Device for dispensing a fluid product comprising a metering valve
Device for dispensing a fluid product, having a reservoir containing the fluid product and a metering valve having a valve body containing a metering chamber, a valve shut-off element sliding axially in the valve body between an rest position and a dispensing position in order to dispense the contents of the metering chamber. The valve shut-off element is urged towards its rest position by a valve spring, the reservoir containing a follower-piston and a piston spring that axially urges the follower-piston towards the metering valve, the follower-piston being suitable for axially sliding in the reservoir in a sealed manner after each actuation to compensate for the volume of each dispensed dose.
1 . A device for dispensing a fluid product, comprising a reservoir containing the fluid product and a metering valve comprising a valve body containing a metering chamber, a valve shut-off element sliding axially in said valve body between a rest position and a dispensing position, in order to dispense the contents of said metering chamber, said valve shut-off element being urged towards the rest position by a valve spring, said fluid product comprising a liquid formulation made up of one or more active principle in suspension and/or in solution in a liquefied propellant, said reservoir containing a follower-piston which separates said reservoir between an upper reservoir part connected to said metering valve and a lower reservoir part isolated from said metering valve by said follower-piston, wherein said reservoir contains a piston spring which axially urges said follower-piston towards said metering valve, said follower-piston being adapted for axially sliding in said reservoir in a sealed manner after each actuation, in order to compensate for a volume of each dose dispensed, said follower piston being pushed axially downwards by said fluid product when filled in said reservoir, such that said follower-piston compresses said piston spring and air arranged in said reservoir lower part until the pressures are balanced between said upper part of the reservoir containing said fluid product in liquid form and said lower part of the reservoir containing the air and said compressed piston spring; and
wherein the fluid product is pressurized by the propellant.
2 . The device according to claim 1 , wherein, after each actuation, said piston spring pushes said follower piston axially upwards to compensate for a decrease in volume generated by the dispensing of a dose of fluid product, without substantial modification of the pressure in said upper part of the reservoir, such that said fluid product always remains in liquid form.
3 . The device according to claim 1 , wherein said piston spring exerts a pressure adapted to compensate for each decrease in volume after each actuation, but without exerting a pressure on said follower piston that is liable to hinder the filling of said reservoir with said fluid product.
4 . The device according to claim 1 , wherein said propellant comprises HFA gas.
5 . The device according to claim 1 , wherein said propellant comprises HFO1234ze.
6 . The device according to claim 1 , wherein said propellant comprises one or more of HFA 134a, HFA 227, and HFA-152a.
7 . A device for dispensing a fluid product, comprising:
a reservoir containing the fluid product and a metering valve comprising a valve body containing a metering chamber, a valve shut-off element sliding axially in said valve body between a rest position and a dispensing position, in order to dispense the contents of said metering chamber, said valve shut-off element being urged towards the rest position by a valve spring, said fluid product comprising a liquid formulation made up of one or more active principle in suspension and/or in solution in a liquefied propellant, said reservoir containing a follower-piston which separates said reservoir between an upper reservoir part connected to said metering valve and a lower reservoir part isolated from said metering valve by said follower-piston, wherein said reservoir contains a piston spring which axially urges said follower-piston towards said metering valve, said follower-piston being adapted for axially sliding in said reservoir in a sealed manner after each actuation, in order to compensate for a volume of each dose dispensed, said follower piston being pushed axially downwards by said fluid product when filled in said reservoir, such that said follower-piston compresses said piston spring and air arranged in said reservoir lower part until the pressures are balanced between said upper part of the reservoir containing said fluid product in liquid form and said lower part of the reservoir containing the air and said compressed piston spring; and
wherein the fluid product is pressurized by the propellant, the propellant provided in the fluid reservoir.