Tine support and drive mechanism for a compact self-propelled lawn aeration machine having means for varying both forward travel speed and depth of tine penetration

摘要

Paired, side-by-side sets of upper and lower sprocket wheels are commonly chain driven at similar speeds. Crank arms are pivotably mounted at their upper ends to the upper wheels of each set and project slidably through cylindrical bushings fixed to journals rotatably mounted to the lower wheel for rotation about the journal axes, radially displaced from the axis of rotation of the lower wheels. Tines are mounted to the lower ends of the crank arms for penetration into and extraction from the turf to aerate the turf. Machine propulsion is effected automatically as a result of driving the tines into the turf and retraction of the same. Holes at different radial positions within the upper and lower wheels permit the crank arms to be mounted to the upper wheels at different radial positions to control the depth of tine penetration into the turf. Holes at different radial positions within the lower wheels permit mounting of the journals and thus the bushings through which the crank arms slide at different radial positions relative to the axis of rotation of the lower wheels to vary the travel of the tines during penetration and removal from the turf to vary the forward travel speed of the machine. Alternatively, some or all of the wheels for single or multiple wheel sets may constitute idlers which are chain driven and mount either crank arms or jack shafts fixedly bearing a tine at their lower ends.