GB2061027A - Electrical connectors - Google Patents

Abstract

To provide an environmental seal in an electrical connector, that connector has a peripheral seal comprising a hollow resilient sealing ring (50) mounted in a groove (52) in one connector member, and an annular rigid lip (48) on the mating connector member. When the connector members are mated, the lip (48) indents the forward wall of the sealing ring (50) into an inverted configuration so that the wall bears against the inner and outer surfaces and front edge of the lip. The sealing ring has transverse ribs (66) on its surface facing the rigid lip, which ribs respectively engage the inner and outer surfaces and the front edge of the lip. <IMAGE>

Description

SPECIFICATION Electrical connectors This invention relates to electrical connectors, and especially to a seal which provides environmental sealing for a pair of mated connector members.

Reference is made to U.S. Patent No. 3,621,448 (Arnold et al) which describes the shortcomings of prior art peripheral seals, and discloses and claims an improved seal which allows sealing of mating connector members over a wide range of mating conditions. The Arnold et al seal comprises an elastomeric ring having a rear portion secured to an outer surface of one connector member, a front portion which engages the mating connector member, and an intermediate portion which folds in an accordian fashion as the connector members are drawn together. While the accordian seal is suitable for most appiications, some applications need greater sealing surfaces and a wider axial tolerance range of reliable sealing. For example, prior art seals are not always reliable when incorporated in electrical connectors having spring-loaded coupling devices, such as spring-loaded bayonet coupling rings.

If the plug connector member of such a connector is subjected to side loading, such as occurs when the receptacle is fixed to a panel and the conductors connected to the plug contacts are pulled laterally, the plug cocks or skews relative to the receptacle.

This may cause the peripheral seal to open at one side because the front faces of the plug and receptacle between which the seal is mounted are no longer parallel.

It is an object of this invention to provide an improved peripheral seal for an electrical connector which provides low force, reliable sealing over a wide axial tolerance range, even when one of the connector members of the connector is skewed due to side loading.

According to the present invention, there is provided an electrical connector, including first and second mating connector members; a peripheral sealing element on said first connector member, which element has a hollow configuration with a resilient, deformable forward wall facing the second connector member; and a rigid lip on said second connector member positioned to engage the forward wall of said sealing element upon mating of the connector members, wherein during said mating said lip indents said forward wall into an inverted configuration so that said wall bears against the inner and outer surfaces and front edge of the lip.

The seal may be effected with only a low mating force between the connector members. Also, a large surface area of sealing engagement between the resilient sealing element and the lip is achieved, providing reliable sealing between the mating members. Further, a substantial axial deformation of the seal occurs due to its hollow configuration, which ensures reliable sealing of the connector members over a wide axial tolerance range and in spite of the fact that a side load might be applied to one of such members.

An embodiment of the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a partial longitudinal section through an electrical connector using a sealing arrangement embodying the present invention, the connector members being shown in their fully mated condition; Figure 2 is a perspective view of the resilient sealing element used in the connector of Figure 1; Figure 3 is an enlarged, fragmentary, section showing the sealing lip and sealing element of Figure 2 disengaged prior to full mating of the connector members, and Figure 4 is a view similar to Figure 3 but showing the sealing lip and sealing element fully engaged as occurs when the mating connector members afe completely mated.

Figure 1 shows an electrical connector, generally designated 10, which incorporates the novel peripheral sealing arrangement, and which comprises a plug 12 and mating receptacle 14. The shell 16 of the plug contains a two-piece insulator 18 having socket contacts 20 mounted therein, two being shown for purposes of illustration. The insulator 18 is retained in the shell 16 by a retaining ring 22.

The shell 24 of the receptacle member 14 contains a two-piece insulator 26 having pin contacts 28 mounted therein which are positioned to engage with the socket contacts 20 when the connector members are mated. The insulator 26 is retained in the shell 24 by a retaining ring 30. A flange 32 is formed on the shell 24 to facilitate mounting of the receptacle connector member on a panel (not shown).

The plug and receptacle members are coupled by a bayonet coupling ring 34 rotatably mounted on the shell 16 of the plug member 12. In a conventional manner, the slot 36 in the coupling ring 34 engages a radially outwardly extending post 38 on the shell 24.

A wave spring 40 between a flange 42 on shell 16 and a ring 44 on the rear of the coupling ring 34 biases the ring rearwardly so that the coupling arrangement is spring loaded.

The peripheral sealing arrangement generally designated 46, comprises a rigid annular sealing lip 48 formed on the front of the plug shell 16 and an elastomeric annular sealing element 50, see Figures 2to4.

The sealing element is mounted in an annular groove 52 formed in a forwardly-facing surface 54 of the shell 24 opposite the sealing lip 48. The sealing element 50 is frictionally mounted in the groove 52, and it has a generally U-shaped cross-section providing a generally semi-cylindrical forward wall 56, an outer cylindrical wall 58 and an inner cylindrical wall 60. The forward wall is relatively thin so as to be resilient and readily deformable. The outer surface of the wall 58 and the inner surface of the wall 60 conform to the outer and inner surfaces of the groove 52 to provide a relatively large sealing surface between the sealing element and the shell 24. The rear portions 62 and 64 of the walls 58 and 60 of the sealing elements are thicker than the forward wall 56 thereof to enhance the frictional retention of the element in the groove 52.Thus, it will be seen that the sealing element is hollow and provides a resilient, deformable curved forward wall adjacent to the annular lip 48 on the shell 16.

Preferably, radially spaced annular sealing ribs 66 are formed on the front surface of the forward wall 56, seven of such ribs being shown by way of example.

When the plug and receptable connector members l2and 14are mated,thelip48onthe plug shell 16 engages the forward wall 56 of the sealing element 50, indenting the wall into an inverted configuration, as seen in Figure 4, whereby the wall bears against the inner and outer surfaces 68 and 70, and arcuate forward edge 72 of the sealing lip. The number and location of the ribs 66 on the sealing element are so selected that at least one rib engages the inner surface, the outer surface and front edge, respectively, of the lip. Thus, a plurality of sealing surfaces is provided between the lip 48 and the sealing element 50.

Because of the hollow configuration of the sealing element and the narrowness of the lip 48 relative to the sealing element, the sealing element may be subjected to a relatively long axial deformation, thus accommodating a wide axial tolerance range between the mating connector members, while maintaining a reliable seal. Furthermore, the sealing arrangement may be achieved with a relatively low force. Since all sealing forces are directed against the hollow element 50, the element requires no bonding or housing undercuts to retain its position in the shell 24.

While the sealing lip 48 and element 50 are of circular configuration, it is believed that the seal will function in an identical manner if formed in a rectangular configuration to accommodate connector shells of "D" configuration. It would also be possible for the sealing element to be closed, rather than open to the rear as is the element 50 described herein. Other modifications of the seal within the scope of the present invention will be apparent to those skilled in the art.

Claims (11)

1. An electrical connector, including first and second mating connector members; a peripheral sealing element on said first connector member, which element has a hollow configuration with a resilient, deformable forward wall facing the second connector member; and a rigid lip on said second connector member positioned to engage the forward wall of said sealing element upon mating of the connector members, wherein during said mating said lip indents said forward wall into an inverted configuration so that said wall bears against the inner and outer surfaces and front edge of the lip.

2. A connector as claimed in claim 1, wherein said forward wall has a generally semi-cylindrical cross-section.

3. A connector as claimed in claim 1 or 2, wherein said forward wall embodies radially spaced annular sealing ribs positioned to engage said lip.

4. A connector as claimed in claim 3, wherein said ribs are so located on said forward wall that when the wall is indented by said lip ones of said ribs will engage said inner surface, front edge and outer surface of said lip, respectively.

5. A connector as claimed in claim 1,2,3 or 4, wherein the front edge of said lip has an arcuate configuration.

6. A connector as claimed in claim 1, wherein said sealing element has a generally U-shaped cross-section defining said forward wall of arcuate configuration and inner and outer generally cylindrical walls.

7. A connector as claimed in claim 6, wherein said first connector member has a continuous groove with said sealing element frictionally mounted in said grooves; and wherein the rear portions of said inner and outer walls are thicker than the remainder of the sealing element to enhance the frictional retention of the element in said groove.

8. An electrical connector including first and second mating connector members each having a shell surrounding an insulator containing electrical contacts, wherein said first connector member shell has a forwardly facing surface with an annular groove in that surface; wherein an annular sealing element is mounted in said groove, which sealing element is hollow with a resilient, deformable forward wall of generally semi-cylindrical crosssection, wherein said forward wall embodies radially spaced annular sealing ribs; wherein said second connector member shell embodies a rigid annular lip postioned to engage the forward wall of said sealing element upon mating of said connector members, and wherein during said mating said lip indents said forward wall into an inverted configuration whereby said wall bears against the inner and outer surfaces and front edge of said lip.

9. An electrical connector member including a shell surrounding an insulator containing electrical contacts; and a resilient, compressible annular sealing element mounted on said shell; said sealing element having a hollow configuration with a forward wail adapted to be indented into an inverted configuration when engaged by an annular rigid lip on a mating connector member.

10. A connector member as claimed in claim 9, wherein said forward wall has radially spaced annu larsealing ribs.

11. An electrical connector substantially as described with reference to the accompanying drawings.