US3845459A

US3845459A - Dielectric sleeve for electrically and mechanically protecting exposed female contacts of an electrical connector

Info

Publication number: US3845459A
Application number: US00336309A
Authority: US
Inventors: R Normann
Original assignee: Bendix Corp
Current assignee: Amphenol Corp
Priority date: 1973-02-27
Filing date: 1973-02-27
Publication date: 1974-10-29
Anticipated expiration: 1991-10-29
Also published as: GB1422756A

Abstract

An electrical connector assembly of the type having a plurality of male pin-type contacts that mate with a plurality of female socket-type contacts that includes a dielectric sleeve mounted around the exposed portion of each of the female contacts. The dielectric sleeve reinforces the mechanical strength of the female contacts, protects the female contacts from damage, prevents ''''flashover'''' between female contacts that would occur because of the closer spacing between the female contacts than the male contacts, and prevents mating of the female contacts with oversized male pin-type contacts.

Description

United States Patent [1 1 Normann Oct. 29, 1974 I 1 DIELECTRIC SLEEVE FOR ELECTRICALLY AND MECHANICALLY PROTECTING EXPOSED FEMALE CONTACTS OF AN ELECTRICAL CONNECTOR Richard W. Normann, Otego, NY.

The Bendix Corporation, Southfield, Mich.

Filed: Feb. 27, 1973 Appl. No.: 336,309

Inventor:

Assignee:

US. Cl. 339/191 R, 339/59 R, 339/213 R Int. Cl H011 19/28 Field of Search, 339/59, 191-193,

References Cited UNITED STATES PATENTS l/1916 Pearl et a1 339/196RX 3/1958 Rhodes 339/75 M X 2/1961 Colwell 339/213 R X 10/1961 Purinton 339/258 R X 3,059,208 10/1962 Concelman 339/213 R X 3,377,613 4/1968 Archer 339/191 R X FOREIGN PATENTS OR APPLICATIONS 110,047 5/1925 Switzerland 339/192 R Primary Examiner-Roy D. Frazier Assistant Examiner-Lawrence J. Staab Attorney, Agent, or Firm-Raymond J. Eifler [5 7 ABSTRACT 3 Claims, 4 Drawing Figures own 1 BEST EVAILABLE COPY DIELECTRIC SLEEVE FOR ELECTRICALLY AND MECHANICALLY PROTECTING EXPOSED FEMALE CONTACTS OF AN ELECTRICAL CONNECTOR BACKGROUND OF THE INVENTION This invention relates to multipin electrical connectors of the type having male pin-type contacts that mate with female socket-type contacts in the other half of the connector assembly. This invention is more particularly related to a dielectric sleeve that is mounted on the female socket contact to improve the electrical performance of the connector.

In pin and socket-type multipin electrical connectors, the breakdown voltage between adjacent contacts, i.e., the disruptive discharge through air between two adjacent contacts of different potential, is a function of the distance between the two adjacent surfaces. It should be readily appreciated that female socket contacts, arranged and spaced to mate with similarly arranged male contacts having a smaller diameter, will have a breakdown or flashover voltage that is lower than that associated with the male contacts. In any electrical connector, the voltage rating is determined by the weakest link in the chain and therefore the voltage rat ing of the connector generally does not exceed the voltage at which flashover or breakdown occurs between two female contacts. Further, socket-type female contacts are subject to mismating with connector elements that contain pin-type male contacts that are sized for mating with larger sized sockets. Mis'mating causes the sockets to be expanded so that in subsequent matings with properly sized contacts poor or intermittent electrical contact is established between the mechanically mated male and female contacts.

SUMMARY OF THE INVENTION This invention provides an electrical connector assembly wherein the breakdown voltage between two adjacent female contacts is greater than the breakdown voltage between two adjacent male contacts. The invention further provides a means for improving the electrical performance of all multipin pin and sockettype electrical connectors and to prevent mismating of the socket contact with oversized male pin contacts.

The invention is an electrical connector assembly characterized by an electrical connector element that includes a dielectric sleeve (30) mounted on and surrounding the mating portion of the female socket contacts which may be removably or fixably mounted in a connector insert The opening (31) in the sleeve (30) is sized to receive male contacts (100) not exceeding a predetermined diameter.

In one embodiment of the invention, an electrical connector that accomplishes the objects of the invention comprises: a first assembly having an insert (200), a plurality of bores arranged in a predetermined spaced relationship in the insert (200), and a plurality of male contacts (100), each disposed in one of the bores; and a second assembly separably connectable to the first assembly, the second assembly including an insert (20) having a front face (21) and a rear face. a plurality of bores through the second assembly insert (20) from the front face (21) to the rear face, the bores arranged in the same spaced relationship as the bores in the first assembly insert so that when the first and second assemblies are connected together, the axis of the bores in the first insert are aligned with the axis of the bores in the second insert; a plurality of female contacts (10), each mounted in one of the bores of the second insert (20), each of the female contacts (10) having a resiliently expandable mating portion (14) that extends out of the second insert (20) from the forward face and a groove (12) in the forward portion of the female contact (10); and a sleeve (30) comprised of insulating material mounted on each of the female contacts (I0), the insulating sleeve (30) surrounding the mating end (14) of the female contact (10) that extends from the front face (21) of the insert (20), the sleeve (30) including an internal annular shoulder (32) that engages the groove (12) in the female contact (10) to maintain the insulating sleeve (30) in a fixed mounted position around the contact mating end (14) and an opening (31) in the mating end (14) of the -sleeve (30) sized to receive male pin-type contacts not exceeding a certain predetermined diameter.

Accordingly, it is an object of this invention to provide that portion of an elecrical connector assembly that contains the female socket contact elements with means for preventing electrical breakdown between adjacent contacts.

It is another object of this invention to provide a sleeve that reinforces the strength of a female socket contact, protects the female socket contact from damage, and provides electrical isolation between adjacent BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional diagrammatic view of a mateable electrical connector assembly that embodies the principles of this invention.

' FIG. 2 illustrates a plan view of a female socket type electrical contact.

FIG. 3 illustrates a cut-away view of a dielectric sleeve used to accomplish the objects of this invention.

FIG. 4 illustrates a side view of the socket contact shown in FIG. 2 illustrating the shape of the female contact.

DETAILED DESCRIPTION OF THE DRAWINGS 1 Referring now to the drawings, FIG. 1 illustrates portions of a mateable electrical connector assembly that embodies the principles of this invention. The first half (1) of the connector assembly includes a plurality of male pin-type contacts (100) that arranged in a predetermined spaced relationship in an insert.(200). The forward end of the male contacts (100) are adapted to mate with socket-type female contacts.

The second half (2) of the connector assembly that is mateable in a separable manner to the first half (1) of the connector assembly includes a dielectric insert (20); a plurality of contacts (10) mounted in the di-' electric assembly (20); and a plurality of sleeves (30), comprised of an electrically nonconducting material, mounted on each of the female electrical contacts The insert includes a forward face (21 from which the forward portion of the electrical contact (10) extends to receive and mate with the forward portion of the male pin-type contacts (100). Each of the female contacts (10) includes an enlarged portion (11) that secures the contact (10) within the insert (20). The forward portion of the contact (10) includes a male contact receiving portion or mating portion (14) that further includes one or more axial slots (13) so that the forward mating portion (14) of the contact (10) is resiliently expandable radially so as to provide pressure contact between the mating end (14) of the female socket-type contact (10) and the pin portion of the male contact (100).

The dielectric or insulating sleeve (30) is mounted on the forward portion of the female contact (10) so as to surround the portion of the female contact (10) that extends beyond the first face (21) of the insert (20). The dielectric sleeve may be comprised of teflon, nylon, thermoplastic or a thermosetting plastic so that the sleeve (30) may be telescopically mounted on the female contact (10) and held in place either by pressure contact or by some other suitable means. The rigidity of the sleeve (30) protects the female contacts (10) from damage due to blows or inadvertent engagement with noncontact members. Further, the dielectric sleeve (30) reinforces the strength of the socket contact (10) and provides electrical isolation between the contacts over that portion of the contact (10) that is not surrounded by the insert (20). Additional features of the dielectric sleeve (30) includes an opening (31) that is sized to receive a contact that does not have a diameter greater than a predetermined dimension. Therefore, the opening (31) prevents damage to the female contacts (10) by preventing engagement of the female contact 10) with noncontact type members and/or male pin-type contacts that are oversized and should not be inserted into the female contacts (10). Obviously, mismating of socket-type female contacts (10) with oversized male pin-type contacts can either break the mating end portions (14) of the female contact that are located between axial slots (13) and/or deflect this divergent portion of the mating end (14) so that subsequent mating with correct sized male contacts cause intermittent electrical signals between the male and female contacts because there is no physical contact or insufficient pressurized contact between the male and female contacts.

FIG. 2 illustrates a female socket-type electrical contact (10) that includes a means (12) for securing a sleeve (30, FIG. 1) to the electrical contact (10). The electrical contact (10) includes an enlarged portion (11 that permits the electrical contact to be fixedly or removably mounted with a connector insert. The axial slots (13) in the mating portion (14) of the contact (10) defines a plurality of fingers that extend radially inwardly with respect to the axis of the socket to make the forward mating portion (14) of the contact (10) resiliently expandable so that when a pin-type contact (100) is inserted into the mating end (14) of the contact (10), the male and female contacts are in pressurized contact. To more securely fasten the sleeve (30, FIG. 1) to the contact (10), the contact (10) includes an annular groove (12) for receiving an internal shoulder in the sleeve (30, FIG. 3).

FIG. 3 illustrates a cut-away view of the dielectric sleeve (30) that accomplishes the objects of the invention when used in combination with an electrical connector of the type shown in FIG. 1. The sleeve (30) includes a male contact receiving end portion that has an inwardly tapered opening (35) for guiding a male pin (not shown) into the opening (31) which further guides the male pin into the female socket-type contacts (10, FIG. 1). Although the sleeve (30) may be mounted on a contact (10) and held in place by pressurized contact, it is preferred that the sleeves (30) have an internal annular shoulder (32) that mates with and/or engages the groove (12) of the contact shown in FIG. 1. Preferably, the sleeve is comprised of plastic which allows the shoulder (32) to resiliently deform as the sleeve (30) is telescopically moved into position on the female contact (10) when the internal shoulder (32) of the sleeve (30) reaches the groove (12) in the contact (10), an audible snap is heard that notifies the assembler that the sleeve is now properly in place on the contact. Referring again to FIG. 1, it can be seen that the sleeves (30) electrically isolates each of the female contacts (10), one from another. FIG. 4 is a side view of FIG. 2 that illustrates the shape of the contact and the location of the axial slots (13). v

While a preferred embodiment of the invention has been disclosed, it will be apparent to those skilled in the art that changes may be made to the invention as set forth in the appended claims and, in some instances, certain features of the invention may be used to advantage without corresponding use of other features. For example, .although the dielectric sleeves (30) are shown to be snapped in the contact (10), the sleeve (30) may be cemented or bonded with adhesive to the contact (10). Accordingly, it is intended that the illustrative and descriptive materials herein be used to illustrate the principles of the invention and not to limit the scope thereof.

Having described the invention, what is claimed is:

1. In combination with an electrical connector element of the type having an insert and a plurality of female contacts mounted therein with the mating end of the female contact extending from one face of said insert, each of said female contacts including an enlarged portion and a forward portion that includes the mating end and an annular groove having a rearwardly facing shoulder in the forward portion of the contact, the improvement comprising:

a plurality of sleeves comprised of electrically insulating material, each mounted on the forward portion of one of said female contacts and completely surrounding said mating portion of said contacts, each of said sleeves including an internal projection having a forwardly facing shoulder that mates with the annular groove in said female contact and engages the rearwardly facing shoulder of said groove to secure the dielectric sleeve to the forward portion of said female contact and wherein each of said sleeves includes a forward male contact receiving end portion that tapers radially inward with respect to the axis of said sleeve from free end so as to provide a means for guiding a male contact into said sleeve and said mating portion of said female contact.

6 2. The connector element as recited in claim 1 mits the resilient deformation of said internal shoulder wherein said sleeve is comprised of plastic. on said sleeve when said sleeve is telescopically 3. The connector element as recited in claim I mounted on said female contact. wherein said sleeve is comprised ofamaterial that per-

Claims

1. In combination with an electrical connector element of the type having an insert and a plurality of female contacts mounted therein with the mating end of the female contact extending from one face of said insert, each of said female contacts including an enlarged portion and a forward portion that includes the mating end and an annular groove having a rearwardly facing shoulder in the forward portion of the contact, the improvement comprising: a plurality of sleeves comprised of electrically insulating material, each mounted on the forward portion of one of said female contacts and completely surrounding said mating portion of said contacts, each of said sleeves including an internal projection having a forwardly facing shoulder that mates with the annular groove in said female contact and engages the rearwardly facing shoulder of said groove to secure the dielectric sleeve to the forward portion of said female contact and wherein each of said sleeves includes a forward male contact receiving end portion that tapers radially inward with respect to the axis of said sleeve from free end so as to provide a means for guiding a male contact into said sleeve and said mating portion of said female contact.

2. The connector element as recited in claim 1 wherein said sleeve is comprised of plastic.

3. The connector element as recited in claim 1 wherein said sleeve is comprised of a material that permits the resilient deformation of said internal shoulder on said sleeve when said sleeve is telescopically mounted on said female contact.