Variable flow air flow controller

A system for controlling operation of a pneumatic tool that is powered by compressed air, the system comprising:

• an inlet for being connected to a source of compressed air;
• an outlet for communicating an air flow to a pump of a paint delivery system;
• at least two flow paths between the inlet and the outlet;
• and
• an air flow controller constructed to 1) allow flow along a first flow path via operation of a valve when a flow rate at the outlet approximates a desired flow rate as determined by a pressure regulator and a flow meter based on a viscosity of a first fluid passed through the pump and 2) allow flow along a second flow path when the flow rate at the outlet exceeds a threshold associated with the desired flow rate as determined by the pressure regulator and the flow meter and base on a viscosity of a second fluid passed through the pump that has a different viscosity than the first fluid to maintain a desired reciprocation rate of the pump during operation of the pump to move fluids having different viscosities and as a function of the viscosity of fluid delivered by the pump and independent of a static or dynamic nature of the air flow to the pump.

A pneumatic system comprising:

• a tool powered by a flow of compressed air;
• an air flow control valve for providing a desired air flow rate that is to be communicated to the tool powered by the flow of compressed air such that the tool operates at a first cycle rate;
• and
• a controller connected to the air flow control valve and disposed upstream of a pressure based flow meter and configured to:
• 1) allow the air flow to the tool at the desired flow rate along a first flow path associated with the airflow control valve when the air flow is not more than the desired flow rate based on a viscosity of a fluid moved by the tool to achieve the first cycle rate;
• and
• 2) allow the air flow to the tool at another air flow rate associated with a second flow path automatically in response to changes in viscosity of the fluid moved by the tool if the air flow rate exceeds the desired air flow rate to maintain operation of the tool proximate the first cycle rate and wherein the desired air flow rate and the another air flow rate associated with the first and second flow paths are allowed to flow to the tool independent of a static and dynamic nature of the air flow.