illustrated it should be obvious to one skilled in the art that the right side adapter is a mirror image thereof adapter 22 24 is preferably manufactured from die cast zinc although other types of metal such as aluminum or possibly a strong injection molded plastic may also be used adapter 22 24 includes pintle or spindle 56 that is received within opening 54 of hinge assembly 16 and a joining element 58 that includes screw holes 64 in alignment with holes 48 of base member 12 for securing the adapter to the base member with screws disposed between spindle 56 and joining element 58 is a middle portion 60 around which torsion spring 18 20 is wound as shown most clearly in fig2 a liner 28 preferably made from a nylon or plastic material may be disposed between spindle 56 and torsion spring 18 20 in order to avoid the noise caused by contact between the torsion spring and the spindle of the adapter adapter 18 20 further includes limit stops 72 projecting from spindle 56 limit stops 72 contact the interior cowling 74 within opening 54 of hinge assembly 16 and thereby prevent the continued rotation of spindle 56 preferably spindle 56 rotates between 49.