Pressure tank
STATEMENT OF GOVERNMENT INTEREST 
     The invention described herein may be maufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to a pressure tank for use in providing a pressurized gas source where needed and, more particularly, the invention is concerned with providing a tank source of pressurized gas produced by discharging a cartridge in a chamber and directing the gases to the interior of the tank. 
     Heretofore, it has been common to pressurize storage tanks by attaching to compressors or carbon dioxide cartridges and filling the tanks to the desired pressure. Other systems utilize hot combustion gases in combination with liquified carbon dioxide or other refrigerants to produce gas to fill inflatable devices such as boats, rafts, rescue devices, etc. These systems have certain obvious drawbacks including the requirement of a power source to operate the compressor and/or a supply of carbon dioxide cartridges. It can be seen that these requirements necessarily limit the portability of any inflatable device which is in the deflated state. Thus it should be noted that it would be most desirable to provide a gas pressure source which does not require a cumbersome gas generator with the accompanying chemical supply nor require an electrical or gasoline powered compressor. The hereinafter described pressure tank does provide a pressurized gas source without the above-mentioned disadvantages. 
     SUMMARY OF THE INVENTION 
     The present invention provides an improved pressurized storage tank compressed gas source for use with an air pressure gun or the like and is characterized by a chamber in the base of the tank for holding a cartridge which contains combustible gas producing material. When the cartridge is discharged, the chamber is pressurized and the gases therein flow through a check valve into the main tank. The process is repeated until the pressure in the main tank reaches the desired level. 
     Accordingly, it is an object of the present invention to provide a pressure storage tank suitable for storing gas under pressure which can be used for inflating flotation devices or any of numerous circumstances where pressurization is needed on demand. 
     Another object of the invention is to provide a means for producing a pressurized gas including apparatus which is light in weight and completely portable. 
     Still another object of the invention is to provide a pressure tank which is simple and economical in construction of readily available material and parts while being safe and reliable in operation. 
     These and other objects, features and advantages will become more apparent after considering the following description taken in conjunction with the annexed drawings and appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The FIGURE is a side view in partial section of a pressure tank according to the invention showing the details of the cartridge, pressure chamber and firing mechanism in idealized form. 
    
    
     DESCRIPTION OF A PREFERRED EMBODIMENT 
     Referring to the drawing in detail, the FIGURE depicts a main pressure tank 13 having an interior 15 and side wall 17. The tank 13 is provided with a base 19 which also forms the base of a chamber 21 located at the rearward end of the tank 13. A curved, preferably hemispherical, wall 23 forms the forward wall of the chamber 21 and extends into the interior of the tank 13. A check valve 25 is fixedly positioned in the curved wall 23 of the chamber 21 to allow gases therein to flow into the interior 15 of the tank 13 and to prevent gases in the interior 15 of the tank 13 from flowing back into the chamber 21. 
     Through the center of the base 19 there is positioned a receptacle 27 for receiving a charging cartridge 29 having its forward end in operative communication with the interior of the chamber 21. The rearward end of the cartridge 29 extends back outside the receptacle 27 leaving the primer affixed thereto exposed. A closure cap 31 having a firing pin 33 slidably positioned in the center thereof closes off the outer end of the receptacle 27 and effectively retains the cartridge 29 in position therein. The firing pin 33 is in alignment with the primer in the cartridge 29 so that a blow from the firing pin 33 will cause the primer of the cartridge 29 to explode. 
     A spring loaded striker 35 is pivotably attached to the base 19 of the tank 13 by means of the spring biased pivot member 37 which urges the striker 35 to move clockwise. A striker latch 39 holds the striker 35 under load after being pulled back by the handle 41 to the loaded position. The cartridge 29 can now be fired by releasing the striker 35. A safety pressure release valve 43 which may be in the form of a blowout plug is installed in the base 19 of the tank 13 to prevent overpressurization with the resultant dangers of bursting. 
     A master control valve 45 is operatively connected to the forward wall of the main storage tank 13 for controlling the flow of pressurized gas from the interior 15 of the tank 13. A tank pressure gauge 47 is attached to the line 49 to indicate the pressure in the interior 15 of the main tank 13 and a pressure regulating valve 51 along with a gauge 53 to indicate the outlet pressure is attached in the tank outlet line 55. 
     In operation, to pressurize the main tank 13, close the master control valve 45 thereby effectively sealing the interior 15 of the main tank 13. Pull back on the spring loaded striker 35 by grasping the handle 41 and moving counterclockwise until the latch 39 attaches to the striker 35 and holds it fast against the force exerted by the spring biased pivot member 37 which urges the striker 35 to move clockwise. Remove the closure cap 31 and install a charging cartridge 29 in the receptacle 27. Replace the closure cap 31 over the base of the installed charging cartridge 29. While holding the striker 35 with one hand by means of the handle 41, unhook the striker latch 39, then release the striker 35 which strikes the firing pin 33 in the closure cap 31. This causes the primer in the base of the charging cartridge 29 to explode and cause the charge to fire. After the cartridge 29 is fired the chamber 21 is filled with gas pressure which then passes through the check valve 25 to the interior 15 of the tank 13 causing the tank to pressurize. 
     By opening the master control valve 45 while the pressure regulating valve 51 is closed, the tank pressure gauge 47 will give an indication of the pressure inside the tank 13. If the pressure is not high enough for the uses desired, the master control valve 45 can be closed and the process repeated, that is, another cartridge 29 can be fired until the desired pressure is obtained. 
     From the foregoing description, it can be seen that there is disclosed an improved, relatively simple, light-weight and versatile apparatus which is suitable for producing a pressurized gas for air pressure guns or other purposes where an auxiliary source of pressure is required. The apparatus functions equally well at all extremes of temperature as well as at any altitude. 
     Although the invention has been illustrated in the accompanying drawing and described in the foregoing specification in terms of a preferred embodiment thereof, the invention is not limited to this embodiment or to the particular configuration mentioned. It will be apparent to those skilled in the art that my invention could have extensive use in other operations where it is desirable to provide a pressure source for inflating rafts, vehicle tires, and other inflatable devices used by the armed forces especially in the field where electrical power and gasoline generators may be unavailable. Also, it should be noted that certain changes, modifications and substitutions can be made, particularly with respect to the positioning of the various valves and gauges without departing from the true spirit and scope of the appended claims.