Abstract: A sliding door assembly comprising a door hanger, a hanger sheave, an upthrust roller and a track, wherein the hanger sheave assembly and the uptrust roller are rotatably mounted on the door hanger. The track provides a first rolling surface for the hanger sheave and a second rolling surface for the upthrust roller. The track also preferably captures the upthrust roller thereby preventing the assembly from leaving the track.

Abstract: A hydraulic door opening or closing device comprises a hydraulic fluid pump motor having two ports connected to each end of integral dual manifold and operating cylinder apparatus by way of two branch fluid lines. One branch line is fluidly connected to a particular end of the operating cylinder by way of a directional flow valve. The other branch line to the same end of the cylinder is fluidly connected to the cylinder by way of an associated manifold. Fluid communication with the cylinder through the manifold is accomplished by providing a plurality of valved openings linearly disposed along the end of the cylinder between the manifold and the cylinder. As a piston of the operating cylinder passes these openings, a door coupled to the piston is automatically slowed as fluid on the drive side of the piston is returned through the openings to the hydraulic fluid pump.