Patent ID: 8499900

Claim:
A retarder for controlling the speed of a railcar, the retarder comprising: first and second levers that are both pivotable about a common axis between an open position and a closed position, wherein the first and second levers each have a first end and a second end, wherein the first and second levers are oriented with respect to each other so that the respective second ends of the first and second levers oppose each other and define a space there between for receiving a wheel of the railcar; brakes disposed on the second ends of the first and second levers for engaging and braking the wheel of the railcar; and a hydraulic piston-cylinder and a spring coupled together and disposed between the first ends of the first and second levers; a first bracket disposed between the piston-cylinder and the spring; wherein the piston-cylinder has a first end that faces a first side of the first bracket and a second, opposite end that faces the first end of the first lever; wherein the spring has a first end that faces a second, opposite side of the first bracket and second end that faces the first end of the second lever; wherein supplying pressurized hydraulic fluid to the piston-cylinder causes the piston-cylinder and the spring to move the brake towards a closed position in which the brake will apply braking pressure on the wheel of the railcar and wherein the spring resiliently biases the brake into the closed position to maintain a substantially constant braking pressure on the wheel as it moves through the retarder.