Pressurizing and controlling fluid flow to a sealed article

摘要

A needle attached to a valve construction is employed to cut a core from the wall of a tennis ball. A bore in the needle tip receives the core and carries it into the interior of the ball as the needle is inserted until an orifice in the side of the needle is within the ball. Gas is released from an aerosol container into a chamber within the valve construction and then into the ball through the needle orifice. A piston is disposed in the chamber and a helical spring exerts a bias force on the piston normally urging the piston toward the needle and permitting gas flow to the needle. When the pressure within the ball reaches a preselected level the piston moves away from the needle and activates a valve which shuts off the flow of gas. An indicator button external to the valve housing moves with the piston to indicate that the preselected pressure has been reached. The needle is then withdrawn from the ball leaving the core to reseal the hole.