Patent ID: 7070400

Claim:
A diaphragm pump, comprising an elastic pump diaphragm which is driven by a motor via a crank mechanism by means of a connecting rod and which spans a pump chamber provided in a base plate, wherein a pump chamber wall provided in the base plate extends in a conically widening manner from a central flat base section to a side edge thereof, and the diaphragm spanning the pump chamber is configured and arranged in such a way that it bears substantially tightly against the entire pump chamber wall and the side edge thereof, at a top dead center position of the connecting rod, with the result that there is substantially no remaining dead space at the top dead center position of the connecting rod, the diaphragm being made of substantially inherently stiff elastic material of predetermined thickness and configuration, and its deformation, with simultaneous pre-tensioning, for adaptation to the pump chamber wall and the side edge of the pump chamber upon the connecting rod's stroke in the direction of the top dead center position, being ensured by a single first circularly extending recess in a rear wall of the diaphragm, which forms a hinge that can be elastically pre-tensioned, and wherein the first circular recess is provided in the rear wall of the diaphragm in a transition area between the flat base section of the pump chamber and the conically widening pump chamber wall and wherein a single second circularly extending recess is provided in the rear wall of the diaphragm, which second recess is concentric to the first recess and in an area over the side edge of the pump chamber.