with reference to fig1 , a single medicament dose unit ( 1 ) is comprised of a spool ( 2 ), a spool carrier ( 3 ) and a single dose of medicament ( 4 ), for use in a dry powder inhaler . the spool ( 2 ) comprises a longitudinal body ( 5 ) and terminal flanges ( 6 and 7 ) at each end . the sides ( 8 and 9 ) of the flanges ( 6 and 7 ) form a seal and a tight slidable fit with the inner walls ( 10 and 11 ) of the spool carrier ( 3 ). the length of the spool ( 2 ) and the length of the spool carrier ( 3 ) are substantially the same . each flange is provided with an external face ( 12 and 13 ). with reference to fig2 and 3 , a plurality of spools ( 2 ) and carriers ( 3 ) are joined in a disc to form a magazine . the plurality of dose units ( 1 ) arranged radially around the circumference of the magazine ( 14 ). the inhalation device is provided with a dispensing mechanism ( not shown ) and a push rod ( 15 ) which also acts radially . the push rod ( 15 ) when actuated operates in the radial plane of the magazine ( 14 ) ejecting a spool ( 2 ) radially from the spool carrier ( 3 ) into the inhalation passage ( not shown ). the spool ( 2 ) remains in the plane of the magazine ( 14 ) and the flange ( 7 ) remains in co - operation with the spool carrier ( 3 ) so that it can move out of the inhalation passage upon rotation of the magazine ( 14 ). with reference to fig4 and 5 , a “ double decker ” arrangement is achieved by joining a first magazine ( 14 ) with a second magazine ( 16 ). the inhaler mechanism is provided with a first push rod ( 5 ) and a second push rod ( 17 ). the push rods may be actuated jointly , separately or sequentially optionally allowing medicament to be dispensed at the same time in the spool from the first magazine ( 14 ) as in the spool from the second magazine ( 16 ). with reference to fig6 , a spool carrier magazine ( 101 ) comprises a disc provided with a plurality of radially mounted spool carriers ( 102 ). each of the spool carriers ( 102 ) ( save for one ) is provided with a spool ( 103 ). one of the spool carriers ( 104 ) is empty and is provided with a cut away portion ( 105 ). with reference to fig7 , a pair of spool carrier magazines ( 101 a and 101 b ) are provided . a drive disc ( 106 ) comprises a substantially planar annular disc . the inner surface ( 107 ) of the drive disc ( 106 ) is provided with a plurality of teeth ( 108 ) which are adapted to engage with a drive means ( not shown ). adjacent to the periphery ( 109 ) of the drive disc ( 106 ), the disc is provided with an aperture ( 110 ) through which protrudes an out of plane resilient male member ( 111 ). the male member ( 111 ) is biased towards one of the magazines . by way of example only , the embodiment described is one in which the male member ( 111 ) is biased towards the uppermost magazine ( 101 b ), although it should be understood that the present application should be read to also encompass an embodiment in which the male member may be biased towards the other magazine ( 101 a ). the drive disc ( 106 ) is positioned adjacent to the first magazine ( 101 b ) such that the male member ( 111 ) overlies the cut away portion ( 105 ) and the empty spool carrier ( 104 ). when the second magazine ( 101 a ) is positioned in place it is arranged such that a filled spool carrier ( 102 ) overlies the male member ( 111 ). the circumferential surface rests against the male member ( 111 ) and urges it into an engaging position with the empty spool carrier ( 104 ). thus , in use , when the annular drive disc ( 106 ) is rotated , the male member ( 111 ) engages with the empty spool carrier ( 104 ) to rotate the first magazine ( 101 b ) whilst the second magazine ( 101 a ) is disengaged and therefore remains unmoved . with reference to fig8 - 10 , the assembly of the system is illustrated . thus , the assembly ( 113 ) comprises a chassis ( 114 ) and the drive disc ( 106 ) is placed above the magazine ( 101 b ). the male member ( 111 ) is biased away from the magazine ( 101 b ) and therefore protrudes above the plane of the drive disc ( 106 ). the second upper magazine ( 101 a ) is then positioned above the drive disc ( 106 ). the male member ( 111 ) comprises a substantially triangular shaped tab with a first surface ( 117 ), a second surface ( 116 ), a hinged end ( 118 ) and a distal end . optionally , the hinged end ( 118 ) may be provided with a groove ( 119 ) to facilitate the flexible movement of the male member ( 111 ). in its free position the male member ( 111 ) rests such that the first surface ( 117 ) lies in the plane of the drive disc ( 106 ) and the second surface ( 116 ) lies out of the plane and protrudes from the drive disc ( 106 ). when the second , upper magazine ( 101 a ) is in place , the lower , outer surface of the spool carrier magazine is urged against the second surface ( 116 ) of the male member ( 111 ). this urges the second surface ( 116 ) to lie in the plane of the drive disc ( 106 ) and therefore the first surface ( 117 ) lies out of the plane , enabling it to engage with the empty spool carrier ( 104 ). a push rod ( 121 ) is also provided which comprises a pair of spool prodders ( 122 a and 122 b ). the push rod ( 121 ) is connected to an actuator means ( not shown ). a chassis lid ( 114 a ) is provided to close the system . with reference to fig1 to 14 , a further embodiment is illustrated in which the male member ( 111 a ) protrudes beyond the peripheral edge ( 123 ) of the drive disc ( 106 ). the chassis ( 114 a ) is provided with two sets of guide rails ( 124 and 125 ). the device is assembled so that the male member ( 111 a ) is tensioned and the peripheral end ( 126 ) of the male member ( 111 a ) held in the guide rail ( 125 ). when the lower magazine has rotated through approximately 360 °, the male member ( 111 a ) reaches a break in the guide rails ( 124 and 125 ), thus allowing the male member ( 111 a ) to be urged towards the second magazine and into the second guide rail ( 124 ).
a delivery device , e . g . an inhaler , comprises a rotatable metering member adapted to dispense a measured amount of material , a material delivery passage and a material delivery orifice and at least one actuator member adapted to move the metering member from a material retaining position to a material dispensing position . in a magazine comprising a plurality of metering members , the actuator and metering members may operate in a radial direction . a plurality of rotatable magazines may be utilized in the delivery device . the delivery device may be used to deliver a single or a combination therapy .