AU2009101205A4

AU2009101205A4 - Extension cord coupling

Info

Publication number: AU2009101205A4
Application number: AU2009101205A
Authority: AU
Inventors: David Hutchings
Original assignee: Tubing & Electrical Ind Pty Lt
Current assignee: Tubing & Electrical Industries Pty Ltd
Priority date: 2009-11-25
Filing date: 2009-11-25
Publication date: 2010-01-28
Anticipated expiration: 2017-11-25

Description

1 Extension cord coupling FIELD OF THE INVENTION The present invention relates to an extension cord coupling, in particular an extension cord coupling that provides environmental protection for mated extension 5 cord ends as well as keeping the ends mated. BACKGROUND TO THE INVENTION Extension cords for mains electricity are frequently used in outdoors situations where they are subject to both the elements and mechanical pressures. As the mating ends are only held together by a friction fit they are subject to disengagement when 10 either of the cords is pulled upon resulting in an inconvenient loss of power. The connecting ends are often susceptible to ingress of dirt or moisture. This can lead to either corrosion or shorting of the contacts. Numerous couplings for extension cords have been developed over the years. These devices have either ignored the problem of moisture ingress, have been 15 mechanically cumbersome and hence expensive to manufacture or have not been mechanically robust. The object of this invention is to provide an extension cord coupling that alleviates the above problems, or at least provides the public with a useful alternative. SUMMARY OF THE INVENTION 20 Therefore, in one form of the invention there is proposed a coupling for two mating electrical plugs, each plug having a first end to which an associated electrical cord is connected and a second mating end of larger cross section to that of said first end, said coupling including: a first hollow body including an internal surface conformed to accommodate a first of 25 said electrical plugs, said first hollow body including an external thread adjacent said mating end and an external abutment surface having associated therewith a resilient sealing ring; a second hollow body including an internal surface conformed to accommodate the second electrical plug, said second hollow body including an internal thread adjacent 30 said mating end adapted for engagement with said first body external thread, said internal thread including at an end thereof an abutment surface being co-operable with 2 said first body abutment surface; and whereby tightening of said second hollow body over said external thread causes compression of said sealing ring and sealable engagement between said first and second hollow bodies. 5 Preferably said first hollow body internal surface includes an internal abutment surface adjacent said electrical cord end which is co-operable with an external abutment surface of said first electrical plug, said internal abutment surface having associated therewith a resilient sealing ring whereby tightening of said second hollow body over said external thread causes compression of said resilient sealing ring and 10 sealable engagement between said first hollow body and said first plug. In preference said second hollow body internal surface includes an internal abutment surface adjacent said electrical cord end which is co-operable with an external abutment surface of said second electrical plug, said internal abutment surface having associated therewith a resilient sealing ring whereby tightening of said 15 second hollow body over said external thread causes compression of said resilient sealing ring and sealable engagement between said second hollow body and said second plug. Alternatively the invention can be considered as a protective housing for two connecting electrical plugs, said protective housing including: 20 a first hollow body which is conformed to fit over a first of the two connecting electrical plugs, said first hollow body including an external thread at an end thereof; a second hollow body which is conformed to fit over the second of the two connecting electrical plugs, said second hollow body including an internal thread adapted to threadably engage said external thread; 25 a first O-ring for providing a seal between said first and second hollow bodies, said first O-ring being compressed when said first and second hollow bodies are fully engaged; a second O-ring for providing a seal between said first hollow body and said first electrical plug, said second O-ring being compressed when said first and second hollow bodies are fully engaged; and 30 a third O-ring for providing a seal between said second hollow body and said second electrical plug, said third O-ring being compressed when said first and second hollow bodies are fully engaged. It should be noted that any one of the aspects mentioned above may include any of the features of any of the other aspects mentioned above and may include any of 35 the features of any of the embodiments described below as appropriate.

3 BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an exemplary implementation of the invention and, together with the description, serve to explain the advantages and principles of the invention. In 5 the drawings: Figure 1 is a side view of the two halves of an extension cord coupling; Figure 2 is a side view of two mating extension cord ends; Figure 3 is a side view of the extension cord coupling of figure 1 fitted to the extension cord ends of Figure 2 in a disengaged position; 10 Figure 4 is a cross sectional view of the extension cord coupling of Figure 3; Figure 5 is a side view of the two halves of an extension cord coupling fitted to extension cords in an engaged position; and Figure 6 is a cross sectional view of the extension cord coupling of Figure 5. DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 15 The following detailed description of the invention refers to the accompanying drawings. Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the same reference numbers will be used throughout the drawings and the following 20 description to refer to the same and like parts. Dimensions of certain parts shown in the drawings may have been modified and/or exaggerated for the purposes of clarity or illustration. The invention relates to an extension cord coupling consisting of two mating halves 10 and 20 as shown in Figure 1 shaped to fit over two extension cord ends 30 25 and 40 as shown in Figure 2. Figure 3 shows the coupling halves 10 and 20 fitted to the extension cord ends 30 and 40. Figure 4 shows Figure 3 in cross section. The socket coupling half 10 of the extension cord coupling fits over the socket end 30 of an extension cord. The socket coupling half comprises a shell body 11, a front 0-ring 15 and a rear 0-ring 17. The shell body features a large front opening 12, 30 a small rear opening 13, an external thread 14, an internal lip 18 on which the rear 0 ring 17 is seated and an external lip 16 on which the front 0-ring 15 is seated. The shell body 11 is sized to accommodate the body 31 of the extension cord socket 30.

4 The front opening 12 is sized to accommodate the face 32 of the socket. The rear opening 13 is sized to accommodate the tail 33 of the socket but sized smaller than the rear lip 34 of the tail. The socket coupling half is thus free to rotate as well as move back and forth in relation to the socket, but is retained by the rear lip of the socket tail. 5 The plug coupling half 20 of the extension cord coupling fits over the plug end 40 of an extension cord. The plug coupling half comprises a shell body 21 and a rear 0 ring 27. The shell body features a large front opening 22, a small rear opening 23, an internal thread 24 and an internal lip 28 on which the rear O-ring 27 is seated. The shell body 21 is sized to accommodate the body 41 of the extension cord plug 40. The 10 front opening 22 is sized such that the internal thread 24 will mate with the corresponding external thread 14 of the socket coupling half 10. The rear opening 23 is sized to accommodate the tail 43 of the plug but sized smaller than the rear lip 44 of the tail. The plug coupling half is thus free to rotate as well as move back and forth in relation to the plug, but is retained by the rear lip of the plug tail. The plug coupling half 15 also features an internal lip 26 into which the front O-ring 15 of the socket coupling half 10 can be accommodated. Figure 5 shows how the two halves of an extension cord coupling can be joined together to protect a mated socket end and plug end of an extension cord. Figure 6 shows the same in cross section. To join the two halves together the external thread 20 14 of the socket coupling half 10 is engaged with the internal thread 24 of the plug coupling half 20 and then the two halves are rotated with respect to each other. As the two halves are rotated they are drawn together until a point of full engagement is reached when the lip 16 of the socket coupling half comes into contact with the front face 29 of the plug coupling half. 25 As the point of full engagement is reached the three O-rings 15, 17 and 27 are simultaneously compressed. The front O-ring 15 of the socket coupling half 10 is compressed between the external lip 16 of the socket coupling half and the internal lip 26 of the plug coupling half 20. The rear O-ring 17 of the socket coupling half 10 is compressed between the internal lip 18 of the socket coupling half and the shoulder 35 30 of the socket end 30. The rear O-ring 27 of the plug coupling half 20 is compressed between the internal lip 28 of the socket coupling half and the shoulder 45 of the plug end 40. At the point of full engagement, with the three O-rings compressed, the extension cord coupling forms an enclosure that provides environmental protection for the mated 5 extension cord ends. The enclosure provides protection against the ingress of dust and water to an IP66 standard. When fully or even partially engaged the extension cord coupling prevents the mated extension cord ends from becoming unintentionally separated. 5 In any claims that follow and in the summary of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprising" is used in the sense of "including", i.e. the features specified may be associated with further features in various embodiments of the invention.

Claims

1. A coupling for two mating electrical plugs, each plug having a first end to which an associated electrical cord is connected and a second mating end of larger cross section to that of said first end, said coupling including: 5 a first hollow body including an internal surface conformed to accommodate a first of said electrical plugs, said first hollow body including an external thread adjacent said mating end and an external abutment surface having associated therewith a resilient sealing ring; a second hollow body including an internal surface conformed to 10 accommodate the second electrical plug, said second hollow body including an internal thread adjacent said mating end adapted for engagement with said first body external thread, said internal thread including at an end thereof an abutment surface being co-operable with said first body abutment surface; and 15 whereby tightening of said second hollow body over said external thread causes compression of said sealing ring and sealable engagement between said first and second hollow bodies.

2. A coupling according to claim 1 wherein said first hollow body internal surface includes an internal abutment surface adjacent said electrical cord 20 end which is co-operable with an external abutment surface of said first electrical plug, said internal abutment surface having associated therewith a resilient sealing ring whereby tightening of said second hollow body over said external thread causes compression of said resilient sealing ring and sealable engagement between said first hollow body and said first plug. 25

3. A coupling according to claim 2 wherein said second hollow body internal surface includes an internal abutment surface adjacent said electrical cord end which is co-operable with an external abutment surface of said second electrical plug, said internal abutment surface having associated therewith a resilient sealing ring whereby tightening of said second hollow body over 30 said external thread causes compression of said resilient sealing ring and sealable engagement between said second hollow body and said second plug. 7

4. A protective housing for two connecting electrical plugs, said protective housing including: a first hollow body which is conformed to fit over a first of the two connecting electrical plugs, said first hollow body including an external 5 thread at an end thereof; a second hollow body which is conformed to fit over the second of the two connecting electrical plugs, said second hollow body including an internal thread adapted to threadably engage said external thread; a first O-ring for providing a seal between said first and second hollow 10 bodies, said first O-ring being compressed when said first and second hollow bodies are fully engaged; a second O-ring for providing a seal between said first hollow body and said first electrical plug, said second O-ring being compressed when said first and second hollow bodies are fully engaged; and 15 a third O-ring for providing a seal between said second hollow body and said second electrical plug, said third O-ring being compressed when said first and second hollow bodies are fully engaged.

5. A protective housing for two connecting electrical plugs substantially as hereinbefore described with reference to the drawings. 20 Dated: 2 4 th November 2009 Key Tubing and Electrical Industries By their Patent Attorneys Lesicar Perrin 25