GB1427520A - Electrical switch - Google Patents

Abstract

1427520 Indicators for switches BONNELLA SWITCHES Ltd 16 May 1973 [16 May 1972] 22910/72 Heading H1N A switch comprising a housing 12 carrying an opaque rocker type operating member 13 includes an indication panel (25) (Fig. 2, not shown) in one of the rocker operating faces which is illuminated from behind the rocker by means of light from an external source entering an aperture 27 and being conducted within the switch by a light-conducting element 28, Fig. 4. The light-conducting element 28 is a uniform plate of transparent or translucent synthetic resin shaped for close fitting within upstanding opaque walls provided within the housing and having a tongue 30 extending into the aperture 27. A slot 34 provides for the passage of a switch actuating member and shaped edges 29, 35 and 32 together with an opaque white reflective backing layer all combine to direct the incident light received by the tongue towards areas 37 whence it is received in a diffused manner behind the panel 25 and at a similar location behind the other operating face of the rocker, the upper surface of the tongue 30 being covered with an opaque strip 36 to prevent the passage of direct rays. The symmetry of the illumination channels enables two similar switches to be disposed on opposing sides of a common light source with one of the rockers being inversely assembled. Instead of the reflective opaque layer on element 28 the base surface of the housing immediately behind the element may be made reflecting.