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. 10, 1983
Filed:
Jul. 08, 1981
Shigeru Matsuoka, Hitachi, JP;
Takeshi Tokunaga, Hitachi, JP;
Seiji Yonekura, Hitachi, JP;
Koji Yamauchi, Hitachi, JP;
Mitsuo Suzuki, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A motor for operating the door is controlled for forward and reverse rotations and stoppage by a control circuit responsive to an operation command signal, an upper-lower limit signal, an obstruction detection signal and a maximum drive time over signal, thus controlling the door stepwise for opening, stoppage, closing, stoppage and opening in that order. Upon generation of an obstruction detection signal or a maximum drive time over signal during the closing operation, the control circuit controls the motor in a manner to open the door for a certain period of time, and subsequently upon application of an operation command signal, the control circuit is set in a manner to open the door again.