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

• Main Author: Donley, Paul J
• Format: Patent
• Language: English
• Published: 09.07.2002

The present invention relates generally to hot melt adhesive hand applicators or applicator guns, and more particularly to a new and improved hot melt adhesive hand applicator or applicator gun, and a method of operating the same, wherein the trigger mechanism thereof is interconnected to the needle valve member of the applicator or gun such that when the trigger mechanism of the applicator or gun is squeezed or pulled, a substantially two-part or two-step actuation-type mode of operation is effectively achieved whereby in accordance with a first part or first step of the actuation operation, an electrical switch is initially moved from its OPENED state to its CLOSED state so as to provide power to, for example, a rotary gear pump by means of which adhesive material may be supplied to the applicator or gun under pressure, and simultaneously therewith, electrical power is also provided to a solenoid air valve by means of which pressurized air can be supplied to the nozzle assembly of the applicator or gun in a swirl application mode for interaction with the adhesive material, while in accordance with a subsequent, second part or second step of the actuation operation, the needle valve member is moved axially so as to be effectively lifted from its CLOSED position upon its valve seat to an OPENED position away from the valve seat so as to permit the dispensing of the adhesive material. 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.