Patent ID: 8763596

Claim:
A cartridge for launching a bullet, including a shell case, a pressure chamber and a push rod, wherein, the shell case comprises a shell case front part and a shell case back part, and centers of the shell case front part and the shell case back part define concentric through-holes; wherein a firing chamber for receiving the bullet is defined at an end of shell case front part away from the shell case back part and communicates with the through-holes; wherein the pressure chamber is set up between the through-holes of the shell case front part and the shell case back part; wherein the push rod passes through the pressure chamber; wherein the push rod defines an air vent and an airway, the air vent being in fluid communication with the firing chamber via the airway; wherein a piston is mounted to the push rod and is received in the pressure chamber for compressing air in the pressure chamber; when the cartridge is uncompressed, the air vent is located in the pressure chamber, and the piston is between the air vent and the firing chamber; when air is compressed into the cardtridge, the push rod slides away from the firing chamber, pushing the air vent out of the pressure chamber, and the piston compresses air in the pressure chamber; when an end of the push rod away from the firing chamber is struck to make the air vent move forwards, back into the pressure chamber, the compressed air in the pressure chamber is discharged via the air vent and the airway to fire the bullet received in the firing chamber; and wherein the piston is slidably received in the pressure chamber, and divides the pressure chamber into two sealed spaces.