Abstract: A device designed to effect automatic activation or deactivation of electrically, hydraulically or pneumatically operated control means, comprising a body freely movable in an air-tight housing and in its normal position sealing an aperture, a spring-biased control member arranged in a conduit one end of which is connected to the chamber and the opposite end of which is closed by said control member, which member may be displaced in said conduit between an activating and a deactivating position, said displacement effected by the pressure differential or the pressure blance in said conduit on the opposite side of said control member arising as a consequence of said body being forced from its aperture-sealing position upon tilting of the housing past a predetermined angle or upon acceleration or retardation of a certain magnitude of said housing.