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:
Feb. 09, 1993
Filed:
Aug. 15, 1991
Reinhold Schniederjan, D-Neu-Ulm, DE;
Ludwig Wagenseil, Vohringen, DE;
Hydromatik GmbH, , DE;
Abstract
The invention relates to a control and regulating device for a hydrostatic transmission which comprises a reversible hydraulic pump that can be driven by a driving motor, at least one hydraulic motor that is connected via two working lines to the hydraulic pump, and an adjusting device that can be acted on by an adjusting pressure for adjusting the volume and direction of displacement of the hydraulic pump, together with a displacement-direction control valve for controlling and regulating the action of the adjusting pressure on the adjusting device, can be actuated as desired both by a control signal that is proportional to the speed of rotation of the driving motor and predetermines the direction of displacement of the hydraulic pump and by a working pressure signal that is proportional to the working pressure in the working line then carrying the high pressure. To enable a load that has been decelerated to a standstill both to be maintained at a standstill and also to be shunted without mechanical braking, even when actuation of the displacement-direction control valve by the control signal is interrupted, the invention provides for switching over the working pressure signal applied to the displacement-direction control valve in the absence of the control signal.