US3804199A

US3804199A - Apparatus for constructing scaffolds

Info

Publication number: US3804199A
Application number: US00267680A
Authority: US
Inventors: H Bondi
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-06-29
Filing date: 1972-06-29
Publication date: 1974-04-16
Anticipated expiration: 1991-04-16

Abstract

A method and apparatus for erecting a scaffold, wherein prefabricated brackets are utilized for supporting a scaffold walkway composed of a number of joined planks. Each bracket comprises a triangularly shaped angle-iron weldment having fastening means by which the bracket may be attached to the edge of a wall, or to the face of a wall if desired, by a single bolt inserted through the wall material. Structural sleeves are provided for evenly joining the walkway planks together, either in straight end-to-end relation or, alternatively, at right angles to one another to permit the scaffold walkway to extend around a corner. The sleeves are designed to make each joint extremely resistant to bending, thereby permitting the various joints to be located at arbitrary locations determined solely by the non-uniform lengths of the various planks utilized rather than by the placement of the scaffold support brackets.

Description

United States Patent Bondi APPARATUS FOR CONSTRUCTING SCAFFOLDS Shoemaker 182/82 [4 1 Apr. 16, 1974 Primary Examiner-Reinaldo P. Machado Attorney, Agent, or Firm-Daniel P. Chernoff; Jacob LVilhauer,Jr,

[57] ABSTRACT A method and apparatus for erecting a scaffold, wherein prefabricated brackets are utilized for supporting a scaffold walkway composed of a number of joined planks. Each bracket comprises a triangularly shaped angle-iron weldment having fastening means by which the bracket may be attached to the edge of a wall, or to the face of a wall if desired, by a single bolt inserted through the wall material. Structural sleeves are provided for evenly joining the walkway planks together, either in straight end-to-end relation or, alternatively, at right angles to one another to permit the scaffold walkway to extend around a corner. The sleeves are designed to make each joint extremely resistant to bending, thereby permitting the various joints to be located at arbitrary locations determined solely by the non-uniform lengths of the various planks utilized rather than by the placement of the scaffold support brackets.

3 l m 4 D awin F s PATENTEBAPR 16 1914 SHEET 1 Bf 2 1 APPARATUS FOR CONSTRUCTING SCAFFOLDS BACKGROUND OF THE INVENTION This invention relates to improvements in methods and apparatus for constructing scaffolds. More particularly the scaffolds are of the type wherein prefabricated brackets support an extended walkway constructed of numerous planks joined together in end-to-end relation.

In bracket-supported scaffolds on the type known to the art, as shown for example in Michalak et al., U.S. Pat. No. 2,882,101 or Vansickle US. Pat. No. 2,279,850, walkways composed of overlappingly spliced planks are normally utilized. Because each overlapping splice constitutes a potential weak point in the walkway, safety consideration dictates that the splices be located only at points corresponding to the placement of the scaffold support brackets in order to minimize the bending stress imposed on the splices. Such predetermined splice location, however, requires a supply of walkway planks having certain minimum and uniform length dimensions, the minimum length of each plank being required to exceed the spacing between adjacent support brackets or' a multiple thereof. Unfortunately the requirement for substantially uniform-planks of predetermined minimum length prohibits the use of odd-length lumber, usually readily available on construction. sites, for building scaffold walkways. Consequently the builder must invest extra money in special lumber reserved for this purpose, adding considerably to his costs. The problem may become further aggravated if each scaffold erected on a particular job cannot, because of the peculiar building design, utilize the same bracket spacing. In addition, the overlapping splices used. to join the various planks cause an abrupt rise or drop-off (depending upon which direction the work man happens to be walking) at those points where the splices are located. Such irregularities in the walkway surface represent a serious potential safety hazard to persons using the scaffold.

While prefabricated brackets have been utilized in the past to eliminate the need for extensive lumber bracing commonly used to support scaffolds, such brackets have been adaptable primarily only for mounting on the face of a wall or to a special-purpose attaching structure, such as the concrete forms shown in the Michalak et al patent. l-Ioweverin certain types of construction only the edges of walls may be available for supporting scaffolds. In such cases the aforementioned conventional face-mounting brackets cannot be used, and thus a need exists for a prefabricated scaffold support bracket which may be attached quickly and reliably to the respective edges of such walls to permit rapid erection and removal of the scaffold.

SUMMARY OF THE INVENTION thus eliminating the need'for positioning each such joint at a point where a scaffold support bracket is lo cated. In addition, the use of the structural sleeves eliminates the safety hazard inherent in the uneven and unreliable overlapping splices. The various sleeves utilized in the present invention are of two types one of which joins two planks in straight end-to-end relation and the other of which joins the planks at right angles to one another to form a scaffold corner.

The use of such structural sleeves is especially beneficial when combined with scaffold support brackets of the prefabricated type, whereby extensive lumber supporting structure beneath the scaffold walkway is eliminated. While the scaffold method and apparatus of the present invention is adaptable for almost any type of construction, it should be mentioned that it has been used to particular advantage in the construction of mausoleums wherein the scaffold is fastened to the edges of reinforced concrete walls, such as crypt walls, with only a single transverse bolt being required to mount each scaffold support bracket to a respective wall. The edge-attaching capability is provided by an angled member on each bracket, such member having a pair of flanges for abutting both the edge and side of a respective wall to prevent skewing of the bracket. Attached to the angled member is a single extended plate through which a transverse bolt passes into the wall at a location behind an integral edge-reinforcing member contained in the wall. Such structure is equally adaptable for fastening to the edge of any other conventional type of wall, regardless of its thickness or composition.

tion is to promote safety by eliminating the need for overlapping splices at the joints between the various planks of the scaffold walkway, thereby eliminating all weak points and unevenness in the walkway.

It is a still further objective of the present invention to provide-a scaffold assembly which may be mounted either to the respective edges or faces of various walls, thereby maximizing the versatility of the scaffold assembly and eliminating the need for lumber bracing regardless of the available mounting surface configurations.

The foregoing and other objectives, features and advantages of the present invention will, be more readily understood upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial perspective view of the scaffold of the present invention showing a prefabricated support bracket attached to the edge of a concrete wall, with several planks of the scaffold walkway shown in phantom to illustrate their relation to the bracket.

FIG. 2 is an exploded perspective view of a facemounted scaffold support bracket utilized in the present invention.

FIG. 3 is a partial extended top view showing several planks of a typical scaffold walkway joined together in the manner of the present invention.

FIG. 4 is a cross-sectional view of a structural sleeve taken along lines 4-4 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT The scaffold assembly of the present invention, shown generally as in FIG. 1, comprises a series of scaffold support brackets of either the edge-mounting type 12 or face-mounting type 14 (FIG. 2) fastened at spaced locations to the available walls or partitions of a building or other structure. In many cases a combination of both types of supporting

brackets

12 and 14 may by used to support a particular scaffold system, depending upon the available mounting surfaces.

The edge-mounting type of support bracket 12 is preferably constructed of three steel angle members 16, I8 and welded together to form a right triangle. A fourth welded member 22 extends upwardly from the end of the horizontal walkway support member 16 and contains a series of apertures 24 by which a handrail post 26 may be attached by any suitable means, such as nails, screws, or bolts.

The vertical member 20 is formed to fit around a vertical corner occuring at the edge ofa wall, such as 28, and includes an extended mounting plate 30 welded at a location between its midpoint and upper end. The plate 30 preferably is of sufficient length that, when the member 20 is in abutment with the edge of the wall 28, the plate 30 extends behind any integral edgereinforcing member such as bar 32, which may be contained in the wall. An aperture is provided near the outer end of the plate 30 through which a fastening bolt 34 may be inserted.

To mount the bracket 12 to the wall 28, a hole is drilled transversely through the wall behind the edgemember 32, and the member 20 is fitted to the corner of the wall. Thereafter the fastening bolt 34 is inserted, and a nut and washer assembly such as 37, 39 shown in FIG. 2 is installed to tighten the bracket to the wall. The vertical counter moment exerted by the single transverse bolt 34, in conjunction with the abutment between the lower end of the flange 20a of member 20 and the end of the wall 28, effectively resists the vertical load placed upon the horizontal member 16 by the scaffold walkway. Moreover the bracket 12 cannot inadvertently be rotated longitudinally because of the counter sideways moment exerted by the bolt 34 and the abutment of the top and bottom ends respectively of the other flange 20b with the side of the wall 28. Thus the foregoing mounting system, while extremely simple in structure and easy to attach, provides a very safe and reliable support for the bracket 12, particularly if reinforcing such as 32 is provided in the edge of the wall.

The face-mounting type of bracket 12 shown in FIG. 2 similarly comprises three triangularly

welded angle members

36, 38, and 40 respectively, and a handrail support member 42. However, because the bracket 14 is intended for attachment to the face of a wall such as 44, only one flange of the angle member 40 is oriented for abutment with the wall. A single bolt 46 and nut and washer assembly 37, 39 fastens the bracket 14 to the wall 44, and thus provides a vertical counter moment for resisting walkway loads comparable to that provided by the edge-attaching bracket 14.

When the

brackets

12 or 14, or a combination of both, have been attached to their respective mounting surfaces at appropriate spaced locations, the planks forming the scaffold walkways may then be laid atop the

horizontal bracket members

16 and 36 respectively. Normally the planks used are two-by-twelves, although other sizes may be employed if desired. Preferably only an inner row of planks 48 (FIG. 1) and an outer row of planks 50 need be provided, the rows being covered with a layer of plywood spanning the longitudinal gap between them.

In order to enable builders to use scrap lumber of nonuniform arbitrary length for the

plank rows

48 and 50, and eliminate the need for overlapping splices, a number of structural sleeves 52 are provided for joining the adjacent ends of the various planks. As best seen' in FIGS. 3 and 4 each sleeve 52 preferably comprises a pair of

steel U-shaped members

54 and 56 respectively, each defining a channel slightly wider than the thickness of the planks, such as 58 and 60, joined by the sleeve. The U-shaped

members

54 and 56 are fastened together at multiple locations along their length by a series of transverse plates 62 which space the U-shaped members apart a sufficient distance to allow insertion of the ends of the adjacent planks. The substantial length throughout which each sleeve 52 engages the ends of each pair of joined planks, coupled with the structural rigidity of the sleeve, provides a joint which is extremely resiste nt to bending moments from vertical loads, making each such joint a point of strength rather than weakness in the scaffold walkway. Consequently it is unnecessary to locate the various joints at particular predetermined positions relative to the respective scaffold brackets to minimize bending stress. Rather the joints may be positioned at arbitrary locations determined solely by the lengths of lumber involved, even if such locations occur at the midpoint between adjacent brackets where bending stress is maximized. Moreover, the use of such sleeves eliminates the unevenness in the Walkway surface caused by overlapping of planks, thereby contributing to safety, and the walkway is made'even smoother by placing a layer of plywood atop the planks as mentioned above.

An alternative embodiment'of the sleeve structure is shown in FIG. 3, comprising a right-angle sleeve assembly 64 capable of perpendicularly joining two planks, such as 58 and 66, to permit the scaffold to extend around the corner of a building. The sleeve assembly 64 is constructed similarly to the sleeve 52 except that two pairs of U-shaped

members

68, and 72, 74 respectively are joined at right angles to one another,

members

68 and 72 respectively being longitudinally offset from their

mating members

70 and 74 so that the corresponding members of each pair'may be welded together at reinforced

joints

76 and 78 toinsure rigidity.

The terms and expressions which have been employed in the foregoing abstract and specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.

What is claimed is:

l. A scaffold assembly having a walkway for spanning the distance between spaced walkway support members, said scaffold assembly comprising a series of planks arranged in end-to-end relation with one another to form said walkway and respective sleeve means for encasing and joining the longitudinal edges of adjacent ends of said planks so as to enable said respective plank joints to resist bending moments imposed by the loads on said walkway, each said sleeve means comprising a pair of parallel elongate members, each elongate member including two opposed rigid elongate flanges joined together in a U-shape adapted for encasing aligned longitudinal edges of said adjacent plank ends, and a plurality of transverse plates attached to said flanges for rigidly joining said elongate U- shaped members together in spaced opposed parallel relation to one another, said flanges which form said U-shaped members extending continuously substantially throughout the entire length of said sleeve means.

2. A prefabricated scaffold walkway support bracket adaptable for mounting to the vertical edge of a solid wall to derive support therefrom, said bracket comprising an elongate member having vertically elongate flanges for fittingly abutting against a vertical corner surface of said wall edge in abutment with the end and one side of said wall respectively, a mounting member projecting from said elongate member at a point above the midpoint of said elongate member so as to extend rearwardly along the side of said solid wall, said mount ing member having a transverse aperture formed therein offset rearwardly from said elongate member, and a bolt adaptable to be inserted through said aperture and transversely through a hole drilled through said solid wall for fastening said bracket to said wall.

3. The bracket of claim 2 wherein said mounting member projects from said elongate member at a point between the midpoint and upper end of said elongate member so as to prevent rotation of said bracket about a horizontal axis extending longitudinally with respect to said wall.

Patent No. 3 so4,199 Dated April 16, 1974 Inventor(s) Herman Bondi -It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 3,. Line 59 Change "bracket 12" to -bracket l4-.

Col. 4,- Line 15 Change "nonuniform" to -nonuniform.

Signed and sealed this 10th day of September 1974.

{SEAL} Attest:

MCCOY M. GIBSON, JR. C.-MARSHALL DANN Attesting Officer 7 Commissioner of Patents USCOMM-DC 60376-P69 f: uos. GOVERNMENT PRINTING OFFICE: was o-sse-saa

Claims

1. A scaffold assembly having a walkway for spanning the distance between spaced walkway support members, said scaffold assembly comprising a series of planks arranged in end-to-end relation with one another to form said walkway and respective sleeve means for encasing and joining the longitudinal edges of adjacent ends of said planks so as to enable said respective plank joints to resist bending moments imposed by the loads on said walkway, each said sleeve means comprising a pair of parallel elongate members, each elongate member including two opposed rigid elongate flanges joined together in a U-shape adapted for encasing aligned longitudinal edges of said adjacent plank ends, and a plurality of transverse plates attached to said flanges for rigidly joining said elongate U-shaped members together in spaced opposed parallel relation to one another, said flanges which form said U-shaped members extending continuously substantially throughout the entire length of said sleeve means.

2. A prefabricated scaffold walkway support bracket adaptable for mounting to the vertical edge of a solid wall to derive support therefrom, said bracket comprising an elongate member having vertically elongate flanges for fittingly abutting against a vertical corner surface of said wall edge in abutment with the end and one side of said wall respectively, a mounting member projecting from said elongate member at a point above the midpoint of said elongate member so as to extend rearwardly along the side of said solid wall, said mounting member having a transverse aperture formed therein offset rearwardly from said elongate member, and a bolt adaptable to be inserted through said aperture and transversely through a hole drilled through said solid wall for fastening said bracket to said wall.