Spray gun with improved needle shut-off valve sealing arrangement

摘要

A gun-like spray device (10) has a spray nozzle assembly (12) at the discharge end and a reciprocatably movable valve needle (15) for controlling the liquid flow through the discharge nozzle assembly. The nozzle assembly (12) includes an orifice member (46) which defines a liquid discharge orifice (61) and a rigid valve seat (70) for centering and precisely locating the valve needle (15) in a closed position. An annular resilient sealing member (78) is secured within the orifice member (46) for engaging and creating a liquid seal about the valve needle (15) separate and apart from the rigid seat (70) when the valve needle (15) is in a closed position. The spray nozzle assembly may be used with spray devices having different sized valve needles and includes a first rigid valve seat (70) downstream of the resilient sealing member (78) for receiving a relatively small diameter valve needle and a second rigid valve seat upstream (88) of the resilient sealing member (78) for receiving a relatively large diameter valve needle.