Patent ID: 8245368

Claim:
A fastener, comprising first and second fastener units configured to be releasably attached to one another, wherein the first fastener unit comprises a ring wherein a radial diameter in an inclined inner surface thereof narrows in a downward axial direction of the ring; and wherein the second fastener unit comprises: an upper plate defining a notched cylinder configured to abut the inclined inner surface of the ring; a lower plate coupled to the upper plate, the lower plate comprising a pivotal push rod; and a push plate engaged with an inner surface of the upper plate within the ring, the push plate operable by a user to press the push rod in a downward direction such that the pivotal push rod presses the ring in an upward direction to move the ring upward; the push plate comprising a protrusion configured to press the notched cylinder against the inner surface of the ring when the fastener units are attached to one another and the push rod biases the push plate upward to lock the notched cylinder between the ring and the push plate, and to release the notched cylinder when the push plate when the push plate is operated by the user.