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:
Nov. 03, 2009
Filed:
Mar. 18, 2005
Stefan Hoefling, Selingenstadt, DE;
Wilhelm Hofmann, Niederdorfelden, DE;
Wolf-michael Petzold, Aichwald, DE;
Stefan Hoefling, Selingenstadt, DE;
Wilhelm Hofmann, Niederdorfelden, DE;
Wolf-Michael Petzold, Aichwald, DE;
Putzmeister Concrete Pumps GmbH, Aichtal, DE;
Abstract
A device and a method for controlling a two-cylinder thick matter pump comprising pistons that are actuated in a push-pull manner by means of a hydraulic reversible pump () and hydraulic drive cylinders controlled by said pump. To ensure a reliable operation of the pump the expected length of the stroke of the pistons () in the drive cylinders (') is measured and recorded, the stroke time of each conveyance stroke is monitored and compared with the expected stroke duration, and the reversible pump () is respectively pivoted, reversing the flow, and/or the pipe switch () is reversed when the stroke time exceeds the expected stroke duration by a pre-determined value.