| 摘要 |
<p>1,198,694. Flying shears. A. BORZYM. 8 Aug., 1967 [1 Sept., 1966], No. 36443/67. Heading B3W. A flying shear 20 for cutting travelling work, e.g. metal tubing 16, comprises a carriage 22 which is reciprocated by a piston cylinder assembly 75 whose piston-rod 77 is coupled, 78, to a bar 56 on which speed limiting means operate to limit the speed of the carriage. The carriage runs on tracks 28 carried by the ram 30 of the shear and includes a chuck to grip the tube 16 during shearing. The piston cylinder assembly is preferably pneumatic and the piston-rod 77 is connected to the carriage through the bar 56 and linkage 50-55, and a rod 36. The arms 50, 54 of the linkage are pivoted at 52 and the pivot pin has rollers 58 which run on a surface 60 and between guides 172, 174 on each side of the casing. When the piston 79 is moved leftwards the linkage acts as an accelerator for the carriage. The speed of the carriage during the shearing is controlled by a pair of rollers 86, 87 which are urged against the rod 56 by a pneumatic piston cylinder assembly 100 during the shearing stroke only. The rod 56 has tapered ends 108 so that the rollers can be driven continuously by a motor 112 whose speed is accurately controlled, 113. Spacers are provided between the rollers chocks so that the minimum separation is greater than the width of the end portions of the bar. In operation with the carriage stationary at the right, the moving tube 16 from a tube mill 15 strikes a flag 120 fastened to a rod 122 which slides in guides 123, 124 horizontally parallel with the tube. The rod 122 is moved leftwards causing an adjustable abutment 126 to engage a latch 128 on a rod 130 pivoted at 132. Movement of the rod 130 is transmitted through linkages to pivot a latch member (142), Fig. 8 (not shown), out of engagement with a step 57 on the bar 56. The latch 142 is held out of engagement by a second latch (145). Air is admitted to the cylinder 75 prior to the release of the latch 142 to urge the piston leftwards. Simultaneously air is admitted to the cylinder 100 to urge the rollers together. The rod 56 is gripped by the rollers to accurately control the speed of the carriage. When the carriage reaches the speed of the tubing it trips a switch (71), Fig. 2a (not shown), initiating a cycle of the ram. After the shearing the carriage trips a switch (74) to exhaust the cylinders and apply air to the left end of cylinder 79 to return the carriage. No air is applied to the cylinder 100 on the return stroke so the rollers do not grip the rod 56. The return movement of the carriage is stopped by an hydraulic buffer 32. The cut-off tubing is ejected under gravity down a shoot (169), Fig. 2b (not shown). The linkage 50-54 and the speed-limiting rollers are housed in a bath of oil 40 and oil-seals 44 are provided where the rods pass through the walls.</p> |
