Abstract:
Provided is a float type drain trap improved in terms of opening and closing of a valve seat. In the prior art, the valve seat is opened and closed mainly by a self-weight of a float and buoyancy of a float main body, so the valve seat is often left in a half-open state, with opening and closing of the valve seat being rather equivocal. Afloat is accommodated in a case, and drain water allowed to flow into the case is enabled to be discharged by buoyancy acting on the float. By providing a magnet between the case and the float, an attraction force is generated, and an outlet port formed in the case is closed or opened based on the relationship between the buoyancy, the attraction force, and the positions where these forces are generated, thereby making it possible to retain and discharge the drain water.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a technique related to a float type drain trap, and more specifically, to a technique for discharging drain water accumulated in a drain trap by mainly utilizing a buoyancy and an attraction force of a magnet. 
         [0003]    2. Description of the Related Art 
         [0004]    In a conventional technique related to a method of discharging drain water and a float type drain trap, there is a case where a float  200 A is accommodated in a case  100 A. 
         [0005]    In the following, a method of discharging drain water and a float type drain trap according to the conventional technique will be described with reference to  FIG. 5 . In the drawing, reference symbol  100 A indicates a case, which is formed as an integral unit composed of a case main body  50 , a float bracket  7 , a valve seat  9 , and a manual valve  4  having an O-ring. The case main body  50  is formed as an integral unit composed of a first case  1 , a second case  2 , and a gasket  3 , and is perfectly sealed to prevent leakage of drain water except for an inlet port  50   a  and an outlet port  50   b  which are formed in the case main body  50 . 
         [0006]    Reference symbol  200 A denotes a float, which is formed as an integral unit composed of a float main body  5 , an arm  6 , and a rubber valve seat  8 . In this case, the arm  6  is formed in a substantially L-shaped configuration, and has at one end thereof the float main body  5  for generating a buoyancy when drain water allowed to flow in through the inlet port  50   a  formed in the case  100 A has been accumulated to a certain degree. The arm  6  has at the other end thereof the rubber valve seat  8  for opening and closing the valve seat  9  situated in the outlet port  50   b  formed in the case  100 A. Further, the arm  6  has at a bent portion thereof a rotation shaft  6   a , which is engaged with the float bracket  7  formed in the case  100 A, thereby making the entire float  200 A rotatable. 
         [0007]    Thus, when not much drain water has been flowed into the case  100 A yet, no buoyancy is applied to the float main body  5 , and the rubber valve seat  8  is held in intimate contact with the valve seat  9  by the self-weight of the float  200 A to keep the case in the closed state. When a lot of drain water has flowed into the case  100 A to attain a level not lower than a fixed position, the buoyancy is applied to the float main body  5 , and due to the buoyancy, the rubber valve seat  8  is separated from the valve seat  9  to bring the case into the open state. It should be noted, however, that due to the pressure of compressed air caused to flow into the case  100 A, the force acting on the valve seat  9  and the elastic force of the rubber valve seat  8  also influence the opening and closing of the valve seat  9 . 
         [0008]    The conventional method of discharging drain water and the conventional float type drain trap described above have the following problem. 
         [0009]    Since the opening and closing of the valve seat is effected mainly by virtue of the self-weight of the float and the buoyancy due to the float main body, the valve seat is often left in a half-opened state, the opening and closing of the valve seat being rather equivocal. 
       SUMMARY OF THE INVENTION 
       [0010]    To solve the above-mentioned problem, the present invention employs the following structures. A float type drain trap of the present invention is characterized by including a float formed as an integral unit having: an arm; a float main body provided at one end of the arm and capable of floating in water; a rubber valve seat provided at the other end of the arm; and a rotation shaft provided at a middle bent portion of the arm. Also, the float type drain trap of the present invention is characterized by including a case formed as an integral unit having: a case main body equipped with an inlet port through which drain water flows in and an outlet port through which drain water flows out; a valve seat situated in the outlet port; and a float bracket for retaining the rotation shaft to thereby make the float rotatable. In the float type drain trap, the rotation shaft is situated on the float bracket inside the case so that, when drain water has not flowed in to attain a fixed position inside the case, the rubber valve seat closes the valve seat by the self-weight of the float, and when drain water has flowed in to attain the fixed position inside the case, the rubber valve seat opens the valve seat by the buoyancy of the float main body. Further, the float type drain trap is characterized in that a magnet is arranged at some position on the arm between the float main body and the rotation shaft, and in that associated members causing an attraction force due to the magnet to be generated are arranged at some position inside the case. Still further, the float type drain trap is characterized in that the rubber valve seat closes or opens the valve seat based on moments as defined by the self-weight of the float, the buoyancy, the attraction force, and the positions where these forces are generated. Yet further, the float type drain trap is characterized in that the associated members are composed of a plate spring and a plate spring bracket supporting the plate spring at some position inside the case. Furthermore, the float type drain trap is characterized in that the plate spring bracket constitutes a constraining means for retaining the position of the plate spring when the plate spring is separated from the magnet. 
         [0011]    As is apparent from the above description, the present invention provides the following effects. 
         [0012]    First, by providing a float with a magnet, and by providing a case with a plate spring and a spring bracket for supporting the spring plate at some position inside the case, with the plate spring and the spring bracket constituting associated members, it is possible to prevent fine movements with respect to the opening and closing, thereby preventing occurrence of a half-open state. 
         [0013]    Second, due to the provision of the plate spring, it is possible to markedly prevent occurrence of a half-open state. 
         [0014]    Third, due to the provision of the plate spring bracket as a constraining means, it is possible to prevent, still more markedly, occurrence of a half-open state. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    In the accompanying drawings: 
           [0016]      FIG. 1  is a schematic view of a float type drain trap according to the present invention with the outlet port thereof closed; 
           [0017]      FIG. 2  is a schematic view of a float type drain trap according to the present invention with the outlet port thereof open; 
           [0018]      FIG. 3  is an explanatory view illustrating the relationship between the forces acting on a float constituting the float type drain trap of the present invention; 
           [0019]      FIG. 4  is a perspective view of an arm and a rubber valve seat according to the present invention; and 
           [0020]      FIG. 5  is a schematic view of a conventional float type drain trap with the outlet port thereof open. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0021]    In the following, an embodiment of the present invention will be described in detail with reference to the drawings. 
         [0022]    Here,  FIG. 1  is a diagram showing a float type drain trap according to the present invention with the outlet port thereof closed,  FIG. 2  is a diagram showing a float type drain trap according to the present invention with the outlet port thereof open,  FIG. 3  is a diagram illustrating the relationship between the forces acting on the float constituting the float type drain trap of the present invention, and  FIG. 4  is a diagram showing an arm and a rubber valve seat according to the present invention. 
         [0023]    As shown in  FIGS. 1 ,  2 , and  3 , reference symbol  100 A denotes a case, which is formed as an integral unit composed of a case main body  50 , a float bracket  7 , a valve seat  9 , a stay  16 , a washer  18 , a nut  19 , a plate spring bracket  15 , a fixing screw  17 , and a plate spring  14 . The case main body  50  is formed as an integral unit composed of a first case  1 , a second case  2 , and a gasket  3 , and is perfectly sealed to prevent leakage of drain water except for an inlet port  50   a  and an outlet port  50   b  which are formed in the case main body  50 . 
         [0024]    Reference symbol  200 A denotes a float, which is formed as an integral unit composed of a hollow float main body  5 , an arm  20 , an adjustment screw  10 , a nut  11 , a magnet seat  12 , a magnet  13 , and a rubber valve seat  8 . In this example, the arm  20  has a substantially L-shaped configuration, and has at one end thereof the float main body  5 , which generates buoyancy F when drain water allowed to flow in through the inlet port  50   a  formed in the case  100 A has been accumulated to a certain degree. The arm  20  has at the other end thereof the rubber valve seat  8  for opening and closing the valve seat  9  situated in the outlet port  50   b  formed in the case  100 A. The arm  20  has at a bent portion  20   b  thereof a rotation shaft  20   a  engaged with the float bracket  7  formed in the case  100 A, thereby making the entire float  200 A rotatable. As shown in  FIG. 4 , the rotation shaft  20   a  protrudes from both sides of the bent portion  20   b.    
         [0025]    It should be noted, however, that the configuration of the arm  20  is not restricted to the substantially L-shaped one; it may also be a substantially U-shaped one, etc. The angle of the bent portion  20   b  of the arm  20  may be 90° or more, or 90° or less. In addition, when the rubber valve seat  8  keeps the valve seat  9  in the closed state, the arm  20  may extend parallel to the water surface L; however, the arm  20  may extend so as not to be parallel to the water surface. Further, the arm  20  may also be formed as a flat plate of a substantially I-shaped configuration. Further, instead of being situated coaxially, the rubber valve seat  8  and the valve seat  9  may be situated so as to be perpendicular to each other. 
         [0026]    When drain water flows into or out of the case  100 A, the entire float  200 A rotates around the rotation shaft  20   a , thereby enabling the rubber valve seat  8  to open and close the valve seat  9 . 
         [0027]    The arm  20 , which constitutes the float  200 A, has, in the portion thereof between the float main body  5  and the rotation shaft  20   a , the adjustment screw  10 , the nut  11 , the magnet seat  12 , and the magnet  13 , which are arranged so as to be integral with the arm  20 . 
         [0028]    In particular, the nut  11  and the magnet seat  12  are situated with the arm  20  therebetween, and these three components are fixed together through threaded engagement using the adjustment screw  10 , and the magnet  13  and the magnet seat  12  are fixed together by an absorption of the magnetic force. Further, the adjustment screw  10  serves to adjust the distance between the magnet  13  and the plate spring  14 . 
         [0029]    The plate spring  14  has a substantially L-shaped configuration, and is fixed to the J-shaped plate spring bracket  15  by a fixing screw  17 . The plate spring bracket  15  is fixed to the stay  16  by the washer  18  and the nut  19 . The stay  16  is fixed to the lower portion of the case main body  50  through threaded engagement. 
         [0030]    It should be noted, however, that the configuration of the plate spring  14  is not restricted to the substantially L-shaped one. It may also be formed as a flat plate of a substantially I-shaped configuration or some other configuration. Further, also regarding the configuration of the plate spring bracket  15 , it need not be restricted to the substantially J-shaped one. It may also be of a substantially L-shaped configuration or some other configuration. 
         [0031]    Here, when the plate spring  14  is attracted by the magnetic force of the magnet  13 , the plate spring bracket  15  also serves as a constraining means, which prevents the right-angle portion of the substantially L-shaped plate spring  14  from assuming an angle equal to or larger than 90 degrees due to the attraction by the magnetic force. 
         [0032]    In the following, the operation of the method of discharging drain water and the float type drain trap of the present invention, constructed as described above, will be illustrated. 
         [0033]    First, drain water flows into the case  100 A through the inlet port  50   a . When no or little drain water has flowed into the case  100 A, the rubber valve seat  8  and the valve seat  9  are held in intimate contact with each other to be closed by means of the arm  20  rotatable around the rotation shaft  20   a  formed at the bent portion  20   b  of the arm  20  by a force mainly attributable to the self-weight of the float  200 A and to the attraction force of the magnet  13 . In this case, the water surface L is as shown in  FIG. 3 , which also applies to  FIGS. 1 and 2 . 
         [0034]    As the amount of drain water in the case  100 A increases, a buoyancy F is generated to a degree corresponding to the amount of drain water displaced by the hollow float main body  5 . This will be illustrated with reference to  FIG. 3 . Since the float main body  5  is a sphere, the buoyancy F is applied upwardly toward the center of the sphere. In contrast, the self-weight G of the float  200 A as a whole is exerted downwardly. 
         [0035]    The following equation 1 holds true mainly based on the attraction force exerted between the magnet  13  attached to the arm  20  and the plate spring  14  attached to the case  100 A. 
         [0000]        M =(the buoyancy  F  of the float main body 5)×Sin α× X −(the self-weight  G  of the float 200 A )×Sin β× Z −(the attraction force of the magnet 13)× Y +(the elastic force of the rubber valve seat 8)× K −(the sectional are a of the flow path of the valve seat 9)×(the compressed air pressure)× K,   [Equation 1] 
         [0000]    where X: the minimum distance between the rotation shaft  20   a  and the center of the buoyancy F of the float main body  5  as measured along the arm  20  or an extension thereof; 
         [0036]    Y: the distance between the rotation shaft  20   a  and the center of the magnet  13  on the arm  20 ; 
         [0037]    Z: the minimum distance between the rotation shaft  20   a  and the center of the self-weight G of the float  200 A as measured along the arm  20  or an extension thereof; 
         [0038]    K: the distance between the rotation shaft  20   a  and the center of the rubber valve seat  8  on the arm  20 ; 
         [0039]    α: the angle made by the vertical line along which the buoyancy is generated and the arm; and 
         [0040]    β: the angle made by the vertical line along which the self-weight is generated and the arm. Here, it is actually possible for the buoyancy F, the self-weight G, and the arm  20  to be in the same plane. In this case, α=β is established. 
         [0041]    Thus, when the value of M is negative, the rubber valve seat  8  closes the valve seat  9 , and when the value of M is positive, the rubber valve seat  8  opens the valve seat  9 . That is, the above-mentioned condition can be satisfied in various ways through appropriate settings of the magnitude of the buoyancy F of the float main body  5 , the strength of the attraction force of the magnet  13 , the self-weight G of the float  200 A, the diameter of the flow path of the valve seat  9 , the compressed air pressure, and the distances X, Y, Z, and K between the rotation shaft  20   a  and the positions where the above-mentioned forces are exerted. That is, the buoyancy F varies depending on the amount of drain water, and the self-weight G of the float  200 A varies depending on the inclination of the arm  20 , which results from the buoyancy. 
         [0042]    In this way, through the provision of the attraction force due to the magnet  13  and through the provision of the plate spring  14 , it is possible for the rubber valve seat  8  to open or close the valve seat  9  instantaneously. Further, it is possible to prevent the valve seat  9  from being placed in a half-open state. 
         [0043]    To constrain the plate spring  14 , there is provided the plate spring bracket  15  as the constraining means, thereby constraining the plate spring  14  so as not to be easily bent upwardly. 
         [0044]    The above description of the present invention should not be construed restrictively. It is also possible for the magnet  13  to be arranged to be connected to the rubber valve seat  8  for opening and closing the valve seat  9  situated in the outlet port  50   b  formed in the case main body  50 , thereby directly contributing to the opening and closing. It is also possible to connect the float main body  5  and the magnet  13  by a chain, a wire, etc., and when the buoyancy is applied to the float main body  5 , the attraction force of the magnet  13  is overcome. Thus, the position of the rubber valve seat  8  is directly shifted, thereby opening the valve seat  9 . In this case, the magnet  13  and the rubber valve seat  8  may be integrated with each other. 
         [0045]    Further, said rubber valve seat  8  is composed of a rubber, however it is able to make said valve seat  8  by a resin, metal and so on.