A inflation tube includes an inflation bar with its front end closed by a circular disc and its rear end formed into an inwardly extending edge; a gas-spraying head; a movable tube disposed inside the inflation bar and covered with a spring; a small piston connected with the movable tube at the front end of the latter and provided with a central hole. The rear end of the moveable tube extends out of the inflation bar and is connected with the gas-spraying head. The movable tube can stretch out under the pressure of the gas when inflated and draws back due the action of the spring when uninflated.
