Patent GB-1427345-A (GB)
Title: Dosing and weighing of cut tobacco
IPC: A24C5/00
Filed: 1972-08-09
Abstract: 1427345 Metering tobacco DOUWE EGBERTS TABAKSMAATSCHAPPIJ BV 8 Aug 1973 [9 Aug 1972 25 Oct 1972] 37114/72 and 49199/72 Heading A2C [Also in Divisions B8 and G1] An apparatus for weighing out a predetermined quantity of long fibre tobacco comprises means for separating the long and short fibres in a tangled mass of tobacco, means for metering a first quantity, less than the predetermined quantity, of tangled long fibres, and means for metering a second quantity of disentangled long fibres to make up the predetermined quantity. A tangled mass of tobacco is fed to a hopper 1 and, pushed against a rotating drum 3 by a conveyor belt 2. Drum 3 has a series of bars 7, each bar carrying needles 8 protruding through holes in the circumference of the drum. The bars 7 are mounted on discs 9 by arms 6 and engage stationary camming surfaces 5 shaped such that as the needles pass through the tangled mass in hopper 1 they are gradually pushed out to pick up tufts of long fibres, the size of the tufts being limited by a wiper roll 10. On further rotation of drum 3, the needles retract and the tufts fall into a chute 11. The short fibres pass between the belt 2 and drum 3. The tufts from chute 11 fall partly into a shaft 12 and partly onto conveyors 13 which can run in either direction so as to drop the tufts into shaft 12 or into shaft 21. The tufts from shaft 12 fall into a compacting device consisting of four converging conveyor belts 15 which produce a compacted continuous strand of tobacco. To meter the first quantity, the belts 15 are advanced a predetermined distance, combs 17, 17' inserted in the strand, and comb 17 is moved downwardly, the disengaged tobacco falling into one of the weighing hoppers 18. Tobacco tufts from shaft 21 fall onto a conveyor 22 which pushes them against a needle drum 23 which pulls fibres from the tufts to form a fleece on the drum whose thickness is limited by a needle drum 24. A high speed drum 26 strips the fibres from drum 23, and the fibres fall into the weighing hopper 18. When the predetermined quantity of fibres is reached flap 27 closes the drums stop rotating and the weighing hopper opens to dispense the tobacco. The direction of motion of conveyor belts 13 is controlled by an ultra sonic level sensing device above conveyor 22. An ultra sonic level sensing device controls rotation of drum 3. When the apparatus is to be stopped, needles 20 enter the tobacco in shaft 12 to support it. The distance travelled by the belts 15 or the distance between the belts is adjustable, and adjustment may be effected according to the deviation of the weights of a plurality of successively disengaged lengths from a desired weight. A predetermined volume of short fibres may be added to each predetermined quantity of long fibres by the device shown in Figure 3. This comprises a series of cylinders 32 having permeable bases 33 where position may be adjusted. The cylinders 32 are mounted in a rotating disc 32 and the bases 33 are first placed in communication with a suction channel 36 to fill the cylinders and then with a pressure source 36' to empty the cylinders.