Hydraulic unit
AssigneeKvaerner Pulping AB
InventorsAxel Stig Lam.ang.s, Allan Sven Jonsson
Life of this patent
Estimating the term…
Abstract
The invention relates to a hydraulic unit for feeding an object at a desired feed speed a distance in a given feed direction during a working stroke and, in a return stroke, bringing the object back to the initial position at a considerably greater return speed, comprising a double-acting working cylinder (1) with a piston (16), the piston rod (17) of which is connected to the object which is to be moved, and a receiver cylinder (2) which is provided with a second piston (28) and designed to be filled with oil from the working cylinder during the return stroke, the first piston (16) and the second piston (28) being interconnected by a rigid connecting member (31) which forces the second piston to follow the movements of the first piston.
Claims23
A hydraulic cylinder for shifting an object a distance at a desired speed in a feed direction, comprising:
- a first cylinder having a movable first piston disposed therein, the first piston being movable in a working stroke from a start position to an end position at a first speed and movable in a return stroke from the end position to the start position at a second speed, the second speed being substantially greater than the first speed;
- a piston rod attached to the first piston;
- a second cylinder having a movable second piston disposed therein, the second cylinder being adapted to be filled with a fluid from the first cylinder during the return stroke;
- and
- a rigid connecting member attached to both the first piston and the second piston so that the second piston is forced to follow any shifting of the first piston.
A hydraulic cylinder assembly, comprising:
- a first cylinder having a movable first piston disposed therein, the first piston being movable from a start position to an end position at a first speed and movable from the end position to the start position at a second speed, the second speed being substantially greater than the first speed;
- a second cylinder having a movable second piston disposed therein;
- a first channel section extending between the first cylinder and the second cylinder;
- a first passage member having one end attached to the first channel section and an opposite end attached to the second cylinder;
- a main valve in operative engagement with the first passage member, the main valve being movable between an opened position to permit a fluid flow between the first channel section and the second cylinder and a closed position to prevent any fluid flow between the first channel section and the second cylinder;
- a rigid connecting member attached to both the first piston and the second piston so that the second piston is forced to follow any movement of the first piston, the connecting member extending from the first cylinder through the first channel section and into the second cylinder;
- and
- a gasket member disposed in the first channel section to sealingly receive the connecting member.
A method for moving fluid from a first cylinder to a second cylinder, comprising:
- providing a first cylinder having a movable first piston disposed therein, a second cylinder having a movable second piston disposed therein, a rigid connecting member attached to both the first piston and the second piston so that the second piston is forced to follow any shifting of the first piston, a transfer conduit extending from a lower portion to an upper portion of the first cylinder, an adjustment valve is in operative engagement with the transfer conduit, a return line extending from the second cylinder to a hydraulic tank, and a cooling apparatus and a filter mechanism in operative with the return line;
- moving the first piston and the second piston downwardly from an upper position at a first speed;
- adjusting the first speed of the downwardly moving first piston by modifying the adjustment valve;
- the second piston pressing out a return fluid from the second cylinder into the return line;
- cooling the return fluid in the return line;
- filtering the return fluid in the return line;
- and
- conveying the return fluid from the return line into the hydraulic tank.
Dependencies are inferred from the claim text.