GB769615A - Improvements in or relating to a method of and apparatus for rolling metal tubes - Google Patents

Abstract

769,615. Rolling. BENGTSSON, F. G. March 29, 1955 [March 29, 1954], No. 9094/55. Class 83 (4). In a method of cold rolling tubes by taper-grooved rolls 62, Fig. 1, reciprocating over the work while it is intermittently fed step by step, the rolls are simultaneously rotated about the axis of the work. The rolls 62 are mounted in a carrier 32 which is coupled by a tie rod 33 to a reciprocating cross-head 27 sliding in guides 30, Fig. 2, and actuated through connecting rods 23 coupled to crankpins 21 on driven gears 14. The carrier 32 has arms 37 which are slidable on guides 38 in a frame 39 which is rotatable on bearings 42, 43 and driven from a shaft 35 through a chain 47 to rotate the carrier 32 about the axis of the work. Thrust bearings on the tie rod 33 permit relative rotation between the carrier 32 and the cross-head 27. The rolls 62 are also oscillated during the reciprocating movement by spur gears 76 on each roll shaft which engage toothed racks 77 attached to the rotary frame 39. Coolant may be supplied to the rolls from a conduit 59 connected to the cross-head 27, the coolant passing through the hollow tie-rod 33. Each roll 62 is mounted on a pin 64, Fig. 4, having conical portions 67, 68 at each end which are eccentric to the axes of the pin to permit adjustment of the roll after refacing. Nuts 72, 73 at each end clamp the pin within the carrier 32 and permit ready release of the roll by withdrawal of the pin. A pair of mandrels 53 for carrying the work is mounted on a transversely movable bridge 56 so that either mandrel may be brought into position for the rolling operation while the other is moved to one side and lifted by an hydraulic ram 57 to an inclined position at which it can be supplied with a new workpiece from a shoot 50. The bridge 56 is slidable along guides by hydraulic rams 97 to insert the mandrels 53 in the required position between the rolls. The work is fed intermittently over the mandrel 53 by a pair of reciprocating gripper devices 48, 49 placed in front of and behind the roll carrier so that the work is engaged by one or the other throughout the operation. Each device comprises clamping members 106, 107, Fig. 7, on a carrier 104 which is reciprocated horizontally by a cam-operated vertical push rod 115 carrying a roller 114a engaging in a slotted disc 111 which can be turned to any required angle by a hand wheel 114 to adjust the length of feed stroke. The lower fixed jaw 106 is adjustable by a screw 105 and the upper jaw 107 is normally actuated by a spring 109 to grip the work during the feeding stroke. During the return stroke the jaw 107 is released by cam-operated push rod 119 which lifts the arm 110 carrying the jaw 107.