Patent GB-190414755-A (GB)
Title: Improvements in Machines for Stamping and Punching Leather, Cardboard, and other Material.
Inventor: GROS HERMANN CARL
Filed: 1904-06-30
Granted: 1905-06-29
Abstract: 14,755. Gros, H. C. June 30. Cutting - machines for leather, cardboard, &c.- Relates to cutting - out presses provided with a movable die. To prevent accidents arising through the band &c. of the operator being caught between the head of the machine and the die, means are provided whereby the head and die are brought together gently through the operation of a treadle &c., before the power mechanism is brought into operation for forcing the die through the material. The die 28, Fig. 1, being placed on the material 29, the treadle is pressed down, which actuates, through the connecting-rod 10 and the bell-crank lever 9, a rack 8, thus causing, by means of the pinion 7 and screwed spindle 6, the ram 5 and with it the die-block 4 and die 28 to move up until the die is in contact with the verticallyadjustable head 1. The power mechanism is now brought into gear by operating the lever 25. The lever 25 actuates the clutch lever 21, the extremity of the treadle entering the square hole 27, Figs. 1 and 3 in this lever. The clutch comprises a spring catch 19 which is mounted on the boss 20 on the shaft and, when the lever 21 is moved to the left, engages in a notch 26 or 26<1> on the power-driven flywheel. After one revolution of the shaft 4 a projection 22 on the lever 21 disengages the catch 19. The shaft 14 carries the cam 13 which presses up the ram 5, 51, and so punches the material. In Fig. 4, the head 1 is shown provided with a spring pressure plate 30, so that the machine may be used for operating on material of varying thickness without re-adjustment. In the arrangement shown in Fig. 11, the head is brought down upon the ram by means of the treadle and a pair of toggle-levers in the head, the main pressure being produced by a cam acting on the ram. The flywheel &c. drives the main shaft through a clutch comprising a longitudinally-sliding disc 38, which is normally held out of action by a spring stop 36. When the disc is released by operating the treadle, projections thereon engage with corresponding projections on the flywheel, and, when the treadle is released, the stop 36 engages a-helical cam with the disc and withdraws it against the action of its spring. Figs. 7 and 9 show heads which may be moved aside to allow of free access to the die. In the arrangement shown in Fig. 9, when the treadle is in its highest position, the head 1 is in the inclined position shown in dotted lines, and, on the treadle being depressed, the head 1 is brought into the vertical position shown by means of a connectlng-rod 24 and lever 9. The turning movement of the head 1 is limited by a stop, after which the lever 9 straightens the toggle-levers 1<a>, 1<b> and moves the head slightly downward and more firmly in contact with the die. The main pressure may now be brought into operation as before, or, as shown in Fig. 9, by a further operation of the treadle. While the head is being turned into a vertical position &c., the pin 11<b> moves in the slot 11#, and, during the latter part of the depression of the treadle, the rod 11<d> operates a clutch and brings the power mechanism into operation.