CA1139518A - Structural beam - Google Patents
Structural beamInfo
- Publication number
- CA1139518A CA1139518A CA000354748A CA354748A CA1139518A CA 1139518 A CA1139518 A CA 1139518A CA 000354748 A CA000354748 A CA 000354748A CA 354748 A CA354748 A CA 354748A CA 1139518 A CA1139518 A CA 1139518A
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- CA
- Canada
- Prior art keywords
- panels
- halves
- panel
- flange
- chord member
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Abstract
ABSTRACT
A wooden structural beam composed of two opposi-tely shaped halves joined together to form the web portion, and the envelope, of the flange portion of the beam. Each beam half is molded from very thin wooden laminations bonded together and shaped to define a flat, vertical central panel, with diagonal panels extending upwardly and downwardly from the upper and lower edge portions of the central panel and trans-versely outwardly in a direction opposite the vertical line of symmetry of the beam. Each beam half also includes vertically disposed flange panels which extend upwardly and downwardly from their corresponding diagonal panels to lie in a plane parallel to, and transversely offset from, the plane of the central panel. The upper flange panels of the two beam halves define an upwardly open trough for snugly receiving a rectangularly shaped chord member therebetween. Correspondingly, the lower flange panels of the two beam halves define a downwardly open trough for snugly receiving a rectangularly shaped lower chord member therebetween. Constructed in this manner, the beam is pleasing enough in appearance to be left exposed to the interior of a dwelling, office or similar structure.
A wooden structural beam composed of two opposi-tely shaped halves joined together to form the web portion, and the envelope, of the flange portion of the beam. Each beam half is molded from very thin wooden laminations bonded together and shaped to define a flat, vertical central panel, with diagonal panels extending upwardly and downwardly from the upper and lower edge portions of the central panel and trans-versely outwardly in a direction opposite the vertical line of symmetry of the beam. Each beam half also includes vertically disposed flange panels which extend upwardly and downwardly from their corresponding diagonal panels to lie in a plane parallel to, and transversely offset from, the plane of the central panel. The upper flange panels of the two beam halves define an upwardly open trough for snugly receiving a rectangularly shaped chord member therebetween. Correspondingly, the lower flange panels of the two beam halves define a downwardly open trough for snugly receiving a rectangularly shaped lower chord member therebetween. Constructed in this manner, the beam is pleasing enough in appearance to be left exposed to the interior of a dwelling, office or similar structure.
Description
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, STRUCTURAL BEAM
DESCRIPTION
-Technical Field ' -The present invention relakes to wooden structural components, and in particular to a new structural beam member constructed from very thin sheets of wood material laminated together and molded into the shape ; of an I-beam.
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Background Art ; ~ In the past, various types of structural beams have been constructed from flat wooden members glued or otherwise bonded together to form I-~eams of different cross-sectional shapes. In one known type of wooden I-beam, the web portion is formed from multiple layers of flat wooden material bonded together in face-to-face relationship. The;lndividual flanges of the beam are also formed from flat sheets of wood bonded toyether \ and then attached transversely to the upper and lower edges of the web portion. In one example of this type of beam construction, as disclosed by Sahlberg, U.S. Patent 2,230,62fl, the w~b portion extends the full depth of the beam so that each flange is composed of two individual sections glued or otherwise attached to the opposite~sides~of the web upper and lower edges.
In another example, as disclosed by Knight, U.S.
Patent 1,377,891, the upper edge of the web engages , . . , , . i .- . . . .
.... . . . .. . . . . .
- within a longitudinal groove formed in the underside ; of the upper flange and the lower edge of the web engages within a lon~itudinal formed in the upper side of the lower flange. This construction is possibly effective in preventing the flange from failing when the beam is subjected to a sharp vertical load, but I
will no~ prevent fracture of the flanges through their grooves when the beam is subjected to'a horizontal impact load, such as encountered during an earthquake.
A further example of this particular type of beam construction is disclosed in U.S. Patent 4,074,498 to ~eller et al, wherein the upper and lower edges of the sheets of wooden material composing the web portion of the beam are staggered relative to each other to form tongues. These tongues are receivable within individual longitudinal grooves formed in the underside of the upper flange and the upper side of the lower flange.
In ano~her type of wooden I-beam, the web portion is formed from multiple layers of thin wooden slats with the slats of adjacent layers bonded in ': , !
face-to-face contact with each other. The flange portions of the beam are built up by placing elongate, rather narrow strips of wood on opposite sides of the web member so that the strips are disposed parallel to the plane of the web. Although this particular type of construction enables the beam to be assembled from narrow leng~hs of wood, assembling the web with these componen~s involves a slow, time-consuming ~operation. Examples of this general type of wooden I-beam construction wherein the slats of one web layer , ;
, STRUCTURAL BEAM
DESCRIPTION
-Technical Field ' -The present invention relakes to wooden structural components, and in particular to a new structural beam member constructed from very thin sheets of wood material laminated together and molded into the shape ; of an I-beam.
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Background Art ; ~ In the past, various types of structural beams have been constructed from flat wooden members glued or otherwise bonded together to form I-~eams of different cross-sectional shapes. In one known type of wooden I-beam, the web portion is formed from multiple layers of flat wooden material bonded together in face-to-face relationship. The;lndividual flanges of the beam are also formed from flat sheets of wood bonded toyether \ and then attached transversely to the upper and lower edges of the web portion. In one example of this type of beam construction, as disclosed by Sahlberg, U.S. Patent 2,230,62fl, the w~b portion extends the full depth of the beam so that each flange is composed of two individual sections glued or otherwise attached to the opposite~sides~of the web upper and lower edges.
In another example, as disclosed by Knight, U.S.
Patent 1,377,891, the upper edge of the web engages , . . , , . i .- . . . .
.... . . . .. . . . . .
- within a longitudinal groove formed in the underside ; of the upper flange and the lower edge of the web engages within a lon~itudinal formed in the upper side of the lower flange. This construction is possibly effective in preventing the flange from failing when the beam is subjected to a sharp vertical load, but I
will no~ prevent fracture of the flanges through their grooves when the beam is subjected to'a horizontal impact load, such as encountered during an earthquake.
A further example of this particular type of beam construction is disclosed in U.S. Patent 4,074,498 to ~eller et al, wherein the upper and lower edges of the sheets of wooden material composing the web portion of the beam are staggered relative to each other to form tongues. These tongues are receivable within individual longitudinal grooves formed in the underside of the upper flange and the upper side of the lower flange.
In ano~her type of wooden I-beam, the web portion is formed from multiple layers of thin wooden slats with the slats of adjacent layers bonded in ': , !
face-to-face contact with each other. The flange portions of the beam are built up by placing elongate, rather narrow strips of wood on opposite sides of the web member so that the strips are disposed parallel to the plane of the web. Although this particular type of construction enables the beam to be assembled from narrow leng~hs of wood, assembling the web with these componen~s involves a slow, time-consuming ~operation. Examples of this general type of wooden I-beam construction wherein the slats of one web layer , ;
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are positioned diagonally to the slats of an adjacen~
web layer are disclosed by Burke et al, U.S. Patent 2,382,201, and Brosenius, U.S. Patent 2,886,857.
In U.S. Patent 2,118,048 to Landsem, the web portion of the beam is composed of horizontally disposed plywood slats with the slats of one layer v~ertically offset from the slats of an adjacent layer.
Another type of known wooden I-beam construction includes upper and lower flanges which are vertically spaced apart by struts which extend across the full width of the flanges. The struts are spaced along the length of the beam with individual web panels disposed between adjacent stru-ts to underlie the upper flange and overlie the lower flange. An example of an I-beam utilizlng this particular construction is disclosed by Troutner, U.S~ Patent 3,490,188, wherein the upper and lower flanges are composed of a single length of board, the struts are cons~ructed from short upright wooden members and the web panels are each formed from plywood material. In U.S. Patent
are positioned diagonally to the slats of an adjacen~
web layer are disclosed by Burke et al, U.S. Patent 2,382,201, and Brosenius, U.S. Patent 2,886,857.
In U.S. Patent 2,118,048 to Landsem, the web portion of the beam is composed of horizontally disposed plywood slats with the slats of one layer v~ertically offset from the slats of an adjacent layer.
Another type of known wooden I-beam construction includes upper and lower flanges which are vertically spaced apart by struts which extend across the full width of the flanges. The struts are spaced along the length of the beam with individual web panels disposed between adjacent stru-ts to underlie the upper flange and overlie the lower flange. An example of an I-beam utilizlng this particular construction is disclosed by Troutner, U.S~ Patent 3,490,188, wherein the upper and lower flanges are composed of a single length of board, the struts are cons~ructed from short upright wooden members and the web panels are each formed from plywood material. In U.S. Patent
3,849,963 to Harmon, the upper and lower flanges are each composed of a plurality of flatboards stacked on top of each other, the strut members are composed of a s~ack of individual, short, horizontally disposed wooden members, and the web panels are each formed from a pair of thin wooden sheets spaced apart by a central layer of polystyrene foam.
Structural members have also been constructed from a combination of wooden and metal components.
An example of one such type of member includes hollow metal flanges each formed in a generally rectangularly , 1: ' i ,. , I
, ~ -3 -... ........ ..
. . ,, ! . : ~ . . , , , " ' ' ,.'' ''' " ' ~ '. , , ' , . ' ' ', ';, ~ ,2 shaped cross section which define a U-shaped yroove extending centrally along the length of the flange for receiving the upper and lower edge portions of a plywood web to thereby form a structural I-beam.
The side walls of the groove are serrated to penetrate into, and interlock with, the adjacent faces of the plywood web. An example of an I-beam of t:his type of construction is disclosed by Meyer, U.S. Patent .. . . .
Structural members have also been constructed from a combination of wooden and metal components.
An example of one such type of member includes hollow metal flanges each formed in a generally rectangularly , 1: ' i ,. , I
, ~ -3 -... ........ ..
. . ,, ! . : ~ . . , , , " ' ' ,.'' ''' " ' ~ '. , , ' , . ' ' ', ';, ~ ,2 shaped cross section which define a U-shaped yroove extending centrally along the length of the flange for receiving the upper and lower edge portions of a plywood web to thereby form a structural I-beam.
The side walls of the groove are serrated to penetrate into, and interlock with, the adjacent faces of the plywood web. An example of an I-beam of t:his type of construction is disclosed by Meyer, U.S. Patent .. . . .
4,019,302. ' Anothe~ known type of metallic structural member includes a pair of identically shaped halves which can be clamped together to either interconnect two longitudinally abutting, similarly shaped metal beams or alternatively the two halves can be clamped to the end portion of a single metal beam to extend its effective length. Each such half is generally channel shaped~in cross section, having a pair of parallel, vertically spaced apart flanges joined together by a vertical web portion. In use, the web portions of the two halves are disposed facing each other and bolted together to clamp the web portion of the two interconnected beams therebetween. An example of a beam of this general construction is disclosed by U.S. Patent 4,070,84~ to Cody.
1 , Disclosure of the Invention The present invention rela~ s to a novel structural I~b,eam which, in basic form, is charac-terized by twoi oppositely shaped halves joined together ln side-by-side relationship. Each half is composed of a flat, elongate central panel which is bonded .. .
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to the central panel of the opposite hal~ to form the web portion of the beam. Each beam half also includes an integral, formed, upper flange portion which extends upwardly and transversely outward:Ly from its corres-ponding central panel to partially surround a horizontally disposed, longitudinal upper chord member. Each beam half is further composed of an int;egral, formed, lower flange portion which extends transversely outwardly and downwardly from its corresponding central panel to partially surround a horizontally disposed, longi~
tudinal lower chord member.
The two oppositely shaped halves are each composed of thin wooden laminations bonded together and formed to assume ~he shape of the upper flange portion, the central web panel and the lower flange portion of each beam half. The two beam halves and the upper and lower chords are all bonded or otherwise secured together to form the ~-beam.
Preferably the upper and lower chord members are of substantially the same width and are considPrably wider than thelthickness of the beam web portion.
~ach of the chords can be formed from a solid length of wooden material, or alternatively from a plurality of very thin wooden laminations bonded together into a unitary member and then secured to its corresponding flange portions.
In one typical form of the present invention, the upper flange portion of each beam half includes a diagonal upper panel which extends upwardly and transversely outwardly from a corresponding central .
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panel to interconnect with the lower edge of a vertical, upwardly extending panel. The lower flange portion also includes a diagonal lower panel which extends downwardly and transversely outwardly to interconnect with the upper edge of a vertical, downwardly extending flange panel. The upper diagonal panels and the upper vertical flange panels of the two flange halves, which are disposed in parallel, spaced apart relationship to each other, cooperate to define an upwardly open trough for snugly receiving the upper chord member between them. Likewise, the lower diagonal panels and the vertical flange panels of the flange halves cooperate with each other to define a downwardly open lower trough for receiving therebetween the snugly fitting lower chor~ member.
In another typical form of the present invention, the upper and lower flange portions of each beam half are generally channel shaped. The upper fl~nge portion includes a firs~ horizontal panel extending transverseIy outwardly from the upper edge portion of the central panel, a vertical panel extending upwardly from the 1, ! . , outer edge of the first horizontal panel, and a second horizontal panel extendlng transversely inwardly from the upper edge of~the vertical panel. Likewise, ~he lower flange portion includes a first horizontal panel ~extending transversely outwardly from the lower edge portion of the central panel, a vertical panel extending downwardly from the outer edge portion of the first horizontal panel, and a second horizontal panel extending transversely inwardly from the lower edge portion of the vertical panel. The upper flange portions of the two beam halves cooperate together to closely ' ' ' i ~ ; ~, i ', ~ 6-. ' . .
surround an upper, rec-tangularly shaped chord member, while the lower flange portions of the two beam halves cooperate together to closely surround a lower, rectangu-larly shaped chord member. I
.- According to another aspect of one form of the present invention, a flat reinforcing plate is ~sandwiched between the ~o central panels to increase the thickness of the web portion of the beam. The , ,reinforcing plate extends vertically upwardly to abut against the underside of the upper chord member and vertically downwardly to abut against the upper side of the lower chord member. The reinforcing plate can be formed from a solid length of wooden material, ~or!alternatively from a plurality of very thin wooden sheets laminated together into a unitary member.
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,; According to a further aspect of the present invention, a centrally located, narrow slot extends vertically through each end portion of the beam for receiving a mounting bracket which serves to attach the end of the beam to a vertical column. Each end ;
portion of the beam furtherlincludes a cross hole which extends transversely through the beam web portion for receiving a fastener which also extends through an openin~ provided in the mounting bracket to thereby fixedly secure the bracket to the beam. Also, each end portion of the beam includes an additional pair of transverse through holes, one located above the central hole to extend through the beam upper flange portion and another located below the central hole to extend through the beam lower flange portion. These two cross holes receive fasteners to also s~cure the mounting , 1, .
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bracket to ~he beam and further prevent any rel~tive movement between the chord members and their corres-,, ~ ponding flange portions.
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It is a primary object of the present inven-tion to provide a structural beam constructed from components ofjmolded, laminated material bonded together to form a uni~ary structure which is capable of supporting a much larger load than,can be safely carried by a singular, non-laminated member of the same type o~
wooden material, and having a cross section of equal ,.
size and shape.l ', . . .
A further object of the present invention is to provide a composite structural beam which can utilize almost all of the wood of a log in the construc-tion of the beam.
I Another object of the present invention is to'provide a wooden structural beam havlng a decorative, esthetically pleasing appearance to thereby enable the beam to remain exposed to either the exterior orlinterior of a dwelling, office or other type of building ! li One more object of the present invention is to provide a wooden structural beam which can be economi-cally and easily fabricated from very thin lay~rs of wooden material which are simultaneously laminated , together and molded into a desired cross-sectional , configuration.
Yet another object of the present invention is to provide a wooden structural beam design which can be easily altered to increase or decrease the - ~
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section modulus of the beam to thereby vary the load which can be safely carried by the beam.
The present invention is directed to a wooden structural beam. The wooden structural beam comprises an elongate upper chord member, an elongate lower chord member, and two oppositely shaped halves disposed in side-by-side relationship to each other. Each half includes an elongate, flat central panel bonded to the central panel of the opposite half to form the web portion of the beam, an integral formed upper edge portion extending upwardly and transversely outwardly from a corresponding central panel, the upper edge portions of the beam halves cooperating together to define an upwardly open trough between them for snugly receiving the upper chord member for forming the upper flange portion of the beam, and an integral, formed lower edge portion extending downwardly and transversely outwardly from each central panel, the lower edge portions of the beam halves cooperating together to define a downwardly open trough therebetween for -;~ snugly receiving the lower chord member for forming the lower flange portion of the beam. Each end of the beam includes portions defining a slot extending vertically through, and longitudinalIy inwardly from, each of the beams.
The end portion of the beam may include portions defining cross holes extending transversely through the beam web portion through the beam upper edge portion and the upper chord member, and the beam lower edge portion and its lower chord. ~he structural beam may further comprise a flat, relnforcing plate sandwiched between the central panel of the two beam halves.
One aspect of the invention is a wooden struc-tural I-beam, comprising:
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two oppositely shaped halves bonded together in side-by-slde relationship, each of the halves composed of a plurality of very thin wooden laminations bonded together and molded to define:
a flat, vertical, horizpntally elonga-te web panel;
first upper and lower transverse flange panels extending horizontally and transversely outwardly from the upper and lower edge portions, respectively, of the web panel, upper and lower vertical flange panels extend-ing upwardly and downwardly, respectively, from an outer edge portion of a horizontal flange panel, and the web panels of the two beam halves bonded together in face-to-face relationship whereln the upper transverse flange panels and upper verticaI panels co-operating together to form an upwardly open trough along the length of the beam, and the lower transverse panels and the lower vertical panels cooperating together to :~20 form a downwardly open trough extending the length of the beam;
an upper, horizontally elongate chord member snugly receivable within the upper trough; and . ~ a lower, horizontally elongate chord member snugly receivable within the lower trough;
the wooden structural I-beam further comprising a slot extendlng vertically through, and inwardly from each end of, the beam, and additionally comprising a hole extending transversely through the web panels of the two beam halves, a hole extending transversely through the upper and lower flange panels of the two beam halves and their corresponding upper and lower chord members, respectively.
-8b-Each beam half may include a second upper trans-verse flange panel extending horizontally and transversely inwardly from the upper edge portion of a corresponding upper vertical flange panel, the second upper transverse flange panels of the two beam halves substantlally completely over-lying the upper surface of the upper chord member; and a second lower transverse flange panel extending -transversely and horizontally inwardly from the lower edge portion of a : corresponding lower vertical flange panel, the second lower transverse flange panel of the two beam halves substantially completely underlying the lower surface of the lower chord member.
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Brie~ Description of the Drawi~s.
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FIG. 1 is a fragmentary, isometric view illus-trating a building utiliziny structural beams typically constructed according to the present invention;
FIG. 2 is an enlarged, isometric, exploded, fragmentary view illustrating the interrelationship between structural beams typifying the present invention with other structural components used in the formation of a building frame structure;
: FIG. 3 is a greatly enlarged, cross-sectional view of the typical embodiment of the present invention shown in FIG. 2 and ta~en substantially along lines 3-3 thereof;
FIG. ~ is à greatly enlarged, cross-sectional ~iew similar to FIG. 3 of an alterna~ive typlcal embodi-ment of the present invention utilizing a reinforcing plate;
FIG. 5 is a greatly enlarged, cross-sectional view of anoth~.r typical embodiment ofithe pr~sen~
invention illustrating an alternative flange portion configuration; and FIG. 6 is a greatly enlarged, cross-sectional : view similar tc7 FI~. S of a further typical embodiment ofthe present inventlon utilizing a reinforcing plate.
Best Mode for Carryinq Out the Invention ~ ' .
Referring initially to FIG. 1~ a plurality of ~tructural beams lO constructed according to the g _ , ~ r~ ~
uest mode of the present invention currently known to applicant are utilized to form part of a framework 12 for building 14. Additionally, referring to FIGS.
2 and 3, the beam 10 is composed of two oppositely , . .
shaped halves 16 adhesively bonded or otherwise secured together in side-by-side relationship along the vertical axis of symmetry VS of the beam. Each beam half 16 includes a flat central panel 18 which is bonded in face-to-face relationship wi,th the central panel of the'opposite beam half to cooperatively form the web portion of beam 10. Each beam half 16 also includes an upper, angularly shaped flange portion 19 integrally formed with a corresponding central panel. The upper flange portion 19 includes an upper diagonal panel 20 extending upwardly and transversely outwardly from the upper edge portion of a central panel 18 in the opposite direction from the vertical line of symmetry VS. Upper flange portion 19 also includes vertical panel 22 which exten~s upwardly from the upper edge portion of upper diagonal panel 20 in a plane parallel to the plane of central panel 18. The vertical panels 22 of the two beam halves 16! extend upwardly the same distance, which distance is substantially less than the ver~ical height of central panel 18. The two upper vertical panels 22 are, furthermore, offset oppositely away from each other to define a horizontally elongate, upwardly open trough between them for snugly receiving a rectangularly shaped7 upper chord member 24 which is bonded to the inside surfaces of panels 22, as by a suitable adhesive. The upper surface of cho~d member 24 is preferably flush with the upper , . . . . , .
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edges of vertical panels 22, but also can extend above, or be recessed below, the upper edges of vertical panels Z2. Further, chord Z4 extends downwardly to the intersection of vertical and diagonal panels 22 and 20, respectively.
Preferably, each upper diagonal panel 20 is disposed at an angle X from the plane of central panel 18, which is ideally approximately 60 degrees.
However, diagonal panels 20 can be disposed at other angular orientations relative to central panel 18, and even can be located perpendicularly to central panel 18 to assume a horizontal orientation to underlie the lower surface of chord member ~4.
Each beam half 16 also includes an angularly shaped lower flange portion;25 which is integrall~
formed with a corresponding central panel 18. Lower flange portion 25 includes a lower diagonal panel 26 which extends downwardly and transversely outwardly from the lower edge portion of central panel 18 in a direction oppositely from the vertical line of symmetry 'VS. As with upper diagonal panel 20, lower dia~onal panel 26 is located at an angle X from the plane o~ central panel 18, which angle is preferably 60 degrees. However, lower diagonal panel Z6 can be posi-tioned at other angular orientations relative to central panel 18, including being disposed in a horizontal plane. Each lower flange portlon 25 further includes .a vertical panel 28 which extends downwardly from a lower edge portion of its corresponding diagonal panel 26 to lie in a plane parallel to the plane of central panel 2~. The two lower panels 28 are disposed : ! ~ ' i . i . , ~ - , , : ! ;
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transversely ou~wardly from their corresponding central panels 18 to define a downwardly open trough extendin~
the length of beam 10 for snugly receiving a lower chord 30 which is bonded to the inside surfaces of vertical panels 28. Chord 30 is preferably disposed flush with the lower edges of vertical panels 2~ and extends upwardly to an elevation corresponding ~o the intersection of the vertical panels with their corresponding diagonal panels 28. However, chord 30 ; . can be recessed above, or extended below, the lower I edges of ver~ical panels 28 and not depart from the scope of the present invention.
Each beam half 16 is composed of elongate, very thin sheets of wooden material laminated togetller with a suitable adhesive, such as phenolaldehyde with ~ viscosity of approximately lS00 centipoise and at an application rate of 100 grams per square meter.
To form each beam half 16, a plurality of wooden sheets are placed on top of each after the adhesive has been applied to one surface of each of the layers. The stack of wooden sheets are then placed within a mold under pressure of approximately 10 kilograms per square centimeter and an elev~ted temperature of approximately 140C. to simultaneously cure the adhesive and form upper and lower diagonal panels 20 and 26, respect-ively, and upper and lower vertical panels 22 and 28, respectively. After the molding and curing process is completed, the newly formed beam half is removed from the mold ancl then its ends and the upper and lower edges are trimmed into the cross-sectional profile illustrated in FIG.3. To maximize the strength of .
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oeam 10, some of the shee-ts of wooden ]aminate composing each beam half 16 can be angularly oriented relative to each other so tha-t the direction of their grains are perpendicular to each other, or at least not aligned with each other. This construction enables the beam to carry significant loads in more than only one direction.
Once beam halves 16 have been forrned, beam lO is assembled by first coating the inwardly directed surfaces of each beam half withladhesive and then placing central panels 18 in face-to-face relationship with each other, After the side surfaces of chord members 24 and 30 also have b~en coated with the adhesive, upper chord member 24 is inserted between upper vertical panels 22 and lower chord member 30 irserted between lower ver~ical panels 2a ~ as illustrated in FIG. 3.
So assembled, the components of beam lO are placed within a mold under a pressure of approximately 10 kilograms per square centimeter and at an elevated temperature of approximately 140C. to cure the bonding adllesive.
Chords 24 and 30 are illustrated in FIGS.
2 and 3 as being rectangular in'cross section, extending the full length of beam lO, and composed of a solid piec~ of wooden material. The cords 24 and 30, alter-natively, can be constructed from very thin wooden strips laminated together to form a unitary structure in a manner similar to the cons,truction of beam halves 16.
It will be appreciated that, by constructing beam lO in the manner described above with integrally .
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.' ' ' , ' ~ormed halves 16 bonded together, a structure resul~s which is capable of carrying a significantly larger vertical load than one constructed from individual planar components assellbled together to form a beam of the same cross-sectional shape and size. Also, the integral construction of the beam halves and the secure bond between the beam halves and chord members enables beam 10 to withstand large horizontal impact loads, such as during an earthquake.
Furthermore, the very thin sheets composing beam halves 16 can be formed by continuously peeling a log rather than by cutting the log into a few large cross-sectional shapes. As a consequence, almost all of the wood from a log can be u-tilized to form beam 10 so that very little waste, if any, occurs. This is very important since trees, ! like almost all other natural resources, are being used at an ever increasing rate and thus becoming more and more scarce.
Next referring specifically to FIG. 2, each end portion of beam 10 includes a narrow slot 32 extend-ing vertlcally through the full depth of the beam and a short distance longltudinally inwardly from the end of the beam. Preferably, slot 32 is aligned with the vertical line of symmétry VS of beam 10.
The end portion of each beam 10 also includes a circular hole 34 extending transversely through the flange portion thereof at an elevation preferably approximately halfway between the top and bottom edges of the beam.
Each beam end portion further includes an addi~ional pair of holes 35, one extending transversely through upper vertical panels 22 and their corresponding chord , . I ' . .
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member 24 and the other extending ~ransversely through lower vertical panels 28 and ~heir corresponding chord member 30.
As a specific, but, nonlimiting, example of . the ~ypical embodiment of the present invention, the very thin wooden laminations used to fabricate beam halves 16 can be each approximately 10 mi]limeters, (hereafter "mm") thick to fornl beam halves 16 in a ~hickness of approximately 10 mm. Laminations of typically 1.0 mm thickness can also be used to construct chord members 24 and 30 in a width of approximately 50 mm l ` and a depth of approximately 40 mm to result in flange . portions 19 and 25 having an overall width of approxi-mately 70 m-n. Applicant has found that by fabricating beam 10 with these dlmensions and also by forming the beam with a total depth of approxima~ely 250 mm, the beam is of a sufficient strength to be widely used in the frame s.tructure of a house, office or similar building. However, beam 10 can be formed . in sizes other than with these particular di.mensions to thereby vary its load carrying capacity. Furthermore, beam halves lG and. chord members 24 and 30 can be composed of laminations of thicknesses other than approximately 1.0 mm and still allow essentially all ~` of the wood from a log to be utilized to fabricate beam 10.
FIGS. 1 and 2 illustrate one typical Inanner in which beam 10 can be used to form part of a typical framework 12 of a building structure 14. As most clearly illustrated in FIG. 2, the vertical wall 36 of a T-shaped brachet 38 is slidably receivable with . . , ; . -15- .
the beam slot 32 with heel portion 40 of the bracke~
underlying tlle bottom edge of beam 10 at 41. The beam can be recessed or slo~ed at 41 so tha~ ~he bo~tom surface of heel portion 40 is flush wi-th the bottom edge of the beam. Alternatively, beam 10 can be formed without such a recess and heel portion 40 can simply un~erlie the lower edge of the beam. Additionally the heel portion 40 can be made somewhat narrower than the width of the lower flange o~ the beam so that it is not readily visible. Bracket 38 is attached to the end por~ion Qf bearn 10 by a central capscrew 42 which extends through beam hole 34 and a corresponding hole 44 formed in bracket vertical wall 36 to engage with a nut 45 and by a pair of longer capscrews 46 which extend through beam hoies 35 and corresponding I holes 47 to engage with nuts 49. T-bracket 38 also includes a plurality of hooks 48 which engage within vertically aligned, correspondingly spaced apart slots 50 formed in each of the four sides of a hollow block 52. Block 52 is in turn coupled between the adjacent end portions of vertical columns 54 by coupler members i 56 each of which can be composed of an open square shaped plug portion 58 which slidably engages within a correspondingly shaped socket, not shown, formed in each end portion of column 54, and a circular stud 60 which slidably engages within a central hole 52 provided in each end of block SZ. Thus, once T-bracket 38 has been bolted or otherwise fastened to the end portion of beam 10, the beam can be quickly, and con-veniently assembled with column(s) 54 by simply engaging hooks 48 in~o block slots 50.
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..s illustra~ed in FIG. 1, beams 10 can be overlayed by a floor panel 63 which leaves the beams exposed from below. Because of their pleasing and decorative appearance, beams 10 do no~ have to be covered by, or encased wit;hin plaster, gypswn board, paneling or other interior building materials, thus resulting in an economical, attractive construction.
It will be appreciated that beams 10 can be attached to columns 52 in other ways. Furthermore, beam 10 can function as a floor or a ceiling jois-t wherein i-ts ends are attached to a transversely extending headers or beams.
FIG. 4 illustrates an alternative ~ypical embodiment of the present invention wherein a fla~
reinforcing plate 64 is sandwiched between, and bonded to, central panels lla to increase the width of the beam web portion, and thus the section modulus of beam 110, to thereby enable the beam to carry an increased load over the load which can be safely carried by beam 10. Preferably plate 6~ stretches the full length of beam 110, and extends vertically from the lower surface of upper chord 124 to the upper surface of lower chord 130, to thus additionally support the two chords~ To compensate for the greater width separa-ting upper vertical panels 122 from each other and lower vertical panels 12B from each other due to the addition of the reinforcement plate 6/, the width of upper and lower chords 124 and 130, respec~ively, are increased by ~he thickness of plate 64. O~her than the addition of plate 64, the manner of constructing and assemblin~ beam 110 is essentially the same as tha~ of beam 10.
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: ~lthough plate 64 can be formed from a single ; thickness of woo~en material, prefe~ably it is constructed from a plurality of very thin wooden sheets, ideally approximately 1.0 mm thick, bonded together with a suitable adhesive, such as phenolaldehydel resin, in a manner similar to the fabrication of beam halves 16. The thickness of plate 64 can be selectively varied to alter the level of load which can be safely carried by beam 110. As the thickness of plate 64 is varied, the only adjustments which must be made to beam 110 is altering the width separating flange panels 122, and 128 and the thickness of chords 124 and 130.
A further typical embodimen~ oE the presen~
invention is illustrated in FIG. 5, wherein beam 210 I is constructed and dimensioned similarly to beam 10 illustrated in FIG. 3, with the exception that upper panels 220 are disposed horizontally to underlie upper chord member 224 rather than being disposed di.agonally in the manner of upper panels 20. Lil:ewise, lower : panels 226 are disposed horizontally to overlie the upper surface of lower chord member 230 rather than at a diagonal orientation in the manner of lower panel !
26, FIG. 3. In another difference between beams 10 and 210, the upper flange portion 219 of each beam . half 216 includes a top horizontal panel 266 which extends transversely inwardly from a correspondin~
upper edge of vertical panel 222 to abut against the top horizontal panel 266 of opposite beam halE 21G
at the vertical l:ine of symmetry VS of beam 10. Likewise, each beam half lower flan~e portion 225 includes a '' ' ~ 18~
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. bottom horizontal panel 26~ which extends transversely inwardly - from the lower edge portion of vertical panel 230 to abut against the bottom horizontal panel 268 of the opposite beam half 216 at the vertical line of symmetry VS of beam 10.
By constructing beam halves 216 in the manner described above, the flange upper portions 219 define a rectangularly shaped cavity for receiving a closely fitting, rectangularly shaped chord member 224. Likewise, the lower flange portion 225 of beam halves 216 form a cavity having a rectangular cross section for snugly receiving a rectangularly shaped, lower chord member : 230. By encasing upper chord 226 and lower chord 230 in this manner, only the outer surface of beam halves 216 are visible. This particular construction enables beam halves 216 to be formed with an outer cosmetic layer of mahogany, oak or similar wGod to ~ive beam 210 a highly decorative appearance. As a consequence, beam 210 can be left exposed rather than being covered with additional building materials.;
One further typical embodiment of Lhe present invention is illustrated in FIG. 6, whérein beam 310 is construc~ed similarly to beam 210 illustrated in FIG. 5, with the exception that a flat reinforcing plate 370 is sandwiched between central panels 318 to thereby enlarge the load carrying capacity of the beam by increasing its section modulus. Ideally, reinforcing plate 370 extends the full length of beam 310 and also extends vertically from the lower surface of upper chord member 324 to the upper surface of lower chord.330 to thereby reinforce the two chords.
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To accommodate the addition of reinforcing pla~e 370, the width of horizontal panels 372 and 320 of upper flange portion 319 are widened by half the thickness of pla~e 370. Likewise, the width of horizontal panels 326 and 374 of lower flange portion 3Z5 are enlarged by half the thickness of plate 370. Also, the width of upper chord member 324 and lo~ler chord member 330 are increased by the thickness of plate 370.
- As with reinforcing plate 64, illustrated in FIG. 4, plate 370 can also be forrned from a single thickness of wooden material; however, ideally, plate 370 is constructed from a plurali~y of very ~hin wooden . sheets each ideally about 1.0 mm thick bonded together with a sui~able adhesive, such as phenolaldehyde resin.
The thickness of plate 370 can be selective.ly altered in response to the load to be carried by the plate, 7 ~ ' with the only required change to the components of ~ beam 310 is the altering of the widt.h of flan~e panels 372, 374, 320 and 326 and the thickness of chords 324 and 330. Also the thickness of the laminations used to fabricate plate 370 can be changed to acco~nmodate the particular type of wood used tolconstruct the plate.
With the exception that plate 370 must be formed and then placed between central plates 318, the manner of constructing beam 310 is essen~ially identical to that of beam 210. Also beam 310 is assembled . with columns 54 in the same manner as is beam 10 as described above.
The invention may be embodied in other specific for ~ ~r embo~ nenes ~itho~t de~r~ from the ~pirit ~. . .~ I i or essential characteristics thereof. The typical embodiments of structural beams, described above, are therefor to be considered in all respects as illustrative and not restrictive. The scope of the invention is set forth in the appended claims rather than being limited to the specific typical en!bodiments of structural beams described in the foregoing description.
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1 , Disclosure of the Invention The present invention rela~ s to a novel structural I~b,eam which, in basic form, is charac-terized by twoi oppositely shaped halves joined together ln side-by-side relationship. Each half is composed of a flat, elongate central panel which is bonded .. .
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to the central panel of the opposite hal~ to form the web portion of the beam. Each beam half also includes an integral, formed, upper flange portion which extends upwardly and transversely outward:Ly from its corres-ponding central panel to partially surround a horizontally disposed, longitudinal upper chord member. Each beam half is further composed of an int;egral, formed, lower flange portion which extends transversely outwardly and downwardly from its corresponding central panel to partially surround a horizontally disposed, longi~
tudinal lower chord member.
The two oppositely shaped halves are each composed of thin wooden laminations bonded together and formed to assume ~he shape of the upper flange portion, the central web panel and the lower flange portion of each beam half. The two beam halves and the upper and lower chords are all bonded or otherwise secured together to form the ~-beam.
Preferably the upper and lower chord members are of substantially the same width and are considPrably wider than thelthickness of the beam web portion.
~ach of the chords can be formed from a solid length of wooden material, or alternatively from a plurality of very thin wooden laminations bonded together into a unitary member and then secured to its corresponding flange portions.
In one typical form of the present invention, the upper flange portion of each beam half includes a diagonal upper panel which extends upwardly and transversely outwardly from a corresponding central .
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panel to interconnect with the lower edge of a vertical, upwardly extending panel. The lower flange portion also includes a diagonal lower panel which extends downwardly and transversely outwardly to interconnect with the upper edge of a vertical, downwardly extending flange panel. The upper diagonal panels and the upper vertical flange panels of the two flange halves, which are disposed in parallel, spaced apart relationship to each other, cooperate to define an upwardly open trough for snugly receiving the upper chord member between them. Likewise, the lower diagonal panels and the vertical flange panels of the flange halves cooperate with each other to define a downwardly open lower trough for receiving therebetween the snugly fitting lower chor~ member.
In another typical form of the present invention, the upper and lower flange portions of each beam half are generally channel shaped. The upper fl~nge portion includes a firs~ horizontal panel extending transverseIy outwardly from the upper edge portion of the central panel, a vertical panel extending upwardly from the 1, ! . , outer edge of the first horizontal panel, and a second horizontal panel extendlng transversely inwardly from the upper edge of~the vertical panel. Likewise, ~he lower flange portion includes a first horizontal panel ~extending transversely outwardly from the lower edge portion of the central panel, a vertical panel extending downwardly from the outer edge portion of the first horizontal panel, and a second horizontal panel extending transversely inwardly from the lower edge portion of the vertical panel. The upper flange portions of the two beam halves cooperate together to closely ' ' ' i ~ ; ~, i ', ~ 6-. ' . .
surround an upper, rec-tangularly shaped chord member, while the lower flange portions of the two beam halves cooperate together to closely surround a lower, rectangu-larly shaped chord member. I
.- According to another aspect of one form of the present invention, a flat reinforcing plate is ~sandwiched between the ~o central panels to increase the thickness of the web portion of the beam. The , ,reinforcing plate extends vertically upwardly to abut against the underside of the upper chord member and vertically downwardly to abut against the upper side of the lower chord member. The reinforcing plate can be formed from a solid length of wooden material, ~or!alternatively from a plurality of very thin wooden sheets laminated together into a unitary member.
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,; According to a further aspect of the present invention, a centrally located, narrow slot extends vertically through each end portion of the beam for receiving a mounting bracket which serves to attach the end of the beam to a vertical column. Each end ;
portion of the beam furtherlincludes a cross hole which extends transversely through the beam web portion for receiving a fastener which also extends through an openin~ provided in the mounting bracket to thereby fixedly secure the bracket to the beam. Also, each end portion of the beam includes an additional pair of transverse through holes, one located above the central hole to extend through the beam upper flange portion and another located below the central hole to extend through the beam lower flange portion. These two cross holes receive fasteners to also s~cure the mounting , 1, .
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bracket to ~he beam and further prevent any rel~tive movement between the chord members and their corres-,, ~ ponding flange portions.
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It is a primary object of the present inven-tion to provide a structural beam constructed from components ofjmolded, laminated material bonded together to form a uni~ary structure which is capable of supporting a much larger load than,can be safely carried by a singular, non-laminated member of the same type o~
wooden material, and having a cross section of equal ,.
size and shape.l ', . . .
A further object of the present invention is to provide a composite structural beam which can utilize almost all of the wood of a log in the construc-tion of the beam.
I Another object of the present invention is to'provide a wooden structural beam havlng a decorative, esthetically pleasing appearance to thereby enable the beam to remain exposed to either the exterior orlinterior of a dwelling, office or other type of building ! li One more object of the present invention is to provide a wooden structural beam which can be economi-cally and easily fabricated from very thin lay~rs of wooden material which are simultaneously laminated , together and molded into a desired cross-sectional , configuration.
Yet another object of the present invention is to provide a wooden structural beam design which can be easily altered to increase or decrease the - ~
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section modulus of the beam to thereby vary the load which can be safely carried by the beam.
The present invention is directed to a wooden structural beam. The wooden structural beam comprises an elongate upper chord member, an elongate lower chord member, and two oppositely shaped halves disposed in side-by-side relationship to each other. Each half includes an elongate, flat central panel bonded to the central panel of the opposite half to form the web portion of the beam, an integral formed upper edge portion extending upwardly and transversely outwardly from a corresponding central panel, the upper edge portions of the beam halves cooperating together to define an upwardly open trough between them for snugly receiving the upper chord member for forming the upper flange portion of the beam, and an integral, formed lower edge portion extending downwardly and transversely outwardly from each central panel, the lower edge portions of the beam halves cooperating together to define a downwardly open trough therebetween for -;~ snugly receiving the lower chord member for forming the lower flange portion of the beam. Each end of the beam includes portions defining a slot extending vertically through, and longitudinalIy inwardly from, each of the beams.
The end portion of the beam may include portions defining cross holes extending transversely through the beam web portion through the beam upper edge portion and the upper chord member, and the beam lower edge portion and its lower chord. ~he structural beam may further comprise a flat, relnforcing plate sandwiched between the central panel of the two beam halves.
One aspect of the invention is a wooden struc-tural I-beam, comprising:
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two oppositely shaped halves bonded together in side-by-slde relationship, each of the halves composed of a plurality of very thin wooden laminations bonded together and molded to define:
a flat, vertical, horizpntally elonga-te web panel;
first upper and lower transverse flange panels extending horizontally and transversely outwardly from the upper and lower edge portions, respectively, of the web panel, upper and lower vertical flange panels extend-ing upwardly and downwardly, respectively, from an outer edge portion of a horizontal flange panel, and the web panels of the two beam halves bonded together in face-to-face relationship whereln the upper transverse flange panels and upper verticaI panels co-operating together to form an upwardly open trough along the length of the beam, and the lower transverse panels and the lower vertical panels cooperating together to :~20 form a downwardly open trough extending the length of the beam;
an upper, horizontally elongate chord member snugly receivable within the upper trough; and . ~ a lower, horizontally elongate chord member snugly receivable within the lower trough;
the wooden structural I-beam further comprising a slot extendlng vertically through, and inwardly from each end of, the beam, and additionally comprising a hole extending transversely through the web panels of the two beam halves, a hole extending transversely through the upper and lower flange panels of the two beam halves and their corresponding upper and lower chord members, respectively.
-8b-Each beam half may include a second upper trans-verse flange panel extending horizontally and transversely inwardly from the upper edge portion of a corresponding upper vertical flange panel, the second upper transverse flange panels of the two beam halves substantlally completely over-lying the upper surface of the upper chord member; and a second lower transverse flange panel extending -transversely and horizontally inwardly from the lower edge portion of a : corresponding lower vertical flange panel, the second lower transverse flange panel of the two beam halves substantially completely underlying the lower surface of the lower chord member.
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Brie~ Description of the Drawi~s.
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FIG. 1 is a fragmentary, isometric view illus-trating a building utiliziny structural beams typically constructed according to the present invention;
FIG. 2 is an enlarged, isometric, exploded, fragmentary view illustrating the interrelationship between structural beams typifying the present invention with other structural components used in the formation of a building frame structure;
: FIG. 3 is a greatly enlarged, cross-sectional view of the typical embodiment of the present invention shown in FIG. 2 and ta~en substantially along lines 3-3 thereof;
FIG. ~ is à greatly enlarged, cross-sectional ~iew similar to FIG. 3 of an alterna~ive typlcal embodi-ment of the present invention utilizing a reinforcing plate;
FIG. 5 is a greatly enlarged, cross-sectional view of anoth~.r typical embodiment ofithe pr~sen~
invention illustrating an alternative flange portion configuration; and FIG. 6 is a greatly enlarged, cross-sectional : view similar tc7 FI~. S of a further typical embodiment ofthe present inventlon utilizing a reinforcing plate.
Best Mode for Carryinq Out the Invention ~ ' .
Referring initially to FIG. 1~ a plurality of ~tructural beams lO constructed according to the g _ , ~ r~ ~
uest mode of the present invention currently known to applicant are utilized to form part of a framework 12 for building 14. Additionally, referring to FIGS.
2 and 3, the beam 10 is composed of two oppositely , . .
shaped halves 16 adhesively bonded or otherwise secured together in side-by-side relationship along the vertical axis of symmetry VS of the beam. Each beam half 16 includes a flat central panel 18 which is bonded in face-to-face relationship wi,th the central panel of the'opposite beam half to cooperatively form the web portion of beam 10. Each beam half 16 also includes an upper, angularly shaped flange portion 19 integrally formed with a corresponding central panel. The upper flange portion 19 includes an upper diagonal panel 20 extending upwardly and transversely outwardly from the upper edge portion of a central panel 18 in the opposite direction from the vertical line of symmetry VS. Upper flange portion 19 also includes vertical panel 22 which exten~s upwardly from the upper edge portion of upper diagonal panel 20 in a plane parallel to the plane of central panel 18. The vertical panels 22 of the two beam halves 16! extend upwardly the same distance, which distance is substantially less than the ver~ical height of central panel 18. The two upper vertical panels 22 are, furthermore, offset oppositely away from each other to define a horizontally elongate, upwardly open trough between them for snugly receiving a rectangularly shaped7 upper chord member 24 which is bonded to the inside surfaces of panels 22, as by a suitable adhesive. The upper surface of cho~d member 24 is preferably flush with the upper , . . . . , .
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edges of vertical panels 22, but also can extend above, or be recessed below, the upper edges of vertical panels Z2. Further, chord Z4 extends downwardly to the intersection of vertical and diagonal panels 22 and 20, respectively.
Preferably, each upper diagonal panel 20 is disposed at an angle X from the plane of central panel 18, which is ideally approximately 60 degrees.
However, diagonal panels 20 can be disposed at other angular orientations relative to central panel 18, and even can be located perpendicularly to central panel 18 to assume a horizontal orientation to underlie the lower surface of chord member ~4.
Each beam half 16 also includes an angularly shaped lower flange portion;25 which is integrall~
formed with a corresponding central panel 18. Lower flange portion 25 includes a lower diagonal panel 26 which extends downwardly and transversely outwardly from the lower edge portion of central panel 18 in a direction oppositely from the vertical line of symmetry 'VS. As with upper diagonal panel 20, lower dia~onal panel 26 is located at an angle X from the plane o~ central panel 18, which angle is preferably 60 degrees. However, lower diagonal panel Z6 can be posi-tioned at other angular orientations relative to central panel 18, including being disposed in a horizontal plane. Each lower flange portlon 25 further includes .a vertical panel 28 which extends downwardly from a lower edge portion of its corresponding diagonal panel 26 to lie in a plane parallel to the plane of central panel 2~. The two lower panels 28 are disposed : ! ~ ' i . i . , ~ - , , : ! ;
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transversely ou~wardly from their corresponding central panels 18 to define a downwardly open trough extendin~
the length of beam 10 for snugly receiving a lower chord 30 which is bonded to the inside surfaces of vertical panels 28. Chord 30 is preferably disposed flush with the lower edges of vertical panels 2~ and extends upwardly to an elevation corresponding ~o the intersection of the vertical panels with their corresponding diagonal panels 28. However, chord 30 ; . can be recessed above, or extended below, the lower I edges of ver~ical panels 28 and not depart from the scope of the present invention.
Each beam half 16 is composed of elongate, very thin sheets of wooden material laminated togetller with a suitable adhesive, such as phenolaldehyde with ~ viscosity of approximately lS00 centipoise and at an application rate of 100 grams per square meter.
To form each beam half 16, a plurality of wooden sheets are placed on top of each after the adhesive has been applied to one surface of each of the layers. The stack of wooden sheets are then placed within a mold under pressure of approximately 10 kilograms per square centimeter and an elev~ted temperature of approximately 140C. to simultaneously cure the adhesive and form upper and lower diagonal panels 20 and 26, respect-ively, and upper and lower vertical panels 22 and 28, respectively. After the molding and curing process is completed, the newly formed beam half is removed from the mold ancl then its ends and the upper and lower edges are trimmed into the cross-sectional profile illustrated in FIG.3. To maximize the strength of .
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oeam 10, some of the shee-ts of wooden ]aminate composing each beam half 16 can be angularly oriented relative to each other so tha-t the direction of their grains are perpendicular to each other, or at least not aligned with each other. This construction enables the beam to carry significant loads in more than only one direction.
Once beam halves 16 have been forrned, beam lO is assembled by first coating the inwardly directed surfaces of each beam half withladhesive and then placing central panels 18 in face-to-face relationship with each other, After the side surfaces of chord members 24 and 30 also have b~en coated with the adhesive, upper chord member 24 is inserted between upper vertical panels 22 and lower chord member 30 irserted between lower ver~ical panels 2a ~ as illustrated in FIG. 3.
So assembled, the components of beam lO are placed within a mold under a pressure of approximately 10 kilograms per square centimeter and at an elevated temperature of approximately 140C. to cure the bonding adllesive.
Chords 24 and 30 are illustrated in FIGS.
2 and 3 as being rectangular in'cross section, extending the full length of beam lO, and composed of a solid piec~ of wooden material. The cords 24 and 30, alter-natively, can be constructed from very thin wooden strips laminated together to form a unitary structure in a manner similar to the cons,truction of beam halves 16.
It will be appreciated that, by constructing beam lO in the manner described above with integrally .
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.' ' ' , ' ~ormed halves 16 bonded together, a structure resul~s which is capable of carrying a significantly larger vertical load than one constructed from individual planar components assellbled together to form a beam of the same cross-sectional shape and size. Also, the integral construction of the beam halves and the secure bond between the beam halves and chord members enables beam 10 to withstand large horizontal impact loads, such as during an earthquake.
Furthermore, the very thin sheets composing beam halves 16 can be formed by continuously peeling a log rather than by cutting the log into a few large cross-sectional shapes. As a consequence, almost all of the wood from a log can be u-tilized to form beam 10 so that very little waste, if any, occurs. This is very important since trees, ! like almost all other natural resources, are being used at an ever increasing rate and thus becoming more and more scarce.
Next referring specifically to FIG. 2, each end portion of beam 10 includes a narrow slot 32 extend-ing vertlcally through the full depth of the beam and a short distance longltudinally inwardly from the end of the beam. Preferably, slot 32 is aligned with the vertical line of symmétry VS of beam 10.
The end portion of each beam 10 also includes a circular hole 34 extending transversely through the flange portion thereof at an elevation preferably approximately halfway between the top and bottom edges of the beam.
Each beam end portion further includes an addi~ional pair of holes 35, one extending transversely through upper vertical panels 22 and their corresponding chord , . I ' . .
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member 24 and the other extending ~ransversely through lower vertical panels 28 and ~heir corresponding chord member 30.
As a specific, but, nonlimiting, example of . the ~ypical embodiment of the present invention, the very thin wooden laminations used to fabricate beam halves 16 can be each approximately 10 mi]limeters, (hereafter "mm") thick to fornl beam halves 16 in a ~hickness of approximately 10 mm. Laminations of typically 1.0 mm thickness can also be used to construct chord members 24 and 30 in a width of approximately 50 mm l ` and a depth of approximately 40 mm to result in flange . portions 19 and 25 having an overall width of approxi-mately 70 m-n. Applicant has found that by fabricating beam 10 with these dlmensions and also by forming the beam with a total depth of approxima~ely 250 mm, the beam is of a sufficient strength to be widely used in the frame s.tructure of a house, office or similar building. However, beam 10 can be formed . in sizes other than with these particular di.mensions to thereby vary its load carrying capacity. Furthermore, beam halves lG and. chord members 24 and 30 can be composed of laminations of thicknesses other than approximately 1.0 mm and still allow essentially all ~` of the wood from a log to be utilized to fabricate beam 10.
FIGS. 1 and 2 illustrate one typical Inanner in which beam 10 can be used to form part of a typical framework 12 of a building structure 14. As most clearly illustrated in FIG. 2, the vertical wall 36 of a T-shaped brachet 38 is slidably receivable with . . , ; . -15- .
the beam slot 32 with heel portion 40 of the bracke~
underlying tlle bottom edge of beam 10 at 41. The beam can be recessed or slo~ed at 41 so tha~ ~he bo~tom surface of heel portion 40 is flush wi-th the bottom edge of the beam. Alternatively, beam 10 can be formed without such a recess and heel portion 40 can simply un~erlie the lower edge of the beam. Additionally the heel portion 40 can be made somewhat narrower than the width of the lower flange o~ the beam so that it is not readily visible. Bracket 38 is attached to the end por~ion Qf bearn 10 by a central capscrew 42 which extends through beam hole 34 and a corresponding hole 44 formed in bracket vertical wall 36 to engage with a nut 45 and by a pair of longer capscrews 46 which extend through beam hoies 35 and corresponding I holes 47 to engage with nuts 49. T-bracket 38 also includes a plurality of hooks 48 which engage within vertically aligned, correspondingly spaced apart slots 50 formed in each of the four sides of a hollow block 52. Block 52 is in turn coupled between the adjacent end portions of vertical columns 54 by coupler members i 56 each of which can be composed of an open square shaped plug portion 58 which slidably engages within a correspondingly shaped socket, not shown, formed in each end portion of column 54, and a circular stud 60 which slidably engages within a central hole 52 provided in each end of block SZ. Thus, once T-bracket 38 has been bolted or otherwise fastened to the end portion of beam 10, the beam can be quickly, and con-veniently assembled with column(s) 54 by simply engaging hooks 48 in~o block slots 50.
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..s illustra~ed in FIG. 1, beams 10 can be overlayed by a floor panel 63 which leaves the beams exposed from below. Because of their pleasing and decorative appearance, beams 10 do no~ have to be covered by, or encased wit;hin plaster, gypswn board, paneling or other interior building materials, thus resulting in an economical, attractive construction.
It will be appreciated that beams 10 can be attached to columns 52 in other ways. Furthermore, beam 10 can function as a floor or a ceiling jois-t wherein i-ts ends are attached to a transversely extending headers or beams.
FIG. 4 illustrates an alternative ~ypical embodiment of the present invention wherein a fla~
reinforcing plate 64 is sandwiched between, and bonded to, central panels lla to increase the width of the beam web portion, and thus the section modulus of beam 110, to thereby enable the beam to carry an increased load over the load which can be safely carried by beam 10. Preferably plate 6~ stretches the full length of beam 110, and extends vertically from the lower surface of upper chord 124 to the upper surface of lower chord 130, to thus additionally support the two chords~ To compensate for the greater width separa-ting upper vertical panels 122 from each other and lower vertical panels 12B from each other due to the addition of the reinforcement plate 6/, the width of upper and lower chords 124 and 130, respec~ively, are increased by ~he thickness of plate 64. O~her than the addition of plate 64, the manner of constructing and assemblin~ beam 110 is essentially the same as tha~ of beam 10.
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: ~lthough plate 64 can be formed from a single ; thickness of woo~en material, prefe~ably it is constructed from a plurality of very thin wooden sheets, ideally approximately 1.0 mm thick, bonded together with a suitable adhesive, such as phenolaldehydel resin, in a manner similar to the fabrication of beam halves 16. The thickness of plate 64 can be selectively varied to alter the level of load which can be safely carried by beam 110. As the thickness of plate 64 is varied, the only adjustments which must be made to beam 110 is altering the width separating flange panels 122, and 128 and the thickness of chords 124 and 130.
A further typical embodimen~ oE the presen~
invention is illustrated in FIG. 5, wherein beam 210 I is constructed and dimensioned similarly to beam 10 illustrated in FIG. 3, with the exception that upper panels 220 are disposed horizontally to underlie upper chord member 224 rather than being disposed di.agonally in the manner of upper panels 20. Lil:ewise, lower : panels 226 are disposed horizontally to overlie the upper surface of lower chord member 230 rather than at a diagonal orientation in the manner of lower panel !
26, FIG. 3. In another difference between beams 10 and 210, the upper flange portion 219 of each beam . half 216 includes a top horizontal panel 266 which extends transversely inwardly from a correspondin~
upper edge of vertical panel 222 to abut against the top horizontal panel 266 of opposite beam halE 21G
at the vertical l:ine of symmetry VS of beam 10. Likewise, each beam half lower flan~e portion 225 includes a '' ' ~ 18~
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. bottom horizontal panel 26~ which extends transversely inwardly - from the lower edge portion of vertical panel 230 to abut against the bottom horizontal panel 268 of the opposite beam half 216 at the vertical line of symmetry VS of beam 10.
By constructing beam halves 216 in the manner described above, the flange upper portions 219 define a rectangularly shaped cavity for receiving a closely fitting, rectangularly shaped chord member 224. Likewise, the lower flange portion 225 of beam halves 216 form a cavity having a rectangular cross section for snugly receiving a rectangularly shaped, lower chord member : 230. By encasing upper chord 226 and lower chord 230 in this manner, only the outer surface of beam halves 216 are visible. This particular construction enables beam halves 216 to be formed with an outer cosmetic layer of mahogany, oak or similar wGod to ~ive beam 210 a highly decorative appearance. As a consequence, beam 210 can be left exposed rather than being covered with additional building materials.;
One further typical embodiment of Lhe present invention is illustrated in FIG. 6, whérein beam 310 is construc~ed similarly to beam 210 illustrated in FIG. 5, with the exception that a flat reinforcing plate 370 is sandwiched between central panels 318 to thereby enlarge the load carrying capacity of the beam by increasing its section modulus. Ideally, reinforcing plate 370 extends the full length of beam 310 and also extends vertically from the lower surface of upper chord member 324 to the upper surface of lower chord.330 to thereby reinforce the two chords.
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To accommodate the addition of reinforcing pla~e 370, the width of horizontal panels 372 and 320 of upper flange portion 319 are widened by half the thickness of pla~e 370. Likewise, the width of horizontal panels 326 and 374 of lower flange portion 3Z5 are enlarged by half the thickness of plate 370. Also, the width of upper chord member 324 and lo~ler chord member 330 are increased by the thickness of plate 370.
- As with reinforcing plate 64, illustrated in FIG. 4, plate 370 can also be forrned from a single thickness of wooden material; however, ideally, plate 370 is constructed from a plurali~y of very ~hin wooden . sheets each ideally about 1.0 mm thick bonded together with a sui~able adhesive, such as phenolaldehyde resin.
The thickness of plate 370 can be selective.ly altered in response to the load to be carried by the plate, 7 ~ ' with the only required change to the components of ~ beam 310 is the altering of the widt.h of flan~e panels 372, 374, 320 and 326 and the thickness of chords 324 and 330. Also the thickness of the laminations used to fabricate plate 370 can be changed to acco~nmodate the particular type of wood used tolconstruct the plate.
With the exception that plate 370 must be formed and then placed between central plates 318, the manner of constructing beam 310 is essen~ially identical to that of beam 210. Also beam 310 is assembled . with columns 54 in the same manner as is beam 10 as described above.
The invention may be embodied in other specific for ~ ~r embo~ nenes ~itho~t de~r~ from the ~pirit ~. . .~ I i or essential characteristics thereof. The typical embodiments of structural beams, described above, are therefor to be considered in all respects as illustrative and not restrictive. The scope of the invention is set forth in the appended claims rather than being limited to the specific typical en!bodiments of structural beams described in the foregoing description.
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Claims (5)
1 A wooden structural beam comprising:
an elongate upper chord member;
an elongate lower chord member; and two oppositely shaped halves disposed in side-by-side relationship to each other, each half including an elongate, flat central panel bonded to the central panel of the opposite half to form the web portion of said beam, an integral, formed upper edge portion extending upwardly and transversely outwardly from a corresponding central panel, said upper edge portions of said beam halves co-operating together to define an upwardly open trough between them for snugly receiving said upper chord member for forming the upper flange portion of said beam, and an integral, formed lower edge portion extending downwardly and trans-versely outwardly from each central panel, said lower edge portions of said beam halves cooperating together to define a downwardly open trough therebetween for snugly receiving said lower chord member for forming the lower flange portion of said beam;
wherein each end of said beam includes portions defining a slot extending vertically through, and longi-tudinally inwardly from, each of said beams.
an elongate upper chord member;
an elongate lower chord member; and two oppositely shaped halves disposed in side-by-side relationship to each other, each half including an elongate, flat central panel bonded to the central panel of the opposite half to form the web portion of said beam, an integral, formed upper edge portion extending upwardly and transversely outwardly from a corresponding central panel, said upper edge portions of said beam halves co-operating together to define an upwardly open trough between them for snugly receiving said upper chord member for forming the upper flange portion of said beam, and an integral, formed lower edge portion extending downwardly and trans-versely outwardly from each central panel, said lower edge portions of said beam halves cooperating together to define a downwardly open trough therebetween for snugly receiving said lower chord member for forming the lower flange portion of said beam;
wherein each end of said beam includes portions defining a slot extending vertically through, and longi-tudinally inwardly from, each of said beams.
2. A structural beam according to claim 1, wherein each end portion of said beam includes portions defining cross holes extending transversely through said beam web portion through said beam upper edge portion and said upper chord member, and said beam lower edge portion and its lower chord.
3. A structural beam according to claim 1 or 2, further comprising a flat, reinforcing plate sandwiched between said central panels of said two beam halves.
4. A wooden structural I-beam, comprising:
two oppositely shaped halves bonded together in side-by-side relationship, each of said halves composed of a plurality of very thin wooden laminations bonded together and molded to define:
a flat, vertical, horizontally elongate web panel;
first upper and lower transverse flange panels extending horizontally and transversely outwardly from the upper and lower edge portions, respectively, of said web panel, upper and lower vertical flange panels extending upwardly and downwardly, respectively, from an outer edge portion of a horizontal flange panel, and said web panels of said two beam halves bonded together in face-to-face relationship wherein said upper transverse flange panels and upper vertical panels co-operating together to form an upwardly open trough along the length of said beam, and said lower transverse panels and said lower vertical panels cooperating together to form a downwardly open trough extending the length of said beam;
an upper, horizontally elongate chord member snugly receivable within said upper trough; and a lower, horizontally elongate chord member snugly receivable within said lower trough;
said wooden structural I-beam further comprising a slot extending vertically through, and inwardly from each end of, said beam, and additionally comprising a hole extending transversely through said web panels of said two beam halves, a hole extending transversely through said upper and lower flange panels of said two beam halves and their corresponding upper and lower chord members, respectively.
two oppositely shaped halves bonded together in side-by-side relationship, each of said halves composed of a plurality of very thin wooden laminations bonded together and molded to define:
a flat, vertical, horizontally elongate web panel;
first upper and lower transverse flange panels extending horizontally and transversely outwardly from the upper and lower edge portions, respectively, of said web panel, upper and lower vertical flange panels extending upwardly and downwardly, respectively, from an outer edge portion of a horizontal flange panel, and said web panels of said two beam halves bonded together in face-to-face relationship wherein said upper transverse flange panels and upper vertical panels co-operating together to form an upwardly open trough along the length of said beam, and said lower transverse panels and said lower vertical panels cooperating together to form a downwardly open trough extending the length of said beam;
an upper, horizontally elongate chord member snugly receivable within said upper trough; and a lower, horizontally elongate chord member snugly receivable within said lower trough;
said wooden structural I-beam further comprising a slot extending vertically through, and inwardly from each end of, said beam, and additionally comprising a hole extending transversely through said web panels of said two beam halves, a hole extending transversely through said upper and lower flange panels of said two beam halves and their corresponding upper and lower chord members, respectively.
5. A wooden structural I-beam according to claim 4, wherein each beam half includes a second upper transverse flange panel extending horizontally and transversely inwardly from the upper edge portion of a corresponding upper vertical flange panel, said second upper transverse flange panels of said two beam halves substantially completely overlying the upper surface of said upper chord member; and a second lower transverse flange panel extending transversely and horizontally inwardly from the lower edge portion of a corresponding lower vertical flange panel, said second lower transverse flange panel of said two beam halves substantially completely underlying the lower surface of said lower chord member.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000354748A CA1139518A (en) | 1980-06-25 | 1980-06-25 | Structural beam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000354748A CA1139518A (en) | 1980-06-25 | 1980-06-25 | Structural beam |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1139518A true CA1139518A (en) | 1983-01-18 |
Family
ID=4117257
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000354748A Expired CA1139518A (en) | 1980-06-25 | 1980-06-25 | Structural beam |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1139518A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4843777A (en) * | 1987-01-13 | 1989-07-04 | Yoshinobu Shimabukuro | Wooden synthetic beam |
-
1980
- 1980-06-25 CA CA000354748A patent/CA1139518A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4843777A (en) * | 1987-01-13 | 1989-07-04 | Yoshinobu Shimabukuro | Wooden synthetic beam |
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