| 摘要 |
622,839. Rolling wheels. STIVIN, J. Oct. 4, 1946, No. 29682. Convention date, Sept. 4, 1942. [Class 83 (iv)] In a method of making metal gears, the surface layers of the blank are rapidly heated by induced high-frequency currents without heating or softening the inner core and the blank is then subjected to a rolling operation in contact with a toothed tool. In one form, Fig. 1, the work 13 having reduced ends 13<SP>1</SP> is held between chucks 11 and 12 supported in bearings 7 and 8 on a slide 2 movable along a frame 1 by means of a nut 6 co-operating with a screw 5. In operation, the slide 2 is first moved to its lowermost position, a high-frequency current is then passed through a fixed coil 23 surrounding the work and the slide is slowly raised so that the work moves progressively through the coil. At the same time the work is rotated by gears 22, 21, 18 and 20 and a toothed roller tool 14 is rotated in contact with the work to form teeth in the softened surface layers of the work. In a modification, Fig. 3, a blank 110 is heated in a high-frequency coil 118 and is then moved by a lever 116 to a position between two platens in the form of toothed racks 111 which are moved together to grip the blank by means of pressure devices 115 and are reciprocated to form teeth on the blank by means of a gear 108 meshing with the racks and driven through gears 107 and 102 from a crank disc 105 from which the blank is similarly rotated through a gear 106. After being formed, the blank may be moved by the lever 116 into a hardening device 119. Drawing.-The Specification as open to inspection under Sect. 91 comprises also a modification in which the blank is moved longitudinally by a screw, first through a heating coil and then through a circular die, the working of the blank being effected within a casing through which an inert gas is passed. This subject-matter does not appear in the Specification as accepted. |
