Patent ID: 7527595

Claim:
A pump, comprising: a pump case composed of an upper case, an intermediate case and a lower case, a lower face of the upper case is formed with an annular groove which communicates with an exhaust port; a diaphragm body provided in the pump case between the upper case and the intermediate case so as to define a pump chamber communicated with an external member having an air chamber; and an exhaust valve, comprising: a valve body, formed as a hollowed cylindrical projection and integrated with diaphragm body and having a slit through which air in the pump chamber is exhausted, a closed upper end face of the valve body being brought into contact with a bottom face of the annular groove; and a solid adjuster screw, screwed into the intermediate pump case, an actuating face of the adjuster screw being abutted against a part of a lower face of a periphery of a lower opening of the valve body to deform the valve body to adjust an opening amount of the slit by a screwed amount of the adjuster screw, thereby adjusting an exhausting rate of the air in the pump chamber, wherein the lower opening of the valve body is oval in shape, a first portion of the lower opening being smaller than an outer diameter of the actuating face of the adjuster screw and a second portion of the lower opening situated outside the actuating face of the adjuster screw, the intermediate pump case being formed with a ventilation hole communicated with second portion of the lower opening and the pump chamber to allow the air exhausted from the slit to pass through.