Patent GB-797518-A (GB)
Title: Forging machines
IPC: B21J7/14
Filed: 1954-10-20
Abstract: 797,518. Forging. APPEL, G. H. Oct. 20, 1954, No. 30184/54. Classes 83 (2) and 83 (4). A high-speed forging-machine, Fig. 5, has at least one forging member or hammer 23 movable radially of a workpiece axis and actuated from an eccentric 67 through a driver 49, 50, Fig. 12, movable transversely of the member 23 and engaging rollers 51, 52 disposed between the driver, the forging member 23 and a rigid cam block 48, the roller engaging surfaces of the driver, the forging member and the cam block being curved concavely whereby the transverse reciprocation of the driver produces a radial acceleration of the forging member. The swaging-machine comprises a fixed block 29, Fig. 5, secured in a casing 11 and housing a plurality of radially-acting dies 22 actuated by the radially acting hammers 23, each operated by a transversely-reciprocable driver 49, driven by an eccentric 67 on a shaft 68. The dies are biased inwardly and the hammers are biased outwardly by springs 44, 37, respectively, Fig. 8 (not shown); the closed dies define a substantially closed orifice 31 for the central workpiece. The eccentrics carry connecting-rods 63, 64 secured by adjustable couplings 63a, 64a to the reciprocable drivers. Each driver consists of two outer parts 49, Fig. 7, secured to parallel connecting-rods 64 which are linked together by a bar 65 and connected to one eccentric shaft 68 and a central part 50 secured to the connecting-rod 63 which is connected to the opposite eccentric shaft. The cam members 49, 50 are caused to reciprocate in opposite directions. Both cam members have two curved cam surfaces engaging freely mounted rollers 51, 52, respectively, Fig. 12; the roller 52 engages a cam block 46 secured to the respective hammer 23 and the roller 51 engages a stationary cam block 48. The curved surfaces on the cam members 49, 50 and the cam blocks 46, 48 cause the hammers to accelerate during their strike so as to increase the impact of engagement with the dies. The rollers are formed in three separate hollow parts 53-55, Fig. 14 (not shown) corresponding to the cam members 49, 50 which they engage. Wear-plates are provided between the roller parts and they may be connected together by a coil-spring threaded therethrough which permits relative transverse movement of the roller parts. Each eccentric shaft has an eccentric 66, Fig. 7, for the connecting-rod 63 and a pair of eccentrics 67 for the dual connecting-rods 64. The eccentric shafts which are preferably in two parts with a toothed coupling 84, Fig. 17 (not shown) between them to facilitate their alignment, carry pinions which are in mesh with a common central gear 81, Fig. 4 (not shown), driven through spur gearing and a V-belt 70, Fig. 2, by an electric motor 69. The workpiece 17, which may be solid or hollow and of round or hexagonal cross-section, is gripped in a chuck 19 carried in a headstock 14. The chuck is rotated through a drive-shaft and the headstock is moved longitudinally by feed-screw 16 for feeding the workpiece through the swaging head. Variable-speed rotary hydraulic motors 27, 28 drive the lead-screw and the chuck respectively. A hollow workpiece 17, Fig. 9, may be swaged by the dies 22 over a mandrel 26 freely mounted for rotation and rocking movement on the end of a rod 25. The mandrel may have helical ribs 26d for forming grooves in the base of the workpiece which may be for a rifle barrel. The grooves 26d may taper in both width and depth at the exit end 26c to permit the swaged workpiece to free itself from the mandrel. The stationary cam blocks 48 are adjustable radially, so as to vary the opening defined by the dies 22, by wedges 89, Fig. 18, actuated by double-acting hydraulic pistons 92 working in cylinders 93. The wedges are also adjustable longitudinally by barrels 118 and locking screws 121. The cylinders 93 are supplied with pressure liquid through pipes 94 or 95 from central manifolds supplied through a control unit 100, Fig. 19, and a solenoidoperated distributing valve 106, by a constant delivery pump 97 provided with a relief valve 98. The control unit 100 contains a flow equalizer to compensate for changes in viscosity and temperature, a throttle valve, and an overload relief valve. The pistons are linked by levers 114 to a master cylinder 111, movable over a fixed piston 113, supplied with pressure liquid from the manifolds. The master cylinder ensures that the movements of the wedges are in synchronism. For producing tapered workpieces the movement of the wedges is controlled automatically by the feed movement of the headstock 14 by controlling the solenoid valve 106, Fig. 19, and the throttle valve in the control unit 100 by dogs 123 and a cam surface 122, respectively, Figs. 15, 16 (not shown), which are engaged by the moving headstock. The taper may be in either direction. During the setting of the machine, strain gauges may be used on the connecting-rods 63, 64 whereby the couplings 63a, 64a, Fig. 5, may be adjusted until these gauges read equally, thus ensuring that the transverse forces transmitted to the hammers are balanced. Making rifle barrels and splined couplings.- The machine may be used for forming rifle barrels and splined couplings, Fig. 29 (not shown), with high surface finish without machining operations. Altering physical structure.-The physical structure of the metal is altered by the swaging resulting in a hard dense structure with increased tensile strength, surface hardness and resistance to corrosion. These results are stated to be obtained with steel, brass, bronze, aluminium, titanium and berryllium copper workpieces. Specification 768,834 is referred to.