GB2325087A

GB2325087A - Electric switch

Info

Publication number: GB2325087A
Application number: GB9816520A
Authority: GB
Inventors: David Langman Cook
Original assignee: PDL Holdings Ltd
Current assignee: PDL Holdings Ltd
Priority date: 1994-09-02
Filing date: 1995-08-30
Publication date: 1998-11-11
Also published as: GB2325088A; GB2325088B; GB9816525D0; GB9816520D0

Abstract

An electric switch has a switch unit having fixed contacts (13, 14), a movable contact member (18) and an actuator (20). The actuator (20) is operable to move the movable contact member (18) to open or close an electric circuit between the contacts (13, 14). The switch unit is attached to a mounting plate (1). The electric switch also includes a switch rocker which is pivotally mounted in the mounting plate (1). The switch rocker incorporates a dependent control member. The control member is in line with the pivotal mounting of the switch rocker and is operatively engaged with the actuator (20) so that movement of the switch rocker causes the control member to move the actuator (20) to open or close the electric circuit between the contacts (13, 14). A waterproof diaphragm has a raised central section (28) which extends circumferentially about the control member. The central section is disposed at or adjacent the pivot line of the switch rocker.

Description

IMPROVEMENTS IN/OR RELATING TO ELECTRICAL SWITCHES This invention relates to electrical switches.

Electrical switches are required to operate in a variety of environments and to enable operation by a wide range of users. By way of an example, an environment may require the switch to be exposed to water or moisture requiring for safety a specially sealed switch. In many instances the consumers preference would be for a switch which provided a normal external appearance. An example of a special situation, would be a disabled or handicapped user requiring a larger switch rocker for the switch than would normally be provided.

An object of the present invention is to provide an electric switch which enables a switch unit to be associated with a mounting plate and switch rocker to accommodate different environmental or operational requirements.

Accordingly in one aspect the invention may broadly be said to consist in an electric switch comprising a mounting plate, a switch rocker pivotally mounted in said mounting plate said switch rocker incorporating a dependant control member, a switch module having fixed contacts a movable contact member and a actuator operable to move the movable contact member to open or close an electric circuit between the fixed contacts said switching unit being attached to the mounting plate with the switch rocker control member operatively engaged with the switch actuator so that movement of the switch rocker causes the control member to move the actuator to open or close an electric circuit between said fixed contacts.

In a further aspect the invention'may broadly be said to consist in an electric switch comprising a mounting plate, a switch rocker pivotally mounted in said mounting plate said switch rocker incorporating a dependant control member, waterproof diaphragm through which the control member of the switch rocker protrudes while maintaining a seal with said diaphragm, a switch module having fixed contacts and a movable contract member and a actuator operable to move the movable contact member to open or close an electric circuit between said fixed contact with the waterproof diaphragm providing a waterproof barrier between the switch and the mounting plate surrounding the switch rocker, and with the switch unit being mounted on the mounting plate with the switch rocker control member protruding through the waterproof diaphragm operatively engaging with said switch actuator so that movement of the switch rocker causes the control member to move the actuator to open or close an electric circuit between said fixed contacts.

In yet a further aspect the invention may broadly be said to consist in an electric switch comprising a mounting plate, a switch rocker aperture in said mounting plate, switch rocker pivotally mounted in said mounting plate to operate in said switch rocker aperture between two positions, said switch rocker being exposed from the front of the mounting plate for movement between the two positions and having dependant from the rear thereof a central transverse control member in line with the pivotal mounting for the switch rocker, a switch module mounted rearward of the mounting plate in operative engagement with the switch rocker control member, said switch module having a body fixed contacts located in said body of moveable contact member located in said switch body in the operative association with the fixed contacts, and actuator pivotally mounted in said switch body and operable to move the movable contact between positions to open and close the electric circuit between said fixed contacts.

In a still further aspect the invention may broadly be said to consist in an electric switch comprising a mounting plate having a switch rocker aperture therein, a switch rocker pivotally mounted in said mounting plate to operate in said switch rocker aperture between two positions, said switch rocker being exposed from the front of the mounting plate for movement between the two positions and having dependant from the rear thereof a central transverse control member in line with the pivotal mounting for the switch rocker, a switch module mounted at the rear of the mounting plate in operative engagement with the switch rocker control member, said switch module having a body fixed contacts located in said body a moveable contact member located in the switch body in the operative association with the fixed contacts, an actuator pivotally mounted in said switch body and operable to move the movable contact between positions to open and close the electric circuit between said fixed contacts and a waterproof diaphragm through which the central member of the switch rocker protrudes while maintaining a seal with the diaphragm and with the outer periphery of the diaphragm sealed about the switch rocker aperture to locate the switch unit beyond a waterproof diaphragm.

One preferred embodiment and modifications thereof are described with reference to the accompanying drawings in which: Figure 1 is a sectional view through an electric switch according to the present invention for use as a waterproof switch; Figure 2 is a section through a switched plug unit of modified construction also incorporating the waterproof switch; Figure 3 is an exploded view showing the various components in the electrical switch according to the present invention; Figure 4 is a plan view of the switch body; Figure 5 is a detail of one form of pivot connection in the mounting plate for the switch rocker; Figure 6 is a detail showing an alternate pivot connection for the switch rocker; Figure 7 is a detail of a larger switch rocker; Figure 8 is a rear view of the mounting plate with the switch unit attached and Figure 9 is a perspective view partly broken away of a waterproof switch unit having a detachable cover plate.

The electric switch according to the present invention may be applied in a number of different electrical fittings and an exemplary range of these has been included in the accompanying drawings. Figure 3 is an exploded view of the components and the present invention will be described with initial reference to figure 3 but the drawing reference numbers for the appropriate components will also be used on the other figures.

The switch has a mounting plate 1 in which is formed an aperture 2 to receive a switch rocker 3. The switch rocker 3 is pivotally mounted in the mounting plate 1. To achieve this pivotal mounting protuberances 4 project centrally from each side of the rocker 3, with the protuberances having a V recess in the upper surface. The protuberances engage a seat 5 having a complimentary V pivot 6 at the base of an open recess 7 as shown in greater detail in figure 5.

Alternatively the pivot 6 may be located in a closed recess 8 with the protuberances 4 formed to engage with a force fit into the recesses 8 thus retaining the switch rocker 3 in engagement with the mounting plate 1 once fitted in place.

Movement of the switch rocker is limited by stops 9 engaging with part of the mounting plate so that the rocker moves between two defined positions for the switching action.

Dependant centrally from the undersurface of the rocker is a transverse control member 10 substantially in line with the pivot projections 4. The member 10 is shaped to engage with and operate an actuator of a switch unit as will be described in greater detail here below.

The size of the switch rocker 3 can be varied For normal use a conventional switch rocker size would adopted but for special purposes, for example, if the switch was to be used in an environment requiring easier operation, for example, for disabled people, a larger switch rocker could be incorporated in the mounting plate and an example of the larger switch rocker is illustrated as 3a in figure 7.

The switch rocker is designed to operate a switch unit 11. The switch unit has a switch body 12 in which are located two fixed contacts 13 and 14 with terminals 15 and 16 to allow electrical connection. A central transverse pivot 17 is also provided on which is pivotally supported a movable contact member 18. The moveable contact member has central projections 19 from either side which engage within locating recess 20 in the switch base. The moveable contact 18 is thus pivotally mounted in the switch base and can move between two positions to effect the switching action.

An actuator 20 has a spring loaded plunger 21 which engages the top surface of the moveable contact 18. The actuator 20 has projections 22 from either side thereof that engage within apertures 23 in the side of the switch body to provide a pivotal mounting.

On the top surface of the actuator 20 is a member 23 locating a central transverse recess 24 which in use is engaged by the end of the control member 10 protruding from the switch rocker 3.

The switch unit 11 has a mount 25 in which the switch unit engages. The mount 25 is screwed to the mounting plate with screws 25a so that the switch unit is held in place with the control member of the switch rocker operatively engaged with the recess 24 of the actuator 20. The body of the switch unit 11 has retaining arms 25b so that when the body is pressed into mount 25 the arms will retain the body in place.

Where the switch is used in an environment requiring waterproofing a suitable waterproof membrane 26 is located between the switch mounting plate 1 and the switch unit 11. The waterproof diaphragm is shaped to ensure that there is an adequate seal about the control member 10 which protrudes through the diaphragm and with the periphery with the diaphragm sealed in engagement with the mounting plate. It is preferable to have a shaped diaphragm having a peripheral rib 27 a raised central section 28 with a central transverse slot 29 to engage about the control member 10. The configuration of the diaphragm is such that the slot 29 is arranged so that in the normal position the diaphragm will engage the control member 10 of the rocker switch at or adjacent the pivot line of the rocker. This can be seen in figure 1. In this way movement of the switch rocker causes minimal movement of the diaphragm thus assisting in preserving the life of the diaphragm and ensuring a long operating life of the waterproof switch. The mount 25 is arranged to ensure that there is a good peripheral seal of the diaphragm when the switch is assembled as is shown in figure 1.

The embodiment illustrated in figure 2 is a switched plug unit 30 the switch body 12a has essentially the same components as were described above, but the switch unit is mounted directly in the mounting plate la and an escutcheon member 31 in the mounting plate which defined the aperture for the switch rocker holds the waterproof diaphragm 26a in position.

A similar configuration is illustrated in figure 9 where a switch unit made in the same style is illustrated. The switch has a mounting plate lb over which is fitted in use a removable cover 32. The escutcheon 31 and the diaphragm 26a remain the same as illustrated in figure 2.

The present invention provides a switch which used with the waterproof diaphragm allows the switch to pass all of the Australian, British and New Zealand standard specifications required for a waterproof switch.

It will be apparent from the foregoing that the actuator mechanism can be designed to suit any particular requirement. For example, the same operating arrangement could be preserved but the actuator significantly enlarged to provide the user with a large actuator surface. In this instance it would not be necessary to provide the sealing as is required for a waterproof embodiment of the present invention.

The present invention allows a conventional switch module to be incorporated in a mounting plate that can either assume the appearance of a standard switch or be modified so that the switch rocker surface is of any desired size.

Claims

CLAMS:

1. An electric switch including: a mounting plate; a switch rocker pivotally mounted in said mounting p]ate, said switch rocker incorporating a dependent control member in line with the pivotal mounting of the switch rocker; a switch unit having fixed contacts, a movable contact member and an actuator operable to move the movable contact member to open or close an electric circuit between the contacts, the control member being operatively engaged with the actuator so that movement of the switch rocker causes ie control member to move the actuator to open or close an electric circuit between said fixed contacts; a waterproof diaphragm fixed in scaling engagement along a peripheral portion ofthe switch unit surrounding the actuator, wherein a raised central section ofthe diaphragm extends circumferentially about the control member, the raised central section being disposed at or adjacent the pivot line of the switch rocker.

2. The electric switch as claimed in claim I wherein the diaphragm is also fixed in sealing engagement with the mounting plate.

3 The electric switch as claimed in claim 1 or claim 2 wherein said raised central section of the diaphragm is of reduced thickness.