Bell Telephone Laboratories

At&t Bell Laboratories

At&t Technologies, Inc.

At&t Information Systems Inc.

American Telephone and Telegraph Company; At&t Information Systems

John G Engstrom

John N McGarvey

Michael P Zambelli

Robert A Till, Jr

John S Campbell

Donald M Genaro

Henry J Mack

Andrew J Baase

Gary Merlin Petaja

Telephone stand

An apparatus for detecting the forced opening of a door. The apparatus comprises a paper sheet with a frangible conductive path thereon. The sheet has holes therein for the passage of a retractable bolt and fasteners, which are used to secure a strike plate to a frame. The sheet is then concealed behind the strike plate and the conductive loop surrounds the fastener holes. When the door is forced open without retraction of the bolt, a crack appears on the surface of the frame surrounding the fasteners. This crack causes a break in the conductive loop. This break is then detected by a detecting device electrically connected to a part of the loop, thereby triggering an alarm.

Intrusion sensing device

Telecommunications system console or similar article

Portable transmitter

A telephone stand is disclosed including a chassis that is enclosed within a housing comprising a cover member and a base member. The chassis is a lattice-like structure including side and end walls at the periphery thereof and at least one intermediate wall extending therebetween. The walls serve as partitions that define open-ended cubicles within which substantially all of the components contained within the housing are mounted. The height of the side, end, and intermediate walls is such that a substantial portion of each component mounted within the confines of the walls is contained within the volume defined by the upper and lower surfaces of the walls. Certain of the components and the cover member and base member are fastened to the walls.

Growing community of inventors

Indianapolis, IN, United States of America

John G Engstrom