The present invention relates generally to first class lever devices, and more particularly, to a universal attachment assembly system and method comprising a pair of clamping levers, a tension delivery member, and a tension adjustment member, wherein the tensile pulling force delivered to each clamping lever is directionally changed, via the fulcrum, into a compressive force, thereby facilitating secure placement and seating of the universal attachment assembly in a selected position. This invention is particularly suited for, although not limited to, attaching covers over openings, anchoring intermediate supports between covers, and securing braces behind weak covers, such as, for exemplary purposes only, to attach shutters over windows and door openings, to anchor structural columns to brace garage doors, and to provide intermediate support for shutters during hurricanes. Hereinafter, one of the most severe and dramatic applications will be used to represent all applications—that of the protection of one's home at the approach of the hurricane; however although conveniently described in such a preferred use, the system and device of the present invention is suitable and could be utilized for securing cargo containers and/or any other suitably constructed, generally framed structure.
The down sides and obvious cost and damage due to hurricanes is common knowledge. The reader is referred to most all patents on the subject for this background and it will not be repeated herein.
Concrete is known and well documented in history as an excellent material in compression. However, in structural uses concrete has zero allowable strength in tension. Only metallic inserts, which create diagonal compression in the creation of a shear cone about the fastener, are attributed to producing tensile attachment. To exacerbate this problem, concrete is friable and subject to crumbling when exposed to cyclical compressive and tensile loading as by the turbulent winds of a hurricane. And yet, most buildings constructed close to ocean shores are concrete.
Thus, the problems are apparent with respect to available modes of attachment for protective barriers to be installed on such structures. How does one generate a resiliently soft but strong compressive force and eliminate the tensile forces as is required by the inherent nature of concrete? And further, how does one transfer this to the violently, fluctuating turbulent loads as generated by hurricane winds? And all the while, economics, ease of handling and speed of installation over a wide diversity of sites and shapes of openings must be provided. This is precisely the teaching of the present invention.
Tensile forces lead to expansion, wherein the length of a material increases in the direction of the pulling forces of the tension, and wherein volume remains constant, until the stress limit is reached and breakage occurs. Nails, bolts and anchors are structural members that are in direct tension during use. Compressive forces are opposing to tensile forces, and as such tend to compact materials. Thus, it is the exploitation of the inherent nature of concrete and its great compressive strength that enables the present invention to address and overcome the disadvantages in presently existing attachment assemblies.
The predominant direction of technology and investment is currently to create better inserts for concrete. That is, to try to pack tremendous resiliency in the small clearances between the concrete and the insert, in an effort to increase the tensile strength of the inserts to attempt to overcome the tensile limitations of concrete. All the while, these devices are making bigger scars on the face of buildings. The approach is generally accompanied by permanent mounting tracks or rails around the openings to further distract from the appearance of the home. (Ref. US2003/0134091 AL etc.) In addition to the aesthetic disadvantages, generally complicated installation is necessary.
Further, even with the realization of stress distribution and resultant increase in strength from such tracks or rails, installations of these critical devices can be prone to error as witnessed by the following recent example. It is no accident that after the landfall of the second tropical storm of 2003 in the USA, in Texas, one of the greatest costs of damage was attributed to failed inserts into concrete. Vibration loosened the inserts and the winds ripped off shutters, burst windows, and flooded the buildings with heavy rains. And this was only a class 1 hurricane.
Even if the insert stays in, a tremendous disadvantage with inserts is that threaded metal female inserts or threaded studs are left permanently mounted outdoors exposed to salt spray, rain, and dusty environments, or, potentially worse, covered with paint. Even stainless steel in this application is subject to galling and cross threading, and galvanized steel is no better. None of these disadvantages and concerns is comforting when a hurricane is rapidly approaching.
Recognizing the limitations of tensile strength dependent systems, U.S. Pat. No. 5,579,604 to Holung et al. describes the approach of mounting a compressive device inside an opening and using compression to secure a covering thereover. Even still, the compressive device therein described is disadvantageous in view of the present invention, wherein the Holung et al device requires a complicated gear/lock mechanism for delivery and maintenance of the compressive force.
Further, a great problem with all previous related devices is that compressive members over large spans are subject to buckling or collapse due to bending. Therefore, compressive members must be laterally braced and or increased in mass and cross-section to prevent buckling. This results in more weight and complexity, and therefore increased cost and potential for failure. Moreover, greater weight and complexity, in turn, increases the difficultly and time of installation.
One final problem in installing attachment assemblies to buildings relates to the lack of detents or shallow holes in the sidewall of a building's openings. Concrete block construction is almost universally finished with stucco. Initial tests on the present invention revealed that most stuccoes crumble under compression and shears off the surface. This leaves sand and chips of debris, which act as a lubricant similar to gravel on a curve in a road. It is thus necessary to at least penetrate the finish layer and expose solid aggregate to rest the compressive member on. However, additionally, the addition of a slight ridge for the compressive foot to rise over assures that this will not be the weakest link in the design.
The present invention relies on the rigidity of the shutter or covering to carry the compressive force. The limiting requirement of a shutter is not its strength, but the deflection required by codes. Therefore the specific requirements of each type of material, be it plywood, corrugated steel, plastic or aluminum, vary and the allowable spans must be evaluated separately. In any event, such panels are already designed for stiffness and a small limitation of span or increase of metal gauge is the only consequence, depending on the class of hurricane and wind speed being assumed for the geographic area.
A final point regarding inserts and anchors. They require full penetration of the concrete block's web and therefore frequently introduce leakage paths for water to travel to the core of the block. Disadvantageous effects on indoor air quality and increased mold potential are only now beginning to be recognized and addressed. However, the small shallow dents as required by the present invention are only approximately ⅓ to 1/2 of the depth of the wall of the block, thus avoiding the creation of such pathways. When painted like the wall and located on the side of the wall rather than the face of the wall, such installation dents are virtually invisible with no concern of corrosion, thread damage, or contamination of interior air quality.
Therefore, it is readily apparent that there is a need for a system and method for attachment assembly, wherein the incorporation of a lever ensures that tensile forces are minimized and compressive forces are maximized, wherein permanent installation of base members is not necessary, and wherein simplicity of components facilitates quick and easy installation and removal and cost-effectiveness, thereby avoiding the above-discussed disadvantages.
Briefly described, in a preferred embodiment, the present invention overcomes the above-mentioned disadvantages and meets the recognized need for such a device by providing an attachment assembly for the connection and installation of covers of all types over openings of all types without defacing the surface of the openings.
According to its major aspects and broadly stated, in its preferred form, the present invention is a universal attachment assembly for clamping and bracing covers over openings, wherein the simplicity of design and operation of the unique lever system, the economy of the assembly components, the realized resistance to vibration, and speed of installation and removal are but a few of the beneficial characteristics of this invention.
More specifically, the device of the present invention in its preferred form is an attachment assembly comprising a series of force-generating and directing components. First, a tensile latching force is generated, preferably by an inexpensive, commercially available ratcheting device. This tensile force is transmitted, either across the width of a generally planar cover or along the length of a structural column, by inexpensive, lightweight straps. Because the tensile generating device is located between the fulcrum points of the cover panel or reinforcing column, the materials required to transfer the forces are only a very light, flexible, and inexpensive strap. Only then are the rigid and strong levers necessary to operate in cooperation with the cover to result in compression against the structure of the opening. Thus, the mounting of the attachment assembly is accomplished by simply defining throughholes at the margin of the panel and inserting levers to convert tensile forces outboard of the shutter to compressive forces bearing on the concrete inboard of shutter. The lever fulcrums are positioned proximate the throughhole of the shutter or cover, with a pulling force from the tensile generating device transferred via the straps to the lever and converted thereby to a compressive force delivered to structure bearing the opening to be covered.
The geometry of the various load points of the lever and the location of the fulcrum generate an acute angle of the force vector relative to the panel. This clamps a portion of concrete between the lever and the shutters and snugs the shutter or panel against the outside face of the opening. On thin metal or plastic panels, a grommet may be utilized about the fulcrum hole to relieve stress concentrations and potential deformation of the panel material by uniformly distributing the point load over a larger area of the panel.
Further, the invention efficiently uses the inherent elasticity of the straps to provide constant compression of the levers against the concrete regardless of the turbulent buffeting of the winds. By initially preloading the straps in tension, a large compression force is superimposed over the cyclical loads. Therefore the resultant load is a varying compressive load. This totally eliminates the need for the unattractive inserts and their frequent failure. This concept is well proven by the use of this type of apparatus in cargo clamps on exposed trucks or trailers.
The present invention may also be used, without modification, in a closely related application of the ratcheting strap type tensioning system. This additional device is a structural column to be used as an intermediate support for spanning of long architectural openings by shutters or other coverings. Such columns may also be utilized to brace garage doors. This application, in its preferred configuration, consists of structural 2″ thick lumber, a plurality of clamp assemblies and metallic termination angles. Unlike the throughholes of the planar coverings discussed hereinabove, the columnar structural reinforcement utilizes the termination angles to provide a narrow fulcrum point for the levers. Such angles also function to convert what could potentially be an instable bending connection into a stable and strong shear connection. This columnar design provides the same advantages as described in the planar covering or shutter.
Thus, a feature and advantage of the present invention is its ability to exploit a first class lever design to overcome tensile strength deficiencies, while harnessing compressive strength benefits in typical concrete constructions in order to facilitate attachment thereto.
Another feature and advantage of the present invention is its ability to directionally change and convert the tensile pulling force delivered to each clamping lever into a compressive force, thereby facilitating secure placement and seating of the universal attachment assembly in a selected position.
Another feature and advantage of the present invention its ability to attach generally planar coverings over openings.
Yet another feature and advantage of the present invention is its ability to anchor intermediate supports between coverings.
Still another feature and advantage of the present invention is its ability to secure braces behind weak coverings.
Yet still another feature and advantage of the present invention is its ability to attach shutters over windows and door openings.
Still yet another feature and advantage of the present invention is its ability to anchor structural columns to brace garage doors.
Further yet another feature and advantage of the present invention is its ability to provide intermediate support for shutters during hurricanes.
Yet another feature and advantage of the present invention is its ability to facilitate attachment to concrete without the installation of metallic inserts.
Still another feature and advantage of the present invention is its ability to generate a resiliently soft but strong compressive force and eliminate the tensile forces as is required by the inherent nature of concrete.
Further still another feature and advantage of the present invention is its ability to provide an attachment assembly with a system and method that is economical, easy to handle, and speedy to install over a wide diversity of sites and shapes of openings.
Yet still another feature and advantage of the present invention is its ability to eliminate the need for scarring on the face of buildings.
Further yet another feature and advantage of the present invention is its ability to virtually eliminate the risk of vibrational failure.
And still another feature and advantage of the present invention is its ability to eliminate negative impact from exposure to salt spray, rain, dust, and/or paint.
A further feature and advantage of the present invention is its ability to rely on the rigidity of the cover, or structural column to transfer, via the lever fulcrum, the compressive force.
Still a further feature and advantage of the present invention is its ability to eliminate the need for full penetration of the concrete block's web, thereby avoiding the introduction of leakage paths and resultant disadvantageous effects on indoor air quality via increased mold potential.
Yet still another feature and advantage of the present invention is its ability to rely on compression delivery points that are aesthetically pleasing and virtually undetectable, thus facilitating the placement of covers of all types of openings without defacing the surface thereof.
Yet another feature and advantage of the present invention is its ability to be disassembled and transported for reassembly at a subsequent location.
Still yet another feature and advantage of the present invention is its ability to define a lightweight yet structurally sound attachment assembly.
Yet another feature and advantage of the present invention is its ability to provide a protective covering assembly that is capable of assembly and use without necessitating tools.
Still another feature and advantage of the present invention is its ability to provide a protective covering assembly that is capable of secure assembly and safe use without necessitating the incorporation of screws or fastening pins.
These and other features and advantages of the invention will become more apparent to one skilled in the art from the following description and claims when read in light of the accompanying drawings.
The present invention will be better understood by reading the Detailed Description of the Preferred and Alternate Embodiments with reference to the accompanying drawing figures, in which like reference numerals denote similar structure and refer to like elements throughout, and in which:
In describing the preferred and alternate embodiments of the present invention, as illustrated in the figures and/or described herein, specific terminology is employed for the sake of clarity. The invention, however, is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish similar functions.
First, in order to clearly distinguish the benefits of the present invention, it may be instructive to describe at least one known prior art attachment assembly, as depicted in
By contrast, referring to
Second end 12 of clamping lever 10 is preferably compressive force delivery point 104, bearing from inflection 106, a concavity opposing that of fulcrum inflection point 13. In use, second end 12 is preferably passed through fulcrum hole 23 of covering or shutter S, toward the interior of the structure opening, and preferably brought to bear on retainer hole 26, preferably defined into an opening frame, F, such as, for exemplary purposes only, a window casement, sill, door jam, or the like.
It will be noted that for maximum stability to exist in the loaded lever 10, the load point of the fulcrum hole 23 is preferably located to the right of a line of centers through the load points 17 of the two ends of lever 10, as shown in
In the preferred embodiment, first strap 22a of universal attachment assembly 20 connects at first end 108 to first end 11 of first lever 10b. Second end 110 of strap 22a is preferably free to be wrapped about the drum (not shown) of ratcheting device 21. Similarly, second strap 22b is securedly attached at its first end 112 to first end 11 of second lever 10b, and at its second end 114 to the body of ratcheting device 21. It is this unique combination of first class levers 10a and 10b, ratcheting device 21, and tensioning assembly 100 that defines the preferred universal attachment assembly 20 of the present invention, thereby enabling structural protection and/or reinforcement via directional conversion of tensile forces to compressive forces.
Termination angle 32 is preferably L-shaped bracket 116, securely fastened to each end of structural column 31. Preferably, the means of attachment for L-shaped bracket 116 to structural column 31 are typical fasteners 36, such as, without limitation, screws or bolts. Although such a configuration is preferred, integral formation, such as with a composite or steel structural column, could also be utilized. Alignment holes 34 defined in L-shaped bracket 116 provide guides and shear connection to the frame being supported, such as to a garage floor and roof structure, wherein alignment holes 34 are functionally related to retainer holes 26 of the panel retention embodiment described hereinabove, wherein compressive force delivery point 104 of lever 10 extends therethrough. Alignment holes 24 thus provide guidance and retention of lever motion.
It should be noted that supplemental structures may be necessary to facilitate attachment of structural column 31 to garage ceilings, depending on site-specific conditions. That is, the length of column assembly 30 should be adjusted for a slip fit or preferably a light force fit between faces of the openings in which column assembly 30 is installed in order to provide a sheer connection. A pair of slotted holes for receiving fasteners 36 may be utilized to facilitate this adjustment.
The preferred conformation and use in securing a protective covering over an opening is depicted in
In another preferred conformation and use for attachment assembly 20, structural bracing of large span openings may be accomplished, as is depicted in
Having thus described exemplary embodiments of the present invention, it should be noted by those skilled in the art that the within disclosures are exemplary only, and that various other alternatives, adaptations, and modifications may be made within the scope of the present invention. Accordingly, the present invention is not limited to the specific embodiments illustrated herein, but is limited only by the following claims.
This application claims priority to, all benefit of and is a Continuation-in-Part of co-pending U.S. Non-Provisional Utility patent application Ser. No. 10/698,085, filed Nov. 3, 2003, entitled “Universal Attachment Assembly for Clamping and Bracing Covers over Openings.”
Number | Date | Country | |
---|---|---|---|
Parent | 10698085 | Nov 2003 | US |
Child | 11448288 | Jun 2006 | US |