Patent ID: 7117975

Claim:
An elevated location descent apparatus comprising a descending device, a braking device and a power transmitting device, the descending device comprising sprockets positioned in a vertical plane, a suspension chain positioned around the sprockets and a payload-suspending means attached to the suspension chain, the braking device comprising a fluid pump converting the rotational movement of a crankshaft into the reciprocal movement of pistons, which reciprocal movement causes the fluid pump to receive a fluid from an inlet and discharge the fluid through an outlet, a fluid circulating conduit connecting the outlet of the fluid pump with the inlet of the fluid pump in which the fluid discharged from the fluid pump circulates, a flow-restricting valve adjusting the amount of the fluid passing through the outlet of the fluid pump to generate the fluid resistance, and a rotational governor controlling the flow-restricting valve based on the rotational speed of the sprocket, the power transmitting device comprising a transmission means that transmits the rotational force of the sprocket of the descending device to the crankshaft of the braking device, the elevated location descent apparatus being designed to apply braking force to the rotation of the sprocket of the descending device by controlling the flow-restricting valve through the use of the rotational governor to vary the fluid resistance applied to the compressing movement of the pistons in accordance with the rotational speed of the sprocket generated by the weight of a payload when the payload is attached to the suspension chain.