1944 



MACHINERY 



MACHINERY 



The general-purpose plow strikes an average between 

 these two as regards shape and operation, and may be 

 used either in stubble or light sod. 



Deep plowing is objectionable in some soils, particu- 

 larly in those having a sand or gravel subsoil, owing to 

 the fact that it is inadvisable to bring this subsoil 



plowing in sod, it may be set closer to the landside and 

 should run the entire depth of the furrow. 



The jointer (Fig. 2252) should be used when there is 

 trash or organic matter on the surface which is not 

 thoroughly covered. This implement is attached to the 

 plow-beam in front of the plow and can be gaged to any 

 required depth. As the trash is turned, it strikes the 

 previous furrow a little below the top and is completely 



2252. Deep-tilling plow equipped with jointer and coulter. 



should be about 



material too near the surface. Such soils may, however, 

 be plowed deeply if the proper plow is used. Fig. 2252 

 illustrates a deep-tilling plow, which, it is asserted, is 

 adapted for the deep pulverization of a soil, the sub- 

 surface soil of which should not be brought to the sur- 

 face. It has a broad share and the moldboard is very 

 narrow at the point where it joins the share but widens 

 gradually at the upper end. The share loosens and pul- 

 verizes the bottom part of the furrow-slice which then 

 falls through the space between the outer edge of the 

 moldboard and the wing of the share, thus preventing 

 its being brought to the surface. The broad part of the 

 moldboard turns the upper 

 part of the furrow-slice in the 

 usual way. 



The material of the plow- 

 beam may be either of wood or 

 iron. While the iron beam is 

 perhaps lighter and more wieldy 

 than the wooden beam, it is 

 likely to bend out of shape 

 when the plow strikes a root or 

 stump. The wooden beam will 



probably break under the same 2253 K^ coulter fastene d to plow beam, 



circumstances and can be re- 

 placed. The steel beam is curved over the moldboard 

 and down to the landside. The wooden beam is fast- 

 ened to the plow by a beam standard. The plow- 

 handles are usually of wood and are fastened to the 

 beam. 



A beam-wheel (Fig. 2248) is usually fastened to the 

 plow beam, the function of which is to aid in regulating 

 and maintaining the depth of plowing. Its proper 

 adjustment is secured when it simply rolls on even 

 ground without carrying weight. 



The more common types of coulter (Figs. 2253, 2254) 

 are the knife and rolling types. The coulter is used 

 chiefly in sod-plowing but may be used in any soil. 

 When the coulter is thick, dull, and improperly located 

 on the beam it is likely to increase the draft. If, how- 

 ever, it is so located just behind the plow point as to 

 cut directly above where the point and share are cut- 

 ting and lifting the soil, the two parts of the plow should 

 assist each other materially. When the 

 ground is covered with wet corn-stalks, 

 the rolling coulter should usually be set 

 high and slightly back of the point. In 

 very trashy ground it is often advantage- 

 ous to set the rolling coulter well for- 

 ward, but not on very hard ground. For 

 stubble ground the rolling coulter had 

 best be set about % inch outside of the 

 landside and run one-third to one-half 

 the depth of the furrow. For shallow 



2255. Subsoil plow. 



covered by the furrow-slice as it turns from the mold- 

 board. In this way trash, and the like, is completely 

 covered but not too deeply. Sod especially can be 

 deep plowed when the jointer is used. 



It is often necessary to use a subsoil plow when the 

 soil conditions are such that deep plowing is out of 

 the question. The modern subsoil plow (Fig. 2255) is 

 built more or less on the principle of a coulter. It cuts 

 a narrow gash in the soil, the depth of which is regulated 

 by a beam-wheel, and the small point forms a sort of 

 reservoir for water. The subsoil is thus aerated and 

 the capillarity is generally improved. 



In regard to the operation of walking-plows, it may 

 be stated that a walking-plow is very sensitive to soil 

 conditions, depth of plowing, the nature of the hitch, 

 the set of the coulter or of the 

 beam-wheel, and the set of the 

 share. A walking-plow should 

 usually be balanced about the 

 point and run level. The prop- 

 er set of the share point to 

 secure penetration is shown in 

 Fig. 2256a. There should be 

 Yg to % inch of suction at 

 point A. Hard plowing requires 

 slightly more suction. Fig. 

 22566 shows the clearance in 

 the throat of the share, which 

 inch at point B. 



Walking-plowshares have what is called a wing bear- 

 ing. That is, a straight edge as shown in Fig. 2256c 

 when placed at the rear of the landside point c and 

 extending to the wing of the share point D should touch 

 the share bottom from % inch to 1 % inches back of the 

 edge, according to the size of the plow. The point of 

 the share is also turned outward to the land to cause 

 the plow to follow directly behind the team. As shown 

 in Fig. 2256d, the clearance at E should be about ^ inch. 

 The plow must scour in order to operate satisfactorily; 

 that is, the share and moldboard must be of hard 

 material taking a smooth polish so that the furrow-slice 



2256. Plow adjustments. 



