Automatically closing control valve for the delivery of liquids

Abstract

An automatically closing control valve for liquids which includes entry ( 3′ ) and exit ( 4′ ) apertures and an internal chamber ( 5 ) in which a piston ( 6 ) that opens and closes the entry ( 3′ ) and exit ( 4′ ) apertures slides. The valve ( 1 ) has springs ( 10, 20 ) that closes the piston ( 6 ), mechanical or pneumatic means ( 11, 22, 23 ) to keep the piston ( 6 ) open and a monitoring probe ( 12, 26 ). The probe ( 12, 26 ) communicates with pneumatic means ( 15, 16, 28, 29 ) that keep the piston ( 6 ) in an opened position and that operate the springs ( 10, 20 ) that returns the piston ( 6 ) upon reaching maximum level. The aperture ( 4′ ) is connected to the nozzle ( 4″ ) shaped as a Venturi tube, which creates the vacuum to activate the pneumatic means ( 15, 28 ).

1 . An automatically closing control valve for the delivery of liquids, particularly for low pressure delivery circuits, including a main casing ( 2 ), an entry aperture ( 3 ′) and an exit aperture ( 4 ′) of the liquid, a main internal chamber ( 5 ) of basically cylindrical shape, in which a piston ( 6 ) slides along the axial direction of said main chamber ( 5 ), said piston defining, with its movement, at least one opening and one closing position of said entry ( 3 ′) and exit apertures ( 4 ′), said valve ( 1 ) also having return elastic means ( 10 ,  20 ) of said piston ( 6 ) towards said closing piston, holding means ( 11 ,  22 ,  23 ) of said piston ( 6 ) in an opening position, monitoring means ( 12 ,  26 ) of a predetermined maximum level of liquid delivered into a container (B) characterised in the said monitoring means ( 12 ,  26 ) are operatively connected to pneumatic actuation means ( 15 ,  16 ,  28 ,  29 ) suitable to interact with said means ( 11 ,  22 ,  23 ) holding said piston ( 6 ) in an opening position to control the activation of said return elastic means ( 10 ,  20 ) to put the same piston ( 6 ) in a closing position upon reaching said predetermined level of liquid delivered.  
     
     
         2 . A valve as in  claim 1 , characterised in that a duct ( 4 ) with a section ( 4 ″), having a section shaped as a Venturi tube, is connected to said exit aperture ( 4 ′), to generate, a vacuum in said pneumatic actuation means ( 15 ,  16 ,  28 ,  29 ) upon the passage of the liquid.  
     
     
         3 . A valve as in  claim 2 , characterised in that said means ( 12 ,  26 ) monitoring the reaching of a predetermined level of liquid delivered into a container (B) include an open duct ( 12 ,  26 ) the lower end of which is suitable to be blocked by said liquid.  
     
     
         4 . A valve as in  claim 3 , characterised in that said means holding the piston ( 6 ) in an opening position are made up of a mechanical leverage ( 23 ,  24 ,  30 ) for locking the same piston ( 6 ), acting on a rod ( 21 ) anchored in an axial position to the piston ( 6 ) itself.  
     
     
         5 . A valve as in  claim 4 , characterised in that said mechanical leverage ( 23 ,  24 ,  30 ) is suitable to be unlocked by the deformation of a first membrane ( 29 ) operated by a vacuum generated in a first pneumatic chamber ( 28 ).  
     
     
         6 . A valve as in  claim 3 , characterised in that said means holding the piston ( 6 ) in an opening position are made up of pneumatic means generating a vacuum in said main chamber ( 5 ).  
     
     
         7 . A valve as in  claim 6 , characterised in that valve means ( 17 ) suitable to open and interrupt communication between said main chamber ( 5 ) and the external surrounds of the valve itself are provided.  
     
     
         8 . A valve as in  claim 7 , characterised in that said valve means ( 17 ) are operated to interrupt said communication by spring means and to open said communication by a second membrane ( 16 ), deformable by the vacuum created in a second pneumatic chamber ( 15 ).  
     
     
         9 . A valve as in one or more of the previous claims, characterised in that said return elastic means of said piston ( 6 ) in a closing position are made up of mechanical springs ( 10 ,  20 ).