AU664378B2

AU664378B2 - Electrical fitting

Info

Publication number: AU664378B2
Application number: AU22001/92A
Authority: AU
Inventors: Peter Simon
Original assignee: HPM Industries Pty Ltd
Current assignee: HPM Industries Pty Ltd
Priority date: 1991-09-10
Filing date: 1992-08-28
Publication date: 1995-11-16
Anticipated expiration: 2012-08-28
Also published as: AU2200192A

Description

-1- P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT 6F 47 Invention Title: ELECTRICAL FITTING a s s a a aa a a a a a a The following statement is a full description of this invention, including the best method of performing it known to me/us: GH&CO REF: P04210-PO:PJW c e a a a cc a a a a s~ 2 The present invention relates to electrical fittings and more particularly, to electrical fittings of the kind in which electrical components electrical conductors) are housed within interconnected mouldings.

A power board which provides a plurality of power outlets from a single power inlet is an example of such an electrical fitting.

Conventional electrical fi'ttings typically comprise electrical components located between moulding components, with screws or similar fasteners being used to secure the moulding components together. Whilst this approach has been found generally acceptable, it does result in relatively high product assembly costs and the fittings may readily be disassembled by unskilled persons. The applicant has recognised that a more convenient and permanent arrangement for securing the mouldings together would be of benefit.

Accordingly, the present invention provides an electrical fitting comprising electrical components housed within interconnected mouldings, a hollow peg formed integrally with a first of the mouldings, a pin formed integrally with the peg and, prior to *o :interconnection of the mouldings, protruding from the first moulding in a direction away from the peg. The pin 25 i, connected with the peg by way of a frangible connection and is drivable in a direction into the peg when the mouldings are being interconnected. A recess is formed integrally with a second of the mouldings and is aligned with the peg when the mouldings are interconnected. The recess is arranged to receive at least a portion of the peg, and the first and second mouldings are interconnected by locating at least a eportion of the peg within the aligned recess and by driving the pin into the hollow interior of the peg in a manner to cause th? peg to engage in an interference fit within the recess.

)4210 PO 2a Although the present invention could be arranged with the pin, peg and recess assuming a variety of shapes, it is preferred that the hollow within the peg and the pin be substantially cylindrical and further, that the peg and the recess are substantially cylindrical. More preferably, a portion of increased diameter at or near a first end of the peg forms a bulb and the recess has a correspondingly shaped portion of increased diameter to receive the bulb. In such an arrangement, the peg has a longitudinal slot extending P04210PO 3 from its first end to facilitace compression of the peg and location in the recess. Preferably, the peg will have two such longitudinal slots which are diametrically opposed.

Each of the mouldings will have an exposed face in the assembled electrical fitting and preferably, a portion of the pin projects through an aperture in the exposed face of the first moulding prior to breaking the frangible joint and driving the pin into the hollow peg.

Typically, the fitting has a plurality of pegs and frangibly connected pins, and a corresponding plurality of recesses arranged to receive the pegs, with all of the pegs integrally formed with the first moulding and all of the recesses integrally formed with the second moulding.

Further, it is preferred that both the first and second mouldings are moulded from polycarbonate, ABS styrene or an ABS styrene alloy.

The present invention will be more fully understood from the ensuing description of a preferred embodiment which is provided with reference to the accompanying drawings in which: Figure 1 is a perspective view of a four outlet power board having a cover plate and a base plate, Figure 2 is a plan view of the cover plate of the 25 power board illustrated in Figure 1, Figure 3 is a plan view of the base plate of the ".:power board illustrated in Figure i, Figure 4 is an inverted plan view of the base plate illustrated in Figure 3 prior to assembly of the power S 30 board, Figure 5 is an end elevation of the base plate illustrated in Figure 4, Figure 6 is a cross-section viewed along line A-A of Figure 4, Figure 7 is a cross-section viewed along line B-B of Figure 4, Figure 8 is an enlarged view of the encircled area of Figure 6, P04210-PO/429 4 Figure 9 is a complete end elevation of the enlarged cross-section illustrated in Figure 8, Figure 10 is cross-section viewed along line C-C of Figure 9, Figure 11 is an inverted plan view of the cover plate illustrated in Figure 2 prior to assembly of the power board, Figure 12 is a cross-section viewed along line D-D of Figure 11, Figure 13 is a cross-section viewed along line E-E of Figure 11, and Figure 14 is an enlarged view of the encircled area of Figure 13.

The power board 20 comprises a cover plate 21; a base plate 22; a power lead and associated three-pin power plug (not shown) which enter the power board through aperture 23; and earth, active and neutral busbars (not shown) which are housed within the cover plate 21 and base plate 22.

20 The cover plate 21 and base plate 22 are moulded :.i from polycarbonate and have exposed faces 24 and respectively which form the top and bottom of the power board. Upstanding peripheral walls 26 extend from the 25 faces 24 and 25 to form the sides of the fitting 20 and the front face 24 is provided with four three-pin power sockets 27 which are arranged to receive three-pin power plugs. The power board 20 is arranged to be either secured to a pair of screws by mounting recesses 28 or poEsitioned on a flat surface by feet 29 located at the 30 corners of face The fitting 20 can be assembled by placing the cover plate 21 on its face 24, positioning the busbars (not *.shown) within the cover plate 21 and attaching the power lead and associated three-pin plug (not shown). The base plate 22 is then placed on top of the cover plate 21 with its face 25 uppermost and the walls 26 approximately aligned.

The base plate 22 is then accurately positioned on P04210-P01429 the cover plate 21 by locating first ends 30 of the four hollow pegs 31 in the four correspondingly shaped recesses 32. The pegs 31 are integrally formed with the base plate 22 and the recesses 32 are integrally formed with the cover plate 21.

When the cover plate 21 and base plate 22 are so-positioned, the fitting is electrically tested to ensure that it operates appropriately. If the test result is negative, the base plate 22 can readily be lifted from the cover plate 21 and the problem investigated.

If however, the testing result is positive, downwards pressure is applied to each of the four pins 33 which project above the face 25 of the base plate 22 through counter-sunk apertures 34. The pins 33 are integrally formed with the pegs 31 and connected to the pegs 31 by frangible joints 35. Sufficient downwards pressure on the pins 33 breaks the frangible joints and drives the pins 33 through second ends 36 of the pegs 31 into the voids 37 within the pegs 31. The downwards pressure is applied until the tops of the pins 33 rest e neatly within the counter-sunk apertures 34 with the •eea :result that the pegs 31 are retained within the recesses o• 32 by a frictional fit.

Each of the pegs 31 has a pair of diametrically opposed longitudinal slots 38 extending from the first ends 30 towards the second ends 36. The slots 38 extend e for approximately 70% of the length of the pegs 31. A bulb 39 is formed near the first ends 30 of each peg 31 S 30 and each recess has a corresponding depression 40 of increased diameter arranged to receive the bulb 39. The apex of the bulbs 39 are the points of greatest diameter *.of the pegs 31 and this diameter is larger than the :diameter of the recesses 32 at their entrances 41. The pegs 31 taper from the apex of the bulbs 39 to their first ends 30 to allow location of the leading ends 30 at the entrances 41 of the recesses 32. Urging of the first ends 30 towards the bases 42 of the recesses 32 results P04210-P/01429 6 in compression of the longitudinal slots 38 and allows the bulbs 39 co pass through the openings 41 of the recesses 32. Continued movement of the pegs 31 toward the bases 42 of the recesses 32 results in the bulbs 39 aligning with the depressions 40 and the leading ends resting on the bases 42 of the recesses 32. Although the pegs 31 are resilient, the mere location of the bulbs 39 within the depressions 40 is not sufficient to secure the base plate 22 to the cover plate 21 and the two plates can be separated by pulling them apart; again with compression of the pegs 31 resulting from narrowing of the longitudinal slots 38.

To firmly secure the base plate 22 to the cover plate 21, the pegs are positioned within the recesses as previously mentioned and force is applied to the pins 33 to break the frangible joints 35. Once the frangible joints 35 have been broken, continued application of force to the pins 3 results in the pins 33 passing through the second erds 36 of the pegs 31 into the voids 37. Further application of force will drive the pins 33 completely into the voids 37 until the ends of the pins 33 rest on the bases 42 of the recesses 32. This action firmly forces the walls of the pegs 31 against the walls S"of the recesses 32 and in particular, forces the bulbs 39 15 into depressions 40. Once so secured, the base plate 22 cannot be removed from the cover plate 21 unless the pins 33 are drilled out from the voids 37. The pins 33 are ""sized such that once driven into the voids 37, one end rests on the base 42 of the recess 32 and the other end fits neatly within the counter-sunk recess 34 in the face of the base plate 22.

S.

P0421 O-P0/429

Claims

1. Arn electrical fitting comprising electrical components housed within interconnected mouldings, a hollow peg formed integrally with a first of the mouldings, a pin formed integrally with the peg and, prior to interconnection of the mouldings, protruding from the first moulding in a direction away from the peg, the pin being connected with the peg by way of a frangible connection and being drivable in a direction into the peg when the mouldings are being interconnected, a recess formed integrally with a second of the mouldings and being aligned with the peg when the mouldings are interconnected, the recess being arranged to receive at least a portion of the peg, and the first and second mouldings being interconnected by locating at least a portion of the peg within the aligned recess and by driving the pin into the hollow interior of the peg in a manner to cause the peg to engage in an interference fit within the recess.

2. A fitting as claimed in claim 1 wherein each moulding has an exposed face and a portion of the pin projects through an aperture in the expcsed face of the first moulding prior to breaking of the frangible connection and driving the pin into the hollow peg. 25

3. A fitting as claimed in claim 1 or claim 2 wherein the hollow interior of the peg and the pin are substantially cylindrical.

4. A fitting as claimed in any one of the preceding claims wherein the peg and the recess are substantially cylindrical.

5. A fitting as claimed in any one of the preceding claims wherein the hollow peg has a longitudinal slot extending from a first end of the peg, whereby the peg can be compressed by narrowing of the slot to facilitate location of the peg within the recess.

6. A fitting as claimed in claim 5 wherein the hollow peg has two diametrically opposed longitudinal slots extending from the first end of the peg. S *5 S S S **S S S R'J 021 OPO 8

7. A fitting as claimed in claim 5 or claim 6 wherein a region of the hollow peg is of increased diameter and a corresponding region of the recess is of similarly increased diameter.

8. A fitting as claimed in claim 7 wherein the area of increased diameter forms a bulb at or near the first end of the hollow peg.

9. A fitting as claimed in any one of the preceding claims having a plurality of said pegs and frangibly connected pins and a corresponding plurality of said recesses arranged to receive the pegs.

A fitting as claimed in claim 9 wherein all of the pegs are integrally formed with the first moulding and all of the recesses are integrally formed with the second moulding.

11. A fitting as claimed in any one of the preceding claims wherein tl, mouldings are moulded from polycarbonate, ABS styrene or an ABS styrene alloy.

12. A fitting as claimed in any of claims 2-11 20 wherein upstanding peripheral walls extend from the edges of the exposed faces of each moulding and meet to form the sides of the fitting, the first moulding forming a base plate of the fitting, and the second moulding forming a cover plate of the fitting. 25

13. A fitting as claimed in any one of the preceding claims wherein the fitting incorporates a plurality of power sockets arranged to receive power plugs and wherein the electrical components comprise a neutral busbar, an S'active busbar and an earth busbar, the second moulding having apertures formed in an exposed face Df the moulding, the apertures being arranged to receive pins of the power plugs and being aligned with the power sockets within the mouldings.

14. A power board substantially as herein described with reference to the accompanying drawings. DATED this 19th day of September 1995 SHPM INDUSTRIES PTY LIMITED SBy its Patent Actorneys Sl ZY GRIFFITH HACK CO P04210PO Abstract An electrical fitting comprises electrical components sandwiched between interconnected mouldings. A series of hollow pegs are integrally formed with one of the mouldings and a pin is frangibly connected to each peg. A series of recesses are integrally formed with another of the moulding and are arranged to receive the pegs. The mouldings are interconnected by locating the pegs with the recesses and driving the pins into the pegs to retain the pegs within the recesses. o* e *o