GB2285885A

GB2285885A - An electrical switch

Info

Publication number: GB2285885A
Application number: GB9400526A
Authority: GB
Inventors: Terence William Thomas
Original assignee: MK Electric Ltd
Current assignee: Novar ED&S Ltd
Priority date: 1994-01-13
Filing date: 1994-01-13
Publication date: 1995-07-26
Anticipated expiration: 2014-01-13
Also published as: GB9400526D0; GB2285885B

Abstract

An electrical switch comprises a movably mounted, switch actuator (2), a resilient contact (6) mounted on the actuator (2) and two fixed contacts (18, 19). The actuator is arranged to move the resilient contact so as to make or break an electrical circuit between the fixed contacts. The actuator may pivot, rotate or slide between the contacts. <IMAGE>

Description

AN ELECTRICAL SWITCH The present invention relates to an electrical switch.

Electrical switches for domestic mains power or lighting supplies come in many forms. Commonly the switch comprises a rocker, a fixed and a moving contact, the rocker having a movable plunger and a coil spring acting on the plunger. The fitting of the coil spring during assembly is troublesome and there are necessarily several parts for the switch.

An electrical switch according to the invention comprises a movably mounted switch actuator, a resilient contact mounted on the actuator and two fixed contacts, the actuator being arranged to move the resilient contact to a position so as to make or break an electrical circuit between the fixed contacts.

The actuator may be a rocker arranged to pivot between a made or broken position of the switch or a rotational member.

Preferably the resilient contact has a substantially U shaped contacting portion guided by a protrusion of the actuator, the protrusion fitting within the U shaped portion.

In a first embodiment where the actuator is a pivotally mounted rocker the resilient contact is formed as a metal strip having arm portions extending outwardly and at an angle from the U shaped portion so as to assume the shape of a T, the arm portions acting to bias the contacting portion away from the pivotal mounting of the rocker onto the fixed contacts.

In a second embodiment where the actuator is a rotationally mounted rotational member the resilient contact is formed as a metal strip with arms extending from the U shaped contacting portion to a mounting on the rotational member, the arms each having a U shaped resiliently deformable portion between the contacting portion and the mounting, the resiliently deformable portion acting to bias the contacting portion away from the rotational mounting of the rotational member onto the fixed contacts.

In a third embodiment the actuator is slidably mounted and the resilient contact is substantially the same as that of the first embodiment.

In a fourth embodiment the actuator is pivotally mounted and the resilient contact is substantially the same as that in the second embodiment.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a cross sectional side view of a first embodiment of a switch according to the invention in an "on" or contacting condition with initial pressure tending to switch to "off".

Figure 2 is a cross sectional side view of the switch of Fig. 1 as it switches off.

Figure 3 is a cross sectional side view of the switch of Fig. 1 in the fully "on" condition.

Figure 4 is a cross sectional side view of the switch of Fig. 1 in the fully "off" condition.

Figure 5 is an underside view of the rocker and resilient contact of the switch of Fig. 1 seen from X in Fig. 2, Figure 6 is a cross sectional side view of a second embodiment of a switch according to the invention.

Figure 7 is a cross sectional side view of a third embodiment of a switch according to the invention, and Figure 8 is a cross sectional side view of a fourth embodiment of a switch according to the invention.

With the intention of providing a very simple switch Figures 1 to 5 show a first embodiment of an electrical switch according to the invention in which a switch actuator is formed as a rocker 2 is pivotally mounted about pivots 4 which can be a single pin or protruding mouldings.

A resilient contact 6 made of resilient brass, or other metal strip is formed as a "T" shape with a lower "U" shaped contacting portion 8 and upper arm portions 10 extending outwardly at an angle of about 700 before assembly. The arm portions 10 each fit into a recess 12 in rocker 2 either side of the pivot axis 4. Extending downwardly from the rocker 2 at right angles to the upper surface 14 of the rocker 2 is a protrusion 16 which guides the "U" shaped contacting portion 8. The arm portions 10 act against the rocker 2 to urge the "U" shaped portion 8 outwardly and downwardly against fixed electrical contacts 18 and 19 so as to make an electrical contact between them in the on position as shown in Fig. 3.

In order to switch the switch to off the rocker is pressed as shown in Fig. 1. Portion 8 then slides up guide protrusion 16 into the position shown in Fig. 2. Finally, as the protrusion 16 moves clockwise portion 8 springs downwards to locate between contact 18 and an insulated stop 20.

A second embodiment as shown in Fig. 6 comprises an actuator formed as a rotational member 22 secured to or part of a knob 23 rotatably mounted about an axis 24 which can be a pin or protruding mouldings. A resilient contact 26 made of resilient brass strip is formed with a "U" shaped contacting portion 28 and upper arm portion 29 extending to a mounting formed as mounting slots 30 in the member 22 either side of a protrusion 36 which guides the contacting portion 28. The arms each have a U shaped resiliently deformable portion 32 between the contacting portion and the mounting. The resiliently deformable portions act to bias the contacting portion outwardly and downwardly against fixed electrical contacts 38 and 39, 38' and 39' and so on, mounted around a curved block 40.

A third embodiment is shown in Fig. 7 which comprises an actuator formed as a slide 42 slidably mounted in a slot 44.

A resilient "T" shaped contact 6 is identical to the contact of the first embodiment and is referenced the same. Contact 6 fits into recesses 52 either side of protrusion 56 in the same way as contact 6 fits into recesses 10 of the first embodiment. The arm portions 10 act against the slide 42 to urge the "U" shaped portion 8 outwardly and downwardly against fixed electrical contacts 58, 59 and 60 making an electrical contact between fixed contacts 58 and 59 or 58 and 60.

A fourth embodiment is shown in Fig. 8 which comprises an actuator formed as a toggle member 62 pivotally mounted about axis 64. A resilient contact 26 is identical to the contact of the second embodiments and is referenced the same. The contact arms 29 fit into mounting slots 70 in member 62 and either side of protrusion 76 in the same way as the second embodiment. The resiling portions 32 act to bias to contacting portion outwardly and downwardly against fixed electrical contacts 78 and 79 in the "on" position. With the toggle member in the position shown in Fig. 8 the contact 26 rests between contact 78 and insulated stop 80.

Contact portions 8 and 28 are normally silver plated.

Claims

1. An electrical switch comprising a movably mounted switch actuator, a resilient contact mounted on the actuator and two fixed contacts, the actuator being arranged to move the resilient contact to a position so as to make or break an electrical circuit between the fixed contacts.

2. A switch as claimed in claim 1 wherein the resilient contact is arranged to move toward the actuator during the movement to or from the fixed contacts and to move away from the actuator into the made position between the fixed contacts.

3. A switch as claimed in claim 1 or 2 wherein the actuator has a protrusion and the resilient contact has a substantially U shaped contacting portion guided by the protrusion of the actuator, the protrusion fitting within the U shaped portion.

4. A switch as claimed in any one of claims 1 to 3 wherein the actuator is a rocker arranged to pivot between the made or broken position of the switch.

5. A switch as claimed in claim 4 wherein the resilient contact is framed as a metal strip having arm portions extending outwardly and at an angle from a central contacting portion so as to assume a "T" shape, the arm portions acting to bias the contacting portions away from the pivotal mounting of the rocker onto the fixed contacts.

6. A switch as claimed in claim 3 wherein the actuator is an at least part rotationally mounted member, the resilient contact being formed as a metal strip with arms extending from the U shaped contacting portion to a mounting on the at least partly rotational member, the arms having a "L", "U' or "V" shaped resiliently deformable portion extending outwardly from the protrusion of the actuator.

7. A switch as claimed in claim 6 wherein the actuator is fully rotational.

8. An electrical switch substantially as described with reference to Figures 1 to 5 of the accompanying drawings.

9. An electrical switch substantially as described with reference to Figure 8 of the accompanying drawings.

9. An electrical switch substantially as described with reference to Figure 6 of the accompanying drawings.

10. An electrical switch substantially as described with reference to Figure 7 of the accompanying drawings.

11. An electrical switch substantially as described with reference to Figure 8 of the accompanying drawings.

Amendments to the claims have been filed as follows CLAIMS 1. An electrical switch comprising a movably mounted switch actuator, a resilient contact mounted on the actuator and two fixed contacts, the actuator being arranged to move the resilient contact to a position so as to make or break an electrical circuit between the fixed contacts wherein the actuator has a substantially U-shaped contacting portion guided by a protrusion of the actuator fitting within the U-shaped portion and wherein the resilient contact is arranged to move toward the actuator during a movement to or from the fixed contacts and to move away from the actuator into the made position between the fixed contacts.

2. A switch as claimed in claim 1 wherein the actuator LS a rocker arranged to pivot between the made or broken position of the switch.

3. A switch as claimed in claim 2 wherein the resilient contact is framed as a metal strip having arm portions extending outwardly and at an angle from a central contacting portion so as to assume a "T" shape, the arm portions acting to bias the contacting portions away from the pivotal mounting of the rocker onto the fixed contacts.

4. A switch as claimed in claim 1 wherein the actuator is an at least part rotationally mounted member, the resilient contact being formed as a metal strip with arms extending from the U shaped contacting portion to a mounting on the at least partly rotational member, the arms having a "L", "U" or "V" shaped resiliently deformable portion extending outwardly from the protrusion of the actuator.

5. A switch as claimed in claim 4 wherein the actuator is fully rotational.

6. An electrical switch substantially as described with reference to Figures 1 to 5 of the accompanying drawings.

7. An electrical switch substantially as described with reference to Figure 6 of the accompanying drawings.

8. An electrical switch substantially as described with reference to Figure 7 of the accompanying drawings.