Abstract: A tobacco shredding machine wherein the cutting edges of orbiting shredding knives are sharpened by the undulate annular surface of a grinding wheel which is reciprocated forwardly and backwards in parallelism with the axis of the holder for the knives and is retracted from the circular path of the cutting edges during each return stroke of its support. The speed of forward movement of the support while the grinding wheel sharpens the cutting edges is such that the support covers during each revolution of the holder a distance which equals or is a whole multiple of the width of an undulation on the grinding surface. The axes of the grinding wheel and of the holder for the knives are located in a common plane.

Abstract: The undulate cutting edges of knives on a rotary knife holder in a tobacco shredding machine are ground by a grinding wheel whose profile is complementary to that of the cutting edges and which is moved stepwise in parallelism with the axis of the holder and thereupon radially or tangentially of the holder toward and from engagement with successive portions of the knives so that the grinding wheel treats a portion of a previously treated section and an untreated section of each knife while it is held close to the path of orbital movement of the knives. An advancing mechanism is provided to shift the grinding wheel stepwise in parallelism with the axis of the holder, and a moving mechanism is provided to displace the grinding wheel toward and away from the path of orbital movement of the knives during each interval between successive advances.

Abstract: Apparatus for moving the knives relative to their rotary holder in a tobacco cutting machine has a crankshaft which is rotatable and is rotated once during several successive revolutions of the holder. The crankshaft is the input element of a step-down transmission whose output element is a ring gear meshing with pinions for transmission of motion to discrete displacing units, one for each knife. The ring gear is rotated at intervals by a gear which is coaxial with a freewheel. The latter is rocked back and forth by a lever which is pivoted by the crank pin of the crankshaft by way of a rod-like connector. One end portion of the connector is coupled to the lever by an adjusting device which can change the extent of pivotal movement of the lever and hence the extent of rotation of the ring gear whenever the lever is pivoted in one of two directions.

Abstract: A machine for shredding tobacco wherein the rear portion of the upper reach of the lower chain conveyor of the conveyor system which converts a continuous stream of tobacco particles into a continuous cake is located below the open lower end of an upright duct serving to deliver tobacco to the conveyor system. The rear wall of the duct is oscillated by an orbiting eccentric pin through the medium of a rod, a lever and a link, the latter being rigidly connected with the upper portion of the rear wall and being pivotable about the axis of a horizontal shaft disposed substantially centrally and transversely of the upper end of the duct so that a vertical plane which includes such axis intersects the upper reach of the lower chain conveyor in front of the forwardly curved spade-like lower portion of the rear wall.

Abstract: A tobacco shredding apparatus wherein a relatively small upright duct receives tobacco from a large magazine. A system of tobacco compacting chains draws tobacco from the lower part of the duct and feeds the resulting cake into the path of orbiting shredding knives. The chains and the knives are driven by a first variable-speed motor. A conveyor which is driven by a second variable-speed motor transfers tobacco from the magazine into the duct. The volume of tobacco in the duct is monitored by a first set of photocells whose signals are used to regulate the speed of the second motor so as to maintain the volume of tobacco in the duct within a first range. The volume of tobacco in the magazine is monitored by a second set of photocells whose signals are utilized to regulate the speed of the first motor so as to maintain the volume of tobacco in the magazine within a second range. The capacity of the magazine is between five and ten times the capacity of the duct.

Abstract: A tobacco cutting machine wherein two endless chain conveyors define a horizontal channel of diminishing height for conversion of tobacco into a cake whose leader advances into the range of and is shredded by orbiting knives. The lower chain conveyor extends rearwardly beyond the upper chain conveyor and is located below the lower end of a vertical passage which is defined by an upright duct having several mobile walls which flank different portions of the passage and are pivotably mounted in the housing of the cutting machine. One of the mobile walls is located immediately above the rearwardly extending portion of the lower chain conveyor and is oscillated at a high frequency by an eccentric drive. Another mobile wall of the duct is located above the one mobile wall or directly above the rear end of the upper chain conveyor and is oscillated by a second eccentric drive at a lower frequency but through larger angles.

Abstract: The chains which condense and advance a continuous cake of compacted tobacco into the range of orbiting knives in a tobacco shredding machine are driven by a reversible prime mover independently of the motor which drives the knives. When the movement of the prime mover in a direction to advance the tobacco cake into the range of the knives is interrupted, the prime mover is automatically started in reverse so that the chains retract the leader of the cake from the range of orbiting knives and thus prevent further comminution and eventual overheating and combustion of tobacco. The operation in reverse is terminated by a time-delay device when the leader of the cake is retracted from the range of orbiting knives to an extent which insures that automatic expansion of the leader toward the knives does not suffice to permit any contact between the cake and the orbiting knives while the chains are not driven in a direction to move the cake toward the knives.