Abstract: A pair of leaf hinges have respective knuckles in axial alignment providing respective axially aligned chambers for reception of a pintle serving as a pivot for the hinges. The pintle is provided with a keying rib, and grooves in the respective knuckles and are in alignment only when the hinge is rotated to extreme position to permit insertion of the pintle and the keying rib into operative position within the knuckles. When the hinge is installed on a door and the door mounted on a frame, the door can not normally be swung to a position wherein the grooves are in alignment so that the pintle can not be removed from the hinge as long as the door stays in mounted position on the frame.

Abstract: A tension spring motor for use in a pintle or cartridge like container is employed to return hinged parts to an initial position after having been rotated to a second position. Door hinges are a typical example where a spring automatically returns the door to closed position after it has been opened. To vary the tension in the spring use is made of a pair of notched members housed within the pintle, one being a fixed member and the other being a movable member attached to the spring and rotatable to different positions of adjustment. A wrench hold in the movable member is accessible from the outside through a hole in the fixed member.