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. 26, 1988
Filed:
Feb. 24, 1987
Rudolf Brunner, Baldham, DE;
Abstract
The invention relates to a hydromechanical tool or workpiece clamping apptus comprising at least one spring clamping cylinder connected to a release conduit and adapted to be hydraulically operated against a spring force to a release position, a pump connected to said release conduit and operable for a release operation, and a discharge conduit extending from said release conduit to a fluid reservoir and including a discharge control element for discharging the pressurized fluid from said spring clamping cylinder to said reservoir after deenergization of said pump. A known clamping apparatus of this type has a solenoid poppet valve disposed in said discharge conduit and operable to close said discharge conduit for the release operation and to be actuated to a flow-through position and maintained therein for the clamping operation. The solenoid valve is expensive and requires separate control means. In contrast thereto, the invention provides the use of a discharge control element in the form of a simple bypass shutter the flow resistance of which at a constant output flow rate of the pump is greater than the pressure required for overcoming the spring force in a release operation.