Safety controlled valve for gas controller
This application is a continuation, of application Ser. No. 343,700, filed Jan. 28, 1982, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to improvements in gas controllers, provided with a safety controlled valve device at the inlet side of the conventional gas controller to close automatically the gas inlet upon an overflow demand at the gas outlet. A push button device is provided in the controlled valve with an associated push stem to open the ball valve. 
     2. Description of the Prior Art 
     Conventional gas controllers, as widely known, usually use a safety valve or timer to control gas leakage or cut off the gas source when necessary. Many of these are not reliable and when the safety valve or timer system breakdown the controller may be damaged. 
     In view of the above-mentioned defects in conventional gas controllers, the applicant discloses below the improvements in a gas safety controlled device which comprise the instant invention. 
     OBJECT OF THE INVENTION 
     One object of the present invention is to provide an automatic ball valve to close the gas inlet when the gas controller is subject to overloads which could result in cracking or corrosion if the gas flows out too rapidly from the gas tank. 
     Another object of the invention is to provide a safety valve which is urged automatically to close the gas inlet if the gas conduit or a joint should crack or be damaged. 
     Yet another object of the invention is to urge automatically a ball valve to close the gas inlet to avoid accident. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will now be described in greater specificity with reference to the accompanying drawings in which: 
     FIG. 1 is a cross-sectional view of the present invention as attached with a gas controller and the ball valve in the closed position; and 
     FIG. 2 is an enlarged partial cross-sectional view of the present invention with the ball valve in the open position. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in the drawings, the present invention comprises a hollow cover button 1, push stem 2, and fixed body 4. 
     Noting FIG. 2, the cover button 1 has an inwardly directed post 12 spaced from the inner wall forming an annular recess 13 for insertion thereinto of coil spring 3, said post 12 having an internal thread 14 which engages external thread 21 on the upper end of the push stem 2. A control portion of stem 2 has a smaller diameter than the lower portion, and smaller diameter portion allows the insertion of the seal ring 5 between it and the upper end of the recess 42 of the fixed body 4 in order to prevent gas leakage, the seal ring having a slightly larger diameter than the recess. 
     The fixed body 4 is provided in the top and bottom portion with cavity 41, 42 respectively, for insertion thereinto of coil spring 3, the lower end of push stem 2, and seal ring 5. Furthermore, said fixed body 4 has an external thread 43 at the peripheral surface of the bottom portion engageable with an internal threaded bore in the gas controller 10. 
     In the flow channel of gas inlet 11 (i.e. high pressure side) is inserted a ball valve 7 and coil spring 9 to limit the movement of the ball valve 7 upstream. A seal ring 6 is provided in the flow channel downstream of the ball valve 7 to function as a valve seat for ball 7 to prevent gas leakage through the gas controller 10 when the ball valve 7 is in the closed position. The seal ring defines an opening in the flow channel of the gas inlet a predetermined distance above the inner surface of the flow channel are shown in FIG. 2, thereby requiring an effort on the part of the ball member to seat itself in the opening. 
     In normal flow condition, as shown in FIG. 2, the ball valve 7 will be open by means of its gravity weight. However, when the gas outlet side has a demand for excess gas flow (i.e. more than design flow or leakage), the gas from the tank will flow out rapidly through the inlet side 11 resulting in urging the ball valve 7 by flow velocity to move forwardly into the seal ring 6 and holding the ball valve 7 in closed position. If it is desired to open the ball valve, depressing cover button 1 will move the push stem 2 downwardly to engage and urge the ball valve 7 into the open position. Coil spring 3 will return the cover button 1 and associated push stem 2 to the raised position upon release.