| 摘要 |
<p>On shaft (1) are flanges (2) to which are attached the blades (3). The leading edge (4) of each blade has a curved profile which tangentially meets that of flange (2) and the rolling circle of contact (5) the ground. The tip of the blade projects from the flange (2) in such a way that it is the last to enter the soil. As a result of this arrangement, the blade enters the soil progressively, avoiding any jarring. The trailing edge (6) of each blade (6) is straight and each blade increases in breadth from the tip (7) to the point of attachment (8). The blade tips are bent at an angle of 45 deg. to improve soil breaking and to avoid the formation of a pan.</p> |
