| 摘要 |
1491808 Castors G E W LEWIN 20 Feb 1975 [21 Feb 1974] 7212/75 Heading A4U A castor comprises a sheet metal mounting plate I and a sheet metal fork (6) pivoted thereto, the plate 1 having an annular flange (5) surrounding a central aperture and providing a portion of an inner ball race for balls 4, and the upper end of the fork being hollow and provided with an outer ball race 11 of unitary construction. In Fig. 1, the inner ball race comprises a portion 3 of the flange and a portion 8 of an apertured disc 9 cut out of the upper end of the fork, a part 12 of the flange being folded to secure disc 9. In a modification (Fig. 4, not shown), the disc 9 is welded to the flange. In Fig. 10, the inner race comprises a portion 17 of the flange, and the outer race 11 is formed on an annular portion 19 welded to the remainder of the fork. |
