Patent ID: 7976290

Claim:
An air pump comprising: a bracket formed integrally from a single piece of sheet metal having a uniform and even thickness, and having a backplate formed from the sheet metal and having two opposite sides; two side plates formed from the sheet metal and being formed respectively on and protruding respectively forward from the sides of the backplate and each side plate having a top edge; and two top plates formed from the sheet metal and being formed respectively on and protruding respectively inward from the top edges of the side plates and facing each other at an interval, wherein each top plate has an inside edge and a curved positioning recess defined in the inside edge, the curved positioning recesses of the top plates being located opposite to each other; a motor mounted directly on the bracket and having a front end and a shaft mounted rotatably on the front end of the motor; a transmission device mounted directly on the bracket and connected to the shaft on the motor; and a pneumatic cylinder assembly mounted directly on the bracket, connected to the transmission device and having a cylinder housing mounted on the top plates on the bracket, located in the interval between the top plates and having an open top, an open bottom and a cavity defined in the cylinder housing and communicating with the open top and the open bottom and having an inner surface, wherein the cylinder housing has a cylindrical outer surface engaging with the curved positioning recesses of the top plates of the bracket; an outlet valve mounted on the open top of the housing and having an outlet tube; and a piston mounted movably in the cavity in the cylinder housing through the open bottom and connected pivotally to the transmission device.