Aerosol apparatus for inhalation therapy

Claim 1

In an aerosol apparatus for inhalation therapy comprising a casing forming a chamber, said casing forming an axially extending inlet orifice arranged to communicate with the interior of the chamber and with the atmosphere about said casing, an outlet spaced from and in approximate axial alignment with said inlet and a wall structure disposed within said chamber and located between said inlet orifice and said outlet, spray jet means arranged to discharge therefrom a conical liquid spray, a container for liquid, and liquid propelling means arranged for selectively causing a liquid in said chamber to be propelled to said spray jet means to be discharged therefrom in the form of a spray, the improvement which is characterized by said inlet orifice having a first end adjacent the outer surface of said casing and a second end within said chamber, the axially extending inner surface of said inlet orifice comprising a first annular surface extending in the axial direction of said orifice from the first end thereof with said first surface converging toward the axis of said inlet orifice toward said second end and a second annular surface extending from said first surface to said second end with said second surface diverging from the axis of said inlet orifice from said first surface to said second end thereof and said first and second surfaces providing a Venturi effect on gases passing therethrough, the axis of said jet means being in substantial alignment with the axis of said inlet orifice and the outlet from said spray jet means being located in said inlet orifice in the range of said first surface thereof for passage of said spray through said inlet orifice into said chamber for contacting said wall structure of said casing and the periphery of said conical liquid spray being contiguous with respect to said inner surface of said inlet orifice so that air is propelled therethrough by the action of said spray with enhanced velocity as it passes through said inlet orifice, baffle means positioned within said chamber and being in the form of a cone disposed with its axis in substantial alignment with the axis of said inlet orifice and the axis of said conical spray emitted from said spray jet means, the small end of said cone being arranged facing toward said inlet orifice in proximate spaced relation therewith and being rounded affording a convexly shaped surface directed toward said inlet orifice, the frustoconical sidewall of said cone extending from its rounded small end being substantially aligned with respect to the periphery of the conical spray emitted from said spray jet means and said cone being hollow and open at its larger end which is arranged in proximate spaced relation to said outlet, the interior surface of said wall structure of said casing comprises a portion which is in surrounding spaced juxtaposed relation to the external surface of said cone and said portion is concave with the maximum spacing between said concave portion and the external surface of said cone being in opposed relation to an intermediate portion of said cone between its rounded small end and open larger end such that a secondary Venturi is provided in the space between the interior surface of said casing and said cone in the region where the spray from said spray jet means impinges on said cone adjacent its smaller end.