Patent GB-1382277-A (GB)
Title: Method and apparatus for handling tobacco
IPC: A24C5/39
Filed: 1972-02-24
Abstract: 1382277 Tobacco treatment apparatus HA UNI-WERKE KORBER & CO KG 24 Feb 1972 [13 March 1971] 8675/72 Heading A2C [Also in Divisions B8 and G3] In a plant in which tobacco is conveyed between treatment stations the flow per unit time at one section of the conveyor is automatically kept at an adjustable reference value, and at least one treatment station downstream of said section is also controlled in dependence on the same reference value and at least one station upstream is controlled in dependence upon the amount of tobacco between the said section and the said upstream station. The object is to prevent the necessity for individual adjustment at each station when the flow rate is changed, although provision is made for such adjustment. Control of flow. Conveyor section 7 comprises a pivoted portion 77 supported by a spring 74. Deflections move a potentiometer 78 whose output is multiplied with that from a tachogenerator 81 for comparison with the reference value from potentiometer 86. The difference regulates the speed of a motor 82 driving the conveyor section and its feed belt 62. Control of upstream station. The level of tobacco in a temporary store 63 is detected by photo-electric cells 67..69 whose output constitutes the reference value for an automatic system controlling the speed of a motor 26d driving a cutter 11d. The reference is compared with a tacho. signal and a signal indicative of the gap between adjustable belts feeding the cutter. Four cutters are used, only one being automatically controlled. They are fed from a conveyor which re-circulates a surplus, which is weighed by a belt weigher, the signal from this being combined with a further reference and a signal from a tachogenerator coupled to a motor driving a feed belt (which is thereby controlled) supplying the conveyor from a hopper (Fig. 2, not shown). Downstream stations. The first of these is an arrangement for adding rib tobacco to the main stream. It comprises a supply and constant flow system similar to that for the main stream, the reference value for the con- Stant flow device being that for the main stream supplied via a network which delays the signal by an amount corresponding to the travel time of the tobacco. (Arrangement 13, Fig. 1, not shown). The next treatment station is a dryer (Fig. 4, not shown). Tobacco is fed through a revolving drum into which warm air is blown, the amount being regulated by a valve (137) in response to the flow reference signal (on 88) further delayed and a measurement of the moisture in the incoming tobacco. The drum is also heated by steam pipes, the steam valve being regulated by the difference between the moisture content of the outgoing tobacco and an independent reference, which thus controls the dryness automatically. Next, sauce or flavour is added (Fig. 5, not shown) by spraying, the spray pump motor speed being regulated by the delayed flow reference signal, an independent reference and a tacho. signal. Tobacco leaving this station is fed to a storage container (182), the outflow from which is regulated by a belt (183) driven by a motor, controlled in the same way as the sauce pump motor. In an alternative embodiment (Fig. 7, not shown) the flow reference is supplied directly to the cutter in addition to the other signals.