Patent ID: 7293574

Claim:
A pressure reducing regulator that has a central axis and is threadable to a cylinder neck portion which has a top annular edge, comprising a main body having a lower annular chamber that at least in part is defined by a top annular wall, a radial outer annular portion extending axially below the annular wall, surrounding the top annular wall and being internally threaded and a radial centered reduced diameter portion extending to a lower elevation than the annular portion, and a main body top portion; the main body having a bore extending axially therethrough, including through the body reduced diameter portion and through the main body top portion, the main body bore having a top bore portion and a lower bore portion having a part providing an inlet and a part of a smaller diameter than the top bore portion and opening thereto to provide a valve seat, a cap having an outlet and connected to the main body top portion to in conjunction therewith provide a control chamber that at least in part is defined by an internal wall surface portion and includes a control chamber top portion opening to the outlet, and a piston axially movable in the control chamber and having a piston head in fluid sealing relationship with the wall surface portion, the piston having an fluid passage that opens through the piston head to the control chamber top portion and to the valve seat, the piston being movable in the control chamber between an open position permitting fluid flow through the valve seat from the inlet to the outlet when the fluid pressure at the outlet falls below a preselected level and a closed position that at least one of the piston and an insert mounted to the piston abuts against the valve seat to block fluid flow to the piston passageway when the pressure at the outlet is at least a preselected valve and means for resiliently urging the piston to its open position when the pressure at the outlet falls below the preselected level.