GB2278238A

GB2278238A - Indicators and pushbuttons

Info

Publication number: GB2278238A
Application number: GB9409639A
Authority: GB
Inventors: James Frederick Edwards
Original assignee: DEWHURST PLC
Current assignee: DEWHURST PLC
Priority date: 1993-05-19
Filing date: 1994-05-13
Publication date: 1994-11-23
Anticipated expiration: 2014-05-13
Also published as: CA2123819A1; GB9409640D0; GB2278239B; GB9409639D0; GB9310265D0; GB2278238B; GB2278239A

Abstract

An illuminable member for an indicator or pushbutton comprises a translucent or transparent carrier 12 with which a cover member 10 is arranged to engage. The carrier 12 comprises a plate 24 and is retained relative to a housing of the indicator or pushbutton during manufacture. When the indicator or pushbutton is to be mounted in its in use location, an appropriate cover member 10 is engaged with the carrier 12. The cover member 10 may be plain or carry selected indicia. To facilitate the engagement, the cover member 10 carries spaced projections 20 which engage in slots in the carrier 12. Flanges 22 of the projections 20 prevent removal of the cover member 10 from the front of the completed and installed indicator or push button. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO INDICATORS AND PUSHBUTTONS The present invention relates to an illuminable indicator or pushbutton, to members for such indicators and pushbuttons, and to methods of making indicators or pushbuttons.

Pushbutton switches, for example, are provided in a variety of locations, such as in lifts. It is frequently required to provide illumination thereto, for example, to indicate that the switch has been operated or to facilitate use of the pushbutton. It is known to illuminate such switches by providing an illuminated halo surrounding the pushbutton. A construction of a pushbutton switch having such a halo effect is described in our earlier UK Patent No. 1456391.

It is also known to provide illuminable indicators, for example, to show the current floor location of a lift.

Our UK Patent No. 2148574 shows such an indicator in which material has been removed from an opaque cover plate to form the indicia to be illuminated.

It is, of course, useful to provide indicia on pushbutton pressel plates and to arrange that these are illuminated. However, this leads to complications in the assembly of the pushbutton switches in that each pushbutton switch has to have the required indicia on its pressel plate. This means that the final function of the pushbutton assembly, including the indicia required on the pressel plate, has to be known before the pushbutton assembly is manufactured.

According to a first aspect of the present invention there is provided an illuminable indicator or pushbutton member comprising a carrier, and a cover member interengaged with said carrier, wherein said carrier comprises a plate, and interengaging means provided on said plate, wherein said cover member comprises a body member having an external surface, and interengaging means cooperable with those of said carrier to retain said cover member on said carrier to extend over said plate, wherein the cover member is arranged to be engaged with the carrier subsequent to the mounting of the carrier in an indicator or pushbutton.

Preferably, said carrier plate and said body member are formed of a material which is pervious to light.

An indicator or pushbutton member of an embodiment of the invention comprises the carrier and the cover member and both of these may be standardised components. As the cover member is arranged to be engaged with the carrier subsequent to the mounting of the carrier in an indicator or pushbutton, the indicators and pushbuttons can be manufactured without reference to their final function.

When the indicator or pushbutton is to be mounted in its use location, an appropriate cover member can be selected and engaged with the carrier. The cover member selected would carry the required indicia, or be plain, to suit the location chosen for the indicator or pushbutton. In this respect, the cover members are relatively small and low cost components and a large number can be held in store, the stored components having a wide range of differing indicia. This enables the assembly of a large range of different indicators and pushbuttons using the stored components.

Furthermore, the invention enables the provision of both pushbuttons and indicators utilising the same cover members. In this respect, the housing for the pushbuttons and the indicators may be arranged to house a standardised carrier, or two different types of carrier may be provided, but each arranged to receive an identical cover member.

This also reduces the number of individual components which need to be made and stored in order to offer a wide range of final assemblies. The construction also enables an indicator, for example, to be provided with halo illumination as has become common with pushbuttons.

The material of said carrier plate and of said body member may be translucent or transparent. Preferably, the material is translucent. In this respect, it is preferred that the carrier plate and the body member both be made of a polycarbonate plastics material.

Any appropriate cooperable interengaging means may be provided on said carrier plate and on said body member.

For example, one of the carrier plate or body member may have spring projections arranged to engage within respective recesses in the other of the body member or carrier plate and/or spring clips may be formed on the carrier plate or body member and arranged to engage with rebates and/or projections formed on the body member or carrier plate.

However, to facilitate the provision of a standardised cover member for use in many different applications, it is preferred that the body member comprises a substantially planar wall on which said external surface is defined and a peripheral skirt depending from said planar wall away from said external surface. In this case it is convenient for the interengaging means carried by said body member to comprise resilient projections projecting from or formed within said peripheral skirt. The cooperable interengaging means of said carrier preferably comprise slots extending through said carrier plate into which a corresponding resilient projection may be received.

Preferably, each said resilient projection is provided with a flange arrange to clip onto or engage with part of the respective slot in said carrier plate to retain the cover member thereon.

The cooperable interengaging means are arranged to retain the cover member on the carrier such that, once assembled, the cover member cannot be released from the front of an indicator or pushbutton in use.

In an embodiment, the interengaging means are arranged so that the cover member may be retained on said carrier in a selected one of at least two positions. For example, two oppositely arranged resilient projections may be provided on said cover member whereas two pairs of opposed spaced slots are provided in said carrier plate. The projections of the cover member may then be engaged with a selected one of the pairs of slots and thereby engaged in a selected one of two orientations.

The cover member may be of any peripheral shape Preferably, the cover member is substantially circular or is substantially square in perimetral shape.

In an embodiment, the plate of said carrier has at least one aperture extending therethrough around which the interengaging means on said plate are provided. In this case, said cover member is retained on said carrier to extend over said aperture or apertures.

Preferably, the carrier plate is provided with a single aperture only. Preferably the aperture is substantially the same shape as the cover member. Thus, the aperture may be substantially circular or substantially square in shape.

The carrier has to be retained relative to a housing of an indicator or a pushbutton and is therefore suitably shaped to fit the housing and may carry appropriate fixing or retention means. In this respect, in some circumstances it may be sufficient to sandwich the carrier with other components to reliably retain it, and in other embodiments a more positive retention may be preferred. Where the carrier is to be provided in a pushbutton, for example, it may also need to provide fixing or location means for springs and/or switch members. Furthermore, a pushbutton member may require guide means to control its movement relative to a housing. Of course, the retention, location, and guide means may be shaped and configured as appropriate.

In a preferred embodiment, the carrier plate has a single aperture and has a rim which extends around said aperture. Preferably, the shapes of said rim and of said aperture are substantially the same. The slots forming the interengaging means may be provided in said carrier plate within said rim and around said aperture. Appropriate retention, location and guide means extend externally of said rim. Such means may extend substantially in the same plane as the carrier plate and/or at angles thereto.

In a preferred embodiment, the external dimension of the peripheral skirt of the body member of said cover member is somewhat larger than the external peripheral dimension of the cover plate. However, the external dimension of the peripheral skirt is chosen such that the peripheral skirt fits within the rim on said carrier plate.

With this arrangement, the rim of the carrier plate may form a peripheral shoulder surrounding the cover member in the indicator member or pushbutton member. This facilitates the provision of halo illumination around the cover plate.

In known manner, the cover plate, which is preferably made of stainless steel, is fixed to said body member during moulding thereof. Preferably, any indicia are formed by cutouts through the cover plate which become filled with the material of the body member during moulding thereof. Preferably the internal surface of the planar wall of the body member is formed to define a plurality of reflective surfaces to enhance the illumination effect.

The present invention also extends to an illuminable indicator or pushbutton comprising a housing in which illuminating means are received, said housing having a front opening, and said housing being arranged to support the carrier of an illuminable indicator or pushbutton member as defined above in or proximate to the front opening such that light from said illuminating means is directed towards said carrier plate and said body member.

The housing may be configured as appropriate to enable the indicator or pushbutton to be mounted in any required wall or panel. Furthermore, switches and/or other actuable means may be carried and/or supported by the housing of the pushbutton.

The illuminating means may be configured and supported as required. For example, the illuminating means may comprise a light bulb supported by a bulb holder, the bulb being connected to electrical terminals supported by the housing.

In an alternative embodiment, the illuminating means may comprise a number of LEDs appropriately mounted and connected by way of an electrical circuit to electrical terminals. In a preferred embodiment, the LEDs may be mounted and supported on a printed circuit board.

Preferably, the bulb holder and the printed circuit board are arranged to be interchangeably mounted in said housing.

In an embodiment, the carrier is retained relative to the housing by fixing or retention means which are sandwiched between components of the assembly to reliably retain the carrier.

In an alternative embodiment, said carrier provides fixing or location means for springs and/or switch members, and wherein said carrier has guide means to control its movement relative to said housing.

The present invention also extends to a method of manufacturing an illuminable indicator or pushbutton, the method comprising the steps of assembling illuminating means in a housing having a front opening, supporting any further required components on the housing, and supporting the carrier of an illuminable member as defined above in or proximate to said front opening, and, upon completion of the assembly, engaging a selected cover member on said carrier.

Preferably, the opaque cover plate of said cover member comprises a selected indicia or is plain.

According to a further aspect of the present invention there is provided a method of manufacturing an illuminable indicator or pushbutton, the method comprising the steps of assembling illuminating means in a housing having a front opening, supporting any further required components on the housing, and supporting a carrier of an illuminable member across said front opening, and, upon completion of said assembly, engaging a selected cover member on said carrier, said cover member carrying selected indicia or being plain.

Preferably, said cover member is selectively engaged in one of two possible orientations in relation to said carrier.

The invention also extends to an electrical pushbutton switch assembly comprising a housing having a base and an upstanding peripheral wall, a pair of electrical switches supported generally opposite to each other on said peripheral wall and each having an upstanding, reciprocal, resiliently mounted, switching member, and a pushbutton member, as defined above, supported within said peripheral wall for reciprocable movement relative to said housing, said pushbutton member having two switching projections each arranged in contact with a respective switching member such that reciprocable movement of said pushbutton member causes reciprocation of said switching members, wherein, the housing and the pushbutton member are configured such that the reciprocable movement of the pushbutton member is within said housing, and such that the overall height of the housing is generally substantially the same as the height of each said switch including its switching member.

Reciprocation of the pushbutton member within the housing between the switches is enabled by providing for guiding of the reciprocal movement of the pushbutton member at two opposed areas thereof only.

Embodiments of the present invention will hereinafter be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a front view of a pushbutton switch assembly of the present invention, Figure 2 shows a plan view of the assembly of Figure 1, Figure 3 shows a section of the switch assembly of Figures 1 and 2 taken along the line BB of Figure 2, Figure 4 shows a section of the switch assembly of Figures 1 and 2 taken along the line AA of Figure 2, Figure 5 shows a perspective view from underneath of a carrier plate of a pushbutton member of the switch assembly, and Figure 6 shows a perspective view from underneath of a pressel member for interengagement with the carrier plate of Figure 5.

The drawings illustrate, and the present invention will be described, with reference to a pushbutton switch assembly. However, it should be appreciated that the illuminable pushbutton member provided in the switch assembly may also be used as an illuminable indicator member. In this respect, to provide an illuminable indicator it is necessary only to fix the illuminable indicator member relative to a housing.

The electrical pushbutton switch assembly shown in the drawings is specifically designed for use in lifts but, of course, may be used in any situations where pushbutton operation is required. The particular switch assembly illustrated is illuminable. As compared with prior art switch assemblies, the switch assembly described herein is more shallow and considerably more compact. Furthermore, the pushbutton member of the switch assembly described herein comprises a standardised cover member carrying selected indicia which may be fitted into the switch assembly at the last stage of manufacture. The cover member may be selectively oriented and may be selected to carry the required indicia, or be plain, to suit the location chosen for the pushbutton switch assembly.

Figure 1 illustrates a pushbutton switch assembly mounted in situ. In this respect, the switch assembly has a housing 2 which in use is mounted behind a door or panel skin 4 (not visible in Figure 1) by way of mounting screws 6. The switch assembly is mounted so that a cover or pressel plate 8 of a reciprocable cover or pressel member 10 is visible and accessible to a user. The pressel plate 8 is surrounded by a halo of translucent material provided by the pressel member 10 and by a carrier 12 therefor. In use, the switch assembly is illuminated so that a halo of illumination surrounds the pressel plate 8. In Figure 1, the pressel plate 8 is plain. However, illuminable indicia can be provided on the pressel plate 8 if required.

As can be seen in Figures 3, 4 and 6, the pressel member 10 comprises a body member 14 which is preferably made of a translucent polycarbonate plastics material. The body member 14 is substantially square in shape and has a substantially square, substantially planar base wall 16 from which an upstanding, peripheral skirt 18 depends. On the front, external surface of the base wall 16 the pressel plate 8 is fixed. In known manner the body member 14 is fixed to the pressel plate 8 during moulding of the body member. If the pressel member 10 is to carry indicia, appropriate cutouts are made in the pressel plate 8 before the moulding operation. The translucent plastics material then fills the cutouts in the plate 8 in known manner.

Preferably, the pressel plate 8 is made of stainless steel.

The pressel member 10 is engaged with the carrier 12.

To facilitate this, on two sides the body member 14 of the pressel member 10 is formed to provide resilient clips 20.

As can be seen in Figures 3 and 6, each clip 20 is a resilient projection projecting from and formed within said peripheral skirt 18. Each projection 20 is provided with a flange 22 for engagement with a respective slot in the carrier 12.

The carrier 12 is also preferably made of a translucent polycarbonate plastics material and is arranged to guide the body member 14 for reciprocable movement within the switch housing 2 and also to enable the halo illumination around the pressel plate 8. Furthermore, it is the carrier 12 which switches the individual switches within the switch assembly.

A perspective view from underneath of the carrier 12 is shown in Figure 5. The carrier 12 comprises a substantially square carrier plate 24. This carrier plate has an external upstanding rim 26 as can be seen in Figure 4. Centrally of the plate 24 there is provided a substantially square aperture 28 and adjacent each side of the aperture 28 there is provided a respective slot 30.

These slots 30 define interengaging means for cooperating with the clips 20 on the body member 14. In this respect, the pressel member 10 is generally provided with two opposed clips 20. It will therefore be appreciated that the pressel member 10 may be oriented selectively by engaging the clips 20 in a selected one of the two pairs of opposed slots 30. When the pressel member 10 is engaged with the carrier plate 24, by way of the clips 20, part of the translucent body member 14, and the rim 26 of the carrier plate 24, extend outwardly of, and surround the periphery of the pressel plate 8 as can be seen in Figure 4. This provides, in use, and in known manner, an illuminable halo around the pressel plate 8. This, together with the engagement between the flanges 22 and the slots 30, also ensures that the pressel member 10 cannot be removed from the switch assembly from the front thereof.

The carrier plate 24 is guided for reciprocating movement within the housing 2 by guide means 34 provided on two opposed surfaces of the carrier plate 24. As indicated in Figures 2, each guide means 34 comprises an elongate channel member depending from the carrier plate 24 and having a base surface formed between two upstanding walls 36 defining longitudinally extending projections. The projections 36 are received in corresponding longitudinally extending recesses (not visible) in the housing 2 to guide the carrier 12 for reciprocal movement along the longitudinal axis of the switch assembly.

On its other two sides, the carrier plate 24 is provided with switching projections 40. Each switching projection 40 is formed by a flange extending substantially in the plane of the carrier plate 24, and extending along the respective side of the carrier plate 24. Each said flange carries a protuberance 42 for contacting a plunger of an individual switch and a projection 44 for locating a bias spring 62 (Figure 4). In this respect, in known manner depression of the pressel member 10 is arranged to cause depression of the carrier 12 whereby plungers of the individual switches carried by the housing 2 will be depressed, by way of the protuberances 42. When the pressure is released, bias springs located by the projections 44 will push the carrier 12, and hence the pressel member 10 to the outward rest position, the plungers also being biassed to be returned by spring force.

One of the individual switches 50, which is a normally closed switch, of the pushbutton switch assembly, can be seen in Figure 3. The switch 50 is a substantially conventional construction and comprises a moveable contact 52 normally held against individual fixed contacts 54 by way of a spring 56. The moveable contact 52 is connected to the spring 56 and also to a plunger 58. The plunger 58, which is the switching member of the switch 50, projects upwardly to contact the underside of one of the protuberances 42 of the carrier 12. It will be appreciated that depression of the plunger 58 will open the contacts 52, 54 and move the moveable contact 52 into contact with a lower contact 60.

The switch assembly shown in the drawings is particularly shallow and compact. In this respect the overall height of the switch assembly is generally substantially the same as the overall height of an individual switch 50 when its plunger 58 is in its upper rest position. All of the necessary reciprocating movement of the carrier 12 takes place within the housing 2 and this leads to the compact construction illustrated.

The compact construction is also enabled because the carrier 12 is guided for reciprocating movement along two only of its sides. This means that no guiding function has to be provided on sides of the carrier 12 which contact the switch plunger 58 and the bias springs 62. Guidance can be provided at two opposed areas of the carrier 12 only because of the provision of the channels 34, the longitudinally extending walls 36 of which are each received within a respective recess in the wall of the housing 2. These recesses extend over substantially the entire height of the housing 2 so that the carrier 12 remains guided irrespective of its location along the height of the housing 2. Preferably, the recesses are defined between projecting surfaces of the housing 2 which are also arranged to abut against the base of the respective channel 34. This ensures that there is no ability for twist to be introduced into the reciprocating movement of the carrier 12.

The manner in which the housing 2 is constructed also enables it to be made compact. In this respect the housing 2 is preferably moulded from a polycarbonate plastics material and is moulded in two parts. The first part is a substantially planar base 70 which is integrally formed with part of a housing 72 for each of the two switches 50.

In this respect, the switch housings 72 each have a clipped on side wall 74 and are generally rectangular. The housings each project upwardly of the base 70 on two sides thereof.

In its central region the base 70 holds a bulb 80 carried on a bulb holder 82 for which appropriate electrical terminals 84 are also provided. The bulb 80 extends substantially centrally within the housing 2 and provides illumination directed at the underside of the base wall 16 of the body member 14 of the pressel member 10. In the embodiment illustrated, the bulb holder 82 also carries a reflector 90 to surround the bulb 80 and direct the light. If required, the bulb holder 82 with its bulb 80 and terminals 84 may be replaced by an illumination printed circuit board carrying LEDs and appropriate electrical terminals.

To complete the formation of the housing 2 the base 70 is engaged with a moulded body 100. The body 100 is also preferably moulded from a polycarbonate plastics material.

This body 100 is a generally rectangular hollow member having a perimeter rim. On two sides the interior surface of the perimeter rim is formed with the necessary longitudinally extending recesses for receiving the walls 36 of the channel members 34 of the carrier 12 to provide the necessary guidance. The body 100 is also formed with bores or apertures through which the plungers 58 extend. A central bore is also provided through which the bulb 80 projects. The body 100 is also formed with locating points for the bias springs 62. The body 100 and the base 70 are interengaged such that the perimeter rim of the body 100 and the switch housing 72 together define a generally upstanding peripheral wall of the housing 2, and a front opening in which the pressel member 10 is mounted.

It will be appreciated that the switch assembly having two plunger operated switches controlled by the depression of a pressel member 10 is substantially conventional in the functioning components provided and in its manner of operation and so the operation of the switch assembly will not be further described.

It will be appreciated that modifications in and variations to the embodiments specifically described and illustrated may be made within the scope of this application.

Claims

1. An illuminable indicator or pushbutton member comprising a carrier, and a cover member interengaged with said carrier, wherein said carrier comprises a plate, and interengaging means provided on said plate, wherein said cover member comprises a body member having an external surface, and interengaging means cooperable with those of said carrier to retain said cover member on said carrier to extend over said plate, wherein the cover member is arranged to be engaged with the carrier subsequent to the mounting of the carrier in an indicator or pushbutton.

2. An illuminable indicator or pushbutton member as claimed in Claim 1, wherein said carrier plate and said body member are formed of a material which is pervious to light.

3. An illuminable indicator or pushbutton member as claimed in Claim 2, wherein said cover member further comprises an opaque cover plate fixed to said external surface of said body member.

4. An illuminable indicator or pushbutton member as claimed in Claim 2 or Claim 3, wherein the material of said carrier plate and of said body member is translucent polycarbonate plastics material.

5. An illuminable indicator or pushbutton member as claimed in any preceding claim, wherein said cooperable interengaging means provided on said carrier plate and on said body member comprises spring projections on one of said carrier plate or body member arranged to engage within respective recesses in the other of said body member or carrier plate.

6. An illuminable indicator or pushbutton member as claimed in Claim 5, wherein said body member comprises a substantially planar wall on which said external surface is defined and a peripheral skirt depending from said planar wall away from said external surface, and wherein the interengaging means carried by said body member comprise resilient projections projecting from or formed within said peripheral skirt, and the cooperable interengaging means of said carrier plate comprise slots extending through said carrier plate into each of which a corresponding resilient projection may be received.

7. An illuminable indicator or pushbutton member as claimed in Claim 6, wherein each said resilient projection is provided with a flange arranged to clip onto or engage with part of the respective slot in said carrier plate to retain the cover member thereon.

8. An illuminable indicator or pushbutton member as claimed in any preceding claim, wherein the cooperable interengaging means are arranged so that the cover member may be retained on said carrier in a selected one of at least two positions.

9. An illuminable indicator or pushbutton member as claimed in any preceding claim, wherein the carrier plate is provided with an aperture extending therethrough, and wherein the aperture is substantially the same shape as the perimetral shape of the cover member.

10. An illuminable indictor or pushbutton comprising a housing in which illuminating means are received, said housing having a front opening, and said housing being arranged to support the carrier of an illuminable indicator or pushbutton member as claimed in any of Claims 1 to 10 in or proximate to the front opening such that light from said illuminating means is directed towards said carrier plate and said body member.

11. An illuminable indicator or pushbutton as claimed in Claim 10, wherein the illuminating means comprises a light bulb supported by a bulb holder, the bulb being connected to electrical terminals supported by the housing.

12. An illuminable indicator or pushbutton as claimed in Claim 10, wherein the illuminating means comprises a number of LEDs mounted and supported on a printed circuit board and connected by way of an electrical circuit to electrical terminals.

13. An illuminable indictor or pushbutton as claimed in any of Claims 10 to 12, wherein the carrier is retained relative to the housing by fixing or retention means which are sandwiched between components of the assembly to reliably retain the carrier.

14. An illuminable indicator or pushbutton as claimed in any of Claims 10 to 12, configured as a pushbutton, wherein said carrier provides fixing or location means for springs and/or switch members, and wherein said carrier has guide means to control its movement relative to said housing.

15. A method of manufacturing an illuminable indicator or pushbutton, the method comprising the steps of assembling illuminating means in a housing having a front opening, supporting any further required components on the housing, and supporting the carrier of an illuminable member as claimed in any of Claims 1 to 9 in or proximate to said front opening, and, upon completion of the assembly, engaging a selected cover member on said carrier.

16. A method of manufacturing an illuminable indicator or pushbutton, the method comprising the steps of assembling illuminating means in a housing having a front opening, supporting any further required components on the housing, and supporting a carrier of an illuminable member across said front opening, and, upon completion of said assembly, engaging a selected cover member on said carrier, said cover member carrying selected indicia or being plain.

17. A method as claimed in Claim 16, wherein said cover member is selectively engaged in one of two possible orientations in relation to said carrier.

18. An illuminable indicator or pushbutton member substantially as hereinbefore described with reference to the accompanying drawings.

19. An illuminable indicator or pushbutton substantially as hereinbefore described with reference to the accompanying drawings.

20. A method of manufacturing an illuminable indicator or pushbutton, substantially as hereinbefore described with reference to the accompanying drawings.