Arthur L. Plevy - East Brunswick NJ
A gravity operated intrusion sensing device comprises a mercury tilt switch having at least two operating modes and a stationary housing having means operative to support the tilt switch in a first position indicative of one operating mode and to provide a second position indicative of another operating mode. The switch is responsive to an external force applied to the housing and falls under the influence of gravity as constrained by the housing to the second position. The entire switch actually falls freely within the stationary housing as to the second position. The second position as dictated by the housing produces a tilted plane at which the switch, after falling, comes to rest, thus assuring the proper operating angle to cause the proper tilt so that in the second position the switch will be in a completely different state, as opened or closed, as compared to the state in the first position.