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. 16, 1988
Filed:
Oct. 20, 1986
Anton Neumaier, Furstenfeldbruck, DE;
Hilti Aktiengesellschaft, , LI;
Abstract
A hammer drill can be switched between combined rotary and impact operation and impact operation. An electropneumatic mechanism provides the impact force and includes a guide cylinder with a beveled gear wheel extending around the outside surface of the cylinder. The gear wheel is driven by a drive wheel. A coupling sleeve is mounted on the guide cylinder for rotation with it and is axially displaceable relative to the cylinder between a first position in meshed engagement with the gear wheel and a second position displaced out of meshed engagement. A switching device moves the coupling sleeve between the two positions. In the first position, the coupling sleeve rotates the guide cylinder, while in the second position the guide cylinder is locked against rotation. The switching device includes a control cam engaged within a groove extending in the circumferential direction of the outside surface of the guide cylinder. In the second position of the coupling sleeve, the control cam is moved inwardly relative to the cylinder into one of a plurality of detent openings formed in the base of the groove for locking the guide cylinder so that it does not perform any rotary movement.