Abstract:
A dry powder dispenser has a base member which supports a blister pack of rupturable pillows each containing measured quantities of dry powder to be dispensed. A pillow aligning with the discharge opening and the base member which likewise has a discharge passage in communication therewith for the discharge of the dry powder as the pillow is ruptured by a hinged lever which displaces the entire contents of the dry powder from its pillow chamber into the discharge passage, the lever sequentially activating an air piston for flow feeding a quantity of pressurized air along the discharge passage to expel the dry powder under air pressure.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a hand-held dry powder dispenser, and more particularly to such a dispenser which can accommodate a blister pack of several rupturable pillows containing dry powder to be dispensed for personal care use. 
     Dry powder dispensers are available for use in expelling especially pharmaceutical media to the respiratory tract, such as through the nose and throat. Some powder dispensers are adapted for a blister pack containing a plurality of metered power packets to be dispensed from rupturable pillows or compartments. A moveable spike or anvil is provided for rupturing the pillow upon manual movement of one section of the dispenser relative to another, whereupon the powder media is free to be expelled through a discharge path of the dispenser. 
     A known dispenser of the type characterized above is disclosed in U.S. Pat. No. 6,179,164 to Karl-Heinz Fuchs. There the powder dispenser comprises moveable and stationary parts relatively moveable along a central axis. This stationary part supports a blister pack containing powder filled blisters or pillows in a circular array, and the moveable part has a spike and a coaxial discharge nozzle such that upon rotary shifting movement of one of the pillows in alignment with the spike end, inward shifting movement of the manual part ruptures the pillow and exposes the powder to the discharge nozzle. The moveable and stationary parts together include air piston and cylinder units, such that upon relative movement of the parts together air under pressure is forced through a one-way valve in the stationary part for directing the pressurized air to the exposed powder causing it to be expelled out through the nozzle discharge. 
     The prior art powder dispenser as aforedescribed is not without its drawbacks. For example, the air piston stroke is limited by the maximum spacing between the stationary and moveable parts, and the path of movement of the compressed air before it reaches the exposed powder is quite circuitous. For example, the path of the air is first axial, then outwardly radial and then again axial requiring an abrupt 90° turn. Because of the short stroke and the circuitous nature of the air path, air under sufficient pressure is unavailable at each stroke for adequately and completely expelling the loose powder from the discharge nozzle. Besides, since only a foil backing of the pillow is ruptured for freeing the powder contents of the pillow, the likelihood of completely expelling the powder from its opened pillow by the movement of a circuitous and short stroke air path, is limited. 
     There is need to improve upon the known dry powder dispensers to ensure that the entirety of the measured media is expelled from the ruptured capsule in a manner which is efficient, effective, and economical. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a dry powder dispenser of the type which accommodates a blister pack supporting measured quantities of a plurality of powder media, the blisters being ruptured one-at-a-time by a moving anvil with the freed powder media being forced out through the discharge by a burst of air under pressure. 
     To this end the dry powder dispenser according to the invention assures expelling of the entire contents of each of the capsules of the blister pack on incremental rupture thereof. The dispenser is structured such that the blister is completely emptied of its powder contents upon rupture by the anvil as the contents drop under gravity into a discharge passage at which time a puff of compressed air discharges the powder from the dispenser. 
     The dry powder dispenser of the invention includes a base supporting at least one medium reservoir having an hermetically sealed and openable dry powder containing chamber which aligns with the discharge opening in the base. A discharge passage in the base communicates with the discharge opening, and means are provided in the base for flow feeding a quantity of pressurized air along the discharge passage. A hinged lever on the base displaces the dry powder from its chamber, upon actuation thereof which sequentially activates the air feeding means. 
    
    
     Another objects, advantages, and novel features of the invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view, shown largely in section, of the powder dispenser according to the invention at a position with the air piston charged for firing; 
     FIG. 2 is a view similar to FIG. 1 showing the dispenser when activated for discharge of the powder; 
     FIG. 3 is a plan view taken substantially along the line  3 — 3  of FIG. 1 of means for rotating the blister pack; 
     FIG. 4 is sectional view taken substantially along the line  4 — 4  of FIG. 2; 
     FIG. 5 is a view taken substantially along the line  5 — 5  of FIG. 1; 
     FIG. 6 is an enlarged side view, partially in section, of the cocked piston stem; and 
     FIG. 7 is a side elevational view taken substantially along the line  7 — 7  of FIG.  6 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Turning now to the drawings wherein like reference characters refer to like and corresponding parts throughout the several views, the dispenser according to the invention is generally designated  10  in FIGS. 1 and 2 and includes a base member  11  which may be of a suitable molded plastic material of a relatively small size readily adaptable to be cradled in a hand of the operator. The base member supports a turntable  12  which may be of circular configuration on which rests an assembly  13  of a plurality of rupturable capsules or pillows  14  each containing a measured quantity of powder media of some specific type usable for especially nasal and throat applications. Typically the chamber formed by the pillow containing the powder is closed by a tearable foil  15  or the like (see FIG.  2 ), such that assembly  13  may be in the form of the well-known blister pack. As more clearly shown in FIG. 5, turntable  12  engages a splined post  16  mounted for free rotation on a forked arm  17  of the base member. The turntable has a plurality of openings  18  arranged in a circular array (FIG. 5) at which each of the pillows  14  is located. The turntable further has openings  19  likewise arranged in a circular array through which a firing pin  21  extends in a manner and for the purpose as described in detailed hereinafter. 
     The base member of the dispenser has an elongated discharge barrel  22  defining a discharge passage  23  through which a metered amount of product is discharged under the assistance of a puff of air according to the invention. At the root or inner end of the discharge barrel is a discharge opening  24  in open communication with passage  23  and in axial alignment with one of the openings  18  of the turntable. 
     The base member has a cylindrical shaped portion  25  (FIG. 4) defining a pump cylinder having a pump bore  26 . within which an air piston  27  operates. The air piston has a piston cup  28  in sliding sealing engagement with cylindrical bore  26 , and a piston stem  29  having a caged terminal end  31 . 
     The air piston is designed to be cocked in readiness to be “fired” by firing pin  21  during operation of the dispenser. The piston stem has a piston catch  32  which may be in the form of a depending triangular element shown in FIGS. 1,  2 ,  6  and  7 . Piston  27  is retracted to its firing position of FIG. 1 by manually pulling knob  33  in a direction shown by arrow  36  away from the base member, the knob having a stem  34  terminating in a boss  35  engaging an inner wall of cage  31 . When the knob is pulled in the direction of arrow  36  against the bias of its spring  37 , boss  35  causes the air piston to be shifted into its firing position of FIG. 1 against the bias of its spring  38 . 
     A firing yoke  39  is mounted within the base member for sliding movement between pairs of guide plates  41 , and is supported in its position of FIGS. 6,  7  by a compression spring  42 . The firing yoke has an oversized opening  43  through which piston stem  29  extends such that when the knob is pulled outwardly causing the piston to shift in the direction of arrow  36 , the piston catch  32  slides through opening  43  and in the process depresses yoke  39  against its spring  42  permitting the catch to clear opening  43  so as to come to rest in its FIGS. 1 and 6 position where radial face  44  of the catch bears against a confronting face of yoke  39 . When the operator releases knob  33  it shifts to its position shown in phantom outline in FIG. 1 under the assistance of its spring  37 . 
     A dispensing actuator is provided in the form of a lever arm  45  hinged to the base member as at  46 , the firing pin  21  depending from the arm and in alignment with firing yoke  39 . The lever arm also has a depending anvil  47  which may have a blunt end as shown or which may have a pointed end, the anvil being in alignment with discharge opening  24 . Thus, when the dispenser is placed in the firing position of FIG. 1, movement by the operator of lever arm  45  toward the base member about hinge  46  functions to rupture one of the pillows or capsules  14  in alignment with opening  24  which, as shown in FIG. 2, causes the entirety of the contents of the ruptured pillow to fall by gravity and displacement into discharge passage  23 . Sequentially with the rupturing of the blister, firing pin  21  engages yoke  39  causing it to shift downwardly against its spring  42 , permitting catch  32  to clear opening  43  and permitting the air piston to shift forwardly in the direction of arrow  48 . Thus air that was entrained in bore  26  is forced under pressure by the piston through reduced opening  49  causing the air to enter passage  23  under pressure for simultaneously producing an air burst causing the powder in the discharge passage to be expelled therefrom through terminal discharge orifice  51 . 
     This base member further has an indexing arm  52  having ratchet teeth  53  on its inner edge (FIG. 3) which engages splined post  16  while the piston is shifted from its FIG. 2 back to its FIG. 1 firing position. This engagement causes rotation of post  16  in the direction of the curved arrow shown for correspondingly rotating turntable  12  and with it the blister pack  13 . The degree of rotation of post  16  is set so as to index a single pillow  14  into and out of alignment with discharge opening  24 . Thus, each time the knob  33  is pulled outwardly to charge the piston, the blister pack is rotated for indexing the next powder filled pillow into alignment with anvil  47 . When the lever arm is lowered and the firing pin  21  trips the yoke to permit the piston to shift forwardly, arm  52  is made to disengage from post  16  in any normal manner known in this art, and to re-engage with the splines of the post prior to the arm being again shifted back into its FIG. 1 position. Such technology is known and forms no part of the invention. 
     The dry powder dispenser according to the invention as aforedescribed is of simple construction which is easy to fabricate, yet is highly efficient in expelling the entire contents of the rupturable pouch of a blister pack into, for example, the respiratory duct of the user. Few parts are required to fabricate the dispenser which is easy to use with little instructions. For example, the operator simply lifts lever  45  pivoting it about its hinge  46  and places a circular blister pack  13  onto the top surface of turntable  12 , post  16  extending through a central opening in the pack. The dry powder filled pillows  14  are respectively aligned with their openings  18  in the turntable by the provision of some type of orienting means acting between assembly  13  and turntable  12 , such as, for example, a key and a keyway. Also it should be pointed out that a hinged lid (not shown) may be provided as hinged to base member  11  covering the circular blister pack, the hinge being clasped in place in some manner to base member  11 . A nasal adaptor hood (not shown) which may be provided to cover the discharge barrel  22  for sanitary purposes, would then be removed, and the operator thereafter pulls outwardly on knob  33  which charges the air piston and places it in the “firing” position of FIG.  1 . The operator then expels the contents of one of the pillows  14  into his nose or throat or whatever, by simply depressing lever  45  to the FIG. 2 position. When the lever is lowered about its hinge  46  to the FIG. 2 position, handle  47  ruptures pillow  14  thereby emptying the powder contents into discharge passage  23  as the entirety of the contents fall by gravity and displacement into this passage. Sequentially therewith, firing pin  21  depresses yoke  39  shifting it downwardly against the force of its spring  42  and permitting catch  32  to pass forwardly in the direction of arrow  48  through opening  43  which thereby releases the piston causing the piston head to force air from air chamber  26  under pressure through constricted opening  49  into discharge passage  23 . This forced air provides a burst of air to the fallen dry powder and expels it completely and neatly out of the discharge end  51  of the nozzle. For subsequent usage, the operator again pulls knob  33  outwardly in the direction of arrow  36  which again places the air piston into its firing position of FIG.  1  and which simultaneously indexes the next pillow  14  into alignment with opening  24  as indexing arm  52  rotates splined post  16  in the direction of the curved arrow as shown. This subsequent dispensing is carried out as aforedescribed. 
     Obviously, many modifications and variations of the present invention are made possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.