Abstract:
A glass sheet forming system ( 10 ) has two parallel forming lines ( 12 ) that can utilize any two of three forming stations ( 18 ) to provide versatility in use for forming different glass sheet jobs of different sizes and shapes while reducing switchover time from one job to the next.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates to a glass sheet forming system that has versatility in use for economically forming different glass sheet jobs of different sizes and shapes. 
       BACKGROUND 
       [0002]    Glass sheet forming systems conventionally include a furnace for heating glass sheets for forming, a forming station that cyclically receives the heated glass sheets from the furnace to provide the forming and a cooling station located downstream from the forming station to provide cooling that may be slow cooling for annealing, faster cooling for heat strengthening or rapid cooling for tempering. The most efficient operation of such glass sheet forming stations takes place with the least possible downtime between switching from one job to another. Such job switching was originally accomplished by changing one or more molds utilized to provide the glass sheet forming, but such mold switching changes require significant downtime, four to six hours or more, that necessarily increases the cost of each formed glass sheet produced. To reduce the downtime, a pair of forming stations that can be moved sideways along the length of the glass sheet forming system for use of one or the other have also more recently been utilized, which is more economical than having two systems because the cost of the forming stations relative to the cost of the furnaces and cooling stations is much less and reduces the downtime since any mold changing can be performed when another production job is being performed. 
         [0003]    Prior art glass sheet forming systems are disclosed by: U.S. Pat. No. 6,573,484 Bennett et al. which discloses that the furnace can also include a roll bending station with inclined rollers that preform the glass sheet prior to conveyance to the forming station for further forming; U.S. Pat. No. 6,543,255 Bennett et al. which discloses a roll bed having detachable drive wheel assemblies that permit a lower press ring of varying shapes to be utilized in the forming; and U.S. Pat. No. 6,513,348 Shetterly et al. which discloses cooling of a formed glass sheet after the forming, all three of which patents are assigned to the assignee of the application and are hereby incorporated by reference. 
       SUMMARY 
       [0004]    An object of the present invention is to provide an improved glass sheet forming system that has versatility in use in performing different glass sheet jobs of different sizes and shapes with reduced downtime so as to provide economy and thus cost reduction of the formed glass product. 
         [0005]    In carrying out the above object, a glass sheet forming system constructed according to the invention includes a pair of glass sheet forming lines extending alongside each other along a direction of conveyance of the forming system. Each of the forming lines includes: a heating furnace for heating glass sheets; a forming location downstream along the direction of conveyance from the furnace which cyclically supplies heated glass sheets to the forming location; and a cooling station located downstream along the direction of conveyance from the forming location to cyclically receive formed glass sheets therefrom for cooling. The forming system also includes three forming stations any two of which can be respectively positioned at the forming locations of the pair of forming lines. Three communication assemblies of the forming system are respectively associated with the three forming stations and each includes: an upwardly extending stanchion having an upper end; a horizontal beam having an elongated length including a distal end having a pivotal connection to its associated forming station; a bearing assembly that mounts the horizontal beam on the upper end of the stanchion for pivotal movement about an associated vertical axis and for horizontal movement along its length; and a looping type wire bundle connected to its associated forming station at the distal end of the horizontal beam and extending therefrom to the stanchion to provide control of the forming station. A control system of the forming system is connected to the wire bundles to operate the pair of forming lines including the heating furnaces, the selected two forming stations respectively in the forming locations, and the cooling stations. 
         [0006]    As disclosed, the forming station includes a pair of storage locations at either of which any one of the forming stations not being used can be stored and at which any two of the forming stations not being used can be stored. 
         [0007]    As also disclosed the upper end of the stanchion of one of the communication assemblies is located higher than the upper ends of the stanchions of the other two communication assemblies so the horizontal beam of the one communication assembly is movable above the horizontal beams of the other two communication assemblies during forming station movement. 
         [0008]    Additionally, the forming station includes a rail assembly having rails and a turntable on which the forming stations are movable within the forming system. The stanchions of two of the communication assemblies are disclosed as respectively located upstream and downstream from the turntable along the direction of conveyance of the forming lines, and the stanchion of the other communication assembly is located adjacent the stanchion of one of those two communication assemblies. More specifically, the stanchions of the two communication assemblies located upstream and downstream from the turntable are aligned with the turntable along the direction of conveyance and the stanchion of the other communication assembly is located laterally relative to the direction of conveyance to one side of the stanchion of one of those two communication assemblies and the upper end thereof is higher than the upper ends of the stanchions of the two communication assemblies so the horizontal beam thereof is movable above the horizontal beams of the two communication assemblies during forming station movement. Also, the pair of storage locations are located upstream and downstream from the turntable along the direction of conveyance of the forming lines to provide for storage of one or two of the forming stations not being used. 
         [0009]    The glass sheet forming system as disclosed has a control system including first and second PLCs (i.e. programming logic controllers) for respectively operating the pair of forming lines, a control panel connected to the associated wire bundle of each forming station to control its operation, and a third PLC for operating the three forming stations through their respective control panels in respective cooperation with the forming lines. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a schematic top plan view of a glass sheet forming system constructed according to the present invention to include a pair of glass sheet forming lines extending alongside each other and also including three forming stations any two of which can be utilized with the two forming lines at any given time, three communication assemblies used in the operation of the forming stations, and a control system that operates the forming lines. 
           [0011]      FIG. 2  is a schematic perspective view of the communication assemblies that operate the forming stations of the forming system 
           [0012]      FIG. 3  is a more detailed perspective view of the communication assemblies. 
           [0013]      FIG. 4  is a somewhat schematic view of one of the communication assemblies shown with a horizontal beam thereof in an extended position connected to the associated forming station at a remote location from an associated stanchion of the assembly. 
           [0014]      FIG. 5  is a view similar to  FIG. 4  but with the horizontal beam in a retracted position extending from the stanchion to the associated forming station at a closer position. 
           [0015]      FIG. 6  is a schematic view taken along the direction of line  6 - 6  in  FIG. 5  to illustrate a bearing assembly on the upper end of the stanchion for supporting the horizontal beam for horizontal and pivotal movement. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. 
         [0017]    With reference to  FIG. 1  of the drawings, a glass sheet forming system embodying the present invention is generally indicated by  10  and includes a pair of glass sheet forming lines  12  extending alongside each other along a direction of conveyance C of the forming system which forms glass sheets G in a cyclical manner. Each forming line  12  includes: a heating furnace  14  for heating glass sheets, a forming location  16  located downstream along the direction of conveyance C from the furnace  14 , and a cooling station  17  located downstream along the direction of conveyance C from the forming location  16  to cyclically receive formed glass sheets therefrom for cooling. It should be noted that the furnace  14  may provide flat glass sheets to the forming location or may include a roll forming end for preforming the glass sheets as disclosed by the previously mentioned U.S. Pat. No. 6,573,484 Bennett et al. which has been incorporated herein by reference, and it should also be mentioned that the cooling station  17  may perform slow cooling for annealing, faster cooling for heat strengthening or rapid cooling for tempering of the formed glass sheets. 
         [0018]    With continuing reference to  FIG. 1 , the glass sheet forming system  10  also includes three forming stations  18  any two of which can be respectively positioned at the forming locations  16  of the pair of forming lines  12 . These forming stations  18  are preferably press bending stations as disclosed by the 6,573,484 Bennett et al. patent which has herein been incorporated by reference. Three communication assemblies  20  of the forming system  10  are respectively associated with the three forming stations  18 . Each of the communication assemblies  20  includes an upwardly extending stanchion  22  which, as shown in  FIG. 3 , has an upper end  24  located above the factory floor  26 . A horizontal beam  28  of each communication assembly  20  has an elongated length including a distal end  30  having a pivotal connection  32  to its associated forming station  18  as shown in  FIGS. 4 and 5 , and each communication assembly  20  also includes a bearing assembly  34  that, as schematically illustrated in  FIGS. 4 and 5 , mounts the horizontal beam  28  on the upper end  24  of the associated stanchion  22  for pivotal movement about an associated vertical axis and for horizontal movement along its length between the extended position shown in  FIG. 4  and the refracted position shown in  FIG. 5 . A looping type wire bundle  36  of each communication assembly  20  is connected to its associated forming station  18  at the distal end  30  of the horizontal beam  28  and has a convention bendable support that limits bending at the bend  38 . At the other horizontal beam end  39 , the wire bundle  36  in its bendable wire support extends around a turn  40  back to the stanchion  22  to provide control of the forming station while still permitting movement of the forming station between different positions in the system closer and farther away from the stanchion. The wire bundles  36  include wires for providing electrical communication and any necessary vacuum or gas pressure tubes for operating the forming station during the glass forming operation. 
         [0019]    With reference back to  FIG. 1 , a control system  42  of the forming system  10  is connected to the wire bundles  36  described above to operate the pair of forming lines  12  including the heating furnaces  14 , the selected two forming stations  18  respectively in the forming locations  16 , and the cooling stations  17 . 
         [0020]    As shown in  FIG. 1 , the glass sheet forming system  10  also includes a pair of storage locations  44  at either of which any one of the forming stations not being used can be stored and at which any two of the forming stations not being used can be stored. 
         [0021]    As illustrated in  FIGS. 2 and 3 , one of the stanchions  22  whose upper end is identified by the reference numeral  24  in  FIG. 2  is higher than the upper ends of the other two stanchions  22  so the horizontal beam  28  of that communication assembly is movable above the horizontal beams  28  of the other two communication assemblies  20  during movement of the forming stations  16 , which allows any two of the forming stations to be positioned in either forming line with the other forming station in one of the storage positions  16  while still having communication through the wire bundles described above to provide operation of the forming stations in both forming lines. It should be mentioned that it is also possible for only one of the forming lines  12  to be operated at any given time with the two other forming stations in the storage locations and located so there is no interference between their communication assemblies  20 . 
         [0022]    The forming station includes a rail assembly  46  having rails  48  and a turntable  50  on which the forming stations are movable within the forming station between the forming locations  16  of the forming lines  12  and the storage locations  44 . Each forming station  18  has power driven wheels  49  ( FIGS. 4 and 5 ) for movement thereof along the rails  48 . 
         [0023]    The stanchions  22  of two of the communication assemblies  20  are respectively located upstream and downstream from the turntable  50  along the direction of conveyance of the forming lines as shown and the stanchion of the other communication assembly is located adjacent the stanchion of one of those two communication assemblies. More specifically, stanchions  22  of the two communication assemblies  20  upstream and downstream from the turntable  50  are aligned along the direction of conveyance C with the turntable  50  and the stanchion  22  of the other communication assembly  20  is located laterally relative to the direction of conveyance C to one side of the stanchion of one of the two communication assemblies aligned with the turntable and the upper end thereof is higher than the upper ends of the other two stanchions such that the horizontal beam of the higher upper ended stanchion is movable above the horizontal beams of the other two communication assemblies during forming station movement to permit the movement to the different positions as described above. This construction permits any two of the forming stations  18  to be respectively used in the two forming lines  12  with communication by the control system for operation. Furthermore, the pair of storage locations  44  are located upstream and downstream from the turntable  50  along the direction of conveyance of the forming lines to provide for storage of one or even two of the forming stations not being used. 
         [0024]    As illustrated in  FIG. 1 , the control system  42  of the forming system  10  includes first and second programmable logic controllers  52  (PLCs) for respectively operating the pair of forming lines  12  and also includes control panels  54  respectively connected to the associated wire bundles of each forming station  18  to control its operation under the control of a third PLC  55  through wire bundles  56  for operating the three forming stations through their respective control panels in respective cooperation with the forming lines. 
         [0025]    As illustrated in  FIG. 6 , the upper end  24  of each stanchion  22  includes a pivotal support  58  that mounts an inverted U shaped frame  60  having lower support rollers  62  that mount the horizontal beam  28  and having upper rollers  64  that provide lateral guiding. Both sets of rollers  62  and  64  can be provided at spaced positions along the length of the horizontal beam so as to facilitate its support and guided movement. 
         [0026]    By the construction of the forming station as described above with the communication assemblies, any two glass sheet forming jobs can be performed while a third forming station has its molds changed in order to reduce the time of job switching from one job to another at one of the forming lines. Thus, scheduling of the glass sheet forming jobs to be conducted timewise can reduce switchover time and thereby reduce the cost of each formed glass sheet produced. 
         [0027]    While an exemplary embodiment is described above, it is not intended that this embodiment describes all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.