Alarm device for indicating the removal of a fire extinguisher

Abstract

The weight of a fire extinguisher depresses a first plunger which in turn maintains a second plunger retracted so as to hold open or deenergize an alarm. When the fire extinguisher is removed, the first plunger moves upwardly out of its obstructive or interfering relation with the second plunger so that the second plunger advances from its retracted position to energize or activate the alarm. Once the alarm is triggered into operation, a slidable drawer must be unlocked and pulled open to reset the alarm.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to fire extinguishers, and pertains more particularly to an alarm device that is automatically sounded when the fire extinguisher is removed from the device.

2. Description of the Prior Art

Various alarm devices have been used in the past in conjunction with glass paneled doors containing the fire extinguisher. When the door is opened, the alarm is sounded. The weight of the extinguisher plays no role in this type of protective arrangement.

SUMMARY OF THE INVENTION

A primary object of the invention is to effectively thwart the unauthorized removal of fire extinguishers. In this regard, an aim of the invention is to provide an alarm that is triggered into operation when the fire extinguisher is taken but which alarm cannot be inactivated or reset by the person removing the fire extinguisher.

Another object of the invention is to provide an alarm device that can be reset only by an authorized person, the resetting operation first requiring the unlocking of a slidable drawer.

Still another object is to provide an alarm device that is completely self-contained, there being no external wiring or any parts that can be manipulated or detached by unauthorized persons.

Another object is to discourage the taking of a fire extinguisher by reason of it being apparent that an alarm is associated with the casing supporting the fire extinguisher, this being due to the visibility of the face of the lock and the keyhole therein.

Another object is to provide an alarm device that will not interfere with the removal of the fire extinguisher when actually needed to extinguish a fire.

Yet another object of the invention is to provide an alarm device that will accommodate various sizes of fire extinguishers.

Another object is to audibly signal the unauthorized taking of the fire extinguisher without having to modify in any way the fire extinguisher being protected.

Still another object of the invention is to provide an alarm device that is versatile as to its manner of mounting in that it can be mounted directly on a building wall or located within a cabinet that is mounted on the wall.

A further object of the invention is to provide an alarm device that will be relatively inexpensive to manufacture, thereby encouraging its widespread use.

Briefly, my invention comprises a casing having top, sides, rear and bottom walls but open at the front. Toward the rear of the top wall is located a vertically reciprocal plunger, the plunger being biased upwardly by a coil spring. When the fire extinguisher is placed on the casing, then the plunger is depressed. A slidable drawer is insertable through the front opening, the drawer having a front wall that then blocks the casing opening. A second plunger is mounted in the drawer for horizontal reciprocation, being spring biased toward the first plunger. When the first plunger is depressed by a fire extinguisher, then the second plunger is held in a retracted or cocked position to keep a switch open, thereby deenergizing or inactivating the alarm. When the first plunger is permitted to move upwardly, which it does when the fire extinguisher is removed, then the second plunger advances so as to close the switch and thus trigger or energize the alarm.

A cylinder lock is mounted on the front wall of the drawer. The lock has a latch member thereon which is key-rotated into a downwardly extending position, the latch member then passing through aligned holes, one being in the bottom of the drawer and the other in the bottom wall of the casing. Thus, in order to reset the alarm, it is necessary to first unlock the drawer, pull the drawer out, depress the first plunger (by placing a fire extinguisher thereon), and then sliding the drawer back into the casing to produce the retracted or cocked condition of the second plunger.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a side elevational view of my alarm device with a conventional fire extinguisher supported thereon;

FIG. 2 is a perspective view of the device itself, the fire extinguisher having been removed;

FIG. 3 is a vertical sectional view taken generally in the plane of the plunger and key of FIG. 2 but with the fire extinguisher of FIG. 1 thereon, only the lower portion thereof, however, being illustrated;

FIG. 4 is a schematic view showing the manner in which the alarm is maintained in an inactive or cocked state, and

FIG. 5 is a schematic diagram showing the alarm after it has been activated or triggered into operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT

My alarm device has been designated generally by the reference numeral 10. The exemplary device 10 includes an upstanding mounting panel 12 at the rear thereof having four holes 14 therein. As can be understood from FIG. 1, the holes 14 accommodate screws 16 which extend into the wall labeled 18. Various ways of attaching the panel 12 can be employed, the screws 16 being a simple expedient that permits a facile illustration thereof.

The mounting panel 12 has a pair of vertically spaced spring clips 20, the clips 20 being anchored to the mounting panel 12 by rivets 22. The function of the clips 20, as is believed evident, is to releasably hold in place a conventional fire extinguisher 24.

At the lower end of the mounting panel 12 is a retangular casing 26 composed of a top wall 28, spaced side walls 30 and a bottom wall 32. The rear wall 34 is merely a downward extension of the mounting panel 12. The casing 26 has an opening 36 at its front end.

A hole 38 is provided in the top wall 28 at a location near the rear of the casing 26. Having its upper end secured to the top wall 28, such as by brazing, is a downwardly depending sleeve 40 having an inturned flange 42 at its lower end. Vertically reciprocal in the sleeve 40 is a plunger 44 having an enlarged head 46 at its upper end, the plunger 44 being of sufficient length so as to project beyond the lower end of the sleeve 40 when depressed, as can be discerned from FIG. 3. Contained in the sleeve 40 is a coil spring 48, the lower end of the coil spring 48 bearing against the inturned flange 42 and the upper end of the coil spring 48 bearing against the underside of the enlarged head 46. In this way, the plunger 44 is biased upwardly, the weight of the fire extinguisher 24 overcoming the biasing action of the spring 48 to cause the plunger 44 to assume the raised position appearing in FIG. 2.

Removably received in the casing 26 is a slidable drawer denoted generally by the reference numeral 50. The drawer 50 has a front wall 52 which blocks the opening 36, spaced side walls 54, a bottom wall 56, but no top or rear wall. Secured to the bottom wall 56 of the drawer 50 is a U-shaped metal bracket 58 comprised of horizontal flanges 60 at each end, upwardly extending end walls 62, 64 and a horizontal top panel 66. The flanges 60 are welded or otherwise secured to the bottom wall 56 of the drawer 50.

A switch unit 68 is mounted to the wall 62 of the U-shaped bracket 58. To effect the mounting, the switch unit 68 has a threaded bushing 70, there being a nut 72 and a nut 74 to either side of the wall 62 which is apertured so that the bushing 70 is fastened in place. The switch unit 68 also includes a plastic housing 76, the bushing being anchored thereto by a retainer 77. Mounted for horizontal reciprocal movement through the bushing 70 is a plunger 78 having an enlarged head 80. To simplify the drafting, the plunger 78 has been shown with a metal washer 82 adjacent its head 80, the washer being movable with the plunger 78 to bridge a pair of fixed contacts 84. There is a coil spring 86 contained within the housing 76 that normally biases the plunger 78 to the left as viewed in FIG. 3, one end of the spring 86 bearing against the head 80 and the other end against the housing 76.

It should be evident from FIG. 3 that when the plunger 44 is depressed, then the plunger 78 is held in a retracted position and the switch unit 68 is open because the contacts 84 are not at this time bridged by the metallic washer 82. However, when the plunger 44 rises, then the plunger 78 is advanced under the influence of the spring 86 to bridge the contacts 84. The contacts 84 have conductors 88, extending to a pair of bayonet type terminals 90 and 92 which project from the housing 76.

The terminal 90 is mated with a slip-on terminal 94 having a conductor 96 extending to a small contact battery terminal board 98. The battery terminal board 98 has a pair of snap-on terminals 100, 102, one being a male terminal and the other a female terminal so as to accommodate the terminals on a conventional 9 volt battery 104, such as is customarily used to power transistor radios.

Whereas the conductor 96 is connected to the terminal 100 of the small board, the other terminal 102 has a conductor 106 extending to one side of a high pitched electromagnetic alarm 108, comprising a speaker, speaker supported on the top panel 66 of the bracket 58, a portion 108a of the speaker extending downwardly through a circular opening in the panel 66. The other terminal 92 on the switch unit 68 is mated with a slip-on terminal 110 having a conductor 112 extending to a screw 114 that is attached to the top panel 66 of the U-shaped bracket 58. The panel 66 itself is connected to the other side of the alarm 108. Consequently, when the contacts 84 are bridged by the washer 82, a circuit is completed from the battery 104 through the contacts 84 and the coil of the speaker 108.

In order to prevent the unauthorized removal of the drawer 50, the front wall 52 thereof has a cylinder lock 116 mounted therein. The lock 116 has an escutcheon plate or flange 118 that confronts the forward side of the front wall 52. Confronting the back side of the front wall 52 is a nut 119, the exterior of the lock's barrel 120 being threaded for the accommodation of the nut 119. The rear end of the plug 122 rotatable in the barrel 120 has mounted thereon a latch member 124 that can be rotated between a horizontal position in which it is completely within the confines of the drawer 50 to a vertical position (FIG. 3) where it extends downwardly through a transverse slot 126 in the bottom wall 56 of the drawer 50 and an aligned slot 128 in the bottom wall of the casing 26. When extending vertically down through the two slots 126, 128, the drawer 50 is locked within the casing 26 and cannot be removed until the latch member 124 is rotated upwardly into a horizontal position so as to permit the drawer 50 to be pulled outwardly. A key 129 is shown which locks and unlocks the cylindrical lock 116. When the drawer 50 is fully inserted, as indicated in FIG. 3, the speaker 108 assumes a position directly beneath a cluster of holes 130 (FIG. 2) formed in the top wall 28 of the casing 26 so that the sound from the speaker 108 can pass upwardly and outwardly into the surrounding area.

Operation

The manner in which my alarm device 10 functions is extremely simple. It will perhaps be the easiest to refer to FIGS. 4 and 5 for the operational sequence. In FIG. 4, the vertically reciprocal plunger 44 is held depressed by reason of the weight of the fire extinguisher 24. Thus, the positional relationship appearing in FIG. 4 corresponds to that of FIG. 3. The arrow 132 in FIG. 4 indicates the direction of the biasing action supplied by the coil spring 48 shown in FIG. 3. The other arrow 134 signifies the biasing action supplied by the coil spring 86 of FIG. 3. It will be obvious that the depressed plunger 44 is in an obstructive or interfering relation with the plunger 78, thereby holding the plunger 78 in a retracted or cocked position so that the plunger 78 cannot move in the direction of the arrow 134. Stated somewhat differently, the two plungers 44, 78 are mounted for axial movement along two mutually intersecting paths.

However, when the plunger 44 moves upwardly in the direction of the arrow 132 shown in FIG. 4, it reaches the upper position illustrated in FIG. 5, which position also appears pictorially in FIG. 2. This condition happens when the fire extinguisher 24 is removed from the top wall 28 which functions as a supporting platform for the extinguisher 24. As soon as the plunger 44 moves upwardly, then the plunger 78 can advance rearwardly in the direction of the arrow 134 appearing in FIG. 4. The two plungers 44, 78 thus assume the relative positions illustrated in FIG. 5. It is important to note that the contacts 84 at this time are bridged by the metal washer 82, thereby closing the circuit to the alarm 108, power flowing from the battery 104 through the alarm 108 so that a high pitch sound is produced.

The sound emitted by the alarm 108 emanates upwardly through the cluster of holes 130 in the top wall 28 of the casing 26. There is no top wall to the drawer 50 so there is a clear avenue of escape as far as the sound is concerned. The audible alarm thus serves as a warning to anyone in the vicinity that the fire extinguisher 24 has been removed.

While the proper removal of the fire extinguisher 24 also sets off the alarm, if a fire has indeed occurred, then the highly audible signal additionally performs the important function of warning people in the vicinity that a fire has occurred. If the removal is unauthorized, such as by a vandal or thief, then the sounding of the alarm calls attention to this act. Consequently, my invention will find especial utility in various public buildings, particularly schools, where passers-by are apt to be present and would automatically take note of the unauthorized removal. On the other hand, if my device is installed in an apartment house or office building, even though someone is not present at that time when the fire extinguisher 24 is being removed, nonetheless the sounding of the alarm arouses the tenants or occupants in the area, resulting in an immediate investigation.

Although it is believed evident from FIG. 3, FIG. 5 indicates that once the vertical plunger 44 has moved upwardly and the horizontal plunger 78 has advanced horizontally therebeneath, the vertical plunger 44 cannot thereafter be depressed. More specifically, the plunger 78 has moved beneath the plunger 44 so that any attempt to depress the plunger 44, such as to turn off the alarm, will not be successful because the lower end of the plunger 44 will simply strike the now released plunger 78.

Therefore, my device 10 will remain in a cocked position as shown in FIGS. 3 and 4 until the fire extinguisher 24 has been removed. This causes a triggering of the alarm by reason of the closing of the switch unit 68 in that the contacts 84 are now bridged by the washer 82. The switch unit 68 is literally latched closed by reason of the inability to redepress the vertical plunger 44 to the obstructive relation between it and the plunger 78 so that the alarm continues to sound until someone having the key 129 arrives so as to reset the alarm. In the meantime, any act of vandalism or thievery with respect to the fire extinguisher 24 is brought to the attention of others who are present in the vicinity.

It should be apparent that the unlocking of the drawer 50 through the agency of the key 129 causes the latch member 124 to be moved out of the position depicted in FIG. 3. When in the position of FIG. 3, the latch member 124 extends downwardly through the two slots 126, 128 so that the drawer 50 cannot be removed because the latch member 124 engages the bottom wall 32 of the casing 26 at the right side of the slot 128. When rotated upwardly, though, the latching member 124 no longer extends downwardly into the slot 128 and the drawer can be pulled forwardly or to the right as viewed in FIG. 3, the key 129 serving as a pulling expedient when partially turned.

When replacing the drawer 50 in the casing 26, it should be noted that with the fire extinguisher 24 depressing the plunger 44, the inward movement of the drawer 50 causes the horizontally reciprocal plunger 78 to abut against the depressed plunger 44 so as to cause the spring 86 to be progressively compressed as the drawer 50 is moved inwardly. Of course, the obstruction or interference created by the depressed plunger 44 keeps the plunger 78 from advancing with the drawer 50 once it engages the plunger 44. Such an occurrence moves the washer 82 away from the contacts 84 as clearly illustrated in FIG. 3 (and also in FIG. 4). Hence, when the drawer 50 is inserted under these conditions, the alarm is reset or cocked and is in continued readiness should the fire extinguisher 24 again be removed.

Claims

I claim:

1. An alarm device for indicating the removal of a fire extinguisher therefrom comprising a casing having an opening at the front, a drawer slidably received in said casing having a front wall for blocking said casing opening, an electric alarm in said drawer, a switch in circuit with said alarm, a horizontally reciprocal plunger for opening said switch in a first position thereof to inactivate said alarm and closing said switch in a second position thereof to activate said alarm, means biasing said plunger into said second position, a vertically reciprocal plunger extending downwardly through the top of said casing to a first position to retain said horizontal plunger in its first position, means biasing said vertical plunger upwardly to a second position to permit said horizontal plunger to assume its second position, and means for locking said drawer in said casing, whereby when a fire extinguisher is supported on said casing said vertical plunger is depressed sufficiently by said fire extinguisher to keep said horizontal plunger in its said first position and when said fire extinguisher is removed said horizontal plunger moves to its said second position.

2. An alarm device in accordance with claim 1 in which said casing includes top, side, rear and bottom walls, and said drawer includes front, side and bottom walls, said drawer being open at the top and rear.

3. An alarm device in accordance with claim 2 in which the rear wall of said casing extends upwardly to provide an upstanding mounting wall, and means on said mounting wall for releasably holding a fire extinguisher in position on said top wall so as to depress said vertical plunger.

4. An alarm device in accordance with claim 3 including a sleeve secured at its upper end to said top wall and extending downwardly into said casing for guiding said vertical plunger, the lower end of said sleeve terminating at an elevation above the reciprocal path traversed by said horizontal plunger.

5. An alarm device in accordance with claim 3 in which the bottom wall of said drawer and the bottom wall of said casing each have slots therein which are in alignment when said drawer is within said casing, and said lock means includes a latch member rotatable downwardly into said openings when aligned to effect the locking of said drawer within the casing.

6. An alarm device in accordance with claim 5 in which said alarm comprises an upwardly facing speaker, said top wall having a plurality of holes therein so that the sound from said speaker can pass through said casing when said alarm is actuated.

7. An alarm in accordance with claim 1 including means in said drawer for connecting a battery in circuit with said alarm and switch.

8. An alarm device for indicating the removal of a fire extinguisher comprising a casing including top, side, rear and bottom walls, said casing having a front opening a vertically reciprocal plunger extending downwardly through said top wall into said casing, said plunger being located near said rear wall, spring means normally biasing said plunger upwardly to raise the lower end of said plunger within said casing, a drawer slidably received in said casing having a front wall for blocking said casing opening, a horizontally reciprocal plunger carried in said drawer, spring means biasing said horizontally reciprocal plunger toward said vertically reciprocal plunger, said horizontal plunger engaging the lower end of said vertical plunger as said drawer is moved into said casing when said vertically reciprocal plunger is depressed by a fire extinguisher, a switch actuatable into closed position by said second biasing means when the lower end of said vertically reciprocal plunger rises under the influence of said first biasing means, an electric alarm means in circuit with said switch, said electric alarm means being energized when said switch is closed, and lock means for preventing removal of said drawer from said casing, whereby when the fire extinguisher is removed the vertical plunger rises sufficiently to permit said horizontal plunger to advance therebeneath and close said switch, said horizontal plunger then underlying said vertical plunger so that said vertical plunger cannot then be depressed again until said lock means is unlocked and said drawer pulled sufficiently open to permit said vertical plunger to move downwardly without interference from said horizontal plunger.

9. An alarm device in accordance with claim 8 in which said drawer has only bottom and side walls in addition to said front wall, said casing top wall having at least one hole therein, and said electric alarm means including a speaker disposed beneath said one hole when said drawer is received in said casing.

10. An alarm device in accordance with claim 9 in which said bottom walls have aligned slots when said drawer is received in said casing and said lock means includes a latch arm rotatable into said aligned slots to lock said drawer in said casing.