| 摘要 |
A self-sharpening tool blade is to be used on shovels, spades, cultivating tools, garden hand tools, and other tools and mechanical equipment which need to have consistently sharp cutting edges in order to penetrate into and dig in the ground. The blade utilizes the concept of differential surface wear for self-sharpening. The back side of the tool blade sustains more wear than the top side, since it is most often in contact with more abrasive soil and earth debris, while the blade's top side is usually in contact with abrasive materials which exert less abrasion and less pressure than that which the back side experiences. This is due to the manner in which digging occurs; that is the top side of the blade contacts soil and soil debris which is free to move away from the blade during digging, whereas soil material contacting the back side of the blade is, for the most part, compacted and immovable, providing a higher degree of abrasive friction. The difference in abrasive forces and pressure differential between the top side and back side of the blades serves to maintain and, over time, sharpens the taper angle of the blade.
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