Patent Publication Number: US-2005121087-A1

Title: Three-way valve

Description:
FIELD OF THE INVENTION  
      This invention relates to a three-way valve, particularly to one having a high pressure-enduring force and preventing leakage sufficiently.  
     BACKGROUND OF THE INVENTION  
      A first conventional three-way valve shown in  FIG. 1  includes a body  10  formed integral, a chamber  100  formed in the body  10 , and two O-shaped rings  101 ,  102  located in the chamber  100  matching to a valve  11  so as to have highly effective function of leakage prevention during it is closed up.  
      The valve  11  is shaped spherical, having a lateral through hole  110  possible to be aligned with two outlets  1013 ,  104  to become open for liquid to flow out.  
      Next, a shaft  12  is provided to connect with an upper end of the valve  11 , and a grip  13  is laterally connected with an upper end of the shaft  12  so that rotation of the grip  13  may effect opening and closing of the three-way valve.  
      After the valve  11  is assembled in the chamber  110 , a sleeve  14  is provided to combine with one side of the body  10 , which is further provided with male threads  105  to engage with male threads  140  of the sleeve  14 , preventing leaking from the engaging position of the sleeve  14  combined with the body  10  by means of an O-shaped ring  141  fitting around an inner end of the sleeve  14 . However, the engagement of the male threads  140  and the female threads  105  may cause incomplete tight closeness for the three-way valve. Further, in injecting forming process of the body  10  and the sleeve  14 , the female threads  105  and the male threads  140  may liable to extend outward so that the engaging portion of the sleeve  14  with the body  10  may easily cause leakage, even through the O-shaped ring should be used. Further the error of the male threads  141  and the female threads  105  may also give rise to large friction between the O-shaped ring  101  and the valve  11 , so the valve  11  may be too tight to rotate to cause uneasiness in opening and closing. Or a large force is necessary to open and close the three-way valve.  
      A second conventional three-way valve shown in  FIG. 2  has almost the same structure except that the valve is only a quarter of a sphere instead of the complete sphere of the valve  11  in the first conventional one. Then the second three-way valve has the same male threads  21  in the body  20 , and the sleeve  22  also has female threads to engage with the male threads  21 . Therefore the second conventional three-way valve also has the same disadvantage as the first conventional one.  
     SUMMARY OF THE INVENTION  
      This invention has been devised to offer a three-way valve having a more simple structure than the conventional ones described above, smooth in closing and opening, and preventive for leakage.  
      The feature of the invention is a valve and shaft assembled with each other in advance, and then the assembled unit is placed in a mold used for forming a body and positioned in a chamber of the body after the body is formed by injecting forming process. So the three-way valve in the invention has a simpler structure than the conventional ones described above, and possible to prevent leakage sufficiently. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
      This invention will be better understood by referring to the accompanying drawings, wherein:  
       FIG. 1  is a cross-sectional view of a first conventional three-way valve;  
       FIG. 2  is a perspective view of a second conventional three-way valve;  
       FIG. 3  is a side view of a first embodiment of a three-way valve in the present invention;  
       FIG. 4  is a cross-sectional view of the line A-A in  FIG. 3 ;  
       FIG. 5  is a perspective view of a second embodiment of a three-way valve in the present invention;  
       FIG. 6  is an upper view of the second embodiment of a three-way valve in the present invention; and,  
       FIG. 7  is a cross-sectional view of the second embodiment of a three-way valve in the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      A first preferred embodiment of a three-way valve in the present invention, as shown in  FIGS. 3 and 4 , includes a body  3 , three passageways  30 ,  31 ,  32  formed integral in the body  3 , a chamber  33  formed integral in the body  3 , a plurality of O-shaped rings  34  fixed in the chamber  34  and respectively facing the three passageways  30 ,  31 ,  32 , and a valve  35  to close completely the three passageways  30 ,  31 ,  32  with coordination of the three O-shaped rings  34 .  
      The valve  35  is positioned in the chamber  33 , having a spherical shape and a plurality of through holes  350  for flowing of liquid through any of the three passageways  30 ,  31 ,  32 , and a shaft  351  formed integral with the valve  35 , and a plurality of O-shaped rings  3  fitting around the shaft  351  with spaced-apart distance for preventing liquid from leaking the gap between the shaft  351  and a shaft hole of the body  10 . Further, a grip  36  is provided at an outside of the body to combine laterally with an upper end of the shaft  351  so the grip  36  can rotate the valve  35  to open or close the passageways  30 ,  31 ,  32 .  
      Next, before forming the body  10  by injecting process, the valve  35  is to be placed in advance in a mold used for forming the body  10  so that the valve  35  may be positioned in the chamber  33  after the body  10  has been formed, simplifying the manufacturing process of the three-way valve in the invention. In addition, the pressure-enduring property is also upgraded for the three-way valve.  
      A merit of the invention is that the valve is formed to position in the body at the same time in injecting forming the body, simplifying the manufacturing process for the three-way valve, and upgrading pressure-enduring characteristic and leak-prevention function and convenient handling as well.  
      While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention.