Pneumatic needle-free injection device

A pneumatic needle-free injection device comprising:

• a tube body having a hollow configuration and including a first connecting end, a second connecting end, and at least one through hole;
• a linking element including a first linking end engaged with the second connecting end of the tube body, a first concave portion formed at said first linking end, a second linking end, and a second concave portion formed at said second linking end;
• a through hole formed between said first and second concave portions;
• a rear section including a third connecting end engaged with the second linking end of the linking element, a first axial hole formed in the rear section and communicating with the second concave portion of the linking element, and a screw hole formed at an end of the rear section in opposing relationship to the third connecting end;
• a solenoid disposed inside the tube body, the solenoid including a coil, a hollow tube formed inside the coil, and an electric wire connected to the coil and passing through the at least one through hole of the tube body;
• a printed circuit board disposed outside the tube body and electrically connected to the electric wire to control operation of the coil;
• an engaging element having two ends with one end thereof fixedly engaging a rear section of the hollow tube, and another end of the engaging element fixedly engaging the first concave portion, and the engaging element having a second axial hole communicating with the through hole of the linking element;
• a movable element disposed inside the hollow tube at a front section thereof and having a third axial hole therein, said movable element being displaceable by a magnetic force from the solenoid;
• a storage device including a cylinder and a cap;
• said cylinder defining a shrunk opening at a front end thereof, said cap covering a rear opening of the cylinder and engaged within the first connecting end of the tube body;
• said cap having a through hole engaged with the front section of the hollow tube;
• a moving rod having a tail end connected to the movable element and a front end formed with an abutting section which has a greater diameter than the shrunk opening, and the moving rod being displaced for controlling opening and closing of the shrunk opening, said abutting section having a stick extending from a front thereof and the stick stretching into the shrunk opening, said tail end having a fourth axial hole communicating with the third axial hole, and a front of the tail end having at least one radial hole;
• a first spring disposed in the second axial hole of the engaging element and the third axial hole of the movable element to provide elasticity for the movable element and the moving rod and thereby displace the abutting section forward to close the shrunk opening and define a pressure room inside the storage device, wherein pressurized air flows through the first axial hole, the second axial hole, the third axial hole, and the fourth axial hole in sequence and then to the pressure room via the at least one radial hole;
• a housing having said tube body, said linking element, said rear section, said solenoid, said printed circuit board, said engaging element, said movable element, said storage device, said moving rod, and said first spring disposed therein, a front end of the shrunk opening being exposed through said housing, and said housing having at least one button on a surface thereof electrically connected to the printed circuit board;
• and
• a pressure delivery tube engaged to the front end of the shrunk opening with a delivery hole therein connecting to the shrunk opening;
• whereby the solenoid controls displacement of the movable element and the abutting section to ensure circulation of the pressurized air in the pressure room for delivery at high speed and under high pressure into the delivery hole via the shrunk opening.