Characteristics of harrow teeth.
The teeth of the harrows are rigidly connected to the truss of the supporting frame and act as wedges with a vertical working edge. Teeth can have different sections. Moreover, they can be straight or curved. The circular tines are used for harrowing to cover the seeds. Square teeth are used to break up and crush lumps. They must be positioned with their edges in the direction of the harrow's movement. Curved knife teeth are used to pluck and extract couch grass roots and other weeds. The tines of the harrows are arranged in such a way on the field truss, that they show traces at equal intervals. Then the role is evenly protected. Attaching the tines to the truss should protect them against self-loosening. For this purpose, sheet metal washers folded on the frame and the tooth fixing nut are used. The operation of the harrow is correct, if all her teeth work at the same depth, because then each lump may collide with the teeth of the harrow many times. Such conditions are then maintained, when the harrow attachment line passes through the center of the harrow field. If the harrow linkage chain is too short, the front of the harrow is raised during operation. If the hitch chain is too long, then the front of the harrow goes too deep, and the back - too shallow. The harrow then "jumps."” and tends to overturn.