US3603403A

US3603403A - Automatic fire extinguishing apparatus

Info

Publication number: US3603403A
Application number: US851624A
Authority: US
Inventors: Elwood R Horwinski
Original assignee: Lewis Engineering Co
Current assignee: Lewis Engineering Co
Priority date: 1969-08-20
Filing date: 1969-08-20
Publication date: 1971-09-07
Anticipated expiration: 1988-09-07

Abstract

Automatic Fire Extinguishing Apparatus which is independent of commercial utilities such as water supply, electrical service and the like, comprising a local pressurized source of extinguishing fluid and a plurality of flexible distribution hoses having sets of nozzles, said hoses also having detecting electrical conductors which respond to heat and which are connected to responsive power equipment controlling valves for releasing the extinguishing fluid under conditions of fire. The conductors and responsive power equipment include heat insulation providing a special delay action by which normal changes in ambient temperature have no effect whereas a quick rise in ambient temperature causes quick response of the extinguisher.

Description

United States Patent [72] Inventor Elwood R. I-Iorwinski Chesire, Conn. [21] Appl. No. 851,624 [22] Filed Aug. 20, 1969 [45] Patented Sept. 7, 1971 [73] Assignee Lewis Engineering Company Naugatuck, Conn.

[54] AUTOMATIC FIRE EXTINGUISHING APPARATUS 15 Claims, 7 Drawing Figs.

[52] 11.8. CI 169/5 [51 1 Int. Cl A62c 35/00 [50] FieldofSearch 169/1,2,5, 16, 19,23,27,42, l B;138/111,104,33, 12 132,133,138,149

[56] References Cited UNITED STATES PATENTS 2,308,342 1/1943 Wilkinson et a1. 138/133 2,815,818 12/1957 Douglass 169/2 FOREIGN PATENTS 489,489 7/1938 Great Britain 169/23 936,302 9/1963 Great Britain 169/23 Primary Examiner-M. Henson Wood, .lr. Assistant Examiner-Edwin D. Grant Attorney-H. Gibner Lehmann ABSTRACT: Automatic Fire Extinguishing Apparatus which is independent of commercial utilities such as water supply, electrical service and the like, comprising a local pressurized source of extinguishing fluid and a plurality of flexible distribution hoses having sets of nozzles, said hoses also having detecting electrical conductors which respond to heat and which are connected to responsive power equipment controlling valves for releasing the extinguishing fluid under conditions of fire. The conductors and responsive power equipment include heat insulation providing a special delay action by which normal changes in ambient temperature have no effect whereas a quick rise in ambient temperature causes quick response of the extinguisher.

PATENTEUSEP Han 3.s03;403

SHEEI 1 OF 2 INVENTOR.

Elwood R. Hor'wins\ l AGENT PATENTED SEP 7 ISII SHEET 2 OF 2 mvemon Elwood. R.Hovw(.nski J T on 0m AGENT TRIGGER AUTOMATIC FIRE EXTINGUISIIING APPARATUS CROSS- REFERENCES TO RELATED APPLICATIONS l. Copending application of Elwood R. Horwinski, Ser. No. 755,203 filed Aug. 26, 1968, entitled Tamperproof Cable and Detection System and having common ownership with the present application.

-2. Copending application of Conrad S. Ham et al., Ser. No. 780,931, filed Oct. 28, 1968, entitled Printed-Circuit Type Security Apparatus for Protecting Areas and having common ownership with the present application.

3. Copending application of Elwood R. Horwinski, Ser. No. 761,725 filed Sept. 23, 1968, entitled Area Security Apparatus and having common ownership with the present application.

4. Copending application of Elwood R. Horwinski, Ser. No. 777,397 filed Nov. 20, 1968, entitled Area Security System Comprising Strain and Heat Responsive Network and having common ownership with the present application.

5. Copending application of Elwood R. I-Iorwinski, Ser. No. 81 1,685, filed Mar. 3, 1969, entitled Electrical Apparatus and Method for Monitoring Conditions" and having common ownership with the present application.

6. Copending application of Elwood R. Horwinski, Ser. No. 790,784, filed Jan. 13, 1969, entitled Safety Cable and having common ownership with the present application.

BACKGROUND This invention relates to automatic fire extinguishing systems. Heretofore systems of the kind indicated, which were independent of commercial utilities such as water, electricity etc. have been proposed and produced. While these systems were operative under certain given conditions they lacked sufficient sensitivity of response to fire while remaining dormant or inoperative for normal variations in the ambient temperature.

SUMMARY The above drawbacks of prior fire extinguisher systems are obviated by the present invention, one object being the provi- 'sion of an improved, wholly self-contained extinguisher which is independent of commercial utilities and which has an especially sensitive response to fire conditions while being relatively insensitive to normal variations in ambient temperature. This is accomplished by a novel combination comprising a local pressurized source of extinguishing liquid connected with flexible, orificed distribution hoses through valves which are electrically operated. The hoses have detecting conductors responding to heat and connected with power actuators for the valves, said actuators including electrical bridges. Certain conductors are provided with heat insulation to cause unbalanced the bridge and opening of the valves for rapid rises in ambient temperature, while maintaining a bridge balance and closed valve condition for normal, slow changes in ambient temperature. Where the extinguishing fluid is carbon dioxide, the orifices along the distribution hoses can be normally open. Those orifices which are not near heat will quickly freeze closed, when they are of small size due to evaporative cooling whereby only orifices in the vicinity of the fire where they are heated will remain operative to discharge the C Another object of the invention is to provide an improved fire extinguisher system as above set forth, wherein automatic shut-off of the extinguishing fluid is effected in the case of small fires which are quickly put out, and wherein a nonreversible extinguishing action occurs in the case of large fires which are [10! quickly put out.

Other objects and advantages of the invention reside in the provision of improved distribution hose constructions for a system .as characterized above, improved sensing conductor organizations in the distribution hoses, and in the provision of an extinguishing apparatus of the kind indicated, which is especially simple and foolproof, relatively economical, reliable in its operation, and adaptable to a wide variety of situations.

Still other features and advantages will hereinafter appear.

in the drawings:

FIG. 1 is a fragmentary perspective view of an automatic, self-contained extinguishing apparatus as provided by the invention.

FIG. 2 is a fragmentary top plan view of the apparatus, showing one form of distribution hose construction. 1

FIG. 3 is a diagrammatic representation of a building structure having incorporated in it the extinguishing apparatus.

FIG. 4 is a circuit diagram of an electrical control and indicator or signal unit as incorporated in the apparatus.

FIG. 5 is an enlarged fragmentary side elevation of a portion of a distribution hose and sensing conductors incorporated therein. v

FIG. 6 is an end elevational view of a connector fitting and nozzle adapted to join together two hose lines or sections.

FIG. 7 is a diagrammatic showing of a solid state trigger which is substitutable for a corresponding trigger portion of the circuit ofFlG. 4. 7

Referring first to FIGS. 1-3, the improved fire extinguisher apparatus as shown thereinembraces basically a plurality of hose lines 10 (here shown as six in number) which are connected to electrically controlled fluid valves 12 mounted on a manifold or distribution box 14 which latter is carried in an outer container or casing 16. The manifold 14 communicates with an inner container or cylinder 18 containing carbon dioxide gas under high pressure. One of the fluid distribution lines is diagrammatically illustrated in FIG. 2, said line comprising a plurality of hose sections 20 which are joined together by couplings or fittings 22 provided with nozzles or orifices 24. An end fitting 26, also having orifices 24, is provided on one of the hose sections 20.

In FIG. 2 only one of the hose lines 20 is illustrated, it'being understood that a plurality of such lines is connected to the CO cylinder 18. Although six such lines are illustrated, it will be understood that either a greater or a lesser number may be utilized, depending on installation requirements.

The hose lines 10 are flexible and may be of various lengths, depending on the number of sections 20 which are utilized. In FIG. 3 there is illustrated a building structure 28 which. is equipped with the fire extinguisher system of the invention. The structure 28 is shown as having rooms or

storage areas

30, 32 and 34 in which are disposed the lines 10 of the extinguisher, arranged in a manner considered most efiective, depending on the material being stored or the equipment being utilized.

In accordance with the present invention, each of the hoses 10 comprises not only a conduit or passage for fluid or liquid, but also electrical detecting or sensing conductors which respond selectively to a rapid rise of ambient temperature by operating the associated electrically controlled valve, thereby to effect a discharge of the extinguishing fluid through the hose line. The sets of sensing conductors are respectively con.- nected preferably with a plurality of bridge circuits (one for each hose line) which in turn control the electric valves, 1 2 carried by the manifold 14.

Considering FIG. 4 there is diagrammatically illustrateda hose 10 comprising a flexible conduit 36 which is preferably of spiral wound metal. Surrounding and wound about the conduit 36 are nickel, sensing conductors 3,8, 40 and lead or equivalent low-melting

point sensing conductors

42, 44. The sensing

conductors

38, 40, 42 and 44 are shown as connected respectively in the four legs of l a bridge circuit in such a manner that melting of the lead conductors will unbalance the bridge, or that unequal changes in the resistance of the nickel conductors will likewise unbalance the bridge. Such unequal changes of resistance can occur in response to a rapid rise ambient temperature as from a conflagration whereas the relative resistence values will not change for gradual changes of temperature such as normally occur due to weather and like conditions.

In effecting this, one of the nickel conductors (that indicated at is provided with a heat-insulating jacket 46 whereby it will not respond quickly to sudden large changes in temperature as from a fire whereas it will gradually change in temperature in keeping with changing weather or heating conditions or the like.

The bridge circuit is designated generally by the numeral 48, said circuit comprising a ground 50 connected by a wire 52 to the negative terminal of a battery 54. The positive terminal of the battery 54 is connected through a switch 56 to a wire 58 comprising one corner of the bridge. THe opposite comer" of the bridge 48 comprises a wire 60 which is connected with the ground 50. The nickel and lead sensing conductors are connected with

corner junctures

62, and 66. The

junctions

64 and 68 are connected with a galvanometer type instrument 70 which controls a movable shutter 72 having an aperture 74 in it. Adjacent the movable shutter 72 is an incandescent electric lamp 76 connected by wires 78, 80 and a resistor 82 to the battery 54. Closing of the switch 56 will ac cordingly effect illumination ofthe lamp 76.

The bridge legs have

adjustable resistors

84, 86, 88 and 90 connected respectively with the

conductors

42, 38, 40 and 44 whereby each bridge leg constitutes a complete circuit, including certain of the sensing conductors. The battery ground 50 is connected by a wire 60 to the bridge juncture 66, and the bridge juncture 62 is connected by the wire 58 to the switch 56. Accordingly, the bridge is energized from the battery 54 and may be placed in balance by suitable adjustment of the adjustable resistors.

In conjunction with the galvanometer 70, lamp 76 and movable shutter 72 there is provided a phototransistor or light sensitive cell 91 of the transistor type, having a base 92, a collector 94 and an emitter 96. The base 92 is connected through a resistor 98 and wire 100 with the positive supply wires 80 and 58 from the battery 56. The emitter 96 is connected by a wire 102 to the bridge juncture 62 which is in turn connected with the positive supply wire of the battery 56, and also connected by a wire 104 to a relay coil 106 which is in turn connected to an emitter 108 of a power transistor 110 whose base 112 is connected by wire 114 to the collector of the light sensitive cell 91. A resistor 116 connects the base 1 12 of the power transistor to the wire 104, said base being also connected througha resistor 118 and wire 120 to the collector 122 of the transistor 110. The wire 120 to the to the bridge juncture 66 which goes to the negative supply wire from the battery 56.

' The relay coil 106 controls

moveable contacts

124, 126, the latter being a holding contact engageable with a stationary contact 128 connected to the transistor emitter 108. The movable contact 126 is connected through a switch 130 to the collector 122.

The movable relay contact 124 connects through a wire 132 with a battery 134 which is connected to a switch 136 for controlling a signal or bell 138. The bell 138 is connected by a wire 140 to the stationary contact 142 which is cooperable with the relay contact 124.

In addition to the signal 138, a valve circuit control is effected by connecting to the wires 132 and 140 a valve coil 144 and battery 146.

Operation of the circuit of FIG. 4 is as follows: With the bridge balanced, the shutter 72 will be centralized and light from the lamp 76 will strike the light sensitive cell 91. This effects a conductive path between the collector and

emitter

94, 96 of the cell 91, thereby effecting a clamping action between the base 112 and emitter 108 of the transistor 110. In other words, the effect of light striking the cell 91 is such that no appreciable voltage or potential difference exists between the base 112 and emitter 108 of the power transistor 110. However, when the shutter 72 deflects to one side or the other due tounbalance of the bridge resulting from shorting, breaking, melting or resistance changes of any sensing wire or wires 38,

terminating the conductive path between the collector and

emitter

94, 96. The clamping action thus ceases, and voltage can now exist across the resister 116, meaning that a potential will exist between the base 112 and the collector 108 of the power transistor 110. Such voltage will render the transistor 110 conducting whereby the relay coil 106 will be energized by current flowing through the collector and emitter.

The result of this is that the relay coil 106, being energized, will actuate the

relay contacts

124, 126. If the relay contact 126 is in the nature of a holding contact, it will maintain the relay energized regardless of shutting off of the transistor 1 10. The

relay contacts

124, 126 will effect energization ofthe hell 138 and actuation of the electric valves 144, sounding an alarm and indicating that the bridge has been unbalanced, as by alteration of the continuity or resistance of the

wires

38, 40, 42 or 44. Thus, according to the invention, the hose 10 can respond to excessive heat by a melting of wires or changing of resistance, which wires as later explained are especially arranged to monitor these conditions.

Opening of the electric valve 144 will cause the CO from the container 18 to flow through the designated hose 10 and out of the nozzles thereof. Those nozzles which are not close to the heat will quickly freeze over and close automatically due to the small size and due to the evaporative cooling. The nozzles which are near the heat will not freeze over because they are warmed. Instead they will discharge the CO for the purpose of extinguishing the fire.

In the event that the holding

contacts

126, 128 of the relay coil 106 are not utilized but instead are rendered inoperative, an automatic shutting off of the electric valve 144 can occur whenever a balance is restored in the bridge. This can happen if none of the lead conductors has melted, and if the tire is quickly extinguished whereby the temperature of the noninsulated nickel sensing conductor 38 drops to normal. However, if the fire is of considerable magnitude, sufficient to melt the

lead conductors

32, 44, then there can be no reversible action of the bridge to restore the balance. In such case the absence of the holding

contacts

126, 128 will be of no significance since the bridge will remain permanently unbalanced, thus having the same effect as ifthe relay had holding contacts and remained closed once it was actuated by the bridge unbalance.

While FIG. 4 illustrates one specific type of bridge circuit and valve control, it will be understood that the invention is not limited to such arrangement, since others are possible without departing from the spirit of the invention.

A bridge circuit similar to that of FIG. 4, is illustrated and described in the copending application of Elwood R. Horwinski, Ser. No. 755,203 filed Aug. 26, I968 and entitled Tamperproof Cable and Detection System.

It will be understood that the electrically operated valve 144 of FIG. 4 may comprise either of the valves 12 shown in FIGS. 1 and 2, and that for each electrically operated valve and hose line there will he a corresponding bridge circuit with sensing conductors as illustrated in FIG. 4.

In place of the trigger device comprising the galvanometer 70, mirror 72, lamp 74 and phototransistor 91, a fully solidstate trigger may be employed. In FIG. 7 such a solid state trigger is illustrated, having terminals A, B, C, D E and F for connection to the correspondingly lettered terminals in FIG. 4. With such substitution the

devices

70, 72, 76, 82 and 91 will be removed from the circuit.

An advantageous hose line construction as provided by the invention is illustrated in FIGS. 4, 5 and 6. The hose line 20 shown in FIG. 5 comprises the spiral metal conduit 36 which may be of well-known construction, said conduit having wrapped around it the nickel sensing conductor 40 with its heat insulating jacket 46. The conductor 40 may be disposed in the helical groove of the metal conduit 36, as shown. Wrapped over the conduit 36 and conductor 40 is a spiralwrap ribbon 148 of insulating plastic. Around the wrap 148 is a second spiral wrap 150 of plastic ribbon, having adhered to it meltable foil strips constituting the

lead conductors

42, 44 AP urn A A Inn-1003'"- 8.;I'nl riklunn 1:1 In

placed around the ribbon 150 and foil strips 42, 44, thereby to cover the strips with an insulating layer. Around the spiral wrap 152 there is a wire braid wrap 154 which contains the nickel sensing conductor 38, said conductor having enamel or equivalent insulation whereby it does not make electrical contact with the remaining wires of the braid. Surrounding the braid 154 is an outer insulating jacket 156 of extruded plastic.

The

conductors

40, 42, 44 and 38 may be brought out to a pronged electrical fitting 158 at one end of a section of the hose line, such end being provided with a threaded end fitting 160. A companion section of hose line 20 illustrated in FIG. 5 may also have an end fitting 160 of a similar type, as well as a socket-type electrical fitting 162 which is cooperable with the fitting 158 for the purpose of providing continuity of the circuits of the sensing wires.

The hose sections 20 may be joined by a fitting or coupling 164 having turnable, internally threaded collars 166 adapted to thread onto the short nipple portions 168 of the end fittings 160. The hose coupling 164 can have one or more nozzles 170, two such nozzles being illustrated as in FIG. 6.

The above organization has a number of advantages. Hose lines of any practical length may be readily assembled by the use of longer or shorter sections which are coupled together by the fittings 164. Discharge nozzles may be located at strategic points by selecting suitable lengths of said hose sections; or a number of nozzle fittings may be joined to each other by use of suitable short nipples whereby any juncture between two hose sections 20 may have four, six or more nozzles, directed in different directions.

The use of the heat insulation 46 on the nickel sensing conductor 40 and the location of said conductor closely adjacent the metal conduit 36 and removed inwardly from the outer layers of the hose assemblage results in an advantageous delay in temperature changes of this wire. Accordingly, the nickel wire 38 will respond more rapidly than the wire 40 to sudden changes in ambient temperature, such as may be occasioned by a conflagration, thereby resulting in an unbalance of the bridge circuit and actuation of the associated electric valve. However, when gradual changes in ambient temperature occur, the

nickel conductors

38 and 40 will substantially simultaneously change their temperature and resistance whereby the balance of the associated bridge circuit will not be disturbed. Accordingly, the system will respond rapidly to fire conditions, but will not react at all to normal changes in ambient temperatures such as those occasioned by weather, heating conditionsin the building, and the like.

It will now be seen from the foregoing that I have provided a novel and improved automatic fire extinguishing system which is extremely sensitive to rapid, appreciable changes in temperature. Relatively slight changes in the resistance of the nickel wire 38 with respect to the resistance to the wire 40 can cause an unbalance of the bridge, whereby a sensitive response is had to fire conditions. However, in spite of such sensitive response, the apparatus will not be set off due to normal changes of ambient temperature, as already explained above. For small conflagrations involving unbalance of the bridge only by virtue of response of the nickel conductors, an automatic shut-off of the extinguishing fluid can occur when the fire has been extinguished and the bridge restored to balance by virtue of the nickel conductors being restored to their normal resistance values (provided that no holding contacts are employed in the system, such as the contacts 126, 128).

Referring again to FIG. 1, the container 16 may house the bell or signal alarm 138 and may also have a signal light 172 energized simultaneously with the bell 138. The bridge circuits associated with the hoses 10 may be housed in the container 16, in a suitable casing such as indicated at 174, and the various batteries and a charging unit are indicated as housed in a separate container 176. It will be understood that the apparatus as above set forth is independent of commercial utilities such as water supply, commercial electric power and the like. The apparatus is relatively simple, and is reliable and foolproof in its operation.

Variations and modifications are possible without departing from the spirit of the invention.

I claim:

l. A combined fire detector and extinguisher hose comprising, in combination:

a. a hose line adapted to carry an extinguishing fluid,

b. a wire wrap surrounding said hose line,

c. said wrap comprising a plurality of electrical conductors insulated from each other,

d. one of said conductors having a high and significant temperature coefficient of resistance greater than copper, thereby adapting it for use as a temperature-responsive sensor.

2. A combined fire detector and extinguisher hose comprising, in combination:

a. a hose line adapted to carry an extinguishing fluid,

b. a wire wrap surrounding said hose line,

(1. one of said conductors having a high and significant temperature coefficient of resistance greater than copper,

thereby adapting it for use as a temperature-responsive sensor,

a plurality of nozzles connected in said hose line to receive extinguishing fluid therefrom and to discharge the same to the surrounding area,

f. said nozzles having orifices sufficiently small to enable a discharging liquid to become frozen in it at temperatures caused by evaporation in a range considerably below ambient. I r

3. A hose as in claim 2, and further including: 7

a separable hose connector fitting carrying one of said nozzles and detachably connecting the same to separate lengths of said hose line, and

b. separable electrical connector fittings for detachably connecting the conductors of said lengths at a location adjacent said one hose connector fitting.

4. A combined fire detector and extinguisher hose comprising, in combination:

a. a hose line adapted to carry an extinguishing fluid,

b. a wire wrap surrounding said hose line,

0. said wrap comprising a plurality of electrical conductors insulated from each other,

d. one of said conductors having a high and significant temperature coefficient of resistance greater than copper thereby adapting it for use as a temperature-responsive sensor,

e. two of the conductors of high temperature coefficient of resistance have different responses to changes in ambient temperature, one of said two conductors having heat insulation surrounding it to render it relatively poorly responsive to surrounding heat and the other of said two conductors being relatively readily responsive to surrounding heat.

. A hose as in claim 4, wherein:

. said other conductor of high temperature coefficient of resistance surrounds the said one conductor in spaced relation thereto.

6. A hose as in claim 5, wherein:

a. the hose line comprises a spiral-wound flexible metal conduit having a helical external groove,

b. said one conductor of high temperature coefficient of resistance having an insulating jacket and being wound in said external groove,

c. a spiral wrap of insulation surrounding said metal conduit and one conductor,

d. said other conductor of high temperature coefficient of resistance being wound around and external to said spiral wrap.

7. A combined fire detector and extinguisher hose comprising in combination:

a. a hose line adapted to carry an extinguishing fluid,

b. a wire wrap surroundin said hose line.

d. one of said conductors having a high and significant temperature coefficient of resistance greater than copper, thereby adapting it for use as a temperature-responsive sensor,

. the conductors of high temperature coefficient comprise nickel,

othcr conductors of said sheath being constituted of lowmclting point metal.

A hose as in claim 7, wherein:

. two of the conductors of high temperature coefficient of resistance have different responses to changes in ambient temperature,

b. one of said two conductors having heat insulation surrounding it to render it relatively poorly responsive to surrounding heat and c. the other of said two conductors being relatively readily responsive to surrounding heat,

d. said other conductor of high temperature coefficient of resistance surrounds the said one conductor in spaced relation thereto,

e. said low melting point conductors being disposed between said two conductors of high temperature coefficient of resistance.

9. A hose as in claim 8, wherein:

d. said other conductor of high temperature coefficient of resistance being wound around and external to said spiral wrap,

e. said conductors of low melting point being carried by said spiral wrap of insulation.

10. A hose as in claim 2, and further including:

a. a supply of fire-extinguishing fluid connected to one end of said hose line,

b. a valve controlling the flow of fluid from said supply to the hose line,

c. an electric actuator for said valve, and

(1. means for delaying the temperature change of one of said two high temperature coefficient conductors when changes in ambient temperature occur, and

e. means connected to said high-temperature coefficient conductors, responding to a rapid change in the resistance of only one of said conductors due to a rapid change in ambient temperature surrounding said conductors, for activating said actuator to open the valve whereby extinguishing fluid'will be discharged through said hose line.

11. Apparatus as in claim 10, wherein:

a. the means responsive to rapid change in the resistance of one of the high-temperature coefficient conductors comprises a bridge circuit connected to said valve actuator and having said conductors in its legs.

12. Apparatus as in claim 10, wherein:

a. the means for delaying the temperature change comprises heat insulation surrounding said one high-temperature coefficient conductor.

13. Apparatus as in claim 12, wherein:

a. said other conductor is wrapped around the hose line in spaced relation thereto,

b. said one conductor being disposed between the hose line and said other conductor, in the space therebetween.

14. Apparatus as in claim 10, wherein:

a. the hose line comprises a spiral-wound flexible metal conduit having a helical external metal groove,

b. said one conductor having a heat-insulating jacket and being wound in said external groove.

15. Apparatus as in claim 11, and further including: a. a conductor of low-melting point metal, wrapped around said hose line and connected in a leg of said bridge to in fluence the latter when the low-melting point metal melts and renders the conductor discontinuous.

Claims

1. A combined fire detector and extinguisher hose comprising, in combination: a. a hose line adapted to carry an extinguishing fluid, b. a wire wrap surrounding said hose line, c. said wrap comprising a plurality of electrical conductors insulated from each other, d. one of said conductors having a high and significant temperature coefficient of resistance greater than copper, thereby adapting it for use as a temperature-responsive sensor.

2. A combined fire detector and extinguisher hose comprising, in combination: a. a hose line adapted to carry an extinguishing fluid, b. a wire wrap surrounding said hose line, c. said wrap comprising a plurality of electrical conductors insulated from each other, d. one of said conductors having a high and significant temperature coefficient of resistance greater than copper, thereby adapting it for use as a temperature-responsive sensor, e. a plurality of nozzles connected in said hose line to receive extinguishing fluid therefrom and to discharge the same to the surrounding area, f. said nozzles having orifices sufficiently small to enable a discharging liquid to become frozen in it at temperatures caused by evaporation in a range considerably below ambient.

3. A hose as in claim 2, and further including: a. a separable hose connector fitting carrying one of said nozzles and detachably connecting the same to separate lengths of said hose line, and b. separable eleCtrical connector fittings for detachably connecting the conductors of said lengths at a location adjacent said one hose connector fitting.

4. A combined fire detector and extinguisher hose comprising, in combination: a. a hose line adapted to carry an extinguishing fluid, b. a wire wrap surrounding said hose line, c. said wrap comprising a plurality of electrical conductors insulated from each other, d. one of said conductors having a high and significant temperature coefficient of resistance greater than copper thereby adapting it for use as a temperature-responsive sensor, e. two of the conductors of high temperature coefficient of resistance have different responses to changes in ambient temperature, f. one of said two conductors having heat insulation surrounding it to render it relatively poorly responsive to surrounding heat and g. the other of said two conductors being relatively readily responsive to surrounding heat.

5. A hose as in claim 4, wherein: a. said other conductor of high temperature coefficient of resistance surrounds the said one conductor in spaced relation thereto.

6. A hose as in claim 5, wherein: a. the hose line comprises a spiral-wound flexible metal conduit having a helical external groove, b. said one conductor of high temperature coefficient of resistance having an insulating jacket and being wound in said external groove, c. a spiral wrap of insulation surrounding said metal conduit and one conductor, d. said other conductor of high temperature coefficient of resistance being wound around and external to said spiral wrap.

7. A combined fire detector and extinguisher hose comprising in combination: a. a hose line adapted to carry an extinguishing fluid, b. a wire wrap surrounding said hose line, c. said wrap comprising a plurality of electrical conductors insulated from each other, d. one of said conductors having a high and significant temperature coefficient of resistance greater than copper, thereby adapting it for use as a temperature-responsive sensor, e. the conductors of high temperature coefficient comprise nickel, f. other conductors of said sheath being constituted of low-melting point metal.

8. A hose as in claim 7, wherein: a. two of the conductors of high temperature coefficient of resistance have different responses to changes in ambient temperature, b. one of said two conductors having heat insulation surrounding it to render it relatively poorly responsive to surrounding heat and c. the other of said two conductors being relatively readily responsive to surrounding heat, d. said other conductor of high temperature coefficient of resistance surrounds the said one conductor in spaced relation thereto, e. said low melting point conductors being disposed between said two conductors of high temperature coefficient of resistance.

9. A hose as in claim 8, wherein: a. the hose line comprises a spiral-wound flexible metal conduit having a helical external groove, b. said one conductor of high temperature coefficient of resistance having an insulating jacket and being wound in said external groove, c. a spiral wrap of insulation surrounding said metal conduit and one conductor, d. said other conductor of high temperature coefficient of resistance being wound around and external to said spiral wrap, e. said conductors of low melting point being carried by said spiral wrap of insulation.

10. A hose as in claim 2, and further including: a. a supply of fire-extinguishing fluid connected to one end of said hose line, b. a valve controlling the flow of fluid from said supply to the hose line, c. an electric actuator for said valve, and d. means for delaying the temperature change of one of said two high temperature coefficient conductors when changes in ambient temperature occur, and e. means connected to said high-temperature coefficient conductors, responding to a raPid change in the resistance of only one of said conductors due to a rapid change in ambient temperature surrounding said conductors, for activating said actuator to open the valve whereby extinguishing fluid will be discharged through said hose line.

11. Apparatus as in claim 10, wherein: a. the means responsive to rapid change in the resistance of one of the high-temperature coefficient conductors comprises a bridge circuit connected to said valve actuator and having said conductors in its legs.

12. Apparatus as in claim 10, wherein: a. the means for delaying the temperature change comprises heat insulation surrounding said one high-temperature coefficient conductor.

13. Apparatus as in claim 12, wherein: a. said other conductor is wrapped around the hose line in spaced relation thereto, b. said one conductor being disposed between the hose line and said other conductor, in the space therebetween.

14. Apparatus as in claim 10, wherein: a. the hose line comprises a spiral-wound flexible metal conduit having a helical external metal groove, b. said one conductor having a heat-insulating jacket and being wound in said external groove.

15. Apparatus as in claim 11, and further including: a. a conductor of low-melting point metal, wrapped around said hose line and connected in a leg of said bridge to influence the latter when the low-melting point metal melts and renders the conductor discontinuous.