Hydraulic control means with magnetic flow sensing spool

Claim 2

In a hydraulic actuator comprising a piston in a cylinder and a hydraulic pump driven by an electric motor, said pump being connected to opposite ends of said cylinder by a pair of hydraulic lines through a reversing valve to reciprocate said piston, a bi-directional hydraulic flow and pressure responsive controller for controlling said valve and motor, said controller being connected in one of said lines and comprising a cylindrical housing having line connecting fittings at opposite ends thereof, a slidable magnetic spool in said housing, an axially extending passageway formed in said spool whereby pressurized liquid entering either one of said fittings is adapted to simultaneously pass through said spool and drive said spool towards the other fitting, a pair of springs acting at opposite ends of said spool to center position the same in said housing, and a pair of magnetically responsive switches mounted on said housing at opposite ends thereof, said switches being electrically connected to said reversing valve and motor and being responsive to movement of said spool from its center position towards either of said fittings.

Claim 3

In a waste compactor comprising a piston in a hydraulic cylinder and a hydraulic pump for driving the same, an electric motor for driving said pump, a hydraulic reservoir and a pair of hydraulic lines extendinG to opposite ends of said cylinder, a four-way reversing valve connected to said pump, reservoir and lines for reciprocating said piston, a hydraulic flow and pressure responsive controller in one of said lines for controlling said valve and motor, said controller comprising a cylindrical housing having the line connecting fittings at opposite ends thereof, a slidable magnetic spool in said housing, an axially extending passageway formed in said spool whereby pressurized liquid entering either one of said fittings is adapted to simultaneously pass through said spool and drive said spool towards the other fitting, a pair of magnetically responsive switches mounted on said housing at opposite ends thereof and being responsive to movement of said spool from its center position towards either of said fittings, said spool being spring biased to a central neutral position in said housing away from said switches whereby said controller is also responsive to no or low hydraulic flow and pressure, said switches being electrically connected to a pair of relay coils, one for reversing said valve and operating said motor, and the other for operating said motor, whereby successive positioning of said spool at opposite ends of said housing automatically reciprocates said piston and central neutral positioning of said spool in said housing automatically stops said piston.

Claim 4

In a waste compactor comprising a piston in a hydraulic cylinder and a hydraulic pump for driving the same, an electric motor for driving said pump, a hydraulic reservoir and a pair of hydraulic lines extendinG to opposite ends of said cylinder, a four-way reversing valve connected to said pump, reservoir and lines for reciprocating said piston, a hydraulic flow and pressure responsive controller in one of said lines for controlling said valve and motor, said controller comprising a cylindrical housing having the line connecting fittings at opposite ends thereof, a slidable magnetic spool in said housing, an axially extending passageway formed in said spool whereby pressurized liquid entering either one of said fittings is adapted to simultaneously pass through said spool and drive said spool towards the other fitting, a pair of magnetically responsive switches mounted on said housing at opposite ends thereof and being responsive to movement of said spool from its center position towards either of said fittings, said spool being spring biased to a central neutral position in said housing away from said switches whereby said controller is also responsive to no or low hydraulic flow and pressure, said switches being electrically connected to a pair of relay coils, one for reversing said valve and operating said motor, and the other for operating said motor, whereby successive positioning of said spool at opposite ends of said housing automatically reciprocates said piston and central neutral positioning of said spool in said housing automatically stops said piston.