摘要 |
There is disclosed a traction enhancing device for a wheeled agricultural tractor, in which a flexible frame comprises a circular band, to which are welded a series of spade holders. The frame is bolted to the rim of the wheel by spacers, so that the frame is in non-contacting relationship with the tire. The spade holders are fabricated from flat stock of high strength spring-like steel, formed into a semicircles, and have outer tubular anchors. These anchors encircle a plurality of wire ropes that lie in mutual end-to-end relationship and described a circle that is concentric with the wheel. A series of spade assemblies are rigidly fastened on the wire ropes. The wire ropes are preloaded, and can be rotated within the anchors so that the spades assemblies alternate between a ground-engaging position and a ground-avoiding position. The spades each include lugs that slice into the strong subsurface layers of the soil, and provide a significant degree of traction improvement as the wheel turns. The flexible frame and spades follow the tire's contour, thereby forming its own elongated footprint as the wheel turns. As there is no contact between the frame and tire, riding comfort is not adversely affected even at heavy pull on a dry soil surface. Under the influence of vertical load and drawbar pull the device deforms as the spades penetrate into the soil. The dimensions of the spade holders and their spring-like elasticity allows structural compression to repeatedly occur without permanent deformation.
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