Needle valve actuator for hot melt adhesive hand applicator and a method for operating the same

摘要

A hot melt adhesive dispensing gun has a needle valve movably mounted within a dispensing nozzle provided with a discharge port from which hot melt adhesive material can be dispensed, wherein the needle valve is normally seated upon a valve seat. An electrical switch mechanism is mounted upon the dispensing gun for controlling the activation of an adhesive material supply pump as well as a solenoid air valve for controlling the supply of swirl air in conjunction with the supply and dispensing of the hot melt adhesive material. A trigger member is operatively connected to the electrical switch mechanism and the needle valve such that when the trigger member is actuated or squeezed, the electrical switch mechanism is CLOSED prior to the unseating of the valve member from its valve seat so as to ensure a sufficient supply of hot melt adhesive material and swirl air to the dispensing nozzle prior to the actual dispensing of the hot melt adhesive material from the discharge port.