| 摘要 |
A needle valve nozzle is employed in a hot melt adhesive gun used to apply thermoplastic adhesive. Actuation of a trigger mechanism supplies pressurized gas to a nozzle chamber which urges the nozzle in an outward direction to an open position, the needle remaining stationary during operation of the nozzle. Deactuation of the trigger mechanism stops the flow of pressurized gas to the chamber and a vent allows the pressurized gas to flow from the chamber, permitting a spring-biasing mechanism to return the nozzle to a closed position. Pressure on the adhesive can also be employed to urge the nozzle to an open position. |
