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. 13, 2018
Filed:
Apr. 21, 2014
Parker-hannifin Corporation, Cleveland, OH (US);
Ralf Gomm, Charlotte, NC (US);
Christian Josefsson, Sandhult, SE;
Parker-Hannifin Corporation, Cleveland, OH (US);
Abstract
According to one aspect of the invention, a hydraulic system includes a controller connected to an operator interface, a pump operable in a first direction for supplying pressurized fluid, and a load-holding valve connected between the pump and a port for connection to an actuator. The load-holding valve may be controlled by the controller and operative in a first position to allow flow to the actuator to operate the actuator against a load and operative in a second position to block load-induced return flow from the actuator to the pump. The controller may be configured to receive a requested actuator stop, to control the first valve to move to the second position in response to the requested actuator stop, to monitor a first system condition in response to the requested actuator stop, to evaluate the monitored system condition with a prescribed criteria, and to determine whether or not to initiate a back-up control routine based on the evaluation.