Abstract: An improved valve rotator includes a plurality of biasing springs which are effective to urge associated balls toward the shallow ends of ramps formed between a pair of housing members. The total force applied against the balls by the biasing springs is sufficient to hold the housing members apart against the influence of a valve spring when the valve is in a closed position. Upon movement of the valve toward an open position, the valve spring force increases to a magnitude sufficient to cause the balls to move down the associated ramps against the influence of the biasing springs. As the balls move down the ramps, rotational movement of the balls causes one of the housing members to rotate relative to the other with a resulting rotation of the valve as it opens. As the valve subsequently moves toward the closed position, the valve spring force decreases and the ball biasing springs are effective to move the balls up the ramps to separate the two housing members against the influence of the valve spring.

Abstract: A valve rotator includes first and second parts which are mounted for movement relative to one another axially and rotatably along and about a longitudinal axis. Rotation imparting means is positioned between the parts for imparting a predetermined angular degree of relative rotation therebetween upon movement of the parts toward one another, and for imparting a different angular degree of relative rotation therebetween in an opposite rotational direction upon movement of the parts away from one another.

Abstract: A rotator for a valve which is reciprocable along a longitudinal axis between open and closed positions and which is rotatable about such axis. The rotator includes a pair of parts movable axially and rotatably relative to one another along and about the longitudinal axis. Variable force applying means in the form of a spring urges the valve toward its closed position and also urges the pair of parts toward one another with forces which alternately increase and decrease in magnitude during opening and closing movement of the valve. The valve is rotated during axial movement thereof by relative rotation between the two parts which is produced by a plurality of shiftable elements located between the parts and movable along separate paths which are dimensioned and positioned so that all of such paths taken together have a total path length which is greater than the circumference of a reference circle drawn about the longitudinal axis and passing through the midpoints of the paths.