US Patent 7828349 Resilient device for door handle and knob

The resilient device contains two intermediate plates stacked and sandwiched between two outer plates. The intermediate plates have a center opening for accommodating a rotational seat and a spiral spring in the gap between the rotational seat and the intermediate plates. The ends of the spiral spring are attached to the rotational seat and the intermediate plates, respectively. An axle of a door knob or a door handle runs through the outer plates and engages a saw-toothed center opening of the rotational seat. When the door handle or door knob is turned, the spiral spring is tightened as the rotational seat is turned along with the door handle or door knob. When the door handle or door knob is released later, the spiral spring expands and therefore restores the door handle or door knob back to its original, un-turned state.