CA1050135A - Fire protection system - Google Patents
Fire protection systemInfo
- Publication number
- CA1050135A CA1050135A CA234,100A CA234100A CA1050135A CA 1050135 A CA1050135 A CA 1050135A CA 234100 A CA234100 A CA 234100A CA 1050135 A CA1050135 A CA 1050135A
- Authority
- CA
- Canada
- Prior art keywords
- activators
- current flow
- actuator
- suppressor units
- initiation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62C—FIRE-FIGHTING
- A62C37/00—Control of fire-fighting equipment
Landscapes
- Health & Medical Sciences (AREA)
- Public Health (AREA)
- Business, Economics & Management (AREA)
- Emergency Management (AREA)
- Fire-Extinguishing By Fire Departments, And Fire-Extinguishing Equipment And Control Thereof (AREA)
Abstract
APPLICATION FOR CANADIAN LETTERS PATENT
Robert F. Davis Carl I. Swanson TITLE
FIRE PROTECTION SYSTEM
ABSTRACT OF THE DISCLOSURE
Disclosed is a fire protection system including a plurality of suppressor units activatable to suppress a detected fire; a plurality of electrical current responsive activators, one associated with each of said suppressor units and adapted to induce activation thereof; a control circuit connecting the activators in series and including an actuator for initiating activating current flow to the activators; and an auxiliary circuit comprising switch means for connecting the activators in parallel in response to the initiation of activating current flow by the actuator.
Robert F. Davis Carl I. Swanson TITLE
FIRE PROTECTION SYSTEM
ABSTRACT OF THE DISCLOSURE
Disclosed is a fire protection system including a plurality of suppressor units activatable to suppress a detected fire; a plurality of electrical current responsive activators, one associated with each of said suppressor units and adapted to induce activation thereof; a control circuit connecting the activators in series and including an actuator for initiating activating current flow to the activators; and an auxiliary circuit comprising switch means for connecting the activators in parallel in response to the initiation of activating current flow by the actuator.
Description
~050135 BACKGROUND OF THE INVENTION
This invention relates generally to fire protection systems and, more particularly, to fire protection systems in which a plurality of individual fire suppressor units are simultaneously activated to extinguish a fire.
Certain fire protection systems employ a plurality of strategically located suppressor units, each including an ex-tinguishant filled vessel and an electrically operated release mechanism for inducing discharge of the extinguishant in response to detection of a fire. When simultaneous operation of all suppressor units is desired, the system is provided typically with a control circuit that produces coincident activation of all release mechanisms. In such systems, it is common technique to electri-cally supervise the electric integrity of the release mechanisms by providing and monitoring a trickle current through a series connection thereof. Although this series supervision establishes a constant knowledge of release mechanism ihtegrity, there remains the possibility that a single release member failure will cause ~ failure of the entire serles system. In addition, even a detected failure of a release mechanism can prevent system opera-tion if the detected failure occurs coincidentally with a demand for system actuation.
The object of this invention, therefore, is to provide a more reliable fire protection system of the type employing a plur-ality of individual suppressant units all having electrically operated release mechanisms adapted for coincident activation.
SUMMARY OF THE INVENTION
The present invention provides a fire protection system including a plurality of suppressor units activatable to s~ppress a detected fire; a plurality of electrical current responsive acti-vators, one associated with each of said suppressor units and adapt-ed to induce activation thereof; a control circuit connecting the - 1 , - ~
.
1050~3S
activators in series and including an actuator for initiating acti-vating current flow to the activators; and an auxiliary circuit com-prising switch means for connecting the activators in parallel in response to the initiation of activating current ~low by the actuator.
Because of the switching provided by the auxiliary circuit, all func-tional activators will operate even in the event that a single ac-tivator fails in such a way as to prevent normal series operation of the system.
In a preferred embodiment of the invention, the individual suppressor units comprise vessels filled with a fire suppressing agent that is released by activation of an explosive squib. The actuator is a device that initiates current flow to the series con-nected activator squibs and can be either a manually operated switch or a condition responsive device such as a thermal switch, or a products-of-combustion detector.
Another feature of the invention is the provision of a delay for the auxiliary circuit that ensures normal series opera-tion of the individual activators in the absence of any individual failure thereof that would prohibit such operation.
DESCRIPTION OF THE DRAWING
-These and other objects and eatures of the present in-vention will become more apparent upon a perusal of the following description taken in conjunction with the accompanying drawing, which is a schematic circuit diagram illustrating a preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, there are shown a plurality of vessels filled with a suitable fire extinguishing agent and dis-tributed strategically throughout a fire protected zone. Each of the vessels 11 is provided with an explosive squib 12 that is ~050135 detonated by electrical current flow to induce release of the agent contained in the associated vessel 11. The vessels 11 and activators 12 are conventional and of a type, for example, disclosed in United States Patents Nos. 2,693,240 and 3,523,583. Connecting the acti-vators 12 in series with a power source 13 is a control circuit that includes an actuator switch 14. Although the actuator 14 can be a simple manual switch, it preferably comprises a condition res-ponsive sensor that closes the circuit between the power source 13 and the activators 12 in response to detection of a given abnormal condition such as fire. Suitable condition responsive sensors in-clude, for example, thermal switches such as disclosed in United States Patents Nos. 2,537,028 and 3,423,585. ~onnected in series between activators 12 an~ the power source 13 is a supervisory net-work including a relay coil 16 that provides a limited supervisory current flow through the activators 12. Operated by the coil 16 are normally-closed contacts 17 connecting a power supply 18 and an indicator light 19.
An auxiliary control circuit 21 includes a plurality of normally open contacts Kl and K2 that, when closed, connect the activators 12 in parallel: across the power source 13. Controlling the contacts Kl and K2 is a relay coll K connected in series with a delay circuit 22 across the actuator 12 and the power source 13.
During normal operation, a suprevisory current of, for example, 5 - 10 milliamps flows through the activators 12 and the relay 16 maintaining the contacts 17 open and the indicator light 19 de-energized. However, any failure such as an individual acti-vator with an abnormally high resistance that would prevent activat-ing current flow through the series-connected activators 12 also will reduce supervisory current flow to less than the hold-in level for the winding 16, allowing the contacts 17 to close and thereby energize the indicator lamp 19. Having observed the energized light 1050~35 19, maintenance personnel can examine the control circuit and correct the fault to regain system inte~rity.
In response to an abnormal environmental condition such as fire, the closing of the switch, either manually or by a suitable sensor, will initiate activating current flow and thus coincidentally activate all of the activator devices 12. Also, when the switch 1~
is closed, the Delay 22 is activated. Upon expiration of the speci-fied delay, the relay coil K will activate, resulting in the closing of the relay contacts Kl and K2. These contact closures transfer the activators 12 from their initial series connection into a par-allel connection with the result that they are now independentlyplaced in parallel across the power source 13. If there were a partial or total system failure during the initial series initia-tion due to an open or high resistance activator, then all but the affected activator would be activated with the transfer to parallel mode. Thus, a series activator failure will result in no more than a single failure rather than potentially a total system failure.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings.
For example, it will be obvious that the invention can be used with systems having more than three suppressor units by merely increasing the number of switches in the auxiliary circuit 21. It is therefore to be understood that within the scope of the appended claims the invention can be practised otherwise than as specifically described.
This invention relates generally to fire protection systems and, more particularly, to fire protection systems in which a plurality of individual fire suppressor units are simultaneously activated to extinguish a fire.
Certain fire protection systems employ a plurality of strategically located suppressor units, each including an ex-tinguishant filled vessel and an electrically operated release mechanism for inducing discharge of the extinguishant in response to detection of a fire. When simultaneous operation of all suppressor units is desired, the system is provided typically with a control circuit that produces coincident activation of all release mechanisms. In such systems, it is common technique to electri-cally supervise the electric integrity of the release mechanisms by providing and monitoring a trickle current through a series connection thereof. Although this series supervision establishes a constant knowledge of release mechanism ihtegrity, there remains the possibility that a single release member failure will cause ~ failure of the entire serles system. In addition, even a detected failure of a release mechanism can prevent system opera-tion if the detected failure occurs coincidentally with a demand for system actuation.
The object of this invention, therefore, is to provide a more reliable fire protection system of the type employing a plur-ality of individual suppressant units all having electrically operated release mechanisms adapted for coincident activation.
SUMMARY OF THE INVENTION
The present invention provides a fire protection system including a plurality of suppressor units activatable to s~ppress a detected fire; a plurality of electrical current responsive acti-vators, one associated with each of said suppressor units and adapt-ed to induce activation thereof; a control circuit connecting the - 1 , - ~
.
1050~3S
activators in series and including an actuator for initiating acti-vating current flow to the activators; and an auxiliary circuit com-prising switch means for connecting the activators in parallel in response to the initiation of activating current ~low by the actuator.
Because of the switching provided by the auxiliary circuit, all func-tional activators will operate even in the event that a single ac-tivator fails in such a way as to prevent normal series operation of the system.
In a preferred embodiment of the invention, the individual suppressor units comprise vessels filled with a fire suppressing agent that is released by activation of an explosive squib. The actuator is a device that initiates current flow to the series con-nected activator squibs and can be either a manually operated switch or a condition responsive device such as a thermal switch, or a products-of-combustion detector.
Another feature of the invention is the provision of a delay for the auxiliary circuit that ensures normal series opera-tion of the individual activators in the absence of any individual failure thereof that would prohibit such operation.
DESCRIPTION OF THE DRAWING
-These and other objects and eatures of the present in-vention will become more apparent upon a perusal of the following description taken in conjunction with the accompanying drawing, which is a schematic circuit diagram illustrating a preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, there are shown a plurality of vessels filled with a suitable fire extinguishing agent and dis-tributed strategically throughout a fire protected zone. Each of the vessels 11 is provided with an explosive squib 12 that is ~050135 detonated by electrical current flow to induce release of the agent contained in the associated vessel 11. The vessels 11 and activators 12 are conventional and of a type, for example, disclosed in United States Patents Nos. 2,693,240 and 3,523,583. Connecting the acti-vators 12 in series with a power source 13 is a control circuit that includes an actuator switch 14. Although the actuator 14 can be a simple manual switch, it preferably comprises a condition res-ponsive sensor that closes the circuit between the power source 13 and the activators 12 in response to detection of a given abnormal condition such as fire. Suitable condition responsive sensors in-clude, for example, thermal switches such as disclosed in United States Patents Nos. 2,537,028 and 3,423,585. ~onnected in series between activators 12 an~ the power source 13 is a supervisory net-work including a relay coil 16 that provides a limited supervisory current flow through the activators 12. Operated by the coil 16 are normally-closed contacts 17 connecting a power supply 18 and an indicator light 19.
An auxiliary control circuit 21 includes a plurality of normally open contacts Kl and K2 that, when closed, connect the activators 12 in parallel: across the power source 13. Controlling the contacts Kl and K2 is a relay coll K connected in series with a delay circuit 22 across the actuator 12 and the power source 13.
During normal operation, a suprevisory current of, for example, 5 - 10 milliamps flows through the activators 12 and the relay 16 maintaining the contacts 17 open and the indicator light 19 de-energized. However, any failure such as an individual acti-vator with an abnormally high resistance that would prevent activat-ing current flow through the series-connected activators 12 also will reduce supervisory current flow to less than the hold-in level for the winding 16, allowing the contacts 17 to close and thereby energize the indicator lamp 19. Having observed the energized light 1050~35 19, maintenance personnel can examine the control circuit and correct the fault to regain system inte~rity.
In response to an abnormal environmental condition such as fire, the closing of the switch, either manually or by a suitable sensor, will initiate activating current flow and thus coincidentally activate all of the activator devices 12. Also, when the switch 1~
is closed, the Delay 22 is activated. Upon expiration of the speci-fied delay, the relay coil K will activate, resulting in the closing of the relay contacts Kl and K2. These contact closures transfer the activators 12 from their initial series connection into a par-allel connection with the result that they are now independentlyplaced in parallel across the power source 13. If there were a partial or total system failure during the initial series initia-tion due to an open or high resistance activator, then all but the affected activator would be activated with the transfer to parallel mode. Thus, a series activator failure will result in no more than a single failure rather than potentially a total system failure.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings.
For example, it will be obvious that the invention can be used with systems having more than three suppressor units by merely increasing the number of switches in the auxiliary circuit 21. It is therefore to be understood that within the scope of the appended claims the invention can be practised otherwise than as specifically described.
Claims (12)
1. An electrical protection system comprising;
a plurality of suppressor units activatable to suppress an abnormal condition;
a plurality of electrical current responsive activators, one associated with each of said suppressor units and adapted to induce activation thereof;
electrical current supply means;
control circuit means connecting said activators in series and comprising actuator means for initiating activating current flow from said supply means to said series connected activators; and auxiliary circuit means comprising switch means for connecting said activators in parallel in response to initiation of activating current flow by said actuator means.
a plurality of suppressor units activatable to suppress an abnormal condition;
a plurality of electrical current responsive activators, one associated with each of said suppressor units and adapted to induce activation thereof;
electrical current supply means;
control circuit means connecting said activators in series and comprising actuator means for initiating activating current flow from said supply means to said series connected activators; and auxiliary circuit means comprising switch means for connecting said activators in parallel in response to initiation of activating current flow by said actuator means.
2. A system according to claim 1 wherein said auxiliary cir-cuit means comprises delay means for delaying connection of said activators in parallel after initiation of activating current flow by said actuator means.
3. A system according to claim 2 wherein said suppressor units comprise vessels containing a fire suppressing agent.
4. A system according to claim 3 wherein said activators com-prise explosive squibs for inducing release of said suppressing agent from said vessels.
5. A system according to claim L wherein said actuator means comprises a sensor means for detecting said abnormal condition.
6. A system according to claim 5 wherein said auxiliary cir-cuit means comprises delay means for delaying connection of said activators in parallel after initiation of activating current flow by said actuator means.
7. A system according to claim 6 wherein said suppressor units comprise vessels containing a fire suppressing agent.
8. A system according to claim 7 wherein said sensor means comprises a thermal detection means.
9. A system according to claim 1 including supervision circuit means for supplying a supervisory current flow through said series connected activators, said supervisory current flow being insuffi-cient to activate said activators, and wherein said supervision circuit means comprises indicator means for monitoring said supervisory current flow.
10. A system according to claim 9 wherein said auxiliary cir-cuit means comprises delay means for delaying connection of said activators in parallel after initiation of activating current flow by said actuator means.
11. A system according to claim 10 wherein said suppressor units comprise vessels containing a fire suppressing agent.
12. A system according to claim 11 wherein said actuator means comprises a sensor means for detecting said abnormal condition.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US500864A US3917001A (en) | 1974-08-27 | 1974-08-27 | Fire protection system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1050135A true CA1050135A (en) | 1979-03-06 |
Family
ID=23991257
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA234,100A Expired CA1050135A (en) | 1974-08-27 | 1975-08-19 | Fire protection system |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US3917001A (en) |
| CA (1) | CA1050135A (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4013128A (en) * | 1976-04-19 | 1977-03-22 | Walter Kidde & Company, Inc. | Modular fire protection system |
| US4185277A (en) * | 1978-02-16 | 1980-01-22 | Corso Philip P | Trip alarm circuit |
| US4199029A (en) * | 1978-04-10 | 1980-04-22 | Fike Metal Products Corporation | Multiple, independently actuatable fire suppression devices each having individual actuating power source |
| SE423317B (en) * | 1979-06-13 | 1982-05-03 | Bofors Ab | SET AND DEVICE FOR DISPLACING THE SPRINKLER MENZES |
| US4643260A (en) * | 1985-09-26 | 1987-02-17 | The Boeing Company | Fire suppression system with controlled secondary extinguishant discharge |
| US4905765A (en) * | 1988-08-22 | 1990-03-06 | Hein George P | Smoke detector/remote controlled shape-memory alloy fire extinguisher discharge apparatus |
| US5532675A (en) * | 1994-12-29 | 1996-07-02 | Linda Johnson | Alarm tester |
| DE19638626C2 (en) * | 1996-09-20 | 1998-12-24 | Amtech R Int Inc | Fire extinguishing system |
| US6059046A (en) * | 1998-03-05 | 2000-05-09 | Grunau Company, Inc. | Low pressure carbon dioxide fire protection system for semiconductor fabrication facility |
| DE10361020B4 (en) * | 2003-12-24 | 2010-09-30 | Airbus Deutschland Gmbh | Fire fighting equipment |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2373819A (en) * | 1943-11-24 | 1945-04-17 | Clarence B Eaton | Fire extinguisher |
| US2814795A (en) * | 1954-09-24 | 1957-11-26 | Robert J Spooner | Alarm systems |
-
1974
- 1974-08-27 US US500864A patent/US3917001A/en not_active Expired - Lifetime
-
1975
- 1975-08-19 CA CA234,100A patent/CA1050135A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US3917001A (en) | 1975-11-04 |
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