GB402958A - Improvements in or relating to guillotine paper-cutting machinery and guards therefor - Google Patents

Abstract

402,958. Machinery guards. CHAMBERLAIN, S. B., c/o St. Luke's Printing Works, Old Street, London. Feb. 10,1933, Nos. 4104 and 5548. [Class 80 (iv).] A guillotine paper-cutting machine having a rising and falling grid or guard to protect the operator, is provided with (a) means to prevent actuation of the knife until the guard is down in operative position, and also to prevent raising of the guard until the driving clutch is out and the driving shaft has ceased to rotate ; (b) means for preventing the knife from overrunning after a. down and up stroke ; and (c) means for holding the severed portion of the pile of paper as it is pushed by the knife. The guard 18 is mounted on links 19, 21 and the bottom bar 20 is connected at one end to a crank lever 25 which is adjustably connected to a locking bar 27 ; the end of the bar 27 can slide in a slot 32 in a stop plate 31 on the striking-on lever 30. When the clutch is out and the clutchlever 17 is held in the catch 29 on the lever 30, the bar 27 registers with the slot 32 and the guard can be swung down, thus withdrawing the end of the bar 27 from the plate 31. The striking-on lever 30 can then be turned by hand to release the lever 17, but the guard cannot be raised as the bar 27 would be stopped by the plate 31. When the cut is completed, the lever 17 is reset under the catch 29, and the slot 32 and bar 27 again register ; the guard can then be raised. To prevent the guard from being raised if the driving shaft 15 is still running, a pawl 43 on the bar 27 is turned into engagement with a rack 46 by a vane 45 which is deflected by spokes 48 on a small wheel 47 driven by a cord 49 from the shaft 15. The pawl and vane are normally held up by a spring, and if the shaft 15 is stationary, the vane can slide between the spokes 48. To prevent the knife from overrunning, a pivoted strut 51 operated by a link 52a is brought under the knife 13 when the guard is raised, and is tilted out of the path of the knife when the guard is lowered. The upper part of the strut is provided with a crutch 52 and rubber buffer 55; and the lower end is curved to bear on a pillar 53. To hold the severed portion of the pile of paper, spring-controlled vertical rods 37 sliding in guides 36 on a bar 33 carry wheels 39 which bear on the pile, and the rods are raised by a rail 41 mounted on the knife carrier and engaging under tappet rollers 40.