Abstract:
An inhaler for powdered, particularly medicinal substances, is formed with a suction air duct that extends to a mouthpiece, a reservoir for the substance, and an at least linearly movable dosing chamber for separating a specific amount of the substance from the reservoir and placing the amount into a transfer position from where it is transferred to a suction air flow. In order to charge the dosing chamber by separating a specific amount of substance from the reservoir, the dosing chamber can be rotationally moved in a superimposed fashion while being arranged eccentric to a corresponding axis of rotation. A closure slide element closes off the dosing chamber in the transfer position. When suction is applied, the closure slide element moves relative to the dipping plunger into a dose-release position, whereupon the dose of the powdered substance is transferred to the suction air stream formed in the suction air duct.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of application Ser. No. 11/660,887, filed Feb. 23, 2007; which was a §371 national stage application of international application PCT/EP05/054094, filed Aug. 19, 2005; this application also claims the priority, under 35 U.S.C. §119, of German patent application No. DE 10 2004 041 524.2, filed Aug. 27, 2004; the prior applications are herewith incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to an inhaler for powdered, particularly medicinal, substances, according to the preamble of the main claim. 
     An inhaler of this general type is known from U.S. Pat. No. 5,429,122. There, the removal of a push-on closure cap results in the upward movement of the annular dosing chamber under spring force, bringing the dosing chamber into the region of a suction air stream. If the suction is not rapid and strong, small amounts of the substance being inhaled can fall downward in the air stream channel, despite suitably rapid lifting of the dosing chamber by the aforesaid spring force. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an object of the invention to provide an inhaler for powdery, in particular medicinal, substances, which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which is refined so as to provide advantages, in particular advantages relating to the charged dosing chamber. 
     With the foregoing and other objects in view there is provided, in accordance with the invention, an inhaler for powdery substances, comprising: 
     a mouthpiece and a suction air channel leading to the mouthpiece; 
     a storage chamber for storing therein the powdery substance; 
     a movable dosing chamber for apportioning a specific amount of substance from the storage chamber and moving an amount of substance into a ready position (i.e., a ready-to-empty transfer position) for transferring the amount of substance to a suction air stream; 
     a closure slide element disposed to close off the dosing chamber in the ready position, and movable relative to a dipping plunger into a dose-release position upon application of a suction underpressure. 
     In other words, according to the invention, the dosing chamber is moved into a closed delivery-ready transfer position, wherewith the dosing chamber remains closed until opened by a sufficiently strong suction air stream. The dosing chamber is moved in a helical path into the transfer position where it can deliver its contents to the suction air stream, to effect the inhalation when and if the patient provides a sufficiently strong suction air stream. This helps to avoid undesirable unmixing of the substance being delivered, which substance usually is comprised of a plurality of components. 
     According to the invention, the dosing chamber is formed in a dipping plunger which has a flattish shape, i.e., a flat-part plunger slide. 
     The flat shape of the dipping plunger enables good positioning of the axially slidable closure member in the closing position (enables effective closing by the closure member), while allowing sufficient slidability. 
     It is advantageous to have the dosing chamber in the form of a transverse bore in the flat-part dipping plunger. 
     In this connection it has been found to be particularly advantageous if the dipping plunger is movable by means which are dependent upon manipulations of the closure cap, so that in the course of carrying out the customary manipulations for closing and opening of the device, the rotation of the closure cap will also cause charging of the dosing chamber and a helical movement of the dosing chamber into the closed ready-to-release transfer position. 
     It is particularly effective if the transverse bore comprising the dosing chamber has a (frusto)conical shape. 
     The cross sectional dimensions of the flattish piece of which the dipping plunger is comprised have a ratio in the range of approximately 1:2 to 1:5. The flattish cross section of the dipping plunger favors the breaking up and loosening of the subject substance stored in the central region of the storage chamber, and promotes the progression of the dipping plunger into the mass of powder and the complete charging (of the dosing chamber). 
     The axially slidable closure member is linearly movable relative to the dipping plunger; the flattish dipping plunger throughgoingly extends through the slidable closure member in rotationally rigid fashion but in a manner such that the friction between the two components is low. 
     The end of the dosing chamber having the larger open diameter is associated with an air passage of smaller diameter than the end of the dosing chamber, and the end of the dosing chamber having the smaller open diameter is associated with a second air passage of larger diameter than the smaller end. This tends to provide a larger underpressure on the end with the larger open diameter. 
     It is further proposed according to the invention that the air passages are formed in a cup-shaped rotary piece which guides the dipping plunger, and the air passages are in fluid communication with air inlets in the shell (lateral wall) of the mouthpiece. The air inlets are located in the shell of the mouthpiece at locations chosen such that neither the patient&#39;s lips nor the hand by which the patient generally surroundingly holds the generally stick-shaped device will occlude the air inlets. 
     A plurality of air inlets may be provided which are disposed at mutual distances, in order to further minimize the risk of air inlet occlusion. 
     To promote good distribution of the powdered substance in the suction air stream, the air passages may be axially displaced with respect to the air inlets, which may be closer to the mouthpiece. The effect of this is that, upon opening of the device, the flow path will be U-shaped. 
     It has further been found advantageous if the generally cup-shaped bottom of the rotary part forms the cover for the storage chamber, and the center of the cup-shaped bottom has a guide opening for the dipping plunger. The cup-shaped bottom thus has a dual function—serving as a direct or indirect cover, and serving as a guide for the dipping plunger. 
     It is also advantageous if the dipping plunger, which is to some extent tapered toward its dipping end in the manner of the blade of a screwdriver, is rotationally connected to the rotary part by means of radial lobes. The blade-like tip region provides a rotational breaking up and loosening effect, and also facilitates insertion of the dipping plunger into the powder mass; and the radial lobes help to support the dipping plunger with respect to the rotary part and to assist in maintaining the positioning of the air passages with respect to the dosing chamber. 
     Simple means are provided to facilitate the necessary linear relative movement of the dipping plunger and the rotary part, which means may comprise axial guide grooves in the cup-shaped wall of the cup-shaped rotary part, in which grooves the aforethe lobes are guided. 
     According to a further feature of this solution, a stroke-limiting detent for the dipping plunger is provided, which detent, via its base wall section, defines the ready-to-empty position (transfer location) of the dosing chamber. 
     The positioning of the dipping plunger based on manipulation of the closure cap is aided by a feature according to which a “docking point” (docking position structure) is provided which is disposed at or near the mouthpiece end which docking position structure has latching means whereby the dipping plunger and the closure cap can interengage, which latching means can be disengaged by application of force tending to pull the plunger and cap mutually apart. When the inhaler is re-closed, the dipping plunger and closure cap are mutually re-engaged by mutual thrust, giving rise to a “re-docking.” 
     According to an important refinement, the rotary piece has a rotor, and a corresponding stator, the rotor and stator cooperating to provide a shoveling effect to deliver (material) to the dosing chamber when the rotary piece is “rotated back.” With this arrangement, from one instance to another of filling of the dosing chamber the amount of the powder charged, and its density, remains constant. Also, the shoveling action tends to loosen the nearby powder mass, thus tending to prevent caking and lumping of the powder particles. The phrase “rotated back” refers to the effect of unscrewing of the closure cap, which is accompanied by charging of the dosing chamber. The shoveling mechanism is comprised of rotor blades borne on a cantilever structure wherewith they extend from a ring-shaped disc member at the bottom of the rotary part. 
     It is also proposed that the closure cap is in the form of a screw cap and cooperates with the mouthpiece via rotational (which is to say non-rotation) engagement means. The latter have a deep notch or forked structure and are configured so as to disengage when the cap is ultimately unscrewed. 
     To further improve the distribution of the powdered substance or the apportioned amount of substance in the suction air, the so-called dispersing region, downstream of the transfer region in the direction of flow, is further formed in an advantageous way to the extent that the suction air channel has a radially outward deflection above the dosing chamber. Accordingly, before the amount of substance transferred to the suction air stream leaves, it also undergoes a deflection, this radially outward deflection also leading into an outlet portion in the region of the mouthpiece that is similar to an annular space. Correspondingly, the substance leaves in the form of a circular ring if the mouthpiece is viewed looking down on top of it. It is also proposed that the plunger slide itself forms part of the flow deflection, for instance in particular such that, in an end region facing away from the flat part having the dosing chamber and correspondingly facing toward the mouthpiece, it takes the form of a disk of a circularly round outline, which offers the radially outward deflection of the suction air channel in the transfer position. 
     Other features which are considered as characteristic for the invention are set forth in the appended claims. 
     Although the invention is illustrated and described herein as embodied in inhaler for powdered, particularly medicinal substances, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
     The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     The invention is explained in more detail below with reference to the accompanying drawings, which merely represent an exemplary embodiment and in which: 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         FIG. 1  shows the inhaler according to the invention in side view, enlarged, in the basic position with the cap closed; 
         FIG. 2  shows the vertical section of this; 
         FIG. 3  shows an enlargement taken from  FIG. 2 , for the region of a dosing device; 
         FIG. 4  shows a sectional representation according to  FIG. 2 , but with the closure cap removed and resultant displacement of the dosing chamber into the ready-to-remove position; 
         FIG. 5  shows a sectional representation corresponding to  FIG. 4 , but representing a position in the course of inhalation; 
         FIG. 6  shows the plunger slide having the dosing chamber on its own in elevation; 
         FIG. 7  shows the side view of this; and 
         FIG. 8  shows the plunger slide in a perspective representation, with a closure plunger that can be associated with it and with a sealing bush. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the figures of the drawing in detail, there is shown and described an inhaler  1 , which is realized as a conveniently portable pocket device in the form of a short stick, with a shape-determining stepped cylindrical housing  2 . 
     The cylindrical housing which is like a small tube passes at the top end of the inhaler  1  into an attached mouthpiece  3  which is flattened appropriately for a mouth and can be protectively engaged over by means of a cup-shaped closure cap  4 . The latter is realized as a screw cap, for which purpose an internal thread  5  associated with it engages in a corresponding external thread  6  on the lateral wall of the housing  2 . In the region where the mouthpiece  3  is attached/a clip  7  is integrally formed on the outer sleeve wall of the closure cap  4 . 
     At the bottom end, the end edge of the cup-shaped closure cap  4  butts with a stop-limiting and sealing effect against an annular shoulder  8 , which is achieved on account of the aforementioned step of the cylindrical housing  2 . 
     The closure cap  4  serves at the same time as an actuating handle  9  for delivering a powdered substance in reproducible portions  10 ′, for which purpose the axial screw stroke of the engagement of the threads  5 / 6  is used. The substance  10  is accommodated in a storage chamber  11  of the housing  2  in an optionally refillable manner. The dosing device, transporting in each case a portion  10 ′ to a transfer point U lying outside the storage chamber  11 , is designated as a whole by D. 
     With respect to the material that can be dosed, it is a medical, powdered substance  10 . For example, basic substances capable of being transported by suction stream, such as lactose, may act as a carrier for micronized fine particles of medicament sticking to the surface. 
     Provided downstream of the dosing device D is a so-called dispersing region, in which the user produces a suction air stream S. This completely carries away the exactly apportioned amount  10 ′ of the substance  10  at the transfer point U. The suction air channel leading to the mouthpiece  3  is provided with the reference numeral  12 . 
     The lower termination of the storage chamber  11  is formed by a cup-shaped pressure-exerting base  13 , which is under spring loading in the direction of the mouthpiece  3  by means of a compression spring  14 . The compression spring  14  is supported by the bottom end turn on a base cap  15  closing the housing  2  there. The base cap is in latching engagement with the portion of the housing  2 , which is here of larger cross-section, a corresponding latching collar  16  of the base cap  15  engaging in a matching annular groove of the housing  2 . 
     The top end turn of the prestressed compression spring  14  acts in loading manner on an inner shoulder  17  of a hollow piston  18  of the piston-shaped device  13 / 18 . As can be gathered from the illustrations, the stepped cup-shaped pressure-exerting base  13  is connected in a latching manner to the inner shoulder  17  of the hollow piston  18 . 
     The cup edge of the pressure-exerting base  13  provides an annular lip  19 , which on account of its rubberelastic material wipes off the wall of the storage chamber  21  without any substance being lost. 
     A hollow standing spigot  20  extends centrally from the base cap  15 . Together with the hollow piston  18  surrounding it at a spacing, the standing spigot forms a spring chamber  21  for the compression spring  14 . 
     At the mouthpiece end, the storage chamber  11  terminates with a cup-shaped rotary part  22 , which forms by its cup base the top  23  of the storage chamber  11  engaging over the housing  2 . 
     A guiding opening  24  is left at the center of the top  23 . This indirectly or directly formed guiding opening  24  receives a plunger slide  25 , as the key component of the dosing device D. As a result of being appropriately configured, the plunger slide acts as a moving dosing chamber  26  for the portion  10 ′ to be lifted out, the movement of the plunger slide  25  taking place linearly in the longitudinal center axis x-x of the substantially rotationally symmetrically configured inhaler  1 , overlaid by a rotational movement carried out about this longitudinal center axis x-x. The plunger slide  25  is fashioned substantially as a flat part with an elongate rectangular cross-section. The length ratio of the narrow side to the wide side in the exemplary embodiment represented is approximately 1:3. 
     At the end remote from the mouthpiece  3 , the plunger slide  25  forms a point similar to a screwdriver blade. The two mirror-symmetrical oblique flanks extend here from the respective wide sides of the plunger slide  25 . The free end, provided with the oblique flanks, is blunted. 
     On account of the co-rotation of the plunger slide  25 , the cross-sectional configuration of the plunger slide  25  and the pointing of the free end region have a loosening effect in the central region with respect to the mass of powdered substance  10 . 
     The stroke of the dosing chamber  26 , moving in a linear manner with superposed rotational movement, makes allowance in both end positions of the plunger slide  25  for the cross-section of the guiding opening  24  to be kept closed with a doctor-blade or wiping-off effect, filling the dosing chamber, over the length of the opening  24 . 
     The end of the closure cap  4  for the mouthpiece forms a docking point  28  between plunger slide  25  and closure cap  4  that unlatches when overloaded. The latching means on the closure cap is in this case a ring of hooks capable of resilient deflection. The corresponding end of the plunger slide  25  is fashioned in a rotationally symmetrical manner in cross-section, a disk-shaped radial collar  29  also emerging in the transitional region from the flat part portion to the cylindrical end portion. With an axial spacing in relation to this radial collar  29 , the end region of the plunger slide  25  that is facing away from the flat part fashions a latching head  30 . Between the latching head and the radial collar  29  there is formed a narrow waist-like annular groove  31 . Inwardly directed lugs  32  of the resilient tongues of the ring of hooks engage in the annular groove. The latching head  30  can be overcome in both directions by the lugs  32 . 
     The lugs  29 , or their resilient tongues, are realized on a small tube  33  which protrudes into a central mouthpiece opening  3 ′ and extends from the inner side of the top of the closure cap  4 , at which it is rooted. 
     The mouthpiece  3  acts via a lateral wall  34  in an anchoring manner on the neck of the housing  2 . With reference to the illustrations, this anchorage is formed underneath the top  23  of the rotary part in the form of a latching point  35  between the two parts  2 ,  3 . It may be an irreversible latching point  35 . In addition, the top  23  of the rotary part  22  is engaged over in a supported manner by an annular shoulder  36  of the lateral wall  34 . 
     The central opening  3 ′ of the mouthpiece  3  is formed in the region of a cup-shaped dispersing part  37 , disposed substantially in an inverted position. This is accomplished by passing centrally through the base  38  of the dispersing part. The dispersing part  37 , opening in the direction of the rotary part  22 , has a cup wall  39 , with an outside diameter which corresponds to the outside diameter of the cup wall  40  of the rotary part  22 . The cup-shaped rotary part  22  and the cup-shaped dispersing part  37  face each other with their openings, the dispersing part  37  being supported with its free annular edge on the associated annular edge of the cup wall  40  of the rotary part. 
     Both cup walls  39  and  40  are spaced radially inward in relation to the inner wall of the lateral wall  34 . Correspondingly, an annular space  41  is respectively obtained around the rotary part  22  and around the dispersing part  37 . 
     The inside diameter of the cup wall  39  of the dispersing part  37  is adapted to the outside diameter of the disk-like radial collar  29  of the plunger slide  25 . The latter correspondingly undergoes guidance in a linear direction in the cup-like dispersing part  37 . 
     Respectively toward their open end regions, the cup spaces both of the rotary part  22  and of the dispersing part  37  widen radially outward, with the material of the respective cup walls  39  and  40  being reduced. As a result of this configuration, a radially widened overflow region  42  is obtained. 
     Spaced away from the cup base  38  of the dispersing part  37  by approximately the material thickness of the radial collar  29  of the plunger slide  25 , radial passages  43  are provided in the cup wall  39 , for connecting the space inside the cup with the peripheral annular space  41 . As shown, two diametrically opposed passages  43  may be provided. 
     Alternatively, one peripheral passage, interrupted by supporting webs, may also be provided. The annular discharge space  44 , surrounding the cup base  38  of the dispersing part  37  is separated from the annular space  41  extending approximately as an axial extension by a sealing collar  45 , which protrudes radially outward on the cup wall  39 , which sealing collar  45  is supported on the inside of the lateral wall  34 . As a result of this configuration, a defined deflection of the suction air channel  12  is achieved, from the central axial alignment radially outward into the substantially axially aligned annular outlet space  44 . 
     The axial lengths of the rotary part  22  and the dispersing part  37  in the region of their cup walls  39  and  40  are chosen such that the powder-drawing plunging stroke of the plunger slide  25  out of a filling plane in the storage chamber  11  to the transfer point U above the top  23  is ensured. 
     The defined ready-to-empty position of the dosing chamber  26  is obtained by an extension limiting stop of the plunger slide  25  in the region of its radial collar  29  against the cup base  38  of the dispersing part  37 . 
     The dosing chamber  26  is realized as a transverse bore running substantially perpendicularly in relation to the longitudinal center axis x-x. 
     This longitudinal center axis x-x at the same time forms the axis of rotation. The dosing chamber  26  is eccentrically disposed with respect to this axis of rotation, so furthermore passes through the wide sides of the plunger slide  25  fashioned as a flat part. As can be gathered in particular from the illustration in  FIG. 2 , the dosing chamber  26  is disposed such that it is associated with a side edge of the wide surface, at a spacing from the free end of the plunger slide  25 . 
     In the ready-to-empty position according to  FIG. 4 , the dosing chamber  26  is in the active region of the central suction air stream S. An air passage  46  connecting with the suction air channel  12  and formed in the cup wall  40  of the rotary part  22  is associated with the dosing chamber  26 . The air passage comprises radial bores which extend in the vicinity of the base of the cup-shaped rotary part  22  with an axial spacing above the upper side of the top  23 . 
     Such an air passage  46  is provided upstream and at a radial spacing from both open ends of the dosing chamber  26 . One precaution in this connection is that associated with the end of the dosing chamber  26  which is of larger clear diameter and is formed by a conical transverse bore is an air passage  40  of a smaller diameter than the larger-diameter end and associated with the end of the dosing chamber  26  which is of smaller clear diameter is an air passage  46  of a larger diameter than the smaller-diameter end. This way there is produced a greater reduced pressure with a predominant discharging effect with respect to the administered portion  10 ′ downstream of the air passage  46  of smaller diameter. Nevertheless, the discharge, i.e. emptying of the dosing chamber  26 , takes place from both ends. A solution in which the air passages  46  are of the same diameter is shown in the drawings. 
     The air passages  46 , formed on the cup-shaped rotary part  22  guiding the plunger slide  25 , are also in flow communication with air inlets  48  spaced radially by way of a rearward annular inflow space  47 . The air inlets are also configured as bores and represent the connection to the atmosphere. The annular inflow space  47  is fashioned between the outer side of the cup wall  40  of the cup-shaped rotary part  22  and the inner side of the lateral wall  34  of the mouthpiece  3 , as an axial extension of the annular space  41  described. A stepped, radially outwardly protruding sealing collar  49  at the end facing toward the cup opening of the dispersing part  37  serves for separating the annular spaces from one another and for the radial alignment of the dispersing part  37  while supported on the inner side of the lateral wall  34 . The sealing collars  49  and  45  of the dispersing part  37  prevent a flow bypass between the air inlets  48  and the annular outlet space  44  in the region of the mouthpiece  3 . 
     The air passages  46  are disposed axially offset in relation to the air inlets  48 , the latter lying closer to the mouthpiece  3 . The described spatial distancing leads to an initially contra-acting inflow of sucked-in air following on from the main suction air stream S. 
     The guiding opening  24  for the plunger slide  25  is formed such that it has a wiping-off effect, as a result of which there is also no dosage-falsifying entrainment of powder material that may be sticking to the lateral surface of the plunger slide. The guiding opening  24  is not formed directly by the rotary part  22 , but by a sealing bush  50  lining this passage. The sealing bush consists of rubber-elastic material and is held by being clipped into the top  23  by latching means. 
     Between the rotary part  22  and the housing  2 , which forms the storage chamber  11 , there is likewise a sealing element. This is achieved by a sealing ring  51  of rubber-elastic material inserted between the inside wall of the storage chamber  11  and the rotary part  22 . The sealing ring is fitted under preloading in annular grooves of both parts  2 ,  22 . Both of the peripheral annular grooves, which accommodate the sealing ring  51 , have a half-round cross-sectional configuration. The corresponding regions of the sealing ring  51  are correspondingly shaped. 
     The sealing bush  50  is connected to the rotary part  22  in a rotationally fixed manner. The guiding opening  24  is formed in a manner adapted to the cross-sectional configuration of the plunger slide  25 , likewise in an elongate rectangular fashion, and as a result of this positive engagement the plunger slide  25  is also connected to the rotary part  22  in a rotationally fixed manner. 
     Interacting with the plunger slide  25  is a closure plunger  52 , which is movable in relation to the latter outside the storage chamber  11 . The closure plunger may consist of a rubber-elastic material and is passed through centrally by the flat portion of the plunger slide  25 , for which purpose the closure plunger  52  has a matched bearing opening  53 , of an elongate rectangular form in outline. This bearing opening  53  is slightly enlarged with respect to the cross-sectional dimension of the flat portion of the plunger slide  25 , as a result of which a low-friction displacement of the closure plug  52  on the plunger slide  25  is achieved. 
     The closure plunger  52  is provided with a radially outward peripheral sealing lip  54 , which in a ready-to-transfer position according to the illustration in  FIG. 4  interacts with the inside wall of the cup wall  40  of the rotary part, this being above the air passages  46  with reference to the storage chamber  11 . 
     In this ready-to-transfer position, the closure plug  52  is located in a blocking manner in the suction air channel  12 , with the dosing chamber  26  that is provided with the portion  10 ′ of the substance  10  being sealed off on both sides. If the inhaler  1  is put down after it has been activated, that is to say after the plunger  25  slide with the filled dosing chamber  26  has been displaced into the ready-to-transfer position, this does not lead to loss of the apportioned amount from the dosing chamber  26  as a result of the way in which the closure plunger  52  is disposed. The closure plug  52  is fashioned in a self-locking manner. 
     The displacement of the closure plunger  52  is only possible deliberately, most easily by activation of the suction air stream S, that is to say by the customary intake of inhalation. Depending on the reduced suction pressure that this produces, the closure plunger  52  is displaced axially upward along the portion comprising the flat part of the plunger slide  25 , to release the dosing chamber  26  on both sides. The closure plunger  52  is hereby moved into the radially widened overflow region  42 , this axial displacement being stop-limited. Serving for this purpose are axially aligned stop webs  55 , which extend radially inward from the inside wall of the cup wall  39  of the dispersing part and against which the annular sealing lip  54  of the closure plunger  52  butts in a blocking manner. The radial spacing of the stop webs  55  from one another corresponds to the guiding cross-section of the dispersing part  37  and consequently to the outside diameter of the radial collar  29  on the plunger slide side. 
     In the course of the inhalation as schematically represented in  FIG. 5  flow passes around the closure plunger  52 , lying in the region  42  of the mouthpiece  3   
     Conducive to the emptying of the storage chamber  11  is the way in which the powdered substance  10  is kept ready in the drawing region. Conditions are created to ensure an isostructural or homogeneous filling of the dosing chamber  26 , fed from a surrounding region where the substance has been loosened. The rotary part  22  is used in particular for this purpose. It has a rotor R acting in the upper region of the storage chamber  11 . Using the rotation of the rotary part  22 , a loosening of the stored substance is obtained. Rotor blades  56  form a scoop. In this respect, two rotor blades  56  may be provided, disposed diametrically opposite with respect to the longitudinal center axis x-x of the inhaler  1 . The freely extending rotor blades  56  protruding from the base or the top  23  of the rotary part  22  on the storage chamber side are positioned diametrically opposite in such a way that they are sufficiently spaced apart in the circumferential direction. Geometrically, they may substantially take up a quarter sector of the circular cross-section of the storage chamber  11 . 
     In interaction with the plunger slide  25  fashioned as a flat part, the way in which the rotor blades  56  are disposed always achieves a surrounding region where the substance has been loosened. Furthermore, the way in which the dosing chamber  26  is disposed eccentrically in relation to the axis of rotation of the plunger slide  25  achieves optimum filling of the same by means of plunging helically through the mass of substance. 
     The co-rotation between the mouthpiece  3  and the closure cap  4 , lifting off by an unscrewing action, takes place by a claw coupling  57  between the two. This comprises a longitudinal toothing  58  on the lateral wall  34  of the mouthpiece  3 , which longitudinal toothing  58  engages in corresponding tooth gaps  59  on the inner side of the closure cap  4 . 
     As the closure cap  4  is lifted off by an unscrewing action, the claw coupling  57  causes a co-rotation of the rotary part  22  and of the parts entrained by it, such as the sealing bush  50 , the closure plug  52  and  25  the plunger slide  25 , an axial displacement of the plunger slide, brought about by the screw-effected lifting-off displacement of the closure cap  4 , being in addition effected by the docking point  28 , this axial displacement bringing about a screw-thread-like displacement of the dosing chamber  26  to the transfer point U, that is to say into the ready-to-transfer position according to the illustration in  FIG. 4 . In the course of the linear displacement of the plunger slide  25 , the closure plug  52  remains in its sealing position, supporting itself on the top  23  of the rotary part  22 . 
     The standing spigot  20  rooted at the base  15  of the housing  2  is closed at the end by a screen-like cover  60 . In the delimited space created as a result, a moisture-absorbing material  61  is held. 
     The plunger slide  25  can be varied with respect to the volume of its dosing chamber  26 . All that is necessary for this is to exchange the key component of the dosing device D, that is the plunger slide  25 , to achieve a different, precisely reproducible dosing of portions  10   
     The pressure-exerting base  13 , acting in the manner of a plunger, is not impaired in its ability to move with respect to the cylinder space, which is provided by the central portion of the housing  2 , since there the housing has an air-equalizing opening  62  lying to the rear of the annular lip  19 . 
     The cup-shaped pressure-exerting base  13  has a central indentation, directed away from the storage chamber  11 . It is of such a depth on the inside that the end portion of the plunger slide  25  projecting axially downward beyond the rotor blades  56  in the basic position is accommodated in it. 
     All features disclosed are (in themselves) pertinent to the invention. The disclosure content of the associated/accompanying priority documents (copy of the prior patent application) is also hereby incorporated in full in the disclosure of the application, including for the purpose of incorporating features of these documents in claims of the present application.