Patent attributes
An automatic pressure-relieving apparatus for a suction pump comprises a pipework provided at the cap. A first rod positioned in the pipework has an upper sealing ring arranged around the top periphery thereof, whereby the first rod can detachably seal the upper opening of the pipework. Moreover, the first rod is coupled with a second rod, which is pierced through the lower opening of the pipework and extending into the oil reservoir of the cylinder. The second rod further has a sealing component arranged at the periphery thereof for moving. upward and detachably sealing the lower opening of the pipework. Also, a control device is fastened to the bottom of the second rod so that when the raising oil surface lifts a float of the control device, the float can in turn drive the first and second rods to move upward. Thereby, the upper and lower openings of the pipework are opened and closed respectively, and the pressure in the pump can be automatically released through the opened upper opening.