GB592771A - Method of and apparatus for producing a knurled surface - Google Patents

Abstract

592,771. Knurling annular bodies. GENERAL MOTORS CORPORATION. May 30, 1945, No. 13518. Convention date, June 6, 1944. [Classes 83 (ii) and 83 (iv)] Making bearings.-A method of knurling a cylindrical surface comprises rotating the part to be knurled and a knurling-tool relative to each other, forcing the knurling-tool into the part to be knurled until the tool bites into the surface, said knurling-tool including a number of knurls having an angular lead relative to the axis of the part to be knurled and then permitting the tool to feed itself throughout the remainder of the part. A tool for knurling internal surfaces comprises an arbor 22 supporting three knurling rolls 26 arranged at angles of 120‹. Each roll includes stub shaft portions 28 at each end journalled in bearing-sleeves 31 in the arbor and in a cap 32 secured to the arbor by screws 38. The shafts 28 have end clearance within the bearing-sleeves to permit the roll to move axially to make up for slight discrepancies between the pitch of the knurls and the pitch of the screw feed between tool and work. To assist in feeding the knurling-tool through the annular work, a slight angular lead is provided on each roll. In Fig. 2 this is shown as 19 minutes. This angle may vary for knurls of different pitch and may be a multiple of the number of rolls used, being for example 57 minutes instead of 19 minutes when three rolls are employed. For knurling the outer surface of a cylindrical body, the knurling-rolls are carried in an annular arbor. In either case either the tool or the work may be traversed. The knurling produced by the method is stated to be of greater accuracy and particularly useful for the knurling of the supporting surface of a bearing, a copper surface being knurled and then filled with bearing metal.