AU617093B2

AU617093B2 - Improvements in/or relating to electrical switch gear

Info

Publication number: AU617093B2
Application number: AU82188/87A
Authority: AU
Inventors: David Langman Cook
Original assignee: PDL Holdings Ltd
Current assignee: PDL Holdings Ltd
Priority date: 1986-12-09
Filing date: 1987-12-07
Publication date: 1991-11-21
Anticipated expiration: 2007-12-07
Also published as: GB2199446B; MY102650A; NZ218564A; AU8218887A; GB8728685D0; GB2199446A

Description

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AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

317093 Int. Class Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: 0 0 Priority Related Art: 0 6 00 APPLICANT'S REFERENCE: P149828 Name(s) of Applicant(s): PDL Holdings Limited Address(es) of Applicant(s): 14 Hazeldean Road, 0 0 Christchurch 2, NEW ZEALAND.

Address for Service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled: IMPROVEMENTS IN/OR RELATING TO ELECTRICAL SWITCH GEAR Our Ref 77406 POF Code: 1358/10281 The following statement is a full description of this invent' including the best method of performing it known to applicant(s): 6003q/l 1 -2- This invention relates to a switching assembly.

Domestic and light industrial switches are mounted in a mounting plate which is fixed to a box located in a wall or similar structure. It is sometimes desirable to have a facility whereby the switch modules can be removed from the mounting plate. With the existing designs of sucih module o'.o switches at present available, the module unit is mounted from the rear of the o plate. These switch modules clip into place in an aperture in the mounting plate but because of the rear loading, any significant force applied to the Sfront of the switch may cause the switch module to disengage from the plate.

To provide suitable protection against this occurrence, additioral fixing means, usually in the form of screws, are inserted. This means of mounting is not entirely satisfactory both because the unit is still subject to displacement by heavy front loading particularly impact loading and in any S event, the switch modules can be comparatively easily removed by an T unauthorised person with the use of a simple tool such as a screwdriver blade.

It is proposed with the present invention to provide a front mounting switch module. This will mean a construction that is better designed to resist displacement from impact on the face of the switch. As an ancillary feature, it is intended to provide a mounting which will be difficult to disengage without the assistance of a module ejector. This will tend to ensure only qualified tradespersons are able to remove the switch modules from the mounting plate.

In the specification the "switch module" it is intended to encompass the housing in which will hold the switch components or other ancillary equipment that can be used on a mounting plate. As an example of such ancillary equipment, it is intended to include a neon unit, a press switch, an infra-red controlled switch, a cord outlet, an attachment for a hi-fi speaker or television aerial, a fused unit, a pull cord switch and a cord outlet. These are intended to be ill.ustrative and not exhaustive of the type of ancillary equipment that can be mounted in a housing module for use in association with the mounting plate. Also it would be part of the design to provide a blank which can be used to fill an opening in a plate where no switch module or ancillary unit is to be used.

According to the present invention there is provided a flush mountable electric switch assembly, comprising a mounting plate defining an opening to receive and flush mount a removable module, and a removable module having a a: 15 housing with mounting means to locate and engage it in the a opening in the mounting plate, characterised in that the S1a: mounting plate defines the opening with a peripheral stepped recess extending in from the top face of the mounting plate about the opening, and having integral S 20 throat members forming opposed shoulders on the under surface of said throat member below the recess and an integral skirt dependent from the back of the mounting plate surrounding the opening and immediately on the inside of the opposed shoulders, the housing of the removable module having a peripheral lip to engage in the i ,stepped recess surrounding the opening in the mounting plate and the mounting means comprising opposed mounting arms extending up from the base of the housing, the arms being resiliently deformable when the module is inserted in the opening from the front face of the plate and adapted to pass the throat members and spring back with top parts of the arms engaging the shoulders and fitting in close proximity to the dependent skirt to thereby hold the module in place in the mounting plate, the skirt and the mounting arms being arranged such that an ejector socket with thin walls inserted between the skirt and the mounting arms will receive support from the skirt while compressing the mounting arms to allow the module to be I hdisengaged from the mounting plate AJt A- 3 Further the present invention provides mountable electric switch assembly having an ejector socket with thin walls arranged to engage in the position between the skirt and the mounting arms so that when the ejector socket is inserted and a force is applied to move the ejector socket towards the rear of the mounting plate, so that the mounting arms will be compressed to assume a position that will allow the module to be disengaged from the mounting plate, the ejector socket walls will receive support from the skirt while compressing the mounting arms One preferred form of the invention and a modification thereof will now be described with reference to the accompanying drawings in which: K Figure 1 is a diagrammatic view showing part of the 15 mounting plate with the switch module ready to be inserted therein, g m -3a- 4 Figure 2 shows the switch module partially inserted in the mounting plate, Figure 3 shows the switch module inserted in place, Figure 4 shows a partial sectional view through one side of the opening in the mounting plate and the corresponding part of a modified switch module when the switch module is partially in place, and i Figure 5 shows the alternate form of the invention when the switch module is fitted in place.

In the preferred form of the invention a switch module 1 is constructed so that it contains the necessary electrical componentry and as has been S 10 previously explained it is intended in this specification that the term "switch module" should be interpreted to include other ancillary equipment which may be usefully mounted in a mounting plate.

SThe housing 2 of the switch module is a moulded plastic housing preferably i moulded from some suitable grade of plastic, normally a suitable nylon. The housing 2 contains the switch components. These are not illustrated in the Vpresent drawings but are described and claimed in our New Zealand Patent Specification No. 218564.

The mounting plate 3 is a normal flush mounting plate designed to be attached to a box fixed in a wall or similar structure in accordance with the requirements of the regulatory authority in the country concerned. The plate may have one or a plurality of apertures each to receive a switch module and these apertures can be arranged in any convenient pattern.

Each opening 4 has a peripheral recess 5 extending in from the top face 6 of the mounting plate. Throat members 7 below the recess 5 project into the opening 4 creating shoulders 8 on the under surface thereof. A skirt 9 projects down from the under surface of the plate.

The housing 2 has a top lip 10 designed in use to engage in the recess 0o so that the top of the switch module will be flush or substantially flush with o the top 6 of the plate 3 as is illustrated in Figure 3. The housing below the o: lip 10 is cut away with resilient arms 11 and 12 rising upwardly and extending 1° outwardly from the base of the housing. The top 13 of the arms 11 and 12 is 10 arranged in use to engage beneath the shoulder 8 when the module is fitted in place again as is illustrated in Figure 3.

0 fit The switch module is inserted from the front of the plate 3. The throat Sa members 7 compress thq resilient arms 11 and 12 as is illustrated in Figure 2.

The switch module when inserted fully as shown in Figure 3 allows the arms 11 and 12 to spring back with the ends 13 under the shoulders 8. The arms are preferably still slightly compressed to assist in firmly holding the switch module in place. Preferably two arms are provided on each side of the switch.

This is not critical but it is a more desirable configuration.

When it is necessary to remove the switch module from the mounting plate, a module ejector is employed. This comprises a substantially square socket having a skirt designed to engage with the arms 11 and 12. The arms have an inclined face 14 which will be engaged by the skirt of the ejector. As the skirt is moved up the incline, it will move into the space defined by the skirt 9 dependent from the mounting plate 3. The skirt of the ejector can be comparatively thin because when it moves into association with the skirt 9 it -6is supported and further movement upwardly causes the ejector skirt to compress the resilient arms 11 and 12 to a configuration essentially as illustrated in Figure 2 thereby allowing the switch module to be moved from the mounting plate. While a comparatively simple form of ejector is able to remove the switch module, it is a specialist tool and without that specialist tool it would be very difficult to remove the switch module from the mounting plate.

The preferred form of invention described above has certain advantages in that it allows a material to be selected which is not subjected to any significant stress during use but it does require a tolerance in manufacture and does not allow any adjustments in thickness of the switch mounting plate.

In certain cases where a degree of adjustment is desirable or the stress loading applied to the material was not considered so critical or special material was available to withstand high stress loading, a construction as illustrated in Figures 4 and 5 could be employed.

In this instance, the mounting plate 3, throat members 7, recess shoulders 8 and skirt 9 are the same as previously described. In the case of the housing 2 the resilient mounting arm 12a has a different configuration at the head 15. The head 15 has a serrated or stepped upper surface 16. In this instance because of the serrated upper surface 15 there would be a range of positions where the switch unit could be engaged with the shoulder 8. As will be seen from the configuration adopted in Figure 4, the head 15 is deformed substantially to allow a disposition to be assumed which will enable the head to pass the throat members 7. This deformation stresses to a substantial degree the material in the arm 3 and it is for this reason that care needs to be exerted in selecting the material if such a configuration is adopted.

7 With the present invention either mode of the switch module can be inserted into the mounting plate from the front to provide an aesthetically pleasing and very strong assembly.

In use, a tradesperson has the capacity to easily remove the switch module so that it can be replaced if defective, It can be adjusted in position, it a can be replaced by one of the ancillary units, it can have a blank inserted 0 00 o°o where it had been removed or it can be inserted in position where a blank was o previously fitted. There is thus a great range of flexibility and a strong 0 t safe assembly is provided. From a practical point of view, the above described construction has the advantage that it can be manufactured using simpler dyes on the plate section because there are not undercut areas needed to provided 0 the retention legs as are necessary with rear mounted switch modules.

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Claims

1. A flush mountable electric switch assembly, comprising a mounting plate defining an opening to receive and flush mount a removable module, and a removable module having a housing with mounting means to locate and engage it in the opening in the mounting plate, characterised in that the mounting plate defines the opening with a peripheral stepped recess extending in from the top face of the mounting plate about the opening, and having integral throat members forming opposed shoulders on the under surface of said throat member below the recess and an integral skirt dependent from the back of the mruunting plate surrounding the opening and immediately on the inside of the opposed shoulders, the housing of the removable module having a peripheral lip to engage in the stepped recess surrounding the opening in the mounting plate and the mounting means comprising opposed mounting arms extending up from the base of the housing, the arms being resiliently deformable when the module is inserted in the opening from the front face of the plate and adapted to pass the throat members and spring back with top parts of the arms engaging the shoulders and fitting in close proximity to the dependent skirt to thereby hold the module in place in the mounting plate, the skirt and the mounting arms being arranged such that an ejector socket with thin walls inserted between the skirt and the mounting arms will receive support from the skirt while compressing the mounting arms to allow the module to be disengaged from the mounting plate

2. An assembly as claimed in claim 1, wherein the opposed mounting arms are arranged with two on each side of the housing.

3. An assembly as claimed in claim 1 or claim 2, wherein each mounting arm is integrally moulded with the housing and extends upwardly from the housing to terminate in an end designed to engage a shoulder in the mounting plate.

4. An assembly as claimed in claim 1 or claim 2, -8- wherein the mounting arms terminate in a head having a Vseries of serrations or indentations on a top face thereof ji to allow for engagement in one of a plurality of positions with the shoulder in the mounting plate.

A flush mountable electric switch assembly, comprising a mounting plate defined an opening to receive and flush mount a removable module, and a removable module having a housing with mounting means to locate and engage it in the opening in the mounting plate, characterised in that the mounting plate defines the opening with a peripheral stepped recess extending in from the top face of the mounting plate about the opening, and having integral throat members forming opposed shoulders on the under surface of said throat member below the recess and an integral skirt dependent from the back of the mounting plate surrounding the opening and immediately on the Kinside of the opposed shoulders, the housing of the removable module having a peripheral lip to engage in the stepped recess surrounding the opening in the mounting plate and the mounting means comprising opposed mounting V arms extending up from the base of the housing, the arms K being resiliently deformable when the module is inserted in the opening from the front face of the plate and adapted to pass the throat members and spring back with A top parts of the arms engaging the shoulders and fitting i in close proximity to the dependent skirt to thereby hold the module in place in the mounting plate, and an ejector socket with thin walls arranged to engage in the position K 30 between the skirt and the mounting arms so that when the ejector socket is inserted and a force is applied to move the ejector socket towards the rear of the mounting plate, so that the mounting arms will be compressed to assume a position that will allow the module to be disengaged from the mounting plate, the ejector socket walls will receive support from the skirt while compressing the mounting arms.

6. An assembly as claimed in any of the preceding 9 i LL claims, wherein the module is a switch module.

7. An assembly when constructed, arranged and operable substantially as herein described with reference to the accompanying drawings. DATED: 4 September 1991 PHILLIPS ORMONDE FITZPATRICK Attorneys for: PDL HOLDINGS LIMITED A 9 Oak^-^ a Io 1s I 0* 1731Z 10