Burglar alarm triggered by breaking of a magnetic circuit

Claim 2

A burglar alarm comprising, in combination: an alarm signal generator; a first magnetically attractable member movable between spaced positions of alarm set and alarm and continuously urged to said alarm position; a second magnetically attractable member disposed in spaced proximity to said alarm set position; at least one of said first and second members being magnetic, said first and second members cooperating to define a first magnetic circuit at said alarm set position whereby to maintain said first member at said alarm set position, said first and second members being relatively movable whereby to break said first magnetic circuit releasing said first member to move to said alarm position; and circuit means connected to said signal generator comprising electrical contacts, spaced from one another and from said first member at said alarm set position, defining said circuit as open, said first member effecting electrical contact and bridging of said spaced contacts when said first member is moved to said alarm position thereby closing said circuit.

Claim 3

The invention according to claim 1 in which said first and second members are both magnetic.

Claim 4

The invention according to claim 1 in which said spaced contacts are nonmagnetic.

Claim 5

A burglar alarm comprising, in combination; an alarm signal generator; a first magnetically attractable member movable between spaced positions of alarm set and alarm; a second magnetically attractable member disposed in spaced proximity to said alarm position; at least one of said first and second members being magnetic, said first and second members cooperating to define a first magnetic circuit at said alarm set position whereby to maintain said first member at said alarm set position; a third, magnetically attractive, member in proximity to said alarm position, at least one of said first and third members being magnetic, said first and third members cooperating to define a second magnetic circuit at said alarm position and thereby continuously urge said first member to said alarm position whereby upon breaking of said first magnetic circuit said first member is magnetically drawn to said third member; and circuit means connected to said signal generator and cooperating with said first movable member for energizing said signal generator when said first movable member is at said alarm position; said first and second members being relatively movable to break said first magnetic circuit whereby said first member is moved by said continuously urging means to said alarm position.

Claim 6

A burglar alarm comprising, in combination; an alarm signal generator; a first magnetically attractable member movable between spaced positions of alarm set and alarm; a second magnetically attractable member disposed in spaced proximity to said alarm position; at least one of said first and second members being magnetic, said first and second members cooperating to define a first magnetic circuit at said alarm set position whereby to maintain said first member at said alarm set position; a third, magnetically attractive, member in proximity to said alarm position, at least one of said first and third members being magnetic, said first and third members cooperating to define a second magnetic circuit at said alarm position and thereby continuously urge said first member to said alarm position whereby upon breaking of said first magnetic circuit said first member is magnetically drawn to said third member; and circuit means connected to said signal generator and cooperating with said first movable member for energizing said signal generator when said first movable member is at said alarm position; said first and second members being relatively movable to break said first magnetic circuit whereby said first member is moved by said continuously urging means to said alarm position.

Claim 7

A burglar alarm comprising, in combination: an alarm signal generator; a first magnetically attractAble member movable between spaced positions of alarm set and alarm, said alarm position being spaced below said alarm set position whereby said first member is continuously urged to said alarm position by the force of gravity; a second magnetically attractable member disposed in spaced proximity to said alarm set position; at least one of said first and second members being magnetic, said first and second members cooperating to define a first magnetic circuit at said alarm set position to maintain said first member at said alarm set position, said first and second members being relatively movable to break said first magnetic circuit releasing said first member to move to said alarm position; and circuit means connected to said signal generator and cooperating with said first movable member for energizing said signal generator when said first movable member is at said alarm position.

Claim 8

A burglar alarm comprising, in combination: an alarm signal generator; a first magnetically attractAble member movable between spaced positions of alarm set and alarm, said alarm position being spaced below said alarm set position whereby said first member is continuously urged to said alarm position by the force of gravity; a second magnetically attractable member disposed in spaced proximity to said alarm set position; at least one of said first and second members being magnetic, said first and second members cooperating to define a first magnetic circuit at said alarm set position to maintain said first member at said alarm set position, said first and second members being relatively movable to break said first magnetic circuit releasing said first member to move to said alarm position; and circuit means connected to said signal generator and cooperating with said first movable member for energizing said signal generator when said first movable member is at said alarm position.

Claim 9

A burglar alarm comprising, in combination: an alarm signal generator; a first magnetic member movable between spaced positions of alarm set and alarm and continuously urged to said alarm position; a second magnetic member cooperating with said first magnetic member to define a magnetic circuit at said alarm set position to maintain said first magnetic member at said alarm set position, said first and second magnetic members being relatively movable to break said first magnetic circuit releasing said first magnetic member to move to said alarm position; and circuit means connected to said signal generator comprising electrical contacts, spaced from one another and from said first magnetic member at said alarm set position, defining said circuit as open, said first magnetic member contacting and bridging said spaced contacts when moved to said alarm position to close said circuit.

Claim 10

A burglar alarm comprising, in combination: an alarm signal generator; a first magnetic member movable between spaced positions of alarm set and alarm and continuously urged to said alarm position; a second magnetic member cooperating with said first magnetic member to define a magnetic circuit at said alarm set position to maintain said first magnetic member at said alarm set position, said first and second magnetic members being relatively movable to break said first magnetic circuit releasing said first magnetic member to move to said alarm position; and circuit means connected to said signal generator comprising electrical contacts, spaced from one another and from said first magnetic member at said alarm set position, defining said circuit as open, said first magnetic member contacting and bridging said spaced contacts when moved to said alarm position to close said circuit.

Claim 11

The invention according to claim 6 including a third magnetic member spaced further than said electrical contacts from said first magnetic member and disposed to continuously urge said first magnetic member to said alarm position.

Claim 12

A burglar alarm comprising, in combination: an alarm signal generator; a first magnetic member movable between spaced positions of alarm set and alarm; a second magnetic member; said first and second magnetic members cooperating to define a magnetic circuit at said alarm set position to maintain said first member at said alarm set position; and means for cooperating with said first magnetic member to define a second magnetic circuit at said alarm position and thereby continuously urge said first magnetic member to said alarm position whereby upon breaking of said first magnetic circuit said first magnetic member is magnetically drawn to said means, said means comprising circuit means connected to said signal generator and cooperating with said first magnetic member for energizing said signal generator when said first member is at said alarm position; said first and second members being relatively movable to break said first magnetic circuit whereby said first member is moved by said continuously urging means to said alarm position.

Claim 13

A burglar alarm comprising, in combination: an alarm signal generator; a first magnetic member movable between spaced positions of alarm set and alarm; a second magnetic member; said first and second magnetic members cooperating to define a magnetic circuit at said alarm set position to maintain said first member at said alarm set position; and means for cooperating with said first magnetic member to define a second magnetic circuit at said alarm position and thereby continuously urge said first magnetic member to said alarm position whereby upon breaking of said first magnetic circuit said first magnetic member is magnetically drawn to said means, said means comprising circuit means connected to said signal generator and cooperating with said first magnetic member for energizing said signal generator when said first member is at said alarm position; said first and second members being relatively movable to break said first magnetic circuit whereby said first member is moved by said continuously urging means to said alarm position.

Claim 14

The invention according to claim 8 in which said circuit means comprises a switch having a spring which loads the switch to close said signal generator circuit, said switch being carried by said first member against the force of its spring at said alarm set position whereby to open said signal generator circuit.

Claim 15

The invention according to claim 8 in which said means additionally comprises a third magnetic member in proximity to said alarm position.

Claim 16

A burglar alarm comprising, in combination: an alarm signal generator; a first magnetic member movable between spaced positions of alarm set and alarm, said alarm position being spaced below said alarm set position whereby said first member is continuously urged to said alarm position by the force of gravity; a second magnetic member cooperating with said first magnetic member to define a first magnetic circuit At said alarm set position to maintain said first magnetic member at said alarm set position, said first and second members being relatively movable to break said first magnetic circuit and release said first member to move to said alarm position; and circuit means connected to said signal generator and cooperating with said first magnetic member for energizing said signal generator when said first magnetic member is at said alarm position.

Claim 17

A burglar alarm comprising, in combination: an alarm signal generator; a first magnetic member movable between spaced positions of alarm set and alarm, said alarm position being spaced below said alarm set position whereby said first member is continuously urged to said alarm position by the force of gravity; a second magnetic member cooperating with said first magnetic member to define a first magnetic circuit At said alarm set position to maintain said first magnetic member at said alarm set position, said first and second members being relatively movable to break said first magnetic circuit and release said first member to move to said alarm position; and circuit means connected to said signal generator and cooperating with said first magnetic member for energizing said signal generator when said first magnetic member is at said alarm position.

Claim 18

A burglar alarm, comprising: an alarm signal generator; a housing having spaced front and rear walls; a first magnetically attractable member between said front and rear housing walls, spaced from one thereof and movable between spaced positions of alarm adjacent said one wall and alarm set adjacent the wall opposite said one wall; a second magnetically attractable member disposed externally of said housing front wall, at least one of said first and second members being magnetic, said first and second members cooperating to define a first magnetic circuit at said alarm set position whereby to maintain said first member at said alarm set position; magnetically attractive means in said housing adjacent said opposite wall for cooperating with said first magnetic member to define a second magnetic circuit at said alarm position and thereby continuously urge said first magnetic member to said alarm position whereby upon breaking of said first magnetic circuit said first member is magnetically drawn to said means, said means comprising circuit means connected to said signal generator and cooperating with said first member for energizing said signal generator when said first member is at said alarm position; said second member being movable respective said housing front wall to break said first magnetic circuit whereby said first member is moved by said continuously urging means to said alarm position.

Claim 19

A burglar alarm, comprising: an alarm signal generator; a housing having spaced front and rear walls; a first magnetically attractable member between said front and rear housing walls, spaced from one thereof and movable between spaced positions of alarm adjacent said one wall and alarm set adjacent the wall opposite said one wall; a second magnetically attractable member disposed externally of said housing front wall, at least one of said first and second members being magnetic, said first and second members cooperating to define a first magnetic circuit at said alarm set position whereby to maintain said first member at said alarm set position; magnetically attractive means in said housing adjacent said opposite wall for cooperating with said first magnetic member to define a second magnetic circuit at said alarm position and thereby continuously urge said first magnetic member to said alarm position whereby upon breaking of said first magnetic circuit said first member is magnetically drawn to said means, said means comprising circuit means connected to said signal generator and cooperating with said first member for energizing said signal generator when said first member is at said alarm position; said second member being movable respective said housing front wall to break said first magnetic circuit whereby said first member is moved by said continuously urging means to said alarm position.

Claim 20

The invention according to claim 12 in which said first and second members are both magnetic.

Claim 21

The invention according to claim 12 in which said alarm position is adjacent said rear wall.

Claim 22

A burglar alarm system, comprising: a glass window; a window cover movably disposed adjacent one side of said glass window and covering substantially all of the area of said glass window on said one side; a first magnetically attractable member on a side of said glass window opposite said first side and occupying a first minor portion only of the region of said glass window on said opposite window side; a second magnetically attractable member on said window cover adjacent said first window side and occupying a second minor portion only of the region of said window cover, said first and second minor portions at least overlapping; at least one of said first and second members being magnetic, said first and second members cooperating to define a magnetic circuit; alarm means on said opposite window side responsive to a break in said magnetic circuit whereby to generate an alarm signal; and means for connecting said second member to said window cover for movement therewith whereby movement of said window cover effects a break in said magnetic circuit.

Claim 23

A burglar alarm system, comprising: a glass window; a window cover movably disposed adjacent one side of said glass window and covering substantially all of the area of said glass window on said one side; a first magnetically attractable member on a side of said glass window opposite said first side and occupying a first minor portion only of the region of said glass window on said opposite window side; a second magnetically attractable member on said window cover adjacent said first window side and occupying a second minor portion only of the region of said window cover, said first and second minor portions at least overlapping; at least one of said first and second members being magnetic, said first and second members cooperating to define a magnetic circuit; alarm means on said opposite window side responsive to a break in said magnetic circuit whereby to generate an alarm signal; and means for connecting said second member to said window cover for movement therewith whereby movement of said window cover effects a break in said magnetic circuit.

Claim 24

The invention according to claim 15 wherein said window cover comprises a window screen having screen material defining said second minor portion.

Claim 25

A burglar alarm system, comprising: a glass window; a flat transparent member movably disposed adjacent one side of said window; a first magnetically attractable member on a side of said window opposite said first side and occupying a first minor portion only of the region of said glass window on said opposite window side; a second magnetically attractable member on said first window side and occupying a second minor portion only of the region of said second window side, said first and second minor portions at least overlapping; at least one of said first and second members being magnetic, said first and second members cooperating to define a magnetic circuit; alarm means on said opposite window side responsive to a break in said magnetic circuit whereby to generate an alarm signal; and means for connecting said second member to said transparent member for movement therewith whereby movement of said transparent member effects a break in said magnetic circuit.

Claim 26

A burglar alarm system, comprising: a glass window; a flat transparent member movably disposed adjacent one side of said window; a first magnetically attractable member on a side of said window opposite said first side and occupying a first minor portion only of the region of said glass window on said opposite window side; a second magnetically attractable member on said first window side and occupying a second minor portion only of the region of said second window side, said first and second minor portions at least overlapping; at least one of said first and second members being magnetic, said first and second members cooperating to define a magnetic circuit; alarm means on said opposite window side responsive to a break in said magnetic circuit whereby to generate an alarm signal; and means for connecting said second member to said transparent member for movement therewith whereby movement of said transparent member effects a break in said magnetic circuit.