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. 19, 1982
Filed:
May. 09, 1980
Emanuel L Logan, Arlington, VA (US);
Reliable Security Systems, Inc., Cockeysville, MD (US);
Abstract
In order to secure an emergency exit door against unauthorized opening from the inside, a retrofit delay mechanism is attached to the door frame. The delay mechanism includes a retractable bolt which projects behind a strike mounted on the door. A piston is attached to the bolt and a hydraulic circuit is connected to the piston. The hydraulic circuit includes a throttle and a normally open valve. The normally open valve is held closed by a solenoid. Upon attempting to open the door, fluid in the hydraulic circuit is throttled slowing down retraction of the bolt and delaying opening of the door. The solenoid which releases the normally open valve is connected to a timing circuit which de-energizes the solenoid after a predetermined time interval thus providing a redundant delay arrangement. Smoke detectors, fire pull-boxes and a remote reset switch are also connected to the solenoid via a dropout relay. Upon the occurrence of an emergency situation, the dropout relay de-energizes the solenoid allowing fluid to flow freely in the hydraulic circuit so that the door opens immediately. The retrofit delay mechanism operates in conjunction with existing panic hardware.