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:
Nov. 18, 2008
Filed:
Nov. 30, 2004
John Robert Christian Friberg, Nacka, SE;
John Robert Christian Friberg, Nacka, SE;
Atlas Copco Tools AB, Nacka, SE;
Abstract
In an impulse wrench there is provided an impulse unit with a motor driven inertia drive member, and a movement detecting device arranged to detect an angular movement of the inertia drive member. The movement detecting device includes a rotating disc rigidly connected to and co-rotating with the inertia drive member. The impulse wrench also includes a sensing device including four Hall-element type sensors, and the disc has a rim portion which is magnetised to provide a number of magnetic poles for activating the sensors at rotation of the inertia drive member. The sensors are arranged in pairs such that the delivered signals from the sensors in each pair has a relative phase lag of 180 degrees, and the sensors of one of the pairs are arranged to deliver signals with a phase lag of 90 degrees relative to the sensor signals from the other pair.