| 摘要 |
1,235,052. Toothed gearing. NIPPON SEIKO K.K. 2 May, 1969 [2 May, 1968], No. 22556/69. Heading F2Q. In a vehicle steering gear comprising a recirculating ball type screw 5 and nut 3, the screw being rotatable with a steering shaft and the nut having on one side a rack 4 meshing a sector gear 2 on a rocker shaft 1, the sector gear is formed using a rack type gear cutter S having at least some of its blades S 1 -S 8 offset relative to the positions they would occupy in a uniformly toothed rack, the cutter being symmetrical about a central axis XX<SP>1</SP> and the rack 4 on the nut 3 having a tooth form and spacing substantially identical to that of the cutter S. This provides a steering gear in which the transmission ratio increases progressively as the sector gear is rotated away from its straight ahead position, to a predetermined angle, further rotation of the sector gear being at constant transmission ratio (Fig. 1, not shown). The blade offsets may be purely lateral, Fig. 8, or angular-i.e. a change of pressure angle-with or without lateral offset. The sector gear is conical to permit adjustment of backlash in known manner. |
