Patent ID: 8302931

Claim:
A finely adjustable firing valve comprising: a first pneumatic valve ( 10 ) that has a first inlet ( 20 ) and a first outlet ( 21 ) connected through a first actuation chamber ( 22 ); said first valve ( 10 ) also comprising a first shutter ( 23 ), adapted to move within said first actuation chamber ( 22 ) in order to alternately put into communication said first inlet ( 20 ) with said first outlet ( 21 ) or said first inlet ( 20 ) with a first connection conduit ( 33 ) in communication within said first actuation chamber ( 22 ); said first shutter includes a hole ( 26 ) which connects said first actuation chamber ( 22 ) with said first inlet ( 20 ); said firing valve further comprising a second pneumatic valve ( 11 ), adapted to command said first valve ( 10 ), comprising a second actuation chamber ( 36 , 38 ), of an inferior volume than the first actuation chamber ( 22 ); said second valve ( 11 ) also comprising a second shutter ( 37 ), adapted to move within said second actuation chamber ( 36 ), to put alternatively in communication said first connection conduit ( 33 ) with a second outlet ( 35 ) or said first connection conduit ( 33 ) with a second connection conduit ( 40 ); said firing valve further comprising a third valve ( 12 ), able to control said second valve ( 11 ) comprising a third actuation chamber ( 42 ), of an inferior volume than the said second actuation chamber ( 36 , 38 ); said third valve ( 12 ) also comprising a third shutter ( 43 ), able to move within said third actuation chamber ( 42 ), in order to alternately put into communication said second connection conduit ( 40 ) with a third connection conduit ( 41 ) or said second connection conduit ( 40 ) with a fourth connection conduit ( 44 ); characterized in that the finely adjustable firing valve comprises: a piston ( 24 ) bound to said first shutter ( 23 ) that slides within said first chamber ( 22 ), of such a size that the upper surface of said piston ( 24 ) affected by the pressure inside said first chamber ( 22 ) is substantially equal to the lower surface of said piston ( 24 ) affected by the pressure present in said first inlet ( 20 ); a fourth chamber ( 30 ) connected to a fifth connection conduit ( 34 ), said fourth chamber ( 30 ) being of variable volume due to the movement of the piston ( 24 ).