CA2180715C - Structural wooden joist - Google Patents

Structural wooden joist

Info

Publication number
CA2180715C
CA2180715C CA 2180715 CA2180715A CA2180715C CA 2180715 C CA2180715 C CA 2180715C CA 2180715 CA2180715 CA 2180715 CA 2180715 A CA2180715 A CA 2180715A CA 2180715 C CA2180715 C CA 2180715C
Authority
CA
Canada
Prior art keywords
chords
wooden joist
structural wooden
boards
short
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 - Fee Related
Application number
CA 2180715
Other languages
French (fr)
Other versions
CA2180715A1 (en
Inventor
Mario Labrie
Robert Veilleux
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to CA 2180715 priority Critical patent/CA2180715C/en
Priority to AU32522/97A priority patent/AU3252297A/en
Priority to PCT/CA1997/000478 priority patent/WO1998001636A1/en
Publication of CA2180715A1 publication Critical patent/CA2180715A1/en
Application granted granted Critical
Publication of CA2180715C publication Critical patent/CA2180715C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • EFIXED CONSTRUCTIONS
    • E04BUILDING
    • E04CSTRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C3/00Structural elongated elements designed for load-supporting
    • E04C3/02Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
    • E04C3/12Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members
    • E04C3/16Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members with apertured web, e.g. trusses

Landscapes

  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Rod-Shaped Construction Members (AREA)
  • Floor Finish (AREA)

Abstract

The structural wooden joist described comprises a lower chord, an upper chord spaced from the lower chord and an openwork web structure joining the chords. The web structure includes, between opposite ends thereof, a series of horizontally spaced trapezoidal laminated panels defining a series of triangular spacings therebetween; each panel has opposite short and long sides adhesively joined to the lower and upper chords respectively and each panel is formed of short obliquely extending boards adhesively secured edgewise to one another.

Description

~180'~1~
TITLE OF THE INVENTION
A structural wooden joist.
FIELD OF THE INVENTION
The present invention pertains to a structural wooden joist used in building constructions.
BACKGROUND OF THE INVENTION
Wooden joist are used increasingly in a number of building applications. They comprise top and bottom elongate chords with intervening struts joined to the chords by means of scarfing. One such 1o wooden joist may be found described in Canadian patent application 2,008,043 published July 18, 1991 to Lemyre.
Some web structures have a triangular configuration, such as the joists described in U. S. patent 4,228,631 issued October 21, 1980 to Geffe and Norwegian patent 112,944 granted May 6, 1968 to Greimbau-i5 Lizenz GmBH. However, these structures are produced from a plywood or other reconstituted grade wooden panels either disposed on either side of the chords or disposed vertically above another and interconnected by a structural member. These panels are usually glued and nailed to the chords.

__ ~18~~1 OBJECTS AND STATEMENT OF THE INVENTION
It is an object of the present invention to provide a novel wooden joist which consists in having a web structure wherein each panel is formed of short laminated boards which are adhesively secured to one another by gluing only thereby enabling an adjustment at the building location by a simple sawing operation.
The present invention therefore relates to a structural wooden joist which comprises:
a) an elongated lower chord;
io b) an elongated upper chord in a spaced apart generally parallel opposed relation to the lower chord;
c) an openwork web structure joining the chords; the web structure including, between opposite ends thereof, a series of horizontally spaced trapezoidal laminated 15 panels defining a series of triangular spacings therebetween; each panel having opposite short and long sides adhesively joined to the lower and upper chords respectively; each panel being formed of short obliquely extending boards adhesively secured edgewise to one 2 o another.
In one form of the invention, the short and long sides of the panel are secured to the chords by scarfing.
Preferably, the boards are made of kiln dry wood and selected from the group that includes fir, spruce and pine.
25 Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that this detailed description, while indicating preferred embodiments of the invention, is given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an elevational view of a wooden joist made in accordance with the present invention;
Figure 2 is a cross-sectional view taken along lines 2-2 of Figure 1;
~o Figure 3 is an elevational view of one trapezoidal panel used in the joist of figure 1;
Figure 4 is a side view thereof;
Figure 5 is an elevational view of an end panel of the joist of figure 1; and Figure 6 is an enlarged elevational view of two chords sections connected together.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to figure 1, there is shown a structural wooden joist, generally denoted 10, which comprises an elongated lower chord 12 and an 2 o upper chord 14 in spaced apart general ly parallel opposed relation to the lower chord 12. Between the upper and lower chords is provided an open work web structure consisting of a series of panels horizontally displayed between two opposite end panels 18 and 20.
Referring more particularly to figure 3, each panel 16 consists of a series of short obliquely extending boards 20, 22) 24, 26, 28 and 30 which are adhesively secured in an edgewise fashion to one another. The boards may also be formed of boards which are joined in an endwise manner by glue or scarfing.
The trapezoidal panel 16 has two opposite inclined edges 16a io and 16b, a short side 16c and a long side 16d. As can be seen in figure 4, the short side 16c and long side 16d have a finger sca~ng configuration.
Other connections can be used, such as those illustrated in U.S. patent No.
4,974,389 issued December 4, 1990 to Onysko or U.S. patent No. 5,267,425 issued December 7, 1993 also to Onysko i5 Referring to figure 5) the two opposite end panels 18 and 20 have an identical configuration which is a four-sided structure that includes, in the case of panel 18, an oblique side 18a and an opposite side 18b which is perpendicular to a short side 18c and long upper side 18d. Again) this panel is formed of a series of obliquely extending boards 32, 34, 36, 38) 40 2 o and 42 which are also adhesively secured to one another in an edgewise fashion. The opposite sides 18c and 18d also have a finger scarfing configuration similar to that of sides 16c and 16d of the panels 16.
All the boards used in the laminated panels 16) 18 and 20 are preferably disposed at an angle of 30°; other angles however may be used 2 s in accordance with configuration and/or height of the joist.
B

_ ~~ga7~~
Referring to figure 6, the elongated chords may consist of a series of chord sections (two being shown as 12a and 12b) which are again interconnected by means of finger scarfing and glued to one another in an endwise manner. Preferably, the chords are pre-cambered.
The wood used for all the boards of the panels is preferably kiln dry wood) selected from the group consisting of fir, spruce and pine.
Also, the adhesive used in securing the boards together as well as that used in the finger scarfing sections is a glue preferably having a base of resin resorcinol, such as phenol-resorcinol resin.
io Although the invention has been described above with respect with one specific form, it will be evident to a person skilled in the art that it may be modified and refined in various ways. It is therefore wished to have it understood that the present invention should not be limited in scope, except by the terms of the following claims.

Claims (10)

1. A structural wooden joist comprising:
a) an elongated lower chord;
b) an elongated upper chord in a spaced apart generally parallel opposed relation to said lower chord;
c) an openwork web structure joining said chords;
said web structure including, between opposite ends thereof, a series of horizontally spaced trapezoidal laminated panels defining a series of triangular spacings therebetween; each said panel having opposite short and long sides adhesively joined to said lower and upper chords respectively; each said panel being formed of short obliquely extending boards adhesively secured edgewise to one another.
2. A structural wooden joist as defined in claim 1, wherein said short and long sides of said panels are secured to said chords by scarfing.
3. A structural wooden joist as defined in claim 2, wherein said chords are substantially rectangular in cross-section.
4. A structural wooden joist as defined in claim 3, wherein each chord is formed of a series of successive boards joined horizontally by scarfing.
5. A structural wooden joist as defined in claim 1, wherein each said opposite ends of said web structure defines a laminated panel having horizontal top and bottom sides, an outer side extending perpendicularly to said chords and an inner side extending obliquely said chords; said panels of said opposite ends being formed of short obliquely extending boards adhesively secured edgewise to one another.
6. A structural wooden joist as defined in claim 5, wherein said boards are made of kiln dry wood.
7. A structural wooden joist as defined in claim 6, wherein said wood is selected from the group including fir, spruce and pine.
8. A structural wooden joist as defined in any one of claims 1 to 7 wherein said boards of said laminated panels extend at 30° with respect to said upper and lower chords.
9. A structural wooden joist as defined in any one on claims 1 to 7 wherein said boards are adhesively secured to one another by means of a glue having a base of resin resorcinol.
10. A structural wooden joist as defined in anyone of claims 1 to 7, wherein said lower chord is pre-cambered.
CA 2180715 1996-07-08 1996-07-08 Structural wooden joist Expired - Fee Related CA2180715C (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
CA 2180715 CA2180715C (en) 1996-07-08 1996-07-08 Structural wooden joist
AU32522/97A AU3252297A (en) 1996-07-08 1997-07-02 A structural wooden joist
PCT/CA1997/000478 WO1998001636A1 (en) 1996-07-08 1997-07-02 A structural wooden joist

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA 2180715 CA2180715C (en) 1996-07-08 1996-07-08 Structural wooden joist

Publications (2)

Publication Number Publication Date
CA2180715A1 CA2180715A1 (en) 1998-01-09
CA2180715C true CA2180715C (en) 1999-10-05

Family

ID=4158563

Family Applications (1)

Application Number Title Priority Date Filing Date
CA 2180715 Expired - Fee Related CA2180715C (en) 1996-07-08 1996-07-08 Structural wooden joist

Country Status (3)

Country Link
AU (1) AU3252297A (en)
CA (1) CA2180715C (en)
WO (1) WO1998001636A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI118378B (en) 2004-11-29 2007-10-31 Patenttitoimisto T Poutanen Oy Process for making one of woody parts with adhesive assembled joints
DE102009005102A1 (en) * 2009-01-19 2010-07-22 Binderholz Gmbh Holzindustrie Component and method for producing a component

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR419822A (en) * 1910-08-29 1911-01-16 Otto Hetzer Beams and other similar pieces of wood, arranged in compartments
US2444133A (en) * 1943-05-11 1948-06-29 Mid West Wood Products Company Building unit of generally right triangular form
FR984792A (en) * 1949-04-15 1951-07-10 Wooden beam composed of several boards glued together
DE903373C (en) * 1951-12-08 1954-02-04 Eerich A Falk Wooden beams or binders
FR1305199A (en) * 1961-11-13 1962-09-28 Truss beam
GB1367893A (en) * 1971-12-16 1974-09-25 Holme Sons Ltd Walter Structural beams
FR2246388A1 (en) * 1973-10-08 1975-05-02 Ion Corp Wooden construction frame component - comprises two planks with edges cut out and protrusions fitting together
US4228631A (en) * 1978-09-12 1980-10-21 Geffe Bruce T Hollow rectangular joist
US4356045A (en) * 1980-05-30 1982-10-26 St. Regis Paper Company Complete production line of wood I-joist manufacturing apparatus the method of manufacture, and the I-joist product, having lumber chords and a plywood web
CA2008043C (en) * 1990-01-18 1999-12-28 Rene Paul Lemyre Open joist
FR2669066A1 (en) * 1990-11-13 1992-05-15 Antignac Paul Device for stressing glued laminated wood beams - has two curved half-beams on adjustable platform to cater for two or more supports using chamber

Also Published As

Publication number Publication date
AU3252297A (en) 1998-02-02
CA2180715A1 (en) 1998-01-09
WO1998001636A1 (en) 1998-01-15

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Effective date: 20130709