Communications: electrical – Condition responsive indicating system – With particular coupling link
Reexamination Certificate
2002-03-27
2004-04-27
Crosland, Donnie L. (Department: 2632)
Communications: electrical
Condition responsive indicating system
With particular coupling link
C340S533000, C340S537000, C340S539100, C340S286050, C340S286080, C340S287000, C340S291000, C340S299000, C340S307000, C340S315000
Reexamination Certificate
active
06727815
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not Applicable.
BACKGROUND OF THE INVENTION
Fire alarm systems usually have a multiplicity of individual alarm boxes which are arranged at various locations of a building or block of buildings requiring protection and are connected to a control centre. As a rule, alarm boxes are connected to the control centre via a loop feeder or dead-end feeder where the so-called communication mode, i.e. the way signals are transmitted from the alarm boxes to the control centre and vice versa, may be based on a direct-current technique or digital signal technique. In the latter case, the communication pathway is a data bus via which digital data words are transmitted from the alarm boxes to the control centre and vice versa. The digital communication technique naturally has the advantage that a great variety of individual digital words can be transmitted. Thus, in the case of an alarm signal, not only is the signal transmitted, but also the address of the alarm box. In addition, an trouble signal may be transmitted. Conversely, the control centre may communicate with the individual alarm boxes.
The alarm boxes of such systems are push-button operated alarm boxes in the simplest case or are sensor-bound elements, possibly with an “intelligence” of their own.
As is explained in EP 0 803 850 A1 a wire-bound communication between the control centre and the individual alarm boxes does ensure high safety in communication, but makes the system relatively inflexible to changes in a room distribution once made or the function and/or occupation of rooms. Such changes normally result in the fact that individual alarm boxes need to change their location, which involves extensive and annoying installation work because of the wiring which then will be required. Even a subsequent extension of fire alarm systems by wirings between the communication pathway normally designed as a cable and the alarm boxes possibly proves to involve great expenditure. Therefore, it has been known from the aforementioned document to connect the alarm boxes to the wires of the communication pathway selectively via a wire-bound channel or a wireless channel, e.g. by means of a radio network system in the latter case. The communication pathway has coupled thereto a relay means which has a receiver for the wireless transmitting alarm boxes.
From DE 42 19 555 A1, it has been known, in conjunction with an installation facility of the building system control equipment, to connect subscriber stations and control devices to a serial bus system. It has further been known here to feed data to the bus system even without using any wires, e.g. by means of an infrared transmitter and an infrared receiver associated therewith. Wireless transmission may also be performed via other media such as a radio network or ultrasonic sound. As a rule, one receiver is triggered by several transmitters which can be in a stationary or mobile arrangement. The onboard network of the individual transmitters, as a rule, is fed from a battery which has a major or minor service life depending on the frequency at which they are actuated.
From EP 0 803 850 A1 which was mentioned earlier, it has also become known to provide two sets of alarm boxes of which one is wire-bound and the other one is connected to the communication pathway via a radio network. The individual alarm boxes equipped for radio network communication are supplied with power from a battery. The relay means has a microprocessor which converts signals received from the alarm boxes into appropriate digital signals.
It is understood that the design of the relay means is such as to provide compatibility with the communication mode on the bus. Various different communication buses have become known, even for fire alarm systems already.
Older fire alarm systems which still have been ready for operation up to now employ direct-current transmissions adopting the current-increasing or current-decreasing principle.
It is the object of the invention to provide a fire alarm system or a possibility of extending fire alarm systems that exist already wherein additional alarm boxes may be coupled to conventional wire-bound fire alarm systems in a simple manner which requires little expenditure.
BRIED SUMMARY OF THE INVENTION
According to the invention, a set of different coupling modules is provided which may selectively be disconnectably disposed in the relay means and are adapted to be connected to the signal evaluation circuit and the wire-bound communication pathway via appropriate connecting elements. The coupling modules are matched to the communication mode of the communication pathway. For example, if digital signals are transmitted the coupling module communicates with the control centre via digital signals which are adapted to be “understood” by the control centre. In contrast, if the communication pathway uses direct-current transmission the coupling module arranges for signal transmission to the control centre to be performed via a current decrease or increase according to the known technique.
Therefore, according to the inventive fire alarm system, a unitary relay means may be provided which has a receiver for the wireless reception of signals from the alarm boxes, a power supply unit, and a signal evaluation circuit. It is merely the coupling module which needs to be selected with regard to the communication mode and to be inserted into the relay means. In this way, an existing fire alarm system may be modified or supplemented by simple means with no regard to which communication mode exists on the communication pathway.
An aspect of the invention provides that the coupling modules can be connected to the signal evaluation circuit and, in case of need, to the current connection and, in case of need, to the communication pathway via a plug-and-socket connection. It is appropriate that the relay means be connected to the communication pathway via a fixed wiring. However, a possibility of connecting the coupling module in a unitary manner may be provided within the set-up of the relay means. This requires that the coupling modules should also be of a unitary structure in regard of the positions of their coupling contacts and the dimensions.
According to an aspect of the invention, the communication pathway is a direct-current line in which an alarm signal of an alarm box causes an increase in current evaluated by the control centre on the line and the coupling module has a series connection which is comprised of a switch and a resistor and is connected between the conductors of the line wherein the design of the coupling module is such as to close the switch if the signal evaluation circuit produces a control signal. Therefore, with regard to the fire alarm system, the relay means functions like a push-button fire alarm box connected to a direct-current alarm line. Such fire alarm systems still are in use in many cases. Also, it is known for older fire alarm systems equipped with sensor elements to arrange a communication also via a direct-current line by a decrease in current or increase in current.
Push-button alarm boxes which operate mechanically are manufactured in large numbers. Many of these push-button alarm boxes contain contacts and are retrofitted later with “line modules” or “communication modules” for an adaptation to certain fire alarm lines or buses. This fact is utilized by the invention by using line modules or fire alarm buses on direct-current alarm lines for an adaptation to mechanically operating push-button fire alarm boxes. Therefore, the relay means employs such a line module which then will be used for communication of the wireless alarm boxes with the communication pathway.
The embodiment mentioned last can also be an aid in determining a malfunction of the wireless-coupled alarm boxes if the coupling module has a further series connection which is comprised of a resistor and a switch, is disposed within the path of a conductor of the direct-current line, and cuts off th
Crosland Donnie L.
Job Lizenz GmbH & Co. KG
Vidas Arrett & Steinkraus P.A.
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