US Patent 7934503 Delivery devices

A delivery device for and method of delivering substance, the delivery device comprising: a delivery outlet (7) from which substance (S) is in use delivered; a gas chamber (17) containing a gas and being of reducible volume, wherein a reduction in the volume of the gas chamber (17) to a predeterminable volume acts to pressurize the contained gas to a predeterminable pressure; a seal element (11) disposed between the gas chamber (17) and the delivery outlet (7); and an opening mechanism configured, on reduction of the volume of the gas chamber to a predeterminable volume, to open the seal element (11), whereupon a gas flow from the gas chamber (17) acts to deliver substance (S) from the delivery outlet (7).