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. 24, 1981
Filed:
Jun. 25, 1979
Emanuel Logan, Jr, Silver Spring, MD (US);
Reliable Security Systems, Inc., Columbus, OH (US);
Reliable Security Systems, Inc., Columbus, OH (US);
Abstract
A magnetic emergency exit door locking system includes a magnetic lock with an armature securred to an emergency exit door and a coil to the lintel of the door. The coil is connected to a power supply and keeps the door locked as long as the power supply applies current thereto. A drop-out relay is disposed in the line between the power supply and coil to interrupt current to the coil when operated. The drop-out relay is operated by a switch which is tripped upon pushing the push-bar on the door. In order to prevent immediate opening of the door upon pressing the push-bar, a timer is disposed between the switch and the drop-out relay to delay unlocking of the door for a selected interval having a duration of, perhaps, fifteen (15) to forty (40) seconds. An alarm sounds during this interval to give notice that someone is trying to open the door.