Abstract:
An exit path indicating device incorporates at least a first port for receiving an alarm indicating signal. In normal operation upon receipt of the alarm indicating signal, the device outputs a visual or an audible, or both, indicator of the presence of an exit or egress path for use in evacuating the region. A second port disables the operation of the device. The second port can be coupled to a local sensor which provides an indication of a hazardous or alarm condition adjacent to or on the exit or egress path. If the sensor is indicating the presence of a hazardous or alarm condition, the indicating device can be disabled.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention pertains to an indicating devices of a type used in alarm systems for indicating exit paths in the event of an alarm condition. More particularly, the invention pertains to such devices which can be disabled in the event that the respective exit or output path is unsuited for use.  
       BACKGROUND  
       [0002]     It has been known to install evacuation path or exit path indicating devices in regions being monitored to assist individuals in the respective regions to evacuate the region in the event of an alarm condition. Such devices provide either visual indicators, such as strobe lights or other types of exit identifying symbols, or audible indicators, such as sounders, or both, of the presence of an exit or an evacuation path. One known type of device is a broadband directional sounder.  
         [0003]     Unfortunately at times when an alarm condition is present, such as a fire for example, one or more of the evacuation paths or exits might become unsuitable for use. Conditions that might result in unsuitability would include the presence of fire or smoke adjacent to, or, on the respective evacuation path or at the respective exit. It would be desirable to be able to provide supplemental information to individuals in the region as to the suitability of the various paths, or exits, for leaving the respective region. Preferably such information could be provided without substantially increasing the cost of the egress path indicating devices. Also, it would be preferably if such functionality could be readily incorporated into existing systems. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0004]      FIG. 1  is block diagram of an egress path indicating output device;  
         [0005]      FIG. 2  is a schematic diagram illustrating a detector coupled to an indicating device, as in  FIG. 1 , and in accordance with the invention;  
         [0006]      FIG. 3  is a top plan view of a system in accordance with the invention.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0007]     While this invention is susceptible of embodiment in many different forms, there are shown in the drawing and will be described herein in detail specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated.  
         [0008]      FIG. 1  is a block diagram of an exit path or egress indicating device  10 . The device  10  has a housing  12  which carries a control element  14 . Control element  14  could be implemented with a variety of technologies without departing from the spirit and scope of the invention. Electromechanical relays could be used as well as solid state circuitry all without limitation.  
         [0009]     Control element  14  receives two different input signals. An alarm input signal can be coupled to an alarm input port A for purposes of activating the device  10 . A second port E/D can be used to enable or disable the device  10  as described in more detail subsequently. Control element  14  is coupled to one or both of an exit or egress path audible indicating device  16  or a visual exit or path indicating device, such as a lighted symbol or strobe unit,  18 .  
         [0010]     As those that are skilled in the art will understand, in the presence of an alarm input, port A, the unit  10  provides audible output signals, which could include synthetic voice horns, sirens, or the like without limitation, via output device  16 , or, visual output indicators, such as by illuminating a symbol or flashing a strobe light, via output device  18  to indicate to individuals in the vicinity the location of an exit or egress path. As also would be known by those skilled in the art, the alarm input signal which would activate a plurality of devices, such as the device  10 , does not take into account the local conditions in the vicinity of the device  10  at that time. In the prior art, the devices  10  are automatically activated inspective of local conditions in response to the alarm input signal, port A.  
         [0011]      FIG. 2  illustrates an embodiment of the present invention wherein the exit or path indicating device  10  is coupled to an ambient condition detector  24  which could be locally positioned relative to the device  10 . The detector  24  could, for example, be a fire detector such as a smoke detector, flame, or gas detector without limitation.  
         [0012]     An output signal from the detector  24 , coupled via line  24   a  to the E/D port of the unit  10  can be used to disable the unit  10  in the presence of a locally sensed, hazardous, smoke or fire condition. For example, if the regional alarm system has activated the devices  10  via the port A, and, some of the devices  10  which would indicate an escape path are in the vicinity of the fire, it would be desirable to disable those devices so as to not cause individuals in the region to expose themselves to the fire.  
         [0013]     By coupling locally situated detectors, such as the detector  24  to the path indicating devices  10 , those devices which are adjacent to or near the fire condition would be disabled by the output, line  24   a  from the detector  24 . Hence, individuals in the region would not be attracted to that segment, path, or exit which would lead the person or persons toward or into smoke or fire.  
         [0014]      FIG. 3  illustrates a portion of the region R being monitored by a regional alarm system  30 . Alarm system  30 , as is conventional, incorporates a plurality of detectors  32  which might be dispersed throughout the region R.  
         [0015]     The detectors  32  can be coupled by a wired or wireless medium  34 , without limitation, to the alarm system  30 . Alarm system  30  evaluates signals received from the members of the plurality  32  and determines, for example due to the presence of flame or smoke that a fire condition exists in a portion of the region R.  
         [0016]     In response to such a determination, alarm system  30 , via, for example line  30   a  can activate one or a plurality  40  of exit indicating or evacuation path indicating devices, comparable to the device  10 . Each of the members of the plurality  40 , such as indicator  40 - 1 ,  40 - 2  . . .  40 -n is located so as to identify, illuminate or provide an audible indication of an evacuation path E, or exit through some or all of the region R.  
         [0017]     The members of the plurality  40 , each incorporates an alarm signal input port A which is coupled to the line  30   a . Hence, in a normal operation regional alarm system  30  can activate the members of the plurality  40  upon sensing an alarm condition somewhere in the region R. As noted above, this activation is without regard to local conditions in the vicinity of the units  40 -I.  
         [0018]     Supplementing the alarm indicating signal on the line  30   a , is a plurality of fire detectors  50 . The members  50 - 1 ,  50 - 2  . . .  50 -m are dispersed along portions of the evacuation route or path E and near the exit. The members of the plurality  50  provide feedback as to local smoke or fire related conditions on or adjacent to the pathway E, and adjacent to the exit. As described above relative to  FIG. 2 , the members of the plurality  50  can be used to disable some or all of the indicators of the plurality  40  depending on local smoke/fire conditions adjacent to, along or in the vicinity of an exit.  
         [0019]     As illustrated in  FIG. 3 , detectors  50 - 1  . . .  50 - 4  coupled to the E/D port of indicator or enunciator device  40 - 1 . If any of those detectors indicate a local alarm condition, which could be for example, sensed temperature, sensed smoke, sensed flame, sensed gases such as carbon dioxide, those detectors  50 - 1  . . .  50 - 4  which have detected a hazardous condition can each disable device  40 - 1  based on a local sensed condition.  
         [0020]     Similarly, detectors  50 - 5 ,  50 - 6  which are coupled to the E/D port of path indicating device  40 - 2  can disable the audible or visual output therefrom in the event of a hazardous condition on or in the vicinity of the pathway E in the immediate area of output device  40 - 2 . It will also be understood that the devices  50 - 1  . . .  50 - 4  could also be coupled to the E/D port of output device  40 - 2  without departing from the spirit and scope of the present invention.  
         [0021]     Similarly, output devices  40 - 3  . . .  40 -n have E/D ports coupled to a plurality of detectors  50 - 7  . . .  50 -m located along or adjacent to exit path E. Detectors  50 - 1 ,  50 -m are located in the vicinity of the exit itself. Any of the detectors  50 - 7  . . .  50 -m can disable any of the respective output indicating devices  40 - 3  . . .  40 -n.  
         [0022]     As it will be understood by those skilled in the art, one type of enable/disable port can have terminals which accept normally open and/or normally closed contacts. A change of state at one of these terminals, normally open contacts closing or normally closed contacts opening, causes the respective output indicating device to become disabled. For example, normally open or normally closed contacts from the respective detectors can be directly connected to this form of E/D input port. In the case of normally open contacts, the detectors can be wired or connected in parallel to the port in order to provide an “or” function for the outputs of the respective detectors. Where the contacts are normally closed, the detectors can be wired in series to the E/D port of the indicating device to provide the “or” function. As those of skill in the art will understand, the detectors of the plurality  50  would be coupled to the respective members of the plurality  40  in accordance with their respective protocols to provide the desired “or” functionality.  
         [0023]     From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.