US3061825A - Fire alarm system and apparatus - Google Patents

Description

Oct. 30, 1962 I E. K- VINING ETA].

FIRE ALARM SYSTEM AND APPARATUS Filed July 6. 1960 AC-Z 2 Sheets-Sheet 1 mum/20 K. w/w/va IE'V/NG E. HARD/N 2 JOSEPH J. 3500/4/74 NO .1.

INVENTORS' Irwin/5Y5 1962 E. K. VlNlNG EIIAI.

FIRE ALARM SYSTEM AND APPARATUS Filed July 6, 1960 2 Sheets-Sheet 2 TROUBI. E

BUZZE 2 AC WEm L2 CRM 2 3854B FIE! i can 1 EDWARD K- V/Nl/VG, lEV/NG E. HARD/IV E JOSEPH \J- Si-CCH/TA/VO JP.

N V EN TORS ,ZZ a a,

United States Patent O 3,061,825 FIRE ALARM SYSTEM AND APPARATUS Edward K. Vining, San Mateo, Irving Edward Hardin,

Castro Valley, and Joseph .1. Secchitano, Jr., Novato,

Caiifi, assignors to Pacific Fire Extinguisher Co., San

Francisco, Calif., a corporation of California Filed July 6, 1960, Ser. No. 41,170 14 Claims. (Cl. 340-227) This invention relates to a fire control system and apparatus.

Fire control systems and apparatus heretofore provided have had several disadvantages. In certain systems, the detector circuit had a low resistance which was often increased by some fault condition to cause a trouble signal to be transmitted. The equipment was often diificult to test and adjust. With some systems it has been impossible to use fixed temperature initiating devices or other open circuit initiating devices with the system. Also, such systems do not provide signals for A.-C. power failure. Also, in certain systems it is necessary to provide local battery on the detector circuit near the manual box. There is, therefore, a need for a new and improved fire alarm system and apparatus.

In general, it is an object of the present invention to provide a new and improved fire alarm system and apparatus which overcomes the above named disadvantages.

Another object of the invention is to provide a fire alarm system and apparatus of the above character in which provision is made for a signal upon local A.-C.

failure.

Another object of the invention is to provide a first alarm system and apparatus of the above character in which provision is made for silencing the trouble buzzer.

Another object of the invention is to provide a fire alarm system and apparatus of 'the'above character in which visual indication is given upon silencing of the fire bell.

Another object of the invention is to provide a control system and apparatus of the abovecharacter in which the battery is located at the central control unit.

Another object of the invention is to provide a fire control system and apparatus of the above character in which visual means indicate the detector circuit involved.

Another object of the invention is to provide a fire alarm system and apparatus of the above character in which other devices can be operated from the system.

Another object of the invention is to provide a fire alarm system and apparatus of the above character in which current and voltage readings can be readily made.

Another object of the invention is to provide a fire alarm system and apparatus of the above character in which the contact relay meter can be readily adjusted and in which the break and fire relays cannot be improperly adjusted.

Another object of the invention is to provide a fire alarm system and apparatus of the above character in which the system can be operated solely on A.-C. or solely from batteries.

Another object of the invention is to provide a fire alarm system and apparatus of the above character in which a separate fire relay is provided for each detector circuit.

Another object of the invention is to provide a fire alarm system and apparatus of the above character which is relatively compact and which can be easily manufactured.

Additional objects and features of the invention will appear from the following description in which the preferred embodiment has been set forth in detail in conjunction with the accompanying drawing.

Referring to the drawing:

FIGURES 1A and 1B show a schematic wiring dia- Patented Oct. 30, 1962 gram of the fire alarm system and apparatus incorporating our invention.

FIGURE 2 is a schematic wiring diagram of a typical detector circuit.

Our fire control system and apparatus, as shown in FIGURE 1, consists of a control unit 8 and a street box 9. The control unit 8 consists of a transformer 10. The primary of the transformer is connected to lines L-1 and L2 which are connected to a suitable source of power such as 115 volts 6O cycle A-C. The Winding of A.-C. relay is connected across the lines L1 and L2 as shown. The secondary of the transformer 10 is connected across the opposite terminals of a bridge rectifier R. The positive terminal of the rectifier is connected to the positive terminal of the battery BA-l and the negative terminal of the rectifier R is connected to the negative terminal of a battery BA-2. The negative terminal of the battery BA-l is connected to the positive terminal of the battery BA-2 through a charge limiting resistor 11. The resistor 11 is provided with an adjustable tap 12 so that the proper charging rate can be selected for the batteries. A pair of contacts AC-1 is connected across the resistor 11.

In this set of contacts and in each set of contacts hereinafter described, the stationary contact is designated by a triangle. When the triangle is solid, this indicates that the contact is made when the relay is tie-energized. If the triangle is not solid or blank, this indicates that the contact is made when the relay is energized. The designations used for the contacts indicate with which relay they are associated. For example, the contacts AC-1 are a part of the relay AC and are operated by the relay AC. A current test jack 13 is provided in series with the negative terminal of the battery BA-1 and the resistor 11. Voltage test jacks 14 and 16 are provided around or in parallel with the batteries BA-l and BA-2 for testing the voltage of the batteries.

The control unit also consists of an output circuit which extends from the positive terminal of the supply battery BA-l over the external conductor 21 to the street box and through the box circuit opener 22, the street box fire line tripping coil T, back to the control unit through external conductor 23 through the normally open break relay contacts B1-1, and the norm-ally open break relay contacts 132-1. The circuit then extends through the external conductor 24, the street box trouble coil U, back to the control unit over external conductor 25, through the Winding of the supervisory relay S, the fire silencing switch PS, the fire bell 26 back to the negative terminal of the battery BA2. Normally, suificient current flows through this supervisory circuit to energize the auxiliarized street box trouble coil U and the supervisory relay coil S.

Another circuit is provided in the control unit which extends from the positive terminal of the battery BA1 through the normally closed trouble signal silencing switch TS, the blank stationary contact and the movable contact of contacts S-1 of the supervisory relay S to two branch circuits 31 and 32. Branch circuit 31 includes a current limiting resistor 33 in series with two serially connected coils B2 and F2 which are the coils for thebreak relay B2 and the fire alarm relay P2. In the same manner, circuit 32 consists of resistor 34 connected serially with the serially connected coils B1 and F1 for the break and fire relays B1 and F1, respectively.

From the arrangement shown, it can be seen. that cir cuits 31 and 32 are parallel circuits. One of these parallel circuits is provided for each of the detector circuits utilized in the fire alarm system. In the circuit shown in FIGURE 1, provision is made for the use of two detector circuits. It is readily apparent, however, that, if desired, other detector circuits may be used merely by providing additional branches in parallel with the branches 31 and 32.

Control means is connected between the battery power supply and each of the branch circuits and is designated as CRMI and CRM2. It consists of suitable devices such as contact relay meters identified as Weston Sensitrol model 705 galvanometer relay. These relay meters, as shown in the drawings, each consist of a winding, stationary break and fire contacts, and a movable needle contact. As shown in the drawing, the break contact of meter CRM1 is connected between the resistor 34 and the break relay coil B1 of the branch, the needle of meter CRM]. is connected between the break relay coil B1 and the fire relay coil F2 and the fire contact of meter CRMl is connected to the positive terminal of the battery BA2. The meter CRM2 is connected in a similar manner to branch 31.

-In FIGURE 2 we have shown a typical detector circuit which consists of a battery 41 which is connected to resistors 42, .43 and 44. Resistor 42 is provided with a tap 46 so that a predetermined voltage drop can be created across the resistor 44. The voltage drop across the resistor 44 causes supervisory current to flow through a supervisory loop consisting of the coil of the contact relay meter CRMl and the detector loop 46 which includes an end line resistor 47. Manual boxes such as that indicated at 48 or other normally open circuit initiating devices can be placed across the end line resistor 47 as Shown.

Detectors 49 of a suitable type such as the fire detector heads manufactured by Baso, Inc. of Milwaukee, Wisconsin, identified by type No. TlOOAl are placed in series in the detector loop 46. V

The current flowing in this supervisory loop in the detector circuit is sufiicient to maintain the needle of the contact relay meter in a mid-point or center position between the break and fire contacts as shown in FIGURE 1.

Only one detector circuit is shown; the other detector circuits are substantially identical and would operate in the same way to control the associated contact relay meter. 7

When one of the detecting heads connected in the detecting loop is heated because of a fire in the vicinity of the detecting head, the detecting head works on the thermopile principle and adds to the supervisory current and causes the needle of the relay meter CRMl to engage the fire contact. The contact is magnetically locked in this position by the meter. Operation in much the same way is obtained when a manual box 48 is closed across the resistor 47. Supervisory current is again caused to increase to cause the meter CRMl to establish contact between its needle and the fire contact.

When the contact relay meter CRMll is locked in the fire alarm position, the fire alarm relay F1 is connected directly across the supply battery 3A2 to cause operation of the fire alarm relay. Contacts F11 close to place the voltage of both batteries BA1 and BA2 across the street box fire coil T. Energization of this coil mechanically operates the circuit opener 22 to remove current from the street box circuit. Energization of the street box fire coil also serves to trip the fire alarm coding mechanism (not shown) of the street box to cause the transmission of a coded fire alarm signal to the fire department.

Operation of the fire relay F1 causes closing of its contacts F12 to sound the fire bell 26 through the contacts S2 of the supervisory relay. The contacts S2 are closed because the supervisory relay has been de-energized by opening of the circuit opener 22. De-energization of the supervisory relay causes the movable contact of contacts S1 to shift from the blank stationary contact to the solid stationary contact. This causes de-energization of the break relays to remove their current drain from the power supply and the energization of the trouble buzzer 56. This buzzer can be silenced by opening trouble switch TS.

Contacts F13- are also operated by energization of the relay F1 and cause energization of the pilot light L1 to indicate that a fire condition is present in the locality of the detector circuit No. 1. Thus, even though the 5 trouble buzzer is operating, the fire bell and the fire light readily indicate that it is a fire that is causing the trouble. Additional types of alarms such as an external annunciator 51 shown may be connected to the contacts F1-3. The closing of the contacts F1-3 can also be utilized for other functions such as closing doors, shutting oif fans, and so forth. Contacts F1-4 are also operated by the energization of the tire relay F1 and serve to provide a supplemental power supply for the fire alarm bell 26 through the resistor 52 in the event of failure of the power supply BA-Z.

After the hereinbefore described fire alarm operation has taken place, the local fire alarm bell 26 can be silenced by opening the fire silencing switch PS. The pilot light L1, however, will remain lit.

After the device which caused the fire alarm signal to be created has been returned to normal, the contact relay meter CRMI is reset manually by releasing the magnetic lock on the needle and returning the pointer or needle to its normal mid-point position. The magnetic lock is utilized so that if only a momentary fire signal occurs, trouble shooting can be done to see why the momentary fire alarm condition occurred.

Before the system can be restored to normal, the circuit opener 22 must be manually closed. Reset push button PB is then operated to cause energization of the supervisory relay S. Energization of the relay S causes its contacts 8-1 to move to the position shown in FIG- URE 1 to cause energization of the break relays B1 and B2 and closing of the contacts B11 and B21. As hereinbefore explained, the break relays B1 and B2 were deenergized at the time the supervisory relay S was deenergized.

Upon opening of the fire contacts of relay CRMl, the associated fire relay F1 is de-energized to cause opening of its contacts F1-1, F1-2, F13 and F1-4.

It will be noted thatthe reset push button has been placed in the street box or the remotely located auxiliary unit. It is felt that this is very desirable because the fire system alarm owner or user cannot leave the system in other than a normal condition. The repairman or fire inspector must close the circuit opener 22 to place the street box fire coil in the circuit before the system can be re turned to normal.

A single open circuit fault condition in any of the detector circuits connected to the control unit will cause tie-energization of the associated contact relay meter. Upon occurrence of such a condition, the needle of the contact relay meter falls to the break position and closes the break contact. The contacts are magnetically locked in this position to shunt the coil of the break relay to permit the contacts of relay B to move to an open position. The associated contacts such as Bl-l is opened to open the circuit to the supervisory relay S and to deenergize the same as Well as the street box coil U. Deenergization of the trouble coil causes the transmission of a coded trouble signal to the fire department through a mechanism (not shown). Contacts S1 move to a position to remove the battery potential from the break relays and to close the circuit to energize the trouble buzzer 56 through the trouble silencing switch TS. Switch S3 is closed to light a trouble pilot light L3. The trouble buzzer 56 can be silenced by opening the trouble switch TS. When the system is in this condition, all of the break and fire relays are de-energized because of the operation of the contacts S1. Thus, all drain from the trouble supply battery is eliminated except for the trouble pilot light.

After the trouble condition has been repaired, the system can be restored to normal in a manner very similar to that hereinbefore described. The contact relay meter is reset manually from the magnetically locked trouble position. The trouble silencing switch is then closed to start the trouble buzzer 56 operating. The street box fire coil is energized by closing the reset push button PB. At the same time the coil of supervisory relay S is energized to cause the contacts S1 to return to the normal position to apply power to the break and fire relays. This causes contacts B11 and B2-1 to be closed to establish a circuit to maintain energization of the street box fire coil, the street box trouble coil U and the supervisory relay S. The reset push button may then be released. The movement of the contact S4. to its normal position opens the circuit to the trouble buzzer. As soon as the contacts B14 and 132-1 are closed and the reset push button is released, the street box trouble coil is placed in the circuit and energized.

If a single open circuit fault occurs in a circuit running through the street box, the trouble relay coil U in the street box is de-energized which causes the operation of a mechanism (not shown) to transmit a coded trouble signal to the fire department. The supervisory relay S is also de-energized producing the trouble signal as described in connection with a fault in the detector circuit. The fault condition is repaired, the trouble signal silencing switch is restored and the system is reset as hereinbefore described.

After a fire alarm signal has been received from the fire bell 26, it may be silenced by operating the fire silencing switch PS. The normal supervisory current in the circuit is insufiicient to operate the fire bell 26. When the circuit opener in the street box is operated because of a fire alarm signal, the trouble signal is also initiated. This trouble signal may also be silenced by operating the trouble silencing switch TS. Both of the silencing switches and the circuit opener on the street box must be restored before the system can be reset to a normal supervisory position. For that reason, if either of the silencing switches is operated while the system is in the normal supervisory position, a trouble signal will be transmitted to the fire department and sounded on the local trouble buzzer 56. The system must then be reset before the system can be returned to its normal supervisory position.

In the event of a power failure to the battery charge circuit, a separate trouble signal and trouble pilot light L4 are energized by operation of the supervisory relay AC. The supervisory relay AC upon power failure is de-energized causing its contacts AC-l to be operated to remove resistor 11 from the battery circuit. Contacts AC-Z are operated to move the movable contact position from the blank stationary contact to the solid stationary contact to energize the light L4 and the A.C. buzzer 61 through an A.C. silencing switch 62. The buzzer 61 may be silenced by opening the switch 62. This trouble signal is not transmitted to the fire department and the circuits do not need to be reset on restoration.

When the system is in normal supervisory position, operation of the local fire alarm signal silencing switch PS opens the supervisory circuit resulting in a trouble signal to the fire department and a local trouble signal until the fire silencing switch is closed and the system restored in a manner similar to that hereinbefore described.

By way of example, one embodiment of our invention had the following values for certain of its components:

In this embodiment, it was found that approximately 2.6 m'r li-amperes D.-C. flow in each of the branch circuits 32 and 33 and through the break and fire coils. A current of approximately 60 milli-amperes flowed through the circuits to the street box and through the supervisory relay S. A supervisory current of approximately 2 milliamperes flowed through the circuit comprised of resistors 42, 43 and 44 in FIGURE 2. Under normal conditions, a current of approximately 34 micro-amperes flowed through the detector loop 47. With the conventional type of thermopiles hereinbefore described, operating on a rate of rise principle, it was found that an output of approximately 4 micro-amperes from the thermopile was sufiicient to cause the contact relay meter to move to a fire position.

It is apparent from the foregoing that we have developed a new and improved fire alarm system and apparatus which contains many safety features so that the system cannot be left by a repairman or fireman without placing the system in its normal operating condition.

The system is arranged in such a manner that if a fire occurs in a circuit after a trouble condition has been etected on a diiferent circuit, the system can still transmit a fire signal. The trouble signal is operated from the battery BA-l, whereas the subsequent operation for a fire condition is powered from battery BA-2. The system can operate completely from A.C. if the batteries are disconnected from the system. 1 Likewise, the system can operate solely from the batteries if the A.C. is disconnected from the system. The voltage and the current test jacks make it possible to test the circuits without interrupting the normal operation of the fire alarm system.

We claim:

1. In a fire alarm system, a control unit, a remotely located auxiliary unit, electrical circuit means connecting the auxiliary unit to the control unit, at least one detector circuit, electrical circuit means connecting the detector circuit to the control unit, a 11-0. power supply at the control unit, a branch circuit at the control unit for each detecting unit, each branch circuit including a break relay and a fire relay, each of the break and fire relays having a coil and a set of contacts, the coil of the break relay and the coil of the fire relay of each branch circuit being connected in series, a supervisory relay at the control unit having a coil and a set of contacts, means for establishing a circuit from the power supply through the set of contacts of the supervisory relay and through the branch circuit to provide supervisory current flow through the branch circuit, the supervisory current flow being sufficient to operate the break relay but being insutficient to operate the fire relay, control means connected between each of the branch circuits and the power supply, the control means including a coil and contact means movable between break and fire positions, the contact means in a break position serving to shunt the break coil to cause the break relay to drop out and in a fire position serving to place the fire coil across the power supply to cause the fire relay to operate, each detecting circuit including a plurality of heat detecting devices connected into a loop, said coil of the contact means being connected in series in said loop, means for impressing a current flow in the loop, a circuit opener, a fire coil and a trouble coil at the auxiliary unit, the contact means of the break relays being connected in series with the fire coil and the trouble coil, means for connecting the electrical circuit means connecting the 4. A fire alarm system as in claim 1 wherein said means controlled by the fire relay contacts for initiating an alarm includes a fire bell, and a fire signal ight.

5. A fire alarm system as in claim 1 together with means controlled by the break relay contacts for initiating an alarm.

6. A fire alarm system as in claim 1 wherein said DC. power supply includes a pair of batteries, and wherein said break relays when energized are connected to one of said batteries and wherein said fire relays when energized are connected to the other of said batteries.

7. In a fire control system, a control unit, a remotely controlled auxiliary unit, electrical circuit means connecting the auxiliary unit totthe control unit, at least one detector circuit, electrical circuitmeans connecting the detector circuits to the control unit, an A.-C. power supply, first and second batteries, means for rectifying the A.-C. from the power supply to apply charging current to the first and second batteries to maintain the batteries continuously charged, a branch circuit at the control unit for each detecting circuit utilized, each branch circuit including a break relay, a fire relay and a resistor, the

resistor and the coils of the break relay and the fire relay being connected in series, a supervisory relay at the control unit having a coil and two sets of contacts, circuit means for establishing a circuit from the first battery through one of the sets of contacts of the supervisory relay to the branch circuits to provide supervisory current flow through the branch circuits, the supervisory current flow being suificient to operate the break relay but being insutficient to operate the fire relay, control means connected between each of the branch circuits and one of the power supplies, the control means including a coil and contact means movable between break and fire positions, the contact means in the break position serving to shunt the break coil to cause the break relay to drop out and in the fire position serving to place the fire coil across the second battery to cause the fire relay to operate, each detecting circuit including a plurality of heat de- 8 tecting devices connectedi-nto a loop, said coil of the control means being connectedin series in the loop, means for impressing a current flow in the loop, said heat detecting devices being capable of'increasing the current flow in the loop upon detection of heat, a circuit opener, a fire coil and a trouble coil at the auxiliary unit, the contact means of the break relays being connected in series with the fire coil and the trouble coil at the auxiliary unit, the coil of the supervisory relay being connected inseries with the trouble and fire coils, and means energized by the fire relay for placing the fire coil directly across both of said batteries on operation or the fire relay to cause the fire coil to operate the circuit opener.

8. A fire alarm system as in claim 7 together with a trouble buzzer, means including a trouble silencing switch for connecting the trouble buzzer across said first battery, said set of contacts of said supervisory relay upon dcenergization of the supervisory relay serving to disconnect the branch circuits from said first battery and connecting said first battery to said trouble buzzer.

9. A fire alarm system as in claim 7 wherein said supervisory relay includes an additional set of contacts, and fire alarm means operated by said additional set of contacts to. A fire alarm system as in claim 9 wherein each of said fire relays includes an additional contact means, alarm lights operated by said additional contact means, and external annunciator means operated by said additional contact means.

11. A fire alarm system as in claim 10 together with an A.-C. relay having a coil and contact means, the coil being connected across the A.-C. power supply, and means actuated by said contact means upon de-energization of said A.-C. relay.

12.'A fire alarm system as in claim 9 wherein said fire relay is provided with additional contact means for supplying power to said fire alarm means.

13. A fire alarm system as in claim 11 together with reset means for bypassing the trouble coil to energize the supervisory relay.

14. A fire alarm system as in claim 7 together with means permitting a rapid check on the charging current flow to said batteries and the voltage of each of said batteries.

References Cited in the file of this patent UNITED STATES PATENTS 2,452,942 Lord Nov. 2, 1948

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