Abstract:
A multi-directional scaffold transport device, which may be attached to each base of a scaffold&#39;s legs, provides increased mobility in relation to movement atop corrugated floor decking with vertical anchor studs used in conventional steel I-beam superstructures. The device comprises an elongated flat plate with angled extensions. The angled extensions may form a trapezoidal shape, or more preferably a triangular shape, and may be curved or have compound curvature to enable deflection of the device to either side of any anchor stud encountered, rather than jamming thereon. The elongated flat plate may have minimal length sufficient to normally receive support from at least two peaks of the corrugated decking. The device may incorporate threaded studs protruding from the elongated flat plate, which may be received by holes in the base of the scaffold, and be removeably fastened thereto using nuts. The device may also incorporate vertical walls for increased stiffness.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to improvements in construction devices and methods, and more particularly to devices and methods that improve the functionality of scaffolding typically used in construction and remodeling. 
       BACKGROUND OF THE INVENTION 
       [0002]    Scaffolding has many uses, particularly for the construction and maintenance of buildings. A scaffold assembly can be used as a single tier, but is usually formed to allow stacking of the scaffold assembly so that many tiers may be joined to provide workers with the ability to reach great heights above the ground or above a particular floor in a building. Very often, the tiers of a scaffold may be so high that they must be tied to a building to prevent accidents. Several tiers of scaffolding being so stacked can become unstable, which may be exacerbated by the movements of the workers, by high winds, and by other natural and man-made factors. 
         [0003]    But when scaffolds are used during the construction process within a building utilizing steel I-beam construction, stability does not generally pose a serious problem, and instead, mobility is a factor to be considered. The mobility of the scaffold may adversely impact productivity, even where the scaffold assembly might only be one or two tiers high, while working on an individual floor of a modern building. The scaffolding would therefore not need to be tied to a wall, and conversely may need to be constantly relocated to various positions throughout the building&#39;s floor. 
         [0004]    The worker&#39;s productivity may be limited by mobility, due to the methodology utilized in steel I-beam construction. The initial phase of construction for the building often involves the substructure, in which piles may be driven down to reach bedrock, alternatively, shafts may be drilled, into which steel reinforcing rods are inserted, and the shafts are then filled with concrete. A foundation platform consisting of reinforced concrete is then poured above the support columns. Rising up from the foundation platform is the superstructure. A common method of forming the building&#39;s superstructure for modern office buildings and skyscrapers involves erecting steel I-beam columns, to which are attached steel girders and cross-beams that form a steel skeleton. 
         [0005]    Steel Decking is then attached to the horizontal I-beams, usually being welded in place. The decking typically consists of panels of thin corrugated steel. An early example of the steel decking that may be used is illustrated in  FIG. 5  of U.S. Pat. No. 757,519 to Turnbull, which has “cylindric corrugations.” A later example is shown by U.S. Pat. No. 4,453,364 to Ting which generally has flat surfaces- peaks, valleys, and sloping webs that form trapezoidal corrugations. 
         [0006]    It has been known for some time, in the art of construction, to attach anchor studs to steel I-beams to serve as a shear transfer element, which is shown by U.S. Pat. No. 2,987,855 to Singleton. Singleton also shows use of steel decking that has wave-like corrugations, and which appear more sinusoidal than cylindric. It is also quite common to weld steel anchor studs to the decking at the I-beam locations, with one such approach being shown by U.S. Pat. No. 3,363,379 to Curran. Generally, at some optimum point in the construction sequence thereafter, concrete is poured over the corrugated decking and anchor studs to establish the particular floor of the building. However, before the concrete is actually poured, and after the decking and the studs have been secured to provide a stable platform, many other steps are performed to facilitate the overall construction of each floor, including installation of diagonal side bracing, which requires use of scaffolding. 
         [0007]    At this point in the construction, the scaffolding must be placed atop the steel decking in a manner that makes it stable, despite only having periodic support from the corrugations. It is not uncommon to bolt the base plates of the scaffold shown in  FIG. 7 , to a series of wood planks which may form a rectangular base. But the scaffold then must be lifted and carried from position to position about the decking, which might require removal of the wood planks in order to reduce the weight of the scaffold assembly being transported. 
         [0008]    The multi-directional transport device disclosed herein may be attached to each base of a typical scaffold, to provide a more efficient means of relocating the scaffolding about the decking without use of wood planking, and without the need to lift and carry the assembly, possibly eliminating the need for the assistance of a second worker. 
       OBJECTS OF THE INVENTION 
       [0009]    It is an object of the invention to provide a means for supporting a scaffold assembly on the corrugated steel decking of a building&#39;s I-beam superstructure. 
         [0010]    It is also an object of the invention to provide a means of stabilizing a scaffold assembly when being utilized atop the corrugated steel decking of a building&#39;s I-beam superstructure. 
         [0011]    It is another object of the invention to provide a scaffold support device that can remain affixed to the scaffold during its transportation. 
         [0012]    It is a further object of the invention to provide a device which may increase the mobility of a scaffold assembly while being utilized atop the corrugated steel decking of a building&#39;s I-beam superstructure. 
         [0013]    It is another object of the invention to provide a device which may be attached to the base of a scaffold assembly and permit the scaffold to slide across the corrugations of the steel decking of a buildings sub-floor. 
       SUMMARY OF THE INVENTION 
       [0014]    The present invention is directed to providing improved mobility to a typical scaffold assembly being utilized in the maintenance of buildings or at building construction sites. A conventional scaffold assembly is shown in  FIG. 7 , and typically has a plurality of legs to provide support, which usually terminate in a flat base in order to provide stability. Where the scaffold is principally utilized in a single location for a substantial period of time, scaffold mobility is not a significant factor. However, where scaffolding is utilized on individual floors of a new multi-story building, mobility may be an important factor, as it may affect productivity. This is especially true where the building is constructed using a standard I-beam superstructure with corrugated floor decking having vertical anchor studs. 
         [0015]    To facilitate increased mobility of a construction scaffold in that scenario, and thereby increase productivity, the multi-directional scaffold device herein disclosed may be attached to the scaffold&#39;s legs. The device comprises an elongated flat plate with an angled extension at respective ends of the flat plate. The length of the elongated flat plate may be chosen to always obtain support from at least two peaks of the corrugated steel decking. The angled extensions may be have a trapezoidal shape, or may alternatively have a triangular shape. The angled extensions may also be flat, or they may alternatively curve upwards. They may additionally have curvature in two directions, resulting in a compound curved surface. These variations for the angled extensions may be incorporated to provide a means of having tangential contact of the multi-directional transport device with the anchor studs of the floor deck, and thereby greatly reduce the possibility of jamming on an anchor stud due to direct contact from a flat surface, which would impede ease of scaffold movement by a single worker. 
         [0016]    The multi-directional scaffold device may have vertical walls incorporated into it to provide stiffness, which may be necessary where the scaffold being supported will be very heavy. These walls may comprise integral stiffeners, or may alternatively be separate flanges which are welded to the elongated flat plate and angled extensions. The stiffeners may also be in the form of other geometric shapes, such as an angle, which may be fastened, rather than welded, to the elongated flat plate and angled extensions. 
         [0017]    To facilitate attachment of the multi-directional transport device to the scaffold, the device may incorporate threaded studs that protrude vertically from the top of the elongated flat plate. Holes may be drilled in the flat base of the scaffold legs to receive the studs, and nuts may then be threaded onto the studs to removeably attach the device to the scaffold. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a top view and side view of a first embodiment of the multi-directional scaffold transport device. 
           [0019]      FIG. 2  is a top view, side view, and section cut through a second embodiment of the multi-directional scaffold transport device, shown with threaded studs. 
           [0020]      FIG. 3  is a top view, side view, and section cut through a third embodiment of the multi-directional scaffold transport device. 
           [0021]      FIG. 4  is a top view and side view of a fourth embodiment of the multi-directional scaffold transport device. 
           [0022]      FIG. 5  is a top view and side view of a fifth embodiment of the multi-directional scaffold transport device. 
           [0023]      FIG. 6  is a top view and side view of a sixth embodiment of the multi-directional scaffold transport device. 
           [0024]      FIG. 7  is a perspective view of a typical construction scaffold. 
           [0025]      FIG. 8  is a section view of the second embodiment of the multi-directional scaffold transport device, shown attached to the base of a construction scaffold, and sitting atop the corrugated steel decking of a building&#39;s superstructure. 
           [0026]      FIG. 9  is an exploded view of a modified leg and base of a scaffold. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]      FIG. 1  shows a first embodiment of the multi-directional scaffold transport device  20  of the present invention. The multi-directional scaffold transport device  20  may be constructed of any appropriate material, including, but not limited to, aluminum, steel, titanium, brass, phenolic, plastic, or wood. The multi-directional scaffold transport device  20  may be formed from sheet metal comprised of multiple bends, or it may be an assembly of parts fastened or welded together, or it may be a casting, or a machined part. The method of manufacture and the material utilized to produce the device may be determined by the manufacturer, and may be specially selected to suit the particular scaffolding and building site. 
         [0028]    The multi-directional scaffold transport device  20  in  FIG. 1  may be comprised of an elongated flat plate  21 , which may be defined as having a top surface  22 , a bottom surface  23 , a first end  24 , a second end  25 , a first side  26 , and a second side  27 . In a preferred embodiment the first end  24  and second end  25  are generally parallel to each other, and first side  26  and second side  27  are also generally parallel to each other, to generally form a rectangular-shaped plate. The length of the first side  26  and second side  27  are approximately equal, and each of which may be several times longer than the length of first end  24  and second end  25 , which themselves are approximately equal to each other in length. 
         [0029]    Extending from first end  24  may be a first angled extension plate  30 . First angled extension plate  30  may be integral to first end  24  of elongated flat plate  21 , and thus may simply be a bent up sheet metal flange extending therefrom, or alternatively it may be mechanically fastened onto or welded to first end  24  of elongated flat plate  21 . A second angled extension plate  40  may extend from second end  25  just the same as is herein described for first angled extension plate  30  extending from first end  24 . 
         [0030]    First angled extension plate  30  may be described as having a top  31 , a bottom  32 , a fixed end  33 , an elevated end  34 , a first tapered side  35 , and a second tapered side  36 . In a preferred embodiment, first tapered side  35  and second tapered side  36  both angle towards each other, so that the width of the plate narrows in moving from fixed end  33  to elevated end  34 . In one embodiment, first tapered side  35  and said second tapered  36  side may terminate on a flat edge surface  37  at elevated end  34 , for both the first and second angled extension plates  30  and  40 . Where the flat edge surface  37  is formed to be parallel to the fixed end  33 , the first angular extension plate and second angular extension plate will each roughly have a trapezoidal shape. 
         [0031]    First angled extension plate  30  may be a flat plate such that top  31  and bottom  32  are planar and parallel to each other ( FIG. 1 ). In a preferred embodiment, first angled extension plate  30  may be flat and so formed to create acute angle  29  relative to the top surface  22  and bottom surface  23  of elongated flat plate  21 . 
         [0032]    The length of the elongated flat plate  21  of the multi-directional scaffold transport device  20  may preferably be sized to span between the peaks of the corrugations of the floor decking shown in  FIG. 5  of U.S. Pat. No. 757,519 to Turnbull, or as shown in  FIG. 5  of U.S. Pat. No. 3,177,619 to Benjamin, or those in  FIG. 2  of U.S. Pat. No. 3,363,379 to Curran. Although the spacing of the peaks of the corrugations used today for the floor decking may vary from building to building, corrugations with a six inches spacing is quite common. Therefore the length of flat plate  21  may, in that instance, be approximately twelve inches or slightly longer, so that when it is attached to the base  13  of a scaffold assembly  11  ( FIG. 7 ), which is being maneuvered across the floor deck&#39;s corrugations, the device will always be supported by at least two peaks. This will be the case where the decking has trapezoidal corrugations offering more stable support from its flat peak surfaces, or the wave-like corrugations. However, the length may be modified to be shorter or longer to suit less common spacing between corrugations, or similar obstacles in other applications. 
         [0033]    The multi-directional scaffold device  20  may be required to support a scaffold having tools or other items atop of it or attached to it, making the overall combined weight to be supported a significant design factor. Therefore, the scaffold device  20  may preferably have vertical stiffeners  51  which may be integral, and may protrude upward from first side  26  and second side  27  of elongated flat plate  21  ( FIG. 3 ). Many alterative embodiments that incorporate vertical stiffeners are possible. A continuous integral wall  52  may protrude vertically from the first end  24 , second end  25 , first side  26 , and a second side  27  of first angled extension plate  30  to form a rectangular-shaped enclosure, as shown in  FIG. 4 . Alternatively, a continuous wall  53  may protrude vertically from only the periphery of the multi-directional transport device, and thereby protrude from first side  26  and second side  27  of elongated flat plate  21 , from first tapered side  35  and second tapered side  36  of both first and second angled extension plates  30  and  40 , and from elevated end  34 , as shown in  FIG. 5 . Also, those various possible stiffener arrangements—stiffeners  51 ,  52  and  53 —instead of being integrally formed, may comprise separate parts which are attached to the device. Shown in  FIG. 2 , is an embodiment where L-shaped angles  54  of different lengths are attached to the periphery of the device to provide stiffness. The attachment means of the angles  54  may include, but is not limited to, welding, and mechanical fasteners such as rivets, screws, nut and bolts, etc. 
         [0034]    To function as an integral part of a typical scaffold, the multi-directional transport device must necessarily be fixed to the scaffolding being used at a particular construction site. A typical scaffold  11  ( FIG. 7 ) may have a leg  12 , that terminates in a base  13 . While there are many possible schemes for attachment of the device to the scaffold base, including, but not limited to, welding, and mechanical fasteners such as rivets, screws, nut and bolts, etc, a preferred embodiment may incorporate threaded studs  60  into the multi-directional transport device  20  that may protrude vertically from top surface  22  of the elongated flat plate  21  ( FIG. 2 ). They may be integral to the elongated flat plate or attached to it by any suitable means, including, but not limited to, welding the threaded studs thereon. Two or more threaded studs  60  would likely be sufficient to attach the device to the base  13  of scaffold  11 , but in a preferred embodiment, four threaded studs  60  may protrude from top surface  22  of the elongated flat plate  21 , and may preferably be spaced in a rectangular pattern. The pattern may preferably be centrally located so as to be approximately mid-way between first end  24  and said second end  25  of said elongated flat plate  21 , and approximately mid-way between said first side  26  and second side  27 . The spacing between adjacent threaded studs  60  should be sufficient to provide adequate clearance from the leg  12  of scaffold  11 . 
         [0035]    The base  13  of scaffold  11  may have holes  14  drilled into it to provide a clearance fit for acceptance of the studs  60 . The multi-directional scaffold device  20  may then be removably attached to scaffold  11  using a conventional fastening mean including, but not limited to, standard hex nuts  65  with lock washers, jam nuts, lug nuts, wing nuts, etc ( FIG. 8 ). The attachment scheme may alternatively incorporate a quick release fastening means for ease of assembly and disassembly onto the base  13  of scaffold  11 . 
         [0036]    Maneuvering of the scaffold assembly  11  would be facilitated with the multi-directional transport device attached, as in  FIG. 8 , to permit sliding movement of the scaffold assembly atop the exposed floor decking of a building&#39;s superstructure, as shown in  FIG. 9 . The relative sliding movement will occur between the bottom surface  23  of multi-directional transport device  20 , and the peaks of the corrugations. The sliding motion will initially be resisted by a static frictional force, which is a threshold that must be overcome, and thereafter by a lesser sliding frictional force. The friction force resisting movement, F f , is determined from the equation, F f =μ·F n , where F n  is the normal force or weight of the scaffold being moved, and μ is the coefficient of friction. 
         [0037]    A coefficient of friction is an empirical property of two materials which are contacting each other, and which provides the relative motion between the two objects. The coefficient can range from near-zero to greater than one, and rougher surfaces have higher coefficients, but most dry material in combination have friction coefficient vales between 0.3 and 0.7. For example, ice on steel has a very low coefficient, whereas a rubber tire on concrete may, under certain conditions, have a coefficient of 1.7. As the coefficient varies dramatically from material to material, this may be a consideration in the material selection for the multi-directional scaffold transport device. The corrugated decking will typically be steel, so materials having a low coefficient of friction in relation to the steel will optimize sliding movement of the scaffold. Teflon has a very low coefficient of friction, often being as little as 0.04, and as such, it is commonly used in spherical bearings. 
         [0038]    The multi-directional transport device  20  may need to be constructed of a relatively high strength metal, but it could also be coated with a finish having a low coefficient of friction, such as Teflon, and enhance sliding movement. Additionally, although there would be a tendency to wear away a coating like Teflon because of the scaffold&#39;s considerable weight and frequent usage, adding a lubricant to the bottom surface  23 , whether coated or not, would improve sliding movement as well as the device&#39;s longevity. The material selected for the multi-directional transport device  20  and any coating that may be used will also alleviate fretting between the moving surfaces. 
         [0039]    As described previously, the length of the elongated flat plate  21  needs to be roughly as long as the straight-line distance between two peaks of the corrugations in the floor decking being utilized ( FIG. 9 ). It should be apparent that the first and second angled extensions permit bi-directional movement of a scaffold fitted with the device, and they also serve to allow the device to climb up to the peak of a corrugation where the scaffold may be maneuvered at an angle relative to the corrugations. With adjustments to the length of the device, a preferred embodiment may traverse at 15 degree angles relative to the axis of the corrugations, or in a more preferred embodiment, traverse at 30 degree angles, but in the most preferred embodiment may traverse at angles of 60 to 90 degrees relative to the axis of the corrugations. 
         [0040]    The device accomplishes multi-directional movement, and not simply bi-directional movement, because many scaffold assemblies incorporate a lever  15  that allow for height adjustments of a particular leg, along with rotation of the base  13 , such as U.S. Pat. No. 6,722,471 to Wolfe. Rotation of the base  13  would also accomplish rotation of the axis  28  of the multi-directional transport device  20  to be re-oriented at a different angle relative to the corrugations. The re-orientation would permit a scaffold that had been pushed diagonally across the floor deck corrugations—at a 45 degree angle for example—to a position where a task was completed, to then have each leg rotated so that the scaffold could then be pushed in a direction at a 90 degree angle relative to its original path, essentially zigzagging across the decking, without having to push the heavy scaffolding along a curved path. 
         [0041]    Although older scaffolding may not be equipped with a lever  15  to permit rotation of the scaffold base, a scaffold leg may nonetheless be fitted with a pivoting base  70  having a base plate  71  and post  72 , as seen in  FIG. 9 . The post  72  may have one or more pairs of orifices  73  drilled in-line through the post  72 , and pairs of holes may similarly be drilled in line in scaffold leg  12 . The leg may then be removeably secured to the based using clamp  80 , which resembles a “C”-clamp that has a “C”-shaped body  81 , which threadably retains a pair of screws  82 . Each screw  81  may have a handle  83  capable of accommodating rotational movement of the screw, so that when the post  71  of base  71  is inserted into the scaffold leg  13 , the ends  84  of clamp  80  may be driven into the in-line holes  74  of the post and the in-line holes  73  of the base. With the scaffold so equipped, and positioned atop corrugated decking, zigzag movement may be accomplished as described for newer scaffolding, by backing out the screws  82  and rotating the base  70 , so as to reorient the multi-directional transport device  20 . 
         [0042]    The maneuverability of the scaffold assembly, with the device attached to the base of each leg, may be further improved in one of several possible alternate embodiments. In one alternate embodiment, first tapered side  35  and second tapered side  36  may converge at the elevated end  34  for first and second angled extension plates  30  and  40 , and rather than a flat edge surface  37  being formed, first and second tapered sides  35  and  36  may converge to create a sharp edge (not shown). This would result in the first angular extension plate  30  and the second angular extension plate  40  each generally taking the form of a triangular shape. Alternatively, instead of converging to a sharp edge at the elevated end  34 , the first and second tapered sides  35  and  36  may be radiused to form a curved surface  38  ( FIG. 6 ), which may be tangent to elevated end  34 . 
         [0043]    It can be seen that curved surface  38  may assist in maneuvering the multi-directional transport device  20 , when attached to a scaffold assembly, around any of the upward protruding floor deck anchor studs. The curved surface  38  would serve to guide the device/scaffold laterally to one side or the other of a floor deck anchor stud, rather than jamming on or butting against the. anchor stud. 
         [0044]    Additionally, instead of angled extension plates  30  and  40  having a top  31  and bottom  32  which would be planar and parallel to each other ( FIG. 1 ), they may both arch upwards whereby first angled extension plate  30  is formed by a curved top  31 A and curved bottom  32 A ( FIG. 3 ). Furthermore, the top and bottom may be comprised of compound curved surfaces, whereby they may also curve upward when moving laterally from centerline  28 , so that first and second angled extension plates  30  and  40  are shaped like the bow of a ship (not shown). This would further ensure that only a curved surface of the multi-directional scaffold device would contact the anchor stud, and prevent jamming against the stud, which would require the user to relocate to the side of the scaffold to jockey it sideways around the stud, rather than just pushing the scaffold from behind. It should be pointed out that the multi-directional scaffold transport device  20 , as well as any alternate embodiment, may preferably be symmetrically formed relative to centerline  28 . 
         [0045]    Lastly, maneuvering the scaffold around the floor deck anchor studs may be further accommodated in an alternate embodiment by having elongated flat plate  21  also incorporate, into first side  26  and second side  27 , tapered edges  26 A and  27 A respectively ( FIG. 6 ). 
         [0046]    The examples and descriptions provided merely illustrate a preferred embodiment of the present invention. Those skilled in the art and having the benefit of the present disclosure will appreciate that further embodiments may be implemented with various changes within the scope of the present invention. Other modifications, substitutions, omissions and changes may be made in the design, size, materials used or proportions, operating conditions, assembly sequence, or arrangement or positioning of elements and members of the preferred embodiment without departing from the spirit of this invention as described in the following claims.