| 摘要 |
955,699. Toothed gears. ILLINOIS TOOL WORKS Inc. July 6, 1960 [July 7, 1959], No. 23661/60. Heading F2Q. [Also in Division B3] A concave hob has teeth 32 with unequal pressure angles 42, 44 and which are formrelieved by moving the relieving tool 52 at an angle 56, which is a fraction of the difference in the pressure angles, to a plane perpendicular to the hob axis. The hob cuts an annular gear 22 to mesh with a straight tapered worm 24 which may have one or more threads of uniform lead and unequal pressure angles as described in Specification 774,128. The hob is cut from a tapered blank 28 by a tool 34 traversed along a path 36. The relieving tool 52 is moved towards the hob axis 38 along a line 54 as the hob is rotated so that the side clearance angles 46, 48, Fig. 4, are equal or nearly so. |
