| 摘要 |
932,583. Making discs for rotary cultivators. INTERNATIONAL HARVESTER CO. May 21, 1962 [July 17, 1961; May 14, 1962], No. 19446/62. Classes 83 (2) and 83 (4). A method of forming notches in a cultivator disc comprises subjecting a disc blank to a single stroke of a press so as to firstly cut a series of notches in its periphery, and secondly to forge the peripheries of the notches to form an inclined surface from the sheared edges of the notch, said inclined surface intersecting a face of the disc. A disc blank has its periphery turned to an acute angle 13 (Fig. 1), is heated to approximately 800‹ C. and placed on a die 15 for simultaneous forming of the notches. Referring to Fig. 5, the blank is held between a pressure plate 17 and the die 15 ; as seen, each punch 18 has a parallel portion which shears the blank to form the notch, and a chamfered portion 21 which forges the edges of the notch at an angle to form a cutting edge. The notches may be formed singly, or in groups if the press capacity so requires. The cultivator disc is finally dished and heat treated. Specification 722,748 is referred to. |
