WO2016067181A1

WO2016067181A1 - Tobacco recovery device and machine for making smokers' articles.

Info

Publication number: WO2016067181A1
Application number: PCT/IB2015/058239
Authority: WO
Inventors: Mauro Galli; Michele Moro; Davide ZEDDA; Gianni CHINARELLI; Massimo Sartoni
Original assignee: G.D S.P.A.
Priority date: 2014-10-27
Filing date: 2015-10-26
Publication date: 2016-05-06

Abstract

A tobacco recovery device in a machine for making smokers' articles comprises feed means (2) for feeding a quantity of loose tobacco, a sieve (3) positioned immediately downstream of the feed means (2), forming a tobacco flowing surface (A) and provided with a plurality of through slots (4) for allowing the passage of a usable portion (U) of the tobacco from a first face (3a) of the sieve (3), forming the flowing surface (A), to a second face (3b) of the sieve (3) which is opposite the first face (3a), a vibrating unit (12) associated with the sieve (3) and designed to impart to the sieve (3) a vibrating movement designed to allow both the passage of the usable portion (U) of the tobacco through the slots (4) and the feeding of the tobacco along the flowing surface (A), a discharge duct (13) operatively positioned downstream of the sieve (3), connectable to a recovery unit (103) of the machine for making smokers' articles, and tobacco removing means (15) operating on the second face (3b) of the sieve (3) for removing tobacco blockages from the slots (4).

Description

DESCRIPTION

TOBACCO RECOVERY DEVICE AND MACHINE FOR MAKING

SMOKERS' ARTICLES.

Technical field

This invention relates to a tobacco recovery device and to a machine for making smokers' articles, preferably cigarettes.

This invention is thus applicable in particular in the tobacco industry and, more specifically, in the construction of production lines which process tobacco known as "reconstituted tobacco".

Background art

In the tobacco industry, the term "reconstituted tobacco" is used to denote the result of a process of converting and/or recovering tobacco which was previously unusable (for example, on account of its reduced size and/or the presence of pieces of stem) into a product which is usable like ordinary tobacco.

It should be noted that the tobacco thus recovered, although similar to and machinable in much the same way as ordinary tobacco, has some distinctions from ordinary tobacco, leading to critical conditions in the processing of both types of tobacco in machines designed to operate in the traditional way.

In particular, at the duct where the tobacco is fed and selected, it is not infrequent for the reconstituted tobacco to be rejected erroneously, and in non-negligible quantities, together with the stems.

Considering also the higher cost of reconstituted tobacco compared to ordinary tobacco, this considerably reduces the cigarette production efficiency of traditional cigarette makers and has led to the creation of specific modules capable of separating reconstituted tobacco from the stems (that is, from the waste proper) and to return only usable tobacco into the production cycle.

Reconstituted tobacco modules typically comprise a vibrating sieve having openings of two different sizes so that the waste particles (that is, the stems) of larger size can only pass through the larger openings, allowing the reconstituted tobacco to pass into a recovery duct through slots of smaller size.

Disadvantageously, this solution is not free of disadvantages. In effect, the reduced size of the slots for the passage of the reconstituted tobacco, together with the oblong, string-like shape of the reconstituted tobacco leads to frequent blocking of the sieve, requiring numerous cleaning operations by an operator (who may or may not need to stop the machine, depending on circumstances).

This is clearly a problem in terms both of productivity and reliability, depending solely on the promptness of the operator's action.

Moreover, frequent blocking of the slots means that the reconstituted tobacco is left free to flow past the slots and to reach the larger openings and, from there, is discarded with the waste.

Disclosure of the invention

This invention therefore has for an aim to provide a tobacco recovery device and a machine for making smokers' articles, preferably cigarettes, which overcome the disadvantages described above with reference to the prior art.

In particular, the aim of this invention is to provide a tobacco recovering device and a machine for making smokers' articles, preferably cigarettes which are high performing and reliable.

More precisely, the aim of this invention is to provide a device for recovering tobacco, in particular reconstituted tobacco, and which does not require operator intervention.

These aims are achieved by a device for recovering tobacco, preferably from cigarettes, having the features of one or more of the appended claims 1 to 1 1 , and by a machine for making smokers' articles comprising the features of claims 12 or 13.

More specifically, the device according to the invention comprises feed means for feeding a quantity of loose tobacco, a sieve positioned immediately downstream of the feed means, forming a tobacco flowing surface and provided with a plurality of through slots for allowing the passage of a usable portion of the tobacco from a first face of the sieve, forming the flowing surface, to a second face of the sieve which is opposite the first face, a vibrating unit associated with the sieve and designed to impart to the sieve a vibrating movement designed to allow both the passage of the usable portion of the tobacco through the slots and the feeding of the tobacco along the flowing surface, and a discharge duct operatively positioned downstream of the sieve, connectable to a recovery unit of the machine for making smokers' articles.

According to the invention, the device comprises tobacco removing means operating on the second face of the sieve for removing tobacco blockages from the slots.

Preferably, these means are periodically active at predetermined time intervals.

Still more preferably, the removing means are configured to be activated without interrupting the operation of the device, that is to say, without hampering or obstructing the flow of tobacco.

Advantageously, the recovering device is thus able to recover the usable portion of the tobacco (for example, reconstituted tobacco) in a substantially continuous manner without bringing the machine to a stop or requiring operator intervention.

Preferably, the removing means are mechanical and/or pneumatic.

According to one aspect of the invention, the removing means comprise at least one scraping unit operating on the second face of the sieve. Alternatively, or in addition to, the removing means comprise at least one blowing unit designed to generate an air flow towards the second face of the sieve so as to remove tobacco residues which block the slots. Brief description of the drawings

Further features and advantages of the invention are more apparent from the following exemplary and therefore non-limiting description of a preferred and hence non-exclusive embodiment of a tobacco recovering device and a machine for making smokers' articles, as illustrated in the accompanying drawings, in which:

- Figure 1 shows a perspective view of a machine for making smokers' articles according to this invention;

- Figure 1 a shows a perspective view of a detail from Figure 1 defining a tobacco recovering device according to the invention;

- Figure 2 shows a side view of a tobacco recovering device according to the invention;

- Figures 3 and 4 are side views of a detail of the device of Figure 2 in two different operating positions;

- Figure 5 shows a front cross section of the detail of Figures 3 and 4 in a further operating condition.

Detailed description of preferred embodiments of the invention

With reference to the accompanying drawings, the numeral 1 denotes a tobacco recovering device associated preferably with a machine 100 for making smokers' articles (preferably, but not necessarily, cigarettes).

More specifically, the machine 100 comprises a hopper 101 for feeding and selecting the tobacco 1 and configured to selectively divide the "usable" tobacco from the waste or stems "C".

Preferably, the hopper 101 operates pneumatically and carries the tobacco by air. Associated with the hopper 101 there is a tobacco rejection unit 102 designed to receive the waste or stems "C" released by the hopper 101 . Preferably, the unit 102 is located in a lower portion of the duct in such a way as to recover the material that settles onto it by gravity.

It is not rare for "usable" tobacco to be mixed with the waste because, on account of its size or for other reasons, it is not carried upwards in the hopper 101 and instead falls in non-negligible amounts into the unit 102 and mixes with the stems "C".

This happens often when the machine 100 works with "reconstituted tobacco" (tobacco which was previously unusable and has been converted into a usable product similar to ordinary tobacco) which, on account of its string-like form and low lift force, tends to fall into the unit 102.

in use, therefore, the unit 102 contains a tobacco waste or stem portion "C" and a usable portion "U", typically but not exclusively consisting of reconstituted tobacco.

The recovering device 1 is therefore preferably connected to the unit 102 to receive the rejected tobacco (waste portion "C" and usable portion "U") and extracts from it only the usable portion "U" to return it into the production cycle.

More precisely, the device 1 comprises feed means 2 for feeding a quantity of loose tobacco. The feed means are associated with the unit 102 to receive the tobacco rejected by the hopper 101 .

Preferably, the feed means 2 are defined by an air conveyor pipe in which the tobacco is moved by means of an aeration or ventilation system.

Preferably, at an end stretch 2a of the feed means 2 there is an accumulation unit 2b configured to eliminate the tobacco conveyor turbulence.

Downstream (preferably immediately downstream) of the feed means 2, the device 1 comprises a sieve 3 forming a tobacco flowing surface "A". The sieve 3 has a first face 3a, defining the flowing surface "A", and a second face 3b opposite to the first face 3a.

The sieve 3 also has a plurality of through slots 4 for allowing the passage only of the usable portion "U" of the tobacco from the first face 3a to the second face 3b.

The sieve 3 is thus defined by a substantially flat, perforated plate 5.

More precisely, the sieve 3 has a plurality of through openings 6 located at a position distal from the feed means 2 relative to the slots 4.

The sieve 3 extends along a tobacco flowing direction "B" between a first end, proximal to the feed means 2, and a second end, distal from the feed means 2.

Thus, the slots 4 are proximal to the first end, whilst the openings 6 are proximal to the second end.

It should be noted that the openings 6 are larger in size than the slots 4 so that the waste or stem portion "C" of the tobacco can pass through them.

In other words, the slots 4 define a fine-mesh grid 7 whilst the openings 6 define a large-mesh grid 8.

Thus, the waste portion "C" of the tobacco, which is made up of large particles, does not pass through the slots 4 and instead flows towards the openings 6.

The usable portion "U" of the tobacco, on the other hand, which is made up of smaller particles, falls through the slots 4 immediately and can thus be recovered.

In the preferred embodiment, therefore, the sieve 3 comprises a plate 5 extending between its first end, which the grid 7 is associated with, and its second end, which the grid 8 is associated with.

Preferably, the grid 7 comprises at least a middle partition 9 located at the first face and extending along the flowing direction "B" to divide the grid 7 into a first half-part 7a and a second half-part 7b. It should be noted that the middle partition 9 is laterally delimited by two longitudinal edges 9a extending along the tobacco feed direction "B", each adjacent to a respective half-part 7a, 7b of the grid 7.

Preferably, the longitudinal edges 9a each have at least one guide portion 9b extending, the same way as the feed direction "B", between an end distal from the respective half-part 7a, 7b and an end proximal to the respective half-part 7a, 7b of the grid 7.

In the embodiment illustrated, the longitudinal edges 9a have a sawtooth shape, where each tooth 10 defines a guide portion 9b.

Further, the grid 7 also preferably has two lateral borders 1 1 , also provided with respective guide portions 1 1 a (similar to those of the middle partition 9) and located at the lateral ends of the grid 7 to guide the tobacco onto the slots 4.

In order to facilitate the passage of the usable portion "U" through the slots 4, the device 1 comprises a vibrating unit 12 associated with the sieve 3 and configured to impart a vibrating movement designed to cause the tobacco to bounce and move along the flowing surface "A".

More precisely, the vibrating movement makes it easier for the usable portion "U" to pass through the slots 4 and at the same time causes the tobacco, in particular the waste portion "C", to flow away along the feed direction.

The vibrating unit 12 is preferably connected rigidly to the plate 5. Alternatively, the plate 5 might be flexible and elastic in such a way as to have a vibrating movement.

The device 1 further comprises at least one discharge duct 13 operatively located downstream of the sieve 3, in particular under the slots 4, to allow recovering the usable portion "U" of the tobacco.

The recovery duct 13 is preferably connected (or connectable) to a recovery unit 103 of the machine 100 for making smokers' articles.

Preferably, the recovery duct 13 comprises a collecting tank 13a facing the second face 3a of the sieve 3, at the slots 4, and at least one tube designed to carry (by air) the usable portion "U" (for example, reconstituted tobacco) into the production stations of the machine 100. The device 1 is also provided with a rejection duct 14, also operatively located downstream of the sieve 3, in particular under the openings 6, to allow the waste or stem portion "C" to flow out.

The rejection duct 14 is preferably associated with a rejection circuit 104 of the machine 100, designed to convey the waste portion "C" into specific collectors or into a centralized collection circuit.

According to a core aspect of the invention, the device comprises tobacco removing means 15 operating on the second face 3b of the sieve 3 for removing tobacco from the slots 4.

Advantageously, the recovering device is able to recover the usable portion of the tobacco (for example, reconstituted tobacco) in a substantially continuous manner without bringing the machine to a stop or requiring operator intervention.

In this regard, the removing means 15 are preferably active periodically at predetermined time intervals.

Still more preferably, the removing means 15 are configured to be activated without interrupting the operation of the device 1 , that is to say, without hampering or obstructing the flow of tobacco (that is, without affecting the first face 3a of the sieve 3).

The removing means 15 are preferably at least partly mechanical, acting directly on the second face 3b of the sieve 3, at the slots 4 (and thus at the grid).

For this purpose, the removing means 15 preferably comprise at least one scraping unit 17 operating on the second face 3b of the sieve 3.

Thus, the scraping unit 17 is configured to slide on the second face 3b of the sieve 3, at the slots 4, in order to cut or sweep away the string-like tobacco residues hanging from the bottom of the slots 4 themselves. More precisely, the scraping unit 17 comprises at least one blade 18 slidably associated with the second face 3b of the sieve 3, that is, of the grid 7, for moving between a first and a second position with reciprocating motion.

The blade 18 is preferably defined by a substantially flat element 20 having an end edge abutted against the second face 3b of the sieve 3 to slide thereon.

The substantially flat element 20 thus extends in a plane transversal to the sieve 3.

The blade 18 is associated with an actuator 19 configured to move it from the first to the second position, and vice versa, at predetermined regular intervals, or in response to a command issued by an operator.

In the embodiment illustrated, the actuator 19 is a linear piston 19a.

Thus, the blade 18 is moved along a (straight) line of movement "D".

Alternatively, other types of actuators are imaginable without departing from the spirit of the invention.

It should be noted that the scraper 17 (and thus the actuator 19 and the blade 18) is rigidly connected to the sieve 3 in such a way as to oscillate as one therewith.

At its first position, the blade 18 is preferably located outside an area occupied by the slots 4, under the second face 3b.

Advantageously, therefore, when the blade 18 is "at rest", it does not interfere with the tobacco "U" flowing out through the slots 4, that is, through the grid 7.

Preferably, when it is at the first position, the blade 18 is located at (that is, under) the middle partition 9 or a lateral border 1 1 .

To reduce the length of its stroke and increase its speed, the scraping unit 17 preferably comprises a first blade 18a and a second blade 18b which are aligned with each other and spaced along the line of movement "D". Each blade 18a, 18b operates on a specific half-part 7a, 7b of the grid 7 (that is, of the sieve 3).

Preferably, the blades 18a, 18b are rigidly connected to each other and move in the same way along the line of movement "D".

Alternatively, the actuator might comprise a transmission unit configured to move the first and second blades reciprocatingly towards and away from each other.

It should be noted that at the first position, the blade 18a is located at (that is, under) a lateral border 1 1 , whilst the second blade 18b is located at (that is, under) the middle partition 9.

Alternatively or in addition to the scraper 17, the removing means 15 comprise at least one pneumatic unit 16, which also operates on the slots 4 to clear tobacco blockages.

Preferably, the pneumatic unit 16 comprises at least one blowing unit 20 configured to generate an air flow towards the second face 3b of the sieve 3 so as to remove tobacco residues which block the slots 4.

Preferably, the blowing unit 20 is located under the second face 3b of the sieve 3 and is configured to generate an air flow directed towards the second face 3b itself, in particular towards the grid 7.

In the embodiment illustrated, the blowing unit 20 comprises a plurality of blowing nozzles 21 facing and directed towards the grid 7 (that is, towards the second face 3b of the sieve 3).

Preferably, the blowing nozzles 21 are located between the grid 7 and the collecting tank 13a.

More precisely, there is a collecting chamber having at least a front wall 22a and a rear wall 22b, preferably defining a hopper.

The blowing nozzles 21 are anchored to the front wall 22a and to the rear wall 22b, with opposite orientation but all directed towards the grid.

It should be noted that in the preferred embodiment, the pneumatic unit 16 and the scraping unit 17 are both present and act in conjunction in order to better clean the sieve 3. In effect, the scraping unit 17 cuts or sweeps away the tobacco residues (in particular, the usable tobacco "U") hanging from the bottom of the grid 7, whilst the pneumatic unit 16 blows from the bottom up to remove the residues, including those cut, which are lodged in the slots and cannot be dislodged by the movement of the scraping unit 17.

The invention achieves the above mentioned aims and brings important advantages.

In effect, the presence of sieve cleaning means which are fully automatic and which do not interfere with tobacco flow allows maximizing the efficiency of the device.

Further, the use of a scraping unit which, when at rest, only minimally interferes with the passage of the tobacco allows keeping productivity high.

Also, a pneumatic unit which uses a resource (i.e. air) used for several other purposes in the machine allows maximizing the capability of cleaning the sieve.

Moreover, the combined use of scraper and pneumatic unit allows obtaining the best cleaning effect very quickly and limits the need for "aggressive" action by the scraper.

Claims

1 . A machine for making smokers' articles, characterized in that it comprises:

- a hopper (101 ) for feeding and selecting the tobacco;

- a tobacco rejection unit (102) associated with the hopper (101 );

- a tobacco recovery device (1 ), comprising:

- feed means (2) for feeding a quantity of loose tobacco;

- a sieve (3) positioned immediately downstream of said feed means (2), forming a tobacco flowing surface (A) and provided with a plurality of through slots (4) for allowing the passage of a usable portion (U) of said tobacco from a first face (3a) of the sieve (3), forming the flowing surface (A), to a second face (3b) of the sieve (3) which is opposite the first face (3a);

- a vibrating unit (12) associated with said sieve (3) and designed to impart to the sieve (3) a vibrating movement designed to allow both the passage of the usable portion (U) of said tobacco through the slots (4) and the feeding of the tobacco along the flowing surface (A);

- a discharge duct (13) operatively positioned downstream of said sieve (3), connectable to a recovery unit (103) of the machine for making smokers' articles;

- tobacco removing means (15) for removing tobacco blockages from said slots (4), said removing means (15) comprising at least one scraping unit (17) operating on said second face (3b) of the sieve (3);

- a recovery unit (103) for recovering said usable portion (U) of the tobacco associated with said discharge duct (13) and configured to feed said usable portion (U) of the tobacco back into said feed duct or downstream of it.

2. The machine according to claim 1 , characterized in that the removing means (15) are periodically active at predetermined time intervals.

3. The machine according to claim 1 or 2, characterized in that said scraping unit (17) comprises at least one blade (18) slidably associated with said second face (3b) for moving between a first and a second position with reciprocating motion.

4. The machine according to claim 3, characterized in that, at said first position, the blade (18) is located outside an area occupied by said slots (4) under the second face (3b).

5. The machine according to claim 3 or 4, characterized in that said scraping unit (17) comprises a first blade (18a) and a second blade (18b) which are aligned with one another and spaced along a predetermined line (D) of movement, each operating on a predetermined half-part (7a, 7b) of the sieve (3).

6. The machine according to claim 5, characterized in that said sieve (3) comprises at least a middle partition (9) located at the first face (3a) designed to divide the sieve (3) into a first half-part (7a) and a second half-part (7b); said second blade (18b), in said first position, being located at said middle partition (9) in order to allow the outflow of the tobacco.

7. The machine according to claim 6, characterized in that said middle partition (9) is laterally delimited by two longitudinal edges (9a) extending along a direction of feed (B) of the tobacco, each adjacent to a respective half-part (7a, 7b) of the sieve (3); said longitudinal edges (9a) each having at least one guide portion (9b) extending, the same way as said direction of feed (B), between an end distal from the respective half-part (7a, 7b) and an end proximal to the respective half-part (7a, 7b) of the sieve (3).

8. The machine according to any one of the preceding claims, characterized in that said removing means (15) comprise at least one blowing unit (20) designed to generate an air flow towards said second face (3b) of the sieve (3) so as to remove tobacco residues which block the slots (4).

9. The machine according to claim 8, characterized in that said blowing unit (20) comprises a plurality of blowing nozzles (21 ) facing said second face (3b) of the sieve (3).

10. The machine according to claim 1 or 2, characterized in that said sieve (3) comprises a plurality of openings (6) which are distal from the feed means (2) relative to said slots (4) and are larger than the slots (4), for allowing through a waste portion (C) of the tobacco.

1 1 . The machine according to any one of the preceding claims, characterized in that said sieve (3) of the device comprises a plurality of openings (6) which are distal from the feed means (2) relative to said slots (4) and are larger than the slots (4) for allowing through a waste portion (C) of the tobacco; said machine also comprising a rejection circuit (104) associated with said openings (6).