Diaphragm pump

In a diaphragm pump having a housing, a diaphragm peripherally mounted in said housing to define a pump chamber, and inlet and outlet means communicating with said pump chamber, the improvement comprising:

• a support plate forming part of the housing having a hollow stud which projects into a second chamber of the housing defined in part by the diaphragm,
• a cam follower disposed in the second chamber and secured to a central portion of the diaphragm, said cam follower having a stem reciprocably and non-rotatably mounted in the hollow stud and a pair of round ended studs radially spaced from the stem and diametrically opposite each other,
• a cam-gear disposed in the second chamber and rotatably mounted on the hollow stud on an axis concentric with the cam follower and diaphragm,
• said cam-gear having an annular sinusoidal cam face engaging said pair of round ended studs to reciprocate the diaphragm as the cam-gear is rotated,
• compression spring means disposed in the pump chamber engaging the diaphragm to expand the pump chamber and maintain the pair of round ended studs in engagement with the cam face, and
• means on the support plate for mounting a motor and receiving the motor output shaft and an attached drive pinion in the second chamber for driving the cam-gear at a reduced speed.