Abstract: A hydraulic master cylinder piston carries a circumferential seal ring which allows recuperation flow valving. The floating seal has a reinforcing metal girdle which prevents radial expansion and axial crushing. The seal material resists extrusion and has an outer radius slightly greater than the radius of the circumferential girdle. A forward slotted bearing ring maintains the piston in alignment with the bore. During piston return, recuperation occurs through a path comprising the radial clearance between piston and floating seal ring and at least one slot or groove in the bearing ring. Upon full piston return, the seal is withdrawn from the master cylinder working chamber into a larger diameter bore communicating with the reservoir and thus allows relatively free make-up flow.

Abstract: A barge tipper comprises a cylindrical floating apparatus 10 defining a chamber 18 into which a barge 28 can be floated. End doors 16 at either end of the apparatus 10 are closed and the barge 28 is clamped in position by hydraulically operated clamps 20. Water is pumped from the chamber 18 to ballast tanks 12 and 14, causing the apparatus to rotate and thus tipping the barge 28. The contents of the barge 28 flow into a first conveyor 22 and are delivered to a second circumferential conveyor 24 which feeds the material to an external conveyor 26.