US 4,062,578 AGranted

Door safety latch

AssigneeTrepege Products Inc.

InventorTrevor G. Chen

Life of this patent

Estimating the term…

Loading patent…

Abstract

A door safety latch permitting the partial opening of a door consisting of an arcuate lug mounted on the door, and having an enlarged ball portion mounted on the end thereof, with a fastening member mounted in the door frame having a pivoted yoke portion whose spaced apart leg portions prevent the ball portion of the lug from passing therethrough. At the pivoted end of the yoke portion, the leg portions are sufficiently spaced apart to permit the ball portion to pass therethrough. When the door is in a closed position and the safety latch swung to the position to permit only a partial opening of the door, the arcuate lug will extend through the space between the leg portions. In order to prevent the pivoting of the yoke by a person on the outside of the door, as by a burglar, means are provided offering frictional resistance to the turning movement of the yoke so that he is unable to cause the yoke to swing from its door locking position to the position that permits the door to open to its completely open position.

Claims1

Dependent claims

A door safety latch comprising substantially arcuate lug means adapted to be mounted on a door, a substantially enlarged head mounted on the free end of said lug means, a base member adapted to be mounted on a wall adjacent said lug means, yoke means having spaced apart leg portions, means pivotally mounting free ends of said leg portions to said base member, a plurality of stepped surfaces mounted on said free end of one of said leg portions, said leg portions being sufficiently spaced apart adjacent to said pivot means to permit said enlarged head to pass therethrough and the rest of said leg portions being only sufficiently spaced apart to permit said lug means to slide therethrough and detent means mounted at said pivot means providing substantial resistance to the pivotal movement of said yoke means, said detent means having a bore in said base member in substantial alignment with said stepped surfaces, a substantially elongated detent member secured in said bore having a free end portion engaging said stepped surface, said detent member having a substantially pointed free end portion and being reduced in diameter in proximity of its mid-portion permitting said detent member to bend at said mid-portion to become foreshortened as said stepped surfaces move past said detent member upon applying increased forces at said yoke means, said detent member engaging one of said stepped surfaces upon the partial opening of said door.

Dependencies are inferred from the claim text.