The present invention relates to paper-based elongate structures suitable for use as lumber substitutes, articles of manufacture made thereof, kits of materials including such structures, and machines and methods for making the same.
The present applicant is the owner of U.S. Pat. No. 8,459,190 B2, which is hereby incorporated by reference in its entirety. Such patent discloses elongate structures, which can be fabricated from paper-based materials such as corrugated fiberboard, and which can be used for a variety of applications including, but not limited to, lumber substitutes in some applications (e.g., as pallet runners). Such elongate structures are extraordinarily strong, yet are lightweight and can be fabricated on-site on an as-needed basis by hand or, more preferably using machines such as disclosed in co-pending U.S. application Ser. No. 13/765,482 (see Pub. No. US 2013/0157832 A1), which is also hereby incorporated by reference in its entirety.
The present invention relates to paper-based elongate structures suitable for use as lumber substitutes, articles of manufacture made thereof, kits of materials including such structures, and machines and methods for making the same. Elongate structures according to the invention comprise a hollow outer portion formed of corrugated fiberboard sheet material and an accordion-folded inner support formed of corrugated fiberboard sheet material. The hollow outer portion has four outer surfaces that define a rectangle when viewed in cross-section transverse to a longitudinal axis of the elongate structure. The accordion-folded inner support is enclosed within the hollow outer portion. The inner support includes a plurality of first spaced-apart peaks that contact a first inner surface of the hollow outer portion and a plurality of second spaced-apart peaks that contact an opposing second inner surface of the hollow outer portion. In one embodiment, the hollow outer portion and the accordion-folded inner support are formed of separate and distinct pieces of corrugated fiberboard sheet material. In another embodiment, the hollow outer support and the accordion-folded inner support are integrally formed from one piece of corrugated fiberboard sheet material. In some embodiments, at least a portion of the first peaks are adhesively joined to the first inner surface and/or at least a portion of the second peaks are adhesively joined to the second inner surface. Preferably, the rectangle of the elongate structures according to the invention (when viewed in cross-section transverse to the longitudinal axis) has a thickness that is equivalent to minimum dressed dry dimension lumber having a nominal inch thickness of 2, 2½, 3, 3½, 4 or 4½, and a width that is equivalent to minimum dressed dry dimension lumber having a nominal inch width of 2, 2½, 3, 3½, 4, 4½, 5, 6, 8, 10, 12, 14 or 16, both as set forth in Table 3 of Voluntary Product Standard PS 20-15, American Softwood Lumber Standard, U.S. Department of Commerce, National Institute of Standards and Technology, effective April 2015. The accordion-folded inner support structure improves the beam strength, crush resistance and lateral strength of the elongate structure.
The foregoing and other features of the invention are hereinafter more fully described below, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the present invention may be employed.
With reference to the accompanying drawing figures, please note that:
With reference to
Preferably, the hollow outer support 30 and the accordion-folded inner support 40 are integrally formed from one piece of corrugated fiberboard sheet material (e.g., as shown in
The blank 100 can be folded by hand to create an elongate structure 10 according to the invention. However, it is more expedient to form the elongate structure 10 using a method and machine according to the invention. In one embodiment, the method of the invention comprises providing the substantially flat blank 100 formed of corrugated fiberboard that includes the plurality of creases 110a-1101 that define fold lines, folding the first portion 120 of the blank 100 on fold lines 110a-110h to form the accordion-folded inner support 40, and folding the second portion 130 of the blank 100 on fold lines 110i-1101 to form the hollow outer portion 30 such that the accordion-folded inner support 40 is enclosed within the hollow outer portion 30.
An adhesive (e.g., a fast-setting glue, double-sided adhesive tape, hot melt adhesives etc.) is preferably applied during fabrication such that at least a portion of the first peaks 60 are adhesively joined to the first inner surface 70 and/or at least a portion of the second peaks 80 are adhesively joined to the second inner surface 90. More preferably, an adhesive is applied at all points of contact between the corrugated fiberboard used to fabricate the elongate structure 10 including, but not limited to, both lap joints 140, one of which being where the accordion-folded inner support 40 contacts the hollow outer support 30 after the last crease 110l, and the other of which being where the inner support contacts 40 the opposing inner side of the hollow outer portion 30.
As noted above, the elongate structure 10 is preferably manufactured using a machine according to the invention. The machine includes a pair of opposing forming fixture blades 150, 160, which press against the blank 100 from opposing sides in the directions indicated by arrows 170, 180, respectively, on the creases in the first portion 120 of the blank 100 on fold lines 110a-110h to form the accordion-folded inner support 40. It will be appreciated that the forming fixture blades 150, 160 also move closer together as they press against the blank 100 in the direction indicated by arrows 170, 180. In the schematic illustration shown in
Adhesive is preferably applied to the peaks 60, 80 and the lap joint 140, either before or after the accordion-folded inner support 40 is formed by the machine. There are two ways of forming the hollow outer portion 30 such that it encloses the accordion-folded inner support 40. In a preferred embodiment, the machine includes a motor, which rotates the formed accordion-folded inner support 40 as the remaining second portion 130 of the blank 100 is folded around the accordion-folded inner support 40 to form the hollow outer portion 30. In an alternative embodiment, the machine includes a motor that moves the formed accordion-folded inner support 40 through a series of movements laterally and vertically within a forming guide, which bends the remaining second portion 130 of the blank 100 such that it folded around the accordion-folded inner support 40 to form the hollow outer portion 30. For example, with reference to
Although elongate structures according to the invention can be formed to have virtually any desired overall dimensions (length, thickness and width), elongate structures according to the invention preferably have the same dimensions as minimum dressed dry dimension lumber having a nominal inch thickness and nominal inch width as set forth in Table 3 of Voluntary Product Standard PS 20-15, American Softwood Lumber Standard (U.S. Department of Commerce, National Institute of Standards and Technology) effective April 2015 (hereinafter “Lumber Standard”), which is hereby incorporated by reference. Thus, the hollow outer portion has four outer surfaces that define a rectangle when viewed in cross-section transverse to a longitudinal axis of the elongate structure that has a thickness that is equivalent to minimum dressed dry dimension lumber having a nominal inch thickness of 2, 2½, 3, 3½, 4 or 4½ as set forth in in the Lumber Standard, and a width that is equivalent to minimum dressed dry dimension lumber having a nominal inch width of 2, 2½, 3, 3½, 4, 4½, 5, 6, 8, 10, 12, 14 or 16 as set forth in in the Lumbers Standard.
It should be noted that in
The properties of corrugated fiberboard are far different than a linear elastic material like a metal, so the strength of an elongate structure formed of folded and glued corrugated fiberboard is difficult to predict or model. However, applicant has observed that strong elongate structures can be obtained when the elongate structure exhibits a profile ratio of 3.37±20%. To calculate the profile ratio, one must first calculate the circumference of the cross-section of the elongate structure (CS), which is two times the actual height (H) plus two times the actual width (W), then calculate the area of the fiberboard blank (BA) in inches (as viewed from the edge of the blank parallel to the creases), and then divide the circumference of the elongate structure (CS) by the area of the blank (BA). The structural profile ratio for the embodiments shown in
Impact testing is accomplished by dropping the vertical rod 260 from its highest lifted point such that the impact bar 260 under the force of gravity accelerates and then impacts the elongate structure 10 at the mid-point between the two elevated stages 220. An elongate structure 10 is deemed to have sufficient strength if it remains straight after impact. Elongate structures according to
An elongate structure 10 is deemed to have sufficient resistance to deformation if it remains straight (i.e., does not bend) after supporting the weight 310 for a period of time of twenty-four hours. Elongate structures according to
As noted above, the elongate structures according to the invention are preferably formed of corrugated fiberboard material. The corrugated fiberboard material can optionally be coated or treated to affect certain properties of the elongated structure. For example, the corrugated material can be coated with a water-repellant treatment to improve water degradation resistance. The corrugated fiberboard material can be subjected to an ink-receptive treatment, which improves the ability of the elongated structures to be printed. The elongate structures can be formed from single plies of corrugated fiberboard material, or can be formed from multiple plies. Various thicknesses of corrugated fiberboard can also be used.
Elongate structures according to the invention can be formed in virtually any length. However, for expediency and convenience, the elongate structures are preferably formed into standard lengths (e.g., 1 foot, 18 inches, 24 inches, 36 inches, 48 inches, 72 inches and 96 inches). The elongate structures can be cut using power equipment and tools used to cut conventional dimensional lumber (e.g., circular saws, jigsaws, hand saws). The elongate structures can be mitered to form adjoining corners of any angle. They can also be cut using knives or other cutting instruments.
Elongate structures according to the invention can be joined to each other or to other materials such as panels of corrugated fiberboard using adhesives and fasteners.
Other shapes and types of gussets can be used. For example, gussets having the shape of a plus sign (“+”) can be used to join three or four elongate structures together at 90°. Gussets can be formed to join elongate structures together at angles other than 90°. Gussets can be made of several plies of corrugated fiberboard (or other material), and can be affixed to the elongate structures using adhesives and/or fasteners.
A variety of fasteners can be used to join elongate structures together with or without gussets. Suitable fasteners include nails, brads, staples, screws, and hook-and-loop fasteners (e.g. VELCRO). Washers (e.g., plastic washers) can also be used to widen the area of contact between the head of the fastener and the corrugated fiberboard adjacent to the hole of the shank(s) of the fastener. Particularly suitable fasteners are ribbed shank plastic rivets, which are widely available. Adhesives such as hot melt glue, cold glues, adhesive tapes etc. can be used alone or with fasteners to ensure a strong joint. Elongate structures can be joined to materials other than corrugated fiberboard including, for example, dimensional lumber and other building materials.
i show various exemplary articles and structures that can be formed using elongate structures according to the invention, gussets and other materials. For example,
Pallets formed of elongate structures according to the invention are strong, yet light in weight (at least ⅓ the weight of similar dimensioned pallets made of wood). They can be fabricated at the shipping site, and reused or recycled with other fiberboard materials at the shipping destination. The reduction in weight saves shipping weight, which reduces freight costs and fuel consumption.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and illustrative examples shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
Filing Document | Filing Date | Country | Kind |
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PCT/US15/57956 | 10/29/2015 | WO | 00 |
Number | Date | Country | |
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62072746 | Oct 2014 | US | |
62135794 | Mar 2015 | US | |
62206588 | Aug 2015 | US |