Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B11/00—Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use
  • B05B11/01—Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use characterised by the means producing the flow
  • B05B11/10—Pump arrangements for transferring the contents from the container to a pump chamber by a sucking effect and forcing the contents out through the dispensing nozzle
  • B05B11/1042—Components or details
  • B05B11/1066—Pump inlet valves
  • B05B11/107—Gate valves; Sliding valves
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B11/00—Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use
  • B05B11/01—Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use characterised by the means producing the flow
  • B05B11/10—Pump arrangements for transferring the contents from the container to a pump chamber by a sucking effect and forcing the contents out through the dispensing nozzle
  • B05B11/1001—Piston pumps
  • B05B11/1023—Piston pumps having an outlet valve opened by deformation or displacement of the piston relative to its actuating stem
  • B05B11/1025—Piston pumps having an outlet valve opened by deformation or displacement of the piston relative to its actuating stem a spring urging the outlet valve in its closed position
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B11/00—Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use
  • B05B11/01—Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use characterised by the means producing the flow
  • B05B11/10—Pump arrangements for transferring the contents from the container to a pump chamber by a sucking effect and forcing the contents out through the dispensing nozzle
  • B05B11/1038—Pressure accumulation pumps, i.e. pumps comprising a pressure accumulation chamber
  • B05B11/104—Pressure accumulation pumps, i.e. pumps comprising a pressure accumulation chamber the outlet valve being opened by pressure after a defined accumulation stroke

Definitions

• the present invention relates to a dispensing apparatus particularly a multi- dose dispensing apparatus for dispensing metered quantities of fluid.
• Conventional multi-dose dispensers have a metering chamber with a piston arranged therein.
• the metering chamber draws the fluid to be dispensed from a reservoir through a dip tube.
• the dip tube is connected to the base of the metering chamber via a one-way valve.
• the piston is depressed axially within the metering chamber to force the fluid from the chamber through an outlet.
• the one-way valve which usually comprises a ball or rubber flap, seals the passage from the metering chamber to the dip tube.
• the piston After the fluid has been dispensed, the piston is released and returns to its original rest position drawing more fluid from the reservoir, up the dip tube, through the one-way valve in the base of the metering chamber and into the metering chamber as it rises.
• the one-way valves are known to be inefficient and contribute to variations in the shot weight dispensed.
• the shot weight dispensed by different dispensers is found to vary due to the tolerance stack-up of a number of mass- produced components which cause differences in the rest position of the pistons. It is an object of the present invention to reduce variations in the shot weight of a multi-dose dispenser.
• a hand-held multi-dose dispensing apparatus comprising a metering chamber having an axis, an end portion at one axial end of the chamber and a side body portion extending from the axial end portion, a piston arrangement movable with a piston stroke along the axis of the metering chamber with a seal portion of the piston arrangement being slidably engageable with a side portion of the metering chamber, an inlet for fluid to enter the metering chamber, and an outlet for fluid to be dispensed from the metering chamber, wherein the inlet is provided on the side body portion of the metering chamber and, in use, during a first portion of the piston stroke the inlet is in fluid communication with the metering chamber and during a second portion of the piston stroke the seal portion of the piston arrangement blocks the inlet preventing fluid from passing from the inlet into or out of the metering chamber.
• the positioning of the inlet on the side portion of the metering chamber and the action of the piston to respectively provide fluid communication and block the inlet to the metering chamber during first and second portions of the piston stroke eliminates the need for a one-way valve, reducing costs and increasing reliability of the dispenser. Furthermore, since the volume of fluid dispensed is determined by the point at which the piston enters the second portion of it's stroke as it blocks off the inlet and prevents further fluid from entering the metering chamber, a more consistent volume of fluid is dispensed. This eliminates variations produced by tolerance stack-up of dispenser components causing the rest position of the piston and thus the shot weight to var - between dispensers.
• a resilient member is preferably provided between the end portion of the metering chamber and the piston.
• the resilient member urges the piston into a rest position at the furthest point in its stroke from the end portion of the metering chamber.
• the resilient member may be an elastic member or a spring for example.
• the piston arrangement preferably comprises a first portion and a piston seal, the piston seal being arranged to slidably engage and seal against the inside surface of the metering chamber and to be moveable relative to the first portion of the piston arrangement, such that during a second portion of the piston stroke when the pressure in the metering chamber exceeds a particular level, the first portion and the piston seal move relative to each other to open an outlet for fluid to be dispensed.
• Figure 1 shows a cross-sectional view of a dispensing apparatus with the piston in the rest position
• Figure 2 shows the cross-sectional view of the dispensing apparatus of Figure 1 with a piston arrangement blocking an inlet
• Figure 3 shows the cross-sectional view of the dispensing apparatus of Figure 1 with the piston arrangement in the bottomed out position.
• Figure 1 shows a cross-sectional view of a dispensing apparatus 10 prior to actuation.
• the dispensing apparatus 10 has a metering chamber 20 with an axis 21, an end portion 22 at one end and a side body portion 23 extending therefrom surrounding the metermg chamber 20.
• the side body portion 23 has a narrower section 24 adjacent the end portion 22 then a frusto-conical portion 25 leading to a wider section 26.
• the metering chamber could be any desired shape such as cylindrical for example.
• the side body portion 23 has an inlet 27 formed therein. In use, the inlet 27 is connected via collar 28 to a dip tube to draw fluid to be dispensed from a reservoir (not shown).
• the reservoir could be any suitable container which is preferably, but need not be attached to the dispensing apparatus 10.
• a piston arrangement 30 is provided inside the metering chamber 20.
• the piston arrangement comprises an insert rod 31 with an annular core 32 slid over a portion of its length.
• the core 32 rests on a first annular seat 33 extending out from the insert rod 31.
• the piston arrangement also has a piston seal 34 slid over the core 32.
• An outer surface of the piston seal 34 slidably engages and seals against the inside surface of the side body portion 23 of the metering chamber 20.
• the piston seal 34 rests on a second annular seat 35 which, like the first annular seat 33, also extends out from insert rod 31.
• a resilient member, in this example a spring 36 is provided between an annular seat 37 on the core 32 and the piston seal 34 to urge the piston seal 34 on to the annular seat 35 on the insert rod 31.
• a further resilient member in this example another spring 38, is provided between the end portion 22 of the metering chamber and an annular seat 39 on the underside of insert rod 31 to urge the piston arrangement 30 into the rest position shown in figure 1 with an annular projection 40 of the core 32 engaging a cap 50 provided on the metering chamber 20.
• An upper section of the core 32 extends through a circular aperture 51 provided in the cap 50.
• An appropriate actuator (not shown) is attached to the upper section of the core which extends through the aperture 51 provided in the cap 50.
• the actuator will be adapted for the application to which the dispensing apparatus is to be put, such as a nasal dispenser or oral dispenser for example.
• a ferrule 60 is provided attached to the cap 50.
• FIG. 2 shows the dispensing apparatus 10 beginning to be actuated with, the upper section of the core 32 which extends out through the cap 50 being manually depressed by a user to push it towards the end portion 22 of the metering chamber 20.
• the annular projection 40 disengages the cap 50 and the piston seal 34 slides downwards over the inside surface of the metering chamber to block the inlet 27 preventing further fluid from entering the metering chamber 20.
• the pressure within the metering chamber 20 which causes the piston seal 34 to unseat relative to the insert rod 31 is set at a predetermined level by selection of a suitable spring 36.
• the piston seal 34 can be arranged to unseat relative to the insert rod 31 at any desired pressure within the metering chamber 20. Fluid from the metering chamber 20 is forced through openings (not shown) exposed in the lower portion of the core 32 by the unseating of the seal 34 from the insert rod 31 and up through the core 32 to an outlet in the actuator. Fluid continues to be dispensed as the core 32 is manually pressed further into the metering chamber 20 until the piston arrangement bottoms out.
• the dispensing apparatus could be used to dispense any suitable fluid.
• the fluid is preferably a pharmaceutical product and may include, for example, a pure drug or a drug with a liquid and/or pharmaceutical acceptable excipient.
• the metering chamber 20 could be any suitable shape.
• fluid could be passed out of the metering chamber through any suitable outlet.
• the dispensing apparatus is preferably made from a plastics material but could be made from any suitable material.
• any closure system could be used to attach the dispensing apparatus to a container of fluid to be dispensed such as a screw-on or snap closure.

Landscapes

• Containers And Packaging Bodies Having A Special Means To Remove Contents (AREA)
• Infusion, Injection, And Reservoir Apparatuses (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=29287036

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (34)

Family Cites Families (10)

• 2003
  • 2003-09-29 GB GB0322758A patent/GB2406330B/en not_active Expired - Fee Related
• 2004
  • 2004-09-06 WO PCT/GB2004/003790 patent/WO2005030401A1/en active Application Filing
  • 2004-09-06 US US10/595,214 patent/US20090173752A1/en not_active Abandoned
  • 2004-09-06 EP EP04768337A patent/EP1667801B1/de not_active Expired - Lifetime
  • 2004-09-06 CN CNA2004800280562A patent/CN1859983A/zh active Pending
  • 2004-09-06 BR BRPI0414820-7A patent/BRPI0414820A/pt not_active IP Right Cessation
  • 2004-09-06 DE DE602004022685T patent/DE602004022685D1/de not_active Expired - Fee Related

Non-Patent Citations (1)

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