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:
Mar. 24, 2009
Filed:
Sep. 10, 2003
Michael Stirm, Oberursel, DE;
Norbert Hahn, Limbach, DE;
Martin Lauterwald, Huenstetten, DE;
Achim Jung, Hofheim-Marxheim, DE;
Stefan D. Gensmann, Frucht, DE;
Robert Alan Usselman, Forest Hill, MD (US);
Robert Bradus, Bel Air, MD (US);
Michael Stirm, Oberursel, DE;
Norbert Hahn, Limbach, DE;
Martin Lauterwald, Huenstetten, DE;
Achim Jung, Hofheim-Marxheim, DE;
Stefan D. Gensmann, Frucht, DE;
Robert Alan Usselman, Forest Hill, MD (US);
Robert Bradus, Bel Air, MD (US);
Black & Decker Inc., Newark, DE (US);
Abstract
A hand held motor driven electrically powered tool, in particular a rotary hammer, comprising a spindle () for rotatingly driving a tool or bit (), a spindle rotary drive train () for rotatingly driving the spindle () and an arrangement for detecting blocking events (). Blocking events occur when the tool or bit of the tool become rotationally fixed in the material being bored in which case the rotary drive on the spindle from the motor causes the tool housing to rotate in a user's grip. According to a first aspect of the invention an overload clutch () is provided in the spindle rotary drive train for transmitting rotary drive to the spindle below a predetermined torque and slipping above the predetermined torque arranged such that the overload clutch cuts off rotary drive to the spindle, for example by reducing the predetermined torque at which the overload clutch () slips when a blocking event is detected so as to cut off rotary drive to the spindle in response to a blocking event being detected. According to a second aspect of the invention there is provided a mode change mechanism () for selectively disengaging a clutch () so as to cut off the rotary drive to the spindle () and the clutch is disengaged when a blocking event is detected so as to cut off rotary drive to the spindle in response to a blocking event being detected.