Hydraulic lifting-lowering-system for a working table, a couch or lying furniture or another heavy object

摘要

A hydraulic lifting-lowering-system for a working table, a couch or lying furniture or another heavy object allows the height level or position to be frequently adjusted or changed. The system includes a predetermined amount of hydraulic fluid, a hydraulic fluid accumulator, the fluid pressure of which on the hydraulic fluid side is adjustable, a single acting hydraulic cylinder with two end caps, a piston pressure chamber and a piston rod which, via a piston rod sealing ring, extends sealingly out through the one end cap of the cylinder. The piston pressure chamber is pressure fluid connected to the hydraulic fluid side of the accumulator. The hydraulic cylinder is of the plunger piston type, and the cylindric tube of the hydraulic cylinder is slideably and telescopically mounted in a cylindrical guiding tube, which surrounds the piston rod in its entire length and is rigidly secured to the one end of the piston rod via a cross plate or similar construction part. Thus, a simple, stable and reliable system is achieved without the need for crank handles, and by which new system the force applied from the plunger piston rod will be essentially constant in all positions of the piston rod at a given load, seeing that the operational manual force necessary for height adjustment of the heavy object becomes low.