| 摘要 |
1,165,297. Mowers. SPERRY RAND CORP. 22 May, 1968 [25 May, 1967], No. 24303/68. Heading A1F. A rotary cutter unit comprises a knife carrier disc 12 mounted for rotation about a vertical axis, a knife 20 pivotally mounted on the carrier disc 12 by means of a fixed pivot 40 so as to project beyond the periphery of the disc 12 and a leaf spring 50 bolted to a web plate 15 attached to the carrier disc 12 and bearing against the knife 20 to retain it in position but adapted to be forced away to allow easy removal of the knife. The knife 20 consists of a rectangular flat plate with parallel edges each of which has a pair of bevelled cutting edges 28, 29 and 30, 31. The knife is secured to the carrier disc 12 by passing the T-shaped head 46 of the stud 40 through slot 34 in the knife 20 and turning it through ninety degrees. The key 42 of the stud is fitted into slot 48 and the carrier bears against flange 44 and the stud secured in position by nut 56. The knife is then free to retract or pivot when it hits an obstruction and may be removed by forcing back the spring 50 and turning the knife through 90 degrees. Other forms of blade or knife carriers such as bar or a triangular shaped plate may be used and the knives may be mounted on the upper surface. |
