Abstract:
A modular tower assembly for use with blown film extrusion processes, where modular tower sections each having identical columns/foot prints can be stacked on top of one another. Each module can have rectangular type platforms with walk decks about a central rectangular void middle. Staircases can be built into the side of all decks modules up to the top deck. Each of the four vertical legs of the deck modules has flat plate bottoms to stack on the deck surface of the module beneath, and side cross bracing. Side extension platform deck wings with legs can be used when the central rectangular void is enlarged. The modules can be pre-formed and brought onsite to be erected in a rapid assembly manner by fasteners such as bolts, and be removable as compared to permanent type welded towers. The modular towers can include adjustable bracing components for further stiffening the modular towers to have reduced swaying, twisting and vibrations over time.

Description:
[0001]    This invention relates to towers, and in particular to a modular tower and a method of assembling the modular tower useful for different processes such as blown film processes having modular tower sections, each section having the same columns/foot prints for facilitating pre-wiring and pre-piping that can be stacked on top of one another, along with novel bracing, and which claims the benefit of U.S. Provisional application 60/254,273 filed Dec. 8, 2000.  
         BACKGROUND AND PRIOR ART  
         [0002]    The blown film extrusion process is a vertically oriented extrusion process that requires a structure, commonly called a “blown film tower” to host equipment at different elevations and provide physical space to enhance film cooling. The blown film process is a well known type of thermoplastic extrusion process where raw materials such as pellets of solid polyethylene are placed into and gravity fed through a hopper. A feed screw and electric type heater component inside a barrel beneath the hopper further mushes and melts the pellets. A resulting uniform homogenous melted material (having the consistency of a jello type material) is then fed through a coloring dye into the bottom of a blown film tower, where a compressed air supply injects air into a holder forming a film bubble. The resulting bubble rises upward through the middle of the tower to a shaping device such as a hollow funnel adjacent to the top of the tower having a narrow upper opening where a conventional nip and roll assembly on top of the tower allows for resulting film to be pulled out.  
           [0003]    Conventional blown film towers are usually custom made for each worksite to specific heights and dimensions. These towers include many raw steel type materials and extensive labor installation time for assembly. Generally, the components of these conventional towers are permanently welded in place. Installing these towers can take up to 45 days or more to assemble and cost up to and over some $400,000 to complete. U.S. Pat. No. 3,980,418 to Schott, Jr.; U.S. Pat. No. 4,243,363 to Mulcahy; U.S. Pat. No. 4,355,966 to Sweeney et al. and U.S. Pat. No. 4,402,656 to Schott, Jr., each show blown film processing systems that use conventional type towers having the types of problems previously described.  
           [0004]    Other Patents exist on scaffolding type systems and stair case units that also fail to overcome problems described above. These patents include U.S. Pat. No. 3,752,262 to Helms; U.S. Pat. No. 3,768,016 to Townsend et al.; U.S. Pat. No. 3,807,120 to Viandon; U.S. Pat. No. 3,817,347 to Spencer; U.S. Pat. No. 4,867,274 to Langer; U.S. Pat. No. 5,135,077 to Shalders and U.S. Pat. No. 5,491,939 to Wang.  
         SUMMARY OF THE INVENTION  
         [0005]    The primary objective of this invention is to provide a modular blown film tower that is customizable for different features. Auxiliary components such as cooling coils, blenders, and the like can be added onto the tower. Floor elevation, stair placement can be adjusted, and additional mezzanine extensions and deck areas can also be expanded or contracted.  
           [0006]    The second objective of this invention is to provide a modular blow film tower that is easily changeable. The tower can be reconfigured for a different setup and/or dismantled and moved for relocation purposes.  
           [0007]    The third objective of this invention is to provide a modular blow film tower that is quick and simple to install. The novel tower can arrive onsite in a prefabricated kit form that can be fastened together with bolts, and the like, in approximately one to five days (usually encompassing no more than approximately 8 to approximately 30 hours). The bolt type fastened construction minimizes disruptions to existing facilities, and can be planned for installation on the user&#39;s desired schedule.  
           [0008]    The fourth objective of this invention is to provide a modular blow film tower that made for the selected worksite. The modular tower would be adaptable and is not isolated from other different existing towers that can exist onsite, since the modular tower allows for width, depth, and elevation adaptability to almost all types of plants. Using two modular towers allows for common servicing for each film line in a plant.  
           [0009]    The fifth objective of this invention is to provide a modular blow film tower that allows the ability of the blown film processing user to be able to refit their lines in place. This ability allows the user to easily expand a line widths and/or elevations as their few process opportunities demand changes.  
           [0010]    The sixth objective of this invention is to provide a modular tower for processes such as blown film processes that allows the user to use identical column footprints for different levels.  
           [0011]    The seventh objective of this invention is to provide a modular tower having adjustable braces such as cross-braces, for stiffening the tower and for reducing swaying and twisting of the tower along with reduced vibrations, when plural platforms are stacked on top of one another.  
           [0012]    The eighth objective of this invention is tp provide a modular tower having adjustable braces such as cross-braces, for stiffening the tower and for reducing swaying and twisting of the tower along with reduced vibrations, when heavy equipment is placed on the tower.  
           [0013]    The ninth objective of this invention is to provide a modular tower having adjustable braces such as cross-braces, for stiffening the tower and for reducing swaying and twisting of the tower along with reduced vibrations, when equipment such as machinery is running on the tower.  
           [0014]    The tenth objective of this invention is to provide a modular tower that can use the same backfill (support member) for different sized nip components (i.e. different widths, lengths, etc.), without having to customize a separate backfill and/or separate tower structure for each different sized nip component.  
           [0015]    The preferred embodiment of the invention includes a modular multi-level blown film tower that can be fastened together by bolts. The modular tower allows for concurrent erection of the elevated equipment necessary for blown film processing along with the tower itself. This method vastly reduces time and cost of blown film equipment installation. The novel fixed position of the tower columns and known platform area simplifies and eases the electrical wiring and water and air piping of the equipment routed through the tower again reducing time and costs. The modular components for the tower can include core platform segments, handrails, columns, stairs and backfill. Various extensions can be utilized for expanding the platform area for accommodating nip assembly and additional equipment width variability. Easy expansion or contraction optimizes platform areas for tower mounted equipment. Each additional extension level can also consist of platform segments, handrails, columns, stairs and backfill. The stackable assembly method allows for concurrent equipment and platform lifting. This is done by attaching the film equipment to its respective platform at floor level then raising both the platform and the equipment together adding subsequent levels of combinations of equipment and platforms. The stackable assembly method eliminates having to open up a roof of a building in order to place equipment on a previously established tower.  
           [0016]    Columns supporting each of the platform levels above the floor are dimensionally fixed despite the width of the nip roll and collapsing assembly. When nip assembly widths encroach on the outer limits of the structure thus eliminating operator access in the cross direction, extensions can be added. Conversely, narrow nip assemblies can be hosted by backfilling the opening with a separate metal (such as steel) insert on the available inside area. The pre-positioned fixed columns and platform dimensions allow for pre-calculated paths for servicing the tower hosted equipment with required wires, air and water pipes/ducts. This advance planning capability is key to reducing equipment installation time and cost. Since buildings using blown film processing varies as to size and dimensions, the modular tower invention allows for variable height levels as needed in order to conform to the available installation space and/or to match the size and dimensions of existing structures.  
           [0017]    Adjustable bracing such as cross-bracing having threaded bars, and the like, can be attached to tower legs and to cross members to aid in stiffening the tower when heavy equipment is positioned on the tower, machinery is running on the tower and/or when plural platforms are stacked on top of one another. The adjustable bracing can square off, center, and align the tower. Furthermore, the towers can have reduced swaying, twisting and vibrations over time.  
           [0018]    Further objects and advantages of this invention will be apparent from the following detailed description of a presently preferred embodiment which is illustrated schematically in the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0019]    [0019]FIG. 1 is an exploded perspective view of a first preferred embodiment of the modular tower assembly.  
         [0020]    [0020]FIG. 2A is a perspective view of FIG. 1 with the modular tower assembly attached together.  
         [0021]    [0021]FIG. 2B is a side view of the FIG. 2A along arrow A without stairs.  
         [0022]    [0022]FIG. 3 is an exploded perspective view of FIG. 1 with a Nip component and backfill support.  
         [0023]    [0023]FIG. 4 is a view of the nip component and backfill support being raised inside of a building.  
         [0024]    [0024]FIG. 5 is a view of the nip component, backfill support, and first platform being raised above a second platform being readied.  
         [0025]    [0025]FIG. 6 is an assembled view of FIGS. 4 and 5 with two platforms.  
         [0026]    [0026]FIG. 7A is a perspective view of a second embodiment of a three platform modular tower.  
         [0027]    [0027]FIG. 7B is a side view of the second embodiment of FIG. 7A along arrow B.  
         [0028]    [0028]FIG. 8 is a perspective view of a third embodiment of plural modular towers of the first embodiment attached side-by-side to one another.  
         [0029]    [0029]FIG. 9 is a side view of a fourth embodiment lifting both a nip assembly and a platform assembly concurrently.  
         [0030]    [0030]FIG. 10 shows a fifth embodiment of using hooks inside of a building for lifting tower components.  
         [0031]    [0031]FIG. 11 shows a sixth embodiment of using adjustable braces for stiffening tower components. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0032]    Before explaining the disclosed embodiments of the present invention in detail it is to be understood that the invention is not limited in its application to the details of the particular arrangement shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.  
         [0033]    First Embodiment  
         [0034]    [0034]FIG. 1 is an exploded perspective view of a first preferred embodiment 1 of the modular tower assembly. FIG. 2A is a perspective view of FIG. 1 with the modular tower assembly attached together. FIG. 2B is a side view of the FIG. 2A along arrow A without stairs.  
         [0035]    Referring to FIGS. 1, 2A and  2 B tower assembly  1  includes a top platform  100  having four column legs  110 ,  120 ,  130 ,  140  having upper ends  114 ,  124 ,  134 ,  144  attached to an underside portion of the frame  190  of the platform  100 , and lower flat feet portions  112 ,  122 ,  132 ,  142 . Cross-bracing members  113 ,  115 ,  117 ,  123 ,  125 ,  127 ,  133 ,  135 ,  137 ,  143 ,  145 ,  147  form triangular structures attached between columns  110 - 140  and deck frame  190 . About the deck frame  190  can be four hand rail sections  150 ,  160 ,  170  and  180  that can also be similarly fastened thereto as the column legs  110 - 140 . A shortened handrail section  152  has an opening for allowing a stairway (not shown here) to be accessed. The decking platform  190  has walkway portions  192 ,  194 ,  196 ,  198  for allowing workers to move about and access the nip assembly (shown and described later in reference to FIGS.  3 - 6 ). A void  199  in deck  190  is used as the bubble void area previously described in the background section of the application.  
         [0036]    A lower platform  200  has similar components to the upper platform  100 . Lower platform  200  can include column legs  210 ,  220 ,  230 ,  240  each with flat feet ends  212 ,  222 ,  232 ,  242 , respectively, and cross-bracing members forming triangular portions between the columns. On the top of deck  290  are upper column ends  211 ,  221 ,  232 ,  241  which have the same locations as feet portions  112 ,  122 ,  132 ,  142 , respectively, so that the columns can be attached to one another in the same locations. Side handrails  250 ,  280 ,  270  surround the perimeter of decking platform  290 . Here, a corner handrail  260  can stick from the deck platform  290  for allowing a stairway  205  to be attached thereto. Walkway portions  292 ,  294 ,  296 ,  298  are similar to those described in reference to upper platform  100 .  
         [0037]    An optional side platform extension  400  can be attached to side of the deck platform  290 . Side platform can have a solid deck platform  490  with two column legs  410 ,  420  each with respective lower flat feet portions  412 ,  422  that allow the platform to be supported at ground level or on top of another side platform if an additional platform level is below platform  200 . Cross braces  415 ,  425  support the column legs  410 ,  420  and side handrails  450 ,  460 ,  470  similarly to those described for platforms  100 ,  200  can also be used. Side or rear platforms  400  can be used for supporting more equipment thereon, and or workers, and the like. The side/rear extension platforms can also be used for the upper platforms  100  when larger equipment (such as but not limited to large nip assembly components (shown and described in reference to FIGS.  3 - 5 ) are used. The side/rear extensions  400  optimize the platform areas and walkway areas for tower mounted equipment. Each side/rear extension can also include separate stairways as needed.  
         [0038]    The platforms  100 ,  200 ,  400  can be made from metal such as but not limited to steel, and the like, where substantially all of the components can be fastened together by bolts, and the like. A working version of the two level embodiment 1 can have a general load bearing of approximately 75 pounds per square foot, with point loading (at center of tower) able to support approximately 1000 pounds. The lower second level  200  can be approximately 8 to approximately 12 feet high from ground level, with the top first level  100  approximately 10 feet higher than the lower level  200 . The overall height of the two level tower top deck  190  can between approximately 18 and approximately 22 feet above ground level.  
         [0039]    [0039]FIG. 3 is an exploded perspective view of FIG. 1 with a Nip component assembly  25  supported thereon by a backfill support member  50 , such as a steel plate, and the like. The novel stackable nature of the invention allows for concurrent equipment and platform lifting. The novel modular towers can be constructed in pre-existing buildings  10  without having to remove the entire or substantial portions of the roof  12 . In this example, a small opening  15  can be used in the roof  12  large enough to allow a line  77  from an exterior located crane  80  to be inserted therethrough. The line can be connected to a crane type hook  75  which can be attached to cradle type lines  70  which can be attached to the backfill support member  50  which supports the nip assemblies  25  used in blown film processing applications such as those previously described in the background section of the invention.  
         [0040]    [0040]FIG. 4 is a view of the nip component  25  and backfill support  50  being raised inside of a building  10 , from floor level  14  in the direction of arrow R 1 . As the backfill and nip components  25  are in a raised position, the top platform deck  190  with handrails  150 ,  160 ,  170 ,  180  can be assembled on the floor level  14 . Thus, the space below the raised backfill  50  and nip components  25  can become a staging center for the platforms. After platform  190  with handrails  150 - 180  is assembled, the backfill support  50  with nip component  25  can be lowered down in the direction of arrow R 2  onto the platform  190  and attached thereto as needed. Next the cradle type lines  70  can be reattached to the platform  190 . Alternatively, while the backfill support  50  and nip component  25  are in a raised position of R 1 , the upper platform  190  and it&#39;s associated components such as handrails  150 - 180  along with columns  110 - 140  can be erected on floor level  14 .  
         [0041]    [0041]FIG. 5 is a view of the nip component  25 , backfill support  50 , and first platform  100  being raised above while a second platform components  290 , and associated handrails are being readied. In FIG. 5, the cradle lines  70  are attached to upper platform  100  which already has handrails, stairway  105  and vertical column legs  110 - 140  attached thereto, and are raised above floor level  14  in the direction of arrow R 3 . When either deck platform  290  and associated handrails or deck platform  290  and associated handrails and its&#39; respective column legs  210 - 240  are attached, the upper deck  100  is lowered in the direction of arrow R 4 , with the respective lower flat feet ends  112 ,  122 ,  132 ,  142  (shown more clearly in FIGS.  1 - 2 ) are positioned in the identical column foot prints  211 ,  221 ,  231 ,  241  of lower platform  200 . Referring to FIG. 5 additional modular extension  500  having a deck platform portion  590  and side handrails  550  with or without column legs, can be attached to the side of upper platform  100  as needed. When either modular extension  500  or side/rear extension platforms  400  (previously shown and described) are used, adjacent handrails on the platform  100  can be removed when needed. Auxiliary components (not shown) used in blown film processing techniques such as but not limited to cooling coils, blenders, and the like can be added onto the tower. FIG. 6 is an assembled view of FIGS. 4 and 5 with two platforms  100  and  200  in place.  
         [0042]    Second Embodiment  
         [0043]    [0043]FIG. 7A is a perspective view of a second embodiment  301  of a three platform modular tower with three platforms  100 ,  200 ,  300 . FIG. 7B is a side view of the second embodiment of FIG. 7A along arrow B. Referring to FIGS. 6, 7A, and  7 B, a third platform  300  with or without column legs can be readied while the platforms  100  and  200  are being in a raised position similar to when platforms  100  and  200  were being erected. Similar to the first embodiment, three and more platforms can be assembled with this invention all having fixed columns and feet ends. The three level embodiment of FIGS.  7 A- 7 B can have the upper top deck  100  approximately 28 to approximately 32 feet above ground level.  
         [0044]    Third Embodiment  
         [0045]    [0045]FIG. 8 is a perspective view of a third embodiment  1000  of plural modular towers  1 ,  1 ′, and  1 ″ of the first embodiment 1 attached side-by-side to one another. Additional towers can be attached side by side to form four or more towers in a row. Additionally, the novel towers can be placed in together in different formations to form different layout orientation configurations, such as an L-shape, a T-shape an X shape configuration, rectangular configuration, and the like. Additionally, a ground level platform can be larger than the upper stacked platforms so that matched footprints are one the upper platforms only. Thus, a lower platform can have greater expanded spread apart foot prints for their vertical columns (legs) than the footprints of the columns on the upper stacked platforms. Furthermore, various combinations of different spaced apart footprints for different platforms can be used together in different combinations.  
         [0046]    Fourth Embodiment  
         [0047]    [0047]FIG. 9 is a side view of a fourth embodiment of lifting components concurrently to build the modular tower such as lifting both a nip assembly  25 / 50  and a platform assembly  100  concurrently. The concurrent lifting can allow both a backfill  50  and nip components  25  to be pre-placed on a platform deck  190  with or without the vertical legs beneath the platform deck, and lifted by lines  70  connected to hook  75  which is attached to line  77  which passes through an opening  15  in the roof  12  of a building  10 . Likewise, other concurrent lifting can allow both nip assembly  25 / 50  with an entire platform assembly  100  to be lifted concurrently. This concurrent lifting capability can be used with any of the proceeding embodiments disclosed.  
         [0048]    In some old techniques, it was possible to directly attach a nip component to a platform deck without using a separate and isolated backfill (support member), and then lift the deck and nip component upward. However, this old technique had problems of requiring a nip component to be permanently attached to the deck, which has required some customization and additional cost and expense.  
         [0049]    With the subject invention, a concurrent lift can be accomplished. Here, a nip component with backfill can be placed on a deck and then lifted upward. The backfill can remain separate and isolated from the deck, and the nip does not have to be permanently mounted to the deck itself. Thus, no permanent attachment is necessary and no customization would be required, and reduced costs and expenses will result during the construction of the towers.  
         [0050]    In conventional center rig type techniques, a nip component has been known to be able to be lifted upward through a center opening of a tower by center type rigging. After the nip assembly is lifted up, an artificial backfill must be separately created and formed on top of the platform after the nip component has been raised, which often results in customizing backfills (support members) every time a tower is constructed. Additionally, it should be noted that these artificially created backfills have to be created on top of large height towers which is an additional problem as to cost and expense.  
         [0051]    In the subject invention, a backfill (support member) is not created on top of the tower. Here, a nip component is set onto a pre-created backfill (support member) on ground level. Then both the nip component and the backfill can be raised up through the middle opening in the tower by using a center rigging on top of the tower, and then positioned on the top deck of the tower using methods previously described above. Thus, workers do not have the extra time and expense of creating a customized backfill on top of the tower.  
         [0052]    The subject invention allows for different sized nip components (i.e. larger, smaller, wider, narrower, etc.) to be placed on the tower without having to customize a separate backfill (support member) and/or customize a separate tower structure every time a different sized nip component is being used. In the subject invention, the same backfill (support member) can be used for different sized nip components without having to change the size and dimensions of the backfill (support member).  
         [0053]    Fifth Embodiment  
         [0054]    [0054]FIG. 10 shows a fifth embodiment  3000  of using lifting members such  3100  such as hooks, and block and tackle components, and pulleys inside of a building for lifting tower components, instead of having an opening through the roof  12  as disclosed in previous embodiments. For example, a hook  3100  can be attached to an interior ceiling under a roof  12  within a building, and lines  77  can lift tower components such as the nip assembly  25 / 50 , platform assembly  100 , and any other tower components. Additionally, the lifting members can be placed on pre-erected towers, rigging on the towers, and the like, within a building so that a tower can be constructed within and/or underneath an existing tower. Additionally, other lifting techniques can include forklifts, cranes, and the like, to lift and lower tower components during assembly.  
         [0055]    Sixth Embodiment  
         [0056]    [0056]FIG. 11 shows a sixth embodiment  3500  of using adjustable braces for stiffening tower components. Referring to FIG. 11, a tower components such as a deck  3550  can be supported by vertical legs  3610  and  3620  which correspond to the tower components previously described. In this embodiment a horizontal cross member  3630  can be connected and attached to pairs of vertical legs  3610 ,  3620  by fastening plates  3650  by removable fasteners such as bolts, screws, and the like. Alternatively, the connections can be done by welding and the like. Midway along horizontal cross member  3630  can be centrally located fastening plate  3750  having connectors  3730 ,  3830  such as threaded rod connectors protruding at upwardly directed angles to the respective vertical legs  3610 ,  3620 . Adjustable braces  3720 ,  3820  such as threaded rods, can have one end inserted to and attached to the threaded connectors  3730 ,  3830 , and opposite ends threadably attached to lengthening adjustment members  3710 ,  3810  such as but not limited to turn buckle type adjustment members, that are attached to upper side portions of the vertical legs  3610 ,  3620 . Tightening the lengthening members  3710 ,  3810  such as rotating the turn buckles, can result in stiffening the tower components which can include keeping the vertical legs  3610 ,  3620  from swaying, twisting and vibrating that can occur to the tower(s). For example, a single platform assembly can be stiffened as needed to take care of situations when extra weight loads are placed on the towers, machinery is running on the towers, and the like. Multiple level stacked towers can also benefit by having these stiffening adjustment capability to additionally reduce any swaying, twisting and vibration effects that can occur over time.  
         [0057]    Although the preferred lengthening adjustment members are described as threaded rods, other types of-adjustment members can be used such as adjustable length cables, and the like. Furthermore, other the stiffening members can be placed on other locations of the tower such as beneath horizontal cross members, and as tie downs from the tower to ground connected ends, and the like.  
         [0058]    Although the preferred embodiment is described using steel members that are generally bolted together, other types of materials such as but not limited to aluminum, fiberglass, hardened plastic, and the like, and other fasteners such as screws, clamps, and the like, can also be used, to form the modular novel towers of the subject invention.  
         [0059]    While the preferred embodiments show up to three deck platform levels, the invention can be practiced with more levels as needed.  
         [0060]    Although each of the subject invention embodiments is separately described, each of the embodiments can be used with each other in and in various combinations together.  
         [0061]    Although the preferred embodiments are described for use in blown film processing, the invention can be used in other applications, both indoor a building and outside of a building. For example, other applications of the novel modular towers, such as but not limited to communication towers, and the like, can be erected using the novel invention embodiments.  
         [0062]    While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications which it has presumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.