Inhaler

Abstract

An inhaler is provided with a baffle for changing the effective size of the passage for passing the suspension to be inhaled in such a manner that the centre of the effective aperture left by the baffle moves towards the jet of the inhaler when the aperture is increased in size and moves away from it when the aperture is reduced in size.

Description

The present invention relates to inhalers for producing suspensions of liquid or pulverulent materials, and more particularly though not exclusively to such inhalers as comprise a suspension outlet opening which is comparatively large in size in comparison with the jet of the inhaler, and means for adjusting the quantity of suspension produced.

In the context of such inhalers the proposal has already been made to alter the pressure of gas used for atomisation or, in accordance with the German Pat. No. 927,920, to adjust the cross-section of a passage serving for the supply of additional air supplied for atomisation.

In order to change the size of the suspended liquid or solid particles in accordance with needs arrising it has been necessary with prior art devices to change the jet or nozzle used for atomisation or replace the nozzle by a different nozzle.

One object of the invention is to provide an inhaler of the type described above in which a simple manipulation is sufficient to adjust the quantity of suspension and also the size of the suspended particles during operation as may be required. A further object of the invention is to provide an inhaler which provides a finer suspension when the quantity of suspension is reduced.

The present invention consists in an inhaler for administring a suspension of particles, comprising a nozzle for entraining the particles, and a duct for guiding the particle suspension to a patient for inhalation, the duct defining a suspension outlet opening with a cross-section which is considerably larger than the internal cross-section of the nozzle, and a baffle which is arranged to cooperate with the duct in varying the size of the outlet opening, the centre of the effective opening being moved towards the jet when the opening is increased in size and moved away from it when the baffle is moved to reduce the size of the opening.

Generally the suspension particles become finer with the increase in the distance from the nozzle, since the coarser particle settle more readily. Consequently as the baffle is moved so as to bring about an increasing closing of the opening only the fine particle leave the inhaler and, with a suitable construction of the apparatus, fall back into means for storing the liquid or powder to be inhaled.

Preferably the baffle is arranged to rotate and can be constructed as a cylindrical baffle which is coaxially arranged in a suitable tube forming part of the duct, through which the suspension leaving the nozzle region passes upwards. In this case an aperture for the suspension is left in the tube and this aperture can be closed to a greater or lesser extent by the baffle. If the tube is arranged vertically the deposit of the coarser particles occurs to a greater degree so that there is a guarantee that as the opening is closed to a greater and greater extent only fine suspension particles will leave the inhaler. In order to ensure that there is a linear relationship between movement of the baffle and change in the size of the opening the closing edge of the baffle can be made helical.

Further details of the invention will be gathered from the following description of a preferred embodiment of it referring to the accompanying drawings.

FIG. 1 is a longitudinal section through the inhaler.

FIG. 2 is a front view of the upper part of the inhaler in which the suspension outlet opening can be seen with the baffle in the open position.

FIG. 3 is a similar view with the baffle closed.

FIG. 4 is a view of the baffle removed from the rest of the inhaler.

FIG. 5 is a plan view of the baffle looking in the direction of its axes of rotation.

The inhaler shown in FIG. 1 comprises a base 1, which together with a screwed-on intermediate part 2 forms a handle for holding the inhaler. In the intermediate part 2, in which the medium 3 to be suspended is contained, the atomising or suspending nozzle 4 is mounted, which is provided with a central air channel 5 and suction channels 6 on both sides of it for the medium to be suspended.

The air channel 5 is connected with an air duct 7 of larger cross-section which passes transversely through the base 1 and is connected with a nipple 8 for a compressed air hose. A discharge opening 9 at the other end can be closed as desired by a rubber button 10 on an actuating lever 11 so that the compressed air supplied to the inhaler is only forced to pass through the nozzle 4 when the lever 11 is operated. In this manner it is possible to use the inhaler only during actual breathing in.

Directly above the nozzle there is a gas flow deflector 12 which in a conventional manner aids in atomisation.

On the intermediate part 2 a substantially cylindrical tube 13 is screwed which forms a continuation of the intermediate part. This tube has a suspension outlet opening 14 in its side (see FIG. 2), which has a cross-section which is large in comparison with the internal cross-section of the nozzle. The opening adjoins a breathing mask 15.

The tube 13 is closed at its free upper end except for a coaxial hole which is defined by an inwardly projecting lip or neck 16. A tubular inlet sleeve 17 is mounted in the lip 16 so that it can rotate and serves for the supply of additional air into the inhaler.

The baffle 19 is mounted on the sleeve 17 by means of a connecting piece 18 (FIG. 5). The baffle 19 surrounds the axis of the sleeve 17 concentrically and in developed view has approximately the shape of a right-angle triangle or trapezium. Accordingly the closing edge 20 of the baffle 19 has a helical shape.

The feature that the closing edge is on the side of the baffle 19 removed from the nozzle 4 is especially important to ensure that the suspension outlet opening 14 is closed in such a manner that its centre moves upwards during the process of closing of the opening. This ensures that on reducing the size of the suspension outlet opening at the end of the movement only the finest particles can leave the device while the coarser particles are deposited adjacent to the nozzle or owing to the reduced gas speed fall back into the liquid or powder with which the inhaler has been charged.

With the inhaler described it is possible by a simple manipulation not only to adjust the rate of supply of the suspension but also to regulate the particles size as may be desired, a knurled ring 21 being provided at the outer end of the suction sleeve 17. On rotating the sleeve 17 the baffle 19 is also rotated so that the suspension outlet opening is closed to a greater and greater extent as can be seen from FIGS. 2 and 3.

It is naturally possible to make modifications in the embodiment of the invention specifically described. More particularly the device in accordance with the invention can be used for purposes other than inhalation purposes.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are as follows:

1. An inhaler for vaporizing and atomizing liquid or pulverulent materials, comprising:

a. a chamber for liquid or pulverulent material,

b. a source of gas under pressure,

c. nozzle means communicating with the chamber and the source for entraining the liquid or pulverulent material with the gas,

d. passage means communicating with the nozzle on one end and defining an outlet opening on the other end for directing an entrained mixture to an inhalor, and

e. adjustable baffle means rotatably mounted adjacent the opening and having an inclined, helical closing edge remote from the nozzle and extendable across the opening, whereby the closing edge moves away from the nozzle when the opening is reduced.

2. An inhaler in accordance with claim 1 in which the baffle means is coaxially mounted with respect to the passage means and wherein the closing edge cooperates with the opening to define the effective cross-sectional area thereof.

3. An inhaler in accordance with claim 1 in which the passage means is substantially vertical in normal operation.

4. An inhaler in accordance with claim 2 further comprising a sleeve member on which the baffle is mounted for introducing air into the inhaler.