Grease gun with overpressure relief valve and indicator

摘要

A battery powered grease gun has an overpressure relief valve for returning grease to the grease barrel mounted to the grease gun head when a plugged zerk prevents grease from exiting the output port. The grease gun head includes a small relief passageway joined to the output port of the grease gun head which is closed by an adjustable check valve. When the pressure of grease in the output port rises above a preselected pressure, grease will pass through the relief passageway to the grease barrel or, if so equipped, to the grease supply adapter which is mounted to the grease gun head. The grease gun head is additionally provided with a sampling duct which is joined to the output port. The sampling duct couples the output port to another port in which a pressure gauge or a pressure transducer may be installed. The pressure of grease in the output port may be displayed on the pressure gauge or on a display coupled to the transducer.