GB2192316A - Electrical connector - Google Patents

Description

SPECIFICATION Electricalconnector The invention relates to an underwater electrical connector comprising male and female parts which are broughttogetherto make an electrical connection.

Underwater electrical connectors are known in which the female part has an electrical contact disposed within a closecichamberfilled with an insulating grease oroiftoprovide a protected area around the contact where aconnection is to be made.

It has been proposed in U.S. Patent No. 3,729,699 to provide the oil filled chamberwith an opening which is sealed by a spring biased sIidableshuttlepiston arranged to be pushed back by engagement of a projecting male contact pin with the piston. By thus providing a shuttle piston, very little, if any, distortion ofthe opening is required, and the opening can be quite large to permit large pin diametersforheavy currentand/ora multi-service arrangement such as a coaxial connection.

The opening ofthe chamber is closed either bythe shuttle piston in the unmated condition ofthe connectoror bythe male contactpin when the male and female parts of the connector are brought together. A seal forthe opening is provided in the form of a pair of spaced O-rings for engaging the shuttle piston orthe contact pin, depending on which ofthese extends through the opening. With this arrangement there is a risk of deterioration of the seal which may result in wateror contaminants entering the chamber wheretheelectrical connection is made.

According to the invention there is provided an underwater electrical connector comprising maie and female parts, the male part having a contact pin and the female part having contact means within or inwardly of a chamber containing electrically insulating media, the chamber being provided with an opening normally closed in sealing manner by a resiliently biased shuttle piston which extends through the opening and is arranged to be engaged and urged back by the contact pin during insertion thereofto cause an electrical connectionto be made with the contact means of the female part, wherein the female part has first and second closed chambers containing electrically insulating; media and each provided with a respective opening, the openings being aligned and normally sealed by the shuttle piston extending therethroughPthesecond chamber being located within or i nwardiyofthe first chamber and the contact means being located within or inwardly of the second chamber.

With such an arrangement, iffor example the quality of the seal of the fi rst chamber opening deteriorates and allows entry of water or contaminants, then the provision ofa second closed chamber located within or inwardly ofthe first ensures thatthe reg ion where the contuetmeans is located is not contaminated.Thusa reiable, electrically insulated electrical connection can be ensured.The electrical insulating media in the chambers will generally be a dielectricfluid such as oil, grease orthe like The electrical intergrity of the two chamber connector can be further improved by providing athird chamber containing electrical insulating media and located within or inwardly ofthe second chamber, the third chamber having an opening aligned with the other openings and normally sealed bythe shuttle piston extending therethrough,the contact means being located within the third chamber. In the event of breakdown ofthe sealing ofthe openings to the first and second chambers, then the third chamber provides further protection for the region where the electrical connection is made.

The shuttle piston might have a conducting portion which is engaged by the contact pin and which engages the contact means within or inwardly of the second chamberwhen the piston is pushed back, therebycompletingthe electrical connection. However, the shuttle piston is preferably formed of electrical lyinsulating material and extends through afemale contact socket located within or inwardly ofthe second chamber, wherebythe electrical connection is made bythe contact pin pushing backthe shuttle piston to be received and directly engaged by the contact socket. This arrangement, whole providing the advantages of a shuttle piston referred to above, avoids the need for a double electrical connection i.e.

that between the contact pin and the piston and that between the piston and the female contact means.

Since the contact socket is provided within a chamber containing electrically insulating media, it can be "live" prior to and during mating ofthe male and female parts oftheconnector.

It is desirable thatthe connector can withstand high pressures so that it can be used underwater at depth.

Thus, the connectormayinclude means for effecting balancing ofthe media pressure in the respective chambers relative to the pressure outside the connector. This can be done by making the chambers containing insulating media variable in volume so as to adaptto pressure changes and thus inhibitthe entry ofwaterthrough the respective openings. This may be achieved by means of a piston orthe like, but preferably each chamber has a wall formed at least partly of a flexible membrane arranged to permit variation ofthe respective chamber volume. The flexible membrane may be formed as part of the same memberwhich normallysealsthe chamber opening, or it may be provided separately at a convenient location.

The normally sealed openings ofthefirst and second chambers are generally formed in respective frontwallsthereof, and in one preferred embodiment each chamber has a flexible membrane in a sidewall thereof, the membrane ofthe second chamber being laterally inwardly spaced from the side wall of the first chamber. Thus, in this embodiment the second chamber is defined within the first. In this arrange ment the first chamber membrane is arranged to be exposed to the pressure of ambient water while the second chamber membrane is exposed to the presssure of media in the first chamber. If a third chamber is provided this can also have a flexible membrane in a side wall thereof laterally inwardly spaced from the second chamber side wall.

In another embodiment in which the normally sealed openings are formed in respective front walls ofthe chambers, the chambers share a common outer side wall, the second chamber being located inwardly ofthefirst. Aflexible membranefor each chamber mightthen be provided in the outerwall, each membrane being exposedtothepresureofambient water, but preferablytheflexible membranes are provided in the respective front walls.

The male part ofthe connector may include a slidably mounted wiper seal engaging the contact pin and resiliently biased towards the contact end thereof, the seal being arranged tobe moved back overthe pin during mating ofthemale and female parts. The wiper seal may,forexample, be mounted by a slidable piston which defines the forward end of a chamberfor the contact pin.

The male part ofthe connector may be provided with a single contact pin or itmay have a plurality of pins with the female part having the same number of contacts means. Prefera blyfo u or more contact pins are provided, and they mightfor example be uniformly spaced around the central longitudinal axisofthe connector. If a third chamber is provided it might enclose all the female contact means collectively, but preferably each contact means corresponding to a respective contact pin is separately enclosed by an individual third chamber.

Certain preferred embodiment of the invention will now be described byway of example and with reference to the accompanying drawings in which: Fig. lisa partly sectioned side elevation ofthe male part of an electrical connector; Fig. 2 is a partly sectioned side elevation ofthe female partoftheconnector; Fig. 3 is a partsection on the lines 3-3 of Figure 2; Fig. 4 is a section-through the male part of a second embodiment of electrical connector; and Fig. 5 is a section through the female part of the connector of Figure 4.

The electrical connector basically comprises female part 1 to be connected underwater with a female part 2. Referringfirstlyto Figure 1,the male part1 includesfour projecting contactpins3 bonded to an insert4 held by a retaining ring 5 in a connectorsocket 6. The connector socket may be moulded or it may be fabricated e.g. by machining to the correct size and shape. The insert 4, which may be formed of epoxy resin or other suitable insulating material, is correctly located by means of a key and key-way 8 at its rear end and is sealed to the connector socket 6 by a pair of insert 0-rings 9. The connector socket is provided with three bulkhead seals 10 to ensure sealed engagement with e bulkhead.At its forward end the connector socket has an outershroud 11 surrounding the four contact pins and having a key-way 12 for accurate mating with the nose ofthefemale connector part 2.

Slots 13 are provided for displacementofwater as the outer shroud 11 receives the nose ofthe female part.

The contact pins are each provided at the rear end with a solder cup 1 4for connection with a respective conductorand atthe front end with a cone-shaped recess 15 for positive engagement with a corresponding projection ofthefemale part during mating.

Referring to Figures 2 and 3,thefemale part2 ofthe connector includes a connector plug 1 6to which is secured the nose 17 having a key 18 for engagement with thekey-way 12 ofthe male part during mating.

Other location/guidance arrangements could be used.

Similarly to the arrangement of the connector socket 6, the connector plug 16 is provided with an e.g. epoxy resin insert 19 located by a key and key-way 20 and held bya retaining ring 21, the insert being sealed to the connector plug bya pair of O-rings 22. Fourtubular contact sockets 23 are bonded within the insert 19 and are each provided at the 'rear end with a solder cup 25 for connection with a respective conductor26 of a cable 27. Alternatively, a crinilped or othertype of connection might be used. Thconnectien is encased in a polyurethane moulding 5d'ssonded'tc:theconnec- tor plug 16, the insert 19 and the cable 27.Thefemale part ofthe connector could also be proví dedS aform which is more readily installable orssite.

Attheirforward ends the tubular contact sockets 23 project into the connector plug nose 17. Withinthe nose 17 are defined a first outer chamber 28, a second chamber 29, and four individual third or inner chambers 30 each enclosing the projecting end of a respective contact socket 23. All the chambers are filled with insulating media such as a dielectricfluid e.g. oil, grease orthe like. The first chamber 28 has an annular outerwall comprising a flexible membrane 31 the outer surface of which is vented to the outside by a pressure compensating vent hole 32.This ensures thatwhen the connector is submerged and is subject to increasing pressures, the membrane deflects inwardlyto decrease the volume ofthe chamber and so balance the pressure. In thisway any tendency for waterfrom the outside to enter the chamber is reduced. An annular space 49 around the outside of the membrane 31 allows dielectricfluid displacement when the contact pins enterthe chambers during mating. The second chamber 29 is enclosed within the outer chamber 28 and is similarly provided with an annularflexible membrane 33. The individual inner chambers 30 also each have an annularflexible membrane 34, each carried by lantern type supports 35 projecting from the insert 19.

The first or outer chamber 28 is closed by a front plate 36 which has rearwardly projecting lugs37 supporting a front plate 38 of the second chamber. The front plate 39 of each inner chamber 30 is supported by the lantern supports 35. The front plates36,38 and 39 ofthe respective chambers are respectively provided with openings 40,41 and 42, each havingian annular seal 43,44 and 45. Referringita the arranged ment associated with just one of thefaur iniRer chambers 30, a slidable shuttle pistonl46ìextenuds through the three aligned opening,sAO,4ii and 42 so as to close the chambers. In fact, thaannuJrseal 45 of the inner chamber is an O-nngwhicti has a slight clearance from the shuttle pin to reduce drag thereon, although the contact pin 3 is of larger diameter so that the seal 45 forms a close fit on the pin during mating.

The shuttle pin is formed of an insulating material and is forwardly biased bya spring 47 retained within the contact socket 23. The front ofthe shuttle piston is formed as a cone-shaped projection 48forpositive engagementwiththecorrespondinglyshaped recess 15 ofthe male connector part.

To make the connection between the male and female parts of the connectorthe plug nose 17 is inserted into the outer shroud 11 while being guided bythe mating key 18 and key-way 12. Each of the four contact pins 3 engages a corresponding shuttle piston 46 and pushes it back againsttheforce ofthe spring 47. The pin passes successively th rough the three aligned openings 40,41 and 42 to be received in the contactsocket23andtherebyto complete the electrical connection.

Figures 4 and 5 respectively show male and female parts 101 and 102 of a second electrical connector.

Referring firstly to Figure 4the male part 101 includes a single contact pin 103 projecting from an insert 104 and surrounded by an outer shroud 111 which defines a contact pin chamber 150. Theforward end of the chamber 150 is closed by a piston 151 split into two parts which receive therebetween a wiper seal 152 engaging the outside ofthe contact pin. The piston is urged by a spring 153 to a forward position in which a radial projection 154 ofthe piston engages an abutment ring 155 secured on the end ofthe shroud 111 The piston is located inthisforward position when the connector is in the unmated condition and the major length ofthe contact pin is then protected.

When the male part 101 is mated with the female part 502the piston 151 is pushed rearwardly and carries thewiperseal 152 which slides axially along the surfaceofthe contact pin. On decoupling the connector, the spring 1 S3ensures that the piston and wiper seal return to theforwa rd position, so that the contact pin chamber 150 is protected at all times from the entry of debris.

Referring to Figure 5, the female connector part 102 includesaplug nose 117 in which is mounted a tubular contactsocket 123 having a slidable shuttle piston 146 extending axiallythereth rou g h, as in the embodiment of Figures 1 to 3. Within the plug nose 117 are defined afirstouterchamber 128 and a second, inner chamber 129 which enclosesthe contact socket 123.

Theforvvard wall ofthe outer chamber comprises a one-piece closure member 156 having a central axial opening 157'through which the shuttle piston 146 extends. The closure member 156 is formed of a flexible material and has an inner ring seal 158 defining the opening 157 and an outer ring seal 159 in sealed engagement with the inside surface ofthe plug nose 117 The ring seals 158 and 159 are connected together by an integral, relativelythin,flexible membrane 160 oftheclosure member which isarrangedto project rearwardly into the outer chamber 128 and to flex so asto allowvolume changes thereof, similarly to membrane 31 ofthefirst embodiment.The closure member 156 is retained in position on its forward side by a nut 161 having axial passages therethrough to communicatetheoutside of membrane 160with ambientwater pressure, and on its rear side by a cage support 162 which also serves to supportthe membrane.

A second closure member 163 separates the outer and innerchambers 128and 129.The member 163 has an inner ring seal 164 defining an opening 165 forthe shuttle piston, an outer ring seal 166 in sealed engagement with the inside surface ofthe plug nose 1 17,and an integral flexible membrane 167 connecting the ring seals together. The closure member is retained on its forward side by a washer 168 having axial holes therethrough to communicate the mem- brane 167 with the pressurein the outer chamber 128, and on its rear side by a cage support 169 which abuts againsttheforward end of a sleeve 170 disposed inside the plug nose 117.

To make the connection between the male and female pa its 101 and l02oftheconnectortheplug nose 117 is inserted onto the outer sh roud 111.The piston 151 ofthe male part is pushed back bythe nose 117 and the contact pin 103 pushes back the shuttle piston 146 to pass successively through the opening 157to the outer chamber and the opening 165 to the inner chamber. The contact pin is received in the contactsocket 123 to completethe electrical connec- tion within the inner chamber.

Although the embodiment of Figures 4 and 5 has only one pin and socket, a plurality ofsuch of such pins and sockets could be provided in a connector.

Itisto be notedthatin both embodiments the various chambers containing electrically insulating media are separate and sealed from each other, the only communication between adjacent chambers being provided by the openings through which either the shuttle piston passes in the unmated condition of the connector orthe contact pin passes when the male and female parts ofthe connector are brought together.

Modifications to the broad aspects and the specific embodiment ofthe invention may be apparentto a person skilled in the art and it is intended thatthis disclosure should extend to any such modifications.

Claims (9)

1. An underwater electrical connector comprising male and female parts, the male part having a contact pin and the female part having contact means within or inwardly of a chamber containing electrically insulating media, the chamber being provided with an opening normally closed in sealing manner by a resiliently biased shuttle piston which extends through the opening and is arranged to be engaged and urged back bythe contact pin during insertion thereof to cause an electrical connection to be made with the contact means ofthefemale part, wherein the female part hasfirstand second closed chambers containing electrically insulating media and each provided with a respective opening, the openings being aligned and normally sealed by the shuttle piston extending therethrough, the second chamber being located within or inwardly ofthefirst chamber and the contact means being located within or inwardlyofthe second chamber.

2. Aconnectorasclaimed in claim 1, wherein the shuttle piston is formed of electrically insulating material and extends th rough a female contact socket located within or inwardly ofthe second chamber, wherebytheelectrical connection is made by the contact pin pushing back the shuttle piston to be received and directly engaged by the contact socket

3. Aconnectoras claimed in claim 1 or2, including meansforeffecting balancing of the media pressure in the respective chambers relative to the pressure outside the connector.

4. Aconnector as claimed in claim 3, wherein each chamber has a wall formed at least partly of a flexible membrane arranged to permitvariation of the respec- tive chambervolume.

5. A connector as claimed in claim 4, wherein the normallysealedopeningsofthechambersareformed in respective frontwalls thereof, the flexible mem braneofeach chamber being provided in a side wall thereof, and the membrane ofthesecond chamber being laterally inwardly spaced from the side wall of thefirstchamber.

6. A connectoras claimed in claim 4, wherein the normally sealed openings ofthe chambers are formed in respective front walls thereof and the chambers share a common outer-wall, the flexible membrane of each chamber being provided in its respective front wall.

7. A connector as claimed in anypreceding claim, including a third chamber containing electrical in insulating media and located within or inwardly of the second chamber, the third chamber having an opening aligned with the otheropenings and normally sealed by the shuttle piston extending therethrough, the contact means being located within the third chamber.

8. A connector as claimed in claim 7, wherein the male part has a plurality of contact pins and thefemale parthasthesamenumberofcontact means, each contact means being separately enclosed by an individual third chamber.

9. Aconnector as claimed in any preceding claim, wherein the male connector partincludes a slidably mounted wiper seal engaging the or each cdntact pin and resiliently biased towardsthe contactend thereoN, the seal being arranged to be moved back overthe pin during mating ofthe male and female parts.