초록 ▼

A metered dose inhaler comprises a piston which is mounted in a cavity within a body, and is urged by a pre-loaded spring into a reduced cross-section pressure chamber. The piston may be loaded by means of an actuating rod having a handle, and may be latched in a loaded position by a latching means.

A metered dose inhaler comprises a piston which is mounted in a cavity within a body, and is urged by a pre-loaded spring into a reduced cross-section pressure chamber. The piston may be loaded by means of an actuating rod having a handle, and may be latched in a loaded position by a latching means. A liquid drug (e.g. in aqueous solution) is contained in a collapsible bag. Metered quantities of the drug are successively presented in the pressure chamber, and then subjected to a sudden and great increase in pressure, to eject the liquid drug through an atomising head, to reduce it to fine atomised spray of small mean particle size－for example less than 30 micrometers. Non-return valves control the flow of liquid through the device. The sudden pressure pulse is caused be releasing the spring loaded piston, upon depressing an actuating button connected by the latching means.

대표청구항 ▼

A device for dispensing fluid as a spray of droplets, comprising: a chamber for containing fluid at a first pressure; a piston for pressurizing and discharging the fluid in said chamber, wherein said piston is reciprocable between a loaded position and a discharge position; resilient biasing means f

A device for dispensing fluid as a spray of droplets, comprising: a chamber for containing fluid at a first pressure; a piston for pressurizing and discharging the fluid in said chamber, wherein said piston is reciprocable between a loaded position and a discharge position; resilient biasing means for urging said piston from the loaded position to the discharge position thereby subjecting the fluid in said chamber to a predetermined increase in pressure from said first pressure to a second pressure of at least 50 bar to permit discharge of the fluid from said chamber at said second pressure, wherein said resilient biasing means is in a loaded state when said piston is in the loaded position; latching means for holding said resilient biasing means in the loaded state; actuating means for releasing said latching means, wherein release of said latching means releases said resilient biasing means from the loaded state and said resilient biasing means urges said piston from the loaded position to the discharge position thereby initiating discharge of the fluid from said chamber at said second pressure; and atomising means for atomising the fluid discharged from said chamber.