Abstract: A portable flexible air pump comprises a connection head, a main body and a flexible body located between the connection head and the main body. The connection head is provided therein with an air duct and is engageable with the air valve of a bicycle tire. The main body is provided therein with an air channel in communication with the air duct of the connection head. The air channel is intended to transmit the compressed air. The flexible body is provided axially with a passageway and is connected at both ends thereof with the connection head and the main body by two pivoting members. The air duct of the connection head is in communication with the air channel of the main body via the passageway of the flexible body. The connecting portion between the flexible body and the connection head and the connecting portion between the flexible body and the main body are made airtight by two leakproof portions.

Abstract: An air pump piston is provided peripherally with a first leakproof ring and a second leakproof ring, which are located respectively and contiguously at both ends of the piston. Located peripherally between the first and the second leakproof rings is a radially disposed air hole. The piston is fastened at the second end thereof with a piston rod such that the air hole of the piston is in communication with an axial passageway of the piston rod. The piston is further provided peripherally between the first leakproof ring and the air hole with at least one first duct disposed radially. The piston is still further provided peripherally with at least one second duct which is disposed radially and located between the second leakproof ring and the air hole. The piston is provided at the first end thereof with an air admitting hole in communication with the first duct. The piston is provided at the second end thereof with an air duct in communication with the second duct.