GB2161024A

GB2161024A - Improvements relating to switches for electric lighting devices

Info

Publication number: GB2161024A
Application number: GB08516114A
Authority: GB
Inventors: Yin Hui
Original assignee: Sonca Ind Ltd
Current assignee: Sonca Ind Ltd
Priority date: 1984-06-29
Filing date: 1985-06-26
Publication date: 1986-01-02
Also published as: GB8516114D0; GB8416615D0; GB2161024B

Abstract

An electric lighting device comprises a casing 10 housing a bulb holder 13 and a dry cell compartment. Conductors 16,21 are provided for connecting the dry cells 11 in circuit with the bulb holder and incorporate a switch 19 having a pivoted contact member within the casing 10 and a switch actuating member 30 outside the casing. The contact member is ferrous and the actuating member 30 carries a magnet 32 and is movable into a first location in which the contact member is caused to rock about a pivot intermediate its ends into a first position completing the circuit and into a second location in which the contact member is caused to rock into a second position interrupting the circuit. No part of the switch physically extends through the casing. <IMAGE>

Description

SPECIFICATION Improvements relating to electric lighting devices This invention relates to electric lighting devices for example lanterns and flashlights.

According to this invention there is provided an electric lighting device comprising a casing which houses a bulb holder and which incorporates a compartment for one or more dry cells, and contact means for connecting the cell or cells in circuit with the bulb holder which means includes a switch disposed within the casing, said switch comprising a contact member pivoted intermediate its ends for rocking movement into a first position in which the contact member completes said circuit and into a second position in which the contact member interrupts said circuit, and a switch actuating member carrying a magnet and mounted on the outside of the casing for guided movement selectively into each of two locations in one of which the magnet causes the contact member to rock into said first position and in the other of which causes the contact member to rock into said second position.

It is a preferred feature of the invention that the contact member has a contact point at one end and a contact point at its pivot for completing said circuit, which contacts are electrically connected together.

It is another preferred feature that the switch is mounted on a carrier attached to the casing and the contact member comprises a ferrous member pivotally mounted on the carrier for said rocking movement one end of said ferrous member being attracted by the magnet when the switch actuating member is in its first position and the other end of said ferrous member being attracted by the magnet when the switch actuating member is in its second position thus producing the rocking movement of the contact member about the pivot to make or break the electrical circuit.

One embodiment of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a sectional view of a flashlight embodying the invention, Figure 2 is a fragmentary sectional view of the switch and its actuating member in its "off" position, and Figure 3 is a fragmentary sectional view of the switch and its actuating member in its "on" position.

Referring to the drawings, a flashlight is shown comprising an elongate plastics casing 10 housing in a conventional manner two dry cells 11 disposed in series between one contact 12 of a holder 1 3 for a bulb and a coil spring 1 4 seated against a metal base element 1 5. A first contact strip 1 6 has one end connected to the base element 1 5 and extends alongside the dry cells 11 to a switch carrier 1 7 made from an insulating plastics material. The other end of the strip 1 6 is secured to the carrier 1 7 by a rivet 1 8.

Contact 1 2 is electrically connected to a contact element 20 of the bulb holder which element 20 is in turn in contact with one end of a second contact strip 21. The other end of the strip 21 is secured to an upstanding portion 23 of the carrier 1 7 by a rivet 22.

A switch 1 9 is mounted on the carrier 1 7 and the casing 10 and extends between the rivets 18, 22 secured to the carrier. The switch 1 9 comprises a rigid ferrous member 25 which is pivoted about a point near its centre in a metallic pivot stand 28, which pivot stand is formed integrally with a metallic bracket 28a secured to the carrier 1 7 and in electrical contact with contact strip 16, and a contact member 24 secured to member 25 by rivets 26, 27, said rivets being disposed at similar distances on either side of said pivot stand 28. The end 29 of the contact member 24 extends beyond the ferrous member 25 and is bent upwards.The end 29 is below and is in mutually overlapping relationship for movement into and out of electrical contact with the underside of the extremity of the contact strip 21 projecting beyond the rivet 22. The opposite end of the contact member is always spaced from the bracket 28a and from the extremity of the contact strip 1 6 projecting beyond rivet 1 8.

A switch actuating member 30 is mounted for guided sliding movement along a dovetail section guideway 31 on the outside of the casing 10 closely adjacent the switch 19, the direction of sliding movement being parallel to the lengthwise dimension of the contact member 24. A magnet 32 is secured in a cavity on the underside of the actuating member 30.

In one of the end positions of the actuating member 30, as shown in Fig. 2, the magnet 32 is disposed over a rear portion 33 of the ferrous member 25 and the magnetic flux attracts the rear portion 33 of the ferrous member 25. The contact member 24 and the ferrous member 25 rotate in an anticlockwise direction about the metallic pivot stand 28 and move the end 29 of the contact member 24 out of contact with the extremity of the contact strip 21. The switch is shown in the "off" condition in Fig. 2.

When the actuating member is moved into its other end position, as shown in Fig. 3, the magnet is disposed over a front portion 34 of the ferrous member 25 and the magnetic flux thus attracts the front portion 34 of the ferrous member 25. The contact member rotates in a clockwise direction about the metallic pivot stand 28 and causes the end 29 of the contact member 24 to make contact with the extremity of contact strip 21. An electrical circuit is thus established and the switch is in the "on" condition.

This form of switch is particularly advantageous for dry-cell powered flashlights and lanterns designed for underwater and industrial use since the switch arrangement requires nothing to extend physically through the wall of the casing 10. The torch can thus be made both water and air tight. It will be understood that the switch arrangement can be employed advantageously in many types of dry-cell powered flashlights, lamps and lanterns.

Claims

1. An electric lighting device comprising a casing which houses a bulb holder and which incorporates a compartment for one or more dry cells, and contact means for connecting the cell or cells in circuit with the bulb holder which means includes a switch disposed within the casing, said switch comprising a contact member pivoted for rocking movement into a first position in which the contact member completes said circuit and into a second position in which the contact member interrupts said circuit, and a switch actuating member carrying a magnet and mounted on the outside of the casing for guided movement selectively into each of two locations in one of which the magnet causes the contact member to rock into said first position and in the other of which causes the contact member to rock into said second position.

2. A device as claimed in Claim 1 wherein the contact member is pivoted intermediate its ends and has a contact point at one end and a contact point at its pivot for completing said circuit, which contacts are electricallly connected together.

3. A device as claimed in Claim 2 wherein the switch is mounted on a carrier attached to the casing and the contact member comprises a ferrous member pivotally mounted on the carrier for said rocking movement, one end of said ferrous member being attracted by the magnet when the switch actuating member is in its first location and the other end of said ferrous member being attracted by the magnet when the switch actuating member is in its second location thus producing the rocking movement of the contact member about the pivot to make or break the electrical circuit.

4. An electric lighting device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.