| 摘要 |
370,992. Lawn-mowers. JERRAM, A. E., Inglenook, The Oval, Oadby, near Leicester. Jan. 3, 1931, No. 7385/32. Divided on 370,485. [Class 6 (ii).] Rotary cutters for lawn-mowers comprise a shaft A having steel discs B welded or brazed thereto and one or more series of spiral blades C somewhat longer than the distance between adjacent discs, each blade being electrically butt-welded at each end to the discs on that surface remote from its cutting edge. The blades C are made from wedge-shape section steel-strip being narrow at the edge and thickened at the base. Each blade in turn is held at each end for welding by clamping devices on the welder opposite the discs, the shaft being supported in insulated bearings. The electric circuit is completed by copper blocks contacting with the shaft, projecting forward from the side of the cutter opposite to the blade clamp. The blades are uneven in number to facilitate the insertion of the blocks. The heating may be prevented from spreading to the cutting edge by an air blast or water circulation.
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