Liquid Dispensing System

Abstract

A liquid dispensing system comprises a cartridge ( 2 ) in which liquid to be dispensed is retained and at least one solenoid assembly. The solenoid assembly comprises a coil ( 15 ) and an armature ( 3 ), the armature ( 3 ) being movably mounted within the cartridge ( 2 ) and the coil ( 15 ) being separate from the cartridge ( 2 ). Movement of the armature ( 3 ) acts to expel liquid from the cartridge ( 2 ).

1 . A liquid dispensing system comprising a cartridge ( 2 ) in which liquid to be dispensed is retained and at least one solenoid assembly, the solenoid assembly comprising a coil ( 15 ) and an armature ( 3 ), the armature ( 3 ) being movably mounted within the cartridge ( 2 ) and the coil ( 15 ) being separate from the cartridge ( 2 ), movement of the armature ( 3 ) acting to expel liquid from the cartridge ( 2 ). 
     
     
         2 . A liquid dispensing system according to  claim 1 , in which the cartridge ( 2 ) is disposable. 
     
     
         3 . A liquid dispensing system according to  claim 1 , in which the cartridge ( 2 ), when assembled, comprises a cartridge body ( 5 ), the armature ( 3 ), a return spring ( 14 ) for the armature ( 3 ) and a nozzle assembly ( 4 ). 
     
     
         4 . A liquid dispensing system according to  claim 3 , in which the armature ( 3 ) is biased by the return spring ( 14 ) towards a first position, and towards a second position by activation of the coil ( 15 ). 
     
     
         5 . A liquid dispensing system according to  claim 1 , in which the armature ( 3 ) slides within the cartridge ( 2 ). 
     
     
         6 . A liquid dispensing system according to  claim 4 , in which in the first position the armature ( 3 ) closes off flow through the nozzle assembly ( 4 ). 
     
     
         7 . A liquid dispensing system according to  claim 6 , in which activation of the coil ( 15 ) moves the armature ( 3 ) to allow flow through the nozzle assembly ( 4 ), and movement of the armature in response to the return spring ( 14 ) dispenses the liquid. 
     
     
         8 . A liquid dispensing system according to  claim 3 , in which the return spring ( 14 ) is a separate component from the cartridge ( 2 ), armature ( 3 ) and nozzle assembly ( 4 ). 
     
     
         9 . A liquid dispensing system according to  claim 4 , in which in the first position the armature ( 3 ) allows flow through the nozzle assembly ( 4 ). 
     
     
         10 . A liquid dispensing system according to  claim 9 , in which activation of the coil ( 15 ) moves the armature ( 3 ) to dispense the liquid. 
     
     
         11 . A liquid dispensing system according to  claim 3 , in which the return spring ( 14 ) is formed integrally with the nozzle assembly ( 4 ). 
     
     
         12 . A liquid dispensing system according to  claim 1 , in which the armature ( 3 ) comprises iron or other magnetic material. 
     
     
         13 . A liquid dispensing system according to  claim 1 , in which the cartridge ( 2 ) is disposed within the coil ( 15 ) when the cartridge ( 2 ) is mounted in the dispensing system ( 1 ). 
     
     
         14 . A liquid dispensing system according to  claim 1 , in which the cartridge ( 2 ) has two chambers, of which the first chamber ( 6 ) is a reservoir for the liquid and the second chamber ( 7 ) retains the armature ( 3 ). 
     
     
         15 . A liquid dispensing system according to  claim 14 , in which the second chamber ( 7 ) is disposed within the coil ( 15 ) when the cartridge ( 2 ) is mounted in the dispensing system ( 1 ). 
     
     
         16 . A liquid dispensing system according to  claim 14 , in which the armature ( 3 ) defines a dispensing chamber ( 32 ) in the second chamber ( 7 ) in which the liquid to be dispensed collects. 
     
     
         17 . A liquid dispensing system according to  claim 16 , in which the armature ( 3 ) has a fluid flow path ( 26 ) for transferring fluid from the reservoir ( 6 ) to the dispensing chamber ( 32 ). 
     
     
         18 . A liquid dispensing system according to  claim 17 , in which the fluid flow path ( 26 ) comprises a bore through the armature ( 3 ). 
     
     
         19 . A liquid dispensing system according to  claim 17 , in which the fluid flow path ( 26 ) comprises an annular groove in the outer surface of the armature ( 3 ). 
     
     
         20 . A liquid dispensing system according to  claim 16 , in which axial movement of the armature ( 3 ) in one direction dispenses the liquid and in the other direction, pumps liquid from the reservoir ( 6 ) into dispensing chamber ( 32 ). 
     
     
         21 . A liquid dispensing system according to  claim 3 , in which the nozzle assembly ( 4 ) includes a one-way valve. 
     
     
         22 . A liquid dispensing system according to  claim 21 , in which the one-way valve is a “duck-bill” valve ( 33 ). 
     
     
         23 . A liquid dispensing system according to  claim 1 , in which the dispensing system ( 1 ) includes one solenoid coil ( 15 ). 
     
     
         24 . A liquid dispensing system according to  claim 1 , in which the dispensing system ( 1 ) includes two solenoid coils ( 15 ,  58 ). 
     
     
         25 . A liquid dispensing system according to  claim 24 , in which the cartridge ( 2 ) contains two armatures ( 3 ,  61 ) and two dispensing chambers ( 32 ,  64 ). 
     
     
         26 . A liquid dispensing system according to  claim 14 , in which reservoir ( 6 ) has a pressure/vacuum source ( 30 ) attached thereto. 
     
     
         27 . A liquid dispensing system according to  claim 1 , in which the cartridge ( 2 ) includes a lid ( 24 ) having a moulded hinge. 
     
     
         28 . A liquid dispensing system according to  claim 3 , in which the nozzle assembly ( 4 ) is mounted with the cartridge ( 2 ) by interference fit. 
     
     
         29 . A liquid dispensing system according to  claim 3 , in which the nozzle assembly ( 4 ) is mounted with the cartridge ( 2 ) with adhesive. 
     
     
         30 . A liquid dispensing system according to  claim 3 , in which the nozzle assembly ( 4 ) is integrally moulded with the cartridge ( 2 ). 
     
     
         31 . A liquid dispensing system according to  claim 3 , in which the nozzle assembly ( 4 ) has a nozzle ( 12 ) and a shroud ( 13 ). 
     
     
         32 . A liquid dispensing system according to  claim 31 , in which the nozzle ( 12 ) has a hydrophobic coating to aid complete expulsion of liquid therefrom. 
     
     
         33 . A liquid dispensing system according to  claim 16 , in which dispensing chamber ( 32 ) has a hydrophobic coating to aid complete expulsion of liquid therefrom. 
     
     
         34 . A liquid dispensing system according to  claim 1 , adapted to dispense quantities of liquid in the order of microlitres.