GB2253517A

GB2253517A - Electrical switch arrangement

Info

Publication number: GB2253517A
Application number: GB9102948A
Authority: GB
Inventors: Peter Nelson Stenning; Charles Dominic Courtney Beer
Original assignee: Otehall Ltd; Otehall Switches Ltd
Current assignee: Otehall Ltd; Otehall Switches Ltd
Priority date: 1991-02-12
Filing date: 1991-02-12
Publication date: 1992-09-09
Also published as: GB9102948D0

Abstract

An electrical switch arrangement comprises a miniature two-position switch 1 having an actuator 2 projecting from the switch casing. The switch 1 is carried by a support 4 which includes a hollow spigot 10 for mounting the switch through an opening in a panel or the like. A push-push mechanism 11 is contained within the spigot 10, and has a manually-operable member 12 extending outwardly from the spigot 10 for actuating the switch 1 by cooperation with the actuator 2. <IMAGE>

Description

ELECTRICAL SWITCH ARRANGEMENT The present invention relates to an electrical switch arrangement and more particularly to such arrangements including miniature electrical switches.

Miniature electrical switches generally comprise one or more sets of electrical contacts contained within a casing which are actuated by an actuator projecting out of the casing. The casing may be supported on a bracket for mounting on a panel or the like, and the actuator may be operated to actuate the switch by means of a manuallyoperable plunger, press-button, lever or rocker.

It is an object of the present invention to provide a compact construction of an electrical switch arrangement, which is particularly but not exclusively suitable for use with miniature electrical switches.

According to one aspect of the present invention, there is provided an electrical switch arrangement comprising a switch mechanism enclosed within a casing and having at least two positions of operation to which it may be actuated by means of an actuator projecting externally of the casing, said casing being carried by a support having a hollow spigot by means of which the support may be mounted on a panel or the like with the spigot extending through a hole in said panel or the like and secured thereto, and a push-push mechanism including a manually-operable member to operate the actuator to actuate the switch mechanism, the push-push mechanism being contained within the hollow spigot with the manually-operable member extending outwardly from said spigot.

According to another aspect of the invention, there is provided an electrical switch arrangement comprising a miniature two position switch mechanism enclosed within a casing and having an actuator for actuating said switch mechanism projecting externally of the casing, said casing being carried by a support having a hollow spigot which is devised to extend through a hole in a panel orqthe like and be secured thereto in order to mount said support on said panel or the like, and a push-push mechanism contained within said hollow spigot and having a manually-operable member extending outwardly from said spigot for operating the actuator to cause the switch mechanism to assume either of its ;two positions alternately one after the other.

Advantageously, the push-push mechanism is of the rotating-sleeve push-action type, in which successive push actions of the manually-operable member cause the actuator to be alternately depressed towards the switching mechanism and released to return to its original position.

In a preferred embodiment, the push-push mechanism includes a rotatable sleeve which is axially displaceable within a tubular member in a reciprocating manner against the bias of a spring. The sleeve is preferably provided with projections which alternately engage with and engage between guides provided on the inner surface of the tubular member as the sleeve is rotated by successive push-actions of the manually-operable member.

The push-push mechanism may be provided with a lost-motion overtravel facility enabling the manuallyoperable member to be pushed further after the actuator actuates the switch mechanism.

The hollow spigot is preferably provided on its outer surface with screw-threading to receive a fastening nut, for securing the spigot in the hole of the panel or the like on which the support may be mounted. The support and hollow spigot may be integrally formed from a moulded plastics material.

The invention will now be further described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a perspective, part sectional view of an electrical switch arrangement in accordance with one embodiment of the present invention; Figure 2 shows a perspective view of the support of the arrangement shown in Figure 1; and Figures 3a to 3e show respective component parts of the push-push mechanism of the arrangement shown in Figure 1.

Referring now to the drawings, an electrical switch arrangement comprises a casing 1 within which a two position switch mechanism (not shown) consisting of one or more sets of electrical contacts is enclosed. An actuator 2 for actuating the switch mechanism projects externally from one side of the casing and a plurality of electrical connecting pins 3 also extend externally from the casing. The casing 1 is carried by a support bracket 4 which has two pegs 5,6 projecting from a side wall 7 thereof, which are inserted into respective through-holes 7,8 of the casing 1 in order to mount the casing on the bracket.

Extending from a wall 9 of the bracket 4, arranged at right angles to the wall 7, is a hollow spigot 10 which is screwthreaded on its outer surface so that the spigot can be secured within a hole of a panel or the like by means of a clamping nut (not shown) threaded onto the spigot.

A push-push mechanism 11 of the type having a rotating-sleeve, push-button action, is contained within the hollow spigot 10 and includes a manually-operable plunger 12 which extends outwardly from the spigot. The push-push mechanism also includes a rotatable sleeve 13 and a spring 14 which are both securely mounted on a rod 15 connected at one end to a plate 16. The rod 15, retaining the sleeve and the spring, extends into a tubular member 17 located within the hollow spigot, and the plate 16 engages with the switch actuator 2 located below the hollow spigot.

The tubular member 17 also serves as a guide for the plunger 12. The rotatable sleeve 13 is provided on its outer surface with projections 18 equally spaced around its periphery which engage with teeth 19 provided around the inner end of the plunger 12 and which also engage with and between guides 20 spaced around the inner surface of the tubular member 17.

When the manually-operable plunger 12 is depressed, the sleeve, and thus the rod and plate, are displaced axially with respect to the tubular member such that the actuator 2 is depressed towards the casing 1 to cause the contacts within the casing to assume a first operating position. At the same time, the sleeve projections 18 are engaged by the teeth 19 until they reach the ends of the guides 20. At this point, the projections i8 will ride over the teeth 19 and cause the sleeve to rotate such that the projections 18 engage with the guides 20. Upon subsequent release of the plunger, the mechanism maintains the actuator in its depressed position. When the plunger is depressed again, the sleeve rotates and the sleeve projections engage between the guides 20.This action displaces the sleeve, and thus the rod and plate, in the direction away from the actuator under the action of the spring 14, thereby moving the plate away from the casing 1, which releases the actuator 2 and causes the contacts within the casing to assume a second operating position. Upon release of the plunger 12, the mechanism causes the actuator to maintain the contacts in their second operating position. In this manner, successive push-actions of the plunger cause the switch mechanism to alternate between its two operating positions.

The present invention thus provides an electrical switch arrangement, particularly suitable for embodying miniature two-position switches, wherein the push-push mechanism is contained within the mounting spigot in order to provide a neat and compact design. Furthermore, the components part of the switch arrangement can be manufactured cheaply and assembled quickly and easily.

The component parts of the push-push mechanism, except for the spring, may be made from plastics material by injection moulding or any other suitable technique.

Preferably also, the support bracket is made from moulded plastics material having the spigot integrally moulded therewith.

Whilst a particular embodiment has been described, it will be apparent that various modifications may be made within the scope of the invention.

For example, the plunger may be provided with a lost-motion overtravel facility to enable it to be pressed further into the spigot after the actuator actuates the switch mechanism.

The screw-threading of the spigot is preferably standard, but could alternatively be another form of screw-threading or any other means for securing the spigot into a hole in a panel or the like.

Moreover, there may be any appropriate number of projections equally spaced around the rotatable sleeve and/or guides equally spaced around the inner surface of the tubular member. In a preferred arrangement, there are however four sleeve projections and two or possibly four guides.

Additionally, the plunger of the push-push mechanism could be used to operate more than one switch arrangement, for example two switches located side-by-side.

Although in the described embodiment, the manuallyoperable member is a plunger, any other suitable actuator, such as a press-button, lever or rocker, may be used instead.

Claims

1. An electrical switch arrangement comprising a switch mechanism enclosed within a casing and having at least two positions of operation to which it may be actuated by means of an actuator projecting externally of the casing, said casing being carried by a support having a hollow spigot by means of which the support may be mounted on a panel or the like with the spigot extending through a hole in said panel or the like and secured thereto, and a push-push mechanism including a manually-operable member to operate the actuator to actuate the switch mechanism, the push-push mechanism being contained within the hollow spigot with the manually-operable member extending outwardly from said spigot.

2. An electrical switch arrangement comprising a miniature two position switch mechanism enclosed within a casing and having an actuator for actuating said switch mechanism projecting externally of the casing, said casing being carried by a support having a hollow spigot which is devised to extend through a hole in a panel or the like and be secured thereto in order to mount said support on said panel or the like, and a push-push mechanism contained within said hollow spigot and having a manually-operable member extending outwardly from said spigot for operating the actuator to cause the switch mechanism to assume either of its two positions alternately one after the other.

3. An electrical switch arrangement as claimed in claim 1 or 2, wherein the push-push mechanism is of the rotating-sleeve push-action type, in which successive push actions of the manually-operable member cause the actuator to be alternately depressed towards the switch mechanism and released to return to its original position.

4. An electrical switch arrangement as claimed in claim 1, 2 or 3, wherein the push-push mechanism includes a rotatable sleeve which is axially displaceable within a tubular member in a reciprocating manner against the bias of a spring.

5. An electrical switch arrangement as claimed in claim 4, wherein the sleeve is provided with projections which alternately engage with and engage between guides provided on the inner surface of the tubular member as the sleeve is rotated by successive push-actions of the manually-operable member.

6. An electrical switch arrangement as claimed in any preceding claim, wherein the push-push mechanism is provided with a lost-motion overtravel facility enabling the manually-operable member to be pushed further after the actuator actuates the switch mechanism.

7. An electrical switch arrangement as claimed in any preceding claim, wherein the hollow spigot is provided on its outer surface with screw-threading to receive a fastening nut, for securing the spigot in the hole of the panel or the like on which the support may be mounted.

8. An electrical switch arrangement as claimed in any preceding claim, wherein the support and hollow spigot are integrally formed from a moulded plastics material.

9. An electrical switch arrangement as claimed in any preceding claim, wherein the support comprises a first support surface from which the spigot extends, and a second support surface disposed generally perpendicular to the first support surface the second support surface including means for mounting the switch.

10. An electrical switch arrangement as claimed in claim 9, wherein the means for mounting the switch includes at least one peg adapted to extend through an aperture in the switch casing.

11. An electrical switch arrangement substantially as described herein, with reference to the accompanying drawings.