Patent ID: 7273358

Claim:
An air pump comprising: a body ( 10 ) having a housing ( 11 ) being composed of a first semi-housing ( 111 ) and a second semi-housing ( 112 ), a chamber ( 12 ) defined between the two semi-housings ( 111 , 112 ), an opening ( 14 ) defined at a top of the housing ( 11 ) and in communication with the chamber ( 12 ), multiple threaded holes ( 16 ) defined around the opening ( 14 ) and formed longitudinally in the top of the housing ( 11 ), a sleeve ( 17 ) with a passage ( 171 ) secured axially in the opening ( 14 ) and having a rim ( 172 ) formed radially on a top end of the sleeve ( 17 ) and multiple apertures ( 175 ) defined longitudinally through the rim ( 172 ) and aligned respectively with the threaded holes ( 16 ), an air inlet ( 18 ) defined at an outer surface of the first semi-housing ( 111 ), and an axle hole ( 19 ) defined through the first semi-housing ( 111 ) and coaxial with the air inlet ( 18 ); a motor ( 30 ) mounted on the first semi-housing ( 111 ) of the body ( 10 ), the motor ( 30 ) having an output axle ( 31 ) rotatably extending through the axle hole ( 19 ); a gear assembly ( 40 ) received in the chamber ( 12 ), the gear assembly ( 40 ) having a first gear ( 41 ) installed on the output axle ( 31 ) of the motor ( 30 ), and a second gear ( 42 ) rotatably mounted on the first semi-housing ( 111 ) and engaged with the first gear ( 41 ); a piston ( 50 ) having a movable block ( 51 ) received in and moving axially in the passage ( 171 ) of the sleeve ( 17 ), a linkage ( 52 ) formed beneath the movable block ( 51 ) and eccentrically connected to the second gear ( 42 ) by a pin ( 54 ), a first one-way sheet ( 53 ) provided in the movable block ( 51 ) to prevent air from flowing back into the chamber ( 12 ); and a discharge valve ( 60 ) mounted on the top of the housing ( 11 ), the discharge valve ( 60 ) having a nozzle ( 62 ) formed on an outer periphery of the discharge valve ( 60 ) and in communication with the sleeve ( 17 ) by a second one-way sheet ( 61 ) provided at a bottom of the valve ( 60 ) to prevent air from flowing back into the sleeve ( 17 ).