| 主权项 |
1. An apparatus for the return of grease under pressure within a manually operated grease gun to the grease gun reservoir, the apparatus comprising:
a lever; a grease gun reservoir; a grease pump connected to the grease gun reservoir and to the lever, the grease pump manually operated by the lever to manually pump grease from the grease reservoir to an outlet of the grease pump; a delivery line, the delivery line being a flexible hose; a three-port valve body, wherein the three-port valve body includes i) a pressure inlet port connected to the outlet of the grease pump, ii) a delivery port connected to discharge the grease to an inlet of the flexible hose of the delivery line and iii) a pressure relief port located between the pressure inlet port and the delivery port, wherein the pressure relief port includes a one way flow control valve mounted therein and an activation means for the one way flow control valve, the activation means connected to the lever, wherein the one way flow control valve is maintained in a closed position by pressure of the grease within the three-port valve body and is manually activatable, by the activation means, to be opened when required; an elongated passage that links the relief port to the grease gun reservoir, the elongated passage providing a path for the grease under pressure to be returned to the grease gun reservoir on activation of the one way flow control valve, thereby allowing a pressure in the delivery line to reduce to atmospheric pressure, wherein the lever manually activates the activation means to displace the one way flow control valve from the closed position to thereby open the relief port to the grease gun reservoir and return the grease, under pressure, from the three-port valve body to the grease gun reservoir and allow the pressure in the delivery line to reduce to the atmospheric pressure, wherein the one way flow control valve remains effectively closed by the pressure of the grease within the valve body during operation, wherein the activation means comprises an activation rod extending into the elongated passage, the lever manually activating the activation rod to displace the one way flow control valve from the closed position, into three-port valve body, to thereby open the relief port to the grease gun reservoir and return the grease, under pressure, from the three-port valve body to the grease gun reservoir and allow the pressure in the delivery line to reduce to the atmospheric pressure, and wherein the activation rod comprises a stepped shaft, a smaller diameter end thereof being slidably located within the elongated passage that connects the three port valve body to the grease reservoir. |
