Patent Publication Number: US-9903126-B2

Title: Movable scaffold

Description:
FIELD 
     The invention relates generally to scaffolding, and more particularly to movable scaffolding including movable scaffolding bases. 
     BACKGROUND 
     Scaffolds allow workers to reach, and work, at heights outside of their normal reach. Scaffolding has various standard dimensions, materials, and approaches. Scaffolds, and scaffolding as interchangeably used herein, is typically assembled and worked on, and is then disassembled to move to a new location. 
     More recently, approaches to movable scaffolding have been considered. Some of such approaches include motorized movement of scaffolds, for example. 
     However such movable scaffolds suffer from several deficiencies that make them less safe and less practical. It is therefore desirable to manufacture and use a movable scaffold that addresses some of these deficiencies. 
     SUMMARY 
     In one aspect the invention provides a movable scaffolding base for moving an assembled scaffold along a ground surface comprising:
     a frame extending along an elongate axis and adapted for supporting the assembled scaffold;   a drive motor;   a plurality of wheels disposed on the frame and driven by the drive motor;   a control system for controlling the drive motor;   a mounting system disposed on the frame for mounting the assembled scaffold,   at least one outrigger, extending outwards from the frame.   

     In another aspect the invention provides a movable scaffold comprising a movable scaffolding base and a scaffold that is adapted to be removably supported on said base, said movable scaffolding base comprising:
     a frame extending along an elongate axis and adapted for supporting the scaffold;   a drive motor;   a plurality of wheels disposed on the frame and driven by the drive motor;   a control system for controlling the drive motor;   a mounting system disposed on the frame for mounting the assembled scaffold,   at least one outrigger, extending outwards from the frame.   

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments will now be described, by way of example only, with reference to the attached Figures, wherein: 
         FIG. 1  is a perspective view of a movable scaffold, according to an embodiment of the invention; 
         FIG. 2  is a perspective view of the base for the movable scaffold of  FIG. 1  with the outriggers extended, according to an embodiment of the invention. 
         FIG. 3  is a perspective view of the base for the movable scaffold of  FIG. 1  with additional details of the drivetrain, according to an embodiment of the invention; 
         FIG. 4  is a perspective view of the base for the movable scaffold of  FIG. 1  on its side to facilitate storage thereof, according to an embodiment of the invention; 
         FIG. 5  is an enlarged exploded perspective view of a portion of the base for the movable scaffold of  FIG. 1  and its connection with the remainder of the scaffold, according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     A movable scaffold, in accordance with the present invention, comprises a movable scaffolding base  10  that is adapted to support a conventional or modified scaffold  50 . Generally, the structures and methods as herein described permit a conventional or modified scaffold  50 , or portions thereof, to be removably attached to a movable scaffolding base  10 . The movable scaffolding base  10  may be controlled by a worker standing on scaffolding  50  or located nearby. The movable scaffolding base  10  can be stored, as described herein, and may be used to return scaffolding  50  to where it is stored when removed from movable scaffolding base  10 . 
     The figures that follow will illustrate the movable scaffold, the various required and/or optional elements, and the manners by which such movable scaffold and additional elements may be used in practice. 
     Referring now to  FIG. 1 , there is a view of the movable scaffolding base  10  on surface  60  (which may be any surface or combination of surfaces, preferably somewhat level, firm and smooth) and a scaffold  50  attached thereto. 
     As will be described in more detail below, the movable scaffolding base  10  comprises a frame  14  having a front  40 , a rear  42  and two sides  44   a / 44   b  that define horizontal plane  46 . Movable scaffold base  10  further comprises front wheels  16   a , rear wheels  16   b , storage wheels  28 , power source  36 , drive motor  18 , steering actuator  48  and outriggers  24   a - d . Outriggers  24   a - d  further comprise outrigger extending members  36 , extending member holes or connectors  32   a / 32   b  and outrigger wheels  34 . Movable scaffold base  10  further comprises tip guards  26  and bumpers  62  that extend across front  40  and rear  42  sufficiently to cover wheels  16   a  and  16   b.    
     Various functional and structural aspects of movable scaffolding base  10  will be described below, with respect to the figures herein. 
     Scaffold and Connection to Movable Scaffolding Base 
     Scaffold  50  may be substantially any scaffold or portion thereof (referred to herein interchangeably as ‘scaffolding’). Scaffold may be a conventional scaffold such as, but not limited to, works with tube and coupler (fitting) components, prefabricated modular system scaffold components, H-frame/facade modular system scaffolds, and timber scaffolds—provided that scaffold  50  is able to be removably attached or received by movable scaffolding base  10 . Scaffold  50  may also be a modified scaffold as shown in  FIG. 1  and described further below. 
     Scaffold  50  may have one or more vertical scaffold members  52  that may be removably attached to scaffold support posts  22 , as shown in  FIG. 5 . For example, and as shown in  FIG. 5 , scaffold support posts  22  and vertical scaffold member  52  may be tubes (of substantially any shape, such as square or round) such that scaffold support posts  22  (“insertion tube” as depicted in FIG.  5 ) fits within, is enveloped by, or telescopically inserted in, vertical scaffold member  52  (“receiving tube” as depicted in  FIG. 5 ). Of course either may serve as the “insertion tube” or “receiving tube” as desired. Both scaffold support posts  22  and vertical scaffold member  52  may have one or more lock pin holes  502   a / 502   b / 504   a / 504   b . Lock pins  506  may be inserted through corresponding lock pin holes  502   a / 504   a  and  502   b / 504   b  to keep scaffold  50  removably attached to movable scaffolding base  10 . Of course other approaches to maintaining the removable attachment are known to those of skill in the art, including simply the weight of scaffold  50  providing enough attachment through insertion of one tube into the other, overlapping and telescoping members, arms, tubes, tracks, channels, plates, and the like. 
     Scaffold  50  may be modified to further include tie down member  54  that is welded or secured in other known ways to the scaffold structure. Tie down member  54  is adapted to receive a lanyard (not shown) from a worker&#39;s safety harness (not shown) to provide protection against a fall from the scaffold  50 . 
     Frame and Orientations 
     Frame  14 , and any elements of movable scaffold base  10  that may extend outside of frame  14 , may generally be rectangular and with a length of about 1.5-3 meters (sides  44   a  and  44   b ) and width of about 0.75-2 meters (front  40  and rear  42 ). The size and shape of frame  14  is a matter of choice and these dimensions are chosen to enable movable scaffold base  10  to most effectively be used in operation and receive removably attachable standard scaffolds. Frame  14 , and indeed various other elements of movable scaffolding base  10  may be made of lightweight materials, such as metal or aluminum. 
     Frame  14  may define a horizontal plane  46  when movable scaffold base  10  is in position for operation (operation orientation) and receiving assembled scaffold  50 . 
     Frame  14  may also be re-oriented by lifting it onto its side, as shown in  FIG. 4 , for ease of storage and transport. Grab bar  404  may be attached to frame  14  and facilitate movable scaffolding base  10  to be lifted. In such orientation (storage orientation) horizontal plane  46  may substantially be a vertical plane, and movable scaffolding base  10  may be able to fit through narrower spaces and be stored side by side. When in storage orientation movable scaffolding base  10  may rest on floor surface  60  on storage wheels  28  attached on storage posts  402  (which may make it easier for movable scaffolding base  10  to be ‘wheeled around’, or transported, while on its side) together with pivotable stand  406  that may be moved from a first position, adjacent to frame  14  as shown in  FIG. 3 , to a second position, extended from frame  14  to contact surface  60  as shown in  FIG. 4  to support movable scaffolding base  10  in a vertical position. Movable scaffolding base  10  may alternatively rest on one more of wheels  16  (such as the side of one or more wheels  16 ), and/or may lean against wall surface  400  via parts of movable scaffolding base  10  such as wheels  16 . Movable scaffolding base  10  may also be capable of standing in storage position without leaning on anything else. Of course storage wheels  28  may not be required; storage posts  402  and pivotable stand  406  may substantially support movable scaffolding base  10  or may have another attachment at the remote end of storage posts  402 . 
     Stability—Outriggers and Tip Guards 
     Stability of movable scaffolding base  10  may be of particular importance, especially as the height of scaffolding  50  increases, the number of workers increases, ground surface  60  is less reliable or uniform, and the like. 
     Outriggers  24  may provide additional stability and safety to reduce the risk of movable scaffolding base  10  and scaffolding  50  from tipping or rotating in a particular direction. As shown in  FIG. 1 , outriggers  24  may be disposed and attached at various points along frame  14 , such as two outriggers on each side of frame  14  (outriggers  24   a  and  24   b  preventing rotation of horizontal plane  46  towards side  44   a  and outriggers  24   c  and  24   d  preventing rotation of horizontal plane  46  towards side  44   b ). Outriggers  24  may extend outwards away from frame  14  horizontally (such as on side  44   a  or  44   b ), as described herein and may have outrigger wheels that extend downwards toward ground surface and may in fact rest on ground surface  60 . 
     Outriggers  24  may comprise outrigger extending member  36  comprising extending member holes  32   a / 32   b  disposed along the length of extending member  36 , and outrigger wheels  34  which may be removably attached to extending member  36  (such as via nuts and bolts attached to outrigger wheels  34  and extending through extending member holes  32  or via a lock pin). Outrigger wheels may be attached to extending member  36  at substantially any extending member hole  32  though in practice extending member hole  32  that is located most remote from frame  14  along extending member  36  may be used (a ‘remote end’), to maximize the anti-tipping effect. Outrigger wheels may be rotatably attached to extending member  26  such that they are able to roll as movable scaffolding base  10  rolls, regardless of their initial orientation with respect to the direction of motion of movable scaffolding base  10  (such as caster wheels). 
     As shown in  FIG. 2 , outrigger sheaths  204  allow mating of outrigger  24  (via outrigger extending member  36 ) to enable outrigger  24  to telescope relative to sheath  204  and hence frame  14 . Outrigger extending members  36  may couple with sheaths  204  of frame  14 , in substantially a similar fashion to coupling of scaffold support posts  22  and vertical scaffold member  52 . Outrigger pin  208  may be inserted into sheath holes  210  on outrigger sheaths  204  and into one or more extending member holes  32 . 
     As shown in  FIG. 2 , outrigger  24  may be in an extended, or telescoped, position  200   a  and retracted position  200   b  by sliding, or telescoping, outrigger along path  202 —essentially increasing the coupling of extending member  36  and sheath  204 . Extended position  200   a  may be most useful during use of scaffold  50  on movable scaffolding base  10 , while retracted position may be most useful when moving or storing movable scaffolding base  10 . Of course any number of intermediate positions may be defined and used depending, for example, on the height of scaffold, and may be defined via placement of extending member holes  32  or may simply be created as outrigger is telescopically extended outwards or away from frame  14 , such as out of sheath  204 . 
     In addition to outriggers  24 , movable scaffolding base may include one or more tip guards  26  to provide additional stability and safety to prevent movable scaffolding base  10  and scaffolding  50  from tipping or rotating in a particular direction. As shown in  FIG. 1 , tip guards  26  may be disposed and attached at various points along frame  14 , such as one tip guard  26  on front  40  and rear  42  (tip guard  26  on front  40  preventing rotation of horizontal plane towards front  40  and tip guard  26  preventing rotation of horizontal plane  46  towards rear  42 ). Tip guards  26  may comprise a horizontal member connected to a point on frame  14  and may be connected to frame  14  by a member that extends away from frame  14 , such as downward toward ground surface  60 . Tip guards  26  may be aligned on frame  14  such that, if they extended all the way down to ground surface  60 , at least a portion of tip guard  26  would be more remote from the center of frame  14  then the point of contact for the closest wheels (either front wheels  16   a  or rear wheels  16   b ). For example, tip guards  26  located at the rear may essentially be ‘behind’ the point of contact of rear wheels  16   b , to assist in the prevention of tipping towards rear wheels  16   b.    
     Drive and Steering 
     Movable scaffolding base  10  is both drivable and steerable. 
       FIG. 3  shows the primary drivetrain components. Motor  18  may be mounted substantially horizontally on frame  14  with its drive shaft (not shown) pointing along a width of frame  14  (such as parallel to rear  42 ). Rear wheels  16   b  may be attached to rear axle  304 . Rear axle  304  may include a drive sprocket  306 . Drive sprocket  306  may be driven by a chain or belt  302  by drive motor  18  and drive shaft (not shown), which motor sprocket  300  is attached to and turns. It is to be understood that other drivetrain designs are within the scope of the present invention. 
     The steering mechanism includes steering actuator  48  (that may be a linear actuator), actuator motor  54 , and linkage bar  56 . Actuator motor  54  is responsive to the controller and extends and retracts steering actuator to move linkage bar  56  upon receiving power, thus steering front wheels  16   a  right or left. Such steering mechanism, and other similar steering mechanisms that may alternatively be used, are substantially as known by those of skill in the art. 
     Power source  36  provides the power for the platform movable scaffolding base  10 , including drive motor  18 , steering actuator  48  and controller  38 . Power source  36 , in combination with controller  32 , provide power to drive motor  18  and steering actuator, to effect the drive and steering. For added safety, wheels  16  are preferably locked to prevent movement when movable scaffolding base  10  is not driven by motor  18 . 
     Controller 
     Controller  38  allows a user to control the drive and steering of movable scaffold base  10 . Front-to-back movement or drive is accomplished by alternating and/or reversing the direction of rotation of the motor. Steering, or side-to-side motion of movable scaffold base  10 , is accomplished by extending and retracting the steering actuator, as described herein. In one embodiment of controller  38 , there are four buttons: forward, reverse, steer left and steer right. Each button provides a signal to affect the desired drive or steering response, with the forward button causing power from power source  36  to be provided to drive motor  18  (resulting in forward motion), the reverse button causing power from power source  36  to be provided to drive motor  18  to reverse its direction, the steer left button causing steering actuator  48  to extend and the steer right button causing steering actuator  48  to retract. 
     Controller  38  may be connected to power source  36  and, directly or indirectly, to drive motor  18  and actuator motor  54 , via cord  58  (though controller  38  may communicate wirelessly with such components). Via cord  58 , controller  38  may be placed or held on assembled scaffold  50  or on a ground surface  60  upon which movable scaffold rests. 
     Use 
     Movable scaffolding base  10  may initially be stored as shown in  FIG. 4 , and may be stored with other movable scaffolding bases  10  supported on stands  406  or leaning against wall surface and each other. A particular movable scaffolding base  10  may then be removed and put down on wheels  16  via grab bars  404 . Movable scaffolding base  10  may then be moved into place for use, such as via controller  38 , as described herein. Then scaffolding may be assembled thereon, creating an assembled scaffold, so that a worker may climb onto scaffold  50 . Prior to climbing onto scaffold  50 , a worker or other person may extend one or more outriggers to a desired extended and locked position so further assure movable scaffolding base  10  will not tip or rotate. Extending may comprise unlocking or unpinning outrigger  24  from sheaths  204  and telescopically extending them until the desired extended position, at which point locking pin  506  may be repined or reinserted—as such outriggers may be in various lockable and, to varying extents telescoped, positions. If a worker is working on wall surface  400  (such as painting a higher up portion of wall surface  400  then outriggers on the side opposite wall surface  400  may be extended only, as those on the same side as wall surface  400  need not be extended. Having painted a certain portion of wall surface  400  that is reachable from scaffold  50 , a worker may desire to move movable scaffolding base  10  to another position so another part of wall surface  400  may be painted. This may be accomplished by driving and steering movable scaffolding base  10  via controller  38 . Further painting may then be done. Of course, outriggers may be adjusted prior to moving movable scaffolding base  10  or may not need to be, for example depending on the exact nature of wall surface  400  (if curved outriggers may need to be retracted first, for example), ground surface  60  and other factors. 
     When the work is done with assembled scaffold  50  the worker may get down and move movable scaffolding base  10 , then disassemble assembled scaffold  50 , then further move movable scaffolding base  10  so that it can be lifted and put or placed on its side to be stored as in  FIG. 4 . 
     Various modifications and alternatives may be made to the invention. For example, shapes and dimensions of movable scaffolding base  10 , and its subcomponents, may be changed. Outriggers  24  may be foldable or otherwise retractable, and may be done manually or automatically via some powered system. Outriggers may be adjusted to provide different levels of contact with ground surface  60  or to proactively descend or react to tilting or tipping that may occur or be occurring. Movable scaffolding base  10  may have other members, such as to provide additional structural support, as may be required for a particular application. 
     This concludes the description of the presently preferred embodiments of the invention. The foregoing description has been presented for the purpose of illustration and is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is intended the scope of the invention be limited not by this description but by the claims that follow.