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:
Jun. 18, 2002
Filed:
Feb. 07, 2001
Heinrich Dueckinghaus, Bieldefeld, DE;
Dirk Schlichting, Paderborn-Dahl, DE;
Caterpillar S.A.R.L., Geneva, CH;
Abstract
The present invention is concerned with a work machine having a telescopic arm coupled to the front thereof. This arm is used for seating various sorts of frontal attachments and is raised and lowered by means of a hydraulic piston-cylinder unit. Now in order to ensure that an installed frontal attachment always rests on the ground with a pre-selected force, use is made of a pilot controlled seat valve and an adjustable pressure regulating valve which ensure that a constant pressure is maintained in the cylinder chamber formed below the base of the piston in the piston-cylinder unit when a constant supply of oil is fed to this part of the cylinder chamber. In consequence, this means that the installed frontal attachment always rests on the ground with one and the same force independently of whether the ground is flat or uneven. The frontal attachment thus precisely copies the contour of the ground at all times.