AU783297B2

AU783297B2 - Electrical cable junction box

Info

Publication number: AU783297B2
Application number: AU38227/02A
Authority: AU
Inventors: Keith Alan Jones; Kimleigh George Montague Pratley
Original assignee: Pratley Investments Pty Ltd
Current assignee: Pratley Investments Pty Ltd
Priority date: 2001-05-08
Filing date: 2002-05-08
Publication date: 2005-10-13
Anticipated expiration: 2022-05-08
Also published as: GB2375439A; GB2375439B; AU3822702A; GB0210533D0

Description

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AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: Pratley Investments (Proprietary) Ltd Actual Inventors: Kimleigh George Montague Pratley and Keith Alan Jones Address for Service: BALDWIN SHELSTON WATERS MARGARET STREET SYDNEY NSW 2000 CCN: 3710000352 Invention Title: ELECTRICAL CABLE JUNCTION BOX The following statement is a full description of this invention, including the best method of performing it known to me/us:- File: 35350AUP00 5846/2 -2- BACKGROUND OF THE INVENTION This invention relates to an electrical cable junction box.

Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

Electrical cable junction boxes, also termed electrical connection boxes, generally consist of a hollow box section and a removable lid. Typically, the box section includes one or more apertures which are designed to receive cable glands or electrical conduits. In practice, the conductors of electrical cables pass through side walls of the box section into the hollow interior of the box section where they are interconnected using electrical connection blocks or terminals.

Some of the know types of electrical cable junction boxes have a lid which is removably attachable to the box section by means of complementary screw threads on the lid and the box section. It is also known to connect the lid of an electrical cable S 15 junction box to the box section thereof by means of pins on the lid and corresponding grooves or recesses in the box section.

It is an object of the present invention at least in a preferred form to provide an electrical cable junction box with an alternative closure mechanism which allows the lid to be secured to the box section relatively easily and quickly, which provides a 20 good seal between the lid and the box section, and which allows the lid to be locked to the box section so as to bar access to the interior of the box section without a tool.

ooooo 500041632_3.DOC SUMMARY OF THE INVENTION According to the invention there is provided an electrical cable junction box comprising: a box section; a lid for the box section; a seal for sealing between the lid and the box section; at least two spaced-apart closure formations on the box section; at least two corresponding spaced-apart closure formations on the lid; sloping engagement surfaces on the box section closure formations and/or on the lid closure formations which allow the lid closure formations to engage, in a camming fashion, the box section closure formations when the lid is placed on the box section and rotated relative to the box section, thereby compressing the seal between the lid and the box section and releasably engaging the lid on the box section in a closed condition of the lid; S 15 a stop formation for limiting displacement of the lid closure formations relative to the box section closure formations so as to allow the lid to rotate into the closed condition and counter-rotate out of the closed condition without over-tightening; and locking formations on the lid and the box section, the formations being alignable with one another when the lid is in the closed condition for receiving a locking element for locking the lid to the box section in the closed condition.

9 Unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising', and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

Preferably, the stop formation is located adjacent one of the closure formations on the box section or on the lid.

500041632_3.DOC Preferably, the seal is located on the box section, and the lid includes a ridge for bearing on the seal.

Preferably, the seal includes a lip or a ridge to provide for higher localised pressure and hence better ingress protection.

The sloping engagement surface may be flat or it may be provided by the curved surface of a semi-cylindrical or cylindrical protrusion.

In one embodiment of the invention, the inner or outer periphery of the box section includes closure formations in the form of spaced protrusions with flat sloping engagement surfaces, and the outer or inner periphery, respectively, of the lid includes closure formations in the form of spaced round pegs. In this case, when the lid is placed on the box section and rotated, the round pegs on the lid engage with the sloping engagement surfaces of the protrusions on the box section to releasably engage the lid on the box section.

*"o another embodiment, the at least two closure formations on the lid comprise 15 spaced protrusions with flat sloping engagement surfaces and the at least two closure formations on the box section comprise spaced round pegs.

In a preferred arrangement, the inner or outer periphery of the box section includes at least two spaced protrusions, each of which includes a flat sloping engagement surface, and the outer or inner periphery, respectively, of the lid includes at least two 20 protrusions, each of which includes a flat sloping engagement surface complementary to the sloping engagement surface of one of the protrusions on the box section so that when the lid is placed on the box section and rotated, the flat sloping engagement surfaces of the protrusions on the lid engage with the flat sloping engagement surfaces of the protrusions on the box section to releasably engage the lid on the box section.

500041632_3.DOC Typically, the length of the spacing between the protrusions on the box section and on the lid is greater than the length of the protrusions.

Preferably, each of the box section and the lid includes eight, equally spaced-apart protrusions around the periphery thereof.

A stop may be located adjacent one or more of the closure formations on the box section or on the lid to prevent over-tightening of the lid on the box section.

Each of the box section and the lid may include a secural point such that when the lid is engaged on the box section, the secural point on the box section and the secural point on the lid co-operate with each other to permit secural of the lid to the box section in a manner that can only be unsecured using a tool.

The lid typically includes two or more spaced lugs for allowing a bar or the like to lever the lid off the box section.

The box section and the lid may each be moulded in one piece from a thermoplastics .material or a thermosetting material, preferably a thermoplastics material.

15 Alternatively, the box section and the lid may each be moulded in two or more pieces so that different types of materials may be used for the separate pieces. The pieces may then be clipped together, screwed together, or glued together for form either the box section or the lid.

The protrusions may be moulded integrally with the box section or the lid.

0 20 Alternatively, the protrusions may be inserts which fit into suitable formations in the box section of the lid.

The box section and the lid may also be manufactured by means other than moulding, for example casting, and from other materials such as a suitable metallic material.

500041632_3.DOC -6- Ideally, a gasket or sealing ring is located either on the box section or on the lid, for example in a groove in the box section or the lid, to provide the seal between the box section and the lid when the lid is in the closed condition.

The gasket or sealing ring may include a lip or ridge around its edge, on both sides, to provide for higher localised pressure and better ingress protection. This effect may be increased by including in the lid an annular ridge which is designed to bear on the gasket or the sealing ring, in use.

The lid or the box section may include a straight walled section for receiving one or more markings or labels.

The lid or the box section may also include a pair of spaced brackets adapted to accommodate a label or the like.

Alternatively, the lid or the box section may include one or more markings moulded into the lid or the box section during manufacture.

Preferably, the box section includes a base with three or more feet for accommodating t s15 unevenness in a surface to which the box section is mounted, in use.

BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention will now be described in more detail, by way of example only, with reference to the accompanying drawing in which:

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"Figure 1 shows a plan view of a box section of an electrical cable junction box according to the present invention; Figure 2 shows a cross-sectional view along the line Y-Y in Figure 1; 500041632_3 DOC -7- Figure 3 shows a side view of the box section of Figure 1; Figure 4 shows a cross-sectional view along the line X-X in Figure 1; Figure 5 shows an underplan view of the box section of Figure 1; Figure 6 shows a plan view of a lid for the box section of Figure 1; Figure 7 shows a cross-sectional view along the line Z-Z in Figure 6; Figure 8 shows a perspective view of a portion of an alternative lid for the electrical cable junction box of this embodiment of the invention; and Figure 9 shows a plan view of a box section according to another embodiment of the electrical cable junction box of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Figures 1 to 5 of the accompanying drawings illustrate a box section 10 of an electrical cable junction box according to one embodiment of the present invention.

The box section 10 includes four apertures 12 in the side wall thereof which are S•designed to receive cable glands or electrical conduits. The apertures 12 may be 15 sealed prior to use by a suitably thick web of plastics material which is designed to be drilled or broken out, if required. It will be appreciated that the box section 10 may 0 have other suitable configurations of apertures 12 for receiving cable glands or el electrical conduits.

Closure formations in the form of eight, equally spaced-apart protrusions 14 are located around the outer periphery of the box section 10. Although it is possible to utilize fewer protrusions and still achieve a satisfactory connection between the box section 10 and a lid therefor, it is preferable to have eight protrusions since this 500041632_3.DOC -8minimises the problem of warping and provides a more uniformly distributed pressure on a gasket or sealing ring between the box section and a lid.

With particular reference to Figure 3 of the drawings, each protrusion 14 is seen to include a sloping surface 16 on a lower edge thereof. The angle ca of the sloping surface, i.e. the angle between the horizontal and the sloping surface, preferably is between 30 and 450 Figure 3 also illustrates a stop 18 which is located at an end of one of the protrusions 14 to prevent over-tightening of a lid on the box section The box section carries a secural point in the form of a lug 20 which defines an opening 22. The method of locking a lid to the box section 10 with the secural point will be described in more details below.

With specific reference to Figure 2 of the accompanying drawings, a gasket or sealing ring 24 is seen located in a groove 26 in the box section 10. When a lid is placed onto the box section, the sealing ring or gasket 24 is compressed between the lid and the box section to ensure a seal between the lid and the box section. The sealing ring 15 has a specific shape which is of particular application in the electrical able junction box of the embodiment of the invention. In this regard, a portion 24A of the sealing

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b° 0-ring is illustrated in an enlargement in Figure 2 where it is seen to include a lip or ridge 25 around its edge, on both sides. This provides for higher localised pressure and better ingress protection. The gasket or sealing ring 24 is symmetrical so that it does 4*e not matter which way it is placed onto the box section 10 in use.

Referring now to Figures 4 and 5, the box section 10 includes abase 28 which carries four feet 30. From Figure 4, it can be seen that the feet 30 are proud of the base 28 so as to accommodate unevenness in a surface to which the box section 10 is to be mounted. Each foot 30 defines an opening 32 for attaching the box section to a surface.

500041632_3.DOC -9- In this embodiment of the invention, the box section 10 is moulded in one piece from a thermoplastics material. However, the box section 10 could be moulded in two or more pieces, in which case two or more different types of materials could be used for the separate pieces. The pieces may then be clipped together, screwed together or glued together to form the box section Figures 6 and 7 show a lid 40 for the box section illustrated in Figures 1 to 5 of the drawings. In Figure 7. the lid 40 is seen to include eight protrusions 42 on the inner periphery thereof. These protrusions are complementary to the protrusions 14 on the box section 10 and include corresponding sloping surfaces 44 on upper edges thereof.

In use, the lid 40 is located on the box section 10 with the protrusions 42 located in the spaces between the protrusions 14. The lid 40 is then rotated relative to the box section 10 to bring the sloping surfaces 44 on the protrusions 42 into engagement with the sloping surfaces 16 on the protrusions 14, thereby to releasably engage the lid 40 on the box section 10 in a closed condition. As indicated above, the stop 18 prevents over-tightening of the lid on the box section The lid 40 also includes two lugs 46 which allow the lid to be levered off the box section 10 with a bar or the like. In this regard, the bar is placed on the lid between the two lugs 46 and then rotated relative to the box section 10 to turn the lid relative to the box section.

An alternative shape for the edge 48 of the lid 40 is illustrated in the circled in Figure 7. As can be seen, the edge 48A is tapered to facilitate compression of the gasket or sealing ring 24 between the lid 40 and the box section The lid 40 also includes a secural point in the form of a lug 50 defining an opening 52. When the lid 40 is in the closed condition on the box section the lugs 20 and 50, and thus the openings 22 and 52, are in register. The lid may then be locked to the box section by means of a suitable securing device can only be removed with a tool, for example a bolt secured in the openings 22 and 52 with a nut, a cable tie or a padlock.

Figure 8 shows an alternative lid section 60 for the box section 10 illustrated in Figures 1 to 5. In this embodiment, the lid 60 is similar in many respects to the ildid 40 of Figures 6 and 7, but unlike the lid 40 includes two brackets 62 which permit a label 64 to be slotted therebetween. In this way, the lid 60 may be marked.

Alternatively, the lid 60 may include a straight walled section on which can be located one or more markings or labels, or the lid 60 may be moulded to include one or more markings.

As with the box section 10, the lid 40 or the lid 60 may be moulded in one piece in a thermoplastics material, or they may be moulded in two or more pieces so that different types of materials can be used for the separate pieces.

The box section 10 and/or the lid 40 or the lid 60 may also be formed from a 2Q clear plastics material, if desired, so as to allow visual inspection of the interior of the box section In Figure 9, there is shown a box section 80 of an electrical cable junction box according to another embodiment of the invention. The box section 80 differs from box section 10 in that the protrusions 82 are located around the inner periphery of the box section 80 as opposed.to the outer periphery of the box section 10. In all other respects, the protrusions 82 are identical to the protrusions 14 on the box section 10, i.e. the protrusions 82 include sloping surfaces on lower edge thereof.

-11 A lid for the box section 80 will include eight complementary protrusions on the outer periphery thereof for engaging the protrusions 82 on the box section when the lid is rotated into a closed condition on the box section 80. In all other respects, the box section 80 is the same as the box section 10 of Figures 1 to A major advantage of the electrical cable junction box according to the present invention is that the closure formations on the lid and on the box section allow the lid to be secured to the box section relatively easily and quickly.

Furthermore, the sealing ring or gasket 24 provides a good seal between the lid and the box section, and the lugs 20 and 50 allow the lid to be locked to the box section, thereby barring access to the hollow interior of the box section without a tool.

Claims

1. An electrical cable junction box comprising: a box section; a lid for the box section a seal for sealing between the lid and the box section; at least two spaced-apart closure formations on the box section at least two corresponding spaced apart closure formations on the lid; sloping engagement surfaces on the box section closure formations and/or on the lid closure formations which allow the lid closure formations to engage, in a camming fashion, the box section closure formations when the lid is placed on the box section and rotated relative to the box section, thereby compressing the seal between the lid and the box section and releasably engaging the lid on the box section in a closed condition of the lid; a stop formation for limiting displacement of the lid closure formations relative to the box section closure formations so as to allow the lid to rotate into the closed condition and counter-rotate out of the closed condition o without over-tightening; and 20 locking formations on the lid and the box section, the locking formations being alignable with one another when the lid is in the closed condition for receiving a locking element for locking the lid to the box section in S. the closed condition.

2. An electrical cable junction box according to claim 1, wherein the stop 25 formation is located adjacent one of the closure formations on the box section Oi 9 or on the lid. 9

3. An electrical cable junction box according to claim 1 or claim 2, wherein the seal is located on the box section, and the lid includes a ridge for bearing on 9 the seal.

4. An electrical cable junction box according to any one of the preceding claims, wherein the seal includes a lip or a ridge to provide for higher localised pressure and hence better ingress protection. 500041632_3.DOC -13- An electrical cable junction box according to any one of the preceding claims, wherein the closure formations on the box section comprise protrusions on the outer periphery of the box section, and the closure formations on the lid comprise protrusions on the inner periphery of the lid.

6. An electrical cable junction box according to any one of the claims 1 to 4, wherein the closure formations on the box section comprise protrusions on the inner periphery of the box section, and the closure formations on the lid comprise protrusions on the outer periphery of the lid.

7. An electrical cable junction box according to any one of the preceding claims, including sloping engagement surfaces on the closure formations on the box section and complementary sloping engagement surfaces of the closure formations on the lid.

8. An electrical cable junction box according to any one of the preceding claimsl to 4, including curved sloping engagement surfaces.

9. An electrical cable junction box according to claim 8, wherein the closure formations on the box section include flat sloping engagement surfaces and S:I the closure formations on the lid comprise cylindrical or semi-cylindrical protrusions. S

000010. An electrical cable junction box according to claim 8, wherein the closure formations on the lid include flat sloping engagement surfaces and the closure formations on the box section comprise cylindrical or semi-cylindrical *0 00 0• protrusions. 0 ee.. 11. An electrical cable junction box according to any one of the preceding claims, 0 °o wherein the length of the spacing between the spaced-apart closure formations o 25 on the box section and on the lid is greater than the length of each closure °0 formation.

12. An electrical cable junction box according to any one of the preceding claims, wherein the box section includes eight closure formations and the lid includes eight corresponding closure formations. 500041632_3.DOC -14-

13. An electrical cable junction box according to any one of the preceding claims, wherein the closure formations on the box section are equally spaced around the box section and the closure formations on the lid are equally spaced around the lid.

14. An electrical cable junction box according to any one of the preceding claims, wherein the locking means comprises a secural point on the box section and a corresponding secural point on the lid, the secural points being arranged to co- operate with one another when the lid is in the closed condition so as to permit secural of the lid to the box section in a manner that can only be unsecured using a tool. An electrical cable junction box according to claim 14, wherein the secural point on the box section and the secural point on the lid comprise a pair of lugs with openings which are arranged to be aligned with one another when the lid is in the closed condition, thereby allowing a fastener to extend through the openings and lock the lid to the box section.

16. An electrical cable junction box according to any one of the preceding claims, 4 wherein the lid carries two or more spaced lugs for facilitating the removal of l the lid from the box section.

17. An electrical cable junction box according to any one of the preceding claims, wherein the lid or the box section includes a straight walled section for receiving markings or labels. o.

18. An electrical cable junction box according to any one of the preceding claims, wherein the lid or the box section includes a pair of spaced brackets adapted to •accommodate a label. .9. 0O ,O•D 25 19. An electrical cable junction box according to any one of the preceding claims, wherein the lid or box section includes one or more markings moulded into the lid or the box section during manufacture. An electrical cable junction box according to any one of the preceding claims, wherein the box section includes a base with three or more feet. 500041632 3.DOC

21. An electrical cable junction box substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples. DATED this 1 1 th day of August 2005 Shelston IP Attorneys for Pratley Investments (Proprietary) Ltd *o o *o •ooo 500041632_3.DOC