US 7,490,421 B1
	Method and construction machine for producing ground surfaces
Georg Pletzer, Berlin (Germany); Joachim Waegner, Waltrop (Germany); and Heinrich Lackenberg, Selm (Germany)
Assigned to Herrn Georg Pletzer, Bochum (Germany)
Appl. No. 10/49,925 PCT Filed Jul. 13, 2000, PCT No. PCT/EP00/06660 § 371(c)(1), (2), (4) Date Sep. 21, 2004, PCT Pub. No. WO01/14648, PCT Pub. Date Mar. 01, 2001.
Claims priority of application No. 199 39 796 (DE), filed on Aug. 21, 1999.
Int. Cl. E02F 5/00 (2006.01); A01B 63/112 (2006.01)

U.S. Cl. 37—382  [172/4.5; 172/10; 701/50]

11 Claims

1. A method for producing ground surfaces by means of a construction machine, in particular a hydraulic excavator with an excavator comprised of one single or a multitude of components including a shovel applicable to the surface of the ground, and a lifting cylinder for lifting and lowering the excavator equipment; whereby the lifting cylinder of the excavator equipment is actively connected with at least one work pump via a control device actuated by the operator; and whereby the lifting cylinder is lifted, lowered or blocked depending on the switching position of the control device; wherein for compensating the weight of the excavator equipment and for adjusting an approximately constant pressure of application of the shovel to the surface of the ground as the excavator equipment is moving and working, the lifting side of the lifting cylinder, upon actuation of an actuating element, is automatically acted upon by an adjustable compensation pressure by supplying or evacuating a hydraulic medium, wherein the admission of the compensation pressure is terminated upon actuation of the control device by the operator.