Automatic choke

An automatic choke comprising:

• a housing defining a central chamber with an inlet opening on a first end and an outlet opening on an opposite second end;
• a first piston cylinder assembly received in said chamber generally aligned with said inlet, the cylinder of said assembly having an open first end and a closed second end which with said piston defines a variable volume chamber, spring means in said variable volume chamber biasing said piston towards said first end;
• a second piston cylinder assembly generally aligned with said outlet, the cylinder of said assembly having a closed end which with said piston defines a variable volume chamber, and a valve member carried by said piston and extending from the other end of said cylinder;
• cylinder means generally aligned with said outlet and having a valve seat in the end opposite said outlet, said second piston-cylinder assembly mounted in said cylinder means so that said valve member interacts with said valve seat;
• and
• conduit means placing said variable volume chambers of said first and second piston-cylinder assemblies in fluid communication whereby movement of said first piston in response to pressure causes a counter movement of said second piston thereby controlling the positioning of said valve and flow through said choke.