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:
Aug. 02, 2005
Filed:
May. 08, 2002
Rudolf Berger, Grünwald, DE;
Wolfgang Schmid, München, DE;
Mirko Lysek, München, DE;
Thomas Schmidbauer, München, DE;
Rudolf Berger, Grünwald, DE;
Wolfgang Schmid, München, DE;
Mirko Lysek, München, DE;
Thomas Schmidbauer, München, DE;
Wacker Construction Equipment AG, Munich, DE;
Abstract
The invention relates to a demolition hammer and/or hammer drill comprising a percussion generating device having a percussion piston moving axially back and forth. In a main percussion mode, the percussion piston impinges upon a tool which can move along a limited axial path straight into a main percussion direction. In a free percussion mode, the percussion piston indirectly impinges upon a percussion changing device, and by means thereof upon the tool, in a free percussion direction opposite to the main percussion direction. The impact surface of a tool shaft and the impact surface of a free percussion ram are placed opposite an impact surface of the percussion piston in such a way that the free percussion ram is removed from the effective area of the percussion piston by a return spring in the main percussion position. Under the effect of the return spring, the percussion ram is simultaneously supported on a gear member of the percussion changing device, which projects with an extension into the motion path of a stop surface provided in the tool. The stop surface reaches the extension when it has moved away from the effective area of the percussion piston in an idle running state of the tool shaft. If the movement of the tool is continued, the stop surface impinges upon the gear member against the effect of the return spring and relocates the free percussion ram in the effective area of the percussion piston by overcoming the spring force.