Patent ID: 7900800

Claim:
An apparatus for dispensing a viscous material, comprising: an upper body; a needle valve mounted for reciprocating movement in said upper body, said needle valve having a vertical orientation; an actuator operatively coupled to said needle valve for reciprocating said needle valve; a heat exchanger including a heater, a vertically disposed fluid inlet, a fluid outlet, a serpentine path extending horizontally between said fluid inlet and said fluid outlet, and a vertically disposed bore laterally offset from said vertically disposed fluid inlet, said fluid outlet being disposed in a side wall of the bore, said upper body being assembled to said heat exchanger with said needle valve extending through said bore; a vertically disposed reservoir for the viscous material; a coupling connecting said reservoir to said heat exchanger to place said reservoir in fluid communication with said fluid inlet of said heat exchanger with said reservoir being laterally offset from said needle valve; a lower body, said lower body being assembled to said heat exchanger with said needle valve extending through said lower body, said lower body including a fluid chamber, said fluid outlet of said heat exchanger being in fluid communication with said fluid chamber; and a nozzle assembly coupled to said lower body, said nozzle assembly including a valve seat, and a discharge path connecting said valve seat to a discharge orifice, said needle valve extending through said nozzle assembly and being engageable with said valve seat, said discharge path being in fluid communication with said fluid chamber, wherein viscous material flows from said reservoir, through said serpentine path of said heat exchanger into said fluid chamber, and then from said fluid chamber through said discharge path and said discharge orifice, the material being heated while passing through said serpentine path, and wherein said needle valve is reciprocated by said actuator between an open position in which said needle valve is disengaged from said valve seat to allow material to flow through said discharge orifice, and a closed position in which said needle valve is engaged with said valve seat to prevent material flow from said discharge orifice.