Patent Publication Number: US-8125320-B2

Title: Fire alarm system

Description:
TECHNICAL FIELD 
     The present invention relates to a sounder fitted to an alarm device that gives an alarm by detecting various kinds of abnormalities such as fires, and outputs an alarm to notify the occurrence of an abnormality, based on the output from the alarm device. 
     BACKGROUND ART 
     In order to save a building and human lives from house fire, it is effective to install a fire detector that detects the occurrence of fire at an early stage and gives an alarm. For this purpose, when the fire detector installed in a monitored region detects fire, the fire detector outputs an alarm signal to sound an alarm bell or an alarm speaker, thereby notifying the occurrence of fire. 
     However, in a building having high sound insulation such as a hotel, even when the alarm bell installed on an access is sounded, the alarm sound is not easily audible by users within living rooms. To solve this inconvenience, a sounder (a base sounder) that is directly fitted to the fire detector within the living room and generates alarm sound based on the output from the fire detector is put into practical use. For example, U.S. Pat. No. 6,362,726 discloses a base sounder that can be fitted to a fire alarm system. According to such base sounder, the alarm sound can be output at the same position as the fire detector within the living room, thereby more securely achieving the fire alarm. 
     A configuration of the above conventional base sounder is explained.  FIG. 21  is a vertical cross-sectional view of the conventional sounders installed on the ceiling surface. As shown in  FIG. 21 , the conventional base sounder  100  is fitted to a ceiling surface  102  via a fitting base  101 . A fire detector  103  is connected to a lower end of the base sounder  100 . Electric constituent elements such as a circuit substrate  104  and a piezo element  105  are accommodated inside the base sounder  100 . Alarm sound output from the piezo element  105  is discharged to the outside of the base sounder  100 . A screw hole  106  being passed through is formed in the base sounder  100 . The base sounder  100  is fixed to the fitting base  101 , by having a long screw  107  inserted into this screw hole  106  and screwed into the fitting base  101 . The fire detector  103  is fixed to the base sounder  100 , by having an upper end of the fire detector  103  latched with the lower end of the base sounder  100 . 
     Wiring holes  108  and  109  being passed through respectively are formed at approximately the center of the plane surface (a position near the center of the plane surface approximately horizontal with the ceiling surface  102  as the installation surface (hereinafter, “the position near the center”)) of the fitting base  101  and the base sounder  100 , respectively. A lead wire  110  led out from the ceiling surface  102  is drawn to reach the lower surface of the base sounder  100 , via the wiring holes  108  and  109 . The lead wire  110  lead out in this way is connected to a connection terminal  111  provided on the lower surface of the base sounder  100 , with a screw. This connection terminal  111  is connected to a circuit substrate  104 , thereby supplying power to each electric constituent element of the base sounder  100 . A connection terminal  112  of the fire detector  103  is connected to the connection terminal  111 , thereby supplying power to each part of the fire detector  103 .
     Patent Document 1: U.S. Pat. No. 6,362,726   

     DISCLOSURE OF THE INVENTION 
     Problems to be Solved By the Invention 
     However, the conventional sounder of the base counter has various inconveniences attributable to the fitting structure. 
     For example, in the conventional installation operation of the base sounder, the fitting base exclusive for the base sounder is fixed to the installation surface of the ceiling surface or the like, and the base sounder is fixed to this fitting base. On the other hand, in the case of installing only the fire detector by omitting the base sounder, a fitting base exclusive for the fire detector different from the fitting base for the base sounder is fixed to the installation surface, and the fire detector is fixed to this fitting base. 
     As explained above, according to the conventional practice, the fitting base for installing the base sounder to the installation surface is different from the fitting base for installing only the fire detector to the installation surface. The installation operations are different accordingly, resulting in complex installation operations, and generating operation errors. Because the installation structures are different in this way, when it is desired to further fit afterward the base sounder to the monitored region in which only the fire detector is installed, the fitting base needs to be replaced, making it difficult to fit the base sounder afterward. Further, because the base sounder is screwed into the fitting base, screws and screw-fastening tools become necessary, resulting in complex fitting operation of the base sounder. 
     According to the conventional base sounder, the lead wire to supply power is passed through the base sounder. Therefore, the throughhole needs to be formed at approximately the center of the plane surface of the base sunder. Because the sound source of the piezo element cannot be disposed at approximately the center of the plane surface of the base sounder, uniform acoustic output in the directions around the base sounder cannot be achieved, resulting in the difficulty of improving the alarm output. 
     The present invention has been achieved in view of the above conventional problems of the sounder, and has an object of providing a sounder that increases the installation operation and the alarm output efficiency, by solving the various inconveniences attributable to the fitting structure. 
     Effects of the Invention 
     According to the sounder of the present invention, the output device-side connection terminal is connected to the base-side connection terminal of the fitting base, thereby making it possible to structurally and electrically connect the sounder to the fitting base. Therefore, screws and screw-fastening tools are not necessary at the time of fitting the sounder. As a result, the fitting operation of the sounder becomes easier. 
     Further, according to the sounder of the present invention, the second output-side connection terminal is connected to the alarm device-side connection terminal of the alarm device, thereby making it possible to structurally and electrically connect the alarm device to the sounder. Therefore, screws and screw-fastening tools are not necessary at the time of fitting the alarm device. As a result, the fitting operation of the alarm device becomes easier. 
     Further, according to the sounder of the present invention, the terminals are connected to each other, by sandwiching other plate between plural plates disposed approximately in parallel on the installation surface. Therefore, even when the own weights of the sounder and the alarm device are applied to a direction orthogonal with the installation surface, the plates can support the weights, thereby making it possible to structurally and electrically connect the sounder and the alarm device. 
     Further, according to the sounder of the present invention, the position and the shape of the output device-side connection terminal of the sounder are set approximately the same as the position and the shape of the base-side connection terminal of the fitting base. At the same time, the position and the shape of the second output device-side connection terminal of the sounder are set approximately the same as the position and the shape of the alarm device-side connection terminal of the alarm device. Therefore, the connection structure of the sounder to the fitting base, the connection structure of the alarm device to the fitting base, and the connection structure of the alarm device to the sounder can be made common to each other. Accordingly, any one of the sounder and the alarm device can be easily fitted to the same fitting base. For example, when the sounder is going to be further fitted after only the alarm device has already been installed, the fitting operation becomes easier, without requiring the replacement of the fitting base. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a base sounder according to a first embodiment of the present invention together with a fire detector. 
         FIG. 2  is an exploded perspective view of the base sounder and the like shown in  FIG. 1 . 
         FIG. 3  is an enlarged perspective view of a fitting base observed from below. 
         FIG. 4  is an enlarged perspective view of a fitting base observed from above. 
         FIG. 5  is an enlarged perspective view of a base sounder observed from below. 
         FIG. 6  is an enlarged perspective view of a base sounder observed from above. 
         FIG. 7  is an exploded perspective view of the base sounder. 
         FIG. 8  is an enlarged perspective view of a sounder body observed from above. 
         FIG. 9  is an exploded perspective view of the sounder body shown in  FIG. 8 . 
         FIG. 10  is a vertical cross-sectional view of the base sounder together with the fitting base and the fire detector. 
         FIG. 11  is a top plan view of a base cover observed from below. 
         FIG. 12  is a perspective view of the fire detector observed from above. 
         FIG. 13  is an enlarged perspective view of a connection terminal before the connection. 
         FIG. 14  is an enlarged perspective view of a connection terminal after the connection. 
         FIG. 15  is a perspective view of a wall sounder and the like according to a second embodiment of the present invention. 
         FIG. 16  is an exploded perspective view of the wall sounder and the like shown in  FIG. 15 . 
         FIG. 17  is a perspective view of the wall sounder observed from the inside. 
         FIG. 18  is a perspective view of a base beacon and the like according to a third embodiment of the present invention. 
         FIG. 19  is an exploded perspective view of the base beacon and the like shown in  FIG. 18 . 
         FIG. 20  is a perspective view of the base beacon observed from above. 
         FIG. 21  is a vertical cross-sectional view of the conventional base sounder and the like installed on the ceiling surface. 
     
    
    
     DESCRIPTION OF REFERENCE NUMERALS 
     
         
           1 ,  102  Ceiling surface 
           2  Lead wire 
           3  Wall surface 
           10 ,  101  Fitting base 
           11 ,  106  Screw hole 
           11   a ,  13   c ,  21   c ,  22   a ,  28   c ,  32   b ,  107  Screw 
           12 ,  108 ,  109  Wiring hole 
           13  Base-side connection terminal 
           13   a ,  13   b ,  23   a ,  28   a ,  28   b ,  32   a ,  43   a ,  53   a ,  54   a ,  54   b  Plate 
           20 ,  100  Base sounder 
           21  Base cover 
           21   a ,  21   b  Interlocked pole 
           21   d  External edge 
           22  Sounder body 
           23 ,  43 ,  53  Output device-side connection terminal 
           25   a  Upper casing 
           25   b  Lower casing 
           25   c  Sound discharge opening 
           26 ,  104  Circuit substrate 
           26   a  Metal 
           27 ,  105  Piezo element 
           27   a  Resonance space 
           27   b  Amplifying space 
           28 ,  54  Second output device-side connection terminal 
           30 ,  103  Fire detector 
           31 ,  41 ,  51  Casing 
           32  Alarm device-side connection terminal 
           40  Wall sounder 
           42  External part 
           50  Base beacon 
           52  Clear lens 
           111  Connection terminal 
       
    
     BEST MODES FOR CARRYING OUT THE INVENTION 
     Embodiments of the present invention are explained below. Each embodiment relates to a sounder, and the sounder is connected to an alarm device that detects an abnormality in a monitored region. When an abnormality is detected by this alarm device, the sounder receives the input of a signal output from the alarm device, and outputs various predetermined alarm outputs. 
     A specific content of a region and an object monitored by the alarm device connected to the sounder is optional. For example, a fire detector that detects fire, a gas leakage detector that detects a gas leakage, and a composite fire and a gas-leakage detector that detects both fire and gas are the objects to be monitored. 
     A specific form of the alarm carried out by the sounder is optional, and the sounder can output alarm sound or an alarm display. In the case of outputting the alarm sound, a kind of the alarm sound and a specific sound source are also optional. For example, a speaker and a piezo element can be used to output buzzer sound, and the speaker and a sound combining unit can be used to output a sound composite message. In the case of carrying out the alarm display, a kind of the alarm display and a specific light source are also optional. For example, a flickering display and a lighting display are carried out using an LED (Light Emitting Diode) or a laser semiconductor. This sounder can be fitted to an optional installation surface, such as a ceiling surface and a wall surface. 
     The sounder in each embodiment has a part of a main characteristic in the fitting structure, thereby improving the fitting efficiency. Schematically, a structural and electrical connection structure between the fitting base and the sounder, between the sounder and the fire detector, and between the fitting base and fire detector, respectively are made common. Therefore, the fire detector can be fitted to the sounder in the same order to that of fitting the sounder to the fitting base. Further, the fire detector can be directly fitted to the same fitting base. By making the fitting method common, the fitting order can be also made common to the fitting of only the fire detector to the fitting base and to the sequential fitting of the sounder and the fire detector to the fitting base. 
     The alarm output efficiency of the sounder according to each embodiment is improved by improving the fitting structure. Schematically, the formation of the throughhole at approximately the center of the plane surface of the sounder to connect the lead wire is not necessary. Accordingly, the sound source and the light source can be disposed at the center position of the plane surface, thereby improving the alarm effect. Each embodiment having a part or the whole of this characteristic is explained in detail. 
     First Embodiment 
     First, a first embodiment of the present invention is explained. The first embodiment relates to a sounder (hereinafter, referred to as “base sounder”) that is connected to a fire detector as an alarm device and outputs alarm sound based on the output from the fire detector. 
     A configuration of each part is explained first.  FIG. 1  is a perspective view showing the base sounder according to the first embodiment together with the fire detector and the like, and  FIG. 2  is an exploded perspective view of the base sounder and the like shown in  FIG. 1 . As shown in these drawings, a fitting base  10  is fixed to a ceiling surface  1  which is the installation surface, and a base sounder  20  is fitted to a lower part of the fitting base  10 . A fire detector  30  is connected to a further lower part of the base sounder  20 . In other words, the base sounder  20  is disposed to be sandwiched between the fitting base  10  and the fire detector  30 . In the first embodiment, for the convenience of the explanation, a direction approaching the ceiling surface  1  from the base sounder  20  is called “above”, and a direction leaving away from the ceiling surface  1  is called “below”, when necessary. When a surface other than the ceiling is set as an installation surface, the “above” can be regarded as a direction of approaching the installation surface, and “down” can be regarded as a direction of leaving away from the installation surface. 
       FIG. 3  is an enlarged perspective view of the fitting base looked at from below, and  FIG. 4  is an enlarged perspective view of the fitting base (a part of the screws and the lead wire are omitted) looked at from the above. The fitting base  10  is formed approximately in a plate shape as a whole, and includes a pair of screws  1 , a wiring hole  12 , and plural base-side connection terminals  13 . Each screw hole  11  is a throughhole to fix to fix the fitting base  10  to the ceiling surface  1 . When a screw  11   a  is inserted into the screw hole  11  and is screwed into the ceiling surface  1 , the fitting base  10  can be fixed to the ceiling surface  1 . This screw hole  11  is formed as a long hole. Along the longitudinal direction of the long hole, the fitting position of the fitting base  10  to the ceiling surface  1  can be easily adjusted. The wiring hole  12  is provided at approximately the center position of the plane surface of the fitting base  10 . The lead wire  2  led out from the ceiling surface  1  can be inserted into the wiring hole  12 , and drawn toward the base-side connection terminal  13 . The end part of the core line of the lead wire  2  drawn in this way is fixed to the fitting base  10  with a screw  13   f  that is electrically connected to the base-side connection terminal  13 . 
     The base-side connection terminal  13  is an electric connecting unit to receive power from the lead wire  2  and to input and output a signal to and from the base sounder  20  or the fire detector  30 . Further, the base-side connection terminal  13  functions as a connecting unit to carry out a structural connection between the fitting base  10  and the base sounder  20  or the fire detector  30 . Specifically, the base-side connection terminal  13  is configured to have two metal plates  13   a  and  13   b , disposed in approximately parallel on the ceiling surface  1  as the installation surface (i.e., disposed to be approximately orthogonal with a detachable direction of the base sounder  20 ), superimposed vertically. The base-side connection terminal  13  is fixed to the lower surface of the fitting base  10  with a screw  13   c.    
     A plate  23   a  of each output device-side connection terminal  23  described later of the base sounder  20  is sandwiched between the two plates  13   a  and  13   b , thereby structurally and electrically fixing the base sounder  20  to the fitting base  10 . Alternatively, by sandwiching between the two plates  13   a  and  13   b , a plate  32   a  of an alarm device-side connection terminal  32  described later of the fire detector  30 , the fire detector  30  can be structurally and electrically fixed to the fitting base  10 . Particularly, an end part  13   d  of the non-fixed side of the plate  13   a  is slightly bent downward, and the other plates  23   a  and  32   a  can be smoothly inserted into between the plates  13   a  and  13   b . An end part  13   e  of the non-fixed side of the plate  13   b  is slightly bent to allow the end part  13   e  to be inserted into between the plates  13   a  and  13   b . Based on the elastic repulsive force of the end part  13   e , the end part  13   e  is biased toward the plate  13   a , thereby securely maintaining a contact between the plates  13   a  and  13   b  and the other plates  23   a  and  32   a . A specific connection method is described later. 
     The base sounder  20  is explained next.  FIG. 5  is an enlarged perspective view of the base sounder looked at from below,  FIG. 6  is an enlarged perspective view of the base sounder looked at from the above, and  FIG. 7  is an exploded perspective view of the base sounder. As shown in these drawings, in outline, the base sounder  20  is configured to include a base cover  21  and a sounder body  22 . 
     Among of them, the base cover  21  covers approximately the whole of the fitting base  10  to improve design, dust prevention, and acoustic characteristic, by not exposing the fitting base  10  to the outside. Specifically, as shown in  FIG. 6 , the base cover  21  is formed in a hollow cup shape having a slightly larger diameter than that of the fitting base  10 , thereby making it possible to accommodate the fitting base  10  within the base cover  21 . 
     The output device-side connection terminals  23  are provided on the upper surface of the base cover  21 . Each output device-side connection terminal  23  is an electric connecting unit to receive power from the fitting base  10  and to input and output a signal to and from the fitting base  10 . The output device-side connection end  23  also functions as a connecting unit to structurally connect the base cover  20  to the fitting base  10 . Specifically, the output device-side connection terminal  23  is formed with one metal plate  23   a  disposed approximately parallel with the ceiling surface  1 . The plate  23   a  is disposed with a distance slightly above the upper surface of the base cover  21 , and is fixed to the base cover  21  with a screw  24  at the end of the base cover  21 . This plate  23   a  is sandwiched between the two plates  13   a  and  13   b  of the base-side connection terminal  13  shown in  FIG. 3 , thereby structurally and electrically fixing the base sounder  20  to the fitting base  10 . A specific connection method is described later. 
     The sounder body  22  is explained next.  FIG. 8  is an enlarged perspective view of the sounder body looked at from the above,  FIG. 9  is an exploded perspective view of  FIG. 8 , and  FIG. 10  is a vertical cross-sectional view showing the base sounder together with the fitting base and the fire detector. The sounder body  22  accommodates main electric structural elements of the base sounder  20 , and corresponds to the output body in claims. Specifically, the sounder body  22  is formed in a hollow disk shape having a diameter approximately the same as that of the fire detector  30  shown in  FIG. 1 , by combining an upper casing  25   a  and a lower casing  25   b . A circuit substrate  26  is accommodated within the sounder body  22 . Electric structural elements of the base sounder  20 , such as a central control unit and a power control unit (not shown), for example, are disposed on the circuit substrate  26 . A piezo element  27  as a sound source of alarm sound is disposed at an upper position at approximately the center of the plane surface of the sounder body  22 . The piezo element  27  is electrically connected to the circuit substrate  26 . When a voltage is applied to the piezo element  27 , the piezo element  27  is expanded and contracted to generate alarm sound. 
     Referring back to  FIGS. 5 and 7 , a second output device-side connection terminal  28  is provided on the lower surface of the sounder body  22 . The second output device-side connection terminal  28  is an electric connecting unit to supply power to the fire detector  30  shown in  FIG. 1  and to input and output a signal to and from the fire detector  30 . The second output device-side connection terminal  28  also functions as a connecting unit to structurally connect the sounder body  22  to the fire detector  30 . The position and the shape of the second output device-side connection terminal  28  of the sounder body  22  are approximately the same as the position and the shape of the base-side connection terminal  13  of the fitting base  10 . In other words, the second output device-side connection terminal  28  is configured to have two metal plates  28   a  and  28   b , disposed in approximately parallel on the ceiling surface  1  (not shown), superimposed vertically. The second output device-side connection terminal  28  is fixed to the lower surface of the sounder body  22  with a screw  28   c . The plate  32   a  of the detector-side connection terminal  32  described later of the fire detector  30  is sandwiched between the two plates  28   a  and  28   b , thereby structurally and electrically fixing the fire detector  30  to the base sounder  20 . Particularly, an end part  28   d  at the non-fixed side of the plate  28   a  is slightly bent downward, and can have the plate  32   a  smoothly inserted into between the plates  28   a  and  28   b . An end part  28   e  at the non-fixed side of the plate  28   b  is slightly bent to allow the end part  28   e  to be inserted into between the plates  28   a  and  28   b . Based on the elastic repulsive force of the end part  28   e , the end part  28   e  is biased toward the plate  28   a , thereby securely maintaining a contact between the plates  28   a  and  28   b  and the plate  32   a . A specific connection method is described later. 
     A mutual interlock structure between the base cover  21  and the sounder body  22  having the above configuration is explained next.  FIG. 11  is a top plan view of the base cover looked at from below. As shown in  FIGS. 7 to 11 , plural interlocked poles  21   a  and  21   b  in a hollow cylindrical shape extending toward the sounder body  22  are integrally provided on a side surface (a lower surface) facing the sounder body  22 , out of both side surfaces of the base cover  21 . Out of the plural interlocked poles  21   a  and  21   b , a part of the interlocked poles  21   a  facilitates positioning at the manufacturing time, and also functions as a hole to extract water when water drips from the back of the ceiling are pooled on the base cover and to insert a lock mechanism cancellation pin of the fitting base from the alarm device side. 
     The other interlocked poles  21   b  are formed at a position approximately corresponding to the plane surface position of the output device-side connection terminal  23  shown in  FIG. 6  and the plane surface position of the second output device-side connection terminal  28  shown in  FIG. 7 . On the other hand, as shown in  FIGS. 8 to 11 , the sounder body  22  is provided with screws  22   a  electrically connected from the circuit substrate  26 , and the screws  22   a  pierce through the upper casing  25   a  and are stretched upward. The screws  22   a  are inserted into the interlocked poles  21   b  shown in  FIG. 7 , and one end of each screw  22   a  is electrically connected to each output device-side connection terminal  23 . The screw  28   c  electrically connects the second output device-side connection terminal  28  to a metal  26   a  extending from the circuit substrate  26 . Based on this structure, the output device-side connection terminal  23 , the screw  22   a , and the second output device-side connection terminal  28  are electrically connected. By carrying out the electric connection via the interlocked poles  21   b  and the screws  22   a  in this way, the lead wire  2  shown in  FIGS. 2 and 3  does not need to be inserted into the base sounder  20 , and the throughhole for drawing the lead wire  2  into the base sounder  20  does not need to be formed. Therefore, degree of freedom of disposition of the piezo element  27  and other constituent elements shown in  FIG. 9  can be increased. 
     The acoustic structure of the base sounder  20  is explained next. As shown in  FIG. 10 , a resonance space  27   a  is formed within the sounder body  22 , and the piezo element  27  is disposed within the resonance space  27   a . The resonance space  27   a  amplifies the alarm sound generated from the piezo element  27 . The resonance space  27   a  is communicated to a sound discharge opening  25   c . The sound discharge opening  25   c  is the opening to discharge the alarm sound output from the piezo element  27  and amplified by the resonance space  27   a , toward an amplifying space  27   b  between the base cover  21  and the sounder body  22 . The discharged alarm sound is further amplified by the amplifying space  27   b . In other words, the cross section of the amplifying space  27   b  is formed to gradually become larger from the plane-surface center position toward the plane-surface external-side direction (in the left and right directions in  FIG. 10 ). The alarm sound is amplified based on the horn effect. The alarm sound amplified in this way is output from the space  27   b  to the outside of the base sounder  20 . 
     An external edge  21   d  of the base cover  21  is configured to have a gradually larger diameter toward the ceiling surface  1 , and forms a smooth inclined plane to reach the ceiling surface  1 . An angle of the external edge  21   d  formed with the ceiling surface  1  is determined so that the alarm sound led to the ceiling surface  1  along the external edge  21   d  is reflected from the ceiling surface  1  in high efficiency. Therefore, the alarm sound reaches the external edge  21   d  along the external side surface of the base cover  21 , is smoothly led to the ceiling surface  1  along the external edge  21   d , and is reflected to the monitored region from the ceiling surface  1  in high efficiency. 
     In the above structure, the throughhole to draw the lead wire  2  does not need to be formed on the base sounder  20 . Therefore, the resonance space  27   a , the piezo element  27 , and the discharge sound opening  25   c  are disposed at approximately the center position of the plane surface of the base sounder  20 . The amplifying space  27   b  is formed to approximately uniformly spread to the side around the approximately center position of the plane surface of the base sounder  20 . Therefore, the alarm sound is amplified and spread in good balance two-dimensionally. Because the alarm sound is approximately uniformly output around the base sounder  20 , the acoustic efficiency can be improved. 
     The fire detector  30  is explained next. The fire detector  30  can be configured approximately in the same manner as that of the conventional fire detector except a part specifically described. Explanations of the configuration approximately the same as that of the conventional fire detector will be omitted. As shown in  FIG. 1 , the upper part of a casing  31  of the fire detector  30  is formed in the hollow cup shape having approximately the same diameter as that of the sounder body  22  of the base sounder  20 . In the state that the fire detector  30  is fixed to the base sounder  20 , the side surface of the fire detector  30  and the side surface of the base sounder  20  are mutually on approximately the same plane, thereby generating a sense of unity in design. 
       FIG. 12  is a perspective view of the fire detector looked at from the above. As shown in  FIG. 12 , the alarm device-side connection terminal  32  is provided on the upper surface of the fire detector  30 . The alarm device-side connection terminal  32  is an electric connecting unit that supplies power to the fire detector  30  and inputs and outputs a signal to and from the base sounder  20  or the fitting base  10 . The alarm device-side connection terminal  32  also functions as a connecting unit to structurally connect the fire detector  30  to the base sounder  20  or the fitting base  10 . Therefore, the position and the shape of the alarm device-side connection terminal  32  of the fire detector  30  are approximately the same as the position and the shape of the output device-side connection terminal  23  of the base cover  21  shown in  FIG. 6 . Specifically, the alarm device-side connection terminal  32  is formed with one metal plate  32   a  disposed approximately parallel with the ceiling surface  1  (not shown). This plate  32   a  is disposed with a slight distance from the upper surface of the fire detector  30 , and is fixed to the fire detector  30  with a screw  32   b  at the end part of the fire detector  30 . The plate  32   a  is sandwiched between the two plates  28   a  and  28   b  of the second output device-side connection terminal  28  of the base sounder  20  shown in  FIG. 7 , thereby structurally and electrically fixing the fire detector  30  to the base sounder  20 . Alternatively, the plate  32   a  is sandwiched between the two plates  13   a  and  13   b  of the base-side connection terminal  13  of the fitting base  10  shown in  FIG. 3 , thereby structurally and electrically fixing the fire detector  30  to the fitting base  10 . A specific connection procedure is described later. 
     A connection order of each part is explained in detail below. First, in  FIG. 3 , the fitting base  10  is pressed against the ceiling surface  1  from below, and the screw  11   a  is inserted into the screw hole  11  and is screwed into the ceiling surface  1 , thereby fixing the fitting base  10  to the ceiling surface  1 . The lead wire  2  led from the ceiling surface  1  is drawn downward through the wiring hole  12 , and is fixed to the fitting base  10  with the screw  13   f.    
     Next, the base sounder  20  is fitted. Because the base cover  21  and the sounder body  22  are mutually combined as a product in advance in  FIG. 2 , the combined base sounder  20  is pressed against the fitting base  10  from below. In this case, as shown in the enlarged perspective view of the connection terminal before the connection shown in  FIG. 13 , the plates  13   a  and  13   b  of the base-side connection terminal  13  of the fitting base  10  and the plate  23   a  of the output device-side connection terminal  23  of the base cover  21  are in the state approximately parallel with the ceiling surface  1 , respectively, that is, in the state of mutually approximately parallel state. Therefore, when the base sounder  20  is rotated by a predetermined angle along the ceiling surface  1  as the installation surface, the plate  23   a  rotated along this rotation is inserted into and sandwiched between the plates  13   a  and  13   b , as shown in the enlarged perspective view of the connection terminal after the connection shown in  FIG. 14 . In this sandwiched state, the output device-side connection terminal  23  is latched by the base-side connection terminal  13 . Therefore, the output device-side connection terminal  23  is in contact with the base-side connection terminal  13  to make both conductive, and the base sounder  20  can be electrically connected to the fitting base  10 . At the same time, the plates  13   a  and  13   b  and the plate  23   a  are disposed along the direction approximately in parallel with the ceiling surface  1  (approximately in the horizontal direction). As a result, the own weight of the base sounder  20  applied to the vertical direction is supported by the base-side connection terminal  13 . Consequently, the base sounder  20  can be structurally supported by the fitting base  10 , without using other fixing unit such as a screw. When the base sounder  20  is rotated in a direction opposite to that of fitting the base sounder  20 , the base sounder  20  can be easily extracted from the fitting base  10 . 
     Thereafter, in fitting the fire detector  30  to the base sounder  20  as shown in  FIG. 2 , the operation approximately the same as that of fitting the base sounder  20  to the fitting base  10  is carried out. In other words, the fire detector  30  is pressed against the base sounder  20  from below, and is rotated by a predetermined angle along the ceiling surface  1  as the installation surface. The plate  32   a  of the alarm device-side connection terminal  32  shown in  FIG. 12  rotated along this rotation is then inserted into and sandwiched between the plates  28   a  and  28   b  of the second output device-side connection terminal  28  of the sounder body  22  shown in  FIG. 7 . In this sandwiched state, the alarm device-side connection terminal  32  is latched by the second output device-side connection terminal  28 . Therefore, the alarm device-side connection terminal  32  is in contact with the second output device-side connection terminal  28  to make both conductive, and the fire detector  30  can be electrically connected to the base sounder  20 . At the same time, the plates  28   a  and  28   b  and the plate  32   a  are disposed along the direction approximately in parallel with the ceiling surface  1  (approximately in the horizontal direction). As a result, the own weight of the fire detector applied to the vertical direction is supported by the second output device-side connection terminal  28 . Consequently, the fire detector  30  can be structurally supported by the base sounder  20 , without using other fixing unit such as a screw. When the fire detector  30  is rotated in a direction opposite to that of fitting the fire detector  30 , the fire detector  30  can be easily extracted from the base sounder  20 . 
     On the other hand, at the time of directly fitting only the fire detector  30  to the fitting base  10  by omitting the base sounder  20 , the operation approximately the same as that of fitting the fire detector  30  to the base sounder  20  can be carried out. In other words, after the fitting base  10  is fitted to the ceiling surface  1 , the fire detector  30  is pressed against the fitting base  10  from below, and the fire detector  30  is rotated by a predetermined angle along the ceiling surface  1 . In this state, the plates  13   a  and  13   b  of the base-side connection terminal  13  of the fitting base  10  and the plate  32   a  of the alarm device-side connection terminal  32  of the fire detector  30  are mutually in a parallel state. Therefore, the plate  32   a  rotated along the rotation of the fire detector  30  are sandwiched between the two plates  13   a  and  13   b . In this sandwiched state, the alarm device-side connection terminal  32  is latched by the base-side connection terminal  13 . Therefore, the alarm device-side connection terminal  32  is in contact with the base-side connection terminal  13  to make both conductive, and the fire detector  30  can be electrically connected to the fitting base  10 . At the same time, the plates  13   a  and  13   b  and the plate  32   a  are disposed along the direction approximately in parallel with the ceiling surface  1  (approximately in the horizontal direction). As a result, the own weight of the fire detector  30  applied to the vertical direction is supported by the base-side connection terminal  13 . Consequently, the fire detector  30  can be structurally supported by the fitting base  10 , without using other fixing unit such as a screw. When the fire detector  30  is rotated in a direction opposite to that of fitting the fire detector  30 , the fire detector  30  can be easily extracted from the fitting base  10 . 
     Alternatively, the fire detector  30  can be first fitted to the base sounder  20 , and thereafter, these can be collectively fitted to the fitting base  10 . Further, only the base sounder  20  can be fitted to the fitting base  10 , and the fire detector  30  can be omitted. When the fire detector  30  is omitted in this way, the base sounder  20  can be first fitted to the fitting base  10 , and thereafter, a cover (not shown) can be covered on the base sounder  20 . With this arrangement, by covering the second output device-side connection terminal  28  and the like, safety and design can be secured. When only the fire detector  30  is already provided on the fitting base  10  at a high position, an extractor capable of holding the fire detector  30  and the base sounder  20  is fixed to the front end of a long pole. By using this extractor, the fire detector  30  is extracted, and thereafter, the base sounder  20  and the fire detector  30  can be sequentially fitted. In this way, each device can be fitted and extracted by only rotating each part, thereby facilitating the operation at a high place. 
     As described above, according to the first embodiment, each part can be sequentially fitted in approximately the same order. Therefore, the fitting operation can be made common. Further, regardless of presence of the base sounder  20 , the same fitting base  10  can be used, thereby facilitating the fitting operation. Further, because screw cramp is not necessary to fit the base sounder  20  and the fire detector  30 , screws and work tools are not necessary. As a result, the fitting operation is further facilitated. 
     Second Embodiment 
     A second embodiment is explained next. The second embodiment relates to a sounder (hereinafter, “wall sounder”) that is fixed to a wall surface and outputs alarm sound based on the control of a receiving unit which receives the output from a fire detector fitted to a separate position. Configurations not particularly explained below are same as those of the first embodiment, and the configurations substantially the same as those of the first embodiment are assigned with like names or signs as those in the explanations of the first embodiment as necessary, and their explanations will be omitted. 
       FIG. 15  is a perspective view of a wall sounder or the like according to the second embodiment, and  FIG. 16  is an exploded perspective view of the wall sounder and the like. As shown in these drawings, the fitting base  10  is fixed to a wall surface  3  as the installation surface, and a wall sounder  40  is fitted to this fitting base  10 . In the second embodiment, for the convenience of the explanation, a direction approaching the wall surface  3  from the wall sounder  40  is called “inside”, and a direction leaving away from the wall surface  3  is called “outside”, when necessary. When a surface other than the wall surface  3  is set as an installation surface, the “inside” can be regarded as a direction of approaching the installation surface, and “outside” can be regarded as a direction of leaving away from the installation surface. 
     The fitting base  10  is configured in a similar manner to that of the first embodiment, and the base-side connection terminal  13  is provided on the external surface. The lead wire  2  led from the wall surface  3  is connected to the base-side connection terminal  13 . 
     The wall sounder  40  is configured to accommodate a piezo element (not shown) as a sound source, in a casing  41  having an external diameter covering approximately the whole fitting base  10 . An external part  42  of the casing  41  is formed in a shape similar to that of a loud speaker to have a larger width toward the outside. Alarm sound output from the piezo element is guided to the external part  42  via the opening (not shown), is amplified by the external part  42 , and is output to the outside. 
       FIG. 17  is a perspective view of the wall sounder looked at from the inside. An output device-side connection terminal  43  formed at the position and in the shape similar to those of the output device-side connection terminal  23  of the base sounder  20  in the first embodiment is provided on the internal surface of the wall sounder  40 . The output device-side connection terminal  43  is configured to include plates  43   a  disposed in approximately parallel on the wall surface  3  as the installation surface, in the state as shown in  FIG. 17 . Therefore, when the wall sounder  40  is pressed against the fitting base  10  and is rotated by a predetermined angle along the wall surface  3 , each plate  43   a  rotated along this rotation is inserted into and sandwiched between the plates  13   a  and  13   b  of the base-side connection terminal  13 , thereby fixing the wall sounder  40  to the fitting base  10 . When the wall sounder  40  is rotated to a direction opposite to the fitting direction, the wall sounder  40  can be easily extracted from the fitting base  10 . 
     Conventionally, a fitting base (not shown) exclusive for the wall sounder  40  is fixed to the wall surface, and the wall sounder  40  is fixed to this exclusive fitting base. Specifically, the lead wire  2  led from the wall surface  3  is passed through the exclusive fitting base and drawn, and is connected to the connection terminal provided on the internal surface of the wall sounder  40 . Thereafter, a long screw is inserted into the wall sounder  40  from the outside, passed through the wall sounder  40 , and is screwed into the fitting base, thereby fixing the wall sounder  40 . On the other hand, according to the second embodiment, the base sounder  20  and the fire detector  30  of the first embodiment can be fitted to the fitting base  10 , and the wall sounder  40  can be fitted in a similar order to that of fitting the base sounder  20  and the fire detector  30 . Therefore, the fitting of the wall sounder  40  can be made common to the fitting of the base sounder  20  and the fire detector  30 . The wall sounder  40 , the base sounder  20 , and the fire detector  30  can be easily exchanged. Because screw cramp is not necessary to fit the wall sounder  40 , screws and work tools are not necessary. As a result, the fitting operation is further facilitated. 
     Third Embodiment 
     A third embodiment is explained next. In the third embodiment, a sounder is further fixed to a base sounder fixed on the ceiling surface. The third embodiment relates to the sounder (hereinafter, “base beacon”) that displays an alarm based on the output from the fire detector. Configurations not particularly explained below are same as those of the first embodiment, and the configurations substantially the same as those of the first embodiment are assigned with like names or signs as those in the explanations of the first embodiment as necessary, and their explanations will be omitted. 
       FIG. 18  is a perspective view of the base beacon according to the third embodiment, and  FIG. 19  is an exploded perspective view of the base beacon and the like shown in  FIG. 18 . As shown in  FIGS. 18 and 19 , the fitting base  10  is fixed to the ceiling surface  1  as the installation surface, and the base sounder  20  is fitted to the lower part of the fitting base  10 . A base beacon  50  is fitted to the lower part of the base sounder  20 . The fire detector  30  is further fitted to the lower part of the base beacon  50 . The fitting base  10 , the base sounder  20 , and the fire detector  30  can be configured approximately in the same manner as that explained in the first embodiment, and therefore, their explanations will be omitted. 
     The base beacon  50  is configured to include an LED (not shown) as a light source, in a cylindrical casing  51  having an external diameter approximately the same as that of the base sounder  20 . A clear lens  52  is engaged on the whole periphery of the side part of the casing  51 . Light emitted from the LED is discharged to the outside via this clear lens  52 . 
       FIG. 20  is a perspective view of the base beacon looked at from the above. As shown in  FIG. 20 , an output device-side connection terminal  53  is provided on the upper surface of the base beacon  50 , at a similar position and in a similar shape to those of the output device-side connection terminal  23  of the base sounder  20  according to the first embodiment. This output device-side connection terminal  53  is configured to have plates  53   a . The plates  53   a  are disposed approximately in parallel on the ceiling surface  1  as the installation surface, in a state that the base beacon  50  is disposed as shown in  FIG. 19 . The base beacon  50  is pressed against the base sounder  20  from below, and is rotated by a predetermined angle along the ceiling surface  1 . Each plate  53   a  of the output device-side connection terminal  53  rotated along this rotation is then inserted into and sandwiched between the plates  28   a  and  28   b  of the second output device-side connection terminal  28  of the plate  53   a , thereby fixing the base beacon  50  to the base sounder  20 . In a similar order to this fitting order, the base beacon  50  can be also directly fitted to the fitting base  10 , by avoiding the base sounder  20 , like in the case of the fire detector  30  in the first embodiment. When the base beacon  50  is rotated in the direction opposite to that of fitting the base beacon  50 , the base beacon  50  can be easily extracted from the base sounder  20 . 
     As shown in  FIG. 19 , on the lower surface of the base beacon  50 , second output device-side connection terminals  54  are provided at a position and in a shape similar to those of the second output device-side connection terminals  28  of the base sounder  20  in the first embodiment. Each second output device-side connection terminal  54  is configured by combining two plates  54   a  and  54   b . The plates  54   a  and  54   b  are disposed approximately in parallel on the ceiling surface  1  as the installation surface, in a state that the base beacon  50  is disposed as shown in  FIG. 19 . The fire detector  30  is pressed against the base beacon  20  from below, and is rotated by a predetermined angle along the ceiling surface  1 . Each plate  32   a  of the alarm device-side connection terminal  32  (not shown) rotated along this rotation is then inserted into and sandwiched between the plates  54   a  and  54   b  of the second output device-side connection terminal  54 , thereby electrically and structurally fixing the fire detector  30  to the base beacon  50 . When the fire detector  30  is rotated in the direction opposite to that of fitting the fire detector  30 , the fire detector can be easily extracted from the base beacon  50 . 
     Conventionally, the base beacon  50  is fitted to the fitting base  10  common to the fire detector  30 , in a shape similar to that of the fire detector  30 . Therefore, the base beacon  50  cannot be installed coaxially with the fire detector  30 . However, in the third embodiment, based on the employment of the connection structure similar to that of the base sounder  20  in the first embodiment, the fire detector  30  can be also connected to the lower surface of the base beacon  50 . According to the above third embodiment, the base sounder  20  and the fire detector  30  of the first embodiment can be fitted to the fitting base  10 . In a similar fitting order, the base beacon  50  can be also fitted to the fitting base  10  and the base sounder  20 . Therefore, the fitting of the base beacon  50  can be made common to the fitting of the base sounder  20  and the fire detector  30 . The base beacon  50 , the base sounder  20 , and the fire detector  30  can be easily exchanged with each other. Further, because the fitting of the base beacon  50  does not require screw cramp, screws and work tools are not necessary, thereby further facilitating the fitting operation. 
     While each embodiment of the present invention has been described above, modifications and variations of specific configurations and methods of the present invention can be optionally made within the technical scope of the invention described in the claims. Such a modified example is explained below. 
     The configuration of each embodiment can be also applied to other embodiments. For example, in the first and the third embodiments, the fire detector  30  is disposed at the lowest part to increase the fire detection capacity. In order to maximize the alarm output effect, the fire detector  30  can be fixed to the fitting base  10 . The base sounder  20  and the base beacon  50  can be fixed to the lower part of the fire detector  30 . In this case, the second output device-side connection terminal  28  can be provided on the lower surface of the fire detector  30 . When the connection terminals shown in each embodiment are provided on the upper surface and the lower surface of various detectors having the heat and gas detecting functions, for example, these detectors can be combined according to need, and the terminal device having the composite function can be configured. 
     The connection terminals can take various positions and shapes other than those described in each embodiment. For example, one of the mutually connected connection terminals can be set as a male terminal used to connect the plug of household electric appliances, and the other connection terminal can be used as a female terminal that detachably receives the male terminal. In each embodiment, each part can be structurally and electrically connected using a connection terminal. However, it can be arranged such that the structural connection is carried out by fastening with screws like the conventional practice, and only the electric connection is carried out in the connection structure according to the configurations of the present invention. 
     The problems to be solved by the present invention and the effects of the present invention are not limited to the above-described content. The present invention can also solve problems not described above, and can have effects not described above. The present invention also solves only a part of the described problems, and has only a part of the effects described above. For example, even when the connection structure of each part cannot be made completely common, the object of the present invention can be achieved so long as when the connection efficiency is slightly improved from the conventional efficiency. 
     The structure examples, and size relationships, positional relationships, and thicknesses of the parts described in the above document and drawings are simply illustrative, and these can be optionally changed unless otherwise specified. 
     INDUSTRIAL APPLICABILITY 
     As described above, the sounder according to the present invention can be used to give alarm based on the output from the alarm device. Particularly, the sounder according to the present invention is useful to improve the operation of fitting the sounder to the installation surface and the output efficiency of alarm from the sounder.