Alarm bolt

Claim 2

An alarm bolt, comprising: a bolt; mounting means for mounting said bolt on a door for normal sliding movement along a path into a strike mounted on a jamb to which the door is to be bolted, said mounting means also pivotally mounting said bolt for pivotal movement out of said path; resilient means for biasing said bolt against said pivotal movement out of said path and, after said bolt has pivoted a predetermined angular displacement against said resilient means out of said path, for releasably holding said bolt in said angularly displaced position; a normally open electrical circuit including means associated with said bolt for completing said electrical circuit upon said pivotal movement of said bolt out of said path; and alarm means connected in said electrical circuit for signaling when said circuit is complete.

Claim 3

The alarm bolt defined in claim 1, wherein said mounting means comprises: guide means for guiding said bolt in axial translation in a plane parallel to the door; and bearing means for pivotally supporting said bolt during said pivotal movement thereof, and also for providing bearing support for said bolt during axial translation thereof.

Claim 4

The alarm bolt defined in claim 1, wherein said mounting means comprises: a metal bracket having a base and connected thereto a pair of spaced upstanding legs; means defining an aperture in each leg for receiving said bolt and guiding axial translation thereof; bearing means formed on said base for providing fulcrum support for said bolt during pivotal movement thereof and also for providing bearing support for said bolt during axial translation thereof.

Claim 5

The alarm bolt defined in claim 1, wherein said resilient means comprises: resilient spring means for holding said bolt in said path and operative to release said bolt for pivoting out of said plane upon application of a predetermined force thereagainst, and also for holding said bolt in said angularly displaced position until application of a predeteRmined force sufficient to restore said bolt to said path, said resilient spring means comprising a pair of arms bracketing said bolt, each of said arms having a protrusion formed thereon extending inwardly toward and operatively engaging said bolt.

Claim 6

The alarm bolt defined in claim 1, wherein said resilient means comprises: bistable spring means having a first stable position holding said bolt in a first angular position parallel to said door, and operative to yield to a predetermined force and allow said bolt to pivot out of said first angular position into a second angular position angularly displaced from said first angular position, whereat said spring means is in a second stable position releasably holding said bolt in said second angular position until application of a predetermined force sufficient to restore said bolt to said plane.

Claim 7

The alarm bolt defined in claim 5, wherein: said bistable spring means comprises a pair of spring arms bracketing said bolt, at least one of said arms having a protrusion formed thereon and extending inwardly toward and operatively engaging said bolt; and said mounting means comprises a metal bracket having a base and connected thereto a pair of spaced upstanding legs, and means defining an aperture in each leg for receiving said bolt and guiding said axial translation thereof; one of said apertures being sufficiently enlarged to permit angular displacement of said bolt from said first angular position to said second angular position, and bearing means formed on said base for providing fulcrum support for said bolt during pivotal movement thereof and also for providing bearing for said bolt during axial translation thereof.

Claim 8

The alarm bolt defined in claim 5, further comprising intermediate means connected to said bolt, and cooperating with said mounting means and said resilient means for: bearing said resilient means in said second angular position of said bolt; limiting said axial translation of said bolt; pivoting said bolt to said normal operating plane when said bolt is axially translated away from engagement with said strike; and providing a hand grip for manual manipulation of said bolt.

Claim 9

The alarm bolt defined in claim 7, wherein said intermediate member comprises: an elongate bar; a knob connected to said bar for manual manipulation of said bolt; means formed in opposite lateral sides of said bar defining a pair of longitudinal notches for cooperating with one of said upstanding legs for guiding and limiting axial translation of said bolt; and a raised plateau extending above the top surface of said bar and having sloping sides tapering downward from the top of said plateau to the back surface of said bar, said plateau being formed immediately adjacent to the ends of said notches, whereby axial translation of said bolt when said protrusion is engaged with one of the lateral sides of said intermediate member will carry one of the sloping plateau sides into registry with said protrusion which, bearing against said sloping side, will cause said bolt to pivot inwardly.

Claim 10

The alarm bolt defined in claim 4, further comprising a monostable-bistable spring system formed by the cooperation of said resilient spring means and an intermediate member connected to said bolt and through which forces may be exerted on said bolt, said intermediate member including an elongate bar, a knob connected to a first section of said bar for manual manipulation of said bolt, a third section of said bar having perpendicular lateral sides, a second section of said bar having sloping sides tapering backward from the top of said second section to the back surface of said bar, said second section being formed immediately adjacent to the third section of said bar, said protrusions bearing against the top of said third section to bias said bolt in its normal operating path, but said spring arms will yield and spread upon application of a predetermined force to allow said bolt to pivOt upwardly out of its normal operating path into an angularly displaced position whereat the lateral sides of said third section will be engaged by said protrusions and said bolt will be held in said angularly displaced position until application of a return force of predetermined magnitude, whereby axial translation of said bolt when said protrusions are engaged with said perpendicular lateral sides of said third sections will carry said sloping sides of said second section into registry with said protrusions which, bearing against said sloping sides, will cause said bolt to pivot inwardly, wherein said resilient spring means cooperates with said second section to form a monostable system and with said third section to form a bistable system.

Claim 11

An alarm bolt, comprising: a bolt; a bracket for mounting said bolt on a door for normal sliding movement along a path into a strike mounted on a jamb to which the door is to be bolted, said bracket also pivotally mounting said bolt for pivotal movement out of said path; a spring including a spring arm having a projection thereon extending toward said bolt, said arm disposed adjacent said bolt with said projection bearing against said bolt on an edge thereof which moves in a single plane during both pivotal and sliding movement of said bolt; surface means on said bolt which, in the fully locked position of said bolt, forms with said spring a bistable system such that said bolt when in the plane of its normal sliding path will be biased by said spring to remain in the plane of said normal sliding movement path and, after said bolt has been moved against said spring to an angularly displaced position out of the plane of said normal sliding movement path, said bolt will be releasably gripped and held by said spring in said displaced position; said surface means on said bolt, in a partially unlocked position of said bolt, forming with said spring a monostable system which is stable with the bolt in its normal sliding path only, such that when said bolt is in said partially unlocked position, said bolt will be biased by said spring to the plane of said normal sliding movement path.

Claim 12

An alarm bolt, comprising: a bolt; a bracket for mounting said bolt on a door for normal sliding movement along a path into a strike mounted on a jamb to which the door is to be bolted, said bracket also pivotally mounting said bolt for pivotal movement out of said path; a spring including a spring arm having a projection thereon extending toward said bolt, said arm disposed adjacent said bolt with said projection bearing against said bolt on an edge thereof which moves in a single plane during both pivotal and sliding movement of said bolt; surface means on said bolt which, in the fully locked position of said bolt, forms with said spring a bistable system such that said bolt when in the plane of its normal sliding path will be biased by said spring to remain in the plane of said normal sliding movement path and, after said bolt has been moved against said spring to an angularly displaced position out of the plane of said normal sliding movement path, said bolt will be releasably gripped and held by said spring in said displaced position; said surface means on said bolt, in a partially unlocked position of said bolt, forming with said spring a monostable system which is stable with the bolt in its normal sliding path only, such that when said bolt is in said partially unlocked position, said bolt will be biased by said spring to the plane of said normal sliding movement path.

Claim 13

The alarm bolt defined in claim 10, wherein said surface means comprises intermediate means connected to said bolt, and cooperating with said mounting means and said resilient means for: bearing said resilient means in said angularly displaced position of said bolt; limiting said sliding movement of said bolt; pivoting said bolt to the plane of said normal sliding path when said bolt is slid to said partially unlocked position; and providing a hand grip for manual manipulation of said bolt.

Claim 14

The alarm bolt defined in claim 11, wherein said intermediate member comprises: an elongate bar; a knob connected to said bar for manual manipulation of said bolt; means formed in opposite lateral sides of said bar defining a pair of longitudinal notches for cooperating with one of said upstanding legs for guiding and limiting normal sliding movement of said bolt; and a raised plateau extending above the top surface of said bar and having sloping sides tapering downward from the top of said plateau to the back surface of said bar, said plateau being formed immediately adjacent to the ends of said notches, whereby normal sliding movement of said bolt when said protrusion is engaged with one of the lateral sides of said intermediate member will carry one of the sloping plateau sides into registry with said protrusion which, bearing against said sloping side, will cause said bolt to pivot inwardly.