Anti-tamper fastener shielding apparatus

摘要

Apparatus for assembly with a bolt or screw upon installation thereof to prevent tampering therewith, including a one piece collar device having an outer annular jacket member with a restricted collar portion and an inner annular washer member detachably joined to the jacket member at the collar portion by a frangible diaphragm. The stem of a bolt or screw is inserted through the collar device and tightened into engagement with the collar portion to cause shearing of the diaphragm to separate the washer and jacket members, the washer member being of a larger axial dimension and smaller radial dimension than the collar portion to permit the jacket member to rotate freely about the bolt or screw and the washer member when the enlarged fastener head is tightened into clamping engagement with the washer member. A cap member fits snugly in the free end of the jacket member to enclose the fastener head. Thus, the fastener head cannot be frictionally clamped by gripping the exterior of the rotatable jacket member to deter tampering with the fastener.