Metering valve having an improved metering chamber

Abstract

Metering valve for dispensing a fluid product, having a valve body containing a metering chamber defined by a chamber insert and two annular seals, a valve seal and a chamber seal. The chamber insert has a cylindrical wall, an upper edge cooperating with the valve seal and a lower edge that cooperates with the chamber seal. A valve slides axially in the valve body between a rest position and a dispensing position, so as to selectively dispense the contents of the metering chamber, the valve being urged towards its rest position by a spring that cooperates with the valve body and with the valve. The upper edge of the chamber insert has an annular cutout formed on the radially inner side of the upper edge, so that the width of the upper edge in contact with the valve seal is always the same, whatever the width of the cylindrical wall.

1 . A metering valve for dispensing a fluid product, comprising a valve body containing a metering chamber, said metering chamber being defined by a chamber insert and two annular seals, a valve seal and a chamber seal, said chamber insert comprising a cylindrical wall, an upper edge cooperating with said valve seal and a lower edge cooperating with said chamber seal, a valve sliding axially in said valve body between a rest position and a dispensing position, to selectively dispense the contents of said metering chamber, said valve being urged towards its rest position by a spring cooperating on the one hand with said valve body and on the other hand with said valve, characterised in that said upper edge of said chamber insert comprises an annular cutout formed on the radially inner side of said upper edge, in such a way that the width of said upper edge in contact with said valve seal is always the same, whatever the width of said cylindrical wall; and
 wherein said metering chamber has a variable volume, in particular of between 25 and 75 μl, defined by the radial width of said cylindrical wall.   
     
     
         2 . The metering valve according to  claim 1 , wherein said annular cutout is of rectangular shape in transverse cross section. 
     
     
         3 . The metering valve according to  claim 1 , wherein said lower edge of said chamber insert extends radially inwards by a flange which increases the contact surface with said chamber seal, said contact surface always being the same, whatever the width of said cylindrical wall. 
     
     
         4 . (canceled) 
     
     
         5 . The metering valve according to  claim 1 , wherein the metering chamber has a volume of 50p. 
     
     
         6 . The metering valve according to  claim 1 , wherein the metering chamber has a volume of 28 μl. 
     
     
         7 . The metering valve according to  claim 1 , wherein the axial dimension of said annular cutout is less than 15%, advantageously less than 10%, of the axial dimension of said cylindrical wall. 
     
     
         8 . (canceled) 
     
     
         9 . A device for dispensing a fluid product, characterised in that it comprises a metering valve according to  claim 1 , said valve being mounted on a reservoir containing the fluid product and a propellant. 
     
     
         10 . The device according to  claim 9 , wherein said propellant comprises HFA 152a and/or HFO1234ze.