Patent GB-1124088-A (GB)
Title: Production machine
Inventor: ANDREWS PETER GEOFFREY
IPC: B21D28/28
Filed: 1966-01-19
Abstract: 1,124,088. Bending cutters. WALKER MFG. CO. 19 Jan., 1966, No. 2481/66. Headings B3J and B3W. An apparatus for forming louvres in a tube includes a mandrel 68 insertible in the tube and adapted to expand to form louvres in the tube, a die 150 adjacent the mandrel and encircling the tube and having longitudinally extending through-slots into which the material of the tube is deformed, the deformed portions subsequently moving axially freely through the slots and means for moving the tube longitudinally relative to the mandrel. Cutter construction and operation, Fig. 3.-The mandrel 68 is hollow and at its right-hand end has a plurality of longitudinally extending radial slots each of which contains an arm 86 at one end of which are the outwardly projecting louvring teeth 90. The other ends of the arms are retained by a ring 96 and have semi-circular pivot ends 92. A rod 78 passes through the mandrel and carries an expander cone 112 which engages angled faces on the inside surfaces of the arms 86. The left-hand end of the rod is connected to the piston of a pneumatic cylinder 34. The die 150 is clamped in a bracket 142, 148 fixed to the frame of the apparatus. Tube clamping and indexing device.-The tube is clamped on to the mandrel by a plurality of dogs 174 mounted around a shaft 172, which passes through and is fixed relative to an hydraulic cylinder 162. The piston 184 of the cylinder surrounds the shaft 172 and carries on its piston-rod a sleeve 182 which engages the outside edges of the dogs and causes them to contract on to the tube. A spring-loaded ejector shaft 210 passes through the shaft 172 and carries an ejector cup 212. The complete assembly described above is attached to the piston-rod of an hydraulic cylinder 234, by which it is reciprocated longitudinally of the mandrel. Tube feeding mechanism, Fig. 10.-Tubes to be processed are loaded into a magazine 11 having guide rails 258, 280 which engage the ends of the tubes and are adjustable to suit tubes of various lengths. The tubes are released singly by an escapement 312 and roll into a V-shaped trough, which is raised by an hydraulic cylinder 284 to align the tube with the mandrel. Control system.-The cylinder 34 is controlled by a valve operated by a cam 118 and a link 136 and also by a valve operated by a solenoid S6. The valves controlling the cylinders 160, 234 and 284 are all solenoid-operated, the solenoids being controlled by limit switches LS1 to LS6 which are actuated by the movements of the mechanism. Operation.-Initially all the cylinders have their pistons retracted. A starter button energizes solenoid S 1  and causes the cylinder 284 to raise the V-shaped trough which at the end of its travel operates a limit switch LS 1 . Solenoid S 2  is energized and causes actuation of cylinder 246 to move the assembly 160 a few inches to the left until a lever 354 attached to the assembly operates switch LS 2  which de-energizes solenoid S 2  and stops the left-ward movement of tho assembly 160. Simultaneously solenoid S 3  causes the piston of assembly 160 to move to the right to open the tube clamping dogs, and the movement of the cylinder 284 is reversed to lower the trough, which at the end of its movement operates switch LS 3  to reenergize solenoid S 2  and re-start the left-ward movement of the assembly 160. During this movement the lever 354 closes switch LS 4 , in the circuit of a solenoid S 6 , which controls a valve in the circuit of the pneumatic cylinder 34. The circuit is also controlled by the valve operated by the cam 118, so that so long as the switch LS 4  remains closed the cylinder operates cyclically due to the rotation of the cam. The pump 254 which supplies hydraulic fluid to the cylinder 234 is driven from the cam-shaft 120 so that the movement of the cylinder 234 is synchronized with the operation of the louvring cutters. The cutting action and the incremental movement of the cylinder 234 continue until the lever 354 dis-engages the switch LS 4  which stops the cutting action, but the cylinder 234 continues to move until the lever 354 actuates switch LS 6  which de-energizes solenoids S 5  and S 3 , causing the cylinder 234 to retract and the tube clamping dogs to open, enabling the rod 210 to eject the finished tube.