A ball check poppet valve  opens when spring pressure pushes the piston up. This allows air from the supply line to enter above the piston forcing it down and closing the poppet valve. A pressure regulator adjusts the speed of the needle running @ about 10-20 lbs pressure and 50-100 strokes per minute. This speed regulation allows an artist to draw longer and more continuous lines. With the ink pumped thru micro tubing to the needle bar can also allow the artist the convenience of not having to dip for ink.

copyright 2006 pat. pending.