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:
Sep. 20, 2005
Filed:
Oct. 13, 2004
Kozo Kawai, Neyagawa, JP;
Yoshinori Sainomoto, Sanda, JP;
Tatsuhiko Matsumoto, Habikino, JP;
Tadashi Arimura, Kyoto, JP;
Toshiharu Ohashi, Sakata-gun, JP;
Hiroshi Miyazaki, Hikone, JP;
Hidenori Shimizu, Hikone, JP;
Fumiaki Sawano, Hikone, JP;
Kozo Kawai, Neyagawa, JP;
Yoshinori Sainomoto, Sanda, JP;
Tatsuhiko Matsumoto, Habikino, JP;
Tadashi Arimura, Kyoto, JP;
Toshiharu Ohashi, Sakata-gun, JP;
Hiroshi Miyazaki, Hikone, JP;
Hidenori Shimizu, Hikone, JP;
Fumiaki Sawano, Hikone, JP;
Matsushita Electric Works, Ltd., Osaka, JP;
Abstract
In a power impact tool for fastening a fastening member, a torque for fastening the fastening member can be estimated without using a high-resolution sensor and a high-speed processor. The power impact tool comprises a rotation speed sensor for sensing a rotation speed of a driving shaft of a motor with using a rotation angle of the driving shaft, a rotation angle sensor for sensing a rotation angle of an output shaft to which a bit is fitted in a term between an impact of a hammer to next impact of the hammer, a torque estimator for calculating an impact energy with using an average rotation speed of the driving shaft and for calculating a value of estimated torque for fastening the fastening member which is given as a division of the impact energy by the rotation angle of the output shaft, a torque setter for setting a reference value of torque to be compared, and a controller for stopping the driving of the motor when the value of the estimated torque becomes equal to or larger than a predetermined reference value set by the torque setter.