Patent ID: 6905314

Claim:
A pump for pumping a fluent material comprising: a liner including opposing walls of flexible material defining a plurality of pump cells, an inlet and an outlet, the pump cells being sized and shaped for receiving a quantity of the fluent material and being expandable for receiving fluent material and contractible for discharging fluent material; a rigid shell adapted to receive and substantially enclose at least the pump cells of the liner, the shell being formed with a plurality of receptacles therein to receive in close fitting relation the pump cells, said receptacles being adapted for connection to a source of pressurized gas and for connection to a vacuum source for selectively applying a vacuum pressure and a positive pressure to the cells to selectively expand and collapse the cells for drawing fluent material into the pump cell and expelling the fluent material from the pump cells; valves associated with the rigid shell and disposed for pinching engagement with the liner adjacent to the pump cells for selectively blocking and opening fluid communication of the pump cells thereby to pump the fluent material.