Abstract An alarm circuit is actuated in response to relative motion in one direction to arm the apparatus, and is actuated in response to motion in the opposite direction to initiate an alarm. The apparatus includes an actuating magnet mounted on one of two relatively movable objects, a pair of reed switches mounted on the other of the two relatively movable objects, one of which is magnetically biased towards a closed position and the other which is unbiased, whereby, relative motion in one direction between objects the actuating magnet causes the sequential operation of the reed switches, the unbiased reed switch to a momentary closure and the biased reed switch to a latched closure, and whereby relative motion of the objects in the opposite direction relative to the actuating magnet causes the unbiased reed switch to be momentarily closed while the biased reed switch is latched. The apparatus further includes an electronically operated switching means which is energized after a predetermined lapse of time after the simultaneous closure of both reed switches to cause an alarm to be sounded. For silencing the alarm a key magnet is positioned adjacent to the biasing magnet to nullify the same, permitting the reeds of the biased reed switch to open. The apparatus further includes a third reed switch which when subjected to the magnetic flux of the key magnet, will convert the apparatus into an annunciator, whereby the alarm will be sounded for a short duration each time there is a relative motion between the objects in either direction.
Inventors
👤 James P Campman
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-09 14:21
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/02; G08B13/08
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
260 words
An alarm apparatus responsive to the relative motion between two objects in one of two substantially parallel directions comprising: an actuating magnet mounted on one of said objects; a pair of magnetically actuated reed switches mounted on the other of said objects, arranged in parallel to each other and spaced from each other in the direction of motion whereby said reed switches sequentially move into juxtaposition with said actuating magnet and are actuated thereby to their closed positions; a biasing magnet associated with the reed switch which secondly arrives in juxtaposition to said actuating magnet when the said objects are moved in the other of two substantially parallel directions and arranged to produce a magnetic flux across the reeds thereof insufficient to close said reeds but strong enough when said reeds are closed to hold said reeds closed; electrically operable switching means actuated into its ''''on'''' state when both said reed switches are simultaneously in their closed positions and actuated into its ''''off'''' state when said biased reed switch is opened; means energized by said electrically operable switching means to continually sound the alarm while said electrically operable switching means is in its on state; and a key magnet, similar to the biasing magnet in polarity which, when placed in juxtaposition with said biasing magnet with its magnetic flux in opposition to the flux of said biasing magnet, for opening said biased reed switch to silence said alarm and to condition said apparatus to again be armed when the objects are moved in the opposite direction relative to each other.
Claim 2
Dependent Claim
260 words
An alarm apparatus responsive to the relative motion between two objects in one of two substantially parallel directions comprising: an actuating magnet mounted on one of said objects; a pair of magnetically actuated reed switches mounted on the other of said objects, arranged in parallel to each other and spaced from each other in the direction of motion whereby said reed switches sequentially move into juxtaposition with said actuating magnet and are actuated thereby to their closed positions; a biasing magnet associated with the reed switch which secondly arrives in juxtaposition to said actuating magnet when the said objects are moved in the other of two substantially parallel directions and arranged to produce a magnetic flux across the reeds thereof insufficient to close said reeds but strong enough when said reeds are closed to hold said reeds closed; electrically operable switching means actuated into its ''''on'''' state when both said reed switches are simultaneously in their closed positions and actuated into its ''''off'''' state when said biased reed switch is opened; means energized by said electrically operable switching means to continually sound the alarm while said electrically operable switching means is in its on state; and a key magnet, similar to the biasing magnet in polarity which, when placed in juxtaposition with said biasing magnet with its magnetic flux in opposition to the flux of said biasing magnet, for opening said biased reed switch to silence said alarm and to condition said apparatus to again be armed when the objects are moved in the opposite direction relative to each other.
Claim 3
Dependent Claim
78 words
Apparatus as set forth in claim 1 further including: a third magnetically operable reed switch spaced away from said pair of reed switches and away from said actuating magnet for shunting said electrically operable means when said key magnet is placed in juxtaposition thereto, whereby said alarm will be sounded for a short duration when said parallel reed switches are moved in either direction relative to said actuating magnet, for indicating the actuations of said relatively movable objects.