| 摘要 |
A head (18) for a powered earth-working tool (12) is adapted to be driven by a rotating shaft (28) which is driven by the prime mover (14) of the tool. The head includes a housing (36) having an opening for the shaft; a driver gear (48) in the housing fixed to the shaft which rotates with the shaft about an axis (70): an axle (52) in the housing disposed perpendicularly to such axis of rotation and carrying a driven gear (64) on a portion of the axle away from the ends to mesh with the driver gear and rotate the axle; a pair of pins (e.g., 76), offset from the axis of the axle, mounted to move with the rotation of the axle, 180 DEG out of phase with each other; a pair of spindles (88, 102) the housing disposed substantially parallel to the axle; a pair of connecting rods (86, 110) each having an opening (e.g., 84) to receive one of the pins and being mounted to swing from one of the spindles about the axis of the spindle; and a pair of earth-working members (32 and 34; 120; or 128) each fixed to one of the connecting rods to swing from the associated spindle about the axis of the spindle in a pendulum-like oscillation 180 DEG out of phase with the other member. The head has wheels (112) for rolling support; also, a roller (120) is adapted to fit over such wheels to provide an alternative form of rolling support. The members can take particular alternative forms for hoeing (32 and 34), digging trenches (128) or cutting and lifting sod (120). The trench-digging form has a first elongated portion (130) extending from the vicinity of the housing, a second |
