WO1995028752A1

WO1995028752A1 - Fluid tight through wall connector

Info

Publication number: WO1995028752A1
Application number: PCT/IB1995/000267
Authority: WO
Inventors: Hans-Joachim Zander; Kai Sellien; Franz-Josef Thiel
Original assignee: The Whitaker Corporation
Priority date: 1994-04-19
Filing date: 1995-04-18
Publication date: 1995-10-26
Also published as: GB9407744D0

Abstract

A connector (2) that is receivable within a hole (4) of a wall (6) for transmitting a signal thereacross without leakage from one side of the wall (6) to the other having a signal conductor (10) sealed within a housing (8) that is engageable on both sides of the wall (6) and a seal (18) for cooperating with the housing (8) and the wall (6) to prevent leakage therebetween. The connector (2) characterized in that the seal (18) is inserted into the wall in a first loose position and then displaceable to an engaged position where it is sealed against the housing (8) and the wall (6).

Description

FLUID TIGHT THROUGH WALL CONNECTOR

The present invention relates to a connector for transmitting a signal through a wall, where leakage across the wall must not occur either through the connector or between the connector and the wall.

There are many applications where it is desirable to transfer a signal across a wall that separates different mediums, for example in automotive applications it may be desirable to transmit an electrical signal across the wall of a housing containing a fluid, such as oil, in order to sense characteristics within the housing or to supply signals to components therein. In order to prevent leakage of the fluid from within the housing, the electrical connector must be a sealed unit and be capable of being sealed to the wall of the housing.

The most basic solution to this problem is to pass an electrical wire through a grommet within an opening in the wall. However, sealing is typically poor over time due to ageing of the wire and the grommet and the vibration that occurs. In addition, the use of a wire does not provide for plugability at the wall to enable easy interchangeability or assembly of the components.

United States Patent 4,519,662 attempts to address some of these problems. A body having a central aperture is threaded into a complementary threaded hole in the wall and includes a conductive pin that extends through the aperture which is encapsulated therein by an insulative compound. As the pin extends from either side of the housing, electrical connections can be made therewith. Additionally, an O-ring is seated within a counter-bore located about the complementary threaded hole such that when the housing is fully threaded therein, the O-ring is compressed against the housing and the wall to form a seal therebetween. While this addresses some of the problems presented above, the counter-bore and the portions of the body that engage the O-ring must have a high surface finish that is free of manufacturing defects, such as burrs, in order to ensure a tight seal. Another problem is the time associated with threading the hole, the body and threading the body into the hole during assembly, which add additional assembly costs to the use of a connector of this type. Finally, this structure is particularly unsuited for applications where the wall face that receives the counter-bore is not flat, such as when the face is the internal surface of a cylindrical housing. Not only is the counter-bore difficult to form in such a surface, it would be difficult to thread a body into the threaded aperture so that a seal could be formed therebetween as the features, such as shoulders, on the body are not complementary with the face.

European patent specification 0 331 084 further addresses the problems presented above. An electrical connector is disclosed having a cylindrical block that is housed in a projecting manner within a hole in the wall. The cylindrical block includes a conductor sealed therein and extending therethrough in a fluid tight manner. A lock coupling is connected to the housing to lock the block into the partition. An annular O-ring seal is housed within an annular groove formed on a lateral cylindrical surface of the housing such that the seal interacts with both the housing and the sides of the hole to form a seal therebetween. This connector addresses many of the problems discussed above with the two prior aforementioned connectors for example, such as the connector no longer has to be threaded into the hole in the wall, there are no additional cost associated with creating a counter-bore or threading the hole to receive the connector body. However, as the O-ring is received within an annular groove of the housing body, any burrs, where the hole meets the face of the wall, which the O-ring must pass, can damage the O- ring as it passes during assembly, thereby leading to an ineffective seal. Preparation of the hole and the face of the wall adds time, and therefore expense, to the use of a connector of this type.

It is therefore an object of this invention to provide connector for transmitting a signal from one side of a wall to another in such a manner that the medium on one side of the wall is prevented from leaking to the other side of the wall by way of the connector. It is another object of this invention to accomplish the forgoing in a simple and economical manner.

These objects are accomplished by providing an connector having a housing that is receivable within a hole in the wall, where the housing has an conductor sealed therein that is engageable on both sides of the wall. The housing also includes a seal for cooperating with the housing and the wall to prevent leakage therebetween. The connector further includes a retention member to maintain the housing within the hole of the wall. This particular connector is characterized in that the seal is initially mounted on the housing in a loose position for insertion into the hole and then the seal is displaceable to an engaged position where it seals against the housing and the through walls of the hole. It is an advantage of this invention that with the seal in the loose position, the connector may be inserted into the hole of the wall without regard to causing damage to the seal by burrs or manufacturing imperfections where the side walls of the hole meet the sides of the wall as the seal is not stretched out into its final form where it would abut the side walls of the hole enabling interference with the corners, thereby eliminating the need to preform costly second manufacturing operations to the hole. It is an advantage of one embodiment of this invention, that the seal may be displaceable in response to the movement of the retention member, thereby simplifying the design of the connector. It is another advantage of one embodiment of this invention that a camming surface is provided upon the housing for urging the seal from the loose position to the engaged position. It is still another advantage of an embodiment of this invention, that a contact surface can be formed upon one side of the conductor for detecting an electrical contact, thereby minimizing the number of interconnection points. It is yet another advantage of an embodiment of this invention, that the housing can include a head having a surface that is complementary profiled for seating against one side of the wall, as it is not necessary to rotate the housing in order to insert it within the wall, thereby eliminating the need for counter baring operations.

The invention will now be described by way of reference to the drawings, where; Figure 1 is a partially cut-away side view of an embodiment of an electrical connector this invention received within a wall;

Figure 2 is a partially cut-away side view of another embodiment of the invention showing in phantom form the insertion of the electrical connector into the hole in the wall;

Figure 3 is a partially cut-away side view of the electrical connector shown in Figure 2 sealed within the hole in the wall. Figure 4 is a cut-away side view of yet another embodiment of this invention showing the conductor of the electrical connector formed integrally with a contact surface; and

Figure 5 is a partially cut-away top view of the electrical connector of Figure 4;

With reference first to Figure 1, an electrical connector is shown at 2 that is received within a hole 4 in a wall 6. Wall 6 may be part of a larger enclosure, only some of which is shown in the Figures, which might surround an oil bath, for example. The electrical connector 2 includes a housing 8 that is generally cylindrical in shape having a multitude of diameters, as will be discussed later, and is received within the hole 4 of the wall 6. An electrical conductor 10 is sealably received within the housing 8, advantageously in this embodiment by overmoulding the housing 8 about the conductor 10, although other processes may be used. In the embodiment of Figure 1, the conductor 10 is adapted with tab terminals 12 on each end that are electrically engageable by a mating connector 14 or another electrical component (not shown) . The housing 8 is retained within the hole 4 of the wall 6 by retention member 16. A seal 18, shown generally in this embodiment as what is commercially known as an O-ring type seal, cooperates between the housing 8 and the wall 6 within hole 4 to prevent leakage therebetween.

As round holes 4 are most easily formed in the wall 6 by such processes as casting, moulding, drilling or stamping, typically the hole 4 will be as described above, cylindrical in nature. In order to prevent the housing 8 from passing completely through the hole 4 in the wall 6, a head 20 is provided on one side of the housing 8. As not all applications involve a wall 6 that has a planar surface, the surface of the head 20 that abuts the wall 6 may complimentarily profiled to seat against the wall 6, as for example the configuration shown in Figure 5. A shoulder 22 extends from the head 20 and is sized to be received within the hole 4. It may be desirable to provide an under-cut where the shoulder 22 and head 20 meet to accommodate any burrs or sharp edges present where the hole 4 breaks out of the wall 6. Stepped down from the shoulder 22 is a seal seat portion 24 whereupon the seal 18 is seated when in the engaged position, as will be described below. Typically, the diameter of this seal seat portion 24 would be such that the seal 18 is closely received thereupon. A camming portion 26 extends between the seal seat portion 24 and a reduced diameter front portion 28 where the seal 18 is placed when the housing 8 is inserted into the hole 4 in wall 6, best shown in Figure 2. A guiding extension 30 extends from the reduced diameter front portion 28 through the wall 6. The guiding extension 30 will cooperate with the retention member 16 as will be further described below to retain the connector 2. In order to retain the seal 18 at the reduced diameter front portion 28 while the housing 8 is inserted into the wall 6, it is possible to form the reduced diameter front portion 28 of a slightly smaller size than guiding extension 30, thereby forming a slight depression for retaining the seal 18. A recess 32 having a back-up stop 34 is provided opposite head 20 to cooperate with the retention member 16, as will be further described below, to retain the housing 8 within the wall 6 in a sealed manner.

The longitudinal dimensions of these features are selected such that the seal seat portion 24 and the reduced diameter front portion 28, with the camming portion 26 therebetween, are within hole 4 inward of the outer surfaces of the wall 6. This assures that as the seal 18 is moved from the reduced diameter front portion 28 to the seal seat portion 24, there is no interference with burrs or manufacturing imperfections that might exist where the hole 4 passes through either side of wall 6. Typically, with the conventional manufacturing processes like those listed above, it is possible to produce a hole having side walls of acceptable dimensions and surface finish for sealing therewith. The difficulty occurs where the hole enters and breaks out of the wall. At this location it is common for burrs, casting flash, or other imperfections to be left behind. By camming the seal 18 to its sealed position only when it is within the hole 4, seal 18 does not come into contact with such obstructions while in a loaded or stretched state.

The retention member 16 is matable with the housing 8 in order to maintain the housing 8 within wall 6. The retention member 16 includes a front face 36 constructed to cooperate with the seal 18 in order to displace the seal 18 into a loaded state by moving the seal 18 from the reduced diameter front portion 28 over the camming portion 26 to the seal seat portion 24, as will be described below. A nose 38 extends rearward from the front face 36 and is sized to be received within the hole 4 so that an adjoining shoulder 40 abuts the opposite side of the wall 6 than is engaged by the head 20 of the housing 8, thereby mechanically captivating the connector 2 about the wall 6 with minimal play therebetween. A body portion 42 is incorporated into the retention member 16 to provide surfaces that would be gripable by an installation tool or fingers, in order to seat the retention member 16 upon the housing 8. Extending rearwardly therefrom are a plurality of resilient latching fingers 44 that have inwardly directed barbs 46 that are deflectable over the housing 8, such that the barbs 46 are received within recess 32 of the housing 8 so that stop surface 48 on the latching fingers 44 abuts the back-up stop 34 of the recess 32 to prevent disengagement. The retention member 16 has a primary inner diameter 50 that is slidably received over guiding extension 30. Note that this inner diameter 50 may be profiled where it meets the front face 36 to be complementary with the camming portion 26.

With reference now to Figure 2 and Figure 3, assembly of a second embodiment of a connector 100 according to the present invention to a wall 106 will be described. The electrical connector 100 of these Figures is an alternative embodiment of the one described in Figure 1. In this embodiment, the retention member 116 is threadably received upon housing 108 by way of complementary threads 52 formed in the respective members, as opposed to the simple linear displacement described above. The housing 108, shown as a phantom representation in Figure 2, with the seal 118 in a loose position at the reduced diameter front portion 128 is inserted into the hole 104 from one side thereof until the head 120 abuts the wall 106. As shown in this position, the seal 118 is within the wall 106 without substantial interference therebetween. As the seal 118 is loosely received upon the housing 108 as the housing is inserted into the wall 106, any burrs or manufacturing imperfections where the hole extends through the wall 106 do not interfere with the seal 118 and, therefore, cannot damage the seal 118. Once the housing 108 and seal 118 have been inserted within the wall 106, the retention member 116 is fitted over the guiding e- :.ension 30 of the housing 106. In the embodiment of the invention shown in Figures 2 and 3 as connector 100, the retention member 116 is threadably advanced such that the front face 136 of the retention member comes into contact with the loosely fitting seal 118 at the reduced diameter front portion 128. Further threading advancement of the retention member 116 causes the face 136 to press against the seal 118 and displace the seal 118 upon and over camming portion 126 into position against the shoulder 122. The seal 118 now forms essentially 4-point continuous contact with the shoulder 122, the seal seat portion 124, the wall 106 and the front face 136 of the retention member 116, thereby forming an effective seal to prevent leakage from one side of the wall 106 to the other. In the case of the embodiment shown in Figure 1, the retention member 16 is pressed over the guiding extension 30 such that the front face 36 comes into contact with the seal 18 that is displaced to seal seat portion 24 when the inwardly directed barbs 46 of latching fingers 44 are received within recess 32. Where back-up of the retention member 16 due to the resilience of the seal 18 is prevented by cooperation of the back-up stop 34 and the stop surface 48.

In yet another embodiment of the invention shown as connector 202 in Figure 4 and Figure 5, the inner diameter of retention member 216 is shortened and passes over resilient barbs 254 on the housing 208 to retain the seal 218 in the seal seat portion 224. In all of the alternative embodiments described above, the seal 18 118, 218 is initially placed in the hole 4, 104, 204 while loosely received upon the housing 8, 108, 208 and displaced, once therein, to an engaged position 60 form the seal between the connector 2, 102, 202 and the wall 6, 106, 206. As shown in Figure 1, it is possible to adapt the conductor 10 for interconnection with an electrical connector 14 that is further connected to an electrical conductor 60, such as an insulated wire. The opposite end of this conductor may then be attached to a component within the enclosure, as it is not necessary for the housing 14 to rotate during assembly. In the example illustrated in Figure 1, this component is a contact 62 for sensing make-and-break electrical interconnection with contact point 64 on another component 66 that is free to move up and down, thereby bringing the contact point 64 into and out of electrical engagement with contact 62.

In the embodiment shown in Figures 4 and 5, the conductor 60 of Figure 1 is replaced by forming the conductor 210 of the connector 202 as a lead frame such that it is integral with the contact 262. Additionally, as the other component 266 containing the contact point 264 may rotate as illustrated by arrow A in addition to translating up and down, it may be desirable to enhance the contact face 268 with grooves 270 that extend thereacross in order to establish an intermittent contact pattern, such that any contaminants within the enclosure will not defeat effective electrical interconnection. Advantageously then, the present invention provides a through wall connector structure where a housing is sealably received in a hole in a wall where once seated therein a seal carried upon the housing is displaceable to a sealing position. The present invention protects the seal from damage during assembly and minimizes the manufacturing costs associated with protrusion of the hole. As the housing does not have to rotate once inserted into the wall, the present invention is especially suitable for walls having irregular surfaces and the reduction of components as a lead frame may be incorporated therewith.

Claims

1. A connector (2,100,200) receivable within a hole (4) in a wall (6) for transmitting a signal from one side of the wall (6) to another without leakage thereacross, comprising a housing (8,108,208) receivable within the hole (4) and having a conductor (10,210) sealed therein transmissively engageable on both sides of the wall, said housing (8,108,208) having a seal (18,118,218) thereupon cooperating with the housing (8,108,208) and the wall (6) to prevent leakage therebetween, and a retention member (16,116,216) to maintain the housing (8,108,208) within the hole (4) ; characterized in that when the housing (8,108,208) is inserted into the hole (4), the seal (18,118,218) is in a loose position and is then displaceable to an engaged position where it is sealed against the housing (8,108,208) and the through walls of the hole (4) .

2. The connector of claim 1, further characterized in that the seal (18,118,218) is displaced in response to movement of the retention member (16,116,216).

3. The connector of claim 2, further characterized in that the retention member (116) is threadably displaceable.

4. The connector of claim 2, further characterized in that the retention member (16,216) is linearly displaceable.

5. The connector of any one of the preceding claims, further characterized in that the housing (18,118,218) includes a reduced front portion (28) upon which the seal (18) is located in the loose first position, a larger seal seat portion (24) where the seal (18) is located in the engaged position and a camming surface (26) therebetween over which the seal (18) is displaced.

6. The connector of any one of claims 1-4, further characterized in that the conductor (210) is formed on one end as a lead frame having a contact surface (262) thereupon.

7. The connector of any one of claims 1-4, further characterized in that the conductor (10) is adapted on one end (12) for removable engagement with an electrical connector (14) .

8. The connector of claim 6, further characterized in that the contact surface (262) is an annular ring.

9. The connector of claim 8, further characterized in that the contact surface (262) includes a groove (270) extending thereacross.

10. The connector of claim 1, further characterized in that the housing (18) includes a head (20) complementarily profiled to seat against an irregular side of the wall (6).

11. The connector of claim 5, further characterized in that the housing (8) includes a recess (32) and a back-up stop (34) and the retention member includes a resilient latching finger (44) having a barb (46) thereupon, where the barb (46) is receivable in the recess (32) in an abutting relation with the back-up stop (34) at the second sealed position, whereby disengagement is prevented.

12. The connector of claim 5, further characterized in that the housing (208) includes resi lent barbs (254) overwhich the retention member (216) passes and engages for retention therewith.

13. A connector receivable (2,100,200) within a hole (4) in a wall (6) for transmitting a signal from one side of the wall to another without leakage thereacross, comprising a housing (8,118,218) having a seal seat portion (24) receivable within the hole (4) and a head (20) at one end that seats against one side of the wall (6) when the housing (8) is inserted into the hole (4) , a signal conductor (10) spanning said housing (8) and being transmissively engageable on both sides of the wall (6) when the housing (8) is received therein, and a seal (18) upon the seal seat portion (24) that sealably engages the housing (8) and the wall (6) when the housing (8) is received therein, and a retention member (16) that maintains the housing (8) within the hole (4) , where the housing (8) includes a reduced front portion (28) that is interconnected to the seal seat portion (24) by a camming surface (26) ; the seal (18) being loosely received upon the reduced first diameter portion (24) when the connector (8) is inserted into the hole (4) and thereafter displaceable over the camming surface (26) to the seal seat portion (24) to form the seal between the wall (6) and the housing (8) .

14. The connector of claim 13, wherein the conductor (10) is for transmitting electrical signals.

15. The connector of claim 13 or claim 14, wherein the retention member (16) includes a front face (36) that abuts the seal (18) for displacing the seal (18) as the retention member (16) is mated with the housing (18) to captivate the wall (6) therebetween.

16. The connector of claim 15, wherein the retention member (16) is displaceable along the housing in a linear manner and snap fits thereto.

17. The connector of claim 15, wherein the retention member (16) is threadable to the housing.

18. The connector of claim 13, wherein the seal seat is along the camming portion 126.

19. The connector of claim 13, wherein the reduced diameter front portion (28) where the seal is seated during insertion into the wall is an undercut.

20. An electrical connector (2,100,200) for insertion into a wall (6) and being sealable therewith comprising a housing (8,108,208) having a conductor (10,210) extending therethrough, where the housing (8,108,208) has an outer surface including a front portion (28,128) and a seat portion (24), the front portion (28,128) being of reduced size compared to the seat portion (24) where a camming surface (26,126) extends therebetween, the housing (8,108,208) being insertable from one side of the wall (6) to a shoulder (20,220) thereupon, a seal (18,118,218) carried upon the housing (8,108,208) during insertion into the wall (6) along the front portion (28,128), and a retention member (16,116,216) insertable onto the housing (8,108,208) from the other side of the wall (6) and having a front face (36) for displacing the seal (18,118,218) from the front portion (28,128) over the camming surface (26,126) to the seat (24,124) such that the seal (18,118,218) is sealed with the through walls of the wall (6) where a shoulder (40) upon the retention member (16,116,216) abuts the wall (6) such that the wall (6) is captivated between the two shoulders (20,40).