US 5,450,888 AGranted

Security screen

AssigneeRoot, Inc.

InventorsBenjamin Schwartzman, Todd Root

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Abstract

A security screen includes a rectangular frame including a top member containing a screen reel comprising a rotatable core with a length of electrically non-conductive screen material affixed thereto. The screen contains parallel electrical conductors therein running lengthwise, and transverse conductors interconnect selected pairs of the lengthwise conductors to form therewith a single continuous electrical path which is interrupted if the screen is cut. A latchable drawbar is affixed along the lower edge of the screen, so that the screen can be drawn closed, against the bias provided by two torsion springs. One end of each spring is connected to the reel's core; its other end is attached to a stationary stub shaft, which serves as a terminal for connection to an alarm. The springs are electrically joined to opposite ends of the screen's conductor path, thus serving as non-sliding rotary electrical joints.

Claims18

Dependent claims

A security screen comprising

a frame including a hollow top member and a pair of side members connected thereto,
a screen reel rotatably supported within the top member by brackets at either end of the top member,
a length of window screen material having an upper edge affixed to said reel,
said screen being woven primarily from non-conductive threads, but also comprising a plurality of longitudinal electrical conductors running in a first direction,
transverse conductor means interconnecting selected pairs of said parallel conductors to form therewith a single continuous electrical circuit which is interrupted if the screen is cut,
a drawbar affixed along a lower edge of said screen, whereby the screen may be drawn down from the reel by lowering the drawbar,
a torsion spring disposed between the reel and the bracket to bias the reel in a rotary direction tending to wind the screen onto the reel when the drawbar is allowed to move upward, said spring having a movable end connected to said reel and a stationary second end,
means for mechanically connecting said stationary second spring end to said bracket,
and a stationary electrical terminal connected to the second spring end,
wherein the movable end of the torsion spring is electrically connected to the continuous electrical path of the screen, and the stationary end of said spring may be electrically connected to an alarm system, whereby the spring serves as a non-sliding rotary electrical joint.

7 more elements

A security screen comprising

a frame including a hollow top member and a pair of side members connected thereto,
a screen reel comprising a rotatable core disposed within said top member, and a length of window screen material having an upper edge affixed to said core,
said screen being woven primarily of non-conducting threads, but having a plurality of longitudinal electrical conductors therein running in a first direction,
transverse conductors interconnecting selected pairs of said longitudinal conductors to form therewith a single continuous electrical circuit which is interrupted if the screen is cut,
a drawbar affixed along a lower edge of said screen, whereby the screen may be drawn from the reel by lowering the drawbar,
a pair of torsion springs for biasing the core in a rotary direction tending to wind the screen onto the core when the drawbar is allowed to move upward, each of said springs having a movable end connected to said reel and a stationary second end, and
means for mechanically connecting said stationary second ends to said frame, without electrically interconnecting them,
the movable ends of the torsion springs being electrically connected to opposite ends of said continuous electrical screen circuit, whereby said stationary ends of said springs may be electrically joined to an alarm system, and the springs serve as non-sliding rotary electrical joints.

5 more elements

Dependencies are inferred from the claim text.