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:
Mar. 15, 1977
Filed:
Apr. 07, 1975
Merlin D Spitsbergen, Rochester, MI (US);
James G Hughes, Rochester, MI (US);
Computer Peripherals, Inc., Rochester, MI (US);
Abstract
A ribbon drive and motor control system in which the instantaneous speed and torque output of a pair of motors are controlled interdependently to bidirectionally transfer ribbon or other web material between a pair of storage reels mechanically coupled to the motors at a uniform ribbon velocity and tension. The motors are electrically excited in series to rotate in the same direction with the back electromotive force of one motor being used to vary the instantaneous excitation voltage applied to the other motor, while drag from said other motor is imparted to the ribbon to control the speed of the first motor. Compensation for variation of the radii of ribbon on the reels during operation is accomplished automatically by variation of motor torque and velocity to minimize variation in ribbon tension and ribbon velocity. A bridge switch actuated by signals initiated by electrical contacts near the ends of the ribbon causes the motors to reverse direction. The system results in longer ribbon life, improved tracking and increased speed capability in an impact printer without complex servo controls.