GB2128038A

GB2128038A - Electrical connector

Info

Publication number: GB2128038A
Application number: GB08325562A
Authority: GB
Inventors: John A Morrelli
Original assignee: Automatic Connector Inc
Current assignee: Automatic Connector Inc
Priority date: 1982-09-29
Filing date: 1983-09-23
Publication date: 1984-04-18
Also published as: IT8323042A1; JPS607082A; FR2533768A1; IT8323042A0; DE3334550A1; GB8325562D0; IT1167216B

Abstract

A co-axial electrical connector comprises an outer shell 8 and a body 1 in which is mounted a centre pin 2. A space containing a tapered spring 23 is provided between the shell and the body to permit the centre pin to float radially thus minimising contact breakage during blind mating. <IMAGE>

Description

SPECIFICATION Electrical connector This invention relates to electrical connectors, and more particularly, to electrical connectors used for coaxial cables.

Electrical connectors for coaxial cables are generally formed of two mating parts. These mating parts bring into contact the centre and outer conductors through the electrical connector interconnection. In the process of making such connections a contact is generally made between the centre conductor and the outer conductors, the centre conductor being connected by the insertion of a pin into an appropriate receptacle.

Frequently, during such mating operations, the electrical pin does not seat properly in the receptacle, and the pin can become broken. One way of remedying the situation is to provide significant radial floats so that there is relatively friction-free movement of the pin as it moves into the receptacle, and the alignment between the pin and receptacle can be made without breaking the pin during this connection. Such radial float is generally accomplished by the provision of designed spacings between the shell and body of the connector parts to allow radial floating about a longitudinal axis formed through the centre of the connector pin.Such spacing is formed at various portions between the shell and body which form the connector, and a coiled spring member is generally formed between the shell and body to enhance the radial float movement while permitting flexibility in the connector-receptacle mating assembly.

One of the problems encountered, especially in small connectors, is that the coiled spring can slip in between the recesses formed between the shell and body, and when in this slipped position, the spring becomes locked in the recess preventing free movement between the shell and body. Additionally, it is desired that the centre pin be self-centering even when deflected from its centered position through the radial float feature of the connector. The prior coiled spring assembly does not materially assist the self-centering of the connector pin, and this can lead to damage during connector receptacle connections.

Generally, the connector plugs are loaded from the rear behind the connector pin, and such rear loaded connectors are widely used in the art. When using flexible cable, especially smali sized flexible cable, a preferred connector is identified in United States Patent 4,093,335. That connector is known as a Wedge Lock and is used for flexible cable connections. That connector is loaded from the rear, as are others of similar design, but in some instances, it is not possible to assemble a connector having radial float from the rear. Therefore, it is important to be able to allow and provide a structure to enable front loading of a connector for flexible coaxial cables to be accomplished.

The invention provides an electrical connector having at least a centre pin and an outer electrical contact, the connector comprising a shell and a body with spacing provided between said shell and body to permit said centre pin to radially float with respect to said shell to enhance the connection between said centre pin and a corresponding receptacle without breaking said pin, spring means located between said body and shell and surrounding said body, said spring means being tapered to be narrower at one end and wider at the other, said radial float for said centre pin being provided by a first annular space around said body in the region of said centre pin and a second annular space between said body and said shell at the rear portion of the centre pin assembly, means to form a front seating corner behind said first annular space, said narrower end of said spring bearing against front seating corner, said shell comprising means to form a rear seating corner in front of said second annular space, said wider end of said spring bearing against said rear seating corner, said tapered spring being maintained between said front and rear seating corners as the centre pin radially floats with respect to said shell.

Provision of the tapered spring allows for increased compressive force to be realized which enables self-centering of the connector to be achieved.

Preferred and/or optional features of the invention are set forth in claims 2-7.

The invention will now be more particularly described by way of example, with reference to the accompanying drawings which is a sectional view through one embodiment of a mated plug connector according to the present invention.

The Wedge Lock connector used with the mated plug of this invention is more particularly described in U.S. Patent Nos. 3,107,135 and 4,093,335. These Wedge Lock connectors are employed for flexible coaxial cables.

Reference is made to those patents for further details concerning the construction of the Wedge Lock assemblies and subassemblies.

The Wedge Lock subassembly generally includes a hollow wedge 10 having a substantially rearwardly tapered surface which mates with a complementarily shaped ferrule 11, with the outer connector braid being sandwiched between the wedge 10 and ferrule 11 as wedge nut 12 is tightened in place drawing the ferrule 11 against the wedge 10.

A washer 13 facilitates the rotation of wedge nut 12 during the tightening of the nut drawing the ferrule against the wedge.

The outer conductor or braid is connected through the wedge 10 to the outer contact 3 of the plug subassembly through conductors which are formed of an annular ring 14 abutting against stepdown annular member 15, which itself abuts against a front outer contact 3 which is formed as part of the plug subassembly. In particular, the connector plug includes a body 1 which extends from the front portion of the plug to the rear wedge subassembly, and that body enables the wedge to be connected with the connector plug as described hereinafter.

The centre contact of the coaxial cable fits through the central opening in wedge 10 to a recess 16 formed in the plug subassembly which is in electrical contact with centre contact pin 2. Thus, the centre contact of the coaxial cable is shoved into recess 16 which electrically is connected with centre contact pin 2. At the same time the outer braid or conductor is connected through wedge 10, conductors 14 and 15 to outer contact ring 3. The front face of wedge 10 is provided with radially spaced teeth 17 which are formed of beryllium copper, as is the wedge itself.

Ring shaped connector 14 is formed of stainless steel and is less hard than the beryllium copper, thus enabling enhanced gripping between the teeth 17 of the wedge and the conductor 14 of the contact subassembly.

Afterthe wedge and body subassembly are formed, as well as the centre contact subassembly, a front loading of the connector plug is employed. It should be noted that an insulator 5, generally of a hollow cylindrical shape, is fitted around the centre contact subassembly and separates outer contact 3 from centre contact 2. This insulator extends substantially from the interface between the front portion of the wedge and the accessible front portion of the mating plug subassembly which is to be mated with a corresponding receptacle. The wedge subassembly also includes another insulator 9 also formed of a substantially hollow cylindrical shape which is co-extensive with insulator 5 and provides for a continued insulation between the centre contact recess 16 and outer contact electrical path which comprises wedge 10 and conductors 14 and 15.

Afterthe wedge and centre contact subassembly is assembled, a shell 8 formed of stainless steel of a generally cylindrical shape having a stepdown front portion is loaded onto and bears against a corresponding surface 18 of the body 1. Thereafter, a tapered spring 23 of a generally helical shape which is narrower at the front and wider at the rear is loaded onto a recess or indentation 19 formed in body 1. An annular space 30 is provided between the rear inner surface 20 of shell 8 and the body portion therelocated. Additionally, another annular space 21 is formed between the front portion 22 of the shell and the corresponding portion of the body 1. This space enables significant radial float to be achieved for the connector plug.The spring 23 has its forward portion seated against the front portion of the recess 19, and a ring 4 is inserted over the front portion of the body 1 until the stepdown portion 19, at which time the ring seats against the body in the stepdown portion locking helical tapered spring 23 in place. In this fashion, the front portion of the helical spring 23 nests in the front corner behind the ring 4 and body 1, and the wide rear end the spring rests against an inner corner formed in the shell 8. In this fashion, the spring will rest in place, and the forward portion of the spring cannot get locked into the recess or space between the ring 4 and shell 8 nor can the rear portion of the spring be locked in the space between rear surface 20 of shell 8 and the corresponding body portion.Additionally, the tapered spring exhibits substantially greater compressive strength for the same size as compared with a standard coil spring, and enhanced self-centering of the contact is achieved with this construction.

An O-ring 6 is employed for sealing purposes around conductor 15 to seal the inside of the connector plug subassembly.

The present invention has been described with regard to an illustrative embodiment. The employment of the tapered helical spring in a connector which exhibits radial float characteristics may be combined with any type of connector, whether single pin or multiple pin employing such radial float characteristics. Additionally, the provision of a front loaded connector plug may be employed with a straight connector plug or any angle connector plug as appropriate. Other modifications of the invention will become apparent to those of ordinary skill in the art.

Claims

1. An electrical connector having at least a centre pin and an outer electrical contact, the connector comprising a shell and a body with spacing provided between said shell and body to permit said centre pin to radially float with respect to said shell to enhance the connection between said centre pin and a corresponding receptacle without breaking said pin, spring means located between said body and shell and surrounding said body, said spring means being tapered to be narrower at one end and wider at the other, said radial float for said centre pin being provided by a first annular space around said body in the region of said centre pin and a second annular space between said body and said shell at the rear portion of the centre pin assembly, means to form a front seating corner behind said first annular space, said narrower end of said spring bearing against front seating corner, said shell comprising means to form a rear seating corner in front of said second annular space, said wider end of said spring bearing against said rear seating corner, said tapered spring being maintained between said front and rear seating corners as the centre pin radially floats with respect to said shell.

2. TheconnectorofClaim 1, wherein said tapered spring comprises a helical wire spring.

3. The connector of Claim 1, wherein said tapered spring comprises a telescoped spring member.

4. The connector of any one of the preceding claims, wherein said tapered spring exerts compressive force on said body as the centre pin radially moves with respect to said shell, said tapered spring moving said centre pin to a self-centered position after said centre pin is released from a non-centered position.

5. The connector of any one of the preceding claims, wherein said electrical connector is first loaded, said connector body comprising a first forward annular inward step, said tapered spring being placed between a base surface of said shell and said annular inward step, said body comprising a second annular step being wider and forward of said first annular step, and ring means moving against said tapered spring to lock said tapered spring in place, said ring means being seated in said second annular step.

6. The connector of any one of the preceding claims, wherein said centre pin and outer electrical contact are electrically connected with corresponding conductive elements of a coaxial cable.

7. The connector of Claim 6, wherein said outer electrical contact of said body portion is an electrical connection with the outer braid of said coaxial cable through an annular conductor member, said coaxial cable being connected to a wedge assembly which delivers the centre pin of said coaxial cable and the outer contact of said coaxial cable to the body portion of the connector, said wedge assembly comprising a beryllium copper conductor maintaining the continuity for the outer contact, said beryllium copper conductor comprising teeth for gripping into said body, said annular conductor comprising stainless steel to enhance said gripping action of said teeth.

8. An electrical connector substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.