US3715743A

US3715743A - Fire alarm signalling apparatus

Info

Publication number: US3715743A
Application number: US00083929A
Authority: US
Inventors: H Denton
Original assignee: Simplex Time Recorder Co
Current assignee: Simplex Time Recorder Co
Priority date: 1970-10-26
Filing date: 1970-10-26
Publication date: 1973-02-06
Anticipated expiration: 1990-02-06

Abstract

This invention relates to a fire alarm system and, more particularly, to an apparatus for fire alarm signaling, having an alarm actuator enclosed within a glass window and operated upon actuation to break a replaceable glass rod, including means to prevent the actuating lever from being re-set by other than authorized persons.

Description

United States Patent 1 91 Benton [111 3,715,743 1 Feb. 6, 1973 [54] FIRE ALARM SIGNALLING APPARATUS [75] inventor: Howard P. Denton, Gardner, Mass.

[73] Assignee: Simplex Time Recorder Company,

Gardner, Mass.

[22] Filed: Oct. 26, 1970 [21] App1.No.: 83,929

[52] U.S. Cl. ..340/303, 200/6108, ZOO/61.7 [51] Int. Cl. ..G08b 25/00 [58] Field of Search ..340/303, 296, 287, 304;

ZOO/61.08, 61.7

[56] References Cited UNITED STATES PATENTS 2,083,324 6/1937 Edwards ..340/303 2,726,381 12/1955 Verkuil ..200/61.08UX

OTHER PUBLlCATlONS Remote Control Station 9-23-33 303) Primary Examiner-John W. Caldwell Assistant Examiner-William M. Wannisky Attorney-Norman S. Blodgett [57] ABSTRACT This invention relates to a fire alarm system and, more particularly, to an apparatus for fire alarm signaling,

having an alarm actuator enclosed within a glass window and operated upon actuation to break a replaceable glass rod, including means to prevent the actuating lever from being re-set by other than authorized per- 7 Claims, 4 Drawing Figures 'PAIENTEDFEB ems WWW!" E .mmulliml\Uiinu. mam

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FIRE ALARM SIGNALLING APPARATUS BACKGROUND OF THE INVENTION It is common practice in municipalities to provide fire alarm boxes in various localities, which boxes are connected to the main fire station by electrical wiring. Persons observing a fire can signal the fire station of that fact. One of the difficulties experienced with many of the fire boxes is that, after a person has legitimately turned in a tire alarm, he is able to return the equipment to its former condition. This means that, if the location of the signal has not been noted in the fire station, it is difficult to determine where the alarm came from. In the case where false alarms are set, various deterrents have been set up such as glass windows which must be broken. Various other deterrents of like nature are used which are intended to indicate to the prospective user that the operation he is performing is more than a casual one. That is to say, there are certain psychological impediments to breaking glass and the like, partly, of course, thenoise that accompanies the breaking of glass. In many cases, the fire box looks exactly the same from a distance after the alarm as it did before, so it is difficult for repairmen to determine quickly in a given municipality which of the boxes need replacement of the glass plate, etc. Furthermore, because of the nature of the old type fire boxes it is difficult for a manufacturer easily to provide a particular customer with exactly the features that he wishes.

.These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.

It is, therefore, an outstanding object of the invention to provide a fire alarm system of considerable versatility, allowing a customer to select any feature or combination of features which he desires.

Another object of this invention is the provision of a fire alarm system in which the actuating lever cannot be reset for use except by authorized persons.

A further object of the present invention is the provision of a fire alarm system which has means to indicate that an alarm has been placed, which means it is readily observable from a considerable distance.

It is another object of the instant invention to provide a fire alarm system containing impediments to actuation of the alarm, wherein a signal is generated to indicate that the impedimentshave been removed.

A still further object of the invention is the provision of a fire alarm system which is simple and rugged in construction and which is capable of a long life of useful service with a minimum of maintainance.

It is a further object of the invention to provide a fire alarm system using the unit assembly principal, wherein a basic housing may be provided during manufacture with a selective number of standard parts to determine various phases of operation.

It is a still further object of the present invention to provide a fire alarm box with a frame containing a glass window for access to a main alarm actuator, wherein means are provided, when the glass window is broken, to cause the frame to extend away from the box and be clearly visible.

SUMMARY OF THE INVENTION In general, the present invention consists of a fire alarm system having a housing containing an alarm switch, and a frame overlying the housing and containing a frangible glass window. Means is provided between the glass window and the housing for operating the alarm switch, the said means being operable when the glass window is broken but only by a deliberate operation by the person breaking the window.

BRIEF DESCRIPTION OF THE DRAWINGS The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated by the accompanying drawings, in which:

FIG. 1 is a front elevational view of a fire alarm system embodying the principals of the present invention,

FIG. 2 is a vertical sectional view of the system taken on the line IIII of FIG. 1,

FIG. 3 is a view of the invention taken on the line Ill-III of FIG. 2, and

FIG. 4 is a back elevational view of the apparatus with a rear plate removed.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1, wherein is best shown the general features of the invention, the fire alarm system, indicated generally by the reference numeral 10, is provided with a base 12 (see FIG. 2) which is adapted to be fastened to a telephone pole or a like mounting and a box-like enclosure 13. The enclosure is hingedly attached to the base in a manner which will be described more fully hereinafter. Mounted on the front surface of the enclosure is an actuating lever 14.

Hingedly mounted on the front surface of the enclo sure is a frame 15 having an opening containing a frangible glass window 16. Hanging from the upper portion of the frame is the hammer 17 having a lower weighted end which lies in front to the center of the window 16. Mounted on the enclosure above the frame is a key-operated lock 18 which serves to hold the two parts of the housing together.

FIG. 2 shows quite well the general inter-relationship of the parts of the invention. For instance, it can be seen that the primary alarm switch 19 is mounted in the housing (more specifically, on the base 12) and is provided with a forwardly-directed plunger 21. The switch is of the type that is in open condition when the plunger is pressed rearwardly and in closed condition when it is allowed to extend forwardly. The actuating lever 14 is swingably mounted on the enclosure 13 by means of a hinge shaft 22. The enclosure 13 is provided with an opening 23 and the lower part of the actuating lever 14 extends into this opening and isformed with a cam 24. This cam has a curved surface which is generally concentric with the hinge shaft 22. When the actuating lever is in the normal upright position shown in FIG. 2, the cam maintains the plunger 21 in its inwardly-pressed position, so that .the switch 19 is open. The cam, however, is provided with a notch 25 defining a shoulder 26. When the lever has been rotated approximately degrees, the plunger 21 falls into the notch and it is impossible to swing the lever in the reverse direction because the shoulder 26 strikes the side of the plunger and prevents it. Extending from the front face of the enclosure 13 and slidedly mounted therein is a 1 pin 28. The back end of the pin lies in the enclosure 13 gages a notch 32 on a finger 33. This finger is integrally formed with and extends rearwardly from the upper part of the frame 15. It is received in a small aperture in the enclosure 13, so that it extends into the interior of the housing for engagement by the hook. The rocker arm 29 is spring-biased in such a direction that the hook 31 'would remain clear of the notch 32 if it were not for the fact that the rearward pressure of the pin 28 keeps the hook in the notch. The pin 28 is pressed rearwardly by the pressure of the glass window 16 but only so long as the glass is present.

FIG. 2 shows that the lock 18 is provided with a laterally-extending swingable lug 34 which engages an which is preferably of the key-operated type. An aper-.

'ture 37 is formed in the enclosure 13 to give an authorized person access to the switch, but this aperture is norm ally covered by the actuating lever 14 when I it is in its normal, upright position and is also covered by the glass window 16.

' FIG. 3, taken in conjunction with FIG. 2, shows the manner in which the enclosure 13 is hinged to the base 12. A heavy-gage wire element 38 is fastened to the inner surface of the base 12. This element is generally a straight length of wire with the exception of two spaced loops by which the wire is bolted to the base. The ends of the wire extend laterally sideways from the base and enclosure 13. A shoulder 27 provided on the cam 24 .for engagement with a glass rod 39 which lies in notches in the enclosure 13 and which is exposed to view through the opening 23. It can be seen in FIG. 2 that the rod is held in place in the groove in the enclosure 13 by lugs 41 which extend forwardly from the base 12.

Referring now to FIG. 4, which shows the back view of the enclosure 13 with the base 12 removed. The manner in which the rocker arm 29 is mounted can be seen particularly well. Hinge pins 42 extend from the ends of a cross-piece 43. Extending downwardly from the cross-piece are springs 44 which engage the surface of the base 12 and tend to keep the hooks out of the notches 32. This view also shows the manner in which the shaft 22 is provided with a torsion spring 45 which biases the shaft 22 in rotation to keep the actuating lever 14 pressed toward an upward position. Mounted in the enclosure 13 is a pin 46 (see also FIG. 1) which engages the actuating member of switch 47. This actuating member is spring-like and tends to keep the pin 46 pushed forwardly into engagement. It is in engagement'with the surface of the frame 15, so that the switch gives an indication of whether or not the frame 15 is in its upper locked position or not.

The operation of the fire alarm system will now be readily understood in view of the above description.

Normally, the apparatus is in the condition shown in the drawings, that is to say, with the frame 15 against the front face of the enclosure 13 and with the hammer l7 hanging down in front of the window 16. The pin 46 is pushed rearwardly, allowing the switch 47 to indicate at a remote station the fact that the frame is in its normal condition. The frame is, of course, maintained in the upright position by the hooks 31 and the notches 32 of the fingers 33. These hooks are maintained in that locking position by the pressure of the glass window 16 against the pin 28. The housing is kept in a locked condition by the lug 34 engaging the aperture 35. It is kept in that condition by the lock 18. The cam 24 engaging the plunger 21 maintains the switch 19 in non-alarm condition. The access to the general alarm switch 36 is prevented not only by the presence of the window 16 but also by the fact that the actuating lever 14 is in an upright position that covers the aperture 37.

If one wishes to turn in a fire alarm, it is first of all necessary to break the glass 16. This is done by grasping the hammer l7 and striking the glass to break it. The moment the glass is broken, the pin 28 is allowed to extend-forwardly and release the hook 31 from the notch 32. This is because the springs 44 bias the rocker arm 43 in the counter-clock-wise direction (as observed in FIG. 2). The moment the hooks are removed from the notches in the fingers 33, the frame 15 swings downwardly because of the rotational couple provided by the hammer 17. It falls down into the outwardlydirected position at the bottom of the box where it can -be readily seen from a considerable distance. In this lower condition the hammer 17 also extends retro-reflective paint so that it can be seen at night for some considerable distance. It is obvious when this condition exists that the alarm box is in used condition."

Now, once the frame and the glass window have been removed, it is possible to grasp the upper part of the actuating lever 14 and pull it downwardly. During rotation, the shoulder 27 strikes the glass rod 39, and it is necessary that this rod be broken before it can be swung any further. After the glass rod has been broken, it is then possible to continue the rotation of the actuating lever until the plunger 21 of the switch 19 falls over the shoulder 26 into the notch 25. The actuating lever is now in the lower position shown in dotted lines in FIG. 2 and it is impossible to rotate it in the other direction because of the shoulder 26 striking the side of the plunger 21. This means that the switch 19 stays in alarm-transmitting condition until an authorized person resets the apparatus. When the actuating lever is in a lower position, it is possible for an authorized person to give a general alarm by inserting his key through the aperture 37 to operate the key-locked switch 36. It can be seen, then, that, in order to operate the alarm switch, it is necessary for a person to deliberately break the glass window 16 and also to break the rod 39. The rod 39 is evident through the opening 23, so that the person who is thinking of turning in an alarm knows that he has to break this glass rod also. Resetting of the alarm box can only take place by swinging the enclosure 13 about its hinge axes provided by the wire element 38 after unlocking the lock 18, so that the lug 34 is free of the aperture 35 in the base 12. It, of course, requires a deliberate operation of the actuating lever to set off the alarm. Even after the window is broken (which might very well take place by accident), it is still necessary for a positive movement of the lever to take place.

When the enclosure 13 swings forwardly, the cam 24 moves along with it and that releases the plunger 21 and allows it to move to a non-alarm position. It is also possible then-to move the actuating handle into its upper position to which the spring 45 tends to make it return in any case. While resetting the switch 19, the authorized person may also replace the glass rod 39 which had been broken when the alarm was originally sent in. The operation of the switch 47 when the glass window is broken warns the personel of the fire station that the window has been broken accidently or by an unauthorized person so that someone can be sent out to investigate. Another interesting aspect of the present construction is that the glass plate can be replaced without setting off the alarm. Furthermore, depending upon the desires of the particular municipality or industrial organization using the alarm, they can select the various alarm features that they want and the manufacturing assembly simply omits those that are not wanted. In some installations it may be desirable to omit the frame 15, the glass window 16, and the hammer 17; in that case the alarm is set off simply by actuating the actuating lever 14. In some installations it may be desirable to leave out the general alarm switch 36. In a situation where the presence of vandals or unauthorized personel is not very likely, it may even be desirable not to use the glaSS rod 39.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

The invention having been thus' described, what is claimed as new and desired to secure by Letters Patent l'. A fire alarm system, comprising a. a housing containing an alarm switch,

b. a frame overlying the housing and containing a frangible glass window, the frame being hingedly attached to the housing at its lower portion and having a latch connecting it to the housing at its upper portion, the latch being held in engagement by the glass window and disengaged when the glass window is not present, so that the frame swings downwardly in front of the housing, and

c. means between the glass window and the housing for operating the said alarm switch, the said means being operable when the glass window is broken, but only by a deliberate operation by the person breaking the window.

2. A fire alarm system as recited in claim 1, wherein the actuating lever is mounted in the housing on a hinge shaft, wherein the lever is provided with a cam generally concentric with the shaft, which cam normally maintains the alarm switch in a non-alarm state,

3. A fire alarm system as recited in claim 2, wherein the alarm switch has an actuating plunger which is engaged by the said cam, and wherein the cam has a notch into which the plunger falls at a predetermined position of rotation of the lever and cam about the axis of the shaft, the notch being a shoulder that engages the plunger and prevents reverse rotation'of the lever and cam.

4. A fire alarm system as recited in claim 2, wherein the housing consists of a base and a cover hingedl connected together and fastened by a key-operate lock, so that opening the cover permits removal of the alarm switch plunger from the notch and the return of the lever to its normal position.

5. A fire alarm system as recited in claim 1, wherein the said meansis a swingable actuating lever, wherein a replaceable glass rod lies in the path of swing of the lever, so that the glass rod must be broken before the alarm switch is actuated.

0. means between the glass window and the housing for operating the said alarm switch, the said means being operable when the glass window is broken, but only by a deliberate operation by the person breaking the window, and a key-operated general alarm switch which is located in the housing and normally hidden by the means for operating the alarm switch, but is exposed when the said means is operated to activate the alarm switch.

Claims

1. A fire alarm system, comprising a. a housing containing an alarm switch, b. a frame overlying the housing and containing a frangible glass window, the frame being hingedly attached to the housing at its lower portion and having a latch connecting it to the housing at its upper portion, the latch being held in engagement by the glass window and disengaged when the glass window is not present, so that the frame swings downwardly in front of the housing, and c. means between the glass window and the housing for operating the said alarm switch, the said means being operable when the glass window is broken, but only by a deliberate operation by the person breaking the window.

2. A fire alarm system as recited in claim 1, wherein the actuating lever is mounted in the housing on a hinge shaft, wherein the lever is provided with a cam generally concentric with the shaft, which cam normally maintains the alarm switch in a non-alarm state.

3. A fire alarm system as recited in claim 2, wherein the alarm switch has an actuating plunger which is engaged by the said cam, and wherein the cam has a notch into which the plunger falls at a predetermined position of rotation of the lever and cam about the axis of the shaft, the notch being a shoulder that engages the plunger and prevents reverse rotation of the lever and cam.

4. A fire alarm system as recited in claim 2, wherein the housing consists of a base and a cover hingedly connected together and fastened by a key-operated lock, so that opening the cover permits removal of the alarm switch plunger from the notch and the return of the lever to its normal position.

5. A fire alarm system as recited in claim 1, wherein the said means is a swingable actuating lever, wherein a replaceable glass rod lies in the path of swing of the lever, so that the glass rod must be broken before the alarm switch is actuated.

6. A fire alarm system as recited in claim 1, wherein a frame-condition switch is mounted in the housing and is normally maintained in a non-signalling condition by the frame in a closed position, but changes to a signalling condition when the frame is in an open condition.