Patent GB-914329-A (GB)
IPC: B21H5/02
Abstract: 914,329. Rolling. GROB, E. Jan. 13, 1959 [Jan. 13, 1958; July 19, 1958], No. 1263/59. Class 83 (4). In a method for longitudinal profiling of workpieces, having a cross-section symmetrical about a longitudinal axis, e.g. splined shafts, splines or gear-wheels, by cold-rolling, there is relative movement in a direction longitudinal to the work between the work and several profiling rollers acting simultaneously on profiles spaced apart with at least one other profile between which is not at that time engaged by a roller but which is worked in the same manner immediately afterwards. The machine frame 1, Fig. 1, carries a tool-holder 8 fixed to spindles 5, 5<SP>1</SP>, 5<SP>11</SP>, the whole assembly being reciprocable by a crosshead 7 and a crank 4. The work w is located by a backstop 20 and held in an hydraulically-operated clamping attachment 9 of a work-holder 2, the clamping attachment 9 being intermittently rotatable through gearing, and a Maltese Cross transmission by the main motor drive 13 in synchronism with the reciprocations of the tool-holders 8. Profiling rollers 21 mounted in carriers 15 attached to the tool-holder 8 form longitudinal profiles on the work w, the rolls being circumferentially spaced apart so that alternate profiles are formed by any on pass. The rollers 21 constantly engage the work on the working stroke and are lifted clear of the work on the return stroke, the work being indexed by half the pitch of the rollers after each pass. Repeated passes may be made and the roller carriers 15 are fed in radially after each pass by a cam-ring 16 (Fig. 2, not shown), driven from the main-drive 13. Since the workpiece is not totally enclosed by the rollers on a particular circumferential zone plastic flow of the metal is limited to the periphery of the work resulting in increased accuracy. Alternatively. two or more groups of rollers may be attached to the same toolholder, the rollers 21<SP>11</SP> of one group being spaced axially of the workpiece from the rollers 21<SP>1</SP> of the first group, Figs. 4 and 5. By imparting a rotary movement to the workholder during rolling helical toothings may be formed. In a modification planetary rollers 31, Fig. 7, mounted in percussion heads 27 each rotatable on a shaft 28 form the profiles step by step, the work being oscillated through an angle equal to the pitch of the profiles. Alternatively, the work may be intermittently and progressively rotated in synchronism with the roller action. The percussion heads are each driven by a motor through a belt drive and gearing (Figs. 9, 10 and 11, not shown). The action of the rollers on the work is synchronized either by an annular toothed wheel 45 (Fig. 10, not shown), which meshes with a spur gear on each motor shaft or by the interconnection of the planetary shafts by bevel gearing (Fig. 11, not shown). The bevel gearing is axially adjustable within small limits to permit progressive increase in the depth of profile. The percussion heads are mounted in a frame 36<SP>1</SP>, Figs. 12 and 15, carried on a bed 50 and the work is clamped and fed forward by a support 64, the front end passing through support brackets 28. The percussion heads are synchronized by bevel gearing adjustably attached to the planetary spindles, one of the latter being connected to a cardan shaft 63, Fig. 14, in turn connected to a rotary drive for the workpiece so that the latter rotates in synchronizm with the roller movements. The percussion heads are adjusted radially of the work by screws 59 to accommodate different diameters of work, the bevel gearing 47, 48 being adjustable axially of the planetary spindle 52. In another modification, rollers 26, 26<SP>1</SP> mounted in percussion heads 27, Fig. 6, are arranged in two groups, the rollers 26<SP>1</SP> being spaced axially of the work from the rollers 26. The rollers 26 act simultaneously on the work at a different time from the rollers 26<SP>1</SP> which also act simultaneously. Percussion type rollers mounted in swivel bearings may be used for forming oblique profiles.