Metering valve with improved metering chamber

Abstract

Metering valve for dispensing a fluid product, having a valve body containing a metering chamber, the metering chamber defined by a chamber insert and two O-rings, a valve stem seal and a chamber seal. The chamber insert has a cylindrical wall, an upper edge that cooperates with the valve stem seal and a lower edge that cooperates with the chamber seal, a valve stem sliding axially in the valve body between a rest position and a dispensing position, to selectively dispense the contents of said metering chamber. The said valve stem is urged towards its rest position by a spring that cooperates, on the one hand, with the valve body and on the other hand with the valve stem. The upper edge of the chamber insert has an opening connecting the metering chamber to an external volume arranged outside the chamber insert, between the valve body and 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 O-rings, a valve stem seal and a chamber seal, said chamber insert comprising a cylindrical wall, an upper edge that cooperates with said valve stem seal and a lower edge that cooperates with said chamber seal, a valve stem 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 stem being urged towards its rest position by a spring that cooperates, on the one hand, with said valve body and on the other hand with said valve stem, characterised in that said upper edge of said chamber insert comprises an opening connecting said metering chamber to an external volume arranged outside said chamber insert, between said valve body and said cylindrical wall. 
     
     
         2 . The metering valve according to  claim 1 , wherein said upper edge of said chamber insert extends radially inwards by a upper flange which increases the contact surface with said valve stem seal, said contact surface always being the same, whatever the width of said cylindrical wall. 
     
     
         3 . The metering valve according to  claim 1 , wherein said lower edge of said chamber insert extends radially inwards by a lower 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 . The metering valve according to  claim 1 , wherein the volume of said metering chamber is modifiable between 25 and 100 μl, without modification of said valve body, by adapting the thickness of said cylindrical wall and/or the number, shape and/or dimensions of said openings. 
     
     
         5 . The metering valve according to  claim 1 , wherein said cylindrical wall of said chamber insert comprises a single opening. 
     
     
         6 . The metering valve according to  claim 1 , wherein said cylindrical wall of said chamber insert comprises two diametrically opposed openings.. 
     
     
         7 . The metering valve according to  claim 1 , wherein said cylindrical wall of said chamber insert comprises a plurality of openings distributed over the periphery of said cylindrical wall. 
     
     
         8 . Device-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. 
     
     
         9 . The device according to the  8  claims, wherein said propellant comprises HFA gases, such as HFA a and/or HFA-227 and/or HFA-152a. 
     
     
         10 . The device according to  claim 8 , wherein said propellant comprises HFO1234ze.