| 摘要 |
945,932. Making bearings. RIV OFFICINE DI VILLAR PEROSA S.p.A. Nov. 19, 1962 [Nov. 25, 1961; May 11, 1962], No. 43695/62. Heading B3A. [Also in Division F2] A method of manufacturing a cage for a needle bearing of the type comprising a pair of crown sections 21, 22 connected by bars 25 defining roll-windows 24 therebetween and wherein opposite end chordal surfaces 27 form roll guides, comprises the steps of forming a blank 20 with the roll windows extending into each crown section by a pre-end portion 24a of less width than the roller diameter, followed by an end section 24b of width greater than the roll diameter and slotting the flanks of each of said pre-end portions of each window over a radially limited extent to form said chordal surfaces. Both flanks of each pre-end portion are slotted simultaneously by a tool 26 which reciprocates in a plane containing the axis of the cage. The direction of reciprocation is inclined to said axis by an angle " Y "smaller than 90 degrees so that a small triangular portion 28 is left on each flank. If the radial dimension of this triangle is too great the slotting operation is repeated in an oppositely inclined direction to leave a portion 29 having the shape of an inverted isosceles triangle. In a modification the material is removed by a flat-cup shaped grinding wheel, which is thin enough to be partly inserted into a window in the cage blank and then moved in the direction of the axis of the wheel. In a further modification, Fig. 8, the slotting is performed by a tool 226 which reciprocates parallel to the axis of the cage and removes material from each of the pre-end portions to leave lands 229 and 230. The slotting tool is shaped to leave the surfaces 227 either planar or curved. |
