Referring now to
Blankets 18, 18a, 18b, 18c, 18d, 18e, 18f, 18g, and 18h of insulative material are individually placed in gaps or cavities defined between adjacent purlin beams 14 through 14g and in cavities between the eave struts 16 and 16a and the purlin beams 14 through 14g, respectively. In
Rigid roofing material such as metal decking 20 may then attached on top of the second layer of insulative blankets 18i and 18j. Only one section of metal decking 20 is shown. It will be understood however, that additional sections of metal decking 20 may be laid across the entire metal roof structure 10. It is generally customary to construct or finish the roof along the length of the structure from one endwall to an opposite endwall (i.e., in the direction of arrow 21), rather than from eave strut 16 to eave strut 16a. The workers assembling the roof structure 10 may stand on a previously laid section of the roof structure 10 while constructing an adjacent or next section. Alternatively, other assembly techniques may be used.
Various methods have been used to support the first layer of insulative blankets 18 through 18h. A known “banded liner system” is shown at 21 in
The illustrated banded liner system 21 includes mounting straps or banding that may be attached to the rafter beams 12 and 12a and the eave struts 16 and 16a. The banding may be arranged in a network or lattice structure. The banding may include first or longitudinal parallel banding strips 22 through 22b extending substantially parallel to the purlin beams 14 through 14g and second or transverse parallel banding strips 24 and 24b extending substantially transverse to the purlin beams 14 through 14g. Opposite distal ends of the parallel banding strips 22 through 22b are fixed to the upwardly facing surfaces of the rafter beams 12 and 12a. The opposite distal ends of the transverse banding strips 24 and 24b are similarly fixed to the downwardly facing surfaces of the eave struts 16 and 16a. It will be understood that only a portion of the parallel banding strips 22 through 22b and the transverse banding strips 24 and 24b are shown to allow other components of the metal roof structure 10 to be visible. However, a typical metal roof structure 10 may include parallel and transverse banding strips along the full perimeter defined by the rafter beams 12 and 12a and the eave struts 16 and 16a. In the illustrated embodiment, the parallel banding strips 22 through 22b and the transverse banding strips 24 and 24b are formed from steel. Alternatively, the parallel banding strips 22 through 22b and the transverse banding strips 24 and 24b may be formed from any other desired material, such as, aluminum, polypropylene, polyester, and other metal and non-metal material.
After the banding has been installed, a support sheet 26 may then be placed, typically by unfolding a pre-folded support sheet 26, onto the parallel banding strips 22 through 22b and the transverse banding strips 24 and 24b. At the intersection of each purlin beam 14 through 14g and the rafter beams 12 and 12a, the support sheet 26 may be notched to fit around the purlin beams 14 through 14g. In the illustrated embodiment, the support sheet 26 does not extend between the purlin beams 14 through 14g and the rafter beams 12 and 12a. The support sheet 26 may have a width extending the distance between the rafter beams 12 and 12a and a length extending the distance between the eave struts 16 and 16a. Typically, the support sheet 26 is made of polyethylene film, but the support sheet 26 may be formed from any other suitable material. Alternatively, the support sheet 26 may be made from any suitable material having sufficient tensile strength, tear strength, burst strength, and elongation to retain a four hundred (400) pound (181.5 kg) object dropped onto the banded liner system from a height of forty-two (42) inches (1.1 meters) above the support sheet 26.
After the support sheet 26 has been laid across the banding 22 through 22b and 24 through 24b, the support sheet 26 is fixed to the downwardly facing surfaces of the eave struts 16 and 16a and to the upwardly facing surfaces of the rafter beams 12 and 12a, similar to the banding. Also, the transverse banding strips 24 through 24b and the support sheet 26 may be fixed to the downwardly facing surfaces of the purlin beams 14 through 14g. Each connection of the support sheet 26 to one of the rafter beams 12 and 12a, to one of the eave struts 16 and 16a, and to one of the purlin beams 14 through 14g may be designated as an anchor point. After these connections are made, insulation cavities are defined between adjacent purlin beams 14 through 14g and further defined between the eave struts 16 and 16a and the purlin beams 14 through 14g, respectively. The blankets 18 through 18h may then be laid in place.
The above notwithstanding, there remains a need in the art for an improved fall protection for workers assembling the roof, as well as for other people having a need to be on the roof. To provide fall protection, the banded liner system should be configured to withstand an impact under pre-defined testing conditions. Specifically, the banded liner system must retain a four hundred (400) pound (181.5 kg) object dropped onto the banded liner system from a height of forty-two (42) inches (1.1 meters) above the walking working roof surface, typically the roof panel 20. This requirement is to ensure a worker assembling the roof will not fall through the support sheet 26 if the worker falls from the walking working roof surface 20.
The present application describes various embodiments of a novel roof structure of a building. The building has a pair of rafter beams and a pair of eave struts. The eave struts extend between, and are connected to the rafter beams. The roof structure further includes a plurality of first banding strips. The first banding strips have opposite distal ends extending between and connected to the rafter beams. A plurality of second banding strips has opposite distal ends extending between and connected to the eave struts. A support sheet is supported on the first and second banding strips, and a shock absorbing member is attached between the support sheet and one of the rafter beams or the eave struts.
Another embodiment of the novel a roof structure of a building is disclosed. The roof structure of the building has first and second rafter beams and an intermediate rafter beam between the first and second rafter beams. A first pair of eave struts extends between and is connected to the first and the intermediate rafter beams and defines a first bay. A second pair of eave struts extends between and is connected to the second and the intermediate rafter beams and defines a second bay. The novel banded liner system includes a plurality of first banding strips having opposite distal ends extending between and connected to the rafter beams in each bay. A plurality of second banding strips has opposite distal ends extending between and connected to the eave struts in each bay. A first support sheet is supported on the first and second banding strips in the first bay, and a second support sheet is supported on the first and second banding strips in the second bay. The first and the second support sheets are attached at a seam, which defines a shock absorbing joint.
An additional embodiment of the novel roof structure of a building is also disclosed, wherein the roof structure has a pair of rafter beams and a pair of eave struts extending between and connected to the rafter beams. A plurality of first banding strips has opposite distal ends extending between and connected to the rafter beams. A plurality of second banding strips has opposite distal ends extending between and connected to the eave struts. A primary support sheet is supported on the first and second banding strips, and a second support sheet is positioned on top of the primary support sheet. Outer peripheral edges of the primary support sheet are attached to each of the pair of rafter beams and the pair of eave struts, and an outer peripheral edge of the second support sheet is attached to one of (a) the pair of rafter beams and (b) the pair of eave struts.
A complete appreciation of the invention and the many embodiments thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
The present invention will now be described with occasional reference to the specific embodiments of the invention. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth as used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless otherwise indicated, the numerical properties set forth in the specification and claims are approximations that may vary depending on the desired properties sought to be obtained in embodiments of the present invention. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from error found in their respective measurements.
A deficiency in current and previous banded liner systems has been observed. Specifically, it has been observed that the support sheets in known banded liner systems are more likely to allow an object to pass to the ground when the object impacts the banded liner system proximate to the edges of the bay. The object may pass through a tear in the support sheet or pass between the support sheet and an edge of the bay. It is believed that when an object impacts the banded liner system proximate to the center of the bay, the load can be distributed more evenly over a greater number of anchor points. It is also believed that when the object impacts proximate to the center of the bay the support sheet itself can more readily deform, elastically or plastically, and thereby reduce the likelihood of tearing. Thus, when the object impacts proximate to the edges of the bay, a majority of the load is borne by fewer anchor points and the length or area over which the support sheet can deform without tearing is limited.
Various embodiments of an improved banded liner system with a shock absorber for the edges of the bay are described below. These embodiments are described in connection with the metal roof structure 10 set forth above. Alternative embodiments of the invention may also be practiced with forms of metal roofs other than the metal roof structure 10 described in this specification.
Referring now to
The first embodiment of the banded liner system 60 includes the support sheet 26. The support sheet 26 may be made of any suitable material, such as polyethylene film. Alternatively, the support sheet 26 may be made from any suitable material having sufficient tensile strength, tear strength, burst strength, and elongation to retain a four hundred (400) pound (181.5 kg) object dropped onto the banded liner system from a height of forty-two (42) inches (1.1 meters) above the support sheet 26.
As shown in
The first embodiment of the banded liner system 60 further includes a plurality of the parallel banding strips, only three of which are shown at 22, 22a, and 22b, and a plurality of the transverse banding strips, only six of which are shown at 24, 24a, 24b, 24c, 24d, and 24e. The parallel banding strips 22, 22a, and 22b may be attached to the upper surface 12S of the rafter beam 12 by any desired means, such as with fasteners, schematically illustrated at 23. The fastener may be any suitable fastener such as threaded fasteners, rivets, and the like. The transverse banding strips 24 through 24e may be attached to the lower surface (not shown) of the eave strut 16 by any desired means, such as with the fasteners 23 (not shown in
The support sheet 26 may be attached to the metal roof structure 10 by a plurality of shock absorbing members. In the illustrated embodiment, the shock absorbing member is a spring, shown schematically at 32. The springs 32 extend between the first connecting apertures 35 formed in the mounting members 34 and 36 and the second connecting apertures 37 formed in the reinforced edges 28 and 30. The springs 32 may be any desired extension spring. Alternatively, other shock-absorbing structures may be used in lieu of the springs 32, such as flexible fabric and other resilient members, such as a rubber member. It will be understood that the mounting members 34 and 36 are not required, and the springs 32 may be connected directly to the rafter beam 12 and the eave strut 16 through connecting apertures (not shown) formed in the rafter beam 12 and the eave strut 16.
As shown in
Referring now to
The illustrated banded liner system 70 includes a first or primary support sheet 27, and a secondary support sheet 40. In the illustrated embodiment, the primary support sheet 27 is formed from the same material as the support sheet 26. As shown in
The edge reinforcement member 44 may be any substantially rigid member such as a solid strip or a tube. In the illustrated embodiment, the edge reinforcement member 44 is formed from metal, such as sheet metal. Alternatively, the edge reinforcement member 44 may be formed from any other desired material, such as wood and plastic. Once wrapped, folded, or rolled around the edge reinforcement member 44, the peripheral edges of the primary support sheet 27 and the secondary support sheet 40 define a reinforced perimeter zone 74P. The perimeter zone 74P may be attached to the upper surface 12S of the rafter beam 12 by any desired means, such as with fasteners 72. The fasteners 72 may be any suitable fastener such as threaded fasteners, rivets, and the like. An inwardly facing edge 43 of the secondary support sheet 40 extends inwardly toward the bay 8. In the illustrated embodiment, the portion of the secondary support sheet 40 between the perimeter zone 74P and the inwardly facing edge 43 rests upon, but is not attached or bonded to, the primary support sheet 27.
Referring now to
Referring now to
The illustrated banded liner system 80 includes the support sheet 26. As shown in
Once wrapped or folded around the edge reinforcement member 44, the edge reinforcement member 44 and the wrapped portion of the support sheet 26 define a reinforced perimeter zone 84P. The perimeter zone 84P may be attached to the upper surface 12S of the rafter beam 12 by any desired means, such as with the fasteners 72. An inwardly facing edge 86 of the second support sheet portion 82B extends inwardly toward the bay 8. In the illustrated embodiment, the second support sheet portion 82B rests upon, but is not attached or bonded to, the first support sheet portion 82A.
Referring now to
If desired, the first support sheet portion 82A and the second support sheet portion 82B may be formed from different materials and bonded together such as by sewing. For example, the second support sheet portion 82B may be formed from a material that is more elastic than the first support sheet portion 82A. Additionally, the first support sheet portion 82A may be formed from a material that is stronger than the second support sheet portion 82B, and therefore able to absorb most of the force of a falling object. The second support sheet portion 82B, on its own, may not be capable of withstanding the force of an impact from a falling object. The second support sheet portion 82B may however, be capable of stretching without tearing to a point at which the first support sheet portion 82A has stabilized after the impact of the falling object. Thus, first support sheet portion 82A may tear beyond a desired amount while the second support sheet portion 82B remains un-torn, or only slightly torn. Examples of possible materials for the second support sheet portion 82B include the material used to form Glad FORCEFLEX® trash bags, flexible polyethylene film such as VISQUEEN brand film, or elastic netting. Such a choice of materials ensures that the impact of a falling object may be absorbed and, at the same time, ensures that an unacceptable tear will remain covered by the second support sheet portion 82B.
Referring now to
In
The support sheet assembly 29 provides an advantageous shock absorbing capability to the banded liner system 90. Because neither the seam 92 between the first and second support sheets 26 and 26a, nor the first and second support sheets 26 and 26a are attached to the upper surface 12S of the rafter beam 12, both sheets 26 and 26 may move upon impact from a falling object. For example, the force of impact of a falling object on the first support sheet 26 will urge the first support sheet 26 downwardly as the second support sheet 26a is pulled toward the first support sheet 26 and the point of impact. As a result, a distance over which either support sheet 26 or 26a may elongate under impact loading from a falling object is increased relative to a support sheet fixedly attached between two rafter beams 12. Thus, the support sheet assembly 29 is configured to act as a shock absorber. For example, the force of impact of a falling object on the first support sheet 26 will urge the first support sheet 26 downwardly as the second support sheet 26a is pulled toward the first support sheet 26 and the point of impact. The seam 92 may be formed by any desired means such as with an adhesive. Alternatively, the seam 92 may be formed by welding.
Referring now to
Referring now to
The illustrated banded liner system 110 includes the support sheet 26. As shown in
The pleated portion 48 may include a stitched seam 116, wherein the pleats 48P of the pleated portion 48 are sewn together with thread of a predetermined strength. The strength of the thread defining the stitched seam 116 may be selected such that upon impact of an object, one or more pleats 48P separates from the remaining pleats 48P, allowing the pleat 48P to straighten and the support sheet 26 to extend inwardly toward the bay 8. The strength of the thread may be selected such that upon impact of a falling object, all of the pleats 48P separate from one another and straighten. The pleats 48P may be joined by threads of different strength. For example, the thread joining a first and second of the pleats 48P may have a strength lower than the thread joining a third and a fourth of the pleats 48P. In operation, the force of the impact of a falling object may cause the first and second pleats 48P to separate and straighten initially and, only if the impact loading is not yet absorbed, will the third and fourth pleats then separate and straighten.
It will be understood that the thread described above defines controlled weakness points in the support sheet 26. Alternatively, adhesive, clips, or other suitable mechanisms may be used in lieu of thread to bind and maintain the pleats 48P together. It will be further understood that other forms of controlled weakness points may be applied in alternative embodiments of the invention. For example, the support sheet 26 may be formed with slits that open in response to the impact of the object.
It will be appreciated that the several embodiments illustrated in
The embodiments of the embodiment of the banded liner systems 60, 70, 80, 90, 100, and 110 have each been described as including the parallel banding strips 22, 22a, and 22b, and the transverse banding strips 24, 24a, 24b, 24c, 24d, and 24e, such as shown in
The present invention should not be considered limited to the specific examples described herein, but rather should be understood to cover all aspects of the invention. Various modifications, equivalent processes, as well as numerous structures and devices to which the present invention may be applicable will be readily apparent to those of skill in the art. Those skilled in the art will understand that various changes may be made without departing from the scope of the invention, which is not to be considered limited to what is described in the specification.
This application claims the benefit of U.S. Provisional Application No. 61/184,112 filed Jun. 4, 2009.
Number | Date | Country | |
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61184112 | Jun 2009 | US |