摘要 |
An inhaler for administering powder by inhalation and a method of constructing the same, the inhaler comprising: a housing having a screw thread (28) and a substantially circular sealing surface (40) coaxial therewith; a mouthpiece (2) attached to the housing; and a cap (14) for covering at least the mouthpiece (2), the cap (14) having a screw thread (17) for engaging the screw thread (28) on the housing and a substantially circular sealing surface (15) for engaging the sealing surface (40) on the housing; wherein the sealing surfaces (15, 40) are shaped and dimensioned such that the radial force therebetween is substantially constant for any relative position where the sealing surfaces (15, 40) engage one another. |