GB2160987A

GB2160987A - Conveyor apparatus for tobacco packers

Info

Publication number: GB2160987A
Application number: GB08515395A
Authority: GB
Inventors: Francis Beatty Fishburne
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-06-18
Filing date: 1985-06-18
Publication date: 1986-01-02
Also published as: IT1181692B; GB8515395D0; GB2160987B; IT8548236A0

Abstract

A first conveyor (1) carries tobacco from a redryer and deposits it onto a reversible second conveyor (2); the second conveyor is operated to feed the tobacco onto the input end of a variable- speed third conveyor (6) arranged to weigh the tobacco as the tobacco is deposited thereon; the third conveyor is operated at a slow rate until a predetermined weight of tobacco has been deposited thereon and then is shifted to a fast rate and the second conveyor is reversed to commence operation as holding conveyor; the third conveyor discharges onto a fourth conveyor (11) and upon completion discharge of the weighed quantity of tobacco the second conveyor is again reversed and begins again to feed its held tobacco as well as incoming tobacco from the first conveyor onto the now empty third conveyor, the third conveyor being returned to its slow rate simultaneously with reversal of the second conveyor; the above steps are then repeated for as many cycles as are required. <IMAGE>

Description

SPECIFICATION Conveyor apparatus for tobacco packers This invention relates to conveyors and particularly to an improved conveyor apparatus for use in feeding tobacco to a tobacco packer and a method for supplying and operating tobacco packers.

It has long been conventional in the tobacco industry to feed tobacco from a redryer to a packer which is operated to compact the tobacco into cases, bales or hogsheads. Redryers operate continuously and at a relatively high rate, and the packer must therefore be operated st such a rate as to satisfy the demands of the redryer output since it is not practical to shut the redryer down. Accordingly, packers of the vertically acting type have been developed which have relatively short cycle times on the order of 35 seconds in which the amount of tobacco required for a case, etc, is packed. Even so, the fact that the redryer delivers tobacco continuously while the packer operates in cycles and cannot accept tobacco while a cycle is in progress has causes problems in arriving at an efficient total operation.One prior art approach to solving such problems has been to employ a holding conveyor or conveyors to accept tobacco from the redryer during those periods when the packer cannot accept more tobacco.

However, prior art use of holding conveyors does not meet with favour in many factories, and there has been a continuing need for improvement.

According to the invention, a first conveyor is operated to carry tobacco from the redryer and deposit the tobacco continuously and at a substantially constant rate onto a reversible endless second conveyor; the second conveyor is operated in one direction to feed the tobacco onto the input end of an endless variable speed third conveyor constructed and arranged to weigh the tobacco as the tobacco is deposited thereon; the third conveyor is operated at a first relatively slow rate until a predetermined weight of tobacco has been deposited thereon the second conveyor, whereupon the third conveyor is shifted to a second relatively fast rate and the second conveyor is reversed to stop its feed to the third conveyor and commence operation as a holding conveyor, the third conveyor is operated at said second speed until the entire weighed quantity of tobacco has been discharged from the third conveyor onto a fourth conveyor arranged to supply tobacco to the packer, upon completion of discharge of the weighed quantity of tobacco from the third conveyor onto the fourth conveyor the second conveyor is again reversed and begins again to feed its held tobacco as well as incoming tobacco from the first conveyor onto the now empty third conveyor, the third conveyor being returned to its first relatively slow rate simultaneously with reversal of the second conveyors; the above steps are then repeated for as many cycles as are required for the time period of operation of the redryer and packer, the successive weighed quantities of tobacco received by the fourth conveyor from the third conveyor being separated on the fourth conveyor by intervals determined by the rates of operation of the conveyors; the packer being operated through one complete packing cycle during each such interval.

The following is a description of a specific embodiment of the invention, reference being made to the accompanying drawings in which: Figure 1 is a side elevational view of a conveyor system according to one embodiment of the invention; and Figures 22-2C are successive sequence diagrams illustrating operation of the system shown in Fig. 1.

As seen in Fig. 1, the invention employs a first endless belt conveyor 1 which is driven at a constant speed and delivers tobacco from the redryer (not shown) to a second endless belt conveyor 2. Conveyor 2 is reversible and is driven by a pressure fluid operated rotary motor 3 so that the speed at which the conveyor is driven depends upon the rate at which pressure fluid is supplied to motor 3.

Inclined upwardly, conveyor 2 is disposed with its lower end beneath the delivery end of conveyor 12. At its upper end, conveyor 2 is equipped with a chute 4 to receive tobacco in the event that, while operating to carry the tobacco to the right, as viewed, more tobacco is received than the conveyor can handle.

Conveyor 2 is rigidly supported by legs 5.

A third endless belt type conveyor 6 is located beneath conveyor 2 and is inclined similarly to conveyor 2, the lower end of conveyor 6 is located below and projects beyond the lower end of conveyor 2 so that, when conveyor 2 is operated to deliver tobacco to the left, as viewed, the delivered tobacco will fall upon the belt of conveyor 6 and be carried by that belt upwardly to the delivery end of conveyor 6. A curved deflector 7 is provided, as shown, at the receiving end of conveyor 6 to guide the tobacco as it falls from the lower end of conveyor 2.Conveyor 6 is supported by a frame comprising four legs 8 and a conventional load cell 9 is interposed between the lower end of each leg 8 and the supporting floor, so that conveyor 6 operates as a weighing conveyor, the load cells providing an electrical output signal, in conventional fashion, representative of the total weight of tobacco on the conveyor regardless of the distribution or location of the tobacco on the conveyor belt. Conveyor 6 is powered by a pressure fluid operated rotary power device 10 operative to drive the belt of the conveyor selectively either at a first relatively slower rate or a second relatively faster rate. The upper end of conveyor 6 is located above the receiving end of conveyor 11. Conveyor 11 is of the endless belt type driven in conventional fashion to carry tobacco received from conveyor 6 to the packer (not shown).In typical installations, the packer has its own conveyor, called a charger feed conveyor, for feeding the tobacco it receives into the charger of the packer preparatory to a packing stroke of the packer ram. The packers are usually quite tall and located some distance away from the redryer, so conveyor 11 can be quite long.

Fig. 2 illustrates how operation of the apparatus of Fig. 1 is commenced. One start-up, conveyor 1 is operated continuously at its constant rate while conveyor 2 is operated at a slow rate in a direction to feed the tobacco it receives from conveyor 1 onto the receiving end of the belt of conveyor 6 which, at this stage, is operated at its first, slower rate.

Operation of conveyors 1, 2 and 6 continues in this fashion until load cells 9 detect the desired predetermined rate of tobacco, i e., that weight required for one cycle of operation of the packer. When that occurs, two changes are made simultaneously. Thus, as indicated in Fig. 2A, conveyor 2 is reversed and conveyor 6 is shifted to its higher rate. Thus the additional tobacco being delivered by conveyor 1 is now carried to the right, as viewed, by conveyor 2 which now serves as a holding conveyor. since reversal of conveyor 2 stopped the transfer of tobacco from conveyor 2 to conveyor 6, conveyor 6 now carries the weighed predetermined quantity of tobacco, indicated at A, which will satisfy one cycle of operation of the packer, and conveyor 6 is now moving at its higher rate.Accordingly, as seen in Fig. 2B, conveyor 6 delivers quantity A onto conveyor 11 while the amount of tobacco being held on conveyor 2, while constantly increasing because of the continued delivery of tobacco by conveyor 1, is still small enough to be accommodated. Delivery of quantity A onto conveyor 11 frees conveyor 6 of the tobacco weight. When this occurs, as detected by the load cells, two changes in operation are made. Conveyor 2, is again reversed, so as to deliver its held tobacco, as well as tobacco incoming from conveyor 1, to conveyor 6. And conveyor 6 is shifted back to its slow speed so as to act again to collect the predetermined weight of tobacco necessary for one cycle of operation of the charger. This stage in the sequence of operations is shown in Fig. 2C.

From Fig. 2C, it will be noted that operation of the conveyors in the manner just described is effective to divide the constant feed of tobacco from conveyor 1 into individual increments, each of predetermined weight, and to locate those increments, such as quantity A, on conveyor 11 in such fashion that each successive pair of increments is separated, lengthwise of conveyor 11, by the same interval I, Fig. 6, this interval being of long enough duration, in the light of the speed of conveyor 11, to allow one complete cycle of operation of the packer. Accordingly, the packer is operated so as to achieve one complete cycle of operation within each interval

Claims

1. The method for supplying tobacco from a redryer to a packer and operating the packer, comprising (A) operating a first conveyor to carry tobacco from the redryer and deposit the tobacco continuously at a substantially constant rate onto a reversible endless second conveyor; (B) operating the second conveyor in one direction to feed tobacco received from the first conveyor onto the input end of an endless variable speed third conveyor constructed and arranged to weigh the tobacco as the tobacco is deposited thereon;; (C) operating the third conveyor at a first relatively slow rate until a predetermined weight of tobacco has been deposited thereon by the second conveyor and, upon occurrence of said predetermined weight operating the third conveyor at a second relatively fast rate, and reversing the second conveyor so that the second conveyor ceases to supply tobacco to the third conveyor and operates as a holding conveyor; (D) continuing to operate the third conveyor at said second speed until the entire weighed quantity of tobacco has been discharged from the third conveyor onto a fourth conveyor to supply tobacco from the third conveyor to the packer; (E) upon completion of discharge of the weighed quantity of tobacco from the third conveyor onto the fourth conveyor again reversing the second conveyor to feed its held tobacco as well as incoming tobacco from the first conveyor onto the now empty third conveyor, and returning the third conveyor to said first relatively slow rate; then repeating the steps (C)-(E) for as many cycles as required for the time period of operation of the redryer and packer, the weighed quantities of tobacco received by the fourth conveyor from the third conveyor being separated on the fourth conveyor by intervals determined by the rates of operation of the conveyors; and operating the packer through one complete packing cycle during each such interval.

2. The method of supplying tobacco from a redryer to a packer and operating the packer substantially as hereinbefore described.

3. Apparatus for supplying tobacco from a redryer to a packer substantially as described with reference to and as illustrated in the accompanying drawings.