Automatic pressure control system

DETAILED DESCRIPTION What is claimed is: 1.
A pressure supply system for supplying adjustable and controlled outlet pressure selectively lower or higher than a gas supply pressure, including in combination a first pressure regulator connected on its upstream side to a supply source for gas under pressure, a port on the downstream side of the first pressure regulator from which gas under controlled and reduced pressure is supplied to the system, a first passage connected with said port of the first regulator for connection with an ultimate delivery outlet, a pressure intentsifier pump connected at an intermediate location along the course of said first passage, an activator for operating the pressure intensifier pump to increase the delivery pressure from said first passage to the ultimate delivery outlet when the pressure necessary at the ultimate delivery outlet is in excess of the delivery pressure of the first regulator, a controller that operates the actuator, a connection between the first regulator and the controller for making the controller responsive to the pressure at the first pressure regulator, a second pressure regulator with an upstream port for connection with a source of intermediate pressure fluid, and means connected with the downstream side of the second pressure regulator for restoring the pressure intensifier pump actuator to position for a successive operation when the actuator has been operated by said controller through a stroke that intensifies the pressure delivered to the ultimate delivery outlet.
2.
The pressure supply system described in claim 1 characterized by connecting means, between the activator and the pressure intensifier pump, that provide a large mechanical advantage for the activator, whereby the activator can operate the pump with the working fluid pressure supplied to the actuator substantially lower than the delivery pressure against which the pump delivers gas to the ultimate delivery outlet.
3.
The pressure supply system described in claim 2 characterized by the activator including a cylinder-and-piston motor, and the pressure intensifier pump being a cylinder-and-piston pump, the cylinder of the activator being of substantially larger diameter than that of the pump to provide a mechanical advantage