Patent GB-297066-A (GB)
Title: Improvements in or relating to machines for the precision cutting of tobacco into flakes or shreds
IPC: A24B7/12
Filed: 1927-03-14
Abstract: 297,066. Imperial Tobacco Co., (of Great Britain & Ireland), Ltd., Thorn, W. S., and Humpage, T. March 14, 1927. Cutting tobacco.-Tobacco is compressed and fed through a mouthpiece to a rotating cutter the axis of which is arranged transversely to the mouthpiece. The tobacco leaves are carried from a hopper 1 by a conveyer band 2, the tension of which is adjustable, to the main feed belts 3, 4, passing over driving rolls 5, 5<a>, and provided with supporting plates 13, 14. The lower driving roll 5. together with the driving roller 10 for the conveyer 2 and the intermediate gear wheels 11, are carried in sliding blocks 8 that may be adjusted by screws 9. The driving rolls are driven from a power shaft 36 through a train of gearing 35, 38, 39, 41, 104, 105, 106. The speed of the belts may be altered by varying the gear wheels 35. Feed rollers may be substituted for the belts 3, 4. The tobacco, which is compressed by the belts converging, is fed into a mouthpiece having a fixed lower part provided with a sharp edge 31, such edge being preferably formed on a loose and adjustable strip, and a movable upper portion 16 that rises and falls in accordance with the varying thickness of the tobacco passing through the mouthpiece. The member 16 may take the form of a bridge-piece and carry the spindle of the upper feed roller 5<a>, being pivotally connected also to the member 14 which is secured at its rear end to a bracket carrying the spindle 27 of the upper rear feed roller 5. The member 16 is pressed downwards by springs 18 that may be adjusted by screws 20 operated from a handwheel 24. Springs 33 are fitted to take some of the pressure of the spring 18 off the screws 20. A scale may be fitted to indicate the pressure applied for a standard thickness of leaves. The rotary cutter 103 has one or more knives 42 and part of the surface generated by the revolution of the cutting edge of the knives coincides approximately with the front of the mouthpiece. The knives are clamped in position by a jaw 45, Fig. 7, mounted on a pivot 46 and actuated by an eccentric shaft 47 turned by a key. The knives, which am ground at a constant bevel, are positioned for clamping by a gauge 69, Fig. 11, provided with lugs 72 to bear against the back of the pivot 46 and with rollers 71 to engage the bevelled portion of each knife. To draw a knife up against the gauge an electromagnet 74, secured by a universal connection to a slide 75 and drawn forward by a spring 79, is energized and, being provided with recesses to engage the bevel of the knife, moves it into position for clamping. A hand-actuated clamp may be substituted for the electromagnet. The knives are positioned to give clearance behind the cut and the rotating member is cut away at 63 to provide a space into which the cut tobacco can move. To ensure the tobacco falling into the delivery trough 56 an air blast is directed from the interior of the cutter into the space 63, such air blast preferably acting shortly after each cutting operation. The cutter is mounted in brackets 51 movable in guides 55 by screws 58 and adapted to be secured in adjusted position by locking nuts 59. A guard may enclose the cutter. The bridge piece 16, instead of moving in straight guides in the machine, may be connected by arms to the shaft 50 of the cutter or mounted in curved guides so that it moves about the axis of the cutter as centre. The shaft of the cutter may be moved laterally while being rotated to give a draw-cutting action.