Device for conveying and storing cigarettes and the like
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a device for conveying and storing streams or flow lines of rod-shaped articles, more specifically, cigarettes, by means of displaceable belts which are provided with engagement means for the cigarettes. 
     The need to convey cigarettes, either individually or in flows of cigarettes disposed parallel to and at right angles to the conveying direction arises in various sections of a production line for the manufacture and packaging of cigarettes and the like. The present invention relates specifically to the storage problem associated with the conveying of cigarettes. Cigarette storage units of the type in question are generally provided in a suitable position between the cigarette production units (extrusion machines) and the packaging machines to compensate temporary breakdowns of the machine on one side or the other by connecting in the cigarette storage unit, more specifically, by filling or emptying the same. 
     2. Description of the Prior Art 
     Various types of storage units are used for this purpose. These generally operate with rotating endless belts on which engagement means for conveying cigarettes individually or in flow lines are disposed. When cigarettes are being conveyed individually, more specifically, vertically, each cigarette is individually taken up and advanced by an engagement means. When flow lines of adjacent and superposed cigarettes are being conveyed, the engagement means penetrate the flow of cigarettes. When a cigarette flow line is vertically advanced, projecting members are disposed on each side of the belt. 
     In the conveying and storage device described in German Offenlegungsschrift 2,353,806 the belts are provided with triangular projections. These only penetrate a relatively short distance -- relative to the breadth or height of the cigarette flow -- into the flow and thereby advance the latter. This also applies to vertical flow lines. The actual engagement members consist of triangular or wedge-shaped hollow elements made of soft rubber or rubber-like material. The depth to which the engagement members penetrate the cigarette flow is about one fifth of the breadth of the flow. 
     The conveying performance of the engagement means provided in the above-described device for conveying and storing cirgarettes is inadequate. In addition, the cigarettes are not always satisfactorily protected from mechanical stressing during penetration of the engagement members into the cigarette flow. Lastly, the above-described engagement members offer only limited opportunities for varying the control of cigarette flow lines. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to so improve a device for conveying and preferably, for storing cigarettes and the like, that the cigarettes are not only handled gently but control variants for the cigarette flows, etc., adapted to the respective conditions are also available. 
     The device according to the invention which is designed to solve this problem is characterized in that the engagement members provided on the belts or the like are displaceable in such a way that they can be moved either into or out of the cigarette flow. 
     Accordingly, the engagement members according to the invention are displaceable relative to the belts from a conveying position in which they project into the cigarette flow to a generally flat position on the associated belt and vice-versa. In the latter position the engagement members, and hence also the belts, are essentially unaffected by advancement influences and thus there is no appreciable advancement of the cigarettes, particularly in the case of vertical flow lines. 
     In a preferred embodiment the engagement members are in the form of raisable hollow elements made of foldable material. These are filled with a flow medium in the raised position, more specifically, air. The engagement members consist of hollow element which can be moved into the advancement position directed generally at right angles to the belt through being inflated and which can be moved into a position in which they are not advanced by releasing or discharging the air. 
     Control of the engagement members is afforded in that the belts are divided into sections and are connected with air sources such as air tanks which are variably controllable from section to section. As a result, extensive control variability in terms of the direction of movement of the cigarettes or cigarette flows is obtained. 
     The belts equipped with engagement members of the type defined above are preferably used in devices designed for storing and conveying cigarettes. According to the invention this consists of at least two endless belts which are each equipped with engagement members and which form at least one vertical conveyor section with two oppositely disposed belts and at least one horizontal storage section. 
     The system is preferably designed in such a way that a plurality of cirgarette producing machines and packaging machines are connected together via a synchronized cooperating system of belts forming upright conveying sections and horizontal storage sections. 
     Other objects, features and advantages of the present invention will be made apparent in the following description of preferred embodiments thereof provided with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a vertical sectional view of a vertical conveyor section consisting of two oppositely disposed belts; 
     FIG. 2 is a plan view of one of the belts shown in FIG. 1; 
     FIG. 3 is a cross-sectional view on an enlarged scale through a belt in the region of an air connecting duct; 
     FIG. 4 is a perspective view of a section of a belt with the engagement members in different positions; 
     FIGS. 5 and 6 show adjacent parts of a device for conveying and storing cigarettes; 
     FIG. 7 shows the device according to FIGS. 5 and 6 on a smaller scale and in a different operating position; 
     FIG. 8 corresponds to the view shown in FIG. 7 in another operating position. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The embodiments described herein relate to the conveying and storage of cigarettes 10 which are conveyed and possibly stored in a cigarette flow 11 consisting of a plurality of adjacent and superposed cigarettes. 
     Rotating endless belts 12 and 13 are designed to convey the cigarettes 10. These belts 12 and 13, consisting, for example, of textile material coated with plastic, are designed to convey a cigarette flow 11 in a vertical direction. The belts are disposed opposite one another as a pair forming a conveyor shaft (FIG. 1). On their side remote from the cigarette flow 11, the belts 12 and 13 are laterally equipped with a denticulation 14 which ensures the drive of the belts 12 and 13. 
     The belts 12 and 13 are equipped with engagement members 15 on their side facing towards the cigarettes 10. The engagement members are suitably spaced apart from one another to obtain the desired conveying action. They are attached to the belts 12 and 13. 
     The engagement members 15 are designed so as to project into the cigarette flow 11 at right angles to the belts 12 or 13 so as to advance the cigagettes 10. They preferably extend beyond the longitudinal median plane of the cigarette flow 11. In the present case, the engagement members 15 of adjacent belts 12 and 13 are offset with respect to one another. When the belts 12,13 are driven at different rates this relative position of the engagement members 15 will vary. 
     The engagement members 15 can be moved from the conveying position (bottom of belt 12) into a neutral position in which they lie in an essentially flat position against the respective belt. Accordingly, the engagement members 15 are in the form of raisable, more specifically, inflatable hollow elements. They have a wedge-shaped cross-section. The foldable wall is provided with corresponding pre-makred fold lines 16 (FIG. 4) which make it easier to collapse the engagement member 15 in the neutral position. The engagement members 15 preferably consist of a plastic foil, a thin leather or suitable textile material. They are connected, for example, by means of adhesion, in an air-tight manner via a bottom edge 17 with the upper face of the belt 12 or 13 in the region of an opening 18 formed in the belt. Compressed air is supplied to the engagement member via this opening 18 to raise it into the engagement position shown in FIG. 4. The air is also released or discharged through this opening 18 to enable the engagement 15 to lie flat against the belt 12 or 13. 
     Air connections are provided for the engagement members 15 on the opposite sides of the belts 12 and 13 to the cirgarettes 10. In the present embodiments sections of the belts 12 and 13 are supplied in common with compressed air or air is removed in common. The air is supplied via air tanks 19 which are rigidly mounted on the rear side of the belts 12 and 13. They are spaced sufficiently far from the belts 12 and 13 to ensure that the displacement of the belts is not impaired but also that only a limited amount of air is lost. Each air tank 19 is connected via a connection line 20 with a compressed air source (not shown). 
     Owing to the fact that the belts 12 or 13 are divided, resp., the engagement members 15 are controlled in individual sections, the conveying operation can be optimally adapted to the existing conditions. The engagement members 15 lying against the belts 12,13 can be carefully moved by means of compressed air into the cigarette flow 11 without damaging the cigarettes 10, namely in the region of an air tank 19. If an engagement member 15 which is raised in the conveying position reaches an air tank 19 from which the air has been released or which is connected to a vacuum source, that particular engagement member is removed from the cigarette flow 11 until it rests in an essentially flat position on the belt 12 or 13. This rest position of the engagement members 15 is such that even when a belt (in FIG. 1, belt 13) is displaced in the opposite direction to the conveying direction of the cigarette flow 11, a conveying influence is not exerted on the cigarette flow 11. 
     Owing to the multiple control features the engagement members 15, resp., the belts 12,13 equipped with these engagement members, can be used for many different purposes. FIGS. 5-8 show an embodiment of a conveying and storage system wherein a plurality, namely three cigarette producing machines 21,22,23 are associated with a plurality more specifically two packaging machines 24 and 25. These production and processing units are connected together by a plurality of belts 12,13 equipped with engagement members 15 in such a way that a plurality of storage units are formed. According to the particular conditions, these are able to compensate over-production on the production side or counteract under-production. 
     The design of the system is such that vertical conveying sections 26,27,28,29,30 are disposed between the cigarette producing machines 21,22,23 and the packaging machines 24 and 25. These vertical conveying sections each consist of two oppositely disposed belt sections. These are, in turn, formed by a plurality of rotating belts 31,32,33,34,35, 36.The afore-mentioned belts pass over partially driven deflecting rollers 37. The belts 31,33 and 35 are each equipped with four deflecting rollers and the belts 32,34 and 36 with five deflecting rollers. 
     The belts 31-36 are divided by the deflecting rollers 37 into horizontal and vertical sections which are, in turn, associated with air tanks 19 extending over one such section. The connecting ducts 20 to these air tanks 19 lead to a common compressed air source or vacuum source. Blocking elements or valves are disposed in the connecting ducts 20. These blocking elements 38 provide individual control of the sections associated with the relevant air tanks 19. 
     In the present case the outer belts 31 and 36 are in the form of storage units. The belt 31 comprises a horizontal storage section 39 and a vertical storage section 40. The latter cooperates with a vertical counter element 41 which is not provided with an engagement member. The storage unit of the belt 36 is formed by an upper horizontal storage section 42. 
     FIGS. 5 and 6 show an operating position wherein the central cigarette production machine 22 is temporarily out of action. The belts 33 and 34 are controlled in such a way that the engagement members of the vertical conveying section 27 lie flat against the respective belts, i.e., do not perform a conveying function although the belt sections in question are vertically displaced with the belts 33 and 34. Accordingly, no cigarettes are conveyed in the region of the conveying section 27. The packaging machines 24 and 25 are supplied by the cigarette producing machines 21 and 23. The difference, namely a third of the quantity taken up by each packaging machine 24 and 25, is removed from the storage unit 39/40 or 42. The engagement members of the belts 31 and 32 and also 35 and 36 are thus extended into the storage zone. As a result, partial cigarette flows 43 and 44 or 45 and 46 are combined in the region of the belts 32 and 35. Guide rollers 47 are mounted above the conveying sections 26,27 and 28 to ensure correct transfer and adjustment of the partial flows. 
     The operating state shown in FIG. 7 proceeds from stoppage of the packaging machine 24. As the cigarette machines 21-23 continue to supply cigarettes, an excess of cigarettes must be supplied to the storage units. This is achieved in that the quantity of cigarettes supplied by the cigarette producing machine 23 remains unchanged and is supplied by the belt 35 directly to the packaging machine 25. The packaging machine is not yet fully loaded thereby, but a partial flow 48 is additionally supplied from the cigarette producing machine 22 by the belt 34. The other partial flow 49 from this cigarette producing machine is supplied by the belt 33 and the adjacent belt 32 to the storage unit 39/40. The full capacity of the cigarette producing machine 21 is also supplied to the storage unit via the belt 31. 
     The air is released from the vertical belts sections of the belts 32 and 33 associated with the conveying section 29 such that the engagement members 15 of the rotating belts 32 and 33 do not exert a conveying action in the region of conveying section 29. Similarly, the downwardly displaced section of the belt 32 in the region of the conveying section 26 is switched to evacuated engagement members 15 such that the cigarettes in this conveying section 26 can be moved upwards by the belt 31 inspite of the oppositely directed section. 
     The operating state shown in FIG. 8 occurs when the cigarette producing machine 21 is interrupted. The resulting lack of cigaretes is compensated by the storage unit 39/40. A quantity of cigarettes corresponding to the output capacity of the cigarette producing machine 21 is removed by the belt 31 from the storage unit and supplied via the belt 32 to the packaging machine 24. The latter also receives a partial flow 49 from the cigarette producing machine 22. The other partial flow 48 of production machine 22 is supplied to packaging machine 25 via the belt 34. The output of cigarette producing machine 23 is supplied in its entirety to the packaging machine 25 via the belt 35. 
     As in the case of the operating state shown in FIG. 7, the belt 36 can be switched to the inoperative state. The vertical sections of belts 31 and 32 are switched to the inactive position of the engagement members 15 in the region of the conveying section 26. 
     The above arrangement can also be used in other combinations, for example, packaging machines having a reduced capacity or with more packaging machines and cigarette producing machines. 
     The air tanks 19 are associated with the respective belt sections in such a way that the engagement members 15 can be moved gently into the cigarette flow 11. This applies, in particular, to the area of the lower deflecting rollers 37 of conveying sections 26,27 and 28. The deflection of the air tanks 19 in this region is such that the engagement members are increasingly raised during the movement of the belts about the deflecting rollers 37 and penetrate the cigarette flow 11. 
     In the embodiment shown in FIGS. 5-8 the disposition of the individual belts 31-36 is such that the units consisting of two belts 31 and 32,33 and 34, 35 and 36 are associated with each cigarette producing machine 21,22,23. The belts for these units form with the belts of the adjacent unit vertical conveyor section 29 and 30 which is represented. The length of the belt sections for the latter conveyor sections 29 and 30 is greater than the length of the belt sections for conveyor sections 26,27,28. The latter merely have to receive the output of a cigarette producing machine 21,22,23 whereas conveyor sections 29 and 30 must convey the--higher--output of a cigarette producing machine 21 or 22 and 23. 
     The ducts 20 leading to the air tanks 19 are connected with a compressed air resp., vacuum source having a high conveying capacity with slight under or over-pressure. They preferably make use of commercially available fans having a corresponding capacity.