A hinge locking system is provided for locking pivotable hinge parts at a desired angular position relative to one another. The hinge locking system includes a locking pin, a plate with a locking pin receiver, a movable pin receiver defining an axial bore for receiving the locking pin, and a pair of spaced-apart limit stops along the plate. The movable pin receiver is movable relative to the plate, and the limit stops are selectively contacted by the movable pin receiver to limit the maximum relative movement of the movable pin receiver. When the axial bore of the movable pin receiver aligns with the plate's locking pin receiver, the locking pin is insertable through the locking pin receiver and the axial bore in the movable pin receiver, to thereby lock the movable pin receiver and the hinge parts against further movement.
