Patent ID: RE40219

Claim:
A pump of type comprising: a support, a moving member mounted to move relative to a said support, the moving member having a central duct into which the a substance to be dispensed penetrates via at least one opening, the support cooperating with the moving member to define a variable volume pump chamber around said central duct, the pump also having a diaphragm having a central portion in the form of a sleeve with a top and a lower ends that is open at its the top end and closed at its bottom the lower end, said central duct being inserted in said central portion sleeve , the diaphragm being organized in such a manner as configured to isolate the at least one opening s of the pump chamber when the volume of the pump chamber increases arid and the substance is sucked into it therein , wherein the bottom lower portion of the central portion of the diaphragm sleeve presents, at least over a sector of its periphery, a at least one preferred deformation zone.