Compressing diaphragm pump having abnormal pressure preventing features for spray use

A compressing diaphragm pump having abnormal pressure preventing features for spray use comprising:

• a motor having an output shaft;
• an upper hood chassis disposed along a top of the output shaft of said motor, said upper hood chassis comprising a plurality of screw bores formed on an outer rim of the upper hood chassis;
• multiple wobble wheels pivotably connected on said upper hood chassis to serve as the pumping action in a manner so that an axial reciprocal wobbling movement is driven by the output shaft of said motor;
• a diaphragm covering said upper hood chassis;
• a piston valve inset in said diaphragm and having a water discharge port;
• an anti-backflow plastic gasket, three piston slices closely fixed on said piston valve, and an upper hood,
• wherein a top surface of the water discharge port of the piston valve is designed into a downwards camber concave with an orientating hole defined at a center at a lowest point of the downwards camber concave and each bottom surface of three water inlet ports is designed into an upwards camber concave with a center of an orienting hole defined at a highest point of the upwards camber concave;
• wherein the anti-backflow plastic gasket comprises a central orienting stem and is designed into a plano-convex shape which has an upwards arched convex top surface and flat bottom surface, with a center thickness larger than a rim thickness, and both of the anti-backflow plastic gasket and central orientating stem project downwards and are unitarily molded using a same elastic material, said central orienting stem inserted into the orienting hole of the downwards camber concave;
• wherein each of the three piston slices is also designed into a plano-convex shape, where a convex bottom surface arches downwards and the piston slices each have a center thickness larger than a rim thickness;
• and
• wherein a gap is formed between the flat bottom surface of the anti-backflow plastic gasket and the downwards camber concave.