Self-limiting pump

A pressurization cap for a game ball container comprising:

• (a) an externally threaded collar adapted for positioning around the container to bear against the bottom of the top ring thereof;
• (b) an internally threaded cap adapted to be threaded onto said collar, said cap having a sealing gasket disposed about the inner periphery thereof;
• (c) a cylinder carried by said cap having a one-way outlet valve communicating through said cap;
• (d) a piston disposed within said cylinder for recriprocating, pumping, motion, said piston having a hollow portion in communication with the pump's cylinder, said hollow portion having a vent opening;
• (e) a piston member disposed within said hollow portion, said piston member being moveable by the pressure being developed by the piston during its compression stroke between a first position blocking said vent opening and a second position exposing said vent opening;
• and
• (f) bias means for biasing said piston member towards said first position and for preventing said second position from being reached until a desired pressure is attained in said cylinder whereby the pressure output of said pump is limited to said desired pressure.

A self-limiting air pump comprising:

• (a) a cylinder with one-way outlet valve:
• (b) a piston disposed in said cylinder for reciprocating, pumping, motion, said piston having a hollow portion in communication with said cylinder, said hollow portion having a vent opening;
• (c) a piston member disposed within said hollow portion, said piston member being moveable by the pressure being developed by the piston during its compression stroke between a first position blocking said vent opening and a second position exposing said vent opening;
• and
• (d) bias means for biasing said piston member towards said first position and for preventing said second position from being reached until a desired pressure is attained in said cylinder whereby the pressure output of said pump is limited to said desired pressure.