GB2287127A

GB2287127A - Electrical rocker switch

Info

Publication number: GB2287127A
Application number: GB9403854A
Authority: GB
Inventors: Raymond Chu
Original assignee: Defond Manufacturing Ltd
Current assignee: Defond Manufacturing Ltd
Priority date: 1994-03-01
Filing date: 1994-03-01
Publication date: 1995-09-06
Also published as: GB9403854D0

Abstract

An electrical rocker switch (10) comprises a body (11), et least first and second switch terminals (13 & 14) extending from inside to out of the body (11), a first electrical contact (15) provided at the inner end (13A) of the first switch terminal (13), a second, resiliently biassed electrical contact (16) provided at the inner end (14A) of the second switch terminal (14), and a switch operating rocker (17) held by the body (11) for rocking motion between first and second rocking positions. In the first rocking position, the second electrical contact (16) is in electrical contact with the first electrical contact (15). In the second rocking position, the second electrical contact (16) is out of electrical contact with the first electrical contact (15). The rocking motion of the rocker (17) results in deflection of the second electrical contact (16). The second electrical contact (16) is configured in the form of a cantilever. <IMAGE>

Description

ELECTRICAL ROCKER SWITCH The present invention relates to an electrical rocker switch which has improved performance.

According to the invention, there is provided an electrical rocker switch which comprises a body, at least first and second switch terminals extending from inside to out of the body, a first electrical contact provided at the inner end of the first switch terminal, a second, resiliently biassed electrical contact provided at the inner end of the second switch terminal, said second electrical contact being in the form of a cantilever, and a switch operating rocker held by the body for rocking motion, thereby resulting in deflection of the second electrical contact, between a first rocking position in which the second electrical contact is in electrical contact with the first electrical contact and a second rocking position in which the second electrical contact is out of electrical contact with the first electrical contact.

Preferably, the rear end of the second electrical contact is bent in order to enhance the resilient bias of the second electrical contact.

In a specific arrangement, the second electrical contact is normally biassed into electrical contact with the first electrical contact.

It is preferred that the first electrical contact is fixed.

The electrical rocker switch may further comprise a switching member disposed between the rocker and the second electrical contact for movement by the rocker, thereby resulting in said deflection of the second electrical contact, wherein the switching member is supported for pivotal movement between two positions corresponding to the first and second rocking positions of the rocker but in opposite direction.

In a specific construction, the body has on opposite sides thereof a pair of aligned fulcrums, and the switching member has two aligned opposite side protrusions resting on the corresponding fulcrums.

Preferably, the switching member has on opposite ends thereof a pair of stops for restricting the rocking motion of the rocker, thereby positively defining the rocking positions of the rocker.

In a preferred embodiment, the rocker has an internal leg for effecting switching operation.

More preferably, the rocker leg is resiliently extensible.

The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional side view of an embodiment of an electrical rocker switch in accordance with the invention, in a switched-on condition; Figure 2 is a cross-sectional side view of the rocker switch of Figure 1, in a switched-off condition; Figure 3 is a cross-sectional side view of the rocker switch of Figure 1, taken along an off-axis cutting plane; and Figure 4 is a cross-sectional end view of the rocker switch of Figure 3.

Referring to the drawings, there is shown an electrical rocker switch 10 embodying the invention, which rocker switch 10 comprises a cuboidal plastics body 11 having a base 12 through which a pair of (at least two) first and second switch terminals 13 and 14 extending from inside to out of the body 11. A fixed electrical contact 15 is connected to an inner end 13A of the first switch terminal 13, extending at right angles thereto. Inner end 14A of the second switch terminal 14 extends at right angles to form a movable electrical contact 16 which overlaps at its free end with and underneath the fixed contact 15. The movable contact 16 is resiliently deformable and is configured in the form of a cantilever capable of deflecting up and down. By virtue of its resilience, the movable contact 16 is resiliently biassed to deflect upwards into electrical contact with the fixed contact 15.

At the junction with the switch terminal inner end 14A, the rear end of the movable contact 16 is bent into an upward semi-circular section 16A, with a reduced width, for enhancing resilience.

The rocker switch 10 further includes a switch operating rocker 17 pivotably held by a pair of aligned holes 9 formed in opposite side walls of the switch body 11 for rocking motion, and a pivotable switching member 20 disposed between the rocker 17 and the movable contact 16.

The rocker 17 has internally a depending tubular post 17A, in which there are slidably located a partially exposed plunger 18 and trapped behind the plunger 18 a compression coil spring 19, thereby form a leg assembly. The spring 19 resiliently urges the plunger 18 outwards against the top side of the switching member 20.

Opposite side walls of the switch body 11 has a pair of aligned fulcrums 21 which are provided by corresponding upwardly pointing triangular steps 21' formed integrally on the inner sides of the body side walls, as best shown in Figure 4. The switching member 20 has on opposite sides thereof a pair of aligned side protrusions 22, each of which has an underside recess 23 for engaging the apex of the respective fulcrum 21, whereby the switching member 20 rests pivotably on the fulcrums 21. The switching member 20 has a downturned front end 20A and an upwardly slightly bent rear end 20B. Two upstanding integral stops 24A and 24B are formed on the top side of the switching member 20, the first stop 24A being at the front end 20A and the second stop 24B being near the rear end 20B. The switch body 11 has internally a relatively taller stopper 12A, upstanding from the base 12, for the switch member rear end 20B to engage atop, and a relatively shorter stopper 12B, also upstanding from the base 12, for abutting the underside of the movable contact 16.

In the assembled switch 10, the switching member 20 is pivoted on the fulcrums 21, overlying the movable contact 16, and the tip of the plunger 18 bears from above against the switching member 20 in the region between the two stops 24A and 24B. Under the action of the rocker spring 19, the rocker plunger 18 will pivot the switching member 20 in either clockwise or anti-clockwise direction into the following two stable conditions.

Referring to Figure 1, the rocker plunger 18 swings anticlockwise, and the switching member 20 stops being pivoted clockwise by the plunger 18 when its rear end 20B hits the taller stopper 12A with the tip of the plunger 18 bearing against the stop 21B, In this position, the switching member front end 20A is lifted off the movable contact 16, thereby permitting the movable contact 16 to come into electrical contact with the fixed contact 15. The rocker switch 10 is then in a stable switched-on condition.

Referring to Figure 2, the rocker plunger 18 swings clockwise to pivot the switching member 20 anti-clockwise.

During this movement, the switching member front end 20A engages and hence pushes the movable contact 16 downwards off the fixed contact 15, until the movable contact 16 hits the shorter stopper 12B with the tip of the plunger 18 bearing against the stop 24A. The rocker switch 10 is then in a stable switched-off condition.

It is to be appreciated that the stoppers 12A and 12B are optional and may be replaced by some other parts of the switch body 11 engaging, for example, the main knob body of the rocker 17 as shown by X and F of Figures 1 and 2. The movable contact 16 of this particular rocker switch 10 is resiliently biassed into electrical contact with the fixed contact 15, but may equally well be biassed off the fixed contact 15.

The integral formation, or alternatively direct rigid connection, of the movable contact 16 with the switch terminal 14 ensures good electrical conduction. With the use of the bend 16A, whether circular or not and with or without a reduced width, to enhance flexibility, the switch contact 16 may be made thicker in order to improve electrical conductivity without sacrificing flexibility.

The switch contact 15 may not be fixed.

During switching operation, the switching member 20 is subject to resilient biassing action not only by the rocker spring 19 from above but also by the movable contact 16 springing upwards. This arrangement is designed to provide a good, well-defined and positive physical switching feeling.

The invention has been given by way of example only, and various other modifications of and/or alterations to the described embodiment may be made by persons skilled in the art without departing from the scope of the invention as specified in the appended claims.

Claims

CLAIM

1. An electrical rocker switch comprising a body, at least first and second switch terminals extending from inside to out of the body, a first electrical contact provided at the inner end of the first switch terminal, a second, resiliently biassed electrical contact provided at the inner end of the second switch terminal, said second electrical contact being in the form of a cantilever, and a switch operating rocker held by the body for rocking motion, thereby resulting in deflection of the second electrical contact, between a first rocking position in which the second electrical contact is in electrical contact with the first electrical contact and a second rocking position in which the second electrical contact is out of electrical contact with the first electrical contact.

2. An electrical rocker switch as claimed in claim 1, wherein the rear end of the second electrical contact is bent in order to enhance the resilient bias of the second electrical contact.

3. An electrical rocker switch as claimed in claim 1 or claim 2, wherein the second electrical contact is normally biassed into electrical contact with the first electrical contact.

4. An electrical rocker switch as claimed in any one of claims 1 to 3, wherein the first electrical contact is fixed.

5. An electrical rocker switch as claimed in any one of the preceding claims, further comprising a switching member disposed between the rocker and the second electrical contact for movement by the rocker, thereby resulting in said deflection of the second electrical contact, wherein the switching member is supported for pivotal movement between two positions corresponding to the first and second rocking positions of the rocker but in opposite direction.

6. An electrical rocker switch as claimed in claim 5, wherein the body has on opposite sides thereof a pair of aligned fulcrums, and the switching member has two aligned opposite side protrusions resting on the corresponding fulcrums.

7. An electrical rocker switch as claimed in claim 5 or claim 6, wherein the switching member has on opposite ends thereof a pair of stops for restricting the rocking motion of the rocker, thereby positively defining the rocking positions of the rocker.

8. An electrical rocker switch as claimed in any one of the preceding claims, wherein the rocker has an internal leg for effecting switching operation.

9. An electrical rocker switch as claimed in claim 8, wherein the rocker leg is resiliently extensible.

10. An electrical rocker switch substantially as hereinbefore described with reference to Figures 1 to 4 of the accompanying drawings.