Control systems for operating jack units

Claim 3

A control system equipped with at least one jack means having a cylinder and a fluid-operated piston therein for performing load displacements through the piston rod by means of a fluid action delivered by a pump; comprising conduit means spacing the cylinder of said jack means from said pump a predetermined relatively large distance from each other and operatively interconnecting said cylinder with said pump, first control means positioned adjacent one end of said cylinder and in communication therewith, first spring means cooperable with said first control means to normally close the access to said cylinder via said conduit means, second control means slidably arranged in said one conduit means, third control means positioned remote from said first and second control means and in the proximity of said pump, said third control means including spaced apart ball elements structured for displacement together in tandem and relative to said conduit means, channel means establishing communication between said pump and at least one of said conduit means, and operable means for actuating one of said ball elements of said third control means for placement of said one ball element to establish intercommunication between said conduit means, whereas upon displacement of said other ball element by said operable means said one ball element establishes connection with said other conduit means, said second control means being cooperable with said first control means so as to influence the position of the latter in order to maintain the same either closed under spring action or to change said position for discharge of fluid from said cylinder throuGh one said conduit means.

Claim 4

A control system equipped with at least one jack means having a cylinder and a fluid-operated piston therein for performing load displacements through the piston rod by means of a fluid action delivered by a pump; comprising conduit means spacing the cylinder of said jack means from said pump a predetermined relatively large distance from each other and operatively interconnecting said cylinder with said pump, first control means positioned adjacent one end of said cylinder and in communication therewith, first spring means cooperable with said first control means to normally close the access to said cylinder via said conduit means, second control means slidably arranged in said one conduit means, third control means positioned remote from said first and second control means and in the proximity of said pump, said third control means including spaced apart ball elements structured for displacement together in tandem and relative to said conduit means, channel means establishing communication between said pump and at least one of said conduit means, and operable means for actuating one of said ball elements of said third control means for placement of said one ball element to establish intercommunication between said conduit means, whereas upon displacement of said other ball element by said operable means said one ball element establishes connection with said other conduit means, said second control means being cooperable with said first control means so as to influence the position of the latter in order to maintain the same either closed under spring action or to change said position for discharge of fluid from said cylinder throuGh one said conduit means.

Claim 5

A control system according to claim 2, said operable means being actuatable on either of said ball elements to displace same for establishing fluid communication from said pump to the respective cylinders of said jack means via said first control means and also via second control means, both said first and second control means being differentially structured for operation and being, respectively, positioned near opposite ends of said jack means for supply fluid under pressure from said pump to said jack means via said conduit means and for discharging said fluid from said cylinders of said jack means under predetermined operational conditions to a reservoir connected to said operable means.

Claim 6

A control system according to claim 3, wherein both said differential control means are provided with needle valve means, and spring means supporting both said control needle valve means during operation.

Claim 7

A hydraulic system comprising a pump, a fluid actuated jack having a cylinder and a first piston reciprocably received therein defining a working chamber, a reservoir, passageway means communicating said chamber with said pump and with said pump and with said reservoir, control valve means in said passageway means, said control valve means having a first position wherein said chamber is communicated to said pump and is pressurized upon actuation of said pump, and a second position wherein communication between said pump and said chamber is closed and the chamber is communicated to said reservoir to exhaust the fluid therein, a one-way check valve, means biasing said check valve to a normally closed position, in said passageway means between said chamber and said control valve means, said check valve being pushed to the open position by pressurized fluid when said control valve is in the first position and said pump is actuated, and a check valve actuating means responsive to pressure from said pump to push said check valve off its seat when said control valve means is in said second position, said check valve actuating means comprising a second passageway means leading from said pump to said first passageway means and intersecting therewith adjacent said check valve, an actuating piston slidably received in said second passageway means, said actuating piston having differential working surfaces on opposite ends thereof, one of said surfaces being exposed to said second passageway means, and the other of said surfaces being exposed to said first passageway means and being of an area greater than that of said one of said surfaces, whereby when said control valve means is in said first position, fluid pressure in said first and second passageway means will act on said working surfaces, and because of said differential surfaces, said actuating piston will be urged away from said check valve.

Claim 8

A hydraulic system comprising a pump, a fluid actuated jack having a cylinder and a first piston reciprocably received therein defining a working chamber, a reservoir, passageway means communicating said chamber with said pump and with said pump and with said reservoir, control valve means in said passageway means, said control valve means having a first position wherein said chamber is communicated to said pump and is pressurized upon actuation of said pump, and a second position wherein communication between said pump and said chamber is closed and the chamber is communicated to said reservoir to exhaust the fluid therein, a one-way check valve, means biasing said check valve to a normally closed position, in said passageway means between said chamber and said control valve means, said check valve being pushed to the open position by pressurized fluid when said control valve is in the first position and said pump is actuated, and a check valve actuating means responsive to pressure from said pump to push said check valve off its seat when said control valve means is in said second position, said check valve actuating means comprising a second passageway means leading from said pump to said first passageway means and intersecting therewith adjacent said check valve, an actuating piston slidably received in said second passageway means, said actuating piston having differential working surfaces on opposite ends thereof, one of said surfaces being exposed to said second passageway means, and the other of said surfaces being exposed to said first passageway means and being of an area greater than that of said one of said surfaces, whereby when said control valve means is in said first position, fluid pressure in said first and second passageway means will act on said working surfaces, and because of said differential surfaces, said actuating piston will be urged away from said check valve.

Claim 9

The system of claim 5 wherein said jack is a double-acting jack and including a second chamber on the side of said first piston opposite said first chamber, and including third passageway means between said second chamber and said second passageway means.

Claim 10

The system of claim 5 wherein said pump is hand operated and includes a housing, a pumping chamber having inlet and outlet means, a pumping piston reciprocably received in said chamber, and handle means for reciprocating said pumping piston.

Claim 11

The system of claim 5 wherein said control valve includes a pair of valve seats, one disposed between the reservoir and said chamber and the other disposed between the pump and said chamber, a pair of interconnected valve heads one of which seats on said one seat when said control valve means is in the second position, and the other of which seats on said other seats when the control valve means is in the second position, and means for alternately seating said valve heads on said seats.