Liquid Dispensing Syringe

Abstract

A syringe for dispensing liquid materials to a substrate. In one embodiment, the syringe includes a barrel having a first end, a second end, and an interior reservoir. A piston is slidably disposed within the reservoir and is movable to increase or decrease a volume of the interior reservoir near the first end of the barrel. At least a portion of at least one of the barrel, the piston, or the dispensing tip comprises a material selected to maintain operative structural integrity of the dispensing syringe at elevated temperatures.

What is claimed is: 
     
         1 . A dispensing syringe, comprising:
 a barrel having a first end and a second end, and defining an interior reservoir therein;   a dispensing tip proximate said first end of said barrel, said dispensing tip including an outlet in fluid communication with said reservoir;   wherein at least a portion of at least one of said barrel or said dispensing tip comprises a material selected to maintain operative structural integrity of the dispensing syringe at temperatures above about 150 degrees Celsius.   
     
     
         2 . The dispensing syringe of  claim 1 , wherein said material comprises a high temperature resin. 
     
     
         3 . The dispensing syringe of  claim 2 , wherein said material comprises polybutylene terephthalate. 
     
     
         4 . The dispensing syringe of  claim 2 , wherein said material is a composite material that further comprises fiber reinforcement. 
     
     
         5 . The dispensing syringe of  claim 1 , further comprising:
 an adapter selectively removably coupled to said second end of said barrel for coupling said barrel to a source of pressurized fluid.   
     
     
         6 . The dispensing syringe of  claim 1 , further comprising:
 a piston slidably disposed within said interior reservoir.   
     
     
         7 . The dispensing syringe of  claim 6 , wherein the piston comprises polybutylene terephthalate. 
     
     
         8 . The dispensing syringe of  claim 6  further comprising a hot melt adhesive disposed in the interior reservoir. 
     
     
         9 . A dispensing syringe, comprising:
 a barrel having a first end and a second end, and defining an interior reservoir therein;   a piston slidably disposed within said reservoir to thereby increase or decrease a volume of said interior reservoir proximate said first end of said barrel;   said piston having a first end and a second end, said first end having a generally hemispherically-shaped surface profile with an elongated apex extending along a central axis thereof for dispensing fluid from said first end of said barrel when said piston is moved toward said first end of said barrel; and   a luer coupling at said first end of said barrel adapted for receiving a dispensing tip;   said luer coupling including an outlet orifice and an outlet passage in fluid communication between said outlet orifice and said reservoir;   said outlet passage tapered along an axial length thereof;   wherein at least a portion of at least one of said barrel, said piston, or said luer coupling comprises a material selected to maintain operative structural integrity of the dispensing syringe at temperatures above about 150 degrees Celsius.   
     
     
         10 . The dispensing syringe of  claim 9 , wherein said material comprises a high temperature resin. 
     
     
         11 . The dispensing syringe of  claim 10 , wherein said material comprises polybutylene terephthalate. 
     
     
         12 . The dispensing syringe of  claim 10 , wherein said material is a composite material that further comprises fiber reinforcement. 
     
     
         13 . The dispensing syringe of  claim 9 , further comprising:
 an adapter selectively removably coupled to said second end of said barrel for coupling said barrel to a source of pressurized fluid.   
     
     
         14 . The dispensing syringe of  claim 9 , further comprising:
 an end cap selectively removably coupled to said second end of said barrel for sealing said barrel.   
     
     
         15 . The dispensing syringe of  claim 9 , further comprising:
 a tip cap selectively removably coupled to said luer coupling at said first end of said barrel and sealingly engaging said outlet orifice of said luer coupling when said tip cap is firmly seated on said luer coupling.   
     
     
         16 . The dispensing syringe of  claim 9 , wherein said barrel further comprises:
 an elongate tubular body including at least one sidewall defining said interior reservoir;   said sidewall further defining a hemispherically-shaped portion within said interior reservoir proximate said first end of said body and complementary to said hemispherically-shaped surface profile of said piston.   
     
     
         17 . The dispensing syringe of  claim 16 , wherein said barrel further comprises:
 a radially inwardly extending ledge within said interior reservoir adjacent said hemispherically-shaped portion, said sidewall having a substantially uniform thickness proximate said ledge, whereby the location of said radially inwardly extending ledge is visible externally of said body by a corresponding radially outwardly extending ledge.   
     
     
         18 . The dispensing syringe of  claim 9 , further comprising a hot melt adhesive disposed in said interior reservoir. 
     
     
         19 . A method of dispensing a hot melt adhesive, comprising:
 heating a dispensing syringe to liquefy hot melt adhesive disposed within an interior reservoir of the dispensing syringe, the dispensing syringe comprising:
 a barrel having a first end and a second end and defining the interior reservoir therein, 
 a dispensing tip proximate the first end of the barrel, 
 an outlet in fluid communication with the interior reservoir, and 
 a piston slidably disposed within the interior reservoir, 
 wherein at least a portion of at least one of the barrel or the dispensing tip comprises a material selected to maintain operative structural integrity of the dispensing syringe at temperatures above about 150 degrees Celsius; and 
   moving the piston in a direction toward the dispensing tip to dispense the hot melt adhesive from the outlet.   
     
     
         20 . The method of  claim 19 , wherein the dispensing syringe further comprises:
 a luer coupling at the first end of the barrel and adapted for receiving the dispensing tip, the luer coupling including an outlet orifice and an outlet passage in fluid communication between the outlet orifice and the reservoir, the outlet passage tapered along an axial length thereof;   wherein the piston has a first end and a second end, the first end having a generally hemispherically-shaped surface profile with an elongated apex extending along a central axis thereof for dispensing fluid from the first end of the barrel when the piston is moved toward the first end of said barrel; and   wherein at least a portion of at least one of the barrel, the piston, or the luer coupling comprises a material selected to maintain operative structural integrity of the dispensing syringe at temperatures above about 150 degrees Celsius.