Portable bicycle air pump with a pressure-testing device for pumping up a bicycle inner tube through lightweight pump valves displays maximum allowable inner tube pressure.

摘要

A pressure-testing device (15) is an integral component in a pump rod (4) within a pump rod grip (6). Flow calibration between a bicycle tube, a pressurized space (19) and a pressure-measuring rod (8) occurs through a pump rod bore hole (5). A measuring pin (13) with a pressure value scale is extended in proportion to pressure in a pressure-testing spring (9) by means of the pressure-measuring rod.