._ ... . . _ FIGURE 1 is a perspective view oE an electrical contact 100, similar to that shown in the ~rush Contact Patent. The contact 100 includes a body 110, a plurality of Eine, "brush"
wires 120, and is coupled to an electrical conduc-~or 130.
The body 110 includes a forward portion lll which has an internal socket 112 e~tending a~ially rearward from the forward end of the contact body 110. The forward portion 111 includes an lnwardly crimped re~ion 113 for securely retaining the wires 120 therein.
The body 110 also includes a medial enlarged portion or annular shoulder 114 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~
The rear portion of the contact body 110 includes an internal axial passage or socket 115 extending forwardly from the rear end. A crimp 116 in the rear portion of the contact body allows the conductor 130 to be retained therein. ~n inspection hole 117 allows the forward end of the conductor to be inspected for its preparation and location after crimping.
The wires 120 are described in considerable detail in the Brush Contact Patent. The brush wires 120 are a~ially align~ed and arranged in a bundle ln close proximity with each other. A forward end 122 of each wire has an acutely angled, or ~apering, forward end surfaee, preferably having a 30 degree ..
included angle. The rear portions of the tml~ 6- `

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axially aligned wires are inserted into the socket 112 and sec.ured in place within the socket 112 by the crimp 113. The crimp 113 prevents the wires 120 from becoming separated from the contact body 110 and maintains the rear ends of the wires 120 in the proper a~.ial alignment.
The wires 120 are preferably made of beryllium copper and are manufactured to a high degree of straightness ~efore use. The wires preferably are o.oo8~ in diameter and the wire bundle, in its preferred embodiment, includes seven wires.

The conductor 130 is an insulated wire, preferably including several conducting strands wrapped by a layer of protecting insulation.
The insulation has been removed from a forward ~nd of the cor.ductor 13G, exposing the conducting strands 131, in a region which is ~ithin the rear socket 115 of the contact body 110. The exposed strands 131 are visible through the inspection ho1e 117. The purpose of the inspection hole 117 is to ascertain that the. insulation has been indeed been remove~
from the conductor 130 in the forward region and that the forward end of the conducting strands has been fully inserted within the socket.
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FIGURE 2 shows the electrical contact 100 of the type described in FIGURE 1, with a sleeve 140 mounted over ~he for~ard contact body portion 111. The con~ac~ lOC inc.ludes the contact body 110, and the wires 120, with 2 rear mounted electrical conductor 130 as described ~:
in cor,junction with FIGURE 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 which is slightly larger than the outside 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.

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The sleeve 140 includes a forward portion 142 which may be tapered inwardly and rearwardly to the inside diameter of the s7eeve 140. The forward end 142 extends fonwardly of the angled end surfaces 12~ of the wires 120. Thus, the sleeve ex~tends outside of and forwardly of ~he wires to pro~ect them and isolate them. Advantageously, the sleeve 140 is large enough ~o allow the mating of the contact wires in one con-tact with the wires from another contact withou~ interference, while being small enough to slip through the contact retention system, in-cluding a forward stop (as shown in U.S Patent 3,165,369 to Maston~
oa 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 140 is p1aced in axial alignment with the forward contact portion 111 and the sleeve is ~elescoped over the forward contact portion 111 until the rear face 144 is in contact with the enlarged portion 114. The enlarged por~ion 114 provides a posi~ive stop for the rearward movement of the sleeve.

When the slee~e i40 h~ss been properly positioned on the contact forward portion 111, the sleeve 140 is secured in place by a plurality ~o of radial extending crimp 146 which prevents the sleeve from movins a~ia11y or radially with respect to the body 111. Such crimps9 and apparatus for making such c:rimps in an automated process, are well known in the art. In sorne manufacturing opera~ions, it may be possible to make the sleeve-securing crimps 146 and t.he wire-securing crimps 113 simultaneously, while in other applications it may be desirable to make the wire securing crimps first before assembling the sleeve, and the sleeve-securing crlmps later.

- ~ FIGURE 3 shows an alternate embodiment of the contact. and sleeve arrangement of FIGURE 2. An electrical. contact 200 includes a ~irst body piece 210, including a plurality of actually aligned wires 220.
A sleeve piece 240 is mounted to the body 210 at its forward end and is crimped in place.

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The body piece 210 does not h~nve separately machine 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 beer, bent inward, an aper~ure 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 bocly 210 includes a medial enlargerrent 218 which serves as a rear stop for the sleeYe 2~0.

The sleeve 240 preferably has been formed from the tubular stock which has been formed to have a neckdown portion 242 and an enlarged rear portion 244. The neckdown portion 242 provides an in~ernal stop, up to which the bc,dy member 210 is inserted. The enlarged rear portion 244 is used for contact retention, providing the necessary enlarged medial portion to engaae the contact retention fingers and/or stops which are associated with housing passage. The body member 210 has crimps 218 extendiny radially inward to retain the ccntact wires 220 in place and the sleeve 240 includes inwardly-eYtending crimps 246 which fix the 51 eev~ 240 to the body member 210.

The contact shown in FIGURE 3 is adapted to have an electrical con-ductor (now s~own~ mounted to the rear end thereof. The ccnductor wouldbe inserted unt71 the forward end is substant;ally in contact with the rear face of the piece 215. Thereafter, the conductor would be secured in place in the body 210 by suitable means, such as by crimpinc ~he body and the conductor.

The electrical sontact in FIGURE i may be cor,sidered a hermaphroditic contact, and two of such contacts rnay be used as a ma~eable pair in some applications. In other applications, it is desirable to have "nknle" and a "Female'I contac~ The FIGL,RE 2 modification of the contact to FiGURE 1 provides a male-female assembly (~he FIGURE 1 and the FIGURE 2 embodiments).
The FIGURE 2 embodiment also pro\rides a protective shi~eld around the ~ contact wires of the one member to protect them during insertion and use.

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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 con~act of FiGURE 1 and the separate shroud 140 may te separately inventoried to allow the freedom to choose a hermaFhroditic contact or a male-female contact (as the need arises) and to allow the simple and inexpensive conversion from one type oF con~act to another.

The F~GURE 3 contact, without the sleeve 240 being mounted therein, 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 FIGURE 3 contact without the sleeve 2LIO, it may be desirable to provide an additional piece mounted over the enlargement 21~ to provide a better shoulder for retention purposes.

The foregoing description is illustrative of the preferred and alternate embodiments of the present invention. Other modificat;onc 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 ; 20 than the disclosed seven wires, such as nineteen or thirty-seven wires~
could be used to advantage. Other rrethods for securlng the conductor or the contact wires within the socket could be ~uite 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 tf the In~ention, which is deFined solely by the follo~ing claims.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An electrical connector comprising:
a housing having a passage extending therethrough;
an elongated electrical contact including: a body extending in the direction of the contact length and having an external enlarged portion intermediate the length and an internal bore extending rearwardly from a forward end of the body;
a plurality of axially-aligned wires held within the internal bore and extending forwardly from the body; and means for protecting the wires from damage and for preventing the wires from damaging a grommet, said means including a separate sleeve member mounted to the body and extending around and forwardly of the axially-aligned wires to protect the wires from damage;
and means for releasably mounting the contact within the housing passage.