Alarm device for use in a baby&#39;s diaper
FIELD OF THE INVENTION 
     The present invention relates to an alarm for use in a baby&#39;s diaper and, more particularly, to a diaper alarm in which a buzzer sounds after a fecal excretion is detected. 
     BACKGROUND OF THE INVENTION 
     Up to this time, a baby&#39;s excrement has been detected only by opening the baby&#39;s diaper, so that there were disadvantages such as conditions unsanitary for the baby and the potential for skin diseases. 
     Accordingly, one object of the present invention is to provide a device adapted to produce a prompt and reliable indication of the presence of excrement in a baby&#39;s diaper. 
     SUMMARY OF THE INVENTION 
     According to the present invention, the presence of the baby&#39;s excrement is indicated by the sounding of a buzzer provided in the diaper in response to detection of moisture from the excrement which is absorbed by the diaper. Thus, the baby can be effectively protected from unsanitary conditions and skin diseases. 
     The alarm device of the present invention is preferably sufficiently small as to be placed at the outer surface of the diaper or at the inner surface of the baby&#39;s panties, if desired. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be described according to the drawings, in which: 
     FIG. 1 is an exploded perspective view of an alarm device for use in baby&#39;s diaper and embodying the present invention; 
     FIG. 2 is a fragmentary perspective view of the alarm device of FIG. 1; 
     FIG. 3 is a sectional view of the alarm device in FIG. 1; 
     FIG. 4 is an enlarged view of part of FIG. 3; and 
     FIG. 5 is a schematic diagram of a circuit which is part of the device of FIG. 1. 
    
    
     DETAILED DESCRIPTION 
     As shown in FIGS. 1, 2, 3 and 4, an alarm device 3 has a housing which includes a case 1 and cover 2 having a circular, square, polygon or other shape perimeter, here, circular. A space 4 is formed between the case 1 and cover 2, and an insulated circuit board 5 having an electronic circuit Z thereon is disposed in the space 4. A detecting part 10 of ring shape and a detecting part 10&#39; of circular shape are concentrically set into recesses 11 and 11&#39;, respectively, and the ring shaped detecting part 10 and circular detecting part 10&#39; are electrically connected with the electronic circuit Z, the recesses 11 and 11&#39; being centrally formed in the case 1. 
     A buzzer X is secured to the inside of the cover 2 by securing the edges of the buzzer X to the cover inner surface around a round hole 12 formed in the center of the cover 2. 
     A number of projections 13 are formed on the case 1 along the outer edge of the detecting part 10 in order to prevent the case 1 from slipping. Two tie-rings 14 are furnished on opposite sides of the case 1. 
     As shown in FIG. 5, the circuit used in the alarm device 3 is designed so that electricity is supplied from the battery B to integrated circuit IC through the electric wires P 1  and P 3 , integrated circuit IC is connected by wires P 1  and P 2  to the detecting parts 10 and 10&#39;, and oscillator OSC is connected directly to the integrated circuit IC, and the terminal P of the integrated circuit IC is connected with the base b of a transistor TR. The collector c of transistor TR is connected to one end of the buzzer X, the other end of the buzzer X is connected to the battery B, a coil L is connected in parallel with the buzzer X, and the emitter e of the transistor TR is directly connected to the negative power supply terminal of the battery B. 
     The detecting parts 10 and 10&#39; are preferably made of a conductive metal, moisture which comes into contact therewith providing a path for the flow of electricity between the detecting parts 10 and 10&#39;. 
     In using the present invention, the alarm device 3 is positioned appropriately in a baby&#39;s diaper or panties so as to allow the detecting parts 10 and 10&#39; to contact the diaper. In placing the alarm device 3 inside of panties, the tie-rings 14 are used for securing it to the panties with some appropriate fastener. 
     When the baby relieves itself, moisture is absorbed by the diaper and the detecting parts 10 and 10&#39;  of the alarm device 3 detect the moisture and cause integrated circuit IC to send a signal to the base b of the transistor TR which is amplified by the transistor TR and causes the buzzer X to oscillate and produce an audible alarm indicating excrement is present. At this time, the coil L resonates with the buzzer X to make the alarm sound louder by increasing the voltage of the oscillations. 
     The oscillator OSC supplies a frequency required by the integrated circuit IC. 
     The alarm device 3 of the present invention produces the alarm by means of the electronic circuit Z which is placed in the space 4 formed between the case 1 and cover 2 and made with small dimensions, and the detecting parts 10 and 10&#39; are fixed in the recesses 11 and 11&#39;, respectively, to make the overall dimensions of the alarm device smaller. 
     As hereinbefore mentioned, the detecting parts 10 and 10&#39; contact the diaper during use so that the parts 10 and 10&#39; can detect any excrement immediately, and the buzzer X is secured inside the cover 2 and over a round hole 12 provided in the middle part of the cover 2. Thus, all the essential parts are put into the case 1 and cover 2, which are preferably made of flat plastic and of small size so that the alarm device is very handy to use and a baby can be protected from unsanitary conditions and skin diseases. 
     Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.