| 摘要 |
A single-unit and a multiple-unit earth worker are provided. An elongated frame has earth-working members supported therebelow. A transversely disposed support member is centrally and pivotally attached to the rear end of the frame to pivot in a horizontal plane. The forward end of the frame has a pivotally mounted hitch, and a pivotally mounted wheel. The rear support member has a caster wheel mounted on each end. A first link connects the rear support member and the forward wheel, the link restraining same in normal position and operable to horizontally angle the wheel. A second link connects the first link and is rigidly connected to the hitch. A restraining link connects the transverse support member at the rear and the frame to restrict the extent of pivotal movement of the frame about the transverse support member. Turning linkage connects the frame and the hitch member. In the multi-unit embodiment, a plurality of caster wheels is used, one on each end of the frame and on opposite sides thereof. Caster linkage is connected to the hitch and the end caster wheels, such being operable to position the caster wheels relative the frame. Angular linkage connects the hitch and the frame, with such operable to rotate the hitch to proper position in relation to the frame, and turning linkage connects the frame and the hitch.
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