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Publication numberUS3695212 A
Publication typeGrant
Publication dateOct 3, 1972
Filing dateOct 22, 1970
Priority dateOct 22, 1970
Publication numberUS 3695212 A, US 3695212A, US-A-3695212, US3695212 A, US3695212A
InventorsGantt Kenneth T
Original AssigneeGantt Kenneth T
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Burglar alarm fixed to door or the like
US 3695212 A
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Description  (OCR text may contain errors)

ilnited States Patent Gantt [5 4] BURGLAR ALARM FIXEDTO DOOR OR THE LIKE 72 Inventor: Kenneth T. Gantt, 4224 E. 131st St., Cleveland, Ohio 44105 22 Filed: Oct. 22, 1970 21 Appl.No.: 83,082

[52] US. Cl. ..1l6/8,116/80, 116/112 [51] Int. Cl. ..E05b 45/00 [58] Field of Search ..116/8, 12, 65, 70, 80, 85, 116/86, 100, 106, 112; 70/92; ZOO/61.66, 61.64

[56] References Cited UNITED STATES PATENTS 986,799 3/1911 Byme et a1. ..116/12 1,112,316 9/1914 Percival ..200/6L64 2,789,527 4/1957 Davis ..116/75 X 3,185,127 5/1965 Chedister ..116/86 3,325,800 6/1967 Messick ..116/112 X 3,435,643 4/1969 Pollak et a1 ..70/92 3,451,369. 6/1969 Lieve et a]. ..116/86 3,561,395 2/1971 Piersma ..1 16/8 Primary Examiner-Louis J. Capozi Attorney-Baldwin, Egan, Walling & Fetzer [57] ABSTRACT A burglar alarm is provided for use in connection with a door or other closure member for a building opening. A casing embedded in the door intermediate its inside and outside faces opens at that edge of the door which is presented to the frame when the door is closed. A plunger is slidably mounted in the casing and provided with a lock or keeper which either holds the plunger locked in an inoperative position approximately flush with the edge of the door and which, in unlocked position, is pushed outwardly by a spring in an abutting position against the door frame. If the door is opened by an unauthorized person while the plunger is in its unlocked condition, then the plunger is pushed outwardly by the spring and is operatively connected with an actuator which sounds an alarm. The plunger lock is preferably a Yale-type lock having two identical plugs which are turnable by a bitted key to turn the keeper between locked and unlocked positions. By this arrangement, the same key maybe utilized to manipulate the keeper either from inside or outside the door.

8 Claims, 7 Drawing Figures PATENTEDnma m2 II I I III/l III FIG?) INVENTQR. KENNETH vT. GANTT FIGS BURGLAR ALARM FIXED TO DOOR OR THE LIKE An object of the present invention is to provide a burglar alarm of the type described which is easy to install, has only a few moving parts, and requires no maintenance between consecutive operations of the alarm device. A preferred form of the invention uses a gas operated horn for the alarm signal placed in communication with a small container holding gas under pressure which in one embodiment is pressurized Freon. The gas container and the horn may be mounted conveniently on a door, or other closure, with a valve controlling the pressure fluid operatively connected with a horizontally reciprocatable plunger housed in the thickness of the door between its two faces, which plunger is pushed outwardly by a compression spring if the door is opened while the plunger is unlocked so as to sound the horn and frighten away a burglar.

The advantages of this invention will be understood from the accompanying drawings and description and the essential features thereof will be set forth in the appended claims.

In the drawings,

FIG. 1 is a general view on a small scale of a portion of the inside face of a door which is slightly ajar showing how the alarm device of this invention may be attached to a door in operating position;

FIG. 2 is taken from approximately the line 2--2 of FIG. 1 and greatly enlarged shows the alarm device positioned in the door and including a top view of the gas container and attached horn;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a sectional view, to a smaller scale, taken along the line 4-4 of FIG. 2 and showing the keeper holding the plunger in its locked position;

FIG. 4A is a key for use in the lock of FIG. 4;

FIG. 5 is a sectional view, to a smaller scale, taken along the line 5-5 of FIG. 3 and showing the keeper in an unlocked position corresponding to the dot-dash position of FIG. 3 and wherein the plunger is free to reciprocate outwardly; while FIG. 6 is a view taken at the right-hand end of FIG. 3, enlarged, and partly in section to show a manually resettable detent which automatically holds the trigger in alarm-operative position after the plunger has been pushed outwardly by its compression spring.

This invention is herein described in connection with a swingable door which is hinged at one of its vertical edges but the invention may also be applied to a casement window or to a sliding door, or to a window sash which is slidable either horizontally or vertically to open it. Obviously all of these closure members are oscillatable between closed and open positions. The invention also is described with applicants plunger or trigger device housed in the door and normally abutting against the door frame when the door is closed but adapted to actuate an alarm when the door is opened while the plunger is unlocked and in position to be pushed outwardly by its operating spring. However, in its broadest aspect, the plunger device of this invention, or similar trigger, might be mounted either on the closure member, such as a door or window, or could be mounted on the frame which surrounds the door or window.

In FIG. I, there is shown a portion of a door 10 which has a hinge connection at 11 along one of its vertical edges to a door frame 12 which surrounds the door. It should be understood that the door will have its usual door knob which operates a catch, together with any of the usual locking devices found on doors.

Referring to FIGS. 1, 2 and 3, the door 10 has mounted upon its inner face 10a a container 13 filled with pressure fluid, such as Freon or other suitable gas, which has a fitting 14 at the top which includes a valve 15 movable by a valve actuator 16 from a closed position as shown in FIG. 2 to an open position when the actuator is moved in the direction of the arrow of FIG. 2. The gas when released from the container 13 through valve 15 passes through a pipe 17 to blow a horn 18. It should be understood that any suitable signal might be operated by other power, such as electricity, without changing the principles of this invention.

Within the door is mounted the trigger or plunger device of the present invention. To this end a generally cylindrical casing 19 in a preferred form is inserted in a cylindrical hole drilled into the door starting at the free edge of the door and extending the full depth of the casing 19 in a position intermediate the inside and outside faces of the door. The casing may be closed at its inner edge by a wall 19a as shown in FIG. 3, although those skilled in this art will understand that the hole drilled in the door might end at the point where the door itself would provide the wall 19a. Within the casing there is slidably mounted a trigger 20 having a portion of larger diameter which is snugly slidable in the casing 19 and having preferably a smaller diameter portion 21 which-in inoperative position of the plunger is either flush with the edge of the door at 10b or, in any case, extends outwardly toward the right as viewed in FIGS. 2 and 3 only sufficiently to abut the adjacent door frame 12. A compression spring 22 is normally compressed between the casing wall 19a and the plunger portion 20 so as to urge the plunger portion 21 outwardly when the latter is unlocked.

A key operated keeper 23 is shown in plunger locking position in full lines in FIG. 3 and also in the view of FIG. 4. By turning this keeper l from such position by means of a key about to be described, the keeper may be turned to the dot-dash position of FIG. 3 or the position clearly shown in FIG. 5.

Lock means is provided for moving the keeper 23 between its locking and unlocking positions either from the inside or the outside of the door 10. A preferred form of lock means is shown in FIG. 4 using two substantially identical Yale-type locks 23, one accessible by a key from inside the door and the other accessible to the same key on the outside of the door. Such locks usually consist as shown in FIG. 4 of a tumbler case 25 through the lower portion of which extends a rotatable plug 26. A plurality of locking pins are provided extending radially of the plug 26, each pin comprising a driver portion 27 in the tumbler case, urged inwardly by a light spring 28, and each pin having a plug portion 27a such that the driver portion 27 and the plug portion 27a of each pin is of identical diameter. When the key 29 is turned from the position shown in FIG. 4, the springs 28 push the pins inwardly so that the plug 26 cannot be turned by a screw driver, pin or other device. The key 29 is provided with the usual bits 29a so arranged that when the key is fully inserted in the lock, all

of the pins 27, 27a are moved simultaneously to the joining line 30 at the periphery of plug 26. In such position of the pins, the key 29 can rotate the plug 26. Usually also, such a key has blade corrugations 29b on longitudinal lines so that only a key of corresponding shape can be inserted.

The keeper 23 is part of a generally cylindrical member having end portions 23a, between which there is provided the arcuate recess 23b. This member 23, 23a is rotatably supported by collars 31 threaded into the tumbler casings 24. When the key 29 is fully inserted in its associated lock, the inner end of the key is provided with one or more projections 32 which enter registering openings 32a in the portions 23a whereby the key 29 may turn the associated plug 26 which in turn will turn the member 23, 230 between the locked position shown in FIG. 4 or the unlocked position shown in FIG. 5. The Yale-type lock shown at the lefthand side of FIGS. 4 and 5 is identical to that shown at the right-hand side thereof. The key in FIG. 4 is in position to turn keeper 23 toward unlocked position.

Preferably, an escutcheon plate 33 is applied to the free edge of the door 10 where the plunger portion 21 exits. The opening in this escutcheon plate guides the plunger portion as it passes out and in.

Although it forms no part of the present invention, an arrangement may be made for insuring that the plunger 20, 21 remains substantially in the position shown in FIG. 3 even though there might be considerable clearance between the free edge of the door and the adjacent frame 12. For this purpose, there is shown a cap 34 threaded on the outer end of the plunger portion 21 so that by turning the cap on the thread, the 'extra play between the door and the frame may be compensated for. i

The operative connection between the gas valve and its actuator 16 on the one hand and the plunger portion on the other should be understood from FIGS. 2 and 3. The actuator 16 passes through a slotted opening 35 in the inner face of the door and a registering opening in the casing 19 so that the free end of the actuator 16 rests in an opening 36 in the plunger portion 20. The slot 35a in the casing 19 to receive the actuator 16 is shown in dot-dash lines in FIG. 3 inasmuch as it occurs in the side of the casing toward the viewer.

A manually resettable detent 37 is provided in the plunger portion 21 so as to hold the plunger in extended position as shown in FIG. 6 after the plunger has been pushed to that position by the spring 22, while the plunger is unlocked. This detent is shown as having a head 37a and a flexible arm 37b which is attached to the plunger portion 21. A light compression spring 38 urges the detent to the dot-dash portion shown in FIG. 6. This permits the plunger portion 21 to extend outwardly freely through the associated opening in the escutcheon plate 33, but thereafter the spring 38 pushes the detent from the full line position to the dotdash position of FIG. 6 so as to bear against escutcheon plate 33 in case it is manually attempted to push the plunger 21 toward the left as viewed in FIGS. 3 and 6 so as to stop the noise from the alarm horn 18. Only a person familiar with this alarm would immediately detect he could manually hold the detent 37 in the full line position of FIG. 6 while returning the plunger portion 21 into the door.

It has been mentioned earlier that the casing 19 might be inserted in the door 10 merely by drilling a cylindrical hole extending inwardly from the free edge of the door. To install the lock structures 24, short openings may be bored inwardly from each face of the door of sufficient length and diameter to receive the tumbler cases 25. Then another hole of smaller diame ter may be drilled connecting the two lock structures to receive the keeper 23,2311. To this end, these parts are made small enough to pass through the same diameter as the plugs 26. In this manner, it is very simple to install this device on a standard wooden door.

The operation of this device should now be apparent. With the parts installed in the position of FIGS. 1, 2 and 3, the keeper 23 in the position of FIG. 4 and in the full line showing of FIG. 3 holds the plunger retracted inside of the door. In this condition of the parts, the door may be used freely in the normal manner. Upon going to bed at night, the housekeeper using the key 29 at the inner face of the door will turn the keeper from the locking position to an unlocking position as shown in FIG. 5 and in dotted lines in FIG. 3. Then, if anyone attempts to break in the door, as soon as the plunger portion 21 is free of the door frame 12, the spring 22 will move the plunger outwardly which will carry the valve actuator 16 toward the right as viewed in FIGS. 2 and 3 to a position where it opens valve 15 allowing the compressed gas to pass through pipe 17 to blow the horn 18. In a similar manner, with the parts in the locked position of FIG. 4, the householder may go out the door, close the same in the usual manner and using the key at the outer face of the door turn the keeper 23 180 from the full line position of FIG. 3 to the dot-dash position, or as shown in FIG. 5. Anyone attempting to break in while the householder is away will then set off the alarm.

What is claimed is:

l. A burglar alarm for use in association with a closure member oscillatable in a building opening which has. a frame member against which said closure member approximately abuts when in its closed position, comprising an alarm having an actuator movable between off and on positions, a trigger mounted in one of said members in position abutting said other member when said closure member is in said closed position, means urging said trigger toward said abutting position, a keeper operatively associated with said trigger in one position to restrain it against said urging means, an operative connection between said trigger and said actuator, lock means operatively associated with said keeper having a first position for holding said trigger in said one inoperative position corresponding to said actuator in off position and non-responsive to said urging means, and said lock means having a second position moving said keeper to a non-restraining position and releasing said trigger to the action of said urging means for free movement to an operative position in the direction of said abutting position responsive to said urging means upon oscillation of said closure member toward its open position, said operative position of said trigger corresponding to on position of said actuator.

2. A burglar alarm as defined in claim 1, wherein said closure member is a door having outside and inside faces, said lock means comprises two key-operated lock structures, one accessible by key from said outside face only and the other accessible by key from said inside face only and said lock structures each operable regardless of whether said lock means is in said first position or in said second position.

3. A burglar alarm as defined in claim 2, wherein said two lock structures are substantially identical, whereby the lock structures are operable by the same key.

4. A burglar alarm as defined in claim 3, wherein said two lock structures are of the Yale lock type each having a key-rotatable cylindrical plug having radially movable pins key-actuated between locked and unlocked positions, said lock means including an axially rotatable locking member in one rotated position interengaging said trigger in its said first position, said locking member having a second rotated position free of said trigger in its said second position, said lock means including a case holding said plugs and said locking member axially aligned, and said key when fully inserted in either of said plugs having a portion engaging said locking member whereby to rotate the latter upon key-rotation of the associated plug.

5. A burglar alarm as defined in claim 1, wherein said trigger comprises a cylindrical casing closed at one end and open at the other end, a plunger in said casing and slidable longitudinally thereof, said urging means comprises a compression spring between said closed end of said casing and said plunger for urging said plunger out of said open end of said casing, there being an opening crosswise through said casing at right angles to the axis of said casing, and said lock means comprises a keeper extending through said crosswise opening.

6. A burglar alarm as defined in claim 5, wherein said closure member is a door having outside and inside faces, said lock means comprises two lock structures, each having a rotatable locking plug, said plugs being cylinders of the same diameter, and said keeper is between said plugs and is of a size to pass through an opening snugly receiving a cylinder of said plug diameter, whereby a cylindrical hole may be bored in said door from one edge thereof parallel to and intermediate the faces of the door to snugly receive the full length of said cylindrical casing, and a second cylindrical hole may be bored through said door crosswise of said first hole and registering with said opening through said casing to snugly receive said plugs and said keeper.

7. A burglar alarm as defined in claim 1, wherein said alarm is a gas-operated horn, a pressure container is mounted on one of said closure members, a commutrigger in operative position, after movement thereof,

until said detent is reset.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3804053 *Jul 30, 1973Apr 16, 1974Terdina JCombination stop and alarm
US4935587 *Jul 8, 1988Jun 19, 1990Hannibal PattermannDevice for actuating a warning device in combination with a lock for a door, window or the like
US5197407 *Apr 10, 1992Mar 30, 1993Emma A. MacDowellSecurity device for attachment to the rails a movable door or window
EP0050580A1 *Oct 13, 1981Apr 28, 1982Guiard-Schmid, PaulAcoustic striker for locks
U.S. Classification116/8, 116/112, 116/80
International ClassificationE05B45/00
Cooperative ClassificationE05B45/00
European ClassificationE05B45/00