GB1455357A - Inertia switch devices - Google Patents

Abstract

1455357 Inertia switches; thermal switches JAEGER 26 March 1974 [26 March 1973 31 Jan 1974] 13425/74 Heading H1N An inertia switch, for controlling safety devices in a vehicle for example, comprises a covered casing 1 containing on the bottom 3 thereof an inertia mass 2 of a size permitting lateral movement within the casing, a partition 4 being spaced from the bottom 3 by a distance substantially equal to the height of the mass 2, said mass having a central conical recess 5 in which is engaged an elongate contact actuator member 6 loaded by a spring 20 therein which bears directly or indirectly on the cover 8 of the casing via an adjusting screw 10, whereby a predetermined acceleration or deceleration causes lateral movement of the mass 2 and produces a self-retaining change in the condition of contact members 12, 13. In a first embodiment the switch is reset by depressing button 9 which urges collar 16 back to the position shown in Fig. 1 after it has been lifted on shoulders 18 by lateral movement of mass 2. The plunger 6 may be conductive and collar 16 insulating, or vice versa. In the latter case the contacts are broken on impact and collar 16 has insulation on its lower face, or one contact member is longer so as not to engage the collar after actuation. In a second embodiment (Fig. 3) one contact member 13 is of bimetal and hookshaped at 21 to latch under conductive ring 11 after impact sufficient to lift plunger 6 adequately. Current flowing in member 13 causes it to release 6 after a time delay which is adjustable by screw 23.