Bolt tamper sensor

Abstract

An electromechanical sensor for use with an alarm system, comprises a housing containing upper and lower conductive components, for example flanged washers. The upper and lower conductive components are elastically separated and are compressibly displaceable from a first closed circuit position to a second open circuit position by the installation and tightening of a bolt through the sensor. The upper and lower conductive components are electrically isolated from the housing by at least one non-conducting sleeve when the conductive components are compressed into the second open circuit position by the bolt tightening. At least one of the upper and lower conductive components comes into conductive contact with the housing when the bolt is withdrawn, compression reduced and the conductive components are allowed to expand into the first closed circuit position.

Dependencies are inferred from the claim text.