Abstract:
An alarm indicating output appliance can be releasibly affixed to a mounting plate. The plate carries wire receiving terminals which couple to the appliance. In the absence of the appliance, at least two of the terminals can be short circuited.

Description:
FIELD 
     The invention pertains to alarm notification devices. More particularly, the invention pertains to such devices which releasibly engage a base which has been hardwired into an alarm system. 
     BACKGROUND 
     Power and or signaling wires for fire notification devices are usually connected directly to the product. The product is then attached to a mounting base. The fact that the product is directly wired makes it more difficult to replace a malfunctioning unit. Additionally, up to eight gage wires may be used to power the product. The direct wiring of so many large gage wires makes attachment of the product to the mounting base much more difficult. Furthermore, testing and troubleshooting the system is much more difficult. It is difficult to determine whether a system problem is product or wiring related. 
     There is thus a need for structures that facilitate such connections and disconnections. Further, it would be desirable to be able to more readily check wiring than has been possible in the past. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a multi-element apparatus in accordance with the invention; 
         FIG. 2  illustrates a speaker or a horn unit usable in connection with the apparatus of  FIG. 1 ; 
         FIG. 3  illustrates a strobe unit usable with the apparatus of  FIG. 1 ; 
         FIG. 4  is a view illustrating the elements of the apparatus of  FIG. 1  being positioned in contact with one another; 
         FIG. 5A  illustrates one pin configuration of an electrical unit in accordance with the invention; 
         FIG. 5B  illustrates a different pin configuration of an electrical unit in accordance with the invention; 
         FIG. 6  illustrates control circuitry and other elements of the unit of  FIG. 5A ; 
         FIG. 7  illustrates one of the elements of  FIG. 1  mounted on an electrical box and with wires coupled thereto; 
         FIG. 8A ,  8 B is an enlarged partial views of short circuited and open circuited terminals of an electrical unit such as the electrical unit of  FIG. 5A ; 
         FIG. 9  is a perspective view of one of the terminals usable in the electrical unit of  FIG. 8 ; and 
         FIG. 10  is a perspective view of another electrical terminal usable with the unit of  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     While embodiments of this invention can take many different forms, specific embodiments thereof are shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention, as well as the best mode of practicing same, and is not intended to limit the invention to the specific embodiment illustrated. 
     One embodiment of the invention includes a fire notification appliance and a mounting base. The mounting base carries wiring terminals. 
     The base can be mounted to an electrical junction box. Alarm system wires are connected to the wiring terminals of the base. The notification appliance makes contact with those terminals upon installation of the product to the base. That contact can be made through a variety of structures including pins, blades, and the like, all without limitation. 
     If the appliance needs to be replaced, it can be removed from the base and another can be put in its place, without detaching the power wires. The base can also contain a shorting contact spring connecting, for example, positive “in” and positive “out” terminals. This structure enables an installer to check for wiring continuity prior to installing the product, simplifying the installation process. 
     In one aspect of the invention, the shorting spring can have a locking feature that causes the contact to remain open if the product is removed. This would then cause an open circuit trouble condition at the fire panel alerting the proper personnel that a fire notification unit had been removed. 
     Finally, the wires can be neatly dressed into the box allowing ample room within the box and unimpeded product installation. 
     The mounting base could have several embodiments. First, it could be formed as an injection molded plastic part with metal terminals pressed into positions that are aligned with the power pins or blades emanating from the product. Another embodiment could include a metal plate with an insulated terminal block attached such that it aligns with the power pins. 
     The product could contain a printed circuit board to which power connection pins or blades are soldered either individually or as a pin header assembly. The pins or blades would protrude through a back protective cover of the appliance and extend far enough to make contact with the terminals on the base. The contact can be made by a variety of methods including a jack and plug style, or pressure/friction contact, etc. This contact provides power to the appliance. 
     In a disclosed configuration, the appliance can be moved into releasible engagement with the base along a line generally perpendicular to the base or along a line generally parallel to the base. In either embodiment, the appliance open circuits the shorting spring. 
     In another aspect of the invention, removal of the appliance can leave the spring in an open circuited state. The spring can be short circuited to check system wiring. 
       FIG. 1  illustrates an embodiment of the present invention, an apparatus  10 . The apparatus  10  includes a mounting plate generally indicated at  12  and an associated electrical unit indicated generally at  14 . The mounting plate  12  is of a type which could be releasibly attached to an electrical box into which electrical wires have been drawn. Such electrical wires could be associated with an alarm monitoring system with the wires particularly being associated with energizing and controlling alarm indicating output appliances such as horns, strobes, combination horn/strobes, loud speakers, and the like, all without limitation. 
     Electrical unit  14  is a representative one of the respective appliances. The unit  14  can be elongated, square, cylindrical or any other convenient shape without limitation. 
     The mounting plate  12  has a generally planar shape with a central section  16   a  which could be formed of molded plastic with various openings, such as  16   b  formed therein to make it convenient to attach the plate  12  to the respective electrical box. 
     The plate  12  also divides an internal opening  16   c  through which electrical wires noted above could be drawn and in turn connected to power supply terminals indicated generally at  18 . 
     The plate  12  can support various numbers of power supply terminals, the three terminals  18   a, b  and  c  illustrated in  FIG. 1  are representative only. Additional numbers such as five terminals can also be supported by the mounting plate  12 . Those of skill in the art will understand that the number of terminals is not a limitation of the present invention. 
     The terminals are illustrated as screw type terminals in the embodiment of  FIG. 1 . It will also be understood that other types of terminal configurations such as push in terminals and the like which don&#39;t necessarily require screws come within the spirit and scope of the present invention. The terminals  18  are metallic as is conventional. 
     Electrical unit  14  includes a hollow exterior housing  22   a  with a generally planar surface  22   b  which closes an open side of the housing  22   a . The representative electrical unit  14  illustrated in  FIG. 1  is a strobe unit. The member  22   b  can be used with a plurality of differed shaped housings  22   a  such elongated, square, cylindrical all without limitation. 
     Those of skill in the art will understand that the unit  14  can be placed on and connected to the plate  12 . The plate  12  supplies a convenient and advantageous structure wherein the electrical wiring associated with the alarm system is brought into the box, then through the opening  16   c  and connected to the terminals  18 . Some of the terminals  18  can provide electrical signals or electrical energy to the unit  14  all without limitation. 
     The unit  14  carries a plurality of contact pins  24  which extend through openings in the cover  22   b  of the housing  22   a . The pins  24  are coupled to electrical circuitry carried in the housing  22   a  which can for example energize the respective strobe light periodically as would be understood by those of skill in the art, activate a horn or a loud speaker if desired as well. 
       FIG. 2  illustrates a representative speaker or horn unit  14   a  which can be coupled to the plate  12  and powered off of the terminals  18 .  FIG. 3  illustrates a representative strobe  14   b  which can also be coupled to a plate such as the plate  12  and energized off of power supply terminals such as terminals  18 . 
     As illustrated in  FIG. 4 , contact pins  24  of unit  14  (as in  FIG. 1 ) can be brought into contact with the terminals  18  of the plate  12  via rotating the unit  14  in a direction indicated generally at  28 . The direction  28  while arcuate is not a limitation of the present invention. The plate  12  could be configured such that the unit  14  is linearly moved into contact with the plate  12 . In the configuration of  FIG. 4 , the unit  14  moves in a direction which is along a line which intersects the plate  12 . 
     Alternately to the configuration of  FIG. 4 , those of skill will understand that the unit  14  could be moved laterally relative to the plate  12  generally along a line which is parallel to plate  12 . The unit  14  can also be rotatably coupled to the plate  12  if desired. 
       FIG. 4  illustrates the plate  12  attached to a box B with wires W extending into the box B. The wires W extend through the opening  16   c  and can be coupled to the terminals  18 , best seen in  FIG. 7 . 
       FIG. 5A  illustrates a configuration of pins  24  with a plurality of pins, such as three pins extending from the surface  22   b  which closes the housing  22   a . A contact member  24   a  is adjacent to the connecting pins  24 . It will be understood that the exact shape of the pins  24  is not a limitation of the present invention. While illustrated cylindrically, other contact shapes and numbers of contacts come within the spirit and scope of the invention. 
       FIG. 5B  illustrates an alternate configuration of contact elements or pins  24   b  which includes five contact members. The five contact members  24   b  can be coupled to circuitry within the unit  14  which can carry both a strobe and an audio output device such as horn or loud speaker. An audio output adjustment element  22   b - 2  can be provided on the member  22   b - 1 . 
       FIG. 6  illustrates the unit  14  with the cover or housing  22   a  removed. As illustrated therein the plurality of contact pins  24  extends from the planar member  22   b . The member  22   b  also carries a reflector  30   a , a strobe light  30   b , and associated control circuitry  30   c . The control circuitry  30   c  which can include a power supply can receive electrical energy via the wires W and at least one of the members of the plurality  24 . 
       FIG. 7  illustrates the plate  12  attached to the box B with the wires W extending through the opening  16   c . As illustrated in  FIG. 7 , the plate  12  can be attached via screws such as screws S 1 , S 2  to the box B. 
     Relative to the terminals  18 , as best seen in  FIG. 8A , B, terminals  18   a ,  18   c  are substantially identical. Terminal  18   b  is unlike terminals  18   a ,  18   c . Both terminals  18   a ,  18   c  include a contact member, such as  18   a - 1 ,  18   c - 1  which extends laterally therefrom. Terminal  18   b  carries a multi-element structure  18   b - 1 . 
     Elements  18   a - 1 ,  18   c - 1  are best seen in  FIG. 9 . Element  18   b - 1  is best seen in  FIG. 10 . 
     As illustrated in  FIG. 9 , terminals such as  18   a ,  18   c  carry the integrally formed laterally extending contact member  18   a - 1 ,  18   c - 1 . They also carry a respective screw terminal such as  18   a - 2 ,  18   c - 2 . A slidable contact  18   a - 3 ,  18   c - 3  is positioned between the screw terminal such as  18   a - 2  and the laterally extending  18   a - 1 . The contacts  18   a - 3 ,  18   c - 3  slidably receive the members of the plurality  24 . 
     Relative to  FIG. 10 , the contact member  18   b - 1  has a U-shaped hook portion indicated generally at  18   b - 5  and a latchable contact portion  18   b - 6 . The contact portion  18   b - 6  has a short circuit state; illustrated in  FIG. 8A  relative to contact member  18   c - 1  and an open circuit state  FIG. 8B  where the member  18   b - 6  does not contact the member  18   c - 1 . 
     In the open circuit state, the latch mechanism  18   b - 5  holds the contact portion of  18   b - 6  in a retracted position relative to the contact  18   c - 1  thereby producing an open circuit state. The member  18   b - 6  is spring biased and can switch from the open circuit state to the closed circuit state, illustrated in  FIG. 8 , by displacing the latch member  18   b - 5  laterally relative to the contact member  18   b - 6 . As illustrated in  FIG. 10 , the contact member  18   b - 6  is in its short circuit position, see  FIG. 8 . 
     The terminals  18   b ,  18   c  operate in conjunction with a force applying member  24   a  but seen in  FIG. 5A , B, of the electrical unit  14 . As the electrical unit  14  engages the plate  12 , the member  24   a  displaces contact member  18   b - 6  moving same toward the latch member  18   b - 5 . The latch member engages the contact member  18   b - 6  and latches same into an open circuit condition. In this condition, the terminals  18   b ,  18   c  are open circuited relative to one another, and, the power supply and control circuitry  30   c  of the unit  14  can if desired, couple an electrical signal from one terminal to the other indicating that the unit  14  has been installed and is functioning properly. 
     When the unit  14  is removed from the base  12  the terminals  18   b ,  18   c  continue to remain open circuited. This results in a discontinuity in the respective wires and can be detected as indicative of a trouble condition caused by a missing electrical unit For test purposes, an installer can manually release contacting member  18   b - 6  from latch member  18   b - 5  to produce a short circuit condition between terminals  18   b, c . When the unit  14  is reinstalled on the base  12 , the open circuit condition results between terminals  18   b, c.    
     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.