US 3,943,485 AGranted

Alarm system for three-element windows

AssigneeMarjo Systems, Inc.

InventorMartin Waldman

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Abstract

An alarm system is constructed to energize when the bottom window or the top window of a three-element window assembly is opened, so long as the third element (usually a screen) is not in its closed position in front of the window being opened or if the third element is removed from its mounting slides. The switching functions are performed by magnetic reed switches imbedded in the window frame and responsive to permanent magnets in the peripheral frame of the respective elements.

Claims9

Dependent claims

An alarm system comprising:

first, second and third elements slidably positioned within an opening having upper and lower ends;
said first element being movable between a closed position in which a lower end of said first element is adjacent said lower end of said opening and an open position in which said lower end of said first element is away from said lower end of said opening;
said second element being movable between a closed position in which an upper end of said second element is adjacent said upper end of said opening and an open position in which said upper end of said second element is away from said upper end of said opening;
said third element being movable between a down-closed position in which a lower end of said third element is adjacent said lower end of said opening and an up-closed position in which an upper end of said third element is adjacent said upper end of said opening;
first switching means switchable between first and second conditions in response to said first element being moved between its closed and open position when said third element is away from its said down-closed position or in response to said first element being moved between its closed and open position and said third element being moved from its down-closed position towards its up-closed position;
second switching means switchable between first and second conditions in response to said second element being moved between its closed and open position when said third element is away from its said up-closed position or in response to said second element being moved between its closed and open position and said third element being moved from its up-closed position towards its down-closed position;
alarm means;
and
circuit means connecting said first and second switching means to said alarm means for energization of same in response to said first or second switching means switching between its first and second conditions.

6 more elements

Dependencies are inferred from the claim text.

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Abstract

An alarm system comprising:

first, second and third elements slidably positioned within an opening having upper and lower ends;
said first element being movable between a closed position in which a lower end of said first element is adjacent said lower end of said opening and an open position in which said lower end of said first element is away from said lower end of said opening;
said second element being movable between a closed position in which an upper end of said second element is adjacent said upper end of said opening and an open position in which said upper end of said second element is away from said upper end of said opening;
said third element being movable between a down-closed position in which a lower end of said third element is adjacent said lower end of said opening and an up-closed position in which an upper end of said third element is adjacent said upper end of said opening;
first switching means switchable between first and second conditions in response to said first element being moved between its closed and open position when said third element is away from its said down-closed position or in response to said first element being moved between its closed and open position and said third element being moved from its down-closed position towards its up-closed position;
second switching means switchable between first and second conditions in response to said second element being moved between its closed and open position when said third element is away from its said up-closed position or in response to said second element being moved between its closed and open position and said third element being moved from its up-closed position towards its down-closed position;
alarm means;
and
circuit means connecting said first and second switching means to said alarm means for energization of same in response to said first or second switching means switching between its first and second conditions.

6 more elements