Patent Application
20080168740
The present invention relates to a support structure of scaffold pipe, framework construction, and more particularly the invention relates to an improved mud sill that attaches to a base foot plate of a scaffold like framework. The scaffold assembly is constructed from tubular alignments having plural, singular, and vertically arranged rigid horizontal frames. A frame is typically a rectangular construct but can also be triangular in configuration. The other ends of the upright corner post elements of such vertical frames interconnect at two corners. The mud sill is the lowest element for a scaffolding foundation which rests between the lower steel baseplate of screw jack and the ground upon which the scaffolding stands. In order to distribute vertical load on the ground that may shift, the baseplate is typically nailed to a mud sill. The mud sill may be an elongated eight by ten which is disposed under and fastened to a number of parallel baseplates with nails or it can consist of sections of shorter two by ten lumber that is attached to an individual baseplate.
General requirements of OSHA regulations (Section 1926.451c) in connection with the criteria for supporting scaffold provides that the supported scaffold poles, posts, frames, and uprights shall bear on baseplates and sills or other adequate firm foundation.
Scaffolding to support workers above the ground during construction is well-known in the art and many variations have been considered. One very common type of scaffolding used during construction of a wall or other structure includes a set of four uprights, bridged by sets of horizontal support members. Cross-braces extend between pairs of uprights to stabilize the scaffolding. The horizontal support members provide a frame across which a set of planks, typically made of wood, are laid to form a platform upon which workers can stand. As progress is made during construction, the horizontal support members are raised and locked in place at new heights, allowing workers standing atop thereof to work on higher sections of the wall being constructed. Additional uprights can be affixed atop the scaffolding, thus allowing higher levels of horizontal support members and platforms to be put in place.
Scaffolding of this nature is generally ground-based: supported on the ground surface. When supported on the ground surface, the uprights are typically placed atop swivel base screw jacks for leveling the scaffolding. The base of each screw jack typically has a flat baseplate that is nailed to a wood block or an elongated board, i.e. mud sills, that are placed on the ground. The mud sills distribute the weight of the scaffolding over a larger area of the ground than provided by the baseplate ends of the uprights to inhibit the uprights from sinking into the ground.
Although the above-described scaffolding is common, it is time consuming to erect. Also, during construction of such scaffolding, care must be taken to ensure that the uprights firmly rest on the ground and, thereafter, that each horizontal support member is level. As the scaffolding is generally free-standing, it is also important to ensure that the scaffolding is stable. As will be appreciated, slight shifting in the ground can result in unstable scaffolding or, even worse, its collapse. Of particular concern is the time and effort required to attach mud sills to the scaffolding which typically requires that the baseplate be nailed to the wood block or board. Fastening is often done using a minimum number of nails when a maximum of four nails could be used. Additionally, nails are often hammered in only part of the length of the nail and then bent over, leaving the fastening weaker than it would be if the nails were fully inserted by hammering. Another disadvantage to the use of current mud sills is when the scaffolding is taken down or reconfigured, the mud sills are generally removed from the baseplate, which means that additional labor is required to extract the nails and then the nails, discarded as bent nails, are seldom reused.
To alleviate this problem, and others which will become apparent from the disclosure which follows, the present invention conveniently teaches an improved mud sill that is easy to install and remove with a minimal amount of labor required. The improved mud sill attaches securely to the baseplate of a screw jack or scaffolding assembly without the use of extraneous fasteners, such as nails or screws. The improved mud sill is generally disk shaped with a top surface and a bottom surface and an axis extending between the top surface and the bottom surface. A multi-layered recess is provided in the improved mud sill to receive a baseplate axially and then the improved mud sill is rotated relative to the baseplate to secure it in place. Once installed the improved mud sill of this important invention is restricted three dimensionally to the baseplate and yet it can easily be removed by a counter-rotation from the installation process. Time and labor costs are substantially reduced.
These together with other objects of the invention, along with the various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
Still other advantages will be apparent from the disclosure that follows.
According to one aspect of the invention, an improved mud sill, for use with a generally horizontal baseplate of a base of a vertical scaffolding member, is taught comprising a foot with a transverse dimension measured in all directions that is substantially greater than each dimension in a parallel direction of the generally horizontal baseplate, and with a top surface that has an opening, a bottom surface, and an axial dimension, measured between the top surface and the bottom surface, that is perpendicular to the transverse dimension of the foot. The top surface has an internal peripheral edge defining the opening and a recess extends axially from the opening. The recess is suitably sized to receive the baseplate of the scaffolding member, so that the baseplate can be disposed in the recess of the foot and the weight of the vertical scaffolding member can be distributed over the transverse dimension of the foot of the mud sill. Preferably, a drain hole extends from a lower surface of the recess to the bottom surface of the foot.
According to another aspect of the invention, an improved screw jack is taught with a generally horizontal baseplate secured to a bottom end of an externally threaded screw and an internally threaded wing nut, for use with a base of a vertical scaffolding member that can rest on the wing nut, the screwjack comprising a mud sill, having a transverse dimension measured in all directions that is substantially greater than each dimension in a parallel direction of the generally horizontal baseplate, with a top surface that has an opening, a bottom surface, and an axial dimension, measured between the top surface and the bottom surface, that is perpendicular to the transverse dimension of the mud sill. The top surface has an internal peripheral edge defining the opening and a recess extends axially from the opening. The recess is suitably sized to receive the baseplate of the scaffolding member, so that a top end of the moveable screw can be inserted into the base of a vertical scaffolding member and the generally horizontal baseplate can be disposed in the recess of the mud sill and the weight of the vertical scaffolding member can be distributed over the transverse dimension of the mud sill.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
In the following description, specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent that the invention may be practiced without these specific details.
The present invention teaches an improved mud sill 1 that is easy to install and remove with a minimal amount of labor required. The improved mud sill attaches securely to the baseplate 20 of a screw jack 24 or scaffolding assembly without the use of extraneous fasteners, such as nails or screws, as shown in the prior art uses in
Without departing from the generality of the invention disclosed herein and without limiting the scope of the invention, the discussion that follows, will refer to the invention as depicted in the drawing.
According to one embodiment of the invention, an improved mud sill 1, for use with a generally horizontal baseplate 20 of a base of a vertical scaffolding member 22, is taught comprising a foot 2 with a transverse dimension measured in all directions that is substantially greater than each dimension in a parallel direction of the generally horizontal baseplate 20, and with a top surface that has an opening, a bottom surface, and an axial dimension, measured between the top surface 1a and the bottom surface 1b, that is perpendicular to the transverse dimension of the foot 2. The top surface 1a has an internal peripheral edge 4a defining the opening 4 and a recess 3 extends axially from the opening 4. The recess 3 is suitably sized to receive the baseplate 20 of the scaffolding member 22, so that the baseplate 20 can be disposed in the recess 3 of the foot 2 and the weight of the vertical scaffolding member 22 the mud sill 1. Preferably, a drain hole 5 extends from a lower surface 3a of the recess 3 to the bottom surface 1b of the foot 2.
A preferred opening 4 has a transverse dimension measured in all directions that is greater than each dimension in a parallel direction of the generally horizontal baseplate 20. Moreover, the recess 3 may comprise a first axial layer 7 defined by an upper surface having the internal peripheral edge 4a of the opening 4, a first lower surface 7b having a peripheral edge, and an inner wall 6 having an upper edge connected to the internal peripheral edge 4a of the opening 4 and a lower edge connected to the peripheral edge of the first lower surface 7b. The first axial layer 7 may also have a transverse shape corresponding to the transverse shape of the baseplate 20.
Additionally, the recess 3 may have a plurality of axial layers of varying transverse dimensions, so that the baseplate 20 can be inserted past the first axial layer 7 to a second axial layer 8 at a pre-determined axial depth and rotated in the second axial layer to secure the baseplate axially in said recess 3. Preferably, the second axial layer 8 has the shape of a circular disk.
In the preferred embodiment shown in
Moreover, the second axial layer 8 of the recess 3 may have at least one protuberance 8a in the path of a rotating baseplate 20 to restrict the rotation of the baseplate within the second axial layer 8 of the recess 3 to limit movement of the baseplate rotationally in said recess 3, as shown in
In one embodiment, as shown in
Referring to
Another preferred embodiment of the improved mud sill 1, for use with a generally horizontal baseplate 20 of a base of a vertical scaffolding member 22, comprises a foot 2, having a transverse dimension measured in all directions that is substantially greater than each dimension in a parallel direction of the generally horizontal baseplate 20, with a top surface that has an opening 4, a bottom surface 1b, and an axial dimension, measured between the top surface and the bottom surface, that is perpendicular to the transverse dimension of the foot 2. The top surface has an internal peripheral edge defining the opening 4. The opening has a transverse dimension measured in all directions that is greater than each dimension in a parallel direction of the generally horizontal baseplate 20 and a recess 3 extends axially from the opening with a drain hole 5 extends from a lower surface of the recess to the bottom surface of the foot 2. The recess is suitably sized to receive the baseplate 20 of the scaffolding member 22, so that the baseplate can be disposed in the recess 3 of the foot 2 and the weight of the vertical scaffolding member can be distributed over the transverse dimension of the foot of the mud sill 1.
Referring to
In one embodiment, as shown in
In another embodiment, as shown in
According to one embodiment of this important invention, an improved screw jack 24, as shown in
Preferably, a drain hole 5 extends from a lower surface 3a of the recess 3 to the bottom surface of the foot 2. As shown in
According to one aspect of the invention, the recess 3 comprises a first axial layer 7 defined by an upper surface 7a having the internal peripheral edge 4a of the opening 4, a first lower surface having a peripheral edge, and an inner wall having an upper edge connected to the internal peripheral edge of the opening 4 and a lower edge connected to the peripheral edge of the lower surface.
The mud sill 1 or foot 2 can be made of suitable materials, including wood, plastic or other hard material. It can be constructed in layers, as shown in
While this invention has been described in connection with the best mode presently contemplated by the inventor for carrying out his invention, the preferred embodiments described and shown are for purposes of illustration only, and are not to be construed as constituting any limitations of the invention. Modifications will be obvious to those skilled in the art, and all modifications that do not depart from the spirit of the invention are intended to be included within the scope of the appended claims. Those skilled in the art will appreciate that the conception upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
My invention resides not in any one of these features per se, but rather in the particular combinations of some or all of them herein disclosed and claimed and it is distinguished from the prior art in these particular combinations of some or all of its structures for the functions specified.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, including variations in size, materials, shape, form, function and manner of operation, assembly and use, and all equivalent relationships to those illustrated in the drawings and described in the specification, that would be deemed readily apparent and obvious to one skilled in the art, 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.
