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:
Oct. 30, 1979
Filed:
Jun. 03, 1977
Koji Nishida, Nagoya, JP;
Taneichi Kawai, Anjo, JP;
Shigemitsu Hamajima, Obu, JP;
Tsuneo Hida, Anjo, JP;
Nobuyosi Nagura, Anjo, JP;
Aisin Seiki Kabushiki Kaisha, Kariya, JP;
Abstract
A speed control device for a sewing machine includes at least means for providing a speed reference voltage signal, means for producing a motor speed voltage signal responsive to an actual speed of the driving motor, and means for comparing the speed reference voltage signal with the motor speed voltage signal to provide a speed difference signal. The speed difference signal is utilized to determine triggering angle of a thyristor means for controlling the motor speed and to maintain the predetermined motor speed irrespective of any variation in the driving torque of the motor, the voltage of the power source and the frequency of the A.C. power source.