Seal for an inhalation device
The invention relates to the field of inhalation devices for liquids. In particular, the invention relates to an improved seal construction for an inhalation device having a nebulizing nozzle and a piston which moves relative to a pumping chamber in order to generate pumping pressure and to an inhalation device comprising such seal.
1. An inhalation device for medically active liquids for generation of an aerosol, comprising:
a housing;
an impingement nozzle for generating the nebulised aerosol by collision of at least two liquid jets, the nozzle being firmly affixed to a user-facing side of the housing so as to be immobile relative to the housing;
inside the housing the inhalation device comprises:
a reservoir for storing a liquid;
a pumping device with:
a pumping chamber for generation of a pressure inside said pumping chamber which is moveable relative to the housing or to the nozzle, wherein the pumping chamber is fluidically connected with the reservoir;
a riser pipe which can be received with at least one reservoir-facing, interior end in said pumping chamber, and said nozzle which is connected liquid-tight to an exterior end of the riser pipe that is immobile and firmly attached to the housing or to the nozzle, wherein the interior volume of the pumping chamber is changeable by means of relative motion of the pumping chamber to the riser pipe, wherein the pumping chamber is pushed onto the immobile riser pipe to increase the pressure and press the medically active liquid out of the nozzle;
characterized in that a gap is present between an outside of said riser pipe and an inside of said pumping chamber, the gap being bridged by a seal for minimizing pressure loss when a pressure is generated inside said pumping chamber.
2. The inhalation device according to claim 1 , wherein said seal is fixed to said outside of said riser pipe.
3. The inhalation device according to claim 2 , wherein said outside of said riser pipe exhibits a higher surface roughness than said inside of said pumping chamber.
4. The inhalation device according to claim 3 , wherein said riser pipe exhibits a constricted region or an expanded region.
5. The inhalation device according to claim 2 , wherein said riser pipe exhibits a constricted region or an expanded region.
6. The inhalation device according to claim 1 , wherein said seal is being fixed to said inside of said pumping chamber and moveable with respect to said outside of said riser pipe.
7. The inhalation device according to claim 6 , wherein said outside of said riser pipe exhibits a lower surface roughness than said inside of said pumping chamber.
8. The inhalation device according to claim 7 , wherein said inside of said pumping chamber exhibits a recess or a rim.
9. The inhalation device according to claim 6 , wherein said inside of said pumping chamber exhibits a recess or a rim.
10. The inhalation device according to claim 1 , wherein said seal is an O-ring, a flat ring, a piston ring, or a tube.
11. The inhalation device according to claim 1 , wherein said seal is made of an elastomer, Polytetrafluoroethylene, or a metal.
12. The inhalation device according to claim 1 , wherein the inhalation device comprises at least two of said seals, being arranged serially.
13. The inhalation device according to claim 12 , wherein at least two of said seals are spaced apart so as to prevent a tilting of the riser pipe in the pumping chamber.
14. The inhalation device according to claim 1 , wherein the generation of the aerosol occurs without a propellant.