Anti-drip anti-foaming fluid dispensing system

Abstract

A system for dispensing exact quantities of fluid into containers without dripping or foaming can be made from the combination of a controllable pump, a tube (preferably hydrophobic), and a nozzle usually made of elastomeric material with an orifice or slit such a duck bill valves commercially available. Forward pressure causes the slit to open, while elastic force causes it to close when pumping stops. An alternative embodiment is to use slits backed by small diameter screen to achieve a back pressure.

1 . A no-drip, anti-foaming fluid dispensing system comprising: 
 a fluid pump supplying a forward fluid pressure;    a delivery tube fluidly coupled to said pump for delivering said fluid into a fluid container;    an elastomeric tip on said delivery tube containing at least one exit orifice, said exit orifice expanding in response to said forward fluid pressure and contracting when said forward fluid pressure is removed.    
   
   
       2 . The fluid dispensing system of  claim 1  wherein said fluid pump is a positive displacement linear pump.  
   
   
       3 . The fluid dispensing system of  claim 1  wherein said fluid pump is a peristaltic pump.  
   
   
       4 . The fluid dispensing system of  claim 1  wherein said elastomeric tip is a duck bill valve.  
   
   
       5 . The fluid dispensing system of  claim 1  wherein said elastomeric tip has a plurality of orifices.  
   
   
       6 . The fluid dispensing system of  claim 1  further comprising said pump also supplying back pressure after a predetermined quantity of said fluid is dispensed.  
   
   
       7 . The fluid dispensing system of  claim 4  wherein said duck bill valve is silicone.  
   
   
       8 . The fluid dispensing system of  claim 1  wherein said delivery tube is a hydrophobic material.  
   
   
       9 . A no-drip, anti-foaming fluid dispensing system comprising: 
 a fluid pump supplying a forward fluid pressure;    a coupling tube fluidly coupled to said pump for delivering said fluid into a fluid container;    a dispensing tip on said coupling tube containing at least one exit orifice;    a screen covering said exit orifice, said polymer screen preventing drip through when said forward fluid pressure is removed.    
   
   
       10 . The fluid dispensing system of  claim 9  wherein said exit orifice is elongated along the axis of said coupling tube.  
   
   
       11 . The fluid dispensing system of  claim 9  further comprising a second screen covering said exit orifice.  
   
   
       12 . The fluid dispensing system of  claim 9  wherein said screen is a polymer.  
   
   
       13 . The fluid dispensing system of  claim 9  wherein said pump is a positive displacement linear pump.  
   
   
       14 . The fluid dispensing system of  claim 9  wherein said pump is a peristaltic pump.  
   
   
       15 . A method of dispensing a predetermined quantity of fluid into a container without drip or foaming comprising the steps of: 
 causing a fluid pump to move said predetermined quantity of fluid from a reservoir into a delivery tube, said delivery tube having at least one exit orifice, said exit orifice containing a means for causing backpressure on said flow, wherein a forward pressure from said pump overcomes this backpressure to allow said predetermined quantity of fluid to exit said orifice;    allowing said backpressure to keep any remaining fluid in said tube after said predetermined quantity of fluid has been dispensed.    
   
   
       16 . The method of  claim 15  wherein said means for causing backpressure is a duck bill valve.  
   
   
       17 . The method of  claim 15  wherein said means for causing backpressure is a screen.  
   
   
       18 . The method of  claim 15  wherein said delivery tube is hydrophobic.  
   
   
       19 . The method of  claim 15  wherein said pump is a linear displacement piston driven pump.  
   
   
       20 . The method of  claim 15  wherein said pump is a peristaltic pump.