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. 09, 2003
Filed:
May. 21, 2002
Hiroyuki Takahashi, Hitachinaka, JP;
Kenichi Tetsu, Hitachinaka, JP;
Toshiyuki Suzuki, Hitachinaka, JP;
Hitachi Koki Co., Ltd., Tokyo, JP;
Abstract
Each of the rotors has a plurality of identification marks arranged on a circumference defined by the rotation axis on a surface thereof with angular intervals which are determined for each of the different rotors. The identification marks are detected with an identification mark detector such as a magnet detector. The rotational speed of the rotation axis is detected. The angular intervals are detected to identify the attached rotor. The rotating speeds are measured from the pulses at first detection of one of the identification marks and second detection of the one of identification marks after one rotation of the rotation axis. The time intervals of the identification marks between the first and second detection are measured. The angular intervals are calculated by integrating the measured rotating speeds with the time intervals, respectively.