Patent ID: 8905020

Claim:
A spacer for delivering a medicinal substance to a user, the spacer comprising: a chamber comprising, tubular member at least partly defining a first reservoir, the top end of the tubular member narrowing to define a single unobstructed central chamber aperture, a base for the tubular member having an inlet for admission of the medicinal substance into the first reservoir, a vented member disposed on the tubular member, the vented member defining multiple transverse apertures positioned around the central chamber aperture and multiple circumferential apertures perpendicular to, at least partly beneath, and adjacent to, the transverse apertures, the transverse apertures forming the opening of a vent, which vent passes to and ends in the circumferential apertures, a mouthpiece disposed on the vented member, the mouthpiece partly defining a second reservoir, the mouthpiece having an outlet for withdrawal of the medicinal substance from the second reservoir, and a valve located at least partly within the chamber, the valve comprising, a retaining portion which is retained by a part of the chamber, a first flow control portion forming a dome structure at rest which is anchored by and extends upwardly from the retaining portion, the dome structure being self-supporting so as to inherently resist against collapse beyond its resting state on exhalation by a user, the dome structure defining a central cross slit proximate its peak, the first flow control portion being adapted to open during user inspiration, thereby allowing forward-flow of the medicinal substance from the first reservoir to the second reservoir, and adapted to close during user expiration, thereby substantially limiting backflow of the medicinal substance from the second reservoir to the first reservoir, and a flat ring shaped second flow control portion which surrounds the first flow control portion, is anchored by the retaining portion, and has a circumferential free edge, the diameter of the second flow control portion being approximately twice the diameter of the first flow control portion, the second flow control portion being adapted to close during user inspiration, thereby closing off the transverse apertures and substantially limiting inflow of air through the vent into the second reservoir, and adapted to open during expiration, its free edge flapping downwardly away from the transverse apertures and beneath the roof of the circumferential apertures, thereby allowing expulsion of air from the second reservoir through the vent.