Patent Publication Number: US-6340070-B1

Title: Adjustable cantilever scaffolding

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to scaffolding employed to work on the exterior walls of multi-story buildings. More particularly, the invention involves an adjustable cantilever scaffolding to be employed on the upper face of a surface such as a walkway or balcony of a multi-story building and includes a cantilever portion extending over the safety wall of the surface to provide a support for workboards for a workman. 
     2. Description of the Prior Art 
     Maintenance and repairs to the outside walls of multi-story buildings have always proven to be difficult and expensive, especially those buildings that include outside supporting surfaces, such as walkways or balconies, which increases the areas that are difficult to reach. Various techniques have been employed to reach the areas needing work; the more common ones involve the use of stacked scaffolding for the lower floors and suspended scaffolding from the rooftop. Stacked scaffolding becomes impractical as the number of floors increases and safety of workmen becomes a greater problem. On the other hand, suspended scaffolding is difficult, time consuming and expensive to install. Hansen et. at. (U.S. Pat. No. 3,679,026) is the closest prior art known to applicants. It is directed to a scaffolding arrangement employed in constructing a major portion of the outer walls of a building. The scaffolding is set up on the inside of a partially constructed building with an arm of the scaffold extending outwardly of a partially completed outer wall providing support for workboards for the bricklayer to stand on to complete a major portion of the outer wall. Portions of the wall in the shape of a window or similar opening are left unfinished in the wall in order to retract the support arm as the scaffolding is removed. The unfinished openings in the wall are later closed by using scaffolding suspended from the roof. 
     Accordingly, it is an object of the present invention to provide a novel scaffold assembly that is mounted on an exterior horizontal surface of a building, such as a walkway or balcony, that includes cantilever means extending outwardly thereof to provide support for a worker. 
     A more specific object of this invention is the provision of a novel, fully adjustable scaffold assembly that is mounted on the upper face of a walkway or balcony of a multi-story building. The scaffold assembly utilizes a cantilever support beam extending over the balcony safety wall to support a worker. 
     A further object of this invention is to provide a novel scaffold assembly mounted on the surface of a walkway or balcony having a safety wall, the scaffold assembly includes a cantilever support beam extending over the safety wall for supporting a first worker and a second support suspended from the support beam and extending to a level below the worker to carry a second worker. 
     Another important object of the present invention is to provide a novel scaffold assembly that is mounted on an exterior horizontal surface of a multi-story building such as a walkway or balcony that includes a safety wall. The scaffold assembly includes a cantilever support beam that extends over the safety wall, and when positioned on the horizontal support surface, most components of the assembly are near the periphery of the support surface. This construction provides ample obstruction-free space on the support surface which permits unencumbered movement of workmen around the scaffold. 
     SUMMARY OF THE INVENTION 
     The present invention alleviates many of the problems encountered in using conventional scaffolding. Specifically, this invention provides a novel adjustable cantilever scaffold apparatus to easily access the more difficult to reach areas around the balconies of multistory buildings. The entire scaffold structure is mounted on the floor of a balcony or similar structure and includes cantilevered beams extending outwardly over the wall of the balcony to support workboards for the workers. Most components of the assembly are positioned near the periphery of the support surface when assembled to permit unencumbered movement of workmen around the scaffold. 
     These and other important objects and advantages of the invention will become apparent as this description proceeds. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIG. 1 is a perspective view of the scaffold assembly constructed in accordance with the invention; The optional support for a second workman is illustrated in a separated condition for sake of clarity; and 
     FIG. 2 is a somewhat schematic illustration of the scaffold assembly in use on the side of a multi-story building. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings and particularly FIG. 1, a scaffold assembly in accordance with the invention is generally designated by the reference numeral  10 . The assembly  10  is mounted on a balcony b having a safety wall c on an outer wall of a multi-story building b, see FIG.  2 . (It should be noted that for purpose of simplicity the scaffold assembly  10 , of rule invention is described herein as mounted on a balcony of a multi-story building b. It is obvious that the assembly can be mounted on any type of horizontal walk surface on the exterior of the building.) The scaffold assembly  10  includes a support foot  11  positioned transverse to the length of the floor of the balcony b. Support foot  11  is provided along its length near the mid-point with laterally extending stabilizing arms  12  to eliminate any tendency of tilting by the scaffold. The stabilizing arms  12 , which include sloping upper surfaces to permit passage of wheelbarrows, can be of any desired length and are provided with slots  13  adjacent the ends to serve as handles to assist in portability. The length of the foot  11  can vary as discussed in greater detail below, but should be at least of sufficient length to permit the passage of workmen and wheelbarrows thereover. The outer end of the foot  11  is positioned adjacent the base of safety wall c and is adjustably positioned within a lower adjusting sleeve  22  secured to the lower end of telescoping standard indicated generally at  14 . Telescoping standard  14  includes an outer post  16  rigidly secured to lower adjusting sleeve  22 , an inner post  18  adjustably positioned inside said outer post  16  and having upper adjusting sleeve  20  rigidly secured thereto. A carrying handle  19  is secured to outer post  16 . The length of telescoping standard  14  is adjusted to insure that upper adjusting sleeve  20  is located at a preferred level above the upper edge of safety wall c. Slidably received within upper adjusting sleeve  20  is the inner end of cantilever support beam  24 , the outer end of the support beam  24  extends horizontally outward beyond the top of safety wall c for a distance sufficient to carry workboards  26  to support a workman. Secured to the outer end of support beam  24  is an upright safety standard  28  which confines the walkboards  26  on support beam  24  and carries safety means  30  (FIG. 2) such as rope, chain or boards for protection of the workmen. 
     While not illustrated for sake of simplicity, it should be noted that bracing extending at angle between inner post  18  and cantilever support beam  24  can be employed to ensure safety of the workmen. When bracing is employed, the inner post  18  must extend above the top of safety wall c a sufficient distance (see FIG. 2.) to provide space for the same. 
     The scaffold assembly  10  of this invention can optionally carry additional scaffold mechanism designated generally at  40  providing for workmen on a lower or second level below the first working level. FIG. 2 schematically illustrates this arrangement under working conditions. Mechanism  40 , best illustrated in FIG. 1, includes tubular support standard  42  that is adjustably secured inside safety standard  28 , a horizontally extending support beam  44  rigidly secured to standard  42  to support a second level of workboards  26  thereon and safety restraint brackets  46  which also function as carrying handles. When properly positioned, mechanism  40  will position the workman on a lower level to work on the next lower balcony. 
     The adjustability of the scaffold assembly  10  of this invention is important in that it provides the ability to fit the scaffold to the work area. Any kind of adjustment means can be employed, however, we prefer to utilize the well known combination of slidable fittings employing alignable adjustment holes with locking pins inserted therein to secure the pieces in adjusted position. The adjustable connections for the foot  11  and lower sleeve  22  are shown at  50  and  56 , the adjustment holes for the outer post  16  and the inner post  18  of the telescoping standard  14  are shown at  58 , the adjustable connection between the upper sleeve  20  and the support beam  24  are shown at  52  and  60 , and the adjustable connection between the safety standard  28  and the support standard  42  of the scaffold mechanism  40  are shown at  54  and  62 . The conventional locking pins employed in these connections can be of any well known construction and for sake of simplicity has not been illustrated. 
     In use, the manner in which the adjustable scaffold assembly  10  of the present invention is secured on the surface of the balcony b is also an important part of this invention. As pointed out above, the support foot  11  should be of a length of sufficient to provide for the passage of a wheelbarrow thereover between the upright telescoping standard  14  and the means anchoring the support foot  11  to the balcony b. The anchoring means comprises a conventional jack screw  32  (FIG. 2) that is fixed between the support foot  11  at its lower end and the underside of the balcony above at its upper end as is well known in the building construction art. The location at which the jack screw  32  is placed along the length of the support foot  11  is important. Theoretically, the jack screw  32  can be positioned at any point along the length of support foot  11  from a position closely adjacent telescoping standard  14  to a position at the rear end of support foot  11  adjacent the wall of building b and such range of placement is deemed to be within the scope of this invention. However, placement of the jack screw  32  along the length of the support foot  11  a distance substantially equal to the adjusted length of the support beam  24  is preferable in order to utilize the mechanical advantage of such placement to counteract the resulting downward forces on support beam  24  when in use by a workman. Such placement also provides the desired spacing to permit workmen and wheelbarrows to pass between standard  14  and jack screw  32 . Movement of jack screw  32  further away from telescoping standard  14  along the length of support foot  11  and closer to the exterior wall of building b simply enhances the mechanical advantage of the system and opens up the unencumbered space for movement of workmen and materials. It is noted that in use the scaffold assembly employs two laterally spaced and aligned identical assemblies  10  that cooperate to provide means for supporting the walkboards  26  suspended therebetween. This arrangement of scaffolding is well known in the art as shown in the patent to Hansen et. al. discussed above. See FIGS. 1 and 4 and the related description thereof. Accordingly, this conventional arrangement has not been specifically illustrated although FIG. 2 herein is an end view of the scaffold assembly of this invention wherein two such assemblies  10  are employed to provide the necessary support for walkboards  26 . 
     The materials employed in constructing the adjustable cantilever scaffold assembly  10  of the present invention comprise heavy steel rectangular tubing that prevents relative rotation of components at the adjustable connection and that are capable of carrying the loading presented by this invention. Obviously, any materials and/or configuration of material. That is capable of carrying out this invention is deemed to be within the scope of this invention. 
     While the scaffold assembly of the present invention has been disclosed for employment on previously constructed buildings wherein the safety walls on walkways, balconies, etc have been installed it is also intended that the scaffold assembly hereinalso be employed on buildings that are under construction. In some instances it could be necessary to employ the scaffold assembly on walkway or balcony surfaces that have not been provided with the usual safety walls. Although, safety walls are preferable, it is obvious that the present invention can meet it&#39;s objectives with or without such safety walls being installed. 
     While a preferred embodiment of the present invention is shown in the drawings and described above, it is to be understood that those skilled in the art will readily appreciate that certain modifications, changes and substitutions may be effected with regard to the disclosed structure, insofar as these modifications, substitutions and alterations fall within the spirit and scope of the present invention as defined by the claims appended hereto, they are contemplated.