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:
Dec. 01, 2009
Filed:
Feb. 07, 2007
Brian Nielsen, Viborg, DK;
Ole Ploug, Roedekro, DK;
Chad M. Patterson, Huxley, IA (US);
Sauer-Danfoss Aps, Nordborg, DK;
Abstract
A hydraulic actuator for a hydraulic servomotor () is disclosed. The hydraulic servomotor () is of a kind having at least one defined end position, and has a first chamber () and a second chamber () associated therewith. The actuator is connected to a fluid source () and a fluid drain (). The actuator comprises a first valve () fluidly connected between the fluid source () and the first chamber (), a second valve () fluidly connected between the first chamber () and the fluid drain (), and a third valve () fluidly connected between the fluid source () and the second chamber (). The actuator further comprises a flow channel (), preferably comprising a flow restrictor (), in fluid communication with the second chamber (). The valves () are such that, in the case of a power cut off, they will prevent a fluid flow out of the first chamber (), and a fluid flow out of the second chamber () takes place via the flow channel (). This will cause a servomotor piston member () to move towards the second chamber (), thereby moving the hydraulic servomotor () to an end position.