GB1526208A - Electrical switch - Google Patents

Abstract

1526208 Mechanical switches LUCAS ELECTRICAL CO Ltd 8 Dec 1975 [24 Dec 1974] 55750/74 Heading H1N A switch for a vehicle hazard warning system, for example, has a rectilinearly slidable operating member 13 with two conductive bridges 24 and 25 each co-operating with a respective pair of fixed contacts 15, 16 and 17, 18 in a body 11 so arranged that in a first position of member 13 one bridge 24 interconnects its fixed contacts 15, 16 while the second bridge 25 is out of engagement with at least one of its fixed contacts, and in a second position of said member 13 the second bridge 25 interconnects its fixed contacts 17, 18 while the first bridge 24 is held out of engagement with at least one of its fixed contacts by a ramp 27 carried by the body 11. In the embodiment shown the bridge 24 is a brass plunger and bridge 25 is a brass plate each being urged outwardly by a common spring 26 therebetween, the plate 25 being shaped, at 25b, for additional engagement with one contact 19 of a further pair of contacts 19, 22 and member 13 carries a lamp (14, Fig. 3, not shown) which has one contact in permanent sliding engagement with a contact 21 and its other contact connected to a resilient conductive member having arms 28, 29 co-operating with fixed contacts 19, 22. The fixed contacts 17, 18, 19 are shorter than contacts 15, 16, 22 such that in the first position of member 13 the moving contacts 25 and 29 do not engage them, while in the second position of member 13 ramp 27 lifts plunger 24 away from both fixed contacts 15, 16 and another ramp (31) lifts contact 28 away from contact 22. Detent members (not shown) locate member 13 in its two positions. In a second embodiment (Figs. 4 and 5, not shown) the moving contacts comprise conductive balls (53, 54, 55, 56), mounted at the free ends of resilient blades (51, 52) carried on the slidable operating member, to interconnect fixed contacts 42, 43, 44 and 45, 46, 47 respectively. In this embodiment the operating member is provided with a return spring (49) and is located by a detent mechanism (not shown) of the push-push type. In each embodiment the fixed contacts extend through the base of the switch body to form terminal pins.