Patent Publication Number: US-6669167-B2

Title: Structure of a LPG tank valve

Description:
BACKGROUND OF THE INVENTION 
     (a) Technical Field of the Invention 
     The present invention relates to an improved structure of a LPG tank valve, and in particular, an urging device within the valve of a LPG tank. 
     (b) Description of the Prior Art 
     FIG. 1 is a perspective view of a conventional LPG tank valve and a LPG tank. The valve  20  is connected to a stove  30  via a connection tube (not shown). The bottom end of the valve  20  is provided with a threaded connector  211  for mounting with the threaded head  11  of the LPG tank  10 . The needle valve  12  within the threaded head  11  is in engagement with an urging device  23  within the threaded connector  21 . FIG. 2 is a sectional view showing the valve of LPG tank in a closed position. The bottom end of the rotating button  22  in aligned with the urging device  23  is provided with a press rod  24 , and the urging device  23  comprises a tube body  25  and a needle valve  26 . One end of the tube body  25  is vertically locked to the threaded connector  21 , and the needle valve  26  is mounted at the mouth of the threaded connector  21  to the vale  20  such that one end of the needle valve  26  protruded out of the threaded connector  21  is located below the rod  24 . When the valve  20  is connected to the LPG tank  10 , the tube body  25  forces open the needle valve  12  within the mouth  11  of he tank, at this instance, LPG fills out the space of the tube body  25 . If the rotating button  22  has not been rotated, the press rod  24  will not press the needle valve  26 , the valve  26  blocks LPG from escaping. When LPG is required, as shown in FIG. 3, the rotating button  22  is rotated downward to press down the rod  24  and the needle valve  26  is opened, the LPG via the inner chamber of the LPG valve  20 , from the outlet tube  27  of the valve, flows to the burner  30 . The conventional structure has the following drawbacks: 
     (1) After a period of use of the LPG tank valve, the inlet of the needle valve is accumulated with carbon residue, and dust, and the valve may not be restored to its closed position, and this may cause a LPG leakage or cause explosion to the burner. 
     (2) The needle valve on the LPG tank is not required as leakage from a LPG tank can be detected in the LPG supplier. Therefore, it is a waste of cost in manufacturing and increases the cost of material. Accordingly, it is an object of the present invention to provide an improved structure of a LPG tank valve which mitigates the above drawbacks. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide an improved structure of a LPG tank valve having a threaded connector mounted onto a LPG tank and a rotating button being provided to one end of the threaded connector, and an urging device being provided to the threaded connector, and the bottom end of the rotating button aligned with the urging device being provided with an urging rod, characterized in that the urging device includes a tube body, an urging rod and a spring, and one end of the tube body is vertically locked to the threaded connector, via the connector and the space of the valve, the tube body is provided with the urging rod, and the rod head of the urging rod is higher than the tube body and is protruded into the mouth of the LPG tank valve, and the lower end of the rod head is connected in series with a spring urged the wall of the tube body, and a gap is formed between the rod body of the urging rod and the wall of the tube body and when the valve is mounted onto the tank the bottom end of the tube body does not urge against the needle valve of the tank and only when the rotating button is depressed, the press down pushes the urging rod and the needle valve is forced to pen and the liquefied gas is released. 
     Yet another object of the present invention is to provide an improved structure of a LPG tank valve, wherein the accumulated carbon or dust will not be formed at the needle valve. 
     Other objects, and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a conventional LPG tank valve and a LPG tank. 
     FIG. 2 is a sectional view showing the conventional LPG tank valve prior to the opening of the valve. 
     FIG. 3 is a sectional view showing the conventional LPG tank valve in the course of opening of the valve. 
     FIG. 4 is a sectional view showing the improved structure of the LPG tank valve in accordance with the present invention. 
     FIG. 5 is a sectional view showing the LPG tank valve prior to the opening of the valve in accordance with the present invention. 
     FIG. 6 is a sectional view showing the LPG tank valve in the course of opening of the valve in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 is a perspective view of a conventional LPG tank valve and a LPG tank. FIG. 2 is a sectional view showing the conventional LPG tank valve prior to the opening of the valve. FIG. 3 is a sectional view showing the conventional LPG tank valve in the course of opening of the valve. 
     FIG. 4 is a perspective view showing the LPG tank valve in accordance with the present invention. In accordance with the present invention, the urging device  110  is positioned within the LPG tank valve  100  and comprises a tube body  111 , an urging rod  112  and a spring  115 . One end of the tube body  111  is vertically locked to the threaded connector  101  of the valve  100  and passes through the space  102  of the valve  100 . The urging rod  112  is inserted into the tube body  111  and the rod head  113  of the urging rod  112  is higher than the mouth of the tube body  111  and is protruded into the valve  100 . The bottom end of the rod head  113  connected in series with the spring  115  urges the wall of the tube body  111 , and a gap  114  is formed between the urging rod  112  and the tube body  111 . 
     FIG. 5 is a sectional view showing the LPG tank valve prior to the opening of the valve in accordance with the present invention. When the valve  100  is mounted onto a LPG tank  200 , the bottom end of the tube body  111  does not press onto the needle valve  202  of the mouth  201  of the tank and the spring force of the spring  115  pushes up the urging rod  112 . At this instance, the liquefied gas within the tank  200  is similar to that in a tank without the valve  100 . As the needle valve  202  seals the tank  200  and the liquefied gas will not release from the tank  200 . As shown in FIG. 6, when the gas is to be released, the rotating button  120  of the valve  100  is rotated downward and the button  120  is protruded to the press rod  121  of the valve  100  to push down the rod head  113 , and the spring force of the spring  115  is overcome. This will cause the urging rod  112  to press open the needle valve  202  of the mouth of the tank  201  to release the liquefied gas within the tank  200 . The gas will flow from the gap  114  to the space  102  of the valve  100  via the outlet tube  103  of the valve  100  to the burner  30 . 
     In view of the above, the LPG tank valve  100  does not need to install a conventional needle valve  26  but employs the needle valve  202  at the mouth  201  of the tank to achieve the transporting of liquefied gas and to prevent liquefied leakage. In accordance with the present invention, the reciprocating of the rod body of the urging rod  112  within the tube body  111  will clear away the accumulated carbon or dust at the gap  114  and the gap will not be blocked. 
     While the invention has been described with respect to preferred embodiments, it will be clear to those skilled in the art that modifications and improvements may be made to the invention without departing from the spirit and scope of the invention. Therefore, the invention is not to be limited by the specific illustrative embodiment, but only by the scope of the appended claims.