Safety lock on entrance door

Abstract

In one form, a safety lock for a knob operated door includes an anchor block fastened to the framing stud of door frame. A flexible steel cable loop having a pair of parallel end portions permanently mounted in the anchor block has a cylindrical shank tightly encompassing its parallel end portions, the shank being situated in adjacent relationship to the anchor block. A cylindrical sleeve encompasses the shank and is in rotatable and longitudinally slidable relationship with respect to it. The anchor block is so situated that, when the sleeve is in encompassing, overlying relationship to the shank, the cable loop will just barely fit over the maximum diameter of the knob. With the loop aligned with the reduced portion of the knob, the sleeve is slid toward the knob to reduce the size of the loop so it cannot come back over the knob. The sleeve and the shank are so positioned as to be in alignment with the vertical slot between the door and the door frame when the safety lock is operative. In another form, the anchor block and cylindrical shank are constituted as one integral piece.

Dependencies are inferred from the claim text.