Patent Publication Number: US-6712182-B1

Title: Portable collapsible scaffolding for angled surfaces

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This invention was the subject matter of Document disclosure Program registration number 493431 filed on May 14, 2001. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     REFERENCE TO MICROFICHE APPENDIX 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the field of collapsible scaffolding arrangements in general and in particular to a collapsible scaffolding apparatus specifically designed for angled or uneven surfaces. 
     2. Description of Related Art 
     As can be seen by reference to the following U.S. Pat. Nos. 4,029,173; 4,673,060; 4,576,251; and, 4,153,229, the prior art is replete with myriad and diverse collapsible scaffolding arrangements. 
     While all of the aforementioned prior art constructions are more than adequate for the basic purpose and function for which they have been specifically designed, they are uniformly deficient with respect to their failure to provide a simple, efficient, and practical adjustable scaffolding arrangement that is particularly well suited for angled surfaces such as roof lines. 
     As anyone in the home construction field is all too well aware, the most dangerous area to work on a new home is on the roof due to the complete absence of horizontal support surfaces for not only workmen, but for their tools and materials as well. The angled roof lines not only make stable footing for the workmen a problem, but any unsecured materials or tools that are dropped are prone to sliding completely off the angled roof surface. 
     As a consequence of the foregoing situation, there has existed a longstanding need in the construction trades for a new and improved portable and collapsible scaffolding apparatus that can quickly and easily be erected on an uneven surface to provide a stable horizontal support surface for the workmen, their tools and work materials; and the provision of such a construction is a stated objective of the present invention. 
     BRIEF SUMMARY OF THE INVENTION 
     Briefly stated, the portable collapsible scaffolding apparatus that forms the basis of the present invention comprises in general a pair of support leg units, a support arm unit, a pair of angled brace units and at least one horizontal brace unit that cooperate with one another to form the basic scaffolding apparatus that may be employed either alone or in combination with an identical version of itself depending on the roof structures involved. 
     As will be explained in greater detail further on in the specification, each of the support leg units comprises adjustable length support leg members having upper leg segments and lower leg segments telescopically associated with one another wherein the upper leg segments are connected to one another and to one end of the support arm unit which includes a horizontal support arm member. 
     In addition, the horizontal support arm member is also operatively connected to each of the upper segments of the support leg members by the pair of angled brace units, and the other end of the horizontal support arm member may optionally be provided with either a vertical connector element that is releasably engagable with a vertical wall surface or a horizontal connector element that is releasably engagable with the other end of the horizontal support arm member on a mirror image scaffolding apparatus. 
     Furthermore, the upper leg segments of the support leg members are connected by at least one horizontal brace unit which at least partially supports a D-ring support post that is also supported by one of the support leg members and is provided with an enlarged support arm member. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     These and other attributes of the invention will become more clear upon a thorough study of the following description of the best mode for carrying out the invention, particularly when reviewed in conjunction with the drawings, wherein: 
     FIG. 1 is a perspective view of the basic components of the portable collapsible scaffolding apparatus that forms the basis of the present invention; 
     FIG. 2 is an enlarged detail view of the lower portion of one of the support leg units; 
     FIG. 3 is an enlarged detail view of the adjustable length feature on the support leg units; 
     FIG. 4 is an enlarged detail view of the operative connection between one of the support leg units and an angled brace unit; 
     FIG. 5 is an enlarged detail view of the operative connection of an optional D-ring support post to the basic scaffolding apparatus; 
     FIG. 6 is an enlarged detail view of the operative connection between the pair of support leg units and the support arm unit; 
     FIG. 7 is an enlarged detail view of the addition of a vertical surface engagement bracket with the outboard end of the horizontal support arm unit; 
     FIG. 8 is an enlarged detail view of the upper end of the optional D-ring support post; 
     FIG. 9 is an end view of the arrangement depicted in FIG. 1; 
     FIG. 10 is a side elevation view of the arrangement depicted in FIG. 1; and, 
     FIG. 11 is an enlarged detail view of the connector member used to join a pair of the scaffolding apparatus together. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As can be seen by reference to the drawings, and in particularly to FIG. 1, the collapsible scaffolding apparatus that forms the basis of the present invention is designated generally by the reference number  10 . The apparatus  10  comprises in general a horizontal support arm unit  11 , a pair of support leg units  12 , at least one horizontal brace unit  13  and a pair of angled brace units  14 . These units will now be described in seriatim fashion. 
     As shown in FIGS. 1,  6 ,  7 , and  10 , the horizontal support arm unit  11  comprises an elongated support arm member  20  having apertured inboard  21  and outboard  22  ends and a downwardly depending bracket element  23  disposed at a spaced distance from the outboard end  22  wherein the support arm member  20  is fabricated from hollow tubular stock having a generally square cross-sectional configuration. 
     As can be seen by reference to FIGS. 1 through 6 and  9 , each one of the pair of support leg units  12  comprises an adjustable length support leg member  30  having an upper leg section  31  that telescopically receives a lower leg section  32 ; wherein, the upper  33  and lower  34  ends of the upper leg segments  31  as well as the upper  35  and lower  36  ends of the lower leg segment  32  is provided with a plurality of vertically spaced apertures  37  for reasons that will be explained presently. 
     In addition, the upper leg section  31  is provided with a mounting bracket  38  disposed proximate to, but spaced from, its lower end  34  and the lower leg section  32  is provided with a generally U-shaped foot element  39  that is pivotally secured to the lower end  36  of the lower leg segment  32 . 
     As can best be appreciated by reference to FIGS. 1 through 3, and  6 , the upper ends  33  of the upper leg segments  31  are pivotally secured to one another and the inboard end  21  of the horizontal support arm member  20  and the upper leg segments  31  are secured in a vertically adjustable fashion relative to the lower leg segments  32  by conventional securing elements  40  such as wire lock pins, nuts, threaded bolts, or the like. 
     Turning now to FIGS. 5,  9 , and  10 , it can be seen that the horizontal brace unit  13  comprises at least one horizontal brace member  50  that operatively connects at the lower ends  34  of the upper leg segments  31  to one another; whereas, an optional auxiliary horizontal brace member  50 ′ may be employed to operatively connect the lower leg segments  32  together to provide additional structural rigidity to the scaffold apparatus  10  in a well recognized manner. 
     Furthermore, as shown in FIGS. 1,  4 ,  9 , and  10 , each of the pair of angled brace units  14  comprises an elongated brace member  60  having apertured ends  61   62  that are secured to the bracket elements  38  and  23  on the support leg members  30  and the support arm member  20  respectively to rigidify the operative connection between those members. 
     Turning now to FIGS. 1,  7 , and  10 , it can be seen that in certain instances wherein a vertical wall surface  101  projects upwardly from a roof line  100 , only a single scaffold apparatus  10  is required to create a stable horizontal support surface  200  by use of a vertical connector element  70  on the outboard end  22  of the horizontal support arm member  20  wherein the vertical connector element  70  on the outboard end  22  of the horizontal support arm member  20  wherein the vertical connector element  70  is pivotally secured on the outboard end  22  of the support arm member  20  and temporarily affixed to the vertical wall surface by a conventional securing element  40  in a well recognized manner. 
     In those instances wherein a vertical wall surface  101  is not available, a second identical scaffold apparatus  10 ′ may be operatively connected to the primary scaffold apparatus  10  by use of a horizontal connector element  80  having a plurality of horizontally spaced apertures  81  as depicted in FIG.  11 . The horizontal connector element  80  is dimensioned to be slidably received within the opposed ends  22   22 ′ of the respective horizontal support arms  20   20 ′ and retained therein by conventional securing elements  40  which extend through the apertured ends  22   22 ′ of the respective scaffold apparatus  10   10 ′. 
     As was mentioned previously and depicted in FIGS. 1,  5 , and  8  through  10 , this invention also contemplates the provision of an optional D-ring support post  90  having an enlarged D-ring element  91  pivotally suspended from the upper end  92  of the support post  90  wherein the intermediate portion  93  and lower end  94  of the support post  90  are operatively connected respectively to one of the upper leg segments  31  and the horizontal brace member  50  such that air hoses and/or electrical wires can be threaded through the D-ring element  91  to suspend those hoses and/or wires above the roof line and operatively connect them to the scaffold apparatus  10  so that they do not slide off of the angled roof line. 
     In operation, a pair of leg blocks  150  would be temporarily secured to the roof line  100  to act as braces that the feet  39  of the support leg members  30  could rest against once the length of the support leg members  30  have been adjusted to place the top of the support arm member  20  in the horizontal plane when the vertical connector element  80  of FIG. 11 is operatively deployed thereon. 
     At this juncture, a horizontal support surface  200  such as planking or the like would have one end  201  supported by the horizontal support arm member  20  and the other end  202  would rest on the roof line surface at the same height as the horizontal support arm member  20  of the scaffold apparatus  10  to provide a stable work support surface for the workmen. 
     Although only an exemplary embodiment of the invention has been described in detail above, those skilled in the art will readily appreciate that many modifications are possible without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. 
     Having thereby described the subject matter of the present invention, it should be apparent that many substitutions, modifications, and variations of the invention are possible in light of the above teachings. It is therefore to be understood that the invention as taught and described herein is only to be limited to the extent of the breadth and scope of the appended claims.