Patent ID: 7743468

Claim:
A hinge assembly comprising a combination bracket having a top; a bottom; and two sides; a keyed shaft being attached securely below and protruding down from the combination bracket and having an upper end; a lower end; and a middle; a stationary bracket being mounted rotatably around the keyed shaft and having a top surface; two edges; a pivot hole being formed through the stationary bracket and being mounted rotatably around the lower end of the keyed shaft; and a limit being formed on and protruding up from the top surface of the stationary bracket, being curved and concentric with the pivot hole and having a first angle; a limiting assembly being mounted around the keyed shaft against the top surface of the stationary bracket, corresponding to and selectively abutting the limit and having a limiting ring being mounted rotatably around the keyed shaft against the top surface of the stationary bracket and having an outer edge; a through hole being formed concentrically through the limiting ring, being mounted rotatably around the keyed shaft and having an inside edge; a second state stop being formed on and protruding radially from the outer edge of the limiting ring, corresponding to and selectively abutting the limit and subtending a second angle; and at least one first stage limit notch being formed in the inside edge of the through hole of the limiting ring, and each one of the at least one first stage limit notch having two ends and subtending a third angle being greater than a combination of the first angle and the second angle; and a driving ring being mounted non-rotatably around and engaging the keyed shaft, being mounted rotatably in the through hole of the limiting ring and having an outer edge; a keyed hole being formed concentrically through the driving ring and engaging the keyed shaft; and at least one first stage stop being formed on and protruding radially from the outer edge of the driving ring, corresponding to and being mounted rotatably in the at least one first stage limit notch, selectively abutting ends of the at least one first stage limit notch and subtending a fourth angle being smaller than the third angle of the first stage limit notch, and the third angle minus the fourth angle being equal to the first angle plus the second angle; and a pressing assembly being mounted around the lower end of the keyed shaft below the stationary bracket and holding the limiting assembly in the stationary bracket.