Liquid dosing devices

Abstract

A dosing device for dispensing liquid from a container ( 1 ) in which flow through flow openings ( 23 ) to an outlet tube ( 44 ) is blocked after controlled delay by an obturator ( 3 ) moveable within a control chamber ( 2 ) mounted in a container neck ( 101 ) behind the outlet tube ( 44 ). Movement of the obturator ( 3 ) is governed by restricted flow through control openings ( 28 ) at the rear of the control chamber. Restoration of the obturator to the back of the control chamber facilitates repeated dosing. An elastomeric element ( 6 ) of resiliently deformable material promotes a seal to achieve a cleanly defined dose. In one proposal the elastomeric element coats the surface of the obturator and/or the outlet tube ( 64 ) to cut off the flow. Another proposal provides a one-way elastomeric valve element ( 63 ) for blocking the flow openings to enable rapid recovery after a dosing operation.

1 . A dosing device for dispensing metered doses of liquid from a resiliently squeezable container, the dosing device comprising:
 a component defining a discharge opening, a control chamber and an obturator movable in the control chamber;   the dosing device defining an outlet passage for liquid from the container leading past or around the control chamber to the discharge opening;   the control chamber having one or more control openings to admit a restricted flow of liquid from the container interior into the control chamber;   the obturator being movable in the control chamber and adapted to advance during dispensing, under the influence of liquid flowing into the control chamber through the one or more control openings, to a blocking position where it blocks the outlet passage to terminate a dose; and   wherein the obturator is in the form of a control piston comprising a central disc and a set of axially-projecting guide lugs around the edge of the central disc, said guide lugs projecting axially further on one side of the disc than on the other side of the disc.   
     
     
         2 . The dosing device of  claim 1  wherein said outlet passage being defined by a tubular outlet formation having a surface which the obturator engages in said blocking position. 
     
     
         3 . The dosing device of  claim 2  wherein said component includes a structure which is constructed and arranged for assembly to said container. 
     
     
         4 . The dosing device of  claim 3  wherein said structure includes said discharge opening. 
     
     
         5 . The dosing device of  claim 1  wherein said component includes a structure which is constructed and arranged for assembly to said container. 
     
     
         6 . A dosing device for dispensing metered doses of liquid from a resiliently squeezable container, the dosing device comprising:
 a front component defining a front discharge opening, a control chamber and an obturator movable in the control chamber;   the dosing device defining an outlet passage for liquid from the container leading past or around the control chamber to the discharge opening;   the control chamber having one or more rear control openings to admit a restricted flow of liquid from the container interior into the control chamber, and   the obturator being movable in the control chamber and adapted to advance during dispensing, under the influence of liquid flowing into the control chamber through the one or more control openings, forwardly from a rear position to a blocking position where it blocks the outlet passage to terminate a dose;   wherein the obturator is in the form of a control piston comprising a central disc and a set of axially-projecting guide lugs around the edge of the central disc, said guide lugs projecting axially primarily on one side of the disc; and   the control chamber has a rear wall of which the inner surface is directed along the control chamber in the direction of movement of the obturator, a set of said control openings being distributed around said rear wall, and the obturator lying against the rear wall in the rear position thereof.   
     
     
         7 . The dosing device of  claim 6  wherein said outlet passage being defined by a tubular outlet formation having a surface which the obturator engages in said blocking position. 
     
     
         8 . The dosing device of  claim 7  wherein said component includes a structure which is constructed and arranged for assembly to said container. 
     
     
         9 . The dosing device of  claim 8  wherein said structure includes said discharge opening. 
     
     
         10 . The dosing device of  claim 6  wherein said component includes a structure which is constructed and arranged for assembly to said container. 
     
     
         11 . A dosing device for dispensing metered doses of liquid from a resiliently squeezable container, the dosing device comprising:
 a component defining a discharge opening, a control chamber and an obturator movable in the control chamber;   the dosing device defining an outlet passage for liquid from the container leading past or around the control chamber to the discharge opening;   the control chamber having one or more control openings to admit a restricted flow of liquid from the container interior into the control chamber;   the obturator being movable in the control chamber and adapted to advance during dispensing, under the influence of liquid flowing into the control chamber through the one or more control openings, to a blocking position where it blocks the outlet passage to terminate a dose; and   wherein said obturator is in the form of a flow-control piston including a flow-blocking panel, a first protruding portion extending in a first direction away from said flow-blocking panel and a second protruding portion extending in a second direction away from said flow-blocking panel, wherein said first direction is opposite to said second direction and said first projecting portion is axially longer than said second projecting portion.   
     
     
         12 . The dosing device of  claim 11  wherein said outlet passage being defined by a tubular outlet formation having a surface which the obturator engages in said blocking position. 
     
     
         13 . The dosing device of  claim 12  wherein said component includes a structure which is constructed and arranged for assembly to said container. 
     
     
         14 . The dosing device of  claim 13  wherein said structure includes said discharge opening. 
     
     
         15 . The dosing device of  claim 11  wherein said component includes a structure which is constructed and arranged for assembly to said container. 
     
     
         16 . A dosing device for dispensing metered doses of liquid from a resiliently squeezable container, the dosing device comprising:
 a component defining a discharge opening, a control chamber and an obturator movable in the control chamber;   the dosing device including an outlet tube having a lower edge and defining a passage for liquid from the container which has entered the control chamber to flow through to the discharge opening;   the control chamber including an opening to admit a flow of liquid from the container interior into the control chamber, said opening having a lower edge axially above the lower edge of said outlet tube; and   the obturator being movable in the control chamber and adapted to advance during dispensing, under the influence of liquid flowing into the control chamber through said opening, to a blocking position where it blocks the outlet passage to terminate a dose.   
     
     
         17 . The dosing device of  claim 16  wherein said obturator engages the lower edge of said outlet tube in said blocking position. 
     
     
         18 . The dosing device of  claim 17  wherein said component includes a structure which is constructed and arranged for assembly to said container. 
     
     
         19 . The dosing device of  claim 18  wherein said structure includes said discharge opening. 
     
     
         20 . The dosing device of  claim 16  wherein said component includes a structure which is constructed and arranged for assembly to said container.