US3909814A - Detecting and control method and apparatus - Google Patents

Abstract

A method and apparatus are provided for detecting changes in physical phenomena and for subsequently controlling response devices in accordance with such detected changes. A sensor responsive to changes in physical phenomena such as temperature, pressure, density and the like caused, for example, during the occurence and progress of a fire, is operable to sense such changes in physical phenomena during different stages of progress and to sequentially actuate and control the operation of various response devices depending on the stage of progressive change of the physical phenomena.

Description

United StatesPatent 1 1 Eguchi [451 Sept. 30, 1975 1 DETECTING AND CONTROL METHOD AND APPARATUS [75] Inventor: Yoshihiro Eguchi, l-lino, Japan [73] Assignee: Hochiki Corporation, Tokyo, Japan [22] Filed: July 11, 1973 [21 Appl. No.: 378,347

[30] Foreign Application Priority Data July 14, 1972 Japan 47-69964 [52] U.S. Cl. 340/237 S; 337/42; 340/227.1; 340/420 [51] Int. C1. G08B 21/00 [58] Field of Search 340/222, 420, 228 R, 228 S, 340/227 R, 237 S, 237 R, 229, 220, 324 R; 73/15 R, 15 A; 337/38, 42, 49, 95, 96, 219,

[56] References Cited UNITED STATES PATENTS 1,597,403 8/1926 Cromie 340/227.l

2,699,480 l/1955 Armstrong 337/371 2,786,171 3/1957 Clark l l 337/95 3,052,788 9/1962 Peters 337/42 3,258,785 6/1966 Byrd 340/228R 3 376,425 4/1968 Kraus et a1 340/237R 2 541,539 11/1970 Trumble 340/227 3,634,839 1/1972 Vassil 340/237 S 3,636,540 1/1972 Harris 340/228 R FOREIGN PATENTS OR APPLICATIONS 923,182 4/1963 United Kingdom 340/237 R Primary ExaminerThomas B. Habeeker Attorney, Agent, or FirmFrank J. Jordan 5 7 ABSTRACT A method and apparatus are provided for detecting changes in physical phenomena and for subsequently controlling response devices in accordance with such detected changes. A sensor responsive to changes in physical phenomena such as temperature, pressure, density and the like caused, for example, during the occurence and progress of a fire, is operable to sense such changes in physical phenomena during different stages of progress and to sequentially actuate and control the operation of various response devices dcpending on the stage of progressive change of the physical phenomena.

ll Claims. 6 Drawing Figures -T\OONTROL DEVICE US. Patent Sept. 30,1975Sheet 1 of3 3,909,814

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l Z REsPoNsE DEVICE US. Patent Sept. 30,1975Sheet 2 of3 3,909,814

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LAMP/ I D SENSOR/ (RECEIVER -ooNTRo1 DEVICE RESPONSE DEVICES DETECTING AND CONTROL METHOD AND I APPARATUS DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method and apparatus detecting the occurrence of physical phenomena and for controlling the actuation of response devices according to the detected physical phenomena by using a single sensor device having a plurality of actuating points.

A variety of mechanisms or response devices may be provided which are operable in response to sensing actions of fire sensors according to particular stages of a spreading fire as sensed by such respective sensors. Assuming, for example, that a response device A is to be activated in the initial stage of a fire and another response device B is to be activated at a stage at which the fire has spread further. Two sensors, one having a higher sensitivity and the other having a lower sensitivity are required in order to control activation of both response devices sequentially. That is, the sensor having the higher sensitivity is used to activate and control the response device A and the sensor having the lower sensitivity is used to activate and control the response device B. Accordingly, since a plurality of response devices should be used for a corresponding number of objects, and hence substantially the same number of sensors are required, the necessity of having to provide such plurality of sensors becomes very expensive.

BRIEF DESCRIPTION OF THE INVENTION An object of the present invention is to provide a method and apparatus for detecting changes in physical phenomena caused for example by the occurrence and progressive advancement of a fire and to sequentially actuate and control various response devices according to the progressive advancement of the fire.

A further object of the present invention is to provide a method and apparatus which may be used for detecting fires and the like.

Another object of the present invention is to provide an inexpensive device or sensor for detecting Changes in a physical phenomena.

By way of example, a smoke detector or sensor may be provided which is operable to transmit a signal to a receiver when the detector or sensor senses a small amount of smoke to visually indicate on a display'window of the receiver the position or location where the detector or sensor is installed and to actuate an emergency alarm device along with a first group of response devices such as emergency doors and the like to be opened. When the fire spreads and a more dense smoke is detected by the detector or sensor a second group of response devices such as fire-doors, smoke-exhausting devices, smoke-blocking curtain walls, fire extinguishing apparatus and the like are actuated.

BRIEF EXPLANATION OF THE DRAWINGS The above and other objects and features of the present invention will become apparent from reading of the following description of preferred embodiments of the present invention with reference to the attached drawings', in which FIG. 1 shows schematically the construction of a preferred embodiment of a thermally responsive sensor suitable for use in the present invention;

FIG. 2 is similar to FIG. 1, showing another embodiment of a thermally responsive sensor;

FIG. 3 is a further embodiment showing a pressureresponsive sensor suitable for use in the present invention;

FIG. 4 shows a schematic circuit diagram of an embodiment of the present alarm showing a control device which utilizes any of the sensors shown in FIGS. 1 to 3 FIG. 5 is an embodiment of an alternate embodiment which utilizes a sensor of the ionization type which is responsive to changes in smoke density; and

FIG. 6 is still another embodiment of the present device using the same sensor as that used in FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, FIG. 1 to 3 show fire sensors of the temperature responsive type which are suitable for use in the present invention. In FIG. 1, abimetal strip 1 and an electrically conductiveresilient strip 2 are each supported at one end thereof by asupport 3 made of insulating material. On the opposite ends of thebimetal strip 1 and theresilient strip 2 there are providedelectric contacts 4 and 5 respectively which face each other. Another fixedcontact 6 is provided which also faces thecontact 5.Reference numeral 7 denotes a sensor casing or housing in which thebimetal strip 1 andresilient strip 2 are housed.

In operation, thebimetal strip 1 starts to bend upwardly when the ambient or surrounding temperature is raised, for example due to a fire in the surrounding area. When the temperature reaches a predetermined point, thecontact 4 of thebimetal strip 1 electrically contacts thecontact 5 on theresilient strip 2 so that a circuit is completed between terminals t, to t which are connected to thebimetal strip 1 and theresilient strip 2 respectively. As the surrounding temperature increases to a further and higher point due to the progress of the fire, thebimetal strip 1 bends upwardly to a larger extent, until theresilient strip 2 is ultimately urged upwardly to a position in which thecontact 5 on theresilient strip 2 contacts thefixed contact 6 to thereby close a circuit between the terminal t and a terminal connected to theresilient strip 2 and fixedcontact 6 respectively.

FIG. 2 shows a sensor similar to that shown in FIG. 1 except that a pair of bimetal switch units are utilized instead of a single bimetal switch unit as in the case of FIG. 1. In FIG. 2 a pair ofbimetal strips 10 and 11 are provided and eachbimetal strip 10, 11 has a different response to temperature change. Also provided are support strips 12 and 13 having contacts 16 and 17 which cooperate withcontacts 14 and 15 provided on thebimetal strips 10 and 11 respectively. The support strips Hand 13 in FIG. 2 correspond to theresilient strip 2 in FIG. 1. However, in the embodiment of FIG. 2 the support strips 12, 13 may not always be made of a resilient material. In the sensor in FIG. 2 as the ambient or surrounding temperature rises, thecontacts 14 and 16 first come into contact with each other and, as the temperature rises further thecontacts 15 and 16 then come into contact with each other to thereby sequentially first close a circuit between the terminals t and t and then subsequently to close a circuit between terminals t and t and vice versa.

'FIG. 3 shows a sensor employing adiaphragm 21. Thediaphragm 21 is electrically conductive and is provided with acontact 23 thereon and agas leakage orifice 22. Inthe sensor of the type shown in FIG. 3 the internal space of thesensor casing 7 is divided by the electricallyconductive diaphragm 21 into twochambers 7a and 7b and under normal conditions, the pressure in bothchambers 7a, 7b is maintained at an equal pressure level by theleakage orifice 22. However, when the ambient or surrounding temperature rises, for example upon the occurrence of a fire or the like, the pressure in thechamber 7b, which is more sensitive to the ambient or surrounding temperature than the chamber 7a, increases while the pressure in the chamber 7a which is thermally insulated from the ambient or surrounding temperature is not increased to such a large degree. As a result of this pressure differential, thediaphragm 21 is forced toward the chamber 7aand thus the circuit is closed as thecontact 23 on thediaphragm 21 contacts the contact on theresilient strip 2. As the temperature increases further, thediaphragm 21 is forced further into the chamber 7a, resulting in closing of a circuit between thecontact 5 and a fixedcontact 6.

In FIGS. 1 to 3, the operating levels and temperatures at which the respective contacts are actuated may be regulated or controlled by selecting the bimetals strips or diaphragm as the case may be, having the desired thermal response as well as by selecting the distances between the contacts to be mated.

By utilizing a sensor having two operating points as described above, a plurality of response devices or actuating devices having different properties can be controlled by the single sensor. FIG. 4 shows an example of the present system in which a plurality of response devices are controlled by a single sensor.

In FIG. 4, the reference character D denotes a sensor having two setting points or levels in which d, is a sensing switch unit of high sensitivity and d is a sensing switch unit of lower sensitivity than that of d,. L, is a relay coil adapted to cause contacts I, and l, to close upon closure of the switch unit d,, and L is a realy coil adapted to cause acontact 1 to close upon the closure of the switch (1,. R is a receiver, E, to E, are power sources, A is a lamp adapted to indicate the location in which the fire occurs and B is a bell or buzzer to serve as an alarm to indicate the occurrence of the fire. The contact I, is disposed in a circuit of a response device Z, to be controlled by the sensor D, and thecontact 1 is disposed in a circuit of another response device Z also to be controlled by the same sensor D.

In operation of the device in FIG. 4, assuming that the device utilizes a sensor D such as the previously described temperature responsive sensors, the high sensitivity switch unit d, of high sensitivity is first closed by the initial increase of the ambient temperature. Upon closure of the switch unit d,, an electric current flows through the coil L, to thereby close thecontact 1,. As a result, the lamp A of the receiver R is switched on to indicate the location in which the fire occurs and the hell or buzzer B connected in parallel to the lamp A is energized. Simultaneously, the contact I, is closed to actuate the response device Z,. The actuation of the response device Z, may include, for example, unlocking emergency doors and switching on an emergency broadcasting device to make it possible to broadcast an emergency announcement relating to the occurrence of the fire at any time thereafter. After the fire progresses and the ambient temperature is further raised accordingly, the switch unit d is closed. Upon the closure of the switch unit d an electric current flows through the coil L to close thecontact 1 thereof to thereby actuate the response device Z to be controlled at this stage of the fire. Since it is clear that the fire at this stage is significantly dangerous, the actuation of the response device Z may include shutting fire-proof doors and actuating a fire-extinguishing apparatus or the like.

In this manner, it is of course possible to control a number of response devices by providing more than three setting points each having different sensitivity levels in the sensor. Alternatively, sensors other than the temperature-responsive or pressure responsive type sensor may also be utilized in the present invention.

FIG. 5 shows an embodiment of the present invention in which an ionization type smoke sensor having a plurality of operating points or setting points is utilized. In FIG. 5 C, is an external chamber into which smoke may easily enter and the atmosphere in the chamber C, is ionized by a radioactive isotope, for example, such as A,, or the like. C is an internal chamber into which it is more difficult for smoke to enter as compared to the chamber C,, and the atmosphere in the chamber C is also ionized similarly to the chamber C,,. The chambers C, and C are connected in series and a DC. source E,, is applied thereacross. The ions in the chambers C,, C tend to move due to the applied voltage and thus a small amount of electric current (ion current) flows through the chambers C C When smoke enters the chamber C,, the voltage at a connecting point G between the two chambers C C is lowered to thereby block the movement of the ions, that is, the resistance of the chamber C, is increased by the pressure of smoke therin. This voltage drop is amplified by an amplification element F such as a field effect transistor. ZD,, ZD,, to ZD,, are Zener diodes, and the Zener voltages of these Zener diodes are selected so that the lowest Zener voltage occurs in Zener diode ZD,, and the Zener voltages are higher for the Zener diodes having the larger suffix with the highest being Zener diode ZD,,. S, to S, are switching elements such as thyristors or the like respectively and d,, to d, are diodes for blocking reverse current flow. L,, to L,, are relay coils, 1,, to l, are self-holding contacts for the respective relays, and l,, to l, and 1",, are contacts operated by the respective relays. E,, to E are power sources, H is a recovery key switch, A, a fire indicator lamp, B, an alarm generating device such as bell, buzzer or the like, r, to r,, resisters, R, a receiver, D a sensor and J a control device for controlling theresponse devices 2,, to Z,,.

In operation, when smoke enters the external chamber C,, the voltage at the junction G is lowered and thus a current flows into a base of the amplification element F thereby resulting in a larger current flow through an emitter-collector circuit of the amplification element F. Due to the larger current, the voltage of the cathodes of Zener Diodes ZD,, ZD,, and ZD,, is increased, and Zener diode ZD, which has the lowest Zener voltage is initially turned on. Upon the conduction of the Zener diode ZD,, the thyristor S, is turned on or triggered causing current to flow from the positive terminal of the power source E, through the normally closed switch H, through the thyristor 8,, through the diode d,, and through the relay coil L,, to the negative terminal of the power source E,,. As a result of the current flow through the coil L,,, the self-holdingcontact 1,, thereof and the contact I,, ganged therewith are closed to thereby energize the lamp A and ring the bell or buzzer B At the same time, the contact I ganged also therewith is closed to thereby actuate the response device Z such as an emergency broadcasting device or the like which should be actuated at the initial stage of the fire for guiding peoples to fire escapes. With the progress of the fire, a larger amount of smoke enters into the chamber C Consequently, the Zener diode ZD whose Zener voltage is higher than that of the Zener diode ZD becomes into a conductive state to thereby trigger the thyristor S so that a current flows from the positive terminal through thyristor S through diode d and through relay coil L to the negative terminal Accordingly, the relay coil L is actuated to thereby cause the self-holdingcontact 1 thereof to close and at the same time the contact l ganged therewith is also closed to actuate the response device Z which drives or actuates, for example, fireproof doors or the like. When the amount of smoke is further increased and the amount of smoke entering the external chamber C is increased accordingly, the Zener diode ZD becomes conductive to actuate the response device Z In this manner, it will be readily seen that a plurality of response devices Z to Z,, are actuated sequentially according to the stages of the fire.

FIG. 6 shows another embodiment using a smoke sensor similar to that used in FIG. 5. While the number of conductors connecting the receiver R and the sensor D to the response devices in the apparatus of FIG. 5 is increased with the increase of the number of the response devices, the number of conductors utilized in the device shown in FIG. 6 is only two irrespective of the number of the response devices. The reference symbols used in FIG. 5 are also used in PEG. 6 to indicate elements similar to those in FIG. 5. In addition, in FIG. 6, T and T are transistors, I) to D are diodes forming a full wave bridge rectifier, D to D, are diodes, R to R are risistors, VR and VlR are variable resistors, and f is a change over switch.

The positions of the respective switches and/or contacts are initially as shown in FIG. 6. When smoke enters the external ionization chamber C u and thus the electric potential at the junction G is lowered, the field effect transistor F is turned on and hence the transistor T is turned on. With the turning on of the transistor T the collector voltage thereof rises to thereby trigger the thyristor S through the diode D As a result, a circuit from the positive terminal of voltage source E in turn, through change over switch f, diode D diode D thyristor S diode D relay coil L and switch H and then to the negative terminal of power source E is completed and, due to the current flowing through the coil L a self-holding circuit thereof is completed by theclosed switch 1 of the same, the display lamp A is energized by the closed contact I interlocked with thecontact 1 to indicate the location where the fire occurs and the response device Z is actuated by theclosed contact 1 which is also interlocked with thecontact 1 Subsequently an operator switches the switch f manually to contact the pole thereof with the upper contact or alternatively, the same operation may be performed automatically by using the relay coil L As a result, a polarity of voltage applied on the conductor connecting the sensor D" to the receiver R by the power source E is reversed. However, because of the presence of the diode bridge D D the polarities of voltage applied to the circuits for the ionization chambers C and C are the same as those initially applied and thus a normal operation thereof is performed. At this time, however, since the thyristor S has been turned off due to the interruption of power supply caused during the operation of the switch f and since the transistor T is turned off after the operation of the switch f due to the reverse voltage applied, the thyristor S is per manently in an off state. When the fire progresses and a large amount of smoke enters the external ionization chamber C the potential at the junction G is considerably lowered. Accordingly the field effect transistor F is conducted more deeply resulting in a larger current flow and when the conduction of the transistor F reaches a predetermined level, the transistor T is turned on. Upon the turning on of the transistor T a trigger signal is supplied through the diode D to the thyristor S to trigger the latter so that a circuit is closed from the positive terminal of voltage source E through resistor r contact I diode D thyristor S diode D diode D relay coil L switch f and switch H in that order to the negative terminal of voltage source E causing the response device Z to be actuated. The setting points of operation of the re sponse devices Z and Z can be regulated by regulating the variable resistors VR and VR As described in detail hereinabove, according to the present invention, it is possible to control various response devices which are required to be actuated at any required stage or stages of the fire in accordance with the progressthereof. Heretofore, in order to control a plurality of response devices which are to be actuated at different stages, the corresponding number of sensors each having different sensitivity were provided at a commonplace because the conventional sensor has only one setting point for operation, so that the cost of installation has been very high. To the contrary, since the present invention makes it possible to use a single sensor to control any number of response devices at any desired situations, the cost of the installation can be substantially reduced. Furthermore, since the sensor of the present invention such as, for example, the bimetal type sensor, may be readily fabricated merely by increasing the number of the bimetal portions of a conventional sensor without changing any other components including the casing thereof, the economy thereof may be relatively improved with respect to conventional devices.

It should be noted that, although in performing the present method, only certain embodiments of the invention are shown and described in detail, the present invention is not limited thereto and various modifications of the present device and method will be apparent to those skilled in the act without departing from the scope of the present invention which is defined by the attached claims.

What is claimed is:

1. Apparatus for detecting changes in physical phenomena such as changes in smoke concentration and the like and for controlling response devices in accordance with said detected changes, comprising a sensor, said sensor including an ionization means operable to convert a change in smoke concentration into an electrical signal, said ionization means including a pair of chambers one of which is more susceptible to receiving smoke from the surrounding atmosphere than said other chamber, operable means within said sensor defining'a plurality of actuating points each responsive respectively to progressively increasing stages of change of said physical phenomena, said operable means including connecting means for connecting said chambers in series and applying a voltage source thereacross and amplification means between said chambers responsive to the change in resistance in said chambers caused by differences in smoke concentration in said chambers, a plurality of response devices corresponding respectively to each of said actuating points, said plurality of response devices being operable to provide appropriate response effects dependent on the progressively increasing stages of change of said physical phenomena, and actuating means activated by each of said plurality of actuating points for controlling the operation of said response devices corresponding to each of said actuating points, whereby particular response devices are progressively operable in appropriate response to progressively increasing stages of change of said physical phenomena.

2. Apparatus according toclaim 1 wherein said sensor includes a pair of transistors operably connectable to a plurality of diodes forming a full wave bridge rectifier, each of said transistors being operable depending on the magnitude of an amplification signal produced by said amplification means, a thyristor triggered by said diodes, a change over switch means effecting a change in the current flow path depending on which transistor is operated, and a plurality of variable resistors to vary the setting points of said response devices.

3. Apparatus according toclaim 1 wherein said ionization means is ionized by a radioactive isotope.

4. Apparatus according toclaim 1 wherein said amplification means is a field effect transistor.

5. Apparatus according toclaim 4 including a plurality of Zener diodes having progressively varying Zener voltages and a thyristor associated with each of said Zener diodes, whereby said Zener diodes are progressively operated by said amplification means to progressively trigger said thryristors in accordance with progressive change in said physical phenomena.

6. Apparatus according toclaim 1 wherein one of said response devices includes a receiver operable to indicate an initial sensed change of physical phenomena.

7. Apparatus according toclaim 6 wherein said receiver is operable to indicate the location where said initial sensed change of physical phenomena occurred.

8. Apparatus according toclaim 6 wherein said receiver includes an acoustic means operable to effect an audible indication of the initial sensed change of physical phenomena.

9. Apparatus according toclaim 6 wherein said'receiver includes a response means, said receiver being operable to control the actuation of said response means.

10. Apparatus according to claim 9 wherein said receiver includes a location indicator means, an acoustic means, and a response means, said location indicator means and acoustic means being actuated substantially simultaneously with the actuation of said response means.

11. Apparatus according to claim 10 wherein there are two conductors between said receiver and said sensor irrespective of the number of said response devices.

Claims (11)

1. Apparatus for detecting changes in physical phenomena such as changes in smoke concentration and the like and for controlling response devices in accordance with said detected changes, comprising a sensor, said sensor including an ionization means operable to convert a change in smoke concentration into an electrical signal, said ionization means includiNg a pair of chambers one of which is more susceptible to receiving smoke from the surrounding atmosphere than said other chamber, operable means within said sensor defining a plurality of actuating points each responsive respectively to progressively increasing stages of change of said physical phenomena, said operable means including connecting means for connecting said chambers in series and applying a voltage source thereacross and amplification means between said chambers responsive to the change in resistance in said chambers caused by differences in smoke concentration in said chambers, a plurality of response devices corresponding respectively to each of said actuating points, said plurality of response devices being operable to provide appropriate response effects dependent on the progressively increasing stages of change of said physical phenomena, and actuating means activated by each of said plurality of actuating points for controlling the operation of said response devices corresponding to each of said actuating points, whereby particular response devices are progressively operable in appropriate response to progressively increasing stages of change of said physical phenomena.

2. Apparatus according to claim 1 wherein said sensor includes a pair of transistors operably connectable to a plurality of diodes forming a full wave bridge rectifier, each of said transistors being operable depending on the magnitude of an amplification signal produced by said amplification means, a thyristor triggered by said diodes, a change over switch means effecting a change in the current flow path depending on which transistor is operated, and a plurality of variable resistors to vary the setting points of said response devices.

3. Apparatus according to claim 1 wherein said ionization means is ionized by a radioactive isotope.

4. Apparatus according to claim 1 wherein said amplification means is a field effect transistor.

5. Apparatus according to claim 4 including a plurality of Zener diodes having progressively varying Zener voltages and a thyristor associated with each of said Zener diodes, whereby said Zener diodes are progressively operated by said amplification means to progressively trigger said thryristors in accordance with progressive change in said physical phenomena.

6. Apparatus according to claim 1 wherein one of said response devices includes a receiver operable to indicate an initial sensed change of physical phenomena.

7. Apparatus according to claim 6 wherein said receiver is operable to indicate the location where said initial sensed change of physical phenomena occurred.

8. Apparatus according to claim 6 wherein said receiver includes an acoustic means operable to effect an audible indication of the initial sensed change of physical phenomena.

9. Apparatus according to claim 6 wherein said receiver includes a response means, said receiver being operable to control the actuation of said response means.

10. Apparatus according to claim 9 wherein said receiver includes a location indicator means, an acoustic means, and a response means, said location indicator means and acoustic means being actuated substantially simultaneously with the actuation of said response means.

11. Apparatus according to claim 10 wherein there are two conductors between said receiver and said sensor irrespective of the number of said response devices.

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