Abstract:
The invention concerns an apparatus for the contactless cleaning of a conveying element which is designed to receive rod-shaped articles in the tobacco-processing industry, including at least one ionising element for removing electrostatic charges on the surfaces of the conveying element to be cleaned, at least one rotating compressed-air nozzle for loosening and removing contaminants located on surfaces of the conveying element, and a suction device for extracting the contaminated outgoing air, characterized in that associated with the apparatus is a housing for forming a cleaning chamber at least partially shielded from the environment, whereby the cleaning chamber has an inlet opening and an outlet opening for the conveying element to be cleaned, such that upper side and lower side of the conveying element are surrounded. Furthermore, the invention concerns an arrangement for transporting and/or storing rod-shaped articles with an apparatus for contactless cleaning with the above-mentioned characteristics.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority of German Patent Application No. 10 2004 057 445.6 filed Nov. 24, 2004, the subject matter of which is incorporated herein by reference. The disclosure of all U.S. and foreign patents and patent applications mentioned below are also incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The invention concerns an apparatus for the contactless cleaning of a conveying element which is designed to receive rod-shaped articles in the tobacco-processing industry, including at least one ionizing element for removing electrostatic charges on the surfaces of the conveying element which are to be cleaned, at least one rotating compressed-air nozzle for loosening and removing contaminants located on surfaces of the conveying element, and a suction device for extracting the contaminated outgoing air. Furthermore, the invention concerns an arrangement for transporting and/or storing rod-shaped articles in the tobacco-processing industry, including an endlessly rotating conveying element which has a full strand provided with articles and an empty strand without articles, a guide element which is arranged below the conveying element for guiding and/or supporting it, and an apparatus for cleaning the conveying element, whereby the apparatus for cleaning is arranged in the region of the empty strand. 
     Apparatuses and assemblies of this kind are used for many purposes in the tobacco-processing industry. In the manufacture of cigarettes or the like, tobacco sticks, filter rods, cigarettes or the like are transported, stored, transferred or otherwise conveyed. This purpose is served by conveying elements which can be designed as chains, belts or otherwise. Typical storage assemblies of the ORBIS and VARIOS type are described in detail in the applicant&#39;s European documents EP 0 581 143 B1 and EP 1 445 218 A1, respectively. 
     The conveying elements are at least partially supported and/or guided by a guide element which is arranged below the conveying element. During transport, storage or the transfer of rod-shaped articles, the conveying element is soiled by abrasion of the conveying element itself, residues of the articles located on the conveying element, dust from the environment and in particular also charcoal granules. Particularly the removal of the charcoal granules upon changing brands, but also maintenance of the mobility of the conveying element, necessitates cleaning of the conveying element. It is therefore known that apparatuses for cleaning the conveying elements can be provided. Contactless cleaning apparatuses, for example, electrostatic cleaning apparatuses, with the characteristics mentioned hereinbefore have proved to be particularly effective here. These are arranged in the region of an empty strand of the conveying element. 
     The known apparatuses for cleaning the conveying element have, however, the drawback that they are of open design. This means that in particular rotating compressed-air nozzles and the suction device have a direct effect on the environment. In other words, the compressed-air nozzles blow into the environment the dirt particles loosened from the conveying element. This can firstly lead, for example, to articles which are located on the full strand being blown down off the latter secondly, the articles in the vicinity but also the conveying element itself are again subjected to the contaminated air. The cleaning operation is, to put it another way, uncontrolled, as e.g. dirt particles can also drop onto elements located below the empty strand, e.g. the full strand or other components of these or other apparatuses. 
     SUMMARY OF THE INVENTION 
     It is therefore the object of the present invention to provide an apparatus for cleaning a conveying element which allows reliable and safe cleaning. Furthermore, it is the object of the invention to propose an arrangement for transporting and/or storing rod-shaped articles which ensures safe and reliable cleaning of the conveying element. 
     This object is achieved by an apparatus with the characteristics mentioned hereinbefore by the fact that associated with the apparatus is a housing for forming a cleaning chamber at least partially shielded from the environment, wherein the cleaning chamber has an inlet opening and an outlet opening for the conveying element to be cleaned, such that upper side and lower side of the conveying element are surrounded. With this apparatus, the actual cleaning operation is carried out shielded from the environment. Encapsulation of the cleaning apparatus by the housing allows, in a simple and effective manner, protection of the environment from the outgoing air which is swirled up and contaminated by the compressed-air nozzles and the suction device. Furthermore, the housing ensures that dirt particles loosened by the cleaning operation and falling down are caught and subjected to forced guidance and above all carried away in a controlled fashion. 
     In a preferred development of the invention, the ionising element has at least two ionising rods, whereby the ionising rods are oriented with their longitudinal extent parallel to the conveying element in the direction of travel thereof. Due to this design, a cleaning zone of maximum length is achieved in a narrow space. 
     Advantageously, in the region of the inlet opening and the outlet opening of the cleaning chamber are arranged sealing means which, in a particularly preferred development for complete sealing of the cleaning chamber, are adapted to the contour of the conveying element which is movable through the cleaning chamber. The result is a virtually closed system in which the incoming air, which is conducted into the cleaning chamber as compressed air by means of the compressed-air nozzles, and the outgoing air circulate in closed circuits. With this measure, the environment is protected in a particularly effective manner from loosened and swirled-up dirt particles. 
     Preferably, the guide element is at least partially interrupted in the region of the cleaning chamber. As a result, an additional cleaning effect is obtained by the fact that additional turbulence can be generated, such that the conveying element can be subjected to the cleaning compressed air from below as well. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further preferred and advantageous characteristics and developments are apparent from the subsidiary claims and the description. Particularly preferred embodiments of the invention are described in more detail with the aid of the attached drawings. The drawings show: 
         FIG. 1  a perspective view of a schematic drawing of the apparatus for cleaning with a conveyor chain running through the cleaning chamber, 
         FIG. 2  an enlarged representation of the apparatus according to  FIG. 1  with no housing cover, 
         FIG. 3  a front view of the apparatus, 
         FIG. 4  a sectional view along section B-B according to  FIG. 3 , 
         FIG. 5  a side view of the apparatus, 
         FIG. 6  an enlarged representation of the region of entry of the conveyor chain into the cleaning chamber, 
         FIG. 7  the front view according to  FIG. 3  with no front wall, and 
         FIGS. 8   a+b  different positionings of the apparatus according to  FIG. 1  by the example of a storage arrangement. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The apparatus shown, preferably as part of an arrangement which is only indicated for transporting and/or storing rod-shaped articles, serves for the contactless cleaning of conveyor chains. 
     In  FIG. 1  is shown an apparatus  10  for the contactless cleaning of a conveying element  12  designed as a conveyor chain  11 . The apparatus  10  usually forms part of an arrangement which, in the embodiment described, is designed to transport and/or store rod-shaped articles in the tobacco-processing industry, e.g. filter cigarettes. For this purpose the arrangement comprises the endlessly rotating conveyor chain  11  which includes a full strand and an empty strand. The full strand is the section of the conveyor chain  11  provided with articles. The empty strand, given reference number  13  in  FIG. 1 , is the section of the conveyor chain  11  which is free from articles. The conveyor chain  11  is preferably made of plastic. Other usual materials can, however, be used as well. Furthermore, the arrangement includes a guide element  14  which is arranged below the conveyor chain  11  and serves to guide and/or to support the conveyor chain  11 . The guide element  14  is preferably also made of plastic. It can also be formed from metal or composite materials. In the latter case, a guide element  14  made, for example, of metal is provided with a plastic surface. 
     The apparatus  10  includes an ionising element  15  which in the embodiment shown has two ionising rods  16 ,  17 . The ionising rods  16 ,  17  are oriented with their longitudinal extent parallel to the conveyor chain  11  in the direction of travel or transport T thereof. The ionising rods  16 ,  17  are arranged at a distance from the conveyor chain  11  above and slightly laterally offset from the latter. They have so-called ionising tips  31 ,  32  over their whole length in the longitudinal direction. These ionising tips  31 ,  32  are oriented radially and obliquely to the conveyor chain  11 . This means that the tips  31 ,  32  of the ionising rods  16 ,  17  are directed at an angle onto the conveyor chain  11 , such that the whole width of the conveyor chain  11  can be ionised by the mutually opposed ionising rods  16 ,  17 . The distance between the ionising rods  16 ,  17  and the conveyor chain  11  is variable and depends on various other parameters. Without the support of the compressed air from the compressed-air nozzles  18 , the distance is e.g. max. 100 mm. With the support of the compressed air from the compressed-air nozzles  18 , the distance can also be up to 500 mm. Other distances are, however, possible too. 
     Furthermore, at least one rotating compressed-air nozzle  18  and a suction device  19  form part of the apparatus  10 . Preferably and shown in  FIG. 2 , however, the apparatus  10  has at least two units  25  with two compressed-air nozzles  18  each, which are of rotating design. The two units  25  with the two compressed-air nozzles  18  each are arranged between the ionising rods  16 ,  17  and one behind the other in the direction of travel T of the conveyor chain  11 . The rotating drive of the compressed-air nozzles  18  is effected optionally via a drive (not shown) or by means of the inflowing compressed air in conjunction with the arrangement and orientation of the compressed-air nozzles  18  themselves, this being after the fashion of a compressed-air motor. 
     The suction device  19  includes at least one, but preferably several channels  20  which surround the compressed-air nozzles  18  and the ionising rods  16 ,  17  in a ring or hood shape (see in particular  FIG. 4 ). In other words, the channels  20  surround the units  25  and the ionising rods  16 ,  17  at the sides and top, so that shielding from the environment is ensured. At the bottom, in the direction of the conveying element  12  or conveyor chain  11  to be cleaned, the channels 2D, the ionising rods  16 ,  17  and the units  25  lie exposed or open. 
     The ionising rods  16 ,  17 , the compressed-air nozzles  18  and the suction device  19  are connected to a common unit  21 . The ionising rods  16 ,  17  are connected via wires  22  to an ionising voltage supplier of the unit  21 . The compressed-air nozzles  18  are connected via pipes  23  to a compressed-air supplier of the unit  21 . The suction device  19  or its channels  20  are connected via pipes  24  to a vacuum supplier of the unit  21 . 
     To form a cleaning chamber  27 , a housing  28  is associated with the apparatus  10 . The housing  28  directly adjoins the channels  20  or the walls forming them, producing the cleaning chamber  27  which is encapsulated or at least partially partitioned off from the outside. The housing  28  has an inlet opening  29  and an outlet opening  30  for the conveyor chain  11 . The conveyor chain  11  is movable through the cleaning chamber  27 . In the embodiment shown, the actual apparatus  10  is arranged above the empty strand  13 . The housing  28 , through which the empty strand  13  is guided for cleaning purposes, is arranged essentially below the empty strand  13 , so that particles dropping down can be collected. Positioning of the apparatus  10  below and/or laterally of the empty strand  13  is also possible. In all embodiments, depending on the positioning, the housing  28  surrounds both the lower side and the upper side of the conveying element  12  or of the empty strand  13  of the conveyor chain  11 . 
     In the region of the inlet opening  29  and the outlet opening  30  are provided sealing means  33 . The sealing means  33  shield the cleaning chamber  27  outwardly from the environment. Sealing lips, brush seals or other common seals can be used as the sealing means  33 . The sealing means  33  engage laterally in horizontally extending grooves  34  in the conveyor chain  11  (see in particular  FIG. 6 ). Sealing means  33  whose contour is adapted to the contour of the conveyor chain  11  are preferred, however, so that almost complete sealing off of the cleaning chamber  27  from the environment is ensured. In the assembled state, that is, when the apparatus  10  with the housing  28  is installed, a closed system is then provided for the cleaning chamber  27 . To put it another way, a closed circuit is formed for the incoming air (as compressed air through the compressed-air nozzles  18 ) and the outgoing air. 
     In a preferred development (according to  FIG. 7 ), the guide element  14  is at least partially interrupted in the region of the cleaning chamber  27 . In other words, in the embodiment shown the conveyor chain  11  hangs free in this region. But the interruption can also be produced by apertured plates, spaced-apart guide rails or the like. 
     In  FIG. 8  can be seen different positions of the apparatus  10  within an arrangement. The apparatus  10  in  FIG. 8   a  is arranged between two guide zones of a storage device (as described in the aforementioned EP 1 445 218 A1) in which the empty strand  13  is guided, whereby the apparatus  10  is located above the empty strand  13  and the housing  28  at least partially surrounds or encloses the empty strand  13  on all sides. In the arrangement according to  FIG. 8   b,  the apparatus  10  is arranged above a guide zone of the storage device. The conveyor chain  11  itself is, in accordance with the representation according to  FIG. 8   a,  arranged within the housing  28  or guided through it. 
     In one embodiment, not shown explicitly, the apparatus  10  can also be connected to a control system. By means of the control system, automated cleaning can be carried out, for example, as a function of the degree of contamination which is definable by empirical values and/or measuring means. The control system can be used to control and/or regulate essential parameters which influence cleaning, e.g. compressed-air power, vacuum power, speed of rotation of the compressed-air nozzles  18 . The apparatus  10  can also be connected by its channels  20  or pipes  24  to a (central) dust extraction system. 
     Below, the principle of the method is described in more detail with the aid of  FIG. 2 . The empty strand  13  is fed into the apparatus  10  or, to be more precise, into the housing  28  and moved in the direction of transport T. The apparatus  10  is set in operation optionally continuously or cyclically. The ionising rods  16 ,  17  are provided with a voltage via the wires  22 , so that electrostatic charges on the surface of the conveyor chain  11  are removed. The rotating compressed-air nozzles  18  generate via the pipes  23  a turbulent air stream which can be applied continuously or in pulsed fashion. As a result, the dust particles and other contaminants are collected, swirled up and removed. Due to the at least partially open guide element  14  in the region of the cleaning chamber  27 , the compressed air also passes under the empty strand  13 , so that the conveyor chain  11  is also cleaned from below and from the side, inter alia by reflection of the compressed air on the housing wall. By the suction device  19 , the contaminated outgoing air is extracted through the channels  20  via the pipe  24  and optionally delivered to a dust separator. Both the compressed air and the outgoing air in this case circulate in a closed circuit, as the sealing means  33  essentially prevent entry of air into the cleaning chamber  27  and exit of air from the cleaning chamber  27 . 
     Instead of the conveyor chain  11 , belts or other known conveying elements  12  can also be cleaned by means of the apparatus.