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:
May. 04, 2010
Filed:
Jun. 22, 2005
Peter Kjellqvist, Mölnbo, SE;
Tobias Lindbäck, Huddinge, SE;
Peter Kjellqvist, Mölnbo, SE;
Tobias Lindbäck, Huddinge, SE;
Atlas Copco Tools AB, Stockholm, SE;
Abstract
The present invention relates to a power-wrench comprising an electrical converter-fed motor having a permanent-magnetized rotor and a stator provided with winding, the motor winding () comprising at least two winding parts, which independently of each other are connected and disconnected by a switch-over device (). According to the invention, a first winding part () may be arranged to control the magnetic field of the motor so that the motor, having the first winding part () connected, is adapted for the threading-down phase of the nut driving and operates with low torque and high number of revolutions adapted to said phase, as well as that a second winding part () may be arranged to control the magnetic field of the motor so that the motor, having the second winding part () connected, is adapted for the final-threading phase of the nut driving and operates with high torque and low number of revolutions adapted to said phase.