Patent GB-696458-A (GB)
Title: Feed device for pilgrim rolling mills
IPC: B21B21/06
Filed: 1951-09-05
Abstract: 696,458. Rolling tubes. CALMES, A. Sept. 5, 1951 [Sept. 9, 1950], No. 20951/51. Class 83 (iv). A feeding device for pilgrim rolling mills for producing seamless tubes comprises a mandrelcarrying piston movable in a cylinder and fluid pressure means for rotating the piston about its longitudinal axis at each end of its stroke, said means being synchronized with the rolls of the mill. In an embodiment a doubleacting hollow piston 20 carries a mandrel M by means of a holder 23 and operates in a cylinder 22, the bead of which is formed by an adjustable piston 25 for varying the residual volume of the cylinder 22. Valves a, a<SP>1</SP> and b, b<SP>1</SP> supply and exhaust respectively compressed air to and from the cylinder 22 and these valves are operated by a cam-shaft 27 synchronized with the rolls of the mill. The piston and mandrel are rotated independently of the stroke of the piston by means of a toothed segment 30, Fig. 5, on a ring 29 splined to the piston, the segment meshing with a rack 31, which forms the rod of one of two pistons 32 and 32<SP>1</SP> movable in opposed cylinders 33. The rack or rod 31 of the piston 32 has a screwthreaded bore for receiving a screw-threaded rod 34 of the piston 32<SP>1</SP>. The stroke of the piston is adjusted by rotating the rod 34 by means of a prismatic rod 35 and a wrench. The maximum stroke rotates the piston and mandrel through 135 degrees and the minimum through 45 degrees. Rotation of the piston and mandrel is effected when the rolls are not engaging the ingot by introducing air pressure through spring-loaded valves 37 controlled by a cam-shaft 38 driven from the camshaft 27 by a helicoidal coupling 39 and a shaft 40. The hydraulic brake for the piston 20 consists of a double-walled member 41 having an inner cylindrical wall and an outer conical wall, said member being immersed in water contained in a reservoir 43. Towards the front end of the double-acting piston there is an annular tongue 44 which enters the annular space between the walls of the member 41 to effect braking. The mandrel M is watercooled and consists of a tubular central core 24 provided on the outside with a series of longitudinal grooves 45. Surrounding the core is a sleeve 46 closed at one end by a base 47 spaced from the end of the core 24. The bore of the core communicates with a conduit 49 provided in the front end of the double-acting piston, said conduit terminating at the level of the annular tongue 44 in an injector 54. Cooling water is supplied from the reservoir 43 through holes 51 in the annular tongue 44 and a circle of holes 52 in the front end of the piston 20. The piston 20 constitutes an air reservoir which is fed on the working and return strokes of the piston by the cylinder 22 by means of a non- return valve 53 in the piston head. The compressed air in the piston escapes through the injector 54 and produces an intermittent supply of air and water which traverses the conduits 49, 48 and 45 and discharges through holes 55 in the mandrel holder 23. The synchronization of the cam-shafts 27 and 38 with the rolls of the mill may be effected mechanically, electrically, by optical-electrical means or electromagnetically. A mechanical synchronizing system comprises a motor 60, Fig. 6, which drives the rolls 61 by means of a shaft 62, gearing 63 and roll shafts 64. The cam-shaft 27, which controls the valves a, a<SP>1</SP> and b, b<SP>1</SP> is driven from the shaft 62 by bevel gearing 65, 66 on shafts 69, 70 respectively via a differential device 73, the intermediate wheel 71 of which is rotatable about the axis of the shafts 69, 70 by a handle 72 and adjustment of the intermediate wheel 71 effects the synchronization.