Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
  • E04B1/18—Structures comprising elongated load-supporting parts, e.g. columns, girders, skeletons
  • E04B1/26—Structures comprising elongated load-supporting parts, e.g. columns, girders, skeletons the supporting parts consisting of wood
  • E04B1/2604—Connections specially adapted therefor
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
  • E04C3/00—Structural elongated elements designed for load-supporting
  • E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
  • E04C3/12—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members
  • E04C3/16—Joists; 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
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
  • E04B1/18—Structures comprising elongated load-supporting parts, e.g. columns, girders, skeletons
  • E04B1/26—Structures comprising elongated load-supporting parts, e.g. columns, girders, skeletons the supporting parts consisting of wood
  • E04B1/2604—Connections specially adapted therefor
  • E04B2001/2652—Details of nailing, screwing, or bolting
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B7/00—Roofs; Roof construction with regard to insulation
  • E04B7/02—Roofs; Roof construction with regard to insulation with plane sloping surfaces, e.g. saddle roofs
  • E04B7/04—Roofs; Roof construction with regard to insulation with plane sloping surfaces, e.g. saddle roofs supported by horizontal beams or the equivalent resting on the walls
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04D—ROOF COVERINGS; SKY-LIGHTS; GUTTERS; ROOF-WORKING TOOLS
  • E04D1/00—Roof covering by making use of tiles, slates, shingles, or other small roofing elements

Definitions

• the present invention concerns a joint for a truss structure between wooden construction members and a truss structure comprising such a joint.
• the purpose of the present invention is to reduce or overcome the deficiencies that are demonstrated within the prior-art technology and to achieve a joint for wooden construction members that has a high ability to absorb load, is reliable and allows large ranges for the constructions.
• the joint according to the invention makes it possible for greater loads to be absorbed by the joint in comparison with screw joints that are arranged perpendicular to the construction member.
• the ability of the screw joint to absorb axial loads is preserved in the joint according to the invention, in particular if the screw joints are arranged such that the load on the construction member and the joint influence the screw joint in the direction of withdrawal.
• This has the advantage that truss structures of wooden construction material that are joined by the joint according to the invention can support greater loads and can thus achieve greater ranges than previously.
• the joint according to the invention has the advantages also that truss structures can be built from fire- classified materials, are significantly cheaper and are not influenced by moist surroundings, in contrast with truss structures with joints manufactured from prestressed glued joints. Further distinctive features and advantages of the invention and its embodiments will be made clear by the non-independent claims and the following detailed description of preferred embodiments of the invention.
• Figure 1A shows a first embodiment of the invention in a side view.
• Figure lb shows in a cut-through side view of the embodiment shown in Figure la how the screw joints are assembled.
• Figure lc shows a cross-section through the joint shown in Figure la.
• Figure Id shows a view from above of the joint shown in Figure la.
• Figure 2 shows a truss structure of wooden construction members with joints according to the invention.
• Figure 3a shows a longitudinal view in section of the truss structure according to Figure 2.
• Figure 3b shows section A-A of the truss structure according to Figure 3a.
• Figure 3c shows section B-B of the truss structure according to Figure 3a.
• Figure 4 shows a truss structure of wooden construction members with a second embodiment of a joint according to the invention.
• Figures la-Id show a first embodiment of joint according to the invention between wooden construction members.
• the joint is intended to be used for, for example, a truss structure for a roof truss or similar building member (see Figure 2).
• the construction members are constituted by wooden beams, preferably glued laminated wooden beams whose direction of woodgrain is in accordance with the longitudinal direction of the beam.
• the joint is formed from two horizontal beams 1, 2 with a first direction of woodgrain, and an angled beam 3 with a second direction of woodgrain that differs from the first direction of woodgrain.
• the beams that form the joint are arranged in parallel planes.
• the horizontal beam may be a part of an upper or lower arm in a truss structure, and the angled beam represents a brace that joins the frames of such a truss structure.
• the directions between the horizontal beams with the first direction of woodgrain and the angled beam with the second direction of woodgrain differ by an angle ⁇ , where ⁇ is between 20° and 90°, preferably between 30° and 70°.
• the angle ⁇ is selected and adapted according to the location of the joint in the truss structure.
• the two horizontal beams 1, 2 are arranged parallel with their long sides 1.2 and 2.1 opposing each other.
• the angled beam 3 has a beam end 3.3 that is arranged between the two long sides of the two horizontal beams 1, 2 and that makes contact such that mutual contact surfaces Ml, M2 are formed between a region on one long side 3.1 of one beam and a region on the long side 1.2 of the horizontal beam 1 and between a region on the second long side 3.2 of the angled beam and a region on the long side 2.1 of the horizontal beam 2.
• the joint is further provided with several screw joints S(l)-S(n), (l)-R(n) that are assembled by being screwed through one of the horizontal wooden beams 1, 2 with the first direction of woodgrain and at least partially through the angled wooden beam 3 with the second direction of woodgrain.
• the screw joints S(l)-S(n), R(l)-R(n) join in this way the wooden beams that are in contact with each other along the contact surface Ml, M2 that is formed.
• the screw joints are distributed over the surface such that the load will be evenly distributed across the complete joint.
• the screw joints may be recessed into the horizontal wooden beam, or they may be screwed in without recessing.
• the load-bearing ability at each screw that is added to a previously distributed set or row of screws is reduced.
• the distance between the screw joints in the direction of woodgrain is to be increased such that the predetermined load is distributed across all screw joints.
• the joint according to the present invention demonstrates a set of screw joints distributed and mounted at the contact surface Ml, M2 of the joint and in the same direction as one of the directions of woodgrain without consideration being taken to reduction of the load-bearing ability at the relevant screw. This is achieved by mounting the screw joints with a shorter distance, i.e.
• the screw joints are mounted in the direction of the woodgrain with a distance between the screw joints that corresponds to approximately 5 times the screw diameter.
• the joint according to the invention with this distribution of screw joints has a good load-bearing ability that satisfies the requirements for supporting constructions.
• the distance between the screw joints in corresponding cases is prescribed to be approximately 10 times the screw diameter, which requires a significantly larger contact surface (Ml, M2).
• FIG. la-d The angled beam in Figures la-d is placed under load with a pressure force F T downwards along the direction of woodgrain.
• Figures la-d show that the screw joint, the screw S, is screwed in at an oblique angle a with the contact surface Ml (see Figure Id).
• the angle a corresponds to the angle between the contact surface and the screw.
• the corresponding angle ct arises between the screw S and the surface of the long side 1.1 of the horizontal beam.
• Figure lb shows that the screw joint is screwed in at the same direction as one of the directions of woodgrain, namely the direction of woodgrain of the angled beam.
• the screw is thus screwed into the horizontal beam at an angle ct with the contact surface Ml, and such that the axial direction of the screw essentially coincides with the direction of woodgrain of the angled beam and thus also with the direction of the load.
• the advantage of this is that when a load is applied along the direction of woodgrain of the angled beam, this load is absorbed in the axial direction of the screw.
• the screw S is in this case directed obliquely downwards in the same direction as the second direction of woodgrain through the horizontal beam and partially through the angled beam. It is in this way achieved that the axial load, the pressure force F T , which is directed downwards in the longitudinal direction at the angled beam, places the screw joint under tensile load in the axial direction of the screw.
• the joint according to the invention can in this way absorb larger loads, which means that a roof truss that is joined in this manner can be built with a larger range.
• the joint according to the invention means that the load- absorbing ability of the screw joint in the axial direction can be exploited and can be placed under a higher degree of load.
• the screws may be fully threaded or partially threaded.
• the screw joint may be mounted such that the screw head comes into contact with the surface of the long side of the horizontal beam or it may be recessed. The number of screw joints is selected and adapted to the calculated load on the joint.
• the screw joints S(l)-S(n), R(l)- (n) are mounted in the same direction as the direction of woodgrain of the angled beam 3" such that an axial load directed upwards along the length of the angled beam, i.e. a tensile force F D , instead places the screw joints under tensile load in the axial direction of the screws.
• the screw joints are mounted with an angle a to the contact surfaces Ml, M2 and in the same direction as the direction of the load F D , in this case in an upwards direction and essentially in the direction of woodgrain of the angled beam in the drawing.
• the screw joint may be mounted in the same direction as the direction of woodgrain of the angled beam such that an axial load, a tensile force directed upwards along the length of the angled beam, places the screw joint under compressive force in the axial direction of the screw.
• the screw joint in this case is thus mounted opposing the direction of the load, in such a case in a downwards direction and essentially in the direction of woodgrain of the angled beam in the drawing.
• the angle a between the axial direction of the screw and the contact surface Ml should be chosen to be between 10° and 70° from the surface, preferably between 20° and 40°. If the angle a is very small, the number of screws that can be mounted at the joint is limited, which reduces the load-bearing ability. If the angle is large, the desired effect of the load along the angled brace being absorbed by the axial direction of the screw is reduced.
• the screw joints S(l)-S(n) and the opposing screw joints R(l)-R(n) are screwed in such that opposing screws on each side of the angled beam 3 are distributed with a small displacement in order to avoid the screw joints S(l)-S(n) and the opposing screw joints R(l)-R(n) meeting in the angled beam.
• Figure lc and Figure Id show that several screw joints S(l)-S(n), R(l)-R(n) are screwed into the relevant horizontal beam 1, 2 with the first direction of woodgrain and partially through the angled beam 3.
• the screw joints S(l)-S(n) and the opposing screw joints R(l)-R(n) are angled at the angle a with the contact surface Ml and the contact surface M2, respectively, and are directed essentially along the direction of woodgrain of the angled beam as has been described above.
• the screw joints S(l)-S(n) interact with the opposing screw joints R(l)-R(n) in order to absorb the load.
• a second embodiment of the joint according to the invention comprises that the joint is further reinforced by joining the horizontal beams 1, 2 to the angled beam 3 by gluing the mutual contact surfaces Ml and M2 together, in order to form a glued joint before the screwing of the screw joints into the joint. This may be advantageous in certain applications when the surroundings and the construction member allow it.
• FIG. 2 shows a part of a truss structure 10 of wooden construction members.
• the truss structure comprises two joints Kl, K2 according to the invention. It is shown in the drawing that the joints Kl, K2 are arranged directly next to each other through the ends 3.3', 3.3" of the angled beams 3', 3" being designed to make contact with each other and to form a mutual contact surface M3.
• the joint Kl with the angled beam 3' is joined in order to absorb a pressure force F T that places of the angled beam 3' under load.
• the screw joints S(l)-S(n) and R(l)-R(n) are therefore screwed into the beam 3' directed obliquely downwards.
• the joint K2 with the angled beam 3" is joined in order to absorb a tensile force F D that places of the angled beam 3" under load.
• the screw joints S(l)-S(n) and R(l)-R(n) are therefore screwed into the beam 3" directed obliquely upwards.
• Figure 3a shows a longitudinal view in section of the truss structure, in which it is made more clear that the screw joints are screwed in along the direction of the angled beams 3' and 3".
• Figure 3b shows the section A-A of the truss structure according to Figure 3a, where the joint Kl is placed under a compressive force along the beam 3' and the screws are thus screwed at an angle a to the contact surface Ml, M2, obliquely downwards in a direction towards the contact surface M3.
• Figure 3c shows a section B-B of the truss structure according to Figure 3a where the joint K2 is placed under tensile load along the beam 3" and the screws are directed at an angle a with the contact surface Ml, M2 and obliquely upwards in the direction of woodgrain of the beam 3", in a corresponding manner.
• Figure 4 shows a part of a truss structure 20 of wooden construction members with a second embodiment of the joint according to the invention.
• This truss structure 20 comprises the joints PI and P2.
• the joint PI consists of a construction member 11, also known as a "frame part", with a first direction of woodgrain, and two construction members 13, 14 with a second direction of woodgrain that differs from the first direction of woodgrain.
• the two construction members 13, 14 are constituted by beams, also known as braces, with a second direction of woodgrain that is set at an angle ⁇ to the horizontal construction member 11 with the first direction of woodgrain.
• screw joints S(l)-S(n), (l)- (n) are mounted through the construction members 13, 14 with the second direction of woodgrain and at least partially through the construction member 11 with the first direction of woodgrain in order to unite the construction members and to form mutual contact surfaces Ml and M2 between the construction members.
• the screw joints are mounted at an oblique angle a to the contact surfaces Ml, M2.
• the screw joints are mounted at joint PI in the same direction as the direction of woodgrain of the angled beams 13, 14 in order to achieve a situation in which an axial load on an angled beam 13, 14 places its load on the screw joint in the axial direction of the screw.
• the joint PI is placed under an axial load, a pressure force F T , directed downwards along the longitudinal direction at the angled beam.
• the screws S in this case are therefore directed obliquely downwards in the same direction as the second direction of woodgrain through the angled beam 13 and partially through the horizontal beam 11. It is in this way achieved that the axial load, the pressure force F T , places the screw joint under tensile load in the axial direction of the screw.
• the joint P2 is placed under load in an opposing manner by an axially directed tensile force F D directed upwards along the length at the angled beam 13', 14', i.e. the force places the screw joints under tensile load in the axial direction of the screws, which screws have been screwed in obliquely upwards at an angle a to the contact surfaces Ml or M2 through the angled beams 13' and 14', and partially through the horizontal beam 11.
• F D axially directed tensile force directed upwards along the length at the angled beam 13', 14'
• the joint according to the invention By jointing the truss structure with the joint according to the invention both at joints that are subject to tensile forces and those that are subject to compressive forces, it is achieved that the load-bearing capacity of the truss structure is increased, which allows larger construction ranges. Furthermore, the joint according to the invention is simple and saves time, and thus also costs, during assembly.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Joining Of Building Structures In Genera (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=53371576

Family Applications (1)

Country Status (3)

Family Cites Families (7)

• 2013
  • 2013-12-12 SE SE1351491A patent/SE537689C2/sv unknown
• 2014
  • 2014-12-11 EP EP14870363.0A patent/EP3080362A4/de not_active Withdrawn
  • 2014-12-11 WO PCT/SE2014/051487 patent/WO2015088437A1/en active Application Filing

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