Patent attributes
A pneumatic pusher having a main body, a flow-guiding body, a moving body, and a delivery tube. The flow-guiding body includes a front tube with a smaller diameter and a rear tube with a larger diameter. The delivery tube is mounted on the front tube in such a way that the outer wall of the delivery tube and the inner wall of the main body define a return pressure chamber. A first gas-distributing channel extending from a first air outlet at one side of the main body leads directly to the inner side of the delivery tube. The side of the first air inlet of the main body communicates with a second gas-distributing channel. The second gas-distributing channel includes an exit located at one side of the return pressure chamber of the delivery tube. The air pressure provided through the second gas-distributing channel serves as cushioning force in pushing the delivery tube outwardly. When the moving plunger blocks the gas distributing chamber in such a way that the gas is stopped to be injected through the first gas distributing channel into the pushing chamber for bringing the delivery tube forward, the gas pressure injected through the second gas distributing channel into the return pressure chamber acts as inward return force for the delivery tube. Therefore, the reciprocating movement of the delivery tube on the front tube can be completely done by the airflow.