GB844144A - Grinding device for rotary cutter machines - Google Patents

Abstract

844,144. Grinding. KÍRBER, K. Nov. 21, 1958 [Feb. 27, 1958], No. 37521/58. Class 60. A grinding device for attachment to or forming part of a tobacco or fibrous material cutting machine having a series of rotating cutter blades 5, Fig. 1, comprises a grinding wheel 9 mounted in a pivoted carrier 7 to provide arcuate motion in a plane tangential to the pitch circle 4 of the cutter blades, the grinding wheel having an effective diameter exceeding the chord height of the arc of grinding wheel movement in grinding contact with the cutters. The carrier 7, supported by a spindle 8 adjustably mounted in a bearing 6 in the machine frame 1, is swung through its arc of movement by a reversible motor 11, Fig. 2, driving through a worm and wheel 12, 13, reversal of motion being effected by contacts located at 7<SP>1</SP>, 7<SP>11</SP>. A motor 14 drives the cupped grinding wheel 9, the grinding contact being maintained by known means for advancing the spindle 8 progressively to compensate for wear. A trueing diamond 17 is adjustably secured in a holder 16. A plurality of grinding wheels carried by separate arms, angularly spaced by the angle of sweep of a single-armed device, may be employed, the motor 11 in this embodiment driving rotationally, instead of oscillating, the grinding wheel carriers 7, and the motor 14. being provided with multiple belt and pulley drives for the grinding wheels. In the construction shown in Fig. 3, a toothed disc 26, rotatable about the axis of the grinding wheel driving motor shaft within an outer casing 27 secured to the frame of the tobacco or the like cutter, forms the carrier for a plurality of grinding wheels 31 each sweeping a grinding arc the height of chord of which is exceeded by the diameter of each wheel. The carrier disc 26 is driven by a pinion fixed to a shaft driven through skew gearing from the cutter-drum shaft. The driving spindle 30 of each grinding wheel 31 is progressively advanced towards the cutter blades 46 by means of an externally threaded ring 33 mounted on the spindle and contacting a collar 35. The ring 33 is held against rotation relative to the spindle 30 by pins 36, but is caused to move axially by an internally threaded worm wheel 37 which engages the externally threaded ring, the wheel 37 being given a small increment of rotation at each revolution of the disc 26 by means of a worm 38 which is itself intermittently turned by a ratchet-lever 41 actuated by contacting a fixed cam 42. The cutter blades 46 may be provided with known means for progressive advance during rotation, such as worm-andwheel 51, 52, to maintain constant the cutter pitch circle 5, and a trueing diamond 45 is provided in a holder 44.