Latch guard

Claim 1

In a latch guard having a mounting flange mountable in overlying relation to the inner face of a jamb in the vicinity of keeper means located on the jamb, and a blocking flange integrally fixed along one edge of the mounting flange substantially at right angles thereto so as to lie in a first plane paralleling, and adapted to overlie the abutment face of a jam-mounted stop, the blocking flange projecting laterally on a side of the mounting flange facing the door, the mounting flange having an enlarged recess defined centrally therein, the improvement wherein a portion of the blocking flange projecting along and beyond the full length of the recess in a direction away from the door has a plurality of toothed segments formed therein, and further comprising a conductive plate lying in a second plane paralleling the first plane and normally spaced therefrom in a direction away from the door, and at least one non-conductive compression spring being interposed between said plate and said blocking flange for urging said plate in a direction away from said blocking flange, and wherein the stop and the jamb are formed with first and second recesses, respectively to receive said blocking flange, said spring, and said plate, and wherein the blocking flange and said plate are formed with projections facing one another, respectively, the blocking flange is conductive, and the latter and said plate are adapted to be electrically coupled to an intruder-actuated warning means, respectively, whereby, upon an intruder attempting to selectively jam a prying tool between the jamb and the stop, and between the door and the stop, said projections make electrical contact with one another and actuate said warning means.