US3755802A - Alarm bolt - Google Patents

Alarm bolt Download PDF

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Publication number
US3755802A
US3755802A US00185308A US3755802DA US3755802A US 3755802 A US3755802 A US 3755802A US 00185308 A US00185308 A US 00185308A US 3755802D A US3755802D A US 3755802DA US 3755802 A US3755802 A US 3755802A
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US
United States
Prior art keywords
bolt
alarm
spring
path
bar
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00185308A
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English (en)
Inventor
L Bobrowski
C Suska
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Stanley Works
Original Assignee
Stanley Works
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Filing date
Publication date
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Publication of US3755802A publication Critical patent/US3755802A/en
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    • E—FIXED CONSTRUCTIONS
    • E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
    • E05B—LOCKS; ACCESSORIES THEREFOR; HANDCUFFS
    • E05B45/00—Alarm locks
    • E05B45/06—Electric alarm locks
    • E05B45/08—Electric alarm locks with contact making inside the lock or in the striking plate
    • E05B45/12—Electric alarm locks with contact making inside the lock or in the striking plate by movement of the bolt
    • E05B45/125—Electric alarm locks with contact making inside the lock or in the striking plate by movement of the bolt by transverse movement

Definitions

  • ABSTRACT An alarm bolt is slidably mounted in aligned apertures through upstanding legs of a U-shaped bracket.
  • a U- shaped spring having an inwardly extending protrusion on both upstanding arms is fastened to the bracket with the arms extending upwardly around opposite sides of the bolt.
  • the protrusions on the arms of the spring engage and yieldably hold the bolt in its normal operating plane parallel to the door, but when sufficient lateral force is applied to the bolt, the arms will spread and allow the bolt to pivot upwardly. Upward pivoting of the bolt out of its normal operating plane is permitted by an oversized aperture in one of the bracket legs.
  • This invention relates to alarm bolts, and more particularly to an alarm bolt which can be fastened to the inside surface of a door or the like.
  • the other major deterrent to entrance by the intruder into the protected building is an alarm system.
  • An alarm system by itself does not prevent entry but is intended to inhibit and terminate attempts thereat by announcing the fact of the intruders presence to the occupants and the police.
  • Alarm systems that are within the means of most homeowners have proven ineffective because intruders have been able either to deactivate the alarm shortly after it is activated or to complete their crime and depart before the police could arrive.
  • the ideal system would appear to be a combination of a bolt and an alarm system. Such a system would deny access to the intruder while announcing his efforts to gain access. Typically, however, the available combinedbolt-alarm systems do not work concurrently: the alarm is not activated until the bolt is broken. Thus, the intruder has been able to work in silence until he gained access; only after access was gained would the alarm sound. The speedy intruder would thus have time to complete his crime and escape before arrival of the police. Moreover, these combined bolt and alarm systems are very expensive and financially beyond the means of all but the most wealthy home owners.
  • the present'invention provides a novel alarm bolt of simple, rugged, reliable and inexpensive construction for locking a door or the like and for sounding an alarm when forced entry is attempted before entry is gained, to give the occupants time to summon help, which alarm can easily be silenced, but only from within.
  • the alarm bolt has a bolt mounted in a bracket for normal sliding movement in a path parallel to the door to engage a strike.
  • the bolt is also pivotally mounted in the same bracket for pivoting out of its normal sliding path when unauthorized entry is attempted.
  • a biasing spring normally holds the ,bolt in its nonnal operating path but, when sufficient force is applied, the biasing spring will yield and allow the bolt to pivot.
  • the spring then functions as a detent to catchthe bolt and hold it in its pivoted position thereby causing the alarm to continue to sound.
  • To silence the alarm it is merely necessary to slide the bolt to its opened position which will make the position of the spring-bolt system unstable and the spring will return the bolt back to its normal path.
  • an alarm bolt according to the present invention is shown having a bolt 10 slidably mounted in a bracket 12 in position to engage a strike 14 mounted on a jam 16 which cooperates with a door 18 on which the bolt is to be mounted.
  • a bolt 10 slidably mounted in a bracket 12 in position to engage a strike 14 mounted on a jam 16 which cooperates with a door 18 on which the bolt is to be mounted.
  • the bracket 12 in which the bolt 10 slides in axial translation to engage the strike 14 is a shallow U- shaped member having a pair of upstanding legs 22 and 24 joined by a flat base 23 on which is formed a laterally extending bearing ridge 25 which provides bearing support for axial translation of the bolt and also acts as a fulcrum during pivotal movement of the bolt 10 as will be explained later.
  • the legs 22 and 24 have apertures 26 and 28 respectively formed therein which are for the purpose of guiding the axial translation of the bolt 10.
  • the size of the aperture 26 in its vertical dimension, that is, normal to the plane of the door, is just sufficient to permit the bolt to slide without interference; the vertical dimension of the aperture 28 is enlarged to permit a certain degree of vertical movement of the rear end of the bolt for a purpose which will appear presently.
  • the dimension of the apertures 26 and 28 in the lateral direction, that is, parallel to the plane of the door and perpendicular to the axis of the bolt, is just sufficient to permit passage of bolt 10 without interference with the sides of the apertures.
  • the top of the aperture 28 is laterally enlarged as best seen in FIG. 3 and forms a pair of shoulders 29 at the junction of the narrow and the enlarged portion of the aperture 28.
  • the intermediate member 30 has a first section 31 at the forward end thereof, that is, the end closest to the leg 22, on which a knob 34 (see only in Fig. 1) is formed, by means of which the bolt 10 may be axially slid in bracket 12 for locking and unlocking the door. Immediately rearward, or to the right as viewed in FIG.
  • the bar is thickened and widened at 36 to form a raised plateau having lateral sloping sides which diverge vertically downward or toward the door so that the lateral width of this second or plateau section 36 of the intermediate member 30 is wider at the inside or bottom face than at the outside or top face.
  • the rear, or third section 38, of the intermediate member 30 constitutes approximately one half the length of the bar and is of the same height as the first section 31 and as wide as the widest part of the plateau section 36.
  • a pair of notches 40 are formed in the bottom lateral edges of the third section 38 and extend axially therealong rearwardly from the plateau section 36, ending slightly forward of the end of the intermediate member 30.
  • the notches 40 extend vertically approximately one half the thickness of the bar, and are approximately equal in lateral and vertical dimension.
  • the axial ends 41 of the notches 40 engage the shoulders 29 of the aperture 28 to limit the axial travel of the bolt 10.
  • the sloping plateau sides and the sides of the third section 38 cooperate with a spring 42 to function as a biasing, holding and automatic restoring arrangement for the bolt 10 as will appear presently.
  • the U-shaped spring 42 is fastened to the bracket 12 adjacent the rear leg 24 by conventional means such as a rivet 44.
  • the upstanding arms 46 of spring 42 extend upwardly around both lateral sides of the bolt 10.
  • a longitudinal protrusion 48 is formed horizontally on each of the legs 46 and extends inwardly toward the bolt 10.
  • Protrusion 48 may consist of a V-shaped bend in the leg 46 as best illustrated in FIG. 3, or they may be a welding bead or other thickening of legs 46 at that point.
  • the height at which protrusions 48 are formed on legs 46 corresponds to the height of third section 38 above the base 23 of the bracket 12 so that protrusions 48 project inwardly over the top of the intermediate member 30 and bear thereagainst.
  • Legs 46 of spring 42 thus exert a downward biasing force on the intermediate member 30 and, therethrough, on bolt 10 to prevent vertical movement thereof out of its normal operating path parallel to the door.
  • the legs 46 will momentarily spread and the bolt 10 will pivot up and abut the inside top edge of aperture 28.
  • the protrusions 48 of the legs 46 will bear against the lateral sides of the third section 38 above the notches 40, or just barely engage the top outside comers of notches 40.
  • Spring 42 thus acts as a resilient biasing means yieldably holding bolt 10 in the plane of its normal operating path, and also as a resilient grasping and holding means, operative to yieldably hold bolt 10 in its angularly displaced position after bolt 10 has been so displaced.
  • a third function of the spring 42 in combination with the intermediate member 30, that of automatic restoration of the bolt 10 to the plane of its normal operating path, will be explained in the description of operation of this preferred embodiment.
  • a suitable case may be fastened to the alarm bolt by screws extending into upstanding receptacles 50.
  • a snap-in removable grille may be received by the case to facilitate access to the arm bolt and enable transmission sound waves from the alarm.
  • the case and grille may be of the design shown in copending US. design application Ser. No. 178,852, filed Sept. 8, 1971, for Alarm Unit, assigned to the assignee of this invention.
  • the operation of the alarm bolt is as follows.
  • the vertical risepermitted the bolt 10 is limited by engagement of the top of the third section of the intermediate member 30 against the top of the aperture 28, therefore the protrusions 48 do not fully enter the notches 40 but merely bear against the lateral sides of the third section 38, or engage the top outside comers of notches 40.
  • the door 18 on which the alarm bolt is mounted is closed against the jam 16 so that the bolt 10 is axially aligned with the aperture 20 through the strike 14.
  • the knob 34 is grasped by the hand and moved to the left to cause the bolt 10 to slide axially through the apertures 26 and 28, over the bearing ridge 25, and into the aperture 20 in the strike 14 to lock the door in closed position.
  • the third section 38 of the intennediate member 30 passes upward into registry with the longitudinal protrusions 48 which then bear against the lateral sides of the third section 38 and thereby prevent bolt from swinging freely back into its plane parallel to the door.
  • the sytem formed by the cooperating spring 42 and intermediate member 30 is thus a complex bistable-monostable system which gives the bolt 10 two stable angular positions in its locked configuration: a first position for normal operation in which the bolt 10 may be shifted axially between locked and unlocked configuration, and a second position, angularly displaced from the first position in which the alarm circuit is closed by a forced entry.
  • the bolt In the unlocked configuration, the bolt has only one stable angular position namely the first or normal operating position, which explains the automatic restoring feature of the bolt.
  • a stable" position is defined for use herein as one in which the bolt 10 will remain until application of a significant force, i.e., a pound.
  • the assembly illustrated in FIGS. 2 and 3 is contained in a housing 54 which holds an alarm device such as a siren or buzzer 56, a battery 58 for energizing the buzzer 56, and a pair of normally open, closely spaced electrical contacts 60.
  • Contacts 60 are in series in the battery-buzzer circuit and when closed they complete the circuit.
  • Contacts 60 are disposed immediately above intermediate member 30 so that when bolt 10 is pivoted as described above, intermediate member 30 will engage the nearer of contacts 60 and push it into contact with the other of contacts 60 thereby completing the electric circuit and energizing the buzzer which emits an ear-splitting alarm calculated to alert the occupants of the building and frighten the discovered burglar into hasty flight.
  • the present invention may be practiced by numerous modifications and variations of the above-described preferred embodiment or best mode.
  • the spring system formed of the spring 42 and the intermediate member 30 may be replaced with a bistable spring system such as a compression or toggle spring whose line of force is shortest at the midposition between the two angular positions of the bolt 10, and which operates through a cam to return the bolt 10 to its first angular position when shifted to unlocked configuration.
  • 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.
  • a metal bracket having a base and connected thereto a pair of spaced upstanding legs;
  • 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.
  • 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.
  • 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.
  • 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.
  • said interrnediate member comprises:
  • An alarm bolt comprising:
  • 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 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.

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  • Burglar Alarm Systems (AREA)
US00185308A 1971-09-30 1971-09-30 Alarm bolt Expired - Lifetime US3755802A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US18530871A 1971-09-30 1971-09-30

Publications (1)

Publication Number Publication Date
US3755802A true US3755802A (en) 1973-08-28

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ID=22680446

Family Applications (1)

Application Number Title Priority Date Filing Date
US00185308A Expired - Lifetime US3755802A (en) 1971-09-30 1971-09-30 Alarm bolt

Country Status (5)

Country Link
US (1) US3755802A (OSRAM)
JP (1) JPS4842896A (OSRAM)
DE (1) DE2247624A1 (OSRAM)
FR (1) FR2155477A5 (OSRAM)
ZA (1) ZA726515B (OSRAM)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3938120A (en) * 1974-05-06 1976-02-10 Baltimore Brushes, Inc. Talking door sentinel
US4283718A (en) * 1979-07-02 1981-08-11 Synco National Ltd. Door alarm device
US5754107A (en) * 1997-02-18 1998-05-19 Ferrantelli; Salvatore Pressure actuated dead bolt premises intrusion alarm and intruder
RU2133983C1 (ru) * 1997-07-01 1999-07-27 Квангджу Электроникс Ко., Лтд. Устройство защиты от воровства для торгового автомата
US6020816A (en) * 1998-03-02 2000-02-01 Agozzino; Andrew Door and window lock with burglar alarm
CN105421894A (zh) * 2015-11-20 2016-03-23 成都迅德科技有限公司 新型安全锁具

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55143374U (OSRAM) * 1979-04-02 1980-10-14
FR2454501A1 (fr) * 1979-04-19 1980-11-14 Pierre Ind Serrure pour porte associee a un circuit d'alarme
DE4343242C2 (de) * 1993-12-17 1997-05-15 Bayerische Motoren Werke Ag Verstaubare Tischeinrichtung an einem Sitz
CH706137B1 (de) * 2012-02-27 2016-03-31 Introgarde Ag Schliessvorrichtung mit Drucksensor.

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1607297A (en) * 1925-11-24 1926-11-16 Charles P Northington Signal system
US1892336A (en) * 1930-05-17 1932-12-27 Welborn D England Combination window sash lock and burglar alarm
US3525830A (en) * 1967-03-14 1970-08-25 Gen Alarm Corp Lock switch devices
US3530262A (en) * 1968-01-25 1970-09-22 Gen Alarm Corp Lock switch devices
US3587080A (en) * 1969-06-16 1971-06-22 Minnesota Mining & Mfg Cylinder mounting plate and alarm actuator
US3623062A (en) * 1970-06-25 1971-11-23 Minnesota Mining & Mfg Lock alarm structure

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1607297A (en) * 1925-11-24 1926-11-16 Charles P Northington Signal system
US1892336A (en) * 1930-05-17 1932-12-27 Welborn D England Combination window sash lock and burglar alarm
US3525830A (en) * 1967-03-14 1970-08-25 Gen Alarm Corp Lock switch devices
US3530262A (en) * 1968-01-25 1970-09-22 Gen Alarm Corp Lock switch devices
US3587080A (en) * 1969-06-16 1971-06-22 Minnesota Mining & Mfg Cylinder mounting plate and alarm actuator
US3623062A (en) * 1970-06-25 1971-11-23 Minnesota Mining & Mfg Lock alarm structure

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3938120A (en) * 1974-05-06 1976-02-10 Baltimore Brushes, Inc. Talking door sentinel
US4283718A (en) * 1979-07-02 1981-08-11 Synco National Ltd. Door alarm device
US5754107A (en) * 1997-02-18 1998-05-19 Ferrantelli; Salvatore Pressure actuated dead bolt premises intrusion alarm and intruder
RU2133983C1 (ru) * 1997-07-01 1999-07-27 Квангджу Электроникс Ко., Лтд. Устройство защиты от воровства для торгового автомата
US6020816A (en) * 1998-03-02 2000-02-01 Agozzino; Andrew Door and window lock with burglar alarm
CN105421894A (zh) * 2015-11-20 2016-03-23 成都迅德科技有限公司 新型安全锁具

Also Published As

Publication number Publication date
JPS4842896A (OSRAM) 1973-06-21
ZA726515B (en) 1973-06-27
FR2155477A5 (OSRAM) 1973-05-18
DE2247624A1 (de) 1973-04-05

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