Door hinge with bolt between rolled flaps - has sloping socket edges so that swivelling flap rises spirally and returns automatically

摘要

The flat, swivelling door hinge has flaps linked by a bolt, which is housed in rolled sockets on them. On one flap (1), the tops of the rolled sockets (11) have an edge slope (121), and on the other (2) the bottoms have a corresponding edge slope. Between the non-sloping tops and bottoms there is an interval, corresponding to the pitch. Swivel of one hinge flap, relative to the other, about the bolt (10), results in helical vertical movement of the swivelled flap. On completion of swivel, this flap returns to its original rest position, under gravity.