AU746779B2

AU746779B2 - Electric connection sealing arrangement

Info

Publication number: AU746779B2
Application number: AU48809/99A
Authority: AU
Inventors: Ian Guthrie
Original assignee: Spa Electrics Pty Ltd
Current assignee: Spa Electrics Pty Ltd
Priority date: 1998-09-23
Filing date: 1999-09-20
Publication date: 2002-05-02
Anticipated expiration: 2019-09-20
Also published as: AU4880999A

Description

Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT w..

00t.

Invention Title: Applicant: ELECTRICAL CONNECTION SEALING ARRANGEMENT SPA ELECTRICS PTY LTD The following statement is a fuill description of this invention, including the best method of performing it known to me: C.IqNWORMHAROMNDREMPCTCOC4P CTFORMS.DC ELECTRICAL CONNECTION SEALING ARRANGEMENT The present invention relates to a sealing arrangement for an electrical connection. The invention has principle application in a connection for an underwater light, such as for use in swimming pools or spas and it will therefore be convenient to describe the invention in relation to that application. However, it should be appreciated that the invention may have wider application, such as in aquariums or in other liquid containing vessels, or in other general applications in which an electrical connection is exposed to moisture or liquid and in which it is necessary, or at least desirable, to prevent or minimise progression of that moisture or liquid along the connection.

A variety of lights are known and used in swimming pools and spas.

Examples of such lights are shown in Applicant's earlier Australian Patent 629741, and in Australian Patent 512079 in the name of Dega Pty Ltd. These examples illustrate that underwater lights need to be securely sealed against ingress of water, so that electrical wires and fittings are protected from contact therewith.

Water contact with the electric's of an underwater light can have minor but inconvenient consequences, by disabling the light through short circuit or corrosion. This may result in a blown fuse or a tripped circuit switch, or more inconveniently, the lamp or globe, may be blown requiring replacement.

Alternatively, such water contact may have far more serious consequences, by electrocution of swimmers or bathers although generally, lighting in such areas operates at extra low voltage, so that there is normally little risk of electrocution.

In view of the inconvenience associated with repair or replacement of .o 25 underwater lights, effective sealing of lights against ingress of water is important.

It is an object of the present invention to provide an improved or alternative form of seal for an electrical connection for preventing or minimising progression of moisture or liquid through or along the connection.

According to the present invention there is provided an electrical connector for connecting an electrical cable to an electrical device, including a solid, electrically conductive connector member having an elongate portion that 0 0 *000 0* 0* 0* 0* includes a plurality of rings extending outwardly from said elongate portion and spaced apart lengthwise therealong, said rings defining a plurality of raised and recessed sections along said elongate portion, said electrical connector further including a body within which said elongate portion is positioned, said body including portions that extend into engagement with said electrical connector with or between adjacent said rings to present a barrier to progression of liquid along said elongate portion.

The present invention further provides an electric light having a sealed chamber for accommodating an electric light source, said chamber being partly defined by a lens through which light can be transmitted, said electric light further including an electrical connector for connecting said electric light source to an electricity source, said electrical connector including a solid, electrically conductive connector member having an elongate portion that includes a plurality of rings extending outwardly from said elongate portion and coaxially spaced apart lengthwise therealong, said rings defining a plurality of raised and recessed sections along said elongate portion, said electrical connector further including a body within which said elongate portion is positioned, said body including portions that extend into engagement with said electrical connector with or between adjacent said rings to present a barrier to progression of liquid along said elongate portion.

The present invention is distinguished from previous arrangements in which an electrical cable extends through the rear of the underwater light and into the sealed compartment in which the globe is positioned. In those arrangements, the sealed compartment can become flooded in the event that the plastic casing of the cable that encloses the cable wires is pierced or broken. That permits moisture or liquid to enter the cable and to track through the cable into the sealed compartment. However, by use of the present invention, the electric cable can be attached to the electrical connector, preferably at one end of the elongate portion of the connector member, and any water that has entered the cable through a break in the plastic cable casing, progresses only to the connection between the cable and the electrical connector. It cannot progress further, because the connector member of the 6

SEC

electrical connector is solid so that any liquid or moisture cannot track through it in the manner it tracks through the cable, while that moisture or liquid is also prevented from travel along the outside of the connector member by the barrier formed by cooperation between the rings and the body. For the purposes of this specification, a reference to liquid hereinafter includes within its scope, moisture.

The body according to the invention can take any suitable form and may, for example, be a wall of a vessel, or an insert in the wall of a vessel.

Alternatively, the invention can be applied to electrical devices that are not water immersed, but which are still exposed to liquid infiltration, such as devices located outdoors, or below the ground etc. Alternatively, the body may simply be a substrate of any suitable kind that can be fixed in position relative to the device for which the electrical connection is provided, such as to the wall of the vessel, either on the inside or the outside as appropriate.

A light which employs the electrical connection of the present invention I preferably includes a sealed chamber for accommodating an electric light source, which chamber includes a lens through which electric light can be 4 transmitted. For an underwater light, the body, into which the elongate portion of the connector is positioned, preferably is a backing member forming a rear wall of the sealed chamber, or backing the chamber in sealed connection therewith. The elongate portion may extend through any part of the backing member and in use, it can, for example, be disposed horizontally or vertically, or at an angle through the backing member. Moreover, the elongate portion may extend through a side, or rear, or other section of the backing member, as S 25 is appropriate or convenient. Such a light preferably includes a pair of spaced :apart electrical connectors extending from the chamber through the backing 4 member into connection with an electric cable that extends from the light through a seal. Each of the electrical connectors has an elongate portion that includes a plurality of rings extending about the connector and defining a plurality of raised' and recessed sections along that portion. At least in the region of each elongate portion, each connector is positioned within the backing CA member and the backing member is so formed, such that portions of the )E.1 o backing member extend into engagement with each connector with or between adjacent rings, at least at times when the light has been switched off and is cooling down, so that the engagement presents a barrier against the progression of water along the elongate portion of each connector.

A light according to the present invention is advantageous, because the barrier formed against progression of water along the electrical connectors eliminates, or at least minimises ingress of water into the sealed chamber.

Such ingress occurs principally on cool-down of a light when the light is switched off from an on-condition. This can occur because the various components of the light which heat up when the light is switched on, cool down when the light is switched off and that causes a vacuum to be generated that tends to suck water along the electrical connection of the light (whatever form of connection the light has). The cooling occurs at different rates for different materials, and the vacuum is caused by different shrinkage rates of the different materials. Water for example can leak past the electric cable seal (normally a gland seal) and along the outside of the cable into the sealed chamber under the induced vacuum. However, in a light according to the invention, leakage of water into the chamber via the electric cable is eliminated or at least minimised, by the existence of the electrical connectors as defined which are arranged 20 within the backing member in the manner described.

*o

S

il S S.e The above identified problem caused by lighting heating does not present the sole reason for adopting the electrical connection of the present invention. The connection is applicable to a wide variety of electrical components that are subject to infiltration of liquid. For example, applicant considers the invention to have application to salt water chlorinators, in which the electrical connection extends through the wall of the salt water containing vessel to an electrode inside the vessel and to a power supply outside thereof.

In some arrangements of this kind, the connection on the outside of the vessel is disposed in a body of epoxy that seals the connection. However, the epoxy can, over time, crack and that facilitates ingress of liquid along the connection.

Such ingress will be prevented, or at least minimised by adopting the sealing arrangement of the present invention.

A particular advantage of the invention, is that the electrical connector no longer needs to extend through the gasket or seal of an underwater light as in previous arrangements, but can extend more conveniently through the lens, or backing member or other suitable component part thereof.

The backing member of an underwater light described above can take any suitable form and may be connected to the sealed chamber by any suitable sealed arrangement. For example, the backing member may be fully or partly formed by a plastic moulding that is formed about the rings of the elongate portions so that the connectors are embedded within the backing member.

Alternatively, the backing member may be of a mouldable foam material, or may comprise an outer casing that is filled with a setting material such as a suitable resin, or equally a plastic or foam. In this latter form, the backing member may not be completely filled with the resin, plastic or foam, but may be filled only in those regions to embed the elongate portions. Equally, the backing member may consist only of portions suitable to embed the connectors.

Likewise, a body according to the invention can have any one of the forms described for the backing member.

In the above preferred form, embedding the connector within the backing member provides significant resistance to progression of water along the length of the connector because the existence of the rings interrupts that progression C:\WINWORD SHARONMNDREW\PCTCOMX539281C.DOC 6 and engagement of the rings with portions of the backing member presents a barrier to the progression. Thus, the power source is protected from seepage of water along the length of the connector that may otherwise occur.

The rings of the connectors may be secured to the peripheral surface thereof by any suitable means, but preferably, they are integrally formed of the same material as the connectors. The connectors can be of any suitable conducting material, but preferably are substantially inert to degradation by water, so that the connectors are preferably copper or brass. The connectors may be cast and/or machined as appropriate. Alternatively, the rings may be fixed to the connectors, such as by adhesive or as a friction fit.

~The attached drawings show example embodiments of the invention included in an assembly of the foregoing kind. The particularity of the drawings and the associated description does not supersede the generality of the preceding broad description of the invention.

Figure 1 is a cross-sectional view of a light that includes an electrical connector according to the invention.

Figure 2 is a cross-sectional view of an electrical connector according to S-another aspect of the invention.

A simplified schematic drawing of the invention is shown in Figure 1. In that figure, a light 10 according to the invention is shown. The light 10 includes a lens 11 connected to a frame or rim 12 to form a sealed chamber 13. The lens 11 may be connected to the frame 12 in any suitable sealed manner, such as by the arrangement shown in Australian Patent 629741 which is incorporated herein by cross-reference. The connection between the lens 11 and the frame 12 should be watertight so that a watertight chamber for housing an electric light source 15 is provided. Thus, a gasket may be provided between the lens 11 and the frame 12. The light source 15 is not shown in any detail, but can comprise any suitable arrangement of which there are several that are well known.

Connected to the frame or rim 12, is a backing member 16 and connected to the backing member 16 is an electrical circuit box 17. The backing member 16 may be connected to the circuit box 17 in any suitable C:\WINWORD\SKAROIMANDREVAPCTCOMP,539281C.DOC manner, such as by releasable screw threaded fasteners, or by non-releasable adhesives. Other methods of connection may also be appropriate. Equally, the circuit may form part of the backing member so that it is not an add-on component. The backing member 16 as shown, is connected to the rear of the frame 12, but it could equally be connected on the peripheral sides of the rim which connect to the lens 11. In such a case, the backing member would be a modified form of that shown in Figure 1. Additionally, the frame 12 and the backing member 16 may be separate items as shown, or they may be formed as a single integral item. The circuit box 17 is an enclosure over certain electrical connections that will be described hereinafter.

Extending between the light source 15 and the electrical circuit box 17, through the backing member 16, is a pair of electrical connectors 18. The connectors are identical and include means (not shown) for connection to the light source 15 and includes threaded ends 19 to received a terminal bolt The threaded ends 19 and the terminal bolt 20 are enclosed within the circuit box 17. Flex cabling 21 extends from the terminal bolts 20, through the wall of the circuit box 17 through a cable gland 22 to an electric power source. The circuit box 17 may be filled with a suitable filler, such as an epoxy resin or foam or the like, or it may be left open.

The light 10 is fixable to the wall of a pool or spa in any normal manner and a recess in the wall may be provided for that purpose. Of course, the :.i configuration of the light 10 may not be suitable for all applications and therefore the light 10 is to be understood as representative of only one style of light that embodies the invention.

Each of the electrical connectors 18 includes a plurality of rings 23 which are fixed to, or formed integrally with each connector. The rings 23 are formed along an elongate portion 24 of each connector 18 and are spread apart to define a plurality of raised and recessed sections as shown. The elongate portions 24 of both the electrical connectors 18 are embedded within the backing member 16 such that the material of the backing member engages against the rings 23 and in the arrangement shown, the material of the backing member 16 extends into the recesses 25 between adjacent rings 23. For this, C:\WINWORD\SHARONMNDREW\PCTCOMP\539281C.DOC 8 the backing member is formed of a mouldable plastic or foam which is formed about the connectors 18. That is, the backing member 16 is formed about the connectors 18 in a mould or the like, so that the material of the backing member engages the rings 23 and fills the recesses 25. The connectors 18 can be placed in the mould used to form the backing member to create this arrangement.

The backing member 16 as described above constitutes a relatively solid form, but that is not necessarily the case for all such backing members according to the invention. The backing member may for example comprise a casing that accommodates material suitable to embed, in the manner required, the elongate portions 24 of the electrical connectors 18, and that material may not completely fill the casing, but may only be located in the immediate vicinity of the elongate portions.

The light 10 operates by conduction of electrical current through the flex cabling 21 to the connectors 18 and to the light source 15. That electrical conduction generates heat and when the light is switched off, the various components of the light cool at different rates. The different rates of cooling is such as to generate a vacuum in the sealed chamber 13 and in known S arrangements, in which the cable flex extends through a sealed opening into the sealed chamber, water can penetrate through the sealed opening and seep into the sealed chamber to the electrical light connections, and can result in the aforementioned problems. In the light shown, water surrounding the light would tend to be sucked into the electrical circuit box 17, past the cable gland 22 and along the electrical connector 18, so as to enter the chamber 13 by the action of a vacuum created in the chamber 13. However, in the light arrangement shown, the plurality of rings 23 that are engaged by the backing member 16, resists the progression of water in either direction along the elongate portions 24. Thus, water is prevented or at least substantially prevented from entering the chamber 13 under the influence of the vacuum generated under cooling. Filling the circuit box 17 with a filler further resists ingress of water into the sealed chamber.

C:\WINORDSHROANDREWAPCTCOMP\539281C.DOC 9 The light includes a plurality of rings 23, so that if the vacuum is such as to force water past a ring, a second ring is encountered that presents a further barrier. It is envisaged that a number of rings, such as five, would prevent ingress of water into the sealed chamber from along the connectors under most conditions. However, additional or less rings can be used if circumstances permit.

The arrangement of the connectors 18 in the backing member 16 also protects the chamber 13 against leakage of water along the electrical connections that may occur independently of leakage under vacuum.

An alternative form of connector 118 is shown in cross-section in Figure 2. The same reference numerals, plus 100, are used to denote like parts from

IIII

Figure 1. The connector 118 is cylindrical with hollow, threaded sections extending inwardly from each axial end 119 of the connector, for receipt of threaded connectors (not shown) for connecting the connector 118 to a light source and a power source (not shown) respectively. The outer surface 131 of the connector 118 includes four raised rings 123 which define three recesses 125. The connector 118 operates in the same manner as the connector 18 of Figure 1.

A connector 118 of the kind shown in Figure 2, has broader outer rings 20 surfaces 131 compared to the rings 23 of Figure 1. Advantageously, those broad surfaces may be roughened by known techniques so that the material :.i into which the connector is embedded, can grip the outer ring surfaces and securely hold the connector 118 in place.

The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the spirit and scope of the above description.

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Claims

1. An electrical connector for connecting an electrical cable to an electrical device, including a solid, electrically conductive connector member having an elongate portion that includes a plurality of rings extending outwardly from said elongate portion and coaxially spaced apart lengthwise therealong, said rings defining a plurality of raised and recessed sections along said elongate portion, said electrical connector further including a body within which said elongate portion is positioned, said body including portions that extend into engagement with said electrical connector with or between adjacent said rings to present a barrier to progression of liquid along said elongate portion.

2. The electrical connector according to claim 1, wherein said body is the wall of a vessel for containing liquid.

3. An electrical connector according to claim 1, wherein said body is an insert for insertion in the wall of a vessel for containing liquid.

4. An electric light having a sealed chamber for accommodating an electric 20 light source, said chamber being partly defined by a lens through which light can be transmitted, said electric light further including an electrical connector for connecting said electric light source to an electricity source, said electrical 00 connector including a solid, electrically conductive connector member having an elongate portion that includes a plurality of rings extending outwardly from said 25 elongate portion and coaxially spaced apart lengthwise therealong, said rings defining a plurality of raised and recessed sections along said elongate portion, said electrical connector further including a body within which said elongate portion is positioned, said body including portions that extend into engagement with said electrical connector with or between adjacent said rings to present a barrier to progression of liquid along said elongate portion. 11 An electric light according to claim 4, said body being a backing member forming a rear wall of said sealed chamber.

6. An electric light according to claim 4, said body being a backing member sealingly connected to said sealed chamber.

7. An electric light according to claim 5 or 6, wherein said backing member is a plastic moulding which is formed about said elongate portion such that said rings thereof are embedded within said backing member.

8. An electric light according to claim 5 or 6, wherein said backing member is a mouldable foam material which is moulded about said elongate portion such that said rings thereof are embedded within said backing member.

9. An electric light according to claim 5 or 6, wherein said backing member includes a casing enclosing a settable material which is set within the casing so that said rings of said elongate portion are embedded within said settable material. :o 0" 20 10. An electric light according to any one of claims 4 to 9, said electricity source being connected to said connector member by an electric cable.

11. An electric light according to any one of claims 4 to 10 including a pair of said connector members extending through said body between said sealed chamber and said electricity source. a.

12. An electric light according to any one of claims 4 to 11, said rings being formed integrally with said connector member.

13. An electric light according to any one of claims 4 to 11, said rings being formed separately to said connector members and being fixed thereto.

14. An electric light according to any one of claims 4 to 13, further including an electric circuit box attached to said body and including connecting means for connecting said connector member to said electric power source.

15. An electrical light according to claim 15, including flexible cabling in said electrical circuit box extending from said connector member and out of said electrical circuit box through a gland seal into said electric power source.

16. An electrical connector substantially as herein described with reference to Figure 1. 4. o 6

17. An electric light substantially as herein described with reference to Figure 1. DATED: 20 September 1999 PHILLIPS ORMONDE FITZPATRICK Attorneys for: SPA ELECTRICS PTY LTD C:\WINWORD\SHARONIANDREW\ PCTCOMP\5281C.O