This invention relates to an inhalation apparatus for dispensing substances for inhalation and, in particular, but not exclusively, for dispensing medicinal products in aerosol form from a pressurised dispensing container.
It is known to provide a sensor in an inhalation apparatus to detect inhalation by the user in order to synchronise with inhalation the release into the inhaled airflow the substance to be inhaled. It is, for example, important in the administration of aerosol products for the relief of asthma that the timing of the dispensing operation should be carefully controlled to ensure maximum deposition of substance in the user's lungs.
It is known from GB 2266466 to provide an electrically operated dispensing means responsive to a signal generated by a sensor which is responsive to a flow of air through a passageway. The disadvantage of this solution is that the apparatus is expensive.
An object of the present invention is to provide dispensing means in which mechanical means are used to co-ordinate the release of the substance with the inhalation.