Patent ID: 8307503

Claim:
A self-closing hinge comprising: a stationary assembly comprising a hollow cylindrical tube having a first end and a second end having a clutch stationary assembly secured thereto; a first torsional spring positioned within said tube and secured at the first end thereof, and having a pin secured at a second end of said first torsional spring whereby said spring biases said pin in a first direction and whereby said pin rotates to engage said clutch stationary assembly at a at least one point; a rotating intermediate tube assembly comprising a generally hollow cylinder having a first end positioned over said stationary assembly, and a second end having a clutch rotating assembly, whereby said pin of said first torsional spring engages said clutch rotating assembly at a point; an exterior tube assembly comprising a generally hollow cylinder having a first open end positioned over said intermediate tube assembly and a second closed end, and a second torsional spring positioned between and secured to said intermediate tube assembly and said exterior tube assembly; said clutch stationary assembly having a pair of spaced stops against which the pin of said first torsional spring abuts when completely rotated in a first direction to inhibit further rotation; said clutch rotating assembly having a recessed portion in which said pin is permitted to rotate, and a pin stop that rotates with said clutch rotating assembly until it abuts a one of said stationary assembly stops, thereby inhibiting further rotation of said rotating assembly; said exterior tube assembly having a cylindrical flange disposed on said first end, for engaging the first end of said intermediate tube assembly, and permitting rotation of said exterior tube assembly with respect to said intermediate tube assembly; and a viscous fluid disposed between said exterior tube and said intermediate tube to slow rotation of said tubes relative to each other.