Patent ID: 7900978

Claim:
A return spring assembly adapted for installation in a bored opening in a door, the return spring assembly comprising: a spring housing including: an outer flange having a first surface for making fixed supporting contact with a face of the door and a second surface opposed to the first surface and facing away from the door, the outer flange having a diameter greater than a diameter of the bored opening in the door; and an inner portion having a diameter less than the diameter of the bored opening in the door, the inner portion extending from the first surface of the outer flange at least partially into the bored opening in the door and away from the second surface of the outer flange when the first surface of the outer flange is in contact with the face of the door, the inner portion including: a curved section extending less than one hundred eighty degrees around a perimeter of the inner portion and away from the second surface of the outer flange, the curved section extending more deeply into the bored opening than the remainder of the inner portion when the first surface of the outer flange is in contact with the face of the door; and an annular spring channel, the annular spring channel, inner portion and outer flange of the spring housing being fixed relative to each other and to the door when the first surface of the outer flange is in contact with the face of the door during all operating states of the return spring assembly; a compression spring located within the spring channel, the spring being located within the bored opening in the door when the outer flange is in supporting contact with a face of the door; and a first spring driver having an arm engaging a first end of the spring and a second spring driver having an arm engaging a second end of the spring, each spring driver including a center shaped opening to engage a spindle driven by a handle whereby the center shaped opening of each spring driver is larger than a cross section of the spindle to provide a lost motion engagement between the spring driver and the spindle, the first spring driver moving independently of the second spring driver as the handle is rotated in a first direction to compress the spring from the first end of the spring and the second spring driver moving independently of the first spring driver as the handle is rotated in an opposite direction to compress the spring from the second end of the spring.