GB1511650A - Electrical switch assemblies - Google Patents

Abstract

1511650 Mechanical switches LUCAS ELECTRICAL Ltd 26 Aug 1975 [12 Sept 1974] 39742/74 Heading H1N An electrical switch assembly comprises first and second operating members 12, 13 rectilinearly movable relative to a housing 11 for operating respective switch contacts, a wall 14 of the housing 11 extending between the two members 12, 13 and having a transverse slot (15) (Fig. 6, not shown) along which is movable a blocking element 16 having each end co-operable with a respective one of the operating members 12, 13 such that the second operating member 13 is prevented from moving from a first to a second position before the first operating member 12 has been moved to its second position and the first member 12 is prevented from moving back to its first position before the second operating member 13. The first and second operating members 12, 13 operate the sidelamps and headlamps respectively of a vehicle so that the sidelamps must switched on before the headlamps and switched off after the headlamps. One end of the blocking element 16 is received in an inclined groove 17 in the operating member 12 and the other end of the element 16 is engageable with a vertical groove 18 in the member 13. When the operatmember 12 is in the off position the element 16 is displaced from the groove 18 and prevents movement of the operating member 13 to its on position. When the operating member 12 is moved to its on position in which it is retained by a detent against spring bias, the element 16 is moved along the slot (15) in the housing wall 14 to a position aligned with the vertical groove 18 allowing the operating member 13 to be moved to its on position. In the on position of the two operating members 12, 13 the groove 18 prevents movement of the element 16 along the slot 15 and groove 17 of the operating member 12 which cannot therefore be moved back to its off position while the operating member 13 remains in an on position.