A portable
oxygen dispenser for providing an
emergency supply of
oxygen-rich gas includes a closed cannister defining a cannister axis and
diameter and containing a quantity of pressurized,
oxygen-rich. A dispensing orifice includes an externally actuable valve at one axial end of said cannister for maintaining the orifice normally closed. The valve includes a
nozzle stem generally arranged along the cannister axis. An annular neck wall is generally concentrically arranged about the
nozzle stem and dimensioned to form an annular space between the
nozzle stem and the neck wall. A generally conical diffusing member defines a
diffusion axis and opposing axial ends, one of which is a dispensing open end dimensioned to substantially correspond to the cannister
diameter; the other end is a closed infusion end and is provided with an inlet opening defining an axis generally transverse to the
diffusion axis and structure for engaging the stem for selectively applying an
axial force to the nozzle stem. The dispensing end is configured to fit over the cannister when not in use. The cannister and the
diffusion axes are generally aligned and adapted to be placed over the mouth and / or
nose of a user. A protective guide extends into the annular space slidingly engaging the annular neck wall for substantially limiting the forces applied to the nozzle stem to axial forces along the cannister axis. In this way, forces on the nozzle stem other than the axial forces along the cannister axis are avoided, thus preventing damage to the nozzle stem during use of the diffusing member.