GB1579363A - Method and apparatus for controlling a tobacco cutter - Google Patents

Description

(54) METHOD AND APPARATUS FOR CONTROLLING A TOBACO CUTTER (71) We, HAUNI-WERKE KÖRBER & BR< Co. K.G., a German company of Kampchaussee 12-22, 2050 Hamburg 80, Germany (Fed. Rep.) do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to a method for controlling a tobacco cutter, to which tobacco is supplied continuously for the purpose of forming a store, from which the tobacco is continuously removed, compacted and cut.

The invention also relates to an apparatus for cutting tobacco, with means for supplying tobacco continuously to a storage chute.

Such a method and apparatus are described and claimed in our Patent Application No. 3454/76 (Serial No. 1538099) and the present invention is a modification thereof.

According to a first aspect of the present invention, there is provided a method of controlling a tobacco cutter to which tobacco is continuously supplied, otherwise than in a constant flow per unit time, in order to form a store, from which tobacco is continuously removed, compacted and cut by the cutter, wherein the amount of the tobacco in the store is monitored and the cutting speed of the tobacco cutter is controlled in dependence upon said amount in order to keep said amount at least approximately constant.

According to a second aspect of the present invention, there is provided apparatus for cutting tobacco, comprising a tobacco cutter having a storage chute for holding a store of tobacco awaiting removal, compaction and cutting by the cutter, means for supplying tobacco continuously otherwise than at a constant flow per unit time to the storage chute, monitoring means for monitoring the amount of tobacco stored in the storage chute, and tobacco cutter speed control means responsive to said monitoring means in order to keep said amount at least approximately constant.

The invention will now be further described by way of example only, with reference to the accompanying drawing, in which: Fig. 1 is a diagrammatic sectional view of a tobacco cutter, Fig. 2 is a block circuit diagram of the speed control device according to the invention.

Fig. 3 is a plan view of a group of tobacco cutters shown diagrammatically and Fig. 4 shows a feed device for a group of tobacco cutters in a view on line IV-IV according to Fig. 3.

The tobacco cutter illustrated in Fig. 1 comprises a substantially vertical storage chute 1, which contains tobacco 2 in the form of leaf material forming a store. Located in the lower part of the storage chute 1, in the region of its rear wall, is a rake 3 able to move to and fro in a cycle in the direction of the arrow, which rake 3 supplies the tobacco 2 in a steady succession to a pressing device 7 consisting of two pressing chains 4 and 6. The pressing chains 4 and 6 which converge in the feed direction (arrow 8) and are driven by a drive in the form of an electric motor (d.c.

motor) 9, engage the leaf material and convey it to a mouthpiece 14 consisting of an upper part 12 and lower part 13, whilst pressing it and compacting it to form a cake 11. A pressure generator 16 acts on the pressing chain 4. The lower part 13 forms the counter cutter for cutters 17 in a cutter drum 18 likewise rotated by the drive 9, so that as they rotate, the cutters 17 cut narrow strips of tobacco fibres 19 from the tobacco cake 11.

The tobacco fibres 19 are then discharged in the direction of arrow 21.

A grinding wheel 22 which is dressed by a diamond 23 serves for grinding the cutters 17.

The tobacco cutter is also preceded by a continuously operating constantly controllable loading device 26 which consists essentially of a conveyor belt 31 provided with pins 27 and guided over rollers 28 and 29, which belt may be driven by an electric motor (d.c. motor) 32 and forms one wall of a container 33 filled with tobacco 2. The loading device 26 is preceded by a conveyor belt 34 for filling the container 33 with tobacco 2, a photoelectric cell 36 inside the container 33 monitoring the filling condition of the container 33 and when necessary actuating an electric motor 37 driving the conveyor belt 34.

Provided inside the storage chute 1 of the tobacco cutter is a monitoring means for the storage level of tobacco 2 in the form of two monitoring devices constructed as photoelectric cells 46 and 47, which are arranged one above the other and co-operate with a speed control device 48, which for the purpose of an increase or decrease acts on the motor 9 to drive the tobacco cutter, which is indicated by a line of action 49 shown in dot-dash line.

The construction of the speed control device is illustrated with reference to Fiv. 2.

The speed control device 48 comprises three AND-gates 51, 52 and 53, whereof the AND-gate 51 is connected at its inputs a and b by way of an inverter gate 54, 56 to the two photo-electric cells 46 and 47, the AND-gate 52 is connected at its input a directly to the photo-electric cell 46 and by its input b once more by way of an inverter gate 57, to the photo-electric cell 47 and the AND-gate 53 is connected by its inputs a and b directly to the two photo-electric cells 46 and 47. The outputs c of the AND-gates 51, 52, 53 are connected resDectively to reference value transmitters 5,59, 61 in the form of potentiometers whereof the reference value transmitter 59 is set at an average speed reference value, the reference value transmitter 58 at a higher speed reference value and the reference value transmitter 61 at a lower speed reference value.Also associated with the reference value transmitters 58, 59 and 61 are reference junctions 62 to 64, which may be supplied with an actual speed value by a tachometer 66 of the motor 9. The reference junctions 62 to 64 are connected to a control member 67 for varying the speed of the electric motor 9. The control member 67 is appropriately constructed as a thyristor amplifier with a d.c. output, as sold under the name "Mini-semi" by the firm AEG.

The aforedescribed apparatus operates as follows: The adding device 2)5 driven by the electric motor 32 removes tobacco in the form of leaf material from the container 33 filled by the conveyor belt 34 and conveys it continuously to the storage chute 1 of the tobacco cutter.

In order to ensure that the tobacco introduced into the storage chute can be processed at any time by the tobacco cutter, the photo-electric cells 46 and 47 co-operate with the speed control device 48 in the manner described hereafter with reference to figure 2.

Provided that the storage height of the tobacco 2 or the tobacco level moves between the two photo-electric cells 46 and 47, the tobacco cutter is driven at a normal average speed of the motor 9, which is achieved due to the fact that the photo-electric cell 46 which is not covered sends a signal to the input a of the AND-gate 52 and the photoelectric cell 47 which is covered emits no signal, due to which a signal likewise appears at the input b of the AND-gate 52 as a result of negation by the inverter gate 57. The AND-gate 52 accordingly sends an output signal to the reference value transmitter 59, which sends a corresponding reference value signal to the control member 67 by way of the reference junction 63, so that the electric motor 9 and thus the tobacco cutter are driven at an average speed.Simultaneous actuation of the two other reference value transmitters 38, 61 is prevented due to the fact that the AND-gates 51 and 53 associated therewith do not emit an output signal, since the signal emitted by the photo-eectric cell 46 for the input a of the AND-gate 52 is negated and only its input b receives an input signal due to the negated non-existent signal of the photo-electric cell 47. Similarly, the AND-gate 53 only receives a signal at the input a from the photo-electric cell 46 and its input b does not receive a signal from the photo-electric cell 47.

When the storage level of the tobacco 2 in the storage chute 1 increases, i.e. the tobacco level reaches the photo-electric cell 46, or even exceeds the latter, then both photoelectric cells 46 and 47 are covered and no longer emit any signals. This has the result that the AND-gate 53 emits no output signal, since its two inputs a and b do not receive any signals from the photo-electric cells 46 and 47, whereas the AND-gate 52 likewise no longer sends an output signal to the reference value transmitter 59, since the input a of the AND-gate 52 no longer receives the signal from the photo-electric cell 46. On the other hand, input signals now occur at the inputs a and b of the AND-gates 51 as a result of negation by the inverter gates 54 and 56 of the non-existent signals from the photoelectric cells 46 and 47. The AND-gate 51 therefore sends an output signal to the associated reference value transmitter 58, which by way of the reference junction 62 causes the control member 67 to increase the speed of the electric motor 9. In this manner, the tobacco cutter is in a position to process the larger quantity of tobacco in the storage chute 1, due to its higher speed, so that the tobacco level once more drops.

If the tobacco level falls short of the lower photo-electric cell 47, then both photoelectric cells 46 and 47 emit signals, which are negated before the inputs a and b of the AND-gate 51, so that the output signal of the latter disappears. In addition, the AND-gate 52 receives only one input signal from the photo-electric cell 46, whereas its input b does not receive a signal owing to negation of the signal from the photo-electric cell 47, so that the AND-gate 52 also does not emit an output signal.Now, the AND-gate 53 receives input signals from the photo-electric cells 46 and 47 and thus sends an output signal to the associated reference value transmitter 61, which by way of the reference junction 64 actuates the control member 67 to reduce the speed of the electric motor 9, due to which further lowering of the tobacco level in the storage chute 1 is prevented and the tobacco level may thus once more rise.

In the embodiment according to Figs. 3 and 4, parts which correspond to those of Figs. 1 and 2 are provided with the same reference numerals increased by 100 and are not described again in detail.

According to figure 3, several, in the present case three tobacco cutters 168, 169 and 171, are combined to form a group 172 of tobacco cutters. The group 172 of tobacco cutters is supplied continuously with tobacco, which passes from the container 133 onto a vibrating conveyor trough 173 and from there passes to a distribution hopper 174, which distibutes the tobacco uniformly to the tobacco cutters 168, 169, 171 of the group 172 of tobacco cutters through three chutes 176 to 178 by way of interposed vibrating conveyor troughs 179, 182, 184. The cut tobacco stream leaving the group 172 of tobacco cutters is discharged by a common discharge conveyor 186.

The distribution hopper 174 is also provided with feed barriers in the form of controllable flaps 187 to 189, associated with each of the chutes 176 to 178. The flaps 187 and 189 are in operative connection with a tachometer 198,199,201 by way of a control member 191 to 193 and an amplifier 194, 196, 197, which tachometers are associated with the drive motors 202, to 204 of the tobacco cutters 168 to 171.

If one or more tobacco cutters 168 to 171 of the group 172 of tobacco cutters breaks down, in the embodiment illustrated according to Fig. 4 the tobacco cutter 169, then the tachometer 201 of the associated drive motor 204 sends a corresponding signal to the control member 193, which moves the flap 188 into the closing position shown, so that tobacco can no longer pass through the closed chute 178 to the tobacco cutter 169 which is out of operation. The tobacco supplied is now distributed uniformly to the two tobacco cutters 168 and 171, which leads to an increase in the tobacco level in these tobacco cutters. This has the result that the individual speed control devices according to Fig. 2 associated with all the tobacco cutters react correspondingly and cause the tobacco cutters 168 and 171 which have not broken down, to increase their cutting capacity or increase their speed.

It is within the framework of the invention to provide one photo-electric cell in the storage chute in place of two, or to locate more than two photo-electric cells one above the other.

The advantage achieved by the invention consists in that tobacco offered to the individual tobacco cutters or group of tobacco cutters can be received and processed at any time even if the tobacco level in the storage chute is subject to considerable fluctuations, in particular rises so far that without the speed control according to the invention, the excess tobacco would have to be returned.

In this way, the flow per unit time supplied by the tobacco cutter or group of tobacco cutters is kept largely constant or free from long term fluctuations.

WHAT WE CLAIM IS: 1. A method of controlling a tobacco cutter to which tobacco is continuously supplied, otherwise than in a constant flow per unit time, in order to form a store, from which tobacco is continuously removed, compacted and cut by the cutter, wherein the amount of the tobacco in the store is monitored and the cutting speed of the tobacco cutter is controlled in dependence upon said amount in order to keep said amount at least approximately constant.

A A method according to claim 1 wherein the level of the store is monitored and the cutting speed of the tobacco cutter is controlled in dependence upon the storage level so as to maintain the storage level at least approximately constant.

3. A method according to claim 2, wherein a predetermined upper storage level and a predetermined lower storage level of the store are monitored, the cutting speed of the tobacco cutter is adjusted to a higher value when the upper storage level is exceeded, to an average value when the upper storage level is not reached and the lower storage level is exceeded, and to a lower value when the lower storage level is not reached.

4. A method according to claim 1, wherein each of a group of tobacco cutters with respective stores is supplied with a continuous flow of tobacco derived from a single feed path, and when one or more tobacco cutters of the group breaks down, the supply to the tobacco cutter or cutters which are out of operation is prevented and the tobacco

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (11)

**WARNING** start of CLMS field may overlap end of DESC **. chute 1, due to its higher speed, so that the tobacco level once more drops. If the tobacco level falls short of the lower photo-electric cell 47, then both photoelectric cells 46 and 47 emit signals, which are negated before the inputs a and b of the AND-gate 51, so that the output signal of the latter disappears. In addition, the AND-gate 52 receives only one input signal from the photo-electric cell 46, whereas its input b does not receive a signal owing to negation of the signal from the photo-electric cell 47, so that the AND-gate 52 also does not emit an output signal.Now, the AND-gate 53 receives input signals from the photo-electric cells 46 and 47 and thus sends an output signal to the associated reference value transmitter 61, which by way of the reference junction 64 actuates the control member 67 to reduce the speed of the electric motor 9, due to which further lowering of the tobacco level in the storage chute 1 is prevented and the tobacco level may thus once more rise. In the embodiment according to Figs. 3 and 4, parts which correspond to those of Figs. 1 and 2 are provided with the same reference numerals increased by 100 and are not described again in detail. According to figure 3, several, in the present case three tobacco cutters 168, 169 and 171, are combined to form a group 172 of tobacco cutters. The group 172 of tobacco cutters is supplied continuously with tobacco, which passes from the container 133 onto a vibrating conveyor trough 173 and from there passes to a distribution hopper 174, which distibutes the tobacco uniformly to the tobacco cutters 168, 169, 171 of the group 172 of tobacco cutters through three chutes 176 to 178 by way of interposed vibrating conveyor troughs 179, 182, 184. The cut tobacco stream leaving the group 172 of tobacco cutters is discharged by a common discharge conveyor 186. The distribution hopper 174 is also provided with feed barriers in the form of controllable flaps 187 to 189, associated with each of the chutes 176 to 178. The flaps 187 and 189 are in operative connection with a tachometer 198,199,201 by way of a control member 191 to 193 and an amplifier 194, 196, 197, which tachometers are associated with the drive motors 202, to 204 of the tobacco cutters 168 to 171. If one or more tobacco cutters 168 to 171 of the group 172 of tobacco cutters breaks down, in the embodiment illustrated according to Fig. 4 the tobacco cutter 169, then the tachometer 201 of the associated drive motor 204 sends a corresponding signal to the control member 193, which moves the flap 188 into the closing position shown, so that tobacco can no longer pass through the closed chute 178 to the tobacco cutter 169 which is out of operation. The tobacco supplied is now distributed uniformly to the two tobacco cutters 168 and 171, which leads to an increase in the tobacco level in these tobacco cutters. This has the result that the individual speed control devices according to Fig. 2 associated with all the tobacco cutters react correspondingly and cause the tobacco cutters 168 and 171 which have not broken down, to increase their cutting capacity or increase their speed. It is within the framework of the invention to provide one photo-electric cell in the storage chute in place of two, or to locate more than two photo-electric cells one above the other. The advantage achieved by the invention consists in that tobacco offered to the individual tobacco cutters or group of tobacco cutters can be received and processed at any time even if the tobacco level in the storage chute is subject to considerable fluctuations, in particular rises so far that without the speed control according to the invention, the excess tobacco would have to be returned. In this way, the flow per unit time supplied by the tobacco cutter or group of tobacco cutters is kept largely constant or free from long term fluctuations. WHAT WE CLAIM IS:

1. A method of controlling a tobacco cutter to which tobacco is continuously supplied, otherwise than in a constant flow per unit time, in order to form a store, from which tobacco is continuously removed, compacted and cut by the cutter, wherein the amount of the tobacco in the store is monitored and the cutting speed of the tobacco cutter is controlled in dependence upon said amount in order to keep said amount at least approximately constant.

A A method according to claim 1 wherein the level of the store is monitored and the cutting speed of the tobacco cutter is controlled in dependence upon the storage level so as to maintain the storage level at least approximately constant.

3. A method according to claim 2, wherein a predetermined upper storage level and a predetermined lower storage level of the store are monitored, the cutting speed of the tobacco cutter is adjusted to a higher value when the upper storage level is exceeded, to an average value when the upper storage level is not reached and the lower storage level is exceeded, and to a lower value when the lower storage level is not reached.

4. A method according to claim 1, wherein each of a group of tobacco cutters with respective stores is supplied with a continuous flow of tobacco derived from a single feed path, and when one or more tobacco cutters of the group breaks down, the supply to the tobacco cutter or cutters which are out of operation is prevented and the tobacco

flow is distributed to the remaining tobacco cutters, whose cutting speed is increased to keep their individual storage amounts at least approximately constant.

5. Apparatus for cutting tobacco, comprising a tobacco cutter having a storage chute for holding a store of tobacco awaiting removal, compaction and cutting by the cutter means for supplying tobacco continuously otherwise than at a constant flow per unit time to the storage chute, monitoring means for monitoring the amount of tobacco stored in the storage chute, and tobacco cutter speed control means responsive to said monitoring means in order to keep said amount at least approximately constant.

6. Apparatus according to claim 5, wherein the monitoring means is adapted to monitor the level of tobacco stored in the storage chute.

7. Apparatus according to claim 6, wherein the monitoring means consists of a monitoring device marking an upper storage level and a monitoring device marking a lower storage level, associated with which devices is a three-stage speed control member of the speed control means.

8. Apparatus according to claim 7, wherein the monitoring devices consist of photo-electric cells, which are constructed to emit a signal when the respective storage level is not reached.

9. Apparatus according to claim 5, wherein a plurality of said tobacco cutters monitored and controlled individually as regards their storage amounts and cutting speed are combined to form a group of tobacco cutters, associated with which is a common supply conveyor and each tobacco cutter of the group of tobacco cutters is provided with a feed barrier adapted to be moved into an operative position when the respective tobacco cutter breaks down.

10. A method of controlling a tobacco cutter substantially as herein described with reference to the accompanying drawings.

11. Apparatus for cutting tobacco, substantially as herein described with reference to and as illustrated in the accompanying drawings.