Patent Publication Number: US-2013233646-A1

Title: Mobile and Stabilizing Scaffold Apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 61/607,853 filed on Mar. 7, 2012, entitled “Scaffolding Railway.” The above identified patent application is herein incorporated by reference in its entirety to provide continuity of disclosure. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to scaffolding and other structures for supporting a worker during installation, repair, and inspection operations. More specifically, the present invention pertains to a mobile scaffolding structure that provides outriggers and extension members for supporting a scaffold planking platform in a level configuration across uneven or sloping support surfaces, while also allowing the user to slide the platform along its supports into a desired location. 
     Scaffolding is temporarily erected structure that elevates and positions maintenance and construction workers in otherwise difficult positions against buildings and other structures, whereby the worker is supported or provided stable platform to engage in his or her work activities without fear of falling. Of primary importance is the stability and safety of the structure, where the worker must be given adequate access, sufficient space to stand or work, and further provide access to a work area without straining or making the task a difficult or dangerous one to complete. Traditional scaffolding includes erected structures having vertical tubes, couplers, and boards that form a series of levels that allow a worker to stand in close proximity to a work area, whereby the vertical tubes are supported by the ground surface therebelow and the boards provide a level standing platform. 
     Traditional scaffolding usually offers narrowly spaced supports that are positioned relative close to one another along the support surface. This presents a problem when working on uneven or sloping surfaces, as the upstanding tubes that support the scaffolding are projected upwards at an angle or at different angles from one another. Leveling the scaffolding boards therefore becomes difficult, and further tends to make the scaffolding structure unstable or at risk of tipping. The primary goal of the scaffolding is safety and stability, while also providing convenient access to a work area for a user. Therefore, it is important to provide scaffolding that can adapt to different environments and support surface types, whereby the level of the user support remains level and the overall structure remains stable. 
     This is particularly true when erecting scaffolding within cargo holds, oil tanks, or other enclosed ship structures having sloping floors. These locations generally have confined space within which to erect scaffolding, and generally include sloping floors that may otherwise create an issue when leveling the scaffolding in proximity to the tank sides. A stable and conformable scaffolding structure is required, wherein the grade of the support surface can be accounted for without expending too much effort during the scaffolding installation process. 
     The present invention provides a new and novel scaffolding structure that supports an elevated user on a platform, while providing an expandable and vertically stabilizing structure that can account for changes in the grade of the floor or to uneven terrain. The present invention provides a scaffold assembly that is ideally suited for confined areas and on non-level surfaces, whereby stabilizing members allow the user platform to remain level while the scaffold can be rolled into a desired location and stabilized at different locations along the floor. When deployed in the tanker or shipping industry, the present invention facilitates users cleaning and treating the inner walls of a ship hold while remaining level therein and in close proximity to its inner walls. The stabilizing jacks and roller wheels allow for stable positioning and ready repositioning along the cone-shaped floor of an oil tank. Oilfield workers, tanker ship workers, or those who work on sloping or uneven terrain may appreciate the flexibility and efficiency of the present apparatus. 
     2. Description of the Prior Art 
     Devices have been disclosed in the prior art that relate to scaffolding structures. These include devices that have been patented and published in patent application publications, and generally relate to scaffolding of varying structural design and purpose, None of the prior art devices describe a movable and stabilizing scaffold support structure that is ideally suited for use in oil tanks or other confined areas having non-level floors. The following is a list of devices deemed most relevant to the present disclosure, which are herein described for the purposes of highlighting and differentiating the unique aspects of the present invention, and further highlighting the drawbacks existing in the prior art. 
     Specifically, U.S. Pat. No. 4,828,073 to Friday discloses a mobile suspended scaffold that includes roller wheels for movably supporting a scaffold between roof purlins or similar structural beams of a building. First and second parallel rails are supported along parallel purlins by way of roller wheels on each rail. Transverse members secure the first and second rails together, providing a frame to support platforms or scaffold members thereto. The roller wheels are secured to Z-beam or C-beam purlins and allow the frame to be slideably mounted thereto. The Friday device, while providing a unique scaffold support that includes adjustability of the frame, fails to disclose the novel aspects of the present scaffold support, which includes length and height adjustable supports for positioning the scaffold in a level configuration when working on otherwise sloping or uneven ground. 
     Other patents have been disclosed relating to scaffolding systems within the hulls or volumes of shipping vessels, including liquefied natural gas tanks and other cargo holds. These include U.S. Pat. No. 4,057,943 to Lienhard, U.S. Pat. No. 6,659,226 to Sarrazy, and U.S. Patent Application Publication No. 2007/0205051 to Yang. These devices describe large structures that are suspended or otherwise supported within the interior of a ship cargo hold for the purposes of facilitating cleaning or painting operations. These devices allow a work to be suspend over or supported from the uneven ground of a cargo hold or be able to approach otherwise non-uniform cargo hold wall surfaces. These devices, while presenting diverse and novel means of erecting scaffolding within shipping holds, do not describe the adjustably supported scaffold of the present invention, which is supported from a ground surface and can be slid therealong despite the support surface being otherwise uneven or sloping. One of the contemplated uses of the present invention is within the interior of shipping holds, which include sloping floors. 
     The present invention discloses a stable scaffolding platform that includes extendable members that support the platform in discrete locations offset from the platform such that the platform remains level over non-uniform or sloping surfaces. The assembly is collapsible into a transportable structure, whereby it can be rolled into a desired position, thereafter extension members are deployed and support jacks level the assembly for stabilized and level footing for the user while on the elevated platform. The device is contemplated for use in construction and maintenance operations, where the platform can be easily positioned and leveled on otherwise non-level floor surfaces. It is submitted that the present invention is substantially divergent in design elements from the prior art, and consequently it is clear that there is a need in the art for an improvement to existing scaffold devices. In this regard the instant invention substantially fulfills these needs. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing disadvantages inherent in the known types of scaffolding now present in the prior art, the present invention provides a new scaffold apparatus that can be utilized for providing convenience for the user when operating over uneven or sloping surfaces during work operations that required the user to be elevated above the ground level to reach a work area. 
     It is therefore an object of the present invention to provide a new and improved scaffold apparatus that has all of the advantages of the prior art and none of the disadvantages. 
     It is another object of the present invention to provide a scaffold apparatus that includes a frame, an elevated platform, and extendable members from the frame that include height adjustable jacks to control the pitch of the frame and thus control the level of the elevated platform thereabove. 
     Another object of the present invention is to provide a scaffold apparatus that can be deployed in tight confines and over sloping or uneven surfaces, providing a tool to elevate a working towards a work area while providing a stable and level support therefor. 
     Yet another object of the present invention is to provide a scaffold apparatus having a frame that can be wheeled into a desired position before deploying its extension members for leveling and stability purposes. 
     Another object of the present invention is to provide a scaffold apparatus that comprises a structurally stable frame and support for its elevated platform, ensuring safety of the elevated worker and the longevity of the apparatus after extended periods of deployment. 
     Other objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
       Although the characteristic features of this invention will be particularly pointed out in the claims, the invention itself and manner in which it may be made and used may be better understood after a review of the following description, taken in connection with the accompanying drawings wherein like numeral annotations are provided throughout. 
         FIG. 1  shows a perspective view of the present invention in a stowed state, ready to be rolled into a working position. 
         FIG. 2  shows a perspective view of the present invention in a working state with its extension members are in a deployed state, stabilizing the apparatus for a worker to stand thereon. 
         FIG. 3  shows a close-up view of the frame and extension members of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference is made herein to the attached drawings. Like reference numerals are used throughout the drawings to depict like or similar elements of the present scaffold apparatus. For the purposes of presenting a brief and clear description of the present invention, the preferred embodiment will be discussed as used for providing a rolling scaffolding platform that can be stabilized over uneven or sloping surfaces using an expandable frame and elevated scaffold platform to facilitate work activities. The figures are intended for representative purposes only and should not be considered to be limiting in any respect. 
     Referring now to  FIG. 1 , there is shown a perspective view of the scaffold apparatus of the present invention in a stowed state and ready for positioning in a desired location. The apparatus is one that is capable of supporting at least one worker and a quantity of worker equipment in an elevated position with respect to the ground, facilitating the ability of the worker to reach higher positions along a wall or reach a ceiling surface. In the state as shown in  FIG. 1 , the device is in its most collapsed state, whereby the assembly can be rolled via roller wheels  20  into a desired location before deploying its stabilizing members  17  into a working position. The apparatus is one that is ideally suited for use in confined areas and along surfaces that have uneven, sloping, or non-uniform support surfaces, where stabilizing and leveling the elevated platform  11  may otherwise be difficult, and therefore working thereon could pose a safety risk for the worker. 
     The apparatus comprises a lowermost frame  12  having a set of parallel longitudinal members  13  forming the sides of the frame, and a forward  15  and rear  14  cross member forming the ends of the frame to provide a largely rectangular structure from which stabilizing members  17 ,  16 , roller supports  20 , and the elevated platform  11  are supported. The frame longitudinal members  13  include elongated and tubular passageways through which the rear extension members  17  are supported, whereby the rear extension members are shaped to correspond with the longitudinal frame member tubular interior such that the rear extension members  17  telescope therefrom and are slideably supported within the frame longitudinal members  13 . The rear extension members  17  are capable of deploying from the frame or stowing thereinto. At the end of the extension members  17  is supported a vertical stabilizing member  25  that is movably positioned in a vertical direction using a jack assembly  25 . The jack assembly  25  is a crank mechanism having a hand crank and internal gearing to control the extension and retraction of the shaft-mounted jack pad  19 . The jack assembly  25  allows a user to determine the vertical positioning of the jack pad  19  at the base of the jack assembly  25 , whereby the pad contacts the ground surface and lifts the corner of the frame  12  according to its height for stabilization and leveling purposes. When stowed, the jack pad  19  is positioned above the ground surface and the roller wheels  20  of the frame support the apparatus. In lieu of a jack assembly  25 , the jack pads  19  can be threadably supported by the extension members  17 ,  16  or otherwise removably securable thereto. However, the jack assembly provides the easiest and robust means of controlling the jack pad  19  position and raising or lowering the jack pads  19 . 
     Along the corners and side midpoints of the frame  12  are junctions  18  that slideably support the forward stabilizing members  16  therethrough. The forward stabilizing members  16  are comprised of the same tubular structure as the rear stabilizing members  17 ; however these members  16  are supported within open support junctions  18  at the corners and side midpoints of the frame  12  above the frame longitudinal members  13 . The embodiment shown in  FIG. 1  supports the forward stabilizing members  16  openly along the frame  12 , whereby the junctions provide support therefor at specific locations along the frame. In an alternate embodiment, the forward stabilizing members  16  are slideably supported within an enclosed frame member, whereby the members  16  telescope therefrom in the same fashion as the rear members  17 . In either embodiment, the frame  12  provides for slideable support for the extension members  16 ,  17 , wherefrom the members can extend or retract into the frame to provide outriggers or stabilizing points for the frame outside of its limits. 
     Along the forward portion of the frame, a forward cross member  15  connects the two parallel longitudinal members  13  together and provides an internal conduit for which extendable roller wheels  20  are supported. The forward roller wheels  20  are slideably supported by the forward cross member  15 , whereby roller wheel extension members  21  allow the wheels  20  to be positioned outside of the frame  12  limits or at the forward corners thereof. The members  21  telescope into the forward cross member  15  in the same fashion as the forward  16  and rear  17  stabilizing members, whereby the roller wheel extension members  21  are sized to slide therein. This configuration allows the forward wheels  20  to be positioned outward from the frame  12  for increased lateral stability of the overall apparatus. 
     Along the rear corners of the frame are the rear roller wheels  20 , which do not extend therefrom. Both the forward and rear corner wheels  20  are pivotably mounted such that the wheels can be directed in a desired direction when rolling the scaffold apparatus in a desired direction and to a work site. When the desired position is achieved, the roller wheels  20  can be locked, whereby the wheels are prevented from rolling, thereby preventing the apparatus from rolling away or shifting as the user climbs the elevated platform. This is necessary to prevent the apparatus from shifting as the worker moves, whereby changes in momentum of the worker would induce the apparatus into moving to conserve momentum, creating a risk of falling for the working as the platform  11  moves under him. 
     Attaching directly to the frame  12  is the elevated platform  11 , which secures to the frame  12  at four discrete locations. The platform comprises four vertical supports  30  that extend upward from the frame  12  and support a platform  31  or planks thereabove for a worker to stand and for equipment to be placed. Platform cross members  32  connect adjacent vertical supports  30  along each side of the frame, while cross braces  34  support the vertical supports  30  across the width of the frame below the support platform  31 . A stable, rectangular support platform  31  is therefor provided for a user thereabove. To allow egress and ingress of the worker, the vertical supports  30  may include ladder rails  33  therealong, allowing the worker to climb the apparatus after the wheels  20  have been locked and the extension members  17 ,  16  are extended and secured against a ground surface. This allows the user to aggressively traverse the rails  33  without the apparatus shifting or tipping under his or her load. 
     Referring now to  FIG. 2 , there is shown perspective view of the scaffold apparatus in an extended and deployed state, wherein the front  16 , rear  17 , and roller wheel  21  extension members are positioned away from the frame  12  and the jack pads  19  and roller wheels  20  are vertically positioned such that the upper platform  31  is in a level and stable position with respect to the ground surface. During deployment of the extension members  16 ,  17 ,  21 , there is an outer extent with which the members may be deployed before a stop or lock prevents them from complete separation with respect to their frame sleeves. This stop may include a spring plunger lock mechanism  45 , as shown along the rear frame in  FIG. 2 , or the stop may be a change in the internal geometry of the frame interior that prevents separation of the members. This internal geometry may include a step in the cross section of the frame interior with respect to the sliding members, or another catch-style stop that prevents the members from pulling completely out of the frame during operation. This stop feature is desired to prevent the members from being deployed to an extent that their connection with the frame is minimized and thus their ability to counteract shifting loads from the apparatus may otherwise be compromised. The spring plunger lock mechanism  45  is a spring biased pin that slides into a receiving aperture in the member to lock the position of the member and the frame at that location, whereafter the pin lock can be withdrawn to release the given member for free sliding. 
     Referring now to  FIGS. 2 and 3 , the extension members are shown in a deployed state with respect to the frame  12 . The forward extension members  16  slide relative to the frame  12  and are received by an upper tubular member or the upper portions of the frame junctions  18 . Once deployed, the members  16 ,  17 ,  21  locate the jack pads  19  and roller wheels  20  outside of the frame  12  limits, creating supports or outriggers that broaden the base of the apparatus to prevent tipping and allow the frame to remain level over uneven surfaces. The pads  70  of the jack pad assemblies  19  are deployed by the jack assemblies  25 , whereby the pad  70  is extended downward to establish a firm footing on the surface or to raise that frame at the given location of the pad  70 . Similarly, the front roller wheels  20  articulate vertically by way of the jack assemblies  25 , whereby the roller wheels  20  can lift above the ground or be used to elevate the platform for moving the apparatus. To secure the device wheels are locked using a wheel lock assembly  70 , which prevents rotation of the wheels and hence no rolling movement. 
     In use, the present scaffold apparatus provides a mobile and locatable structure that supports a worker in an advantageous position relative to a work area, while provide stable footing therefor such that the worker support remains level and static while deployed. The device is ideally suited for sloping floors, uneven terrain, or non-uniform surfaces, whereby the extension members form outriggers that prevent sliding, tipping, and further allow the assembly to remain level across large changes in floor grade. One particularly contemplated application area is within the interior oil tanks, which require maintenance over intervals to ensure proper function of the tank. When working inside an oil tank, workers often use scaffolding to reach the top of the tank. However, the floors are generally slanted, making it difficult and time consuming to stabilize the scaffolding, and sometimes impossible. In a confined space like an oil tank, standard scaffolding will not fit through the narrow opening in the tank. The scaffolding currently used in the industry can easily tip over and it can be hard to move around on the cone-shaped floors. The present invention provides a scaffold apparatus that can fulfill the needs of such an environment, providing a readily deployed, stable, and safe support for a worker within the oil tank. 
     It is submitted that the instant invention has been shown and described in what is considered to be the most practical and preferred embodiments. It is recognized, however, that departures may be made within the scope of the invention and that obvious modifications will occur to a person skilled in the art. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. 
     Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.