Flow control device for a fluid dispensing apparatus

Claim 2

(2) The flow control device of Claim 1 wherein said first pitch and said second pitch are of the same hand.

Claim 3

(3) An improved flow control device for a liquid-dispensing apparatus having a body with an axial bore therein, a nozzle communicating with one end of the bore and having a nozzle orifice and a valve seat in the nozzle orifice, a needle valve engageable with the valve seat to control the flow of liquid through the nozzle orifice, and means to move the needle valve within the axial body bore into and out of sealing engagement with the valve seat, comprising: a sleeve-stop member axially movable in the body bore, said sleeve-stop memeber having opposed ends,, one end of said sleeve-stop member forming an end stop to the movement of the needle valve away from the nozzle orifice, external screw threads of a first pitch formed on a portion of said sleeve member, means for preventing rotary movement of said sleeve-stop member in the body bore, internal screw threads of a second pitch different from said first pitch formed on the body within the axial bore thereof, and adjustment screw means for adjusting the maximum length of travel of the needle valve away from the nozzle orifice, said adjustment screw means including a cylindrical portion externally threaded with threads of said second pitch engaged with said second pitch threads of the body, and internally threaded with threads of said first pitch and engaged with said first pitch threads of said sleeve-stop member, rotation of said adjustment screw means causing differential axial movement of said sleeve-stop member for adjustment of the maximum needle valve travel.

Claim 4

(4) The flow control device of Claim 3 wherein said first pitch has more threads per inch than said second pitch.

Claim 5

(5) An improved flow control device for a liquid-dispensing apparatus having a body with an axial bore therein, a nozzle communicating with one end of the bore and having a nozzle orifice and a valve seat in the nozzle orifice, a needle valve with an elongated stem, one end of the needle valve engageable with the valve seat to control the flow of liquid through the nozzle orifice, the other end of the needle valve having a piston thereon, the needle valve being axially movable within the axial body bore into and out of sealing engagement with the valve seat by fluid pressure applied to the valve piston, comprising: an elongated sleeve member received in the body bore for axial movement therein, one end of said sleeve member forming a stop to the opening movement of the needle valve, the other end of said sleeve member having external screw threads of a first pitch formed thereon, means for preventing rotary movement of said sleeve member in the body bore, internal screw threads of a second pitch formed on the interior of an upper portion of the axial body bore, said screw threads of said second pitch having more threads per inch than said first pitch, said threads of said first and second pitches being of the same hand, and an adjustment screw element with a tubular portion having external threads of said second pitch engaged with the internal threads of said upper body bore portion, and internal threads of said first pitch engaged with said external sleeve member threads, such that axial rotation of said screw element causes said sleeve member to move a distance proportional to the pitch difference between said second and first pitches for fine adjustment of the maximum travel of the needle valve away from the valve seat.