GB2044003A - Actuators for electrical switches - Google Patents

Abstract

A switch actuating device comprises a manually operable actuator 7 supported adjacent a switch 1 so that it can be moved to actuate the switch operating member 6, and a cover 16 of water-impervious material covering the opening in the wall of the switch casing 1A which accommodates the operating member 6 and being movable to transmit the actuating movement of the actuator 7 to the switch operating member 6. Such an arrangement enables simple and relatively inexpensive switches 1, such as rocker switches, to be utilised on clothes and dish washing machines, the cover 16 effectively shielding the opening in the operative face of the switch casing 1A against the ingress of water. <IMAGE>

Description

SPECIFICATION Switch actuating arrangement This invention relates to actuating arrangements for electrical switches which are of the kind having a casing accommodating the switch contacts, and a pivotable operating member projecting from an opening in a wall of the casing for enabling the switch contacts to be opened and closed, and especially rocker switches, that is to say switches in which the operating members may have the form of a rocker pivotable between two positions in which each end of a member projects from its casing when the opposite end is depressed.

Such switches are not generally suitable for use in an environment where water is likely to be present, as if this should penetrate the opening in which the operating member is located, it could adversely affect the performance of the switch and possibly lead to a hazardous operation.

Accordingly alternative and specially designed forms of switches are commonly employed for clothes and dish washing machines, and other similar forms of equipment, in which operations involving the use of water are arranged to be carried out. However such switches are generally expensive, and often require complicated and expensive lin.kages to user operated controls.

According to the present invention an actuating arrangement for an electrical switch of the kind referred to comprises a separate manually operable actuator, movably supported adjacent the switch so that it can be moved to actuate a switch operating member for opening and closing the switch contacts, and a cover of waterimpervious material over at least the opening in the wall of the switch casing which accommodates the operating member, and located between the latter and the actuator, said cover being capable of movement to transmit the actuating movement of the actuator to the switch operating member.

Such an arrangement enables simple and relatively inexpensive forms of switches, such as rocker switches, as above described, to be utilised on clothes and dish washing machines, the cover effectively shielding the opening in the operative face of the switch casing, that is to say the face accommodating the switch operating member, against the ingress of water.

The actuator may be in the form of a manually operable rocker member which can be pivoted between two positions, the rocker member carrying a projection which, when the member is pivoted from one position to the other, results in the depression of the projecting end of the switch rocker to effect opening or closure of the switch contacts.

The projection may be in the form of a springloaded plunger which engages a recess in the cover, so that as the rocker member is moved from one position to the other it produces a corresponding sliding movement of the cover, this movement effecting the change in position of the switch rocker.

Conveniently the rear surface of the cover is arranged to engage and depress the projecting end of the switch rocker when the cover is moved from one position to the other by the operation of the actuator.

Where the switch casing is mounted within an opening in a planar region of a support, the edge of the cover preferably engages the surface of the support around the operative face of the switch casing and is capable of sliding movement relative to the support for enabling the movement of the actuator to be transmitted to the switch operating member.

The cover is preferably of a plastics material, and may for example consist of nylon lubricated with PTFE to facilitate the sliding movement of the cover, and also to provide for smooth engagement between the cover and the switch rocker.

The invention has particuiar application to clothes and dish washing machines and the invention includes within its scope machines of this kind incorporating a switch actuating arrangement in accordance with the invention.

One embodiment of the invention, as applied to a control console of a washing machine, will now be described by way of example with reference to the accompanying schematic drawings, in which Figure 1 is a plan view, in part section, of four rocker switches and accompanying actuating arrangements in accordance with the invention, Figure 2 is a part-sectional elevation of the assembly illustrated in Figure 1, Figure 3 is a sectional end elevation of one actuating arrangement with its associated rocker switch in one operating position, and Figure 4 is a similar view of the arrangement in its other operating position.

Referring to the drawings each rocker switch 1 comprises a body 1A enclosing the switch contacts and mounted in a respective aperture 2 in the planar base of a trough-shaped support bracket 3 forming part of the control console 4 of the washing machine (not shown), the switch bodies being self-supported within the apertures by means of spring retainers 5.

The opening and closure of the contacts of each of the switches is effected by means of a respective rocker 6 pivotally mounted in an opening 6A in the front face of the switch body 1A.

Operation of the switches 1 is controlled by a corresponding series of manually operable rocker buttons 7 each of which is pivotally mounted on a rod 9 which is supported at its end by two pivot supports 10, the rod forming a common mounting for the four buttons as shown. The pivot supports are secured to the support bracket 3 by means of screws 11.

Each rocker button 7 comprises a shroud portion 13 having a concave touch surface 1 3A and, within the shroud, an integrally moulded hollow boss 14 which projects centrally from the rear surface of the shroud and forms a housing for a plunger 15, spring loaded in the outward direction by a coil spring 1 8. The nose 1 5A of the plunger 1 5 is of rounded rectangular form shaped so as to fit snugly in a recess 1 SA in a switch cover 1 6 located between the rocker button 7 and the respective switch rocker 6.

The cover has a generally rectangular skirt 1 6B with an outwardly projecting flange 1 6C around its edge which is held in contact with the surface of the support bracket 3 around the front face of the switch body by the spring loaded plunger 1 5 of the rocker button 7.

The cover 1 6 is made from a moulded plastics material, such as nylon lubricated with PTFE, so as to provide ease of movement between the flange 1 6C and the support bracket 3. Moreover the lubricated surface of the cover 1 6 provides for smooth engagement between the cover and the switch rocker ô as will subsequently be described.

Operation of each switch 1 by its rocker button 7 from one position to the other (see Figure 4) is such that the switch cover 1 6 is correspondingly shifted and in so doing causes the rear or inner surface of the recessed part 1 6A of the cover to engage the projecting part of the switch rocker 6, thereby changing its position and thus opening or closing the switch contacts so as to electrically change the state of the circuit to which the switch is connected.

The cover 1 6 over the front face of the switch effectively prevents the ingress of liquid, and moreover as the rocker button is completely isolated from the switch by the cover 1 6 complete safety of operation is ensured. Moreover the arrangement provides a simple, cheap and reliable method of switch operation, the profile and the nature and movement of the rocker buttons providing ease of operation by the user, and the shape of the cover effectively transmitting this movement to the switch rockers.

However, although in the arrangement described, the manually operable members are provided by pivotally mounted rocker buttons, these could in some instances be replaced by members which are supported for sliding movement in a direction which produces the required movement of the cover 16 and hence of the switch rockers 6.

Moreover the covers themselves instead of being slidable relative to the switches may in some cases have their edges fixed, for example to the switch support or in some cases to the switch casing, and be formed of a flexible or otherwise deformable material which will transmit movement of the manually operable members to the respective switch rockers.

Claims (12)

1. An actuating arrangement for an electrical switch of the kind hereinbefore defined, comprising a separate manually operable actuator movably supported adjacent the switch so that it can be moved to actuate a switch operating member for opening and closing the switch contacts, and a cover of water-impervious material over at least the opening in the wall of the switch casing which accommodates the operating member, and located between the latter and the actuator, said cover being capable of movement to transmit the actuating movement of the actuator to the switch operating member.

2. An arrangement according to Claim 1 in which the switch is a rocker switch as hereinbefore defined.

3. An arrangement according to Claims 1 or 2 in which the actuator is in the form of a manually operable rocker member pivotable between two positions.

4. An arrangement according to any preceding claim in which the actuator carries a projection which, when the member is moved from said one position to the other, causes movement of the switch operating member and effects opening or closure of the switch contacts.

5. An arrangement according to Claim 4 in which the projection is in the form of a springloaded plunger arranged to engage a recess in the cover, so that as the rocker member is moved from said one position to the other it causes a corresponding movement of the cover, thus effecting movement of the switch operating member.

6. An arrangement according to any previous claim in which the rear surface of the cover is arranged to engage and depress the projecting end of the switch operating member when the cover is moved from one position to the other by operation of the actuator.

7. An arrangement according to any previous claim in which the switch casing is mounted within an opening in a planar region of a support and the edge of the cover is in contact with the surface of the support around the operative face of the switch casing and is capable of sliding movement relative to the support.

8. An arrangement according to any of Claims 1 to 6 in which the cover is fixed by its edges to the switch casing or to a support therefor and is composed of a flexible material.

9. An arrangement according to any preceding claim in which the cover is composed of a plastics material.

10. An arrangement according to Claim 9 in which the cover is composed of nylon lubricated with polytetrafluoroethylene.

11. An arrangement according to any preceding claim substantially as hereinbefore described with reference to Figures 1 to 4 of the accompanying drawings.

12. Any apparatus incorporating an arrangement subject to any preceding claim.