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:
Nov. 15, 1977
Filed:
Oct. 08, 1976
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., , JA;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E05F / ; B66B / ;
U.S. Cl.
CPC ...
49 28 ; 49363 ; 187 / ;
Abstract
A protection system for an automatically openable and closable door is provided in which an increase in the driving force produced when the door encounters with a blocking force in the opening operation as caused by some obstacles is detected to stop or reverse the door opening operation, thereby to suppress or reduce any possible accidents.