Patent Publication Number: US-6701600-B1

Title: Method and device for machining cylindrical hollow bodies

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is the national stage under 35 U.S.C. 371 of PCT/DE00/00729, filed Mar. 8, 2000. 
    
    
     The present invention relates to a method for producing or machining a work piece in the form of a cylindrical hollow body, especially a container (a wall of a container), a barrel or a cask, whereby the work piece is held such that the longitudinal axis thereof is oriented vertically and then machined in this orientation, especially formed, edged, and provided with beads, a bottom and a lid. The invention furthermore relates to a device for producing or machining a work piece in the form of a cylindrical hollow body, especially a container (a wall of a container), a barrel or a cask, having a transfer apparatus for moving the work piece, and a machining apparatus for producing or machining the work piece, especially an apparatus for forming, edging and providing with beads, a bottom and a lid, and with means for holding the work piece during the machining process in an orientation in which the longitudinal axis of the work piece is oriented vertically. The machining takes place on one or more, or preferably simultaneously on both front edges of the work piece. The machining may consist of grooving, edging or attaching a lid or bottom. For example, a drum-shaped metal shell or a wall of a container serving as a packaging container for any random filled-in contents with a loosely inserted bottom and lid may be firmly closed, with the closing process consisting of cold forming or warm forming in such a way that projecting metal edges are connected to one another, or formed and folded together. 
     In devices according to the preamble, in which the center axes of the work pieces are oriented vertically during the production or processing or forming, a transportation or transfer line is located underneath the machining apparatuses in such a way that the work pieces that are to be machined are moved by the transportation apparatus or by hand into the working area of the tools that are arranged or hanging above it. 
     The known method has the shortcoming that the heavy tools and drive assemblies must be mounted to portals having the appropriate load capacities, which results in considerable expenditures. 
     It is the object of the present invention to render a method according to the preamble, or a corresponding device, simpler and more cost effective. 
     With regard to method, this object is met in a method according to the preamble in such a way that the work piece is moved within a transfer level and lowered into a working area of a machining apparatus, especially a forming machine, that is arranged underneath the transfer level, for the machining process. This permits the heavy drive assemblies and forming tools to be mounted advantageously near the ground, while a light-weight transfer apparatus for moving the work pieces is located above them. 
     The work piece is lowered for the machining process with its longitudinal axis oriented vertically, and moved within the transfer level with its longitudinal axis oriented vertically. The work piece may be machined in the machining apparatus from the inside and/or from the outside. The work piece may be machined in the machining apparatus along its entire axial length or along a portion thereof. The work piece may be lowered and machined in stages. 
     The work piece may be lifted after a machining step and moved back into the transfer level, with the work piece undergoing a number of machining steps (lowering, machining and lifting) in a plurality of machining apparatuses. The work piece may be moved past selected machining apparatuses without being machined. Work pieces or containers may be manufactured noncircular or conical, and work pieces may be manufactured of sheet metal, multilayered sized cardboard (fiber) or multilayered metal-plastic sheets. 
     With regard to the device, the object of the invention is met with a device according to the preamble that is characterized in that the transfer apparatus is arranged vertically above the machining apparatus and designed such that a work piece that is to be machined can be lowered into a working area of the machining apparatus. The transfer apparatus may move and/or lower the work piece with its longitudinal axis oriented vertically. 
     The machining apparatus advantageously machines the work piece from the inside and/or from the outside especially in such a way that it edges the work piece on both sides, or edges it on one side and flanges it on the other side. The machining apparatus preferably provides the work piece with rolled beads and/or reinforcing beads. 
     A plurality of machining apparatuses may be arranged in series. 
    
    
     The invention will be explained in more detail below, based on a drawing in which: 
     FIGS. 1 and 2 serve to schematically illustrate a container that is to be machined; 
     FIG. 3 schematically shows an inventive device; 
     FIG. 4 schematically shows a known device wherein a work piece is machined with its longitudinal axis oriented vertically; 
     FIG. 5 schematically shows a known device wherein a cylindrical work piece is machined with the work piece axis oriented horizontally, and 
     FIG. 6 is a top view of a known forming tool. 
    
    
     FIG. 1 shows a rounded wall of a container that is closed with a longitudinal weld or a longitudinal fold and may consist of sheet steel or some other sheet metal, but also of fiber (multilayered sized cardboard) or multilayered metal-plastic sheets. FIG. 2 shows a cylindrical container with a longitudinal axis  1  made from the container wall shown in FIG. 1, said container having a cylindrical container wall  4  provided with rolled beads  2  and reinforcing beads  3 , and a bottom  5 . 
     FIG. 4 shows, in a schematic illustration, a container production machine, in which the center axis or longitudinal axis  1  of a container stands vertically during the forming or production, with the container wall  4  lifted, for the forming process, by a transfer apparatus  7  or by hand into the working area of a machining tool  8  hanging from a portal above the transfer apparatus. 
     FIG. 5 illustrates a further known manufacturing method for containers whereby a container wall  4  with a horizontal longitudinal axis  1  is machined, whereby tools  8   a  machine the container wall  4  from the inside, and tools  8   b  machine the container wall from the outside so that beads, for example, may be formed. 
     FIG. 3 explains the inventive method based on a device wherein the work pieces or the container walls  4  with the vertically oriented longitudinal axis  1  can be lowered by a transfer apparatus  7  between forming tools  8   a ,  8   b  arranged on a machine bed  10 . 
     Depending on the shaping to be performed, the lowering may take place with the full length of the container wall, or in stages, via parts thereof. The drive assemblies and forming tools are located just above the ground, while the light-weight transportation or transfer apparatus  7  is arranged above the machine. A plurality of forming machines may be arranged in series, and the individual machines may be designed for a double-sided edging (upsetting of the edge), one-sided edging and flanging (rolling of the edge) on the other side, press-forming of any number of rolled beads in various positions on the container wall, roll forming of any random number of reinforcing beads in different positions, lock-seaming bottoms and/or lids, or welding on lids. The containers or container walls that are moved in the transportation direction (arrow  12 ) on the transfer apparatus  7  are lowered (arrow  14 ) over the tools of the given machines and, after the forming or machining, lifted back onto the transfer apparatus. Individual forming machines may be bypassed and skipped for the manufacture of different container or container wall shapes. 
     The container wall guide elements are simpler and less complicated in the inventive design (lowered forming level), and also permit the forming of non-circular or conical container walls. 
     FIG. 6 shows an example from the prior art (EP 0 356 269) for a design of the forming tools  8   a ,  8   b  used in the device. The device has a roller  32  and a counter roller  31 , with the two rollers created complementary to one another and the counter roller  31  mounted stationary. The roller  32  is held pivotable around a pivot point  37 . The outer surfaces of the rollers are assembled from a number of ring-shaped disks  33   a ,  35   a ,  35   b . 
     
       
         
           
               
             
               
                   
               
               
                 List of Reference Numerals 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                  1 
                 Longitudinal axis 
               
               
                   
                  2 
                 Rolled bead 
               
               
                   
                  3 
                 Reinforcing bead 
               
               
                   
                  4 
                 Container wall 
               
               
                   
                  5 
                 Bottom 
               
               
                   
                  7 
                 Transfer apparatus 
               
               
                   
                  8 
                 Machining tool 
               
               
                   
                  8a, 8b 
                 Machining tools 
               
               
                   
                 10 
                 Machine bed 
               
               
                   
                 12 
                 Transportation apparatus 
               
               
                   
                 14 
                 Lowering apparatus 
               
               
                   
                 31 
                 Counter roller 
               
               
                   
                 32 
                 Roller 
               
               
                   
                 33a, 35a, 35b 
                 Ring-shaped disks 
               
               
                   
                 37 
                 Pivot point