Abstract:
A method for pressing together empty containers, especially drinks bottles or cans made of plastic, especially PET or tinplate, comprises a housing with a fill opening and an outlet, a cutting and pressing disposed in the housing, and a device for driving and controlling the cutting and pressing unit. The cutting and pressing unit contains at least two rollers whose axes of rotation are arranged at a distance from each other. Each roller has at least two sections. Adjacent sections along the same roller have different diameters. When the rollers are mounted, the sections having the larger diameter are offset relative to each other and the peripheral surfaces thereof partially overlap with each other, forming cutting disks whose peripheral surfaces have at least one groove.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Applicant claims priority under 35 U.S.C. §119 of German Application Nos. 103 20 509.8, 103 25 368.8, 103 53 188.2, filed Apr. 27, 2003, May 26, 2003 and Nov. 13, 2003 respectively. Applicant also claims priority under 35 U.S.C. §365 of PCT/EP2004/004120 filed Apr. 19, 2004. The international application under PCT article 21 (2) was not published in English. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a device as well as a method for pressing together empty containers, particularly beverage bottles or cans and similar waste material. 
     Such devices are used to compact empty containers, particularly those from the foods sector, such as beverage bottles, cans, and similar containers, for transport to recycling facilities or for the recycling process itself. 
     For one thing, devices that work according to the principle of plate pressing are known, and for another, those whose pressing unit(s) contain rollers are known. These devices are optimized either for the treatment of plastic containers or of tin plate containers or cans. 
     Since the said waste goods can also contain closed containers, in a not insignificant number, a perforator often precedes the pressing device(s) of these devices, e.g. a perforator according to DE 43 38 561 A1 or U.S. Pat. No. 5,642,661 A. 
     In order to be able to reduce the technical effort and expense in the case of these devices, devices are also known in which means for perforation are provided on the pressing parts of the pressing device(s), e.g. in the case of a device for compacting empty beverage containers according to DE 100 55 201 A1. This device possesses a conveyor segment that narrows in essentially funnel shape, into which the beverage containers enter and are successively compacted under the effect of devices for transporting them and pressing them together, which delimit the conveyor segment on the sides. 
     Furthermore, it is provided that there the rollers are equipped with blade-shaped elevations that are distributed on their circumference, which extend over the length of the rollers, in other words parallel to their axis of rotation. Furthermore and in particular in the case of this device, the devices for transporting and pressing together the beverage containers consist of rollers driven by drum motors. 
     This device is expensive and maintenance-intensive, particularly because of the modules last mentioned. 
     Another disadvantage results if the distance between the rollers, which are disposed in pairs, particularly those having the least distance between axes, is not precisely adjusted with regard to the distance between them and the position of the blades, which are oriented longitudinally. In this case, cutting of the material that is passed through takes place, so that smaller pieces are formed from a bottle or can, in each instance. Such small and very small pieces are very difficult to process further into bales, if this can even be done at all; additional containers are then required for their transport. 
     SUMMARY OF THE INVENTION 
     Proceeding from this state of the art, a person skilled in the art is confronted with the task of configuring a device for pressing together empty containers, particularly beverage bottles or beverage cans made of plastic, particularly PET bottles, or tin plate, in such a manner that pressing them together is reliably guaranteed, and that the production costs and maintenance effort and expense for these devices can be reduced as compared with known devices, and furthermore, an improvement in the method is being sought. 
     According to the invention, this task is accomplished by means of a device for pressing together empty containers comprising a housing having a fill-in opening and exit opening, a cutting and pressing unit disposed in the housing, the cutting and pressing unit containing at least two rollers that are disposed at a distance from one another with reference to their axes of rotation, and means for driving and controlling the cutting and pressing unit. Each of the rollers, when viewed in a direction along the axis of rotation, has at least two segments, and segments that alternately follow one another along the axis possess different outside diameters from each other. When the rollers are installed, the segments having a larger outside diameter in each roller are offset relative to one another and are disposed with their circumferential surfaces partially overlapping one another, thereby forming cutting disks whose circumferential surfaces each possess at least one groove. 
     The core idea of the invention consists in the fact that with the new device, the said containers are perforated and pressed together at almost the same time, using only one pair of rollers. The means for perforation are configured in such a manner and disposed on each of the two (pressing) rollers, preferably integrated into the latter, particularly an integral part of their bodies themselves, so that according to the method, wall segments into which cuts have been made hook into the wall segments of a container that is being pressed against them, while the flattened material is being cut in segments and/or immediately afterwards, quasi in the end phase of such a cut. In this way, the container&#39;s tendency to expand again after being pressed, which is determined by its original body shape, the elasticity values of the container material, and the pressing process, is counteracted. 
     Furthermore, on at least one of the rollers of the new device, the means for pressing together are shaped, and disposed in their position relative to the means for pressing together provided on the roller that is positioned essentially parallel opposite, in such a manner that the outer surface of the container, viewed in the crosswise direction to its transport direction, is partially cut or at least partially slit at least in segments. In this way, tensions in the material that are present there are released, and therefore the tendency of the container to expand again after it has been pressed together is also counteracted. 
     Furthermore, the handling of plastic containers, particularly those of PET material, and of containers made of tin plate, is made possible in the said manner, one immediately after the other, without additional adjustments to the device, by means of the new device. 
     The new device for pressing together empty containers, particularly beverage bottles or cans made of plastic or tin plate, consists of a housing having a fill-in opening as well as an exit opening (outlet opening) and a cutting and pressing unit disposed in the housing. Furthermore, means for driving and controlling the cutting and pressing unit are provided, whereby the cutting and pressing unit contains at least two rollers that are disposed at a distance from one another with reference to their axes of rotation. Each of the two rollers has several disks disposed at an axial distance from one another, the working disks. 
     Particularly, it is provided, on this cutting and pressing unit, that each roller, viewed in the longitudinal direction of its axis of rotation, has at least two, preferably more segments, whereby at least one segment of these segments, which alternately follow one another, possesses one or more disks that are spaced axially apart, and whereby these consecutive segments possess a different outside diameter, in each instance, and, in the installed state of the two rollers, at least the segments having the larger diameter are offset relative to one another and are disposed with their circumference surfaces partially meshing (overlapping) next to one another, and thereby form cutting disks. Preferably, at least one groove is provided in the circumference surface of at least one of these cutting disks, which passes through both cutting disk flanks. 
     Preferably, the length of the segments having the greater diameter is less than the length of the segments that possess one or more disks having a smaller diameter. Preferably, the diameter of the larger disks is 79 mm, the diameter of the longer segments—the pressing regions—is 70 mm, and the core diameter of the rollers is 50 mm. 
     An advantageous embodiment of the invention also consists in the fact that the segments having the smaller outside diameter also possess at least two recesses that are directed radially inward, reaching to the core diameter, in such a manner that at least one pressure disk is formed. Preferably, however, several pressure disks are worked into the segments having the smaller diameter, which disks are spaced apart from one another by the width of the recess. 
     Preferably, at least one groove is provided in the circumference surface of at least one of these pressure disks, whereby each groove that is provided passes through both flanks of the pressure disk in question. 
     According to another embodiment, strippers are disposed between the disks, whereby standard strippers of document shredders can be used. 
     Since it is supposed to be possible to reliably press together both beverage bottles or beverage cans made of plastic, particularly PET bottles, as well as containers made of tin plate, the requirements to be fulfilled are also of many kinds. In the case of the activities for solving the problem—the theoretical considerations and the practical experiments—it turned out that not only the design (shape) and the number of cutting disks are important in themselves, but also, the dimensioning of the so-called cutting play between adjacent cutting disks and the material used for the cutting rollers have a positive or negative effect on the performance parameters of such a device, including its availability and maintenance effort and expense. A positive effect is achieved if this cutting play has a value between 0.2 mm and 2 mm between adjacent disks, and/or the overlap between adjacent and opposite disks is selected to be between 0.5 mm and 2.5 mm, preferably 10% of the width of a disk. 
     The rollers of the device preferably consist of the material 42CrMoS4. The disks of the rollers are hardened and maximally have a hardness of 55 HRc. 
     According to a special embodiment of the grooves formed in the circumference surface of the cutting disk(s), the trailing flank, in the direction of rotation, forms an acute-angle hook with the circumference surface, which points in the direction of rotation, whereby the groove flank that starts at the tip has a linear progression as well as a progression that is directed opposite the direction of rotation of the roller, at least in segments, and the subsequent transition region is configured in arc shape towards the groove toe and/or the groove flank that lies in the circumference direction. Preferably, the two groove flanks run parallel to one another or divergent. The tip angle of the hook is preferably selected to be between 45° and 80°. 
     In another preferred embodiment, the rollers rotate at a speed of 60 rpm. It is furthermore provided that the start pulse for the rollers is issued by way of a photo eye, and that an after-running time is provided. 
     Furthermore, it is provided, in the case of the new device, that the cutting and pressing unit is preceded by a separator in the region of the fill-in opening, which comprises, in a preferred embodiment, a supply container having a funnel-like shape. Blades rotate around an axis of rotation of the separator, preferably three or four blades, which pass the waste goods to the cutting and pressing unit in the transport direction, in orderly manner and, at the same time, press the waste goods into the intake gap of the cutting and pressing unit, at least until the containers are seized by the cutting disks. Above the cutting mechanism and behind the separator, one of the walls of the funnel is continued, or a plate-like part is disposed, to delimit the supply area and as a guide surface for passing any containers that might have passed through under the blades or been dragged along back to the supply area. 
     Other advantageous design details of the new device are the bearings for the rollers that are inserted into the bearing plates from the outside. This is advantageous because it cannot be precluded that containers are closed and furthermore still contain liquid, which in turn can ferment, so that a pressure is built up in the bottle and this liquid sprays about, in uncontrolled manner, in the cutting and pressing unit, during the first perforation. 
     Because of the latter, nozzles are provided in the housing of the device, to apply disinfectant to the rollers and/or the inlet and outlet openings. 
     The outside dimensions of the device are such that it can be coupled to automated devices for accepting bottles and/or cans for recycling. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following description part, the invention will be explained in greater detail using advantageous exemplary embodiments schematically shown in drawings. These show: 
         FIG. 1  a device according to the invention in a side view, with the side surface partially opened, and a view of the cutting and pressing unit, 
         FIG. 1   a  shows the device according to the invention connected with an automated device for accepting bottles and/or cans for recycling. 
         FIG. 2  a schematic view from the side of the two rollers, with the front (left) bearing plate removed, 
         FIG. 3  the first (front) roller in a top view, without drive wheel, 
         FIG. 3   a  the position of the two rollers relative to one another, 
         FIG. 4   a  a view of the drive side of one of the rollers, 
         FIG. 4   b  a face view of  FIG. 4   a,    
         FIG. 4   c  a side view of  FIG. 4   a , without the cutting disk, 
         FIG. 5  a detail of a cutting disk, with another variant of the groove configuration, 
         FIG. 6  another variant of the separator that precedes the rollers, which assumes a press-down function at the same time, and 
         FIGS. 7 and 7   a  other variants of the blades of the metering and press-down shaft shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The new device for pressing together empty containers is shown schematically in  FIG. 1 , in a side view, with a partially opened side surface and a view of the cutting and pressing unit. The device comprises a housing  1 , having a fill-in opening  2  in its front side  1 . 2 , as well as an exit opening  3 , also called an outlet opening, in its bottom side  1 . 3 , and a cutting and pressing unit  4  disposed in the housing  1 , as well as means for driving and controlling the cutting and pressing unit  4 , which are not shown here. The top side  1 . 1  and the rear side  1 . 4  of the housing  1  are closed in this exemplary embodiment. 
     The cutting and pressing unit  4  contains two rollers  4 . 1  and  4 . 2  that are disposed at a distance from one another with regard to their axes of rotation. Each roller  4 . 1  and  4 . 2  has two, preferably several segments S 1  and S 2 —see  FIG. 2 to 3   a  in this regard—viewed in the longitudinal direction of their axes of rotation A 1  and A 2 , respectively, whereby segments that alternately follow one another each possess a different outside diameter D 1 , D 2 , in each instance and, in the assembled state of the two rollers  4 . 1  and  4 . 2 , at least the segments S 2  that possess the larger outside diameter D 2  are disposed offset relative to one another and partially meshing (overlapping) with their circumference surfaces, next to one another, and thereby form cutting disks  5 , the circumference surfaces  5 . 1  of which possesses at least one groove, in each instance. 
     A slide  9  is provided in front of the lower edge of the fill-in opening  2 , towards the cutting and pressing unit  4 , on which the containers G 3 , G 2 , or G 1  roll or slide to reach the unit  4 . Above this slide  9 , a separator  10  is positioned, which passes the containers G 3 , G 2 , or G 1  to the unit  4  in the transport direction F, with its blades  12 , here three, that rotate about an axis of rotation  11 , in orderly manner and, at the same time, presses them into the intake gap of the cutting and pressing unit  4 , at least until the containers are seized by the cutting disks  5 . Dk refers to the circumference circle described by the ends of the blades  12 . Above the cutting and pressing unit  4  and behind the separator  10 , a plate-like frame part  13  is disposed to delimit the accommodation space. The region of the exit of the objects treated in the cutting and pressing unit  4  has the reference symbol  7 . 
     The length L 2  of the segments S 2  having the larger outside diameter D 2  is less than the length L 1  of the segments S 2  that possess the smaller outside diameter D 1 . 
     The segments S 1  that possess the smaller diameter D 1  possess at least two recesses E that are directed radially inward, up to the core diameter  4 . 3 , in such a manner that at least one pressure disk  6  is formed. 
     Preferably, several pressure disks  6  are provided in the segments S 1  that have the smaller diameter D 1 , which disks are spaced apart from one another with the width B 3  of the recess E, in each instance. The so-called cutting play  16  between adjacent disks  6  or  5  and  6 , in other words their side surfaces  6 . 2  or  5 . 2 , respectively, see  FIG. 3   a , has a value between 0.2 mm and 2 mm. 
     B 1  refers to the width of the pressure disks  6 ; B 2  refers to the width of the cutting disks  5 . 
     The overlap of adjacent and opposite disks is selected to be in a value range between 0.5 mm and 2.5 mm; preferably, this overlap amounts to 10% of the width of a disk  5  or  6 , respectively. 
     The disks of the rollers  4 . 1  and  4 . 2  are hardened and possess a maximal hardness of 55 HRc. 
     The left end region of the roller  4 . 1 , in this figure, is shaped as a bearing journal  4 . 4 , and the right end region as a bearing and drive journal  4 . 5 . 
     In the case of the embodiment shown in  FIGS. 1 and 2 , the bearings of the rollers  4 . 1  and  4 . 2  are inserted into the bearing plates  8  from the outside, and preferably also sealed towards the inside, towards the working space. This design is particularly wear-resistant and maintenance-friendly. 
     Details of the segments S 1  and S 2  as well as of the configuration of the rollers are shown in  FIG. 3 and 3   a . Preferably, the diameter D 2  of the segments S 2  is 79 mm, the diameter D 1  of the smaller segments S 1  is 70 mm, and the core diameter  4 . 3  of the rollers  4 . 1  and  4 . 2  is 50 mm. 
     The speed of rotation of the rollers  4 . 1  and  4 . 2  of the cutting and pressing unit  4  is preferably 60 rpm. The start pulse for the rollers  4 . 1  and  4 . 2  is preferably issued by way of a photo eye  20 ; furthermore, an after-running time is also predetermined with this control component, so that all of the containers that have been fed in always leave the cutting and pressing unit. When the rollers are at rest, there are therefore no containers between same; adhesions caused by residual contents of the containers, and unnecessary stress on the cutting regions of the cutting disks are avoided. 
       FIGS. 1 and 2  also show that in the case of this embodiment, strippers  4 . 6  are disposed between the disks  5  and  6 , whereby standard strippers of document shredders are used. 
     Nozzles  22  are disposed in the housing  1  to apply disinfectant and/or cleaner to the rollers  4 . 1  and  4 . 2  and/or the inlet opening  2  and the outlet opening  3 , so that any odor formation promoted by liquid residues and the ambient atmosphere (bacteria formation) can be prevented. 
       FIGS. 4   a  to  5  show exemplary embodiments for the detailed configuration of the cutting disks  5  and the pressure disks  6 , as well as the grooves disposed in the cutting disks  5 . 
     According to  FIG. 5 , the trailing flank FL of the grooves  5 . 3  disposed in the circumference surface  5 . 1  of the cutting disks  5 , in the direction of rotation R, R′, forms an acute-angle hook  5 . 4  with the circumference surface  5 . 1 , which points in the direction of rotation, whereby the groove flank FL that starts at the tip S has a linear progression as well as a progression that is directed opposite the direction of rotation of the rollers R, R′, and the subsequent transition region K is configured in arc shape towards the groove toe N and/or the groove flank F 1 L or F 2 L that lies in the direction of rotation. 
     Preferably, the two groove flanks FL and F 1 L run parallel to one another or divergent FL, F 2 L. The tip angle W of the hook  5 . 4  is preferably selected to be between 45° and 80°. 
       FIG. 4   a  shows the right segment of the second roller  4 . 2 , the rear roller shown in  FIG. 3   a . The bearing and drive journal provided in this end region is designated as item  4 . 5 . A cutting disk  5  is flanked by a pressure disk  6  on both sides. Grooves  6 . 3  and  5 . 33 , respectively, are disposed in the circumference surface  6 . 1  and  5 . 1 , respectively, which break up their side surfaces  6 . 2  and  5 . 2 , respectively. 
     A face view of  FIG. 4   a  is shown in  FIG. 4   b , with a view of the side surface  6 . 2  and the hooks  5 . 4  of the cutting disk  5  disposed behind it.  FIG. 4   c  shows a face view of  FIG. 4   a , in which the cutting disk  5  was left out in the representation of the component being considered, in order to be able to show the formation of the grooves  6 . 3  in the pressure disk  6  more clearly. As shown schematically, the depth of the grooves  6 . 3  is significantly less, as compared with the depth of the grooves  5 . 3 . 
       FIG. 6  shows another variant of a separator. This separator  14  possesses two star-shaped shafts, viewed in the side (face) view, the direction of rotation of which is the same as that of the related rollers. 
       FIGS. 7 and 7   a  show other variants of the blades of the separator  10 . Proceeding from the center, the axis of rotation  11 , these blades are shaped in a polygon progression  17  or in arc shape  18 . These embodiments guarantee, even better than the basic variant, that the containers being passed in, particularly containers having a volume between 0.25 liters and 3 liters, receive an optimal contact pressure in the direction of the intake gap of the cutting and pressing unit  4 . As is furthermore evident from these two figures, the end regions of the blades  17  and  18 , respectively, are fitted with stabbing elements  19 . The tip of these stabbing elements  19  points in the direction of rotation, in other words in the working direction. By means of this measure, holding and guiding the containers to the intake gap of the cutting and pressing unit  4  is improved even more. Particularly in the case of containers that have very thin walls or are very flexible, it can happen, under some circumstances, that the blade ends could slip past such a container. These stabbing elements  19  counteract such a tendency. 
     In the case of the embodiment according to  FIG. 1 , connector fittings  15  are provided on the front side  1 . 2 , in the region of the fill-in opening. These are affixed there in case the device is supposed to be coupled with an automated device  21  for accepting bottles and/or cans for recycling, such as shown in  FIG. 1   a.    
     All of the characteristics mentioned in the above description, as well as those that can be derived solely from the drawings, are further integral parts of the invention, even if they are not particularly emphasized and, in particular, are not mentioned in the claims. 
     The invention is not restricted to the exemplary embodiment described, but rather is variable in many different ways, within the scope of the disclosure. 
     
       
         
               
             
               
               
             
           
               
                   
               
               
                 Reference Symbol List 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 housing 
               
               
                 1.1 
                 top side (surface) 
               
               
                 1.2 
                 front side 
               
               
                 1.3 
                 bottom side 
               
               
                 1.4 
                 rear side 
               
               
                 2 
                 fill-in opening 
               
               
                 3 
                 outlet opening (exit opening) 
               
               
                 4 
                 cutting and pressing unit 
               
               
                 4.1 
                 first roller (front) 
               
               
                 4.2 
                 second roller (rear) 
               
               
                 4.3 
                 core diameter 
               
               
                 4.4 
                 bearing journal 
               
               
                 4.5 
                 bearing and drive journal 
               
               
                 4.6 
                 stripper 
               
               
                 5 
                 cutting disks 
               
               
                 5.1 
                 circumference surfaces 
               
               
                 5.2 
                 side surfaces 
               
               
                 5.3, 5.33 
                 grooves 
               
               
                 5.4 
                 hook 
               
               
                 6 
                 pressure disks 
               
               
                 6.1 
                 circumference surface 
               
               
                 6.2 
                 side surface 
               
               
                 7 
                 exit 
               
               
                 8 
                 bearing plates 
               
               
                 9 
                 slide 
               
               
                 10 
                 separator 
               
               
                 11 
                 axis of rotation of item 10 
               
               
                 12 
                 blade(s) 
               
               
                 13 
                 frame part (delimitation of the accommodation space 
               
               
                   
                 towards the rear) 
               
               
                 14 
                 separator (selector) 
               
               
                 15 
                 connector fitting(s) 
               
               
                 16 
                 cutting play 
               
               
                 17 
                 blade, polygon progression 
               
               
                 18 
                 blade, arc-shaped 
               
               
                 19 
                 stabbing elements (sharp screws, nails, or a similar part) 
               
               
                 A1 
                 axis of rotation of the roller 4.1 
               
               
                 A2 
                 axis of rotation of the roller 4.2 
               
               
                 B1 
                 width of item 6 
               
               
                 B2 
                 width of item 5 
               
               
                 B3 
                 width of the recesses 
               
               
                 D1 
                 diameter of the segments S1 (outside diameter) 
               
               
                 D2 
                 diameter of the segments S2 (outside diameter) 
               
               
                 Dk 
                 circumference circle of the blades according to FIG. 1 
               
               
                 E 
                 recesses 
               
               
                 F 
                 transport direction 
               
               
                 FL 
                 flank 
               
               
                 F1L 
                 flank 
               
               
                 F2L 
                 flank 
               
               
                 N 
                 groove toe 
               
               
                 K 
                 transition region 
               
               
                 W 
                 tip angle 
               
               
                 G1, G2, G3 
                 containers having different diameters 
               
               
                 S 
                 tip of item 5.4 
               
               
                 S1 
                 segments 
               
               
                 S2 
                 segments 
               
               
                 L1 
                 length of the segments S1 
               
               
                 L2 
                 length of the segments S2 
               
               
                 R 
                 direction of rotation (turning direction) 
               
               
                 R′ 
                 direction of rotation (turning direction)