US 4,057,275 A · Door jamb reinforcing plate

Abstract

An elongated metal plate for fastening to the back of a wooden door jamb with a plurality of fastenings including an angled side of the plate recessed into the jamb, another angled penetrating side driven into the jamb, and a plurality of screws driven through the metal plate intermediate the recessed and penetrating sides. The fastenings are longitudinally and transversely spaced apart to provide maximum reinforcing strength without a concentration of the plurality of fastenings sufficient to weaken the wooden jamb where its bulk has been reduced by hollowing to receive a latch bolt. After the metal plate has been fastened to the back of the jamb, the jamb is fixed to blocking structure of a doorway with the metal plate therebetween and out of reach of tampering. As reinforced by a locked door in the doorway, the whole jamb must be broken transversely against its wood grain in order to force the door.

Claims5

Dependent claims

In combination with a doorway having wooden jambs and a door adapted to swinging inwardly and outwardly therebetween, each jamb with an oppositely disposed front and back, and one jamb defining a hollow in front for receiving a latch bolt of said door, a jamb protector for said one jamb comprising:

a reinforcing plate having two contiguous sides with a common longitudinal edge defining a ninety degree angle between said sides, a first and narrower of said two sides for recessing into the back of said one jamb and outwardly, as said door swings, in said hollow and the second and wider of said two sides, defining a plurality of fastening holes, for placing against the the back of said one jamb;
a third and discontinuous side parallel and opposite to the first and narrower side and defined by a plurality of longitudinally spaced triangular points for penetrating into the back of said one jamb;
and a plurality of individual fastenings adapted to engage through said fastening holes into the back of said one jamb, whereby the reinforcing plate is fixed to the back of said one jamb against separation therefrom in all directions by each side and strengths the jamb against splitting, splintering and kick-outs in attempts to force said door.

Dependencies are inferred from the claim text.

Door jamb reinforcing plate

Life of this patent

Door jamb reinforcing plate

Life of this patent

Abstract

Claims5