System for Operating Fire Prevention Devices

This invention relates to systems for operating fire prevention devices, and more particularly to systems for operating a plurality of fire prevention devices such as fire shutters or smoke exhausting openings upon a fire breakout.

It is required to quickly and automatically operate fire shutters or smoke exhausting openings disposed in a building in response to the actuation of fire alarm equipment upon the fire breakout in order to prevent spreading of the fire site and to exhaust the smoke emitted from the fire. However, the conventional system with a plurality of fire prevention devices is arranged to simultaneously energize actuator coils which operate the fire prevention equipment. The actuator coils are connected in parallel through a make contact of a local relay which closes in response to the operation of one of the fire detectors disposed in an appropriate area of the building. Therefore, the system is required to have a large capacity electrical power source and the number and the size of the fire prevention devices, such as fire shutters and smoke exhausting openings, is limited.

Accordingly, the object of the present invention is to provide a system for operating fire prevention devices capable of operating a substantially unlimited number of fire prevention devices with a relatively small capacity electrical power source.

Another object of the invention is to provide a system for operating fire prevention devices operable in quick response to a fire breakout.

Still another object of the invention is to provide a system for operating fire prevention devices reliable in operation.

The invention will now be described in detail in conjunction with the preferred embodiments of the invention illustrated in the accompanying drawings in which:

FIG. 1 is a schematic circuit diagram of the system for operating fire prevention devices constructed in accordance with the present invention; and

FIGS. 2 to 4 are schematic circuit diagrams of modified systems for operating fire prevention devices of the present invention.

Referring now to the drawing and in particular to FIG. 1, the system for operating fire prevention devices of the invention comprises a receiver unit R, a detector unit D and an operator unit OP.

The receiver unit R comprises a suitable d.c. electric source E, with which a local relay N is connected in series through its make contact n.sub.1 and a resistor r. A flicker relay P is also connected in series with the electric source E through a series-connected make contact n.sub.2 of the local relay N and in parallel with the series circuit composed of the local relay N, the make contact n.sub.1 and the resistor r. An indication device, such as a lamp La in this embodiment, is connected in parallel with the electric source E through a pair of parallel-connected make contacts p and m. The contact p intermittently closes when the flicker relay P is energized, and the contact m follows the open-and-close operation of a relay M which is connected to the electric source E through a make contact n.sub.3 of the local relay N and the operator unit OP composed of a plurality of operators OP.sub.1, OP.sub.2, . . . OP.sub.n which will be described in detail later for operating fire prevention devices (not illustrated). The indication lamp La may be replaced by any suitable indicator such as a buzzer, electric bell, etc.

The detector unit D comprises a plurality of fire detectors D.sub.1, D.sub.2 . . . D.sub.n each including a detector element d.sub.1, d.sub.2 . . . or d.sub.n and located at a suitable position in the area to be monitored such as the ceiling of the building. The detectors D.sub.1, D.sub.2 . . . D.sub.n are connected in parallel with one another across the make contact n.sub.1 and the resistor r.

The operator unit OP comprises a plurality of parallel-connected fire prevention device operators OP.sub.1, OP.sub.2 . . . OP.sub.n connected across the electric source E through the make contact n.sub.3 of the relay N. All the operators OP.sub.1, OP.sub.2 . . . OP.sub.n are identical in construction and, therefore, only first operator OP.sub.1 will be described hereinbelow. The first fire prevention device operator OP.sub.1 includes an actuator coil L.sub.1 which, when energized, initiates the operation of the associated fire prevention device such as a shutter or a smoke exhaust opening. Connected in series with the actuator coil L.sub.1 is a limit switch SA.sub.1 which is switched from the first position (shown by a solid line) in which the actuator coil L.sub.1 is energized through the first contact of the coil L.sub.1 to the second position (shown by a broken line) in which the coil L.sub.1 is deenergized and the coil L.sub.2 in the next or second operator OP.sub.2 is energized through the second contact of the coil L.sub.1 when the operation of the fire prevention device is completed. Another switch or contact t.sub.1 is connected in series with the actuator coil L.sub.1, and the contact t.sub.1 is adapted to switch, when a timer T.sub.1 connected in parallel with the actuator coil L.sub.1 is operated, from the first position (shown by a solid line) in which the coil L.sub.1 can be energized through the first contact of the contact t.sub.1 to the second position (shown by a broken line) in which the coil L.sub.1 is deenergized and the actuator coil L.sub.2 in the second operator OP.sub.2 is energized through the second contact of the contact t.sub.1. The operator OP.sub.1 also comprises a limit switch SB.sub.1 which is closed when the fire prevention device associated with the operator OP.sub.1 is completely operated. The limit switches SB.sub.1, SB.sub.2 . . . SB.sub.n are series-connected to the electric source E through the relay M.

When one of the fire detectors D.sub.1 - D.sub.n detects the fire and closes its contact, the local relay N is energized and closes its make contacts n.sub.1 - n.sub.3. Therefore, with the relay N being self-held through the contact n.sub.1, the flicker relay P intermittently operates to repeat the energization and deenergization of the indication lamp La and the timer T.sub.1 and the actuator coil L.sub.1 of the first operator OP.sub.1 are energized through the switches SA.sub.1 and t.sub.1. The actuator coil L.sub.1 then initiates the operation of the fire prevention device by, for example, pulling out a pin which otherwise holds the fire shutter or the closure member of the fire prevention device in the inoperative state, thereby allowing the fire shutter to be closed by any suitable means such as a door closer or allowing the damper of the smoke exhausting port to open by its own weight.

When the fire prevention device associated with the operator OP.sub.1 has completely closed, simultaneously with the closure of the switch SB.sub.1, the limit switch SA.sub.1 switches to the second position as shown by the broken line in FIG. 1. This deenergizes the timer T.sub.1 and the coil L.sub.1 and, at the same time, energizes the timer T.sub.2 and the actuator coil L.sub.2 of the second operator OP.sub.2.

This mode of operation is then successively repeated for each of the second to the nth operators OP.sub.2, OP.sub.3, . . . OP.sub.n until all the operators are operated. After they are all operated, the limit switches SA.sub.1, SA.sub.2, . . . SA.sub.n are all switched to the second position and the limit switches SB.sub.1, SB.sub.2, . . . SB.sub.n are all closed. Then the relay M is operated to close its make contact m to cause the indication lamp La which has been intermittently lit to be continuously energized, indicating that all the fire prevention device such as the shutters or the smoke exhausting ports are operated.

If one or other of the fire prevention devices, for example the device associated to the first operator OP.sub.1, fails to operate for any reason, the limit switch SA.sub.1 disposed in that first operator OP.sub.1 does not switch to the second position. In that event, the timer T.sub.1 actuates its switch contact t from the first position to the second position after the lapse of a predetermined time period. This deenergizes the coil L.sub.1 in that failed operator OP.sub.1 and energizes the timer T.sub.2 and the actuator coil L.sub.2 in the second operator OP.sub.2.

Thus, according to the system for operating fire prevention devices of the present invention, each of the actuator coils L.sub.1, L.sub.2 . . . L.sub.n of the operators OP.sub.1, OP.sub.2 . . . OP.sub.n, such as the fire shutters or the smoke exhausting openings, is operated successively one by one and not simultaneously. Therefore, the electric power source required for operating the fire prevention device can be of smaller capacity than that required for the conventional system, and even with such a smaller power source, the number and the size of the fire prevention devices is not limited. Further, with the system of the present invention, even if one or other of the fire prevention devices fails to operate for any reason, all of the remaining prevention devices in the system can be operated one by one, independently of the fire prevention device in trouble.

Referring to FIG. 2, wherein another embodiment of the present invention is illustrated, the receiver unit R and the operator unit OP of this embodiment are the same as those illustrated in FIG. 1. All of the fire detectors D.sub.1, D.sub.2, . . . D.sub.n are identical in construction and therefore only the first detector D.sub.1 will be described hereinbelow. The detector D.sub.1 includes a detector element d.sub.1 and a control relay A.sub.1 connected in series with the detector element d.sub.1 . A make contact a'.sub.1 of the control relay A.sub.1 is connected across the detector element d.sub.1, while the other make contact a.sub.1 of the control relay A.sub.1 is connected between the electric source E and the limit switch SA.sub.1 in parallel with the make contact n.sub.3 of the local relay N. In other respects, the detectors are the same as those described in conjunction with FIG. 1.

With this circuit arrangement, when one of the fire detectors D.sub.n for instance detects the fire-breakout and closes its contact d.sub.1, the local relay N operates to close the contacts n.sub.1 - n.sub.3. This causes the indication lamp La to begin flickering, the operators OP.sub.1 - OP.sub.n.sub.-1 to successively operate, and causes the control relay A.sub.n of the nth detector D.sub.n to close its contacts a'.sub.n and a.sub.n, thereby self-holding the relay A.sub.n. Then, the operator OP.sub.n of which limit switch SA.sub.n is connected to the contact a.sub.n of the detector D.sub.n operates to actuate the associated fire prevention device simultaneously with the operation of the first operator OP.sub.1 which is carried out in the same way as in the system shown in FIG. 1. In other respects, the system operates similarly to that shown in FIG. 1.

With this circuit arrangement, the fire prevention device located closest to the fire site is first operated simultaneously with the first operator OP.sub.1, providing quick and effective fire prevention.

FIG. 3 illustrates still another embodiment of the present invention, in which the receiver unit R, the fire detector unit D and the operator unit OP themselves are identical to those shown in FIG. 2, only the connection between the respective units being different. That is, the electrical line and the make contact n.sub.3 between the electric source E and the limit switch SA.sub.1 of the first operator OP.sub.1 are omitted from the system shown in FIG. 2, and the normally-open second contact of the limit switch SA.sub.n in the nth operator OP.sub.n is directly connected to the circuit point between the contact a.sub.1 of the detector D.sub.1 and the limit switch SA.sub.1 of the first operator OP.sub.1.

The circuit arrangement of this embodiment operates as follows: When one of the fire detectors, the nth detector D.sub.n for instance, detects the fire breakout and closes its contact d.sub.n, the local relay N actuates to close its contacts n.sub.1 and n.sub.2, thereby causing the indication lamp La to flicker similarly to the previous two embodiments. At the same time, the control relay A.sub.n is also actuated to close its contacts a'.sub.n and a.sub.n, with the control relay A.sub.n being self-held, and the timer T.sub.n and the actuator coil L.sub.n of the operator OP.sub.n are energized to operate the fire prevention device, such as the fire shutter and the smoke exhausting opening, associated with that operator OP.sub.n. After the fire prevention device operated by the operator OP.sub.n has completed its operation, the limit switch SA.sub.n switches from the first position to the second position to deenergize the timer T.sub.n and the actuator coil L.sub.n of the operator OP.sub.n and, at the same time, to energize the timer T.sub.1 and the actuator coil L.sub.1 of the first operator OP.sub.1. This operation of the operator is successively repeated one by one until all of the operators OP.sub.1, OP.sub.2, . . . OP.sub.n complete their operations. After this, the system operates identically to those described in conjunction with FIGS. 1 and 2.

FIG. 4 shows a circuit arrangement of still another embodiment of the present invention, which only differs from the embodiment shown in FIG. 3 in that each of its operators OP.sub.1, OP.sub.2, . . . OP.sub.n includes two diodes b.sub.1 and b.sub.2. The diode b.sub.1 of the second operator OP.sub.2 is connected between the junction between the second contact of the limit switch SA.sub.2 and the second contact of the contact t.sub.2 and the limit switch of the subsequent or third operator. The diode b.sub.2 of the second operator OP.sub.2 is connected between the junction between the second contact of the limit switch SA.sub.2 and the second contact of the contact t.sub.2 and the limit switch of the preceding or first operator OP.sub.1. In other words, the junction between the limit switch SA.sub.2 and the contact t.sub.2 is connected to the preceding and the subsequent operators through the separate diodes b.sub.1 and b.sub.2. Although the operators OP.sub.1 and OP.sub.n also include the diodes b.sub.2 and b.sub.1, respectively, these diodes are not necessarily required for the proper operation of the system alone. These diodes may be left included for easy standardization of the operators, which allows the mass production of the operators as the identical interchangeable components.

With this circuit arrangement, when one of the fire detector D.sub.2 for instance detects a fire breakout and closes its contact d.sub.2, the local relay N is operated to start the flickering of the indication lamp La. At the same time, the control relay A.sub.2 also actuates its contacts a'.sub.2 and a.sub.2 to self-hold the control relay A.sub.2 as well as to energize the timer T.sub.2 and the actuator coil L.sub.2 of the second operator OP.sub.2, thereby actuating the fire prevention device, such as the fire shutter or the smoke exhausting opening, adapted to be operated by that operator OP.sub.2. After this fire prevention device is completely operated, the limit switch SA.sub.2 turns to the second position to deenergize the timer T.sub.2 and the actuator coil L.sub.2 and, simultaneously, energize the timer T.sub.1 and the actuator coil L.sub.1 of the preceeding or first operator OP.sub.1 through the diode b.sub.2 as well as the timer and the actuator coil of the subsequent or third operator through the diode b.sub.1.

Thus, the operation of the fire prevention device starts from the operator associated with the fire detector that first detects the fire breakout and then shifts towards both ends of the system one by one on each side of the first operated operator until all the fire prevention devices involved in the system are completely operated. As in the previous embodiments, the indication lamp La is energized continuously after the operation of all the fire prevention devices, and if any of the fire prevention devices fail to operate completely, the remaining sound devices can successfully be operated due to the function of the timer T and its contact. This embodiment is preferable because it operates the fire prevention device that is the closest to the fire site and can operate the two neighbouring fire prevention devices on both sides of of the first-operated operator at the same time, enabling the system to more quickly and effectively prevent spreading of the fire site.