Plunger pump for delivering liquids especially fuels, for reciprocating internal combustion engines

Claim 1

A plunger pump for delivering liquids, particularly for delivering fuels to reciprocating internal combustion engines, comprising a casing having an outlet; a barrel in said casing; a plunger reciprocably and angularly displaceably installed in said barrel and arranged to expel liquid via said outlet while performing a delivery stroke in said barrel and to move relative to said barrel without expulsion of liquid while performing a lift stroke preceding the respective delivery stroke; a tappet reciprocably installed in said casing and indirectly coupled to said plunger to impart reciprocatory movements thereto; means for reciprocating said tappet including rotary cam means for moving the tappet axially in a direction to cause said plunger to perform forward strokes each of which includes a lift stroke followed by a delivery stroke, and spring means yieldably opposing the movement of said tappet under the action of said cam means, said casing and said barrel having means defining a path for the flow of liquid into said barrel while said plunger performs a return stroke under the action of said spring means and for the flow of liquid from said barrel into said outlet when the plunger performs a delivery stroke, said plunger having a control edge arranged to alter the volume of liquid, which is expelled via said outlet during a delivery stroke of said plunger, in response to angular displacement of said plunger in said barrel; first drive means for changing the angular position of said plunger in said barrel including a first sleeve having at least one first jaw and axially movably guiding said plunger, at least one second jaw provided on said plunger and arranged to receive torque from said first jaw, and means for rotating said sleeve; and second drive means for changing the axial position of said plunger relative to said tappet to thereby vary the lift and return strokes of the plunger, including a second sleeve having at least one third jaw, a one-piece pressure member coupled with said plunger for axial movement therewith and having first threads mating with second threads provided on said tappet and at least one fourth jaw arranged to receive torque from said third jaw, and means for rotating said second sleeve to thereby move said pressure member and said plunger axially of said tappet by way of said third jaw and said threads.