Patent ID: 6227810
Filing Date: 2001-05-08
Classification: B62J,F04B

Abstract:
An air pump structure adapted to be secured to a frame of a bicycle, the bicycle having a bicycle chain coupled to pedals, the air pump comprising:a cylinder adapted to be secured to the bicycle frame having a cylinder bore within which a piston reciprocates; anda crank shaft rotatably supported on the cylinder and drivingly coupled to the piston by a connecting rod and a central axial bore for coupling the crank shaft to the bicycle chain to be driven,wherein said central axial bore is formed in the crank shaft within which a driving shaft is axially movable received, the driving shaft having an outer end extending out of the central bore of the crank shaft to which a chain wheel adapted to be engaged by the bicycle chain is fixed, the driving shaft having an axial length slot and the crank shaft having a radially-extending hole within which a pin is received in such a way to have an end of the pin engaging the slot so as to form a driving engagement between the pin of the crank shaft and the slot of the driving shaft, andwherein the axial length slot allows the chain wheel to be movable relative to the crank shaft between a stowed position and a working position, where the chain wheel is adapted to be engaged by the bicycle chain,so that when the bicycle pedals are actuated to drive the bicycle chain, the bicycle chain forces the crank shaft to rotate and thus making the piston reciprocate within the cylinder bore to pump air through an outlet of the cylinder.