GB800434A - Improvements in and relating to switches for electric torches - Google Patents

Abstract

800,434. Electric battery lamps. SONG & CO., Ltd., V. K. Oct. 15, 1956 [Oct. 20 1955], No. 30043/55. Class 39(2) [Also in Group XXXVII] A switch unit for attachment to the casing of a torch or battery lamp comprises a switch box or body 2 made of aluminium, aluminium alloy, or like soft metal, a slide 3 mounted on the box or body 2 and slidable longitudinally thereof, and a resilient member or slide spring 4 carried on the underside of the slide 3 and provided with a dimple 4a adapted to engage with at least one rounded projection 8a formed on the surface of a strip 8 of harder material secured to the relatively soft metal of the switch box or body, thereby obviating the wear that would otherwise result from the projection 4a engaging the aluminium surface of the switch box 2. As shown, an aluminium switch box 2 secured at one end to a torch case 1 by a tongue 2a engaging within a slot in the box, and at the other end by a rivet 10, carries a switch slide 3 also made of aluminium. The slide 3 is held to the box 2 by legs 3a, Fig. 3, which extend through longitudinal slots in the top of the box and also engage within smaller slits in a movable contactor strip 7 which can thus be moved longitudinally with the slide 3. A bridge strip 8 of a metal that is harder than aluminium, e.g. brass or steel, is fixedly secured to the switch box 2 by passing its edges through slots in the box and bending them inwardly, and the strip 8 and the part of the box 2 beneath it are pressed to form two dimples 8a, this being effected prior to the attachment of the slide 3. As shown, the slide 3 is in the "off" position. Movement of the slide to the right, so that the dimple 4a on the spring 4 is located between the two dimples 8a, places the switch in the "flash" position whereat depression of a flashing-button 9 brings the adjacent end of the movable contactor 7 into contact with the part 5a of a stationary contact strip 5 connected in the bulb circuit. Further movement of the switch slide to the right brings it into the "on" position, with the contactor 7 in contact with the portion 5b of the strip 5. Movement of the switch slide to the different positions is indicated by an accompanying clicking sound. A thin fibre sheet may be located between the slide 3 and the switch box 2 to prevent scratching of the latter. In a modification, the flashing arrangement is dispensed with and the bridge strip 8 has only one dimple 8a, which provides a click when the slide is moved between "on" and "off" positions. Alternatively, the movable contactor 7 and the stationary contact strip 5 may be replaced by a single strip which is movable longitudinally into contact with the reflector for the "on" position.