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, 1987
Filed:
Feb. 12, 1985
Emanuel L Logan, Columbia, MD (US);
Michael A Kelly, Felton, PA (US);
Bruce G Beigel, Seven Valleys, PA (US);
Reliable Security Systems, Inc., Cockeysville, MD (US);
Abstract
A door mounted in a door frame is held closed by an electromagnet mounted on the door frame which magnet attracts an armature mounted on the door. A switch is mounted adjacent to the electromagnet and is operated by a switch operator mounted on the door. The switch provides a signal indicating that an attempt is being made to open the door, which signal may be used to sound an alarm or start a time delay release. A pair of contacts are also mounted adjacent to the electromagnet and are bridged by the armature to indicate when the armature is properly held by the electromagnet.