Metered dose inhalers
Assignee3M Innovative Properties Company
InventorPhilip A. Jinks
Life of this patent
Estimating the term…
Abstract
The present invention addresses the problem of turbophoresis and provides a relatively simple and low cost solution for a metered dose inhaler, in particular, a pressure-actuated metered dose inhaler. A metering valve (100) comprises a valve body (110), a valve stem (130) mounted within the valve body (110) and a spring element (140) for biasing the valve stem (130) in an “at rest” position. A pre-metering region (170) is formed in the valve stem (130) which is provided with a miniature valve seal (210) at its inlet (180). The miniature valve seal (210) effectively isolates the pre-metering region (170) from surrounding bulk formulation (4) within a canister (1) in which the metering valve (100) is mounted when the valve stem (130) is in the “at rest” position.
Claims17
A metering valve comprising:
- a housing;
- a valve body mounted in the housing, the valve body having an inlet;
- a valve stem moveable within the valve body between at least a first position and a second position with respect to the valve body;
- a return member located within the valve body and being operable for biasing the valve stem to the first position;
- a pre-metering region formed within a first portion of the valve stem, the pre-metering region including an inlet port and an outlet port, the inlet port being connected to the inlet of the valve body;
- a metering chamber formed between the valve stem and the valve housing, the metering chamber being connectable to the outlet port of the pre-metering region;
- a first dose retention element positioned in an inlet path to the pre-metering region and being operable for retaining a measured dose within the pre-metering region, the first dose retention element providing fluid transport in both directions therethrough;
- and
- a dispensing channel formed within a second portion of the valve stem, the dispensing channel having a dispensing inlet and a dispensing outlet, the dispensing inlet being connectable to the metering chamber in the second position.
Dependencies are inferred from the claim text.