Patent GB-1130247-A (GB)
Title: Large corrugator
Inventor: HOMFELDT BRANSFORD RICHARD
IPC: B21D15/10
Filed: 1967-07-07
Abstract: 1,130,247. Corrugating tubes. CALUMET & HECLA Inc. 7 July, 1967, No. 31318/67. Headings B3E and B3Q.  A tube convoluting apparatus comprises a frame, partial-convolution forming means including a mandrel, carriage means movable reciprocally relative to the frame axially of the mandrel, first and second forming means mounted on the frame and carriage respectively and co-operable to complete the formation of a convolution, said first and second means each including tri-segmented means, each segment being shiftable laterally of the mandrel from a closed position closely adjacent the mandrel to an open position spaced therefrom by a distance greater than the height of the convolution and including stop means for arresting the trisegmental means in a closed position concentric with the workpiece and mechanical locking means for maintaining the tri-segmented means in closed position during a convolution-forming operation. The tube 10 is placed over a mandrel which includes a stationary ring 18, an elastomeric ring 16 and a tubular member 20 which is movable axially to compress the ring and form a bulge 10a in the tube. The axial length of the bulge is determined by two dies 12 and 14, each of tri-segmented construction. The tubular member 20 is raised to relieve the pressure on the ring 16 and the upper die 12 then descends to form the bulge to a convolution 10b, Fig. 12, and to move the tube downwards so that the convolution is opposite a recess 14a in the lower die, Fig. 14, the segments of which have been retracted radially outwards. The die 14 is then closed, Fig. 16, in readiness to start the formation of another convolution. The tube is clamped relative to the tubular member 20, when required, by an inflatable tube 270. The complete machine shown in Fig. 1 consists of a lower table 40 standing on feet 38 and connected by uprights 32 to a canopy 43. Three short vertical guides 44 position a carriage 36 which comprises three posts 46 which engage the guides 44 and are connected at their lower ends by a three-armed baseplate 50 and at their upper ends by a ring member 48. The carriage is reciprocated by three hydraulic cylinders 55. The construction of the upper and lower dies is similar and only the lower dies will be described. The lower die is formed in three sections each mounted on a radially movable slide 56 guided by surfaces 62 and 66 and reciprocated by an hydraulic cylinder (68), Fig. 5 (not shown). The inward movement of each slide is limited by an abutment (80a) on an abutment ring 80, Fig. 4. Each slide is locked against its abutment during the forming operation by a part-circular cam 86, which is rotated by an hydraulic cylinder and crank arm. The distance between the dies at the end of the downward stroke of the upper die, which forms the convolution, is determined by spacer blocks (104 and 106), Fig. 5 (not shown), on opposing faces of the lower and upper dies respectively. The blocks are aligned when the dies are closed, an are out of alignment when the lower die is opened, in order to allow the upper die to descend to carry the convolution downwards as shown in Fig. 14. The downward movement of the carriage during this latter stroke is limited by three stops 116 each consisting of a threaded pin rotatable in a sleeve 118 by worm-gearing 124, 126. All three stop pins are operated simultaneously by a hand-wheel 142. Three stops 150 limit the upward movement of the carriage, to the position shown in Fig. 10. The stops are similarly constructed and are operated by a hand-wheel 168. The mandrel structure for guiding the tube blank and pressurizing the elastomer ring 16 comprises a guide shaft 186 on which slides the piston of an hydraulic cylinder 182. The lower end of the shaft screws into a tube 206, Fig. 6a, which projects below the lower table 40 and carries lock-nuts 208 which support the rings 18 and 16. The tubular member 20 is secured to a tube 244 which is fixed to the lower end of the piston of the cylinder 204. The downward stroke of the piston and hence the initial bulging of the tube, as shown in Fig. 10, is controlled by a stop collar (280), Fig. 6 (not shown), fixed on the piston. The collar abuts an externally threaded sleeve 284 which is rotatable in an extension 204 of the cylinder 182 through gearing rotated by a hand wheel 288.