Juice extractor with hydraulic control of extraction back pressure

Abstract

A juice extractor includes a mechanism for supporting the exterior of a fruit and separating the peel therefrom, such as upper and lower cups having cutters to cut plugs. A strainer tube is mounted to receive juice and pulp of the fruit. An orifice tube has upper and lower ends and the upper end is moveable within the strainer tube. A reciprocating drive mechanism engages the orifice tube and reciprocates the orifice tube within the strainer tube for generating pressure within the strainer tube to separate juice and pulp within the strainer tube, collect the core material and discharge core out of the lower end of the orifice tube. A valve assembly is positioned at the lower end of the orifice tube. The valve assembly includes a piston having a shaft moveable into an extended position within the orifice tube, and a retracted position where core can be discharged from the lower end of the orifice tube. A predetermined amount of hydraulic pressure is applied onto the piston to extend the shaft into the orifice tube and apply back pressure. The core is discharged from the pressure of the core pulp against the shaft and piston and exceeds the back pressure to retract the shaft. A sensor can also sense when the cylinder shaft is not retracted or moved in a period of machine cycles, indicative that core is not being discharged from the orifice tube. The juice extractor can be shut down after a predetermined period of time after determining that the shaft has not retracted or extended.