Fire escape – ladder – or scaffold – Platform
Reexamination Certificate
2000-07-11
2002-08-13
Chin-Shue, Alvin (Department: 3634)
Fire escape, ladder, or scaffold
Platform
C182S119000, C182S046000
Reexamination Certificate
active
06431316
ABSTRACT:
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
(Not Applicable)
BACKGROUND OF THE INVENTION
The present invention relates generally to scaffolding systems, and more particularly to a scaffold plank fabricated from a plastic material and optionally reinforced with steel.
As is well known in the building industry, scaffolding is virtually always employed during various facets of exterior and/or interior building construction or refurbishment. Known scaffolding systems typically comprise steel support frame structures which are selectively engageable to each other in a stacked fashion for achieving a desired overall height. In addition to the support frame structures, the scaffolding system includes a multiplicity of elongate scaffold planks, each of which is horizontally extensible between a respective pair of the support frame structures. The prior art scaffold planks are most typically fabricated from wood. Indeed, the use of wood for the prior art scaffold planks has been a long standing tradition in the building industry.
Though wood scaffold planks have been and continue to be generally suitable for use in scaffolding systems, the use of wood for the scaffolding planks gives rise to certain shortcomings and deficiencies which detract from their overall utility. More particularly, scaffold planks fabricated from wood are susceptible to splitting as well as to dry rot. Additionally, when exteriorly used scaffolding systems are subjected to a rain or thunder storm as often occurs, the resultant water soaking of the wood scaffold planks virtually doubles their weight as compared to when dry, thus substantially increasing the difficulty by which they are moved or otherwise manipulated. Such water soaking of the wood scaffold planks also often results in the warping or twisting thereof. As will be recognized, due to their susceptibility to splitting, dry rot and warping/twisting, the prior art wood scaffold planks have a reasonably limited life span, and require moderately frequent replacement.
Another drawback associated with the use of wood scaffold planks is the common occurrence of scaffold setters experiencing splinters in their hands when working with the same. Indeed, occurrences of splinters can reach a level of severity resulting in the initiation of a workers compensation claim. Moreover, because nails are also often used in conjunction with wood scaffold planks, workers are more susceptible to being injured by nails which are left therewithin.
A further problem associated with the use of wood scaffold planks is the relatively high cost thereof attributable to diminishing supplies of lumber. Indeed, ongoing extensive worldwide deforestation and the related environmental and ecological problems has, in addition to resulting in increases in the price of lumber, stimulated a movement to adopt lumber alternatives for purposes of contributing to the conservation and restoration of forests. These diminishing supplies of lumber also frequently give rise to delays in the delivery of lumber raw material to those mills which manufacture wood scaffold planks, thus resulting in periodic problems in meeting the supply demands of the building industry.
The present invention addresses these concerns by providing a scaffold plank which is manufactured or fabricated from a plastic material and may optionally be reinforced with a metallic material. As will be discussed below, the plastic scaffold plank of the present invention, though possessing the same level of structural integrity or rigidity as the prior art wood scaffold planks, does not have the same susceptibility to splitting, dry rot or warping/twisting. Additionally, the weight of the plastic scaffold plank of the present invention is the same whether wet or dry. The use of plastic for the scaffold planks of the present invention also eliminates occurrences of splinters, and substantially eliminates injuries potentially caused by nails left therein. Further, since the scaffold planks of the present invention may be fabricated from recycled/recyclable plastic material, they address the need of recycling used plastic into a useful product, in addition to satisfying the increasing desire in industry for lumber alternatives. These, and other features of the present invention will be described in more detail below.
BRIEF SUMMARY OF THE INVENTION
In accordance with a first embodiment of the present invention, there is provided a scaffold plank which has an elongate, generally rectangular configuration and includes a main body which defines opposed ends. Attached to respective ones of the opposed ends of the main body is a pair of identically configured end caps. The main body of the scaffold plank itself comprises top and bottom walls and an opposed pair of longitudinally extending sidewalls which are integrally connected to the top and bottom walls. Integrally connected to and extending perpendicularly between the top and bottom walls are multiple reinforcement webs which extend in generally parallel relation to each other, thus defining multiple compartments or cavities which extend longitudinally within the interior of the main body. Also formed on the top wall and extending longitudinally therealong within the interior of the main body are multiple ribs which, along with the top and bottom walls and reinforcement webs, collectively define multiple slots which are each adapted to accommodate a reinforcement bar. Both the main body and the end caps are preferably fabricated from a plastic material (e.g., virgin or recycled plastic), with the attachment of the end caps to the main body preferably being accomplished through the use of sonic welding, pins, snap fit, or an adhesive. Additionally, the main body is preferably fabricated through the use of an extrusion process, with the end caps each preferably being fabricated through the use of an injection molding process.
In accordance with a second embodiment of the present invention, there is provided a scaffold plank which includes a rectangularly configured main body having a top wall, an opposed pair of longitudinally extending sidewalls which are preferably integrally connected to the top wall, and an opposed pair of end walls which are preferably integrally connected to the top and sidewalls and define respective ones of the opposed ends of the scaffold plank. The main body of the scaffold plank of the second embodiment is formed to include multiple channel members which are integrally connected to the top wall and, together with the top wall alone or in combination with the sidewalls, collectively define multiple slots which are each sized and configured to accommodate a reinforcement bar. Also integrally connected to the top wall are multiple primary reinforcement webs which are disposed between and extend in generally parallel relation to adjacent pairs of the channel members. Integrally connected to and extending angularly between each of the primary reinforcement webs and the channel members of a corresponding pair are a plurality of secondary reinforcement webs which are also integrally connected to the top wall.
The scaffold plank of the second embodiment may further comprise a cover member which is attached to the main body through the use of, for example, sonic welding or an adhesive. Both the main body and the cover member are preferably fabricated from a plastic material (e.g., virgin or recycled plastic). Additionally, the main body and the cover member are each preferably fabricated via an injection molding, rotational molding, or vacuum forming process, with the reinforcement bars, if any, being pre-positioned within the mold and the plastic material thereafter being injection molded about the same.
REFERENCES:
patent: 1975262 (1934-10-01), Evans
patent: 4496029 (1985-01-01), Kuroda
patent: 4852691 (1989-08-01), Bruno
patent: 5596933 (1997-01-01), Knight
patent: 5882136 (1999-03-01), Pyritz
patent: 1148927 (1969-04-01), None
patent: 2234003 (1991-01-01), None
Chin-Shue Alvin
Stetina Brunda Garred & Brucker
LandOfFree
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