Abstract: The object of the present invention is to provide an aerator for turf which is capable of adjusting the level of the pressing rollers relative to not only the irregularity in its travelling direction but also that in the lateral direction, thus enabling a structure in which a pair of the pressing rollers are rocked, which structure causes an increase in the total weight of the aerator, to be removed. The aerator for turf according to the present invention for injecting high pressure liquid through a plurality of nozzles disposed in its lateral direction in the ground and smoothing ground by a pressing roller after injection, includes a supporting structure for spotting the pressing roller at a frame such that the pressing roller tilts freely relative to the horizontal line in a lateral direction and moves freely vertically relative to the frame, and a biasing structure for biasing the pressing roller downward.

Abstract: A plunger pump suitable for an apparatus for injecting liquid under high pressure through a plurality of nozzles (104) into the turf. A plunger (34) of the pump is connected through a connecting rod (39) to a crank shaft (12) for the reciprocation thereof, and the crank shaft is more quickly rotated through its angle of rotation at the discharge stroke than through the angle of rotation at the suction stroke of the plunger to increase discharge pressure of the liquid upon its intermittent injection.