Pressure regulator valve with boost feature

A transmission control system comprising:

• a main source of pressurized fluid;
• a control source of pressurized fluid;
• a main pressure regulator for establishing the pressure output of said main source of pressurized fluid at a main pressure level;
• said main pressure regulator having first pressure responsive surface area subject to pressurized fluid within said main source, and a second pressure responsive surface area which, when subjected to pressurized fluid within said control source, will limit said main pressure level, and a third pressure responsive surface area which, when supplied with pressurized fluid within said control source, will increase the limit of said main pressure level;
• a sleeve slidably disposed within said main pressure regulator, said sleeve having a first position and a second position;
• and
• said sleeve being operable in said first position to exhaust fluid pressure at said third pressure responsive surface area and being operable in said second position to direct pressurized fluid within said control source to said third pressure surface area to provide an increase in said main pressure level.

A transmission control system comprising:

• a main source of pressurized fluid;
• a control source of pressurized fluid;
• a main pressure regulator for establishing the pressure output of said main source of pressurized fluid at a main pressure level;
• said main pressure regulator having first pressure responsive surface area subject to pressurized fluid within said main source, and a second pressure responsive surface area which, when subjected to pressurized fluid within said control source, will limit said main pressure level, and a third pressure responsive surface area which, when supplied with pressurized fluid within said main source, will decrease the limit of said main pressure level;
• a sleeve slidably disposed within said main pressure regulator, said sleeve having a first position and a second position;
• and
• said sleeve being operable in said second position to exhaust fluid pressure at said third pressure responsive surface area and being operable in said first position to direct pressurized fluid within said main source to said third pressure responsive surface area to provide a decrease in said main pressure level.