US3805257A - Combined fire and burglar alarm - Google Patents

Abstract

A self-powered combined burglar and fire alarm is provided employing a plurality of self-powered photoflash transmitter units that are selectively triggered into operation by burglar activity or by fire to produce a high intensity pulse of light. A centralized detector responds to the light pulse produced by anyone of these triggered units to annunciate the fire or the presence of the intruder.

Description

United StatesPatent [1 1 Litman et al.

4] COMBINEDIFIRE AND BURGLAR ALARM I [76] Inventors: Alan L. Litman, Hartwood Dr.,

Pittsburgh, Pa.; Norman C. Eisenstat, 716 Linden Ave., Pittsburgh, Pa. 15208; Don R. Horowitz, 5464 Darlington Rd., Pittsburgh, Pa. 15219 22 Filed: May 11, 1972 21 Appl. No.: 252,224

[52] US. Cl 340/219, 340/227.1, 340/303, 340/416 [51] Int. Cl. G08b 19/00 [58] Field ofSearch 340/219, 303, 227, 227.], 340/420, 416; 116/87, 107

[56] References Cited UNITED STATES PATENTS 3,699,569 10/1972 Lee ..340/227.1

[ Apr. 16, 1974 3,095,556 6/1963 Fuller 340/227.1 2,196,961 4/1940 Epstein 116/87' 1,838,144 12/1931 l-lolmes.... 340/227.1

11/1946 Padilla 340/227.[

Primary E.\'aminer John W. Caldwell Assistant Examiner-Marshall M. Curtis Attorney, Agent, or Firm-Paris, Haskell & Levine ABSTRACT A. self-powered combined-burglar and fire alarm is provided employing a plurality of self-powered photoflash transmitter units that are selectively triggered into operation by burglar activity or by fire to produce a high intensity pulse of light. A centralized detector responds to the light pulse produced by anyone of these triggered units to annunciate the fire or the presence of the intruder. I

7 Claims, 4 Drawing Figures moses-F FIG.1

FIG. 3

26 l? ALAR LIGHT LIGHT FLASH A FIG. u

LIGHT FLASH PHOTO CELL FLASH 1 COMBINED FIRE AND BURGLAR ALARM STATEMENT OF THE INVENTION This invention relates to combined burglar and fire alarm systems that are useful for inexpensively guarding the interior of buildings against unauthorized intrusion by burglars, as well as warning of the existance of fire.

RELATED APPLICATIONS In an earlier application of Alan L. Litman, Ser. No. 137,275, filed Apr. 26, 1971, now Pat. No. 3,714,647 there is provided a burglar alarm system employing individual photoflash light pulse transmitter units that are triggered by the unauthorized opening of a door or window to emit a high intensity light pulse. A plurality of such transmitters guard all doors and windows of the building; and in combination with a centralized light pulse detector and receiver, function to annunciate the presence of a burglar entering through any of such openings. In a preferred system, each such transmitter employs a disposable and inexpensive contact actuated pyrotechnic photoflash unit that is self-energizable and does not require an electrical battery or other power source. A complete burglar alarm system may therefore be provided employing a minimum of electrical wire and considerably less installation costs than alternate alarm systems.

SUMMARY OF THE INVENTION AND ADVANTAGES According to the present invention, there is provided a similar system employing a plurality of individual transmitter light pulse units but with each such unit incorporating an additional sensor that responds to fire or heat to trigger the unit. Thus each such transmitter responds to either the unauthorized entry or attempted entry by a burglar or, alternatively, responds to fire or heat to emit its high intensity light pulse. As in the earlier application, this light pulse is transmitted to a centralized light detector and receiver which is, in turn, coupled to operate suitable visual or audible signaling means at a police or fire station, or located elsewhere as might be desired.

Since it is customary in the construction of many buildings to provide dispersed doors and windows at opposite ends and at the sides, the corresponding network of transmitters spaced at all of said openings for burglar protection provides a rather. comprehensive dispersion of sensors for fire warning purposes also. Addition transmitter units may, of course, be used at locations where a window or door opening does not exist to provide fire protection alone at such locations.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of a light pulse transmitter unit interconnected to a window,

FIG. 2 is an enlarged sectional view illustrating de- I tails of a preferred transmitter unit, and

DESCRIPTION OF A PREFERRED EMBODIMENT As illustrated in FIGS. 1 and 2 the photo flash transmitter 10 is preferably a small, inexpensive, disposable unit that may be easily attached to a window frame 12' or door frame and easily connected by a short chain or cable 11 to the openable window 13, door or other access opening member. Any number of such units may be employed in a room or building since each unit is completely independent in operation from the others.

A preferred transmitter unit 10 as shown in FIG. 2 employs a two piece openable hollow molded plastic housing having a pivotable forward wallor door 14 and containing one or more single use, disposable photoflash bulbs 15 supported inside. The bulbs 15 are arranged to be triggered upon opening of the door 14 to transmit a high intensity light pulse radiated outwardly through the open door 14 and over a wide angle.

According to the invention, it is desired to employ highly reliable, inexpensive, and self-powered photoflash units having a relatively long shelf life. A multiple light flash unit of this type is presently sold by Sylvania Electric under the name MAGICUBE, having an advertised reliability of operation of 99.7 percent. This multiple unit includes four minatureflash lamps 15A, 15B, etc., interconnected in a box like configuration supported on a base 16. Each different flash unit is individually triggerable by displacing aseparate driving pin such as 17A. These units 15 emit light by combustion of zirconium inside of each bulb, and this combustion is initiated by a pyrotechnic impact ignitor incorporated within the unit for each bulb and actuated by minor displacement of the pin, such as 17A. No seperate electrical battery or other source of power is required. Each such flash element produces an illumination of approximately 2000 beam candle power seconds, with most of the energy being generated in a transient peaked pulse, of about 10 milliseconds in time duration.

In the preferred embodiment of FIG. 2, a. pair of such flash bulb units 15A and 15B are triggered simultaneously in response to either a burglar entering the .door or window or alternatively in the event of fire or heat. This operation is as follows:

The pivotable door 14 of the housing 10 is mounted for rotation on shaft 18A and is normally urged by a compressed spring to rotate or pivot in a clockwise direction in FIG. 2. Upon opening of this door, a lower portion of the door 18, or an extension thereof, moves upwardly and strikes both of the downwardly projecting pins 17A and 17B, thereby igniting both of the light flash units 15A and 15B together. The combined light pulses from both bulbs is radiated outwardly through the open door in the housing.

The door 14 is normally maintained in the closed position shown by the presence of a heat fusible plug 20 of conical shape, as shown. This plug 20 is inserted into an opening provided in the base of the transmitter housing 10 and is accommodated as a door stop between the lower end 18 of the pivotable door 14 and a fixed projecting portion 21 extending inside of the housing, as shown. This fusible plug 20 also supports the pull chain 11.

It is believed now apparent that upon removal of the fusible plug 20, by either pulling downwardly on the chain 11 or by melting of the fusible plug 20 in response to heat, the door 14 is released; and under the force of the compressed spring 19, opens to trigger the flash light bulbs as discussed above.

As discussed in said earlier patent application of Alan L. Litman, a series of such transmitter units are located and installed at various doors and windows to provide complete protection of a building against the entry or attempted entry'of unauthorized persons. According to the present invention still additional transmitters may also be installed at locations where no doors or windows exist to provide fire protection alone at such locations.

All of these transmitters are preferably self-powered and require no electrical wiring or other external power source.

In optical communication with each transmitter, or group of transmitters, is a centralized receiver alarm circuit as schematically illustrated in FIG. 3. This receiver includes a light sensitive member such as a photocell 25, an amplifier switching circuit 26, and an alarm 27. The receiver responds to the generation of a transient light pulse from any one of the photoflash transmitters to energize the audible or visible signal alarm 27, warning of an unauthorized violation of the integrity of the guarded premises or of the existance of heat or fire at any of the transmitter locations. The amplifier switching circuits 26 in the receiver contains circuitry rendering the receiver insensitive to ambient lighting conditions, such as sunlight, or to changes in such ambient conditions, and preferred circuitry for this purpose is disclosed in said earlier Litman application.

If it is desired to completely eliminate dependence upon external electrical power wiring,'the centralized receiver may be powered by battery or by other selfcontained source. Alternatively, it may be designed to use conventional AC electrical power, or DC power as is available in certain countries.

Where the premises to be protected are comprised of a series of partitioned areas, such as separated rooms, a receiver of this type may be located in each such room. Alternatively, a series of light pulse producing relays may be employed to optically interconnect the different partitioned locations together in a concatenated light pulse chain using only one or more centralized alarms or warning systems. A light pulse producing relay circuit of this type is schematically shown in FIG. 4, and specific circuitry is shown in the earlier Litman application. Such a device is similar to the alarm circuit of FIG. 3, but instead of having the receiver energize an alarm 27, the responding amplifier signal is employed to electrically energize a flashbulb socket and bulb 29. In operation, a series of such light relays are located in optical communications with one another from room-to-room, and with various'of these relays in position to observe the transmitters. A light pulse produced by any one of the transmitters anywhere in the optical chain, is propagated to its related light relay. This relay thereupon produces a sympathetic light pulse that is radiated to the next relay, and so forth down the chain, until an alarm operating receiver is energized. By proper placement of such light relays, all locations of a building, on all floors may be placed in optical communication with one another.

The transmitter units may also be electrically or mechanically connected with other types of sensors; or other alarm systems may be coupled into the optical system. For example, foot or pressure operated sensor switches may be connected to energize the receivers or light pulse producing relays. Similarly smoke detectors or pressure detectors may also be coupled into the sys tern.

The signal alarm circuits may be of visual or audible types, or may be coupled by telephone wires, or radio beams to provide a warning signal at a location remote from the optical system. i

As also discussed in said earlier application, the light flashing units are preferably inexpensive, single use, expendable, self-powered devices that must be replaced after being triggered. However, multiple photoflashing units may be employed. For a secrecy system, infra-red, ultra-violet, or other filters may be used over the transmitters, to permit only light wavelengths to be transmitted that are not visible to the burglar yet detectable by properly designed receivers.

The fusible plug 20 is preferably molded in a shape and of low melting point metal alloys as to partially melt and break apart at temperature close to 136 degrees F. A preferred construction that reliably provides the desired break apart action comprises molding the member with a central hub and two radial spokes 30 and a discontinuous outer periphery.

Many other changes and variations may be made by those skilled in this art and this invention should ac cordingly be limited only by the following claims:

We claim:

1. In a combined burglar and fire alarm system,

a light pulse generator including,

operating means for causing said generator to emit a light pulse,

means coupled to said operating means and responsive to movement to actuate said operating means, and

means coupled to said operating means and responsive to the presence of heat to actuate said operating means,

and a light pulse detector spaced from and in optical communication with said generator to produce an alarm upon detection of said light pulse.

2. In the system of claim 1', a plurality of such generators spaced apart from one another and all in optical communication with said detector.

3. In the system of claim 1, each of said generators including a photoflash unit, said operating means including a springdn'ven member for triggering said photoflash unit and said heat responsive means including a heat fusible element.

4. In the system of claim 3, said photoflash units being self-powered and contact operated to ignite a pyrotechnic flash material.

5. In the system of claim 1, additional means for sensing other conditions and coupled to said system.

6. In the system of claim 1, said generator operating means including a spring biased triggering member, said heat responsive means including a heat fusible element positioned as a stop to prevent spring actuated movement of said triggering member, and said means responsive to movement interconnecting said fusible element for removal from said stop position in response to movement of the member to be protected, whereby said triggering member is selectively released in response to sufficient heat applied to the fusible element and in response to movement of the member to be prospring biased triggering member.

Claims (7)

1. In a combined burglar and fire alarm system, a light pulse generator including, operating means for causing said generator to emit a light pulse, means coupled to said operating means and responsive to movement to actuate said operating means, and means coupled to said operating means and responsive to the presence of heat to actuate said operating means, and a light pulse detector spaced from and in optical communication with said generator to produce an alarm upon detection of said light pulse.

2. In the system of claim 1, a plurality of such generators spaced apart from one another and all in optical communication with said detector.

3. In the system of claim 1, each of said generators including a photoflash unit, said operating means including a spring driven member for triggering said photoflash unit and said heat responsive means including a heat fusible element.

4. In the system of claim 3, said photoflash units being self-powered and contact operated to ignite a pyrotechnic flash material.

5. In the system of claim 1, additional means for sensing other conditions and coupled to said system.

6. In the system of claim 1, said generator operating means including a spring biased triggering member, said heat responsive means including a heat fusible element positioned as a stop to prevent spring actuated movement of said triggering member, and said means responsive to movement interconnecting said fusible element for removal from said stop position in response to movement of the member to be protected, whereby said triggering member is selectively released in response to sufficient heat applied to the fusible element and in response to movement of the member to be protected.

7. In the system of claim 6, said light pulse generator comprising a self-powered mechanical contact actuated photoflash unit operated upon contact by said spring biased triggering member.

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