Patent GB-767793-A (GB)
Title: Improvements in or relating to forming flanged openings or nipples in metal pipes
IPC: B21C37/29
Filed: 1955-01-27
Abstract: 767,793. Flanging; punching. HUET, A. Jan. 27, 1955 [Feb. 4, 1954], No. 2552/55. Class 83 (4). Apparatus for producing nipples on a pipe, e.g. a heatexchanger header comprises an hydraulic jack and punch for insertion into the pipe and a die for placing outside the pipe, the punch and die set forming a co-operative assembly with a cradle which supports the pipe and can be moved along the whole length of the latter and in which a holder for the die is provided with two arc - shaped braces which press simultaneously with the die against the pipe on each side of the working area and opposite that portion of the pipe which is supported by the cradle. The apparatus comprises a wheeled carriage a running on rails b and at one end of the carriage a base-plate c carries the cradle unit which supports pipe e and the die l which is clamped on the outside of the pipe. At the other end of the carriage a support carries an hydraulic jack f carried by two steel bars d<SP>1</SP>, d<SP>2</SP>, said jack operating a punch g. The cradle consists of three supports h<SP>1</SP>, h<SP>2</SP>, h<SP>3</SP> adjustably mounted on a platform h<SP>4</SP> attached to the base-plate c. On each side of the pipe columns j<SP>1</SP>, j<SP>2</SP> on the base-plate slidably support a crosshead k which carries the die l and also a plate m - on which is adjustably mounted two arc-shaped members n<SP>1</SP>, n<SP>2</SP> which are locked in position by keys o<SP>1</SP>, o<SP>2</SP> when positioned on the pipe opposite to and one on each side of the cradle h<SP>1</SP>, h<SP>2</SP>, h<SP>3</SP>. The jack is prevented from tilting during the forming operation by means of a pilot pin p fitted on a plate p<SP>1</SP> adjustably mounted on the member m and engageable with a block q slidable between the bars d<SP>1</SP>, d<SP>2</SP> of the jack f. The punch and die set is automatically accurately positioned on the pipe by means of a metal band r mounted on the column j<SP>2</SP> and having at its end a ball r<SP>1</SP> which engages in the drilled holes or indentations made in the pipe at the places where the nipples are to be formed. Such engagement of the ball closes an electric contact r<SP>2</SP> which switches on a warning light r<SP>3</SP>. Chocks w are then applied to the carriage wheels by operating a lever v or the contact r<SP>2</SP> may automatically operate means for applying the chocks. When the pipe, supported on the cradle, is accurately aligned in the apparatus, the area of the pipe in which the nipple is to be produced is heated and external jacks (not shown) lower the cross-head to press the members n<SP>1</SP>, n<SP>2</SP> and the die against the pipe to clamp it in position and the pilot pin p engages the block q. The jack is now operated and the punch forms the nipple. The operation can be repeated using punches of increasing size if necessary. After a first nipple has been formed close to the end of the pipe, the pilot pin is inserted into the first nipple to ensure correct positioning and so forth. Specification 754,431 is referred to.