The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 11, 1989
Filed:
Dec. 28, 1982
Rolf Kordak, Lohr, DE;
Mannesmann Rexroth GmbH, Lohr, DE;
Abstract
A hydraulic drive system to actuate the piston of a cylinder unit comprises a first hydrostatic machine having variable displacement, a second hydrostatic machine mechanically coupled to said first machine and operating as a signal generator either in a pump mode or a motor mode, and a third hydrostatic machine of fixed displacement mechanically coupled to said first machine, which third machine is hydraulically connected to said cylinder unit. In response to zero speed or rotation of the drive system the piston of the cylinder unit may be stopped in any position, or, respectively, raised or lowered. The variable displacement machine may operate as a pump and as a generator in which latter case energy is recovered in lowering a load.