Abstract:
A turntable assembled from a plurality of flat sheet metal parts where the sheet metal parts include a series of voids and/or protrusions. The protrusions insert into the voids so that some flat sheet parts are disposed in a vertical orientation and some in a horizontal orientation, the vertical parts substantially perpendicular to the horizontal parts. The flat sheet parts are welded together to create a support structure with the voids and protrusions interacting to align the flat sheet parts within required manufacturing tolerances. One of the horizontally disposed parts has holes therein for attaching the support structure to a hub to create a rotating turntable.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention is related to turntables and a method of manufacture thereof. 
       BACKGROUND OF THE INVENTION 
       [0002]    Rotating devices such as turntables are used in a variety of applications to turn heavy equipment, vehicles, machinery, buildings, seating or other items that are difficult to turn due to weight, space constraints or directional constraints. For example, a rail car engine can be turned on a turntable to quickly re-orient the engine or switch tracks in a rail yard. Turntables may also be used in revolving restaurants, dance floors, stadium seating, auditoriums, homes and other applications where large items need to be rotated or positioned. Rotating devices are often built for the custom needs of each application, whether it be a turntable for positioning manufacturing equipment in a factory or a turntable for positioning rail cars, buildings or other machinery, each application may have different requirements such as size, height and load bearing capacity. 
         [0003]    U.S. Pat. No. 7,631,602 to Schwenker discloses a low profile turntable device having concentric circular and perpendicular lateral band systems for mounting the turntable on a surface. The concentric and perpendicular lateral bands are joined with a clip. The concentric and perpendicular lateral bands generally lie in the same plane and are joined to create a generally two dimensional structure of sheet metal parts. 
         [0004]    U.S. Pat. No. 6,877,437 to Murdock discloses a modular, flexible turntable that is designed to be mounted to an uneven surface. A series of petals extend outwards and are attached to a central disk. The attachment point between the petals and the disc is flexible, and the petals and disc may be fastened together using welding. 
         [0005]    Other versions of turntables are assembled from a series of I-Beam structures that are cut and fit to create a rounded support structure. An example of a prior art turntable is shown in  FIGS. 3 and 4 , and described in detail below. The support structure of the turntable is designed to support the load of the item to be placed on the turntable. Often, the item is heavy and requires a substantial support structure. For example, the item may be a rail car engine. 
         [0006]    The I-Beams and flat metal parts are cut and fit so that the parts can be joined. Often, tolerances associated in forming I-Beams are not acceptable for producing machinery that is designed to move. On the other hand, custom formed I-Beams with tighter tolerances are a prohibitively expensive alternative. Since each part is aligned and welded individually, and the tolerances, straightness and flatness of the beams are not high enough, the fitting and cutting process is extremely labor intensive. The final structure may also have an outer ring formed from a rolled structural member affixed to the outside of the turntable. If the turntable is for rail cars, a track must also be affixed to the turntable, typically directly above the underlying I-Beams of the support structure. 
         [0007]    Prior art turntables also require repeated measurements to check the center and alignment of the pieces of the turntable as the turntable is assembled. Often, these repeated measurements are done by a worker who specializes in welding. A turntable and method of manufacture thereof that make more efficient use of specialized labor is desired to increase efficiency in production. 
         [0008]    There is a need for an improved turntable and manufacturing method thereof that overcomes the disadvantages of the prior art. It is desirable to manufacture a turntable using a method that achieves tolerance requirements with less time devoted to measuring, cutting and fitting. It is further desirable to construct a turntable using a method that requires reduced fitting and alignment skills from workers in order to assemble the turntable. It is further desirable to construct a turntable using a method that allows for reduced lead times during manufacturing. 
       SUMMARY OF THE INVENTION 
       [0009]    An object of the present invention is to provide a turntable and manufacturing method thereof, the turntable assembled from a series of flat metal parts to form a 3-dimensional load bearing structure. 
         [0010]    Another object of the present invention is to provide a turntable and manufacturing method thereof, the turntable having a reduced requirement for skilled labor to cut and fit flat and beam pieces that make up the turntable. 
         [0011]    Another object of the present invention is to provide a turntable and manufacturing method thereof which allows the turntable to be more easily customized than prior art turntables. 
         [0012]    Another object of the present invention is to provide a turntable and manufacturing method thereof that allows for a more efficient use of material in comparison with prior art turntables and manufacturing methods thereof. 
         [0013]    Another object of the present invention is to provide a turntable and manufacturing method thereof, the turntable constructed from sheet metal or metal plate parts having a series of tabs and voids for aligning the parts during assembly and welding. 
         [0014]    Another object of the present invention is to provide a turntable and manufacturing method thereof, where parts making up the turntable may be cut using 2-dimensional cutting tools such as a water jet cutter, laser cutter, or a plasma cutter. 
         [0015]    These and other objects are achieved by providing a turntable having a hub with a plurality of holes therein. The holes are adapted to receive bolts for affixing the hub to a foundation. A support structure attached to the hub, has a plurality of horizontal members with a plurality of voids, and a plurality of vertical members disposed between and substantially perpendicular to, two of the horizontal members. A protrusion extends from an edge of each vertical member, the protrusion is inserted into one of the voids and the vertical members are joined to the horizontal members. 
         [0016]    Further objects are achieved by providing a turntable having a hub with a plurality of holes therein. The holes are adapted to receive bolts for affixing the hub to a foundation. A support structure attached to the hub, has a plurality of horizontal members with a plurality of voids. The voids are disposed in a radial pattern about the horizontal member. A plurality of vertical members are disposed between and substantially perpendicular to, two of the horizontal members. A protrusion extends from an edge of each vertical member, the protrusion is inserted into one of the voids. Each vertical member and each horizontal member is joined along the intersection. 
         [0017]    The voids can extend through the horizontal member, and the horizontal member can have holes for attaching the horizontal member to the hub. A drive mechanism rotates the support structure about the hub, and track is attached to one the horizontal members and the track can be adapted to receive rail cars, maintenance cars, material handling cars and other machinery. The turntable can also have two tracks perpendicular to each other, with a support structure supporting each of the tracks. Further, a side support and side part can be attached to the side of the support structure. The side part is parallel to the horizontal member. 
         [0018]    Yet further objects of the present invention are achieved by providing a method of manufacturing a turntable having the steps of: Providing a hub having a plurality of holes adapted to receive bolts for affixing the hub to a foundation; providing a plurality of vertical members each having an edge with a protrusion; providing a plurality of horizontal members each having a plurality of voids; placing the vertical members substantially perpendicular the horizontal members, such that a protrusion in the vertical member inserts into a void in the horizontal member; welding the vertical members to the horizontal members; and attaching the hub to one the horizontal members. 
         [0019]    The attaching step can include bolts extending through holes in the hub and holes in one of the horizontal members. Another step includes affixing a drive mechanism to the turntable for rotating the turntable. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a top perspective view of an assembled turntable. 
           [0021]      FIG. 2  is a bottom perspective view of the turntable of  FIG. 1 . 
           [0022]      FIG. 3  is a side view of the turntable of  FIG. 1 . 
           [0023]      FIG. 4  is a perspective view of an alternate embodiment of the invention shown in  FIG. 1 . 
           [0024]      FIG. 5   a  is a top perspective view of a prior art turntable. 
           [0025]      FIG. 5   b  is a bottom perspective view of a prior art turntable. 
           [0026]      FIG. 6  is a perspective view of a bottom horizontal member shown in  FIG. 1 . 
           [0027]      FIG. 7  is a perspective view of a partially completed turntable of  FIG. 1 . 
           [0028]      FIG. 8  is a perspective view of a partially completed turntable of  FIG. 1 . 
           [0029]      FIG. 9  is a perspective view of a partially completed turntable of  FIG. 1 . 
           [0030]      FIG. 10  is a detail view of a joint that is found in the turntable of  FIG. 1 . 
           [0031]      FIG. 11  is a perspective view of an alternate embodiment of the invention shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0032]      FIG. 1  is a perspective view of an assembled turntable. A bottom horizontal member  0102  is mounted to a hub (not shown). Lateral vertical members  0104  are affixed between the bottom horizontal member  0102  and a top horizontal member. Longitudinal vertical members  0120  are affixed between the bottom horizontal member  0102  and a top horizontal member. The hub (not shown) is driven by a drive mechanism such as a motor (not shown). Additional drive mechanism options are contemplated such as a hand or machine crank gearing system, levers and the like as would be apparent to one of skill in the art. Rails  0114  are attached above the top horizontal member  0218 (see  FIG. 2 ). The rails  0114 , allow a rail car, locomotive or other railway vehicle to travel on the turntable. A cover  0116  may be placed between the rails to cover gaps for safety purposes. Side supports  0112  may be affixed to the side of the support structure. Side parts  0110  are affixed to the side supports  0112 . The side parts  0110  may be removable to allow for inspection of the drive mechanism or other parts of the turntable assembly. 
         [0033]    Referring to  FIGS. 2 and 3 , a drive mechanism such as a motor  0208  rotates the turntable about a hub  0206 . The side supports  0112  may also include beam members  0216 . These beam members  0216  may be square, rectangle or other cross sections. The beam members  0216  add stiffness and strength to the side support structure and the side parts. 
         [0034]      FIG. 4  shows a perspective view of a partially assembled turntable having two tracks. A continuous vertical member  0404 , vertical arm members  0406  and lateral vertical members  0408  are affixed between a bottom and top horizontal members  0402  and  0418  respectively. Protrusions extend from the edge of the continuous vertical member  0404 , the vertical arm members  0406  and the lateral vertical members  0408 . Each protrusion inserts into a corresponding void of the bottom  0402  and top  0418  horizontal members. The continuous  0404 , arm  0406 , and lateral  0408  members are joined to the bottom  0402  and top  0418  members to create a support structure for a two track turntable. A hub and drive mechanism similar to that of  FIG. 2  is attached to the two track support structure. Further, tracks are attached to the top of the support structure to create a revolving turntable having two tracks. 
         [0035]      FIGS. 5   a  and  5   b  are, respectively, top and bottom perspective views of a prior art turntable manufactured with an old method. The turntable has main beams  0501  that are welded to secondary beams  0503 . The secondary beams are cut and joined to fit the main beams  0501 . Additional plates  0509  may be needed to strengthen the joint. A bent sheet  0505  is attached to the outside of the main beams  0501  and secondary beams  0503  to create a rounded structure. Additional support plates  0507  may be necessary to secure the rounded structure. Additional support plates  0507  must be notched  0511  to attach to secondary beams  0503 . Main beams  0501  and secondary beams  0503  attach to a hub  0515 . The hub  0515  is affixed to a hub (not shown) and a drive mechanism (not shown) rotates the turntable. The hub  0515  must be aligned according to the center of the turntable so that the turntable rotates properly around the axis of the hub. The process of finding center of the turntable is labor and time intensive, thus adding to the cost of the turntable. 
         [0036]      FIG. 6  is a perspective view of a bottom horizontal member shown in  FIG. 1 . The horizontal member  0102  has a plurality of holes  0604  for securing the horizontal member to a hub (not shown). The holes  0604  are already cut to receive a hub, and it is therefore not necessary to measure the center of the turntable during assembly. The center is already built into the horizontal member  0102  and the holes  0604 . The horizontal member  0102  also has a series of voids  0602  for receiving tabs (not shown) from vertical members (not shown). The voids  0602  are also designed relative to center to ensure that the turntable, once assembled will rotate within tolerance requirements, with a reduced need to check and re-check center measurements during assembly. 
         [0037]      FIG. 7  is a perspective view of a partially completed turntable of  FIG. 1 . Lateral vertical members  0706  have top tabs  0712  that insert into voids in a horizontal member  0102 . Lateral vertical members  0706  also have side tabs  0714 . Side tabs  0714  insert into voids in longitudinal members  0702 . Longitudinal members  0702  have rail support voids  0710  for receiving a tab from a rail support member (not shown). 
         [0038]      FIG. 8  is a perspective view of a partially completed turntable of  FIG. 1 . A top horizontal member  0218  is placed on top of the longitudinal and lateral vertical members. Voids  0808  in the top horizontal member  0218  receive tabs from web members. 
         [0039]      FIG. 9  is a perspective view of a partially completed turntable of  FIG. 1 . The figure shows the support structure  0900  of the turntable without rails or side parts. Rail channels  0902  are affixed to the top horizontal member  0218 . Inner and outer rail supports  0906  and  0904  respectively are affixed to the longitudinal web member  0702   
         [0040]      FIG. 10  shows a tab  1002  inserted into a void  1004 . Weld  1006  joins the vertical member  0702  to horizontal members  0102  and  0218 . Weld  1008  and  1010  join the rail support  0904  to the web  0702  and the horizontal members  0102  and  0218 . 
         [0041]      FIG. 11  shows a bottom horizontal member  1102  having voids  1106  disposed in a radial pattern to receive protrusions  1110  of a plurality of vertical radial members  1104 . Holes  1108  in the bottom horizontal member  1102  attach to a hub similar to the hub shown in previous figures. A top horizontal member (not shown) is located on top of the vertical radial members  1104 , with protrusions  1112  extending into voids disposed in a radial pattern corresponding to the radial pattern of the bottom horizontal member  1102 . 
         [0042]    Although some of the drawings have shown a turntable having tracks, the turntable may be designed to rotate or position items other than railway vehicles and the turntable may be designed with no tracks. Other vehicles include material handling carts, repair cars, moveable machinery and the like as would be apparent to one of skill in the art. 
         [0043]    Furthermore, the invention has been shown with horizontal members having voids and vertical members having protrusions. It is contemplated as within the scope of the invention that the horizontal member could have protrusions and the vertical members could have voids. Additionally, a horizontal or vertical member may have both voids and protrusions. 
         [0044]    In the example of a turntable with no tracks the turntable may be designed to rotate a building structure, a vehicle or machinery on a factory floor. Additional vehicles, structures, machinery and the like are contemplated within the scope of the invention as would be apparent to one of skill in the art. 
         [0045]    Although the invention has been described with reference to a particular arrangement of parts, features and the like, these are not intended to exhaust all possible arrangements or features, and indeed many modifications and variations will be ascertainable to those of skill in the art.