Abstract: A material handling device such as a pump, including a first housing part 12 having an internal surface 12A surrounded by a peripheral surface 12B, 12C facing in generally the same direction as the internal surface. A substantially longitudinally inextensible flexible diaphragm has its periphery clamped on the first clamping surface by a cooperating second clamping surface 16B, 16C, the second housing part 16 carries a rotary member 17 on which are mounted three rollers 18. A chamber 10 is formed between the diaphragm and the internal surface. Upon rotation of the rotary member, the rollers sequentially urge the diaphragm onto the internal surface to form a constriction which traverses the chamber and moves the constriction from one port 13 to another port 14 formed in the first housing part.

Abstract: A material handling device such as a pump, including a first housing part 12 having an internal surface 12A surrounded by a peripheral surface 12B, 12C facing in generally the same direction as the internal surface. A substantially longitudinally inextensible flexible diaphragm has its periphery clamped on the first clamping surface by a cooperating second clamping surface 16B, 16C, the second housing part 16 which carries a rotary member 17 on which are mounted three rollers 18. A chamber 10 is formed between the diaphragm and the internal surface.Upon rotation of the rotary member, the rollers sequentially urge the diaphragm onto the internal surface to form a constriction which traverses the chamber and moves the constriction from one port 13 to another port 14 formed in the first housing part.