System for regulating pressure within and dispensing from a beverage container

A system for regulating pressure within a beverage container, the system comprising a regulator cap having:

• a high-side cartridge assembly comprising:
• a cartridge shell enclosing a high-pressure cavity,
• a piercing tip configured to puncture a pressurized-gas container,
• a high-pressure passage extending through the piercing tip and to the high-pressure cavity, and
• a piston configured to bidirectionally travel within the high-pressure cavity in a direction of travel of the piston and to intermittently open the high-pressure cavity to a low-pressure cavity that is external to the high-side cartridge assembly, the high-pressure cavity configured to operate at a high operating pressure, and the low-pressure cavity configured to operate at a low operating pressure, the high operating pressure being at least thirty times greater than the low operating pressure at normal temperature;
• a low-side cap assembly comprising:
• a cap body having a socket configured to receive the high-side cartridge assembly, no part of the cap body forming a boundary of the high-pressure cavity,
• a spring-loaded actuator within the cap body and in contact with the piston,
• means for adjusting a spring force applied to the actuator in the direction of travel of the piston, and
• a one-way valve configured to permit gas in the low-pressure cavity to pass to a region external to the regulator cap;
• and
• a retainer configured to retain the high-side cartridge assembly within the socket of the cap body, in which the retainer is secured to the cap body by a snap fit, the retainer further comprising a pair of retainer tabs configured to be pinched by a user for removal of the retainer from the cap body.