Controllable spray nozzle assembly

摘要

A controllable spray nozzle assembly with an elongated discharge passageway is provided with a short discharge orifice and valve seat insert element that is made separately for ease and accuracy of providing its orifice and valve seat and is mounted in sliding sealing relation with the outlet end of the passageway. A valve needle extends into the passageway and is selectively movable along the passageway for shut-off and/or flow rate control of the spray flow by the related axial positioning of its seat end relative to the separate discharge orifice and valve seat element that is inserted at the outlet end of the passageway. The separate discharge element has an external configuration that conforms to a portion of the nozzle body adjacent the outlet end for such seating thereon. The element's internal configuration defines a small discharge orifice through the element and a valve seat around the inner end of that orifice in opposed relation to the seat on the valve needle. The configuration and seating relation of the discharge element on the nozzle body assure that the orifice and the valve seat of the element are coaxially aligned with the adjacent end of the valve needle. The needle and its drive bushing preferably are made in one piece. Atomizing fluid is supplied through a plurality of bores through the nozzle body around the discharge passageway. These bores may be of reduced cross-section adjacent the outlet, which affords greater strength in this area of the assembly.