Inhaler

The invention relates to an inhaler for the repeated inhalation of pulverulent pharmaceuticals.

Inhalation appliances of the said type are known. Disadvantages of these appliances are their complicated mechanical construction and the tendency to form conglomerates, as a consequence of air humidity, which can penetrate into their channel system. The invention aims to provide a remedy for these problems.

The invention achieves the object by means of an inhaler having the features of the claim 1.

The whirling-up of the pharmaceuticals in the blow-out channel can be further improved by drilled holes extending radially in the mouthpiece and by a nebulizing device in the blow-out channel. The pharmaceutical supply can be checked through a viewing window in the supply chamber.

As well as practical handling, the inhaler permits optimal dosing accuracy. It can be adjusted to the dosing requirements by the simple exchange of the dosing wheel. It does not require maintenance and can be easily cleaned.

The invention will best be understood from the following detailed description when studied with the accompanying FIGURE which shows a longitudinal sectional view of an inhaler of the invention.

An embodiment example of the invention is portrayed in the FIGURE and is described in more detail below:

The housing (13) has an intermediate floor (21) and is closed with a lid (17) and a baseplate (14). A rotatable cap (4) is supported on the lid (17) via a spring (12), the edge of which cap encloses the upper edge of the housing wall. The rotatable cap (4) has an axially arranged cylinder (7) which projects through the lid (17), the intermediate floor (21) and a frame (20) into the housing (13). The cylinder (7) is, at the same time, the drive shaft for a dosing wheel (1) which has dosing chambers (22) and which is arranged in the housing (13) concentrically relative to the cylinder (7) and between intermediate floor (21) and frame (20). The housing (13) has a supply chamber (2) for the pharmaceutical which, for its part, can be contained in a cartridge. The supply chamber is provided with a viewing window (3) and has an opening (23) whose cross-section corresponds to that of the dosing chamber (22). The baseplate (14) is provided with a mouthpiece (9) which extends radially and contains a blow-out channel (6) with valve (8). The blow-out channel (6) can be closed at one end with a cap (15) and opens out by the other end into a tubular piston (16) which extends into the cylinder (7), starting from the baseplate (14). The blow-out channel (6) is connected for flow with the inner space of the cylinder (7) via an opening (24) and valve (8). The frame (20) has a shaft (5) which connects the dosing chambers (22) with the blow-out channel (6) via a corresponding opening (25) in the mouthpiece (9). The mouthpiece (9) can be provided with drilled holes (10) which run radially and which open out into the blow-out channel (6). The blow-out channel (6) can have a nebulizing device (sieve plate) (11). The pharmaceutical falls through opening (23) out of the supply chamber (2) into the dosing chamber (22) of the dosing wheel (1). By means of rotating the rotatable cap (4), the metered quantity of powder is transported to the discharge shaft (5), and falls through this via opening (25) into the blow-out channel (6). Administration takes place by pressing down the rotatable cap (4) to the limit stop, as a result of which the air present in the cylinder (7) is compressed up to a defined pressure. Once the pressure has been reached, valve (8) opens and releases the compressed air. The air is forced into the blow-out channel (6), in which the powder deposited therein is swirled up by the air stream and blown in the direction of the mouthpiece (9). In the mouthpiece (9) there are located lateral drilled holes (10) which, during inhalation by the patient, produce an injector effect in the blow-out channel. Powder conglomerates, such as occur in fine powders, are flung by the air stream, which can be amplified by the injector effect, against a nebulizing device (i.e. sieve plate) (11) where they are broken up and micronized. The baseplate (14) with mouthpiece (9) is detachable, so that the latter can be cleaned when necessary. In order to prevent the dose from being doubled, the inhaler is provided with a blocking device (e.g. a coupling which disengages on pressing down the rotatable cap--not shown), so that a new dosing can only take place once the blow-out process is complete. After the blow-out process, the rotatable cap (4) is returned again to the starting position by spring (12).