GB434811A - An improved rotary harrow or cultivator - Google Patents

Abstract

434,811. Implements and machines for working land. NICHOLSON;, A. C., Trent Iron Works, Newark-on-Trent. March 3, 1934, No. 6853. [Class 6 (i)] A wheeled rotary harrow or cultivator comprises one or more pairs of rotatable shafts carrying radial tines, blades, or the like, the shafts of each pair being inclined to the line of draught in opposite directions and being coupled together so as to rotate in unison. The spikes may be arranged in four lines along each shaft. They may be so spaced along the lines as to produce oblique cuts distinct from or merging into one another. Shafts may be arranged at an angle of 45‹ to the line of draught and the spikes may be fastened to sleeves 25, Fig. 4, thereon coupled together by bevel gearing 30, a flexible shaft, universal joints, or other means. The shafts may be mounted in downwardly projecting parts of a triangular frame supported by three wheels. The front wheel 34 is a swivelling wheel and is adjustable vertically by means of a screw operated by a crank handle 36. The rear wheels 44 are mounted on arms on a shaft 40 and are adjustable by rocking the shaft 40 by means of a screw 47 screwing into a nut 48 on a pivoted bridle 49. The front sets of spikes 8 on the two sleeves 25 may mesh with one another, and the bevel gearing 30 may be dispensed with. In an implement in which two pairs of inclined spiked shafts are employed, one of the shafts of the rear pair is arranged behind the gearing connecting the front pair together, and the gearing connecting the rear shafts together is arranged behind one of the shafts of the front pair, so that no ground is left unworked. This implement has two wheels on an adjustable front draw-bar, and an adjustable wheel at the rear. In another arrangement comprising two pairs of spiked shafts, the spikes and shafts are so arranged that the two sets of bevel gearing are behind one another and a mutual scraping action is effected by the spikes of the two pairs of shafts. In the arrangement shown in Fig. 10, curved clearing bars 96 are provided between the sets of spikes. Instead of the spikes 8, longitudinal flanged plates 94, Fig. 12, may be bolted to the faces of a polygonal sleeve 92 mounted to rotate on a shaft 6, the plates being thin in the direction of rotation like the spikes 8. A spiral arrangement of the spikes on the shafts may be employed. The spikes may be shouldered and screwthreaded so as to screw into a polygonal sleeve. They may be flat and provided with a cutting edge directed longitudinally of the axis of rotation. A series of spikes may be produced from a pressing or disc 82, Fig. 21, the disc being deeply notched to produce arms or spikes 85. The arms may be twisted as at 87 and provided with points 88 and bevelled edges 89. A double-ended spike 90, Fig. 19, may be passed through a shaft 6 and secured by a set-screw 91. According to the Provisional Specification sub-frames carrying the spiked shafts may be connected together flexibly.