| 摘要 |
600,046. Stamping. BRITISH CELANESE, Ltd. Sept. 19, 1945, No. 24246. Convention date, Sept. 20, 1944. [Class 83 (iv)] [Also in Groups V and XVI] In a stamping-press the former 43 is operated by a cam 13 which has a dwell arranged to bring the former substantially to rest at the moment when it comes in contact with the sheet material being shaped. Preferably, the cam gives the former first a uniform acceleration and then a uniform deceleration as it approaches the sheet ; after the former is brought to rest in contact with the sheet it is advanced to shape the article, arrested again, and then advanced slightly to cut off the shaped article. A strip 33 of sheet stock is drawn intermittently, by means of the rollers 93, 95, through the heater 9 and across the lower die 22. At each pause, the plate 35 descends to hold the strip down and the former 43 then descends to punch out an article 34, pauses, and then descends further so that the article is cut off by the shoulder 46. A knock-out pin 71 then detaches the article from the former. The members 93, 95, 35, 43 and 69 are all operated by cams on the shaft 16 which is driven by the chain 128. The roller 93, which drives the roller 95 through gears, is driven intermittently, by means of a free-wheel, through linkage, by the cam 15, the free-wheel being moved in the' idling direction by the spring 117. The linkage is adjustable so that the movement of the sheet 33 for each revolution of the shaft 16 may be varied, The rollers may be turned manually by the wheel 125 and may be separated (against the pressure of the spring device 102) to thread in or release the strip, by the lever 126. The hold-down plate 35 is depressed by the cam 12 acting through the follower roller 64 and lever 65 on the adjustable rods 58, and raised by the springs 63<SP>1</SP>. The hold-down plate may also be operated manually by means of the handle 67. The former 43 is lowered by the cam 13, acting through the follower roller 53, and raised. by the springs 54. The position of the former 43 may be adjusted by means of the nut 51. The knock-out pin 71 is lowered, through levers, by the cam 14 and returned by the spring 74. The lower die 22 is heated by fluid circulating in the conduit 31, and the formed articles pass through a cooling box 26 which is cooled by fluid circulating in the conduit 32. The press described is for shaping articles from a sheet of plastic material having a basic of a thermoplastic material such as a cellulose derivative or a synthetic resin, but the invention may also be applied to presses for working sheet metal. Specification 509,785, [Group XVI], is referred to. |
