FLOW CONTROL DEVICE FOR A LIQUID DISPENSING APPARATUS

摘要

An improved liquid dispensing apparatus having a micro-adjustment of the opening travel of a needle valve of the apparatus. This micro-adjustment comprises a sleeve-stop member which is axially movable but non-rotatable in the body of the apparatus. One end of the sleeve-stop member forms an end-stop to limit opening movement of the needle valve away from the valve seat. Screw threads of a first pitch are formed on an external portion of the sleeve-stop member and internal screw threads of a second pitch different from the first pitch are formed on a portion of the apparatus body. A generally tubular adjustment screw element is engaged with both the internal scew threads of the body bore and the external screw threads of the sleeve-stop member so that rotation of the adjustment screw element causes differential axial movement of the sleeve-stop member for fine adjustment of the maximum opening needle valve travel.