EP2900881A1 - A metal web joist comprising at least one anchorage enhancer plate - Google Patents

A metal web joist comprising at least one anchorage enhancer plate

Info

Publication number
EP2900881A1
EP2900881A1 EP13765597.3A EP13765597A EP2900881A1 EP 2900881 A1 EP2900881 A1 EP 2900881A1 EP 13765597 A EP13765597 A EP 13765597A EP 2900881 A1 EP2900881 A1 EP 2900881A1
Authority
EP
European Patent Office
Prior art keywords
plate
anchorage
tooth
anchorage enhancer
joist
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.)
Withdrawn
Application number
EP13765597.3A
Other languages
German (de)
French (fr)
Inventor
Paul Baron
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.)
Illinois Tool Works Inc
Original Assignee
Illinois Tool Works Inc
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 Illinois Tool Works Inc filed Critical Illinois Tool Works Inc
Publication of EP2900881A1 publication Critical patent/EP2900881A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • 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
    • E04C3/29—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces built-up from parts of different material, i.e. composite structures
    • E04C3/291—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces built-up from parts of different material, i.e. composite structures with apertured web
    • 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
    • E04C3/18—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members with metal or other reinforcements or tensioning members
    • 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
    • E04C3/29—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces built-up from parts of different material, i.e. composite structures
    • E04C3/292—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces built-up from parts of different material, i.e. composite structures the materials being wood and metal
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B15/00—Nails; Staples
    • F16B15/0023—Nail plates
    • F16B15/003—Nail plates with teeth cut out from the material of the plate
    • F16B15/0046—Nail plates with teeth cut out from the material of the plate from the body of the plate

Definitions

  • the invention relates to a metal web joist or beam comprising at least one anchorage enhancer plate. More particularly, though not exclusively, the invention relates to a metal web joist or beam comprising a plurality of metal web members securable to a chord of the joist or beam, at least one of which metal web members is further securable to a chord of the joist or beam by way of at least one anchorage enhancer plate.
  • anchorage capacity is the resistance of a portion of a metal web member anchored to a chord of the joist or beam to its removal therefrom upon the application of force to the point(s) of anchorage.
  • the anchorage capacity of a metal web element is the amount of resistance provided to prevent the removal of the metal web element from the timber chord of the joist or beam to which the metal web element is anchored when loading forces are applied to the metal web element.
  • the anchorage capacity of a metal web element is exceeded, the anchorage of the metal web element to the chord of the joist or beam will fail at the point(s) of anchorage.
  • Metal web joists are typically formed of an upper and a lower timber chord in parallel and spaced apart relation to one another.
  • the upper and lower chords are linked together and maintained in spaced apart relation by one or more metal web members.
  • The, or each, metal web member comprises a first and a second nail plate, linked together and spaced apart from one another by an elongate bracing member.
  • anchorage of the, or each, metal web member to the upper and lower timber chords is provided by integral nails or teeth in the nail plates of the metal web member.
  • the nail plates are typically securable to the side surfaces of the upper and lower timber chords thereby securing the metal web member to the timber chords.
  • the anchorage capacity of such a metal web joist is the amount of resistance provided to prevent the removal of the metal web element from the timber chord of the joist or beam to which the metal web element is anchored when loading forces are applied to the metal web element.
  • the greater the number of nails in the, or each, nail plate the greater the anchorage capacity.
  • Each nail plate has a number of nails formed integrally therewith. The number of nails formed from each nail plate is proportional to the length of the nails formed. For example, there will be fewer longer nails than shorter nails as the number of nails is defined by the surface area of the nail plate itself from which the nails are formed. The number of nails is limited to the amount of material in the nail plate insofar as there needs to be sufficient material left in the planar portion of the nail plate to resist breakage and/or shear in the nail plate.
  • the anchorage capacity required at each point on a joist or beam in any given application may be calculated.
  • the anchorage capacity of one metal web member is insufficient for the given application, it is typical to provide a further metal web member in close proximity to the first metal web member in the joist or beam so as to provide enhanced anchorage capacity in that area of the joist or beam. This may lead to a situation wherein more anchorage capacity is provided than is adequate to the application and requires greater material to be used in the metal web members than is required to provided the necessary anchorage capacity in the joist or beam.
  • the present invention provides a joist comprising an upper and a lower timber chord in parallel and spaced apart relation to one another, the upper and lower chords being linked together and maintained in spaced apart relation by one or more metal web members, the, or each, metal web member comprises a first and a second nail plate, linked together and spaced apart from one another by an elongate bracing member, each nail plate comprising integral nails whereby the nail plates are each securable to a surface of one of the upper and lower timber chords thereby securing the metal web member to the timber chords, wherein at least one of said first and second nail plates is further secured to the upper or the lower timber chord by at least one anchorage enhancer plate.
  • each nail plate is secured to a side surface of one of the upper and lower timber chords.
  • the at least one anchorage enhancer plate comprises a substantially planar plate portion and at least two teeth depending from a surface of the planar plate portion and being formed integrally therewith. More specifically, the at least one anchorage enhancer plate may comprise at least four teeth depending from a surface of the planar plate portion and being formed integrally therewith.
  • the teeth of the anchorage enhancer plate are dimensioned to fit into predefined apertures in the or each nail plate of the metal web member. More specifically, the teeth of the anchorage enhancer plate may be dimensioned to fit into the apertures in the nail plate formed when the integral nails of the nail plate are themselves formed.
  • the anchorage enhancer plate is a substantially rectangular plate having a thickness dimension of approximately 2mm.
  • the anchorage enhancer plate may be formed of steel or galvanised steel.
  • each tooth of the, or each, pair of teeth is located on the substantially planar plate portion in diagonal relation to the other tooth of the same pair.
  • each tooth is formed by pressing, punching or stamping same from the material of the substantially planar plate portion so as to be raised from the plane including the substantially planar plate portion.
  • each tooth remains attached to the material of the substantially planar plate portion at the base of the tooth so formed such that the tooth remains integral with the material of the substantially planar portion of the anchorage enhancer plate.
  • the, or each, tooth of the anchorage enhancer plate is raised substantially perpendicularly from the plane including the substantially planar portion.
  • the, or each, tooth of the anchorage enhancer plate is of a length which is longer than the nails of the, or each, nail plate of the metal web member. In embodiments, the, or each, tooth of the anchorage enhancer plate is of a length approaching 50% of the length of the substantially planar portion.
  • the, or each, tooth of the anchorage improver plate is up to 20mm in length. It has been found that providing teeth longer than 20mm, requires the thickness of the material of the substantially planar portion to be increased to provide a thicker diameter tooth to prevent buckling thereof when the anchorage enhancer plate is secured to a timber chord.
  • the joist comprises a plurality of anchorage enhancer plates.
  • the joist comprises a plurality of metal web members at least one of which is further secured to the upper and/or the lower chord of the joist by an anchorage enhancer plate.
  • a joist having at least one nail plate further secured to the upper and/or the lower chord of the joist by an anchorage enhancer plate according to the invention increases the anchorage capacity of the nail plate through which it is secured to the adjacent timber chord by 12% or more.
  • the present invention provides an anchorage enhancer plate comprising a substantially planar plate portion and at least two teeth depending from a surface of the plate portion and being formed integrally therewith.
  • the anchorage enhancer plate comprises at least four teeth depending from a surface of the plate portion and being formed integrally therewith. It is preferred that the teeth of the anchorage enhancer plate act as a unit as opposed to as individual fixing means and as a result the load applied to the anchorage enhancer plate is shared more evenly between the teeth of the unit than would be the case with individual fixing means, individual nails or screws for example.
  • the teeth of the anchorage enhancer plate as a unit as opposed to utilising individual fixing means, a user can be more confident in the anchorage capacity afforded by the anchorage enhancer plate.
  • Individual fixing means may be placed in any random location and orientation relative to the nail plate through which they are fixed to a timber chord and, as such, the position and load bearing of each individual fixing means cannot be guaranteed and measured with any consistency and accuracy.
  • the anchorage enhancer plate is a substantially rectangular plate having a thickness dimension of approximately 2mm.
  • the anchorage enhancer plate is formed of steel or galvanised steel.
  • each tooth of the, or each, pair of teeth is located on the substantially planar plate portion is diagonal relation to the other tooth of the same pair.
  • each tooth is formed by pressing, punching or stamping same from the material of the substantially planar plate portion so as to be raised from the plane including the substantially planar plate portion. More specifically, the tooth remains attached to the material of the substantially planar plate portion at the base of the tooth so formed such that the tooth remains integral with the material of the substantially planar portion of the anchorage enhancer plate.
  • each, tooth of the anchorage enhancer plate is raised substantially perpendicularly from the plane including the substantially planar portion.
  • the, or each, tooth of the anchorage enhancer plate is of a length approaching 50% of the length of the substantially planar portion. More specifically, the, or each, tooth of the anchorage enhancer plate is up to 20mm in length. It has been found that if the or each tooth is made longer than 20mm, the thickness of the material of the substantially planar portion would need to be increased to provide a thicker diameter tooth to prevent buckling thereof when the anchorage enhancer plate is secured to a timber chord.
  • Figure 1 shows an anchorage enhancer plate in accordance with an embodiment of the present invention
  • Figure 2 shows a side plan view of the anchorage enhancer plate of Figure 1
  • Figure 3 shows a top plan view of the anchorage enhancer plate of Figure 1;
  • Figure 4 shows a partial representation of a nail plate of a metal web member
  • Figure 5 shows a partial representation of a nail plate of a metal web member with the anchorage enhancer plate of Figure 1 mounted thereon;
  • Figure 6 shows a partial metal web joist comprising a number of metal web members secured thereto with one of said metal web members being further secured to the top chord of the joist by the anchorage enhancer plate of Figure 1.
  • an anchorage enhancer plate comprising four integral teeth.
  • an anchorage enhancer plate can be provided with any number of integral teeth which will, together, act as a unit in increasing the anchorage capacity of a metal web member and, specifically, a nail plate of a metal web member securable to a chord of a joist by the anchorage enhancer plate.
  • an anchorage enhancer plate 1 comprising a substantially planar, rectangular plate portion 3 and four teeth 5 depending from a surface 7 of the plate portion 3 and being formed integrally therewith.
  • the teeth 5 are each punched from the material of the planar plate portion 3 and are folded about their base so as to protrude from the planar plate portion 3 at right angles to the surface 7 of the plate 3.
  • nail apertures 9 are formed in the plate portion 3.
  • the planar plate portion 3 is formed of galvanised steel of 2mm thickness.
  • the teeth 5 are, therefore, of 2mm cross-sectional diameter.
  • the length of each of tooth 5 is determined by the longitudinal dimension of the plate portion 3.
  • each tooth 5 of the anchorage enhancer plate 1 is of a length approaching 50% of the length of the substantially planar portion 3.
  • each tooth 5 of the anchorage enhancer plate 1 may be up to 20mm in length.
  • the planar plate portion may be 58mm in length and 25mm in width thereby forming a rectangular anchorage enhancer plate 1.
  • the planar plate portion 3 is formed of 2mm thick galvanised steel.
  • the nail aperture 9 formed when each tooth 5 is punched from the material of the planar plate portion 3 measures 20mm in length and 2.83mm in width.
  • the distance between the centres of the two teeth on the same longitudinal axis of the planar plate portion 3 is 43mm.
  • each nail aperture 9 nearest a longitudinal edge of the planar plate portion 3 is spaced apart therefrom by a distance of 4.99mm.
  • the teeth 5 of the anchorage enhancer plate 1 act as a unit to resist forces applied to the plate 1 and, as such, are operable to enhance the anchorage capacity of a nail plate of a metal web member which is further secured to the chord of a metal web joist by the anchorage enhancer plate 1.
  • This is in preference to utilising individual fixing means as a result of the load being applied to the anchorage enhancer plate being shared more evenly between the teeth of the unit than would be the case with individual fixing means, individual nails or screws for example.
  • Figure 4 shows a nail plate 58 of a metal web member 56.
  • the nail plate 58 is attached to and spaced apart from a further nail plate (not shown) by a diagonal elongate bracing member 62.
  • the diagonal bracing element 62 comprises an elongate reinforcement rib 72 which provides additional strength and resistance to buckling to the elongate bracing element 62.
  • the nail plate 58 has a number of integral nails 64 punched from the material of the nail plate. The operation of punching out the nails 64 provides nail apertures 66 in the surface of the nail plate 58.
  • the length of each of the nails 64 is dependent upon the number of nails formed from the material of the nail plate 58. It will be understood that the greater the number of nails 64, the shorter in length each of those nails 64 will be.
  • Figure 5 depicts the anchorage enhancer plate 1 of Figures 1 to 3 mounted to the nail plate 58 of the metal web member 56 of Figure 4.
  • Each of the integral teeth 5 of the anchorage enhancer plate 1 are dimensioned to fit through a nail aperture 66 in the nail plate 58.
  • Each of teeth 5 are of greater length dimension than the nails 64 of the nail plate 58.
  • the anchorage enhancer plate 1 is operable to increase the anchorage capacity of the nail plate 58.
  • Figure 6 depicts a metal web joist 50 according to the present invention.
  • the joist 50 comprises an upper timber chord 52 and a lower timber chord 54 in parallel and spaced apart relation to one another.
  • the upper and lower chords 52, 54 are linked together and maintained in spaced apart relation by a series of metal web members 56.
  • Each metal web member 56 comprises a first 58 and a second 60 nail plate, linked together and spaced apart from one another by a diagonal elongate bracing member 62.
  • Each nail plate 58, 60 comprises a plurality of integral nails 64 whereby the nail plates 58, 60 are each securable to the side surfaces (53a, 55a) of one of the upper 52 and lower 54 timber chords thereby securing each metal web member 56 to the timber chords.
  • the joist will have a measurable anchorage capacity. That is to say, each nail plate 58, 60 will resist its separation from the timber chord to which it is attached until a force of predetermined magnitude and location is applied to the joist.
  • a nail plate 58a is attached to the side surface 53a of the upper timber chord 52 by integral nails (not shown).
  • the nail plate 58a is further secured to the side surface 53a of the upper timber chord 52 by anchorage enhancer plate 1.
  • the integral teeth (not shown) of the anchorage enhancer plate 1 are passed through the nail apertures 66 of the nail plate 58a into the side surface 53a of the chord 52.
  • the anchorage capacity of the nail plate 58a is enhanced by the anchorage enhancer plate 1 such that the resistance of the combined nail plate 58a and anchorage enhancer plate 1 to separation from the timber chord 52 is increased above the anchorage capacity provided by nail plate 58a alone.
  • the nail plate 58a further secured to the upper chord of the joist by the anchorage enhancer plate 1 according to the invention increases the anchorage capacity of the nail plate 58a through which it is secured to the adjacent timber chord by 12% or more.
  • nail plates 58, 58a of Figure 6 may be further .a iired to the timber chords 52, 54 by further anchorage enhancer plates [hot shown ⁇ .
  • the anchorage enhancer plate may be formed from any suitable material of any suitable thickness.
  • the plate may be formed of 1mm, 1.2mm or 2mm thickness galvanised steel. Thicker steel may be utilised in applications wherein heavier loads are envisaged.
  • the anchorage enhancer plate may be of any suitable dimensions.
  • the anchorage enhancer plate may be of any suitable footprint.
  • the anchorage enhancer plate may be, for example, rectangular, square, circular, triangular, polygonal or any other shape whatsoever.
  • the anchorage enhancer plate may comprise any number of teeth.
  • the number of teeth provided in the anchorage enhancer plate will be determined by the dimension of the plate. The greater the number of teeth provided, the greater the increase in anchorage capacity provided by the anchorage enhancer plate when a nail plate of determinable anchorage capacity is further secured to a joist or beam by the anchorage enhancer plate of the invention.
  • the teeth of the anchorage enhancer plate are preferably of greater length than the integral nails of the nail plate which is further secured to a joist or beam by the anchorage enhancer plate.

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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)
  • Chemical & Material Sciences (AREA)
  • Composite Materials (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Joining Of Building Structures In Genera (AREA)
  • Floor Finish (AREA)

Abstract

The invention relates to a joist comprising an upper and a lower timber chord in parallel and spaced apart relation to one another, the upper and lower chords being linked together and maintained in spaced apart relation by one or more metal web members, the, or each, metal web member comprises a first and a second nail plate, linked together and spaced apart from one another by an elongate bracing member, each nail plate comprising integral nails whereby the nail plates are each securable to the side surfaces of one of the upper and lower timber chords thereby securing the metal web member to the timber chords, wherein at least one of said first and second nail plates is further secured to the upper and lower timber chords by at least one anchorage enhancer plate.

Description

W
A METAL WEB JOIST COMPRISING AT LEAST ONE ANCHORAGE ENHANCER PLATE
The invention relates to a metal web joist or beam comprising at least one anchorage enhancer plate. More particularly, though not exclusively, the invention relates to a metal web joist or beam comprising a plurality of metal web members securable to a chord of the joist or beam, at least one of which metal web members is further securable to a chord of the joist or beam by way of at least one anchorage enhancer plate. In metal web joists or beams, anchorage capacity is the resistance of a portion of a metal web member anchored to a chord of the joist or beam to its removal therefrom upon the application of force to the point(s) of anchorage. Thus, the anchorage capacity of a metal web element is the amount of resistance provided to prevent the removal of the metal web element from the timber chord of the joist or beam to which the metal web element is anchored when loading forces are applied to the metal web element. When the anchorage capacity of a metal web element is exceeded, the anchorage of the metal web element to the chord of the joist or beam will fail at the point(s) of anchorage.
Metal web joists are typically formed of an upper and a lower timber chord in parallel and spaced apart relation to one another. The upper and lower chords are linked together and maintained in spaced apart relation by one or more metal web members. The, or each, metal web member comprises a first and a second nail plate, linked together and spaced apart from one another by an elongate bracing member. Typically, in metal web joists, anchorage of the, or each, metal web member to the upper and lower timber chords is provided by integral nails or teeth in the nail plates of the metal web member. The nail plates are typically securable to the side surfaces of the upper and lower timber chords thereby securing the metal web member to the timber chords. The anchorage capacity of such a metal web joist is the amount of resistance provided to prevent the removal of the metal web element from the timber chord of the joist or beam to which the metal web element is anchored when loading forces are applied to the metal web element. Typically, the greater the number of nails in the, or each, nail plate, the greater the anchorage capacity. Each nail plate has a number of nails formed integrally therewith. The number of nails formed from each nail plate is proportional to the length of the nails formed. For example, there will be fewer longer nails than shorter nails as the number of nails is defined by the surface area of the nail plate itself from which the nails are formed. The number of nails is limited to the amount of material in the nail plate insofar as there needs to be sufficient material left in the planar portion of the nail plate to resist breakage and/or shear in the nail plate.
The anchorage capacity required at each point on a joist or beam in any given application may be calculated. In circumstances wherein the anchorage capacity of one metal web member is insufficient for the given application, it is typical to provide a further metal web member in close proximity to the first metal web member in the joist or beam so as to provide enhanced anchorage capacity in that area of the joist or beam. This may lead to a situation wherein more anchorage capacity is provided than is adequate to the application and requires greater material to be used in the metal web members than is required to provided the necessary anchorage capacity in the joist or beam.
It is desirable to increase the anchorage capacity of a metal web member of a metal web joist to prevent the nail plates of the member peeling away from the timber chord to which it is attached under stress from loads applied to the joist.
It is an object of the present invention to enhance the anchorage capacity of at least one metal web member of a metal web joist.
Summary of the Invention
According to a first aspect, the present invention provides a joist comprising an upper and a lower timber chord in parallel and spaced apart relation to one another, the upper and lower chords being linked together and maintained in spaced apart relation by one or more metal web members, the, or each, metal web member comprises a first and a second nail plate, linked together and spaced apart from one another by an elongate bracing member, each nail plate comprising integral nails whereby the nail plates are each securable to a surface of one of the upper and lower timber chords thereby securing the metal web member to the timber chords, wherein at least one of said first and second nail plates is further secured to the upper or the lower timber chord by at least one anchorage enhancer plate. In certain arrangements, each nail plate is secured to a side surface of one of the upper and lower timber chords.
In embodiments of the invention, the at least one anchorage enhancer plate comprises a substantially planar plate portion and at least two teeth depending from a surface of the planar plate portion and being formed integrally therewith. More specifically, the at least one anchorage enhancer plate may comprise at least four teeth depending from a surface of the planar plate portion and being formed integrally therewith.
It is preferable that the teeth of the anchorage enhancer plate are dimensioned to fit into predefined apertures in the or each nail plate of the metal web member. More specifically, the teeth of the anchorage enhancer plate may be dimensioned to fit into the apertures in the nail plate formed when the integral nails of the nail plate are themselves formed. In embodiments, the anchorage enhancer plate is a substantially rectangular plate having a thickness dimension of approximately 2mm.
The anchorage enhancer plate may be formed of steel or galvanised steel. In embodiments, each tooth of the, or each, pair of teeth is located on the substantially planar plate portion in diagonal relation to the other tooth of the same pair.
In embodiments, each tooth is formed by pressing, punching or stamping same from the material of the substantially planar plate portion so as to be raised from the plane including the substantially planar plate portion. Preferably, each tooth remains attached to the material of the substantially planar plate portion at the base of the tooth so formed such that the tooth remains integral with the material of the substantially planar portion of the anchorage enhancer plate. In embodiments, the, or each, tooth of the anchorage enhancer plate is raised substantially perpendicularly from the plane including the substantially planar portion.
In preferred embodiments, the, or each, tooth of the anchorage enhancer plate is of a length which is longer than the nails of the, or each, nail plate of the metal web member. In embodiments, the, or each, tooth of the anchorage enhancer plate is of a length approaching 50% of the length of the substantially planar portion.
More specifically, the, or each, tooth of the anchorage improver plate is up to 20mm in length. It has been found that providing teeth longer than 20mm, requires the thickness of the material of the substantially planar portion to be increased to provide a thicker diameter tooth to prevent buckling thereof when the anchorage enhancer plate is secured to a timber chord. In embodiments, the joist comprises a plurality of anchorage enhancer plates.
In embodiments, the joist comprises a plurality of metal web members at least one of which is further secured to the upper and/or the lower chord of the joist by an anchorage enhancer plate.
In embodiments, a joist having at least one nail plate further secured to the upper and/or the lower chord of the joist by an anchorage enhancer plate according to the invention increases the anchorage capacity of the nail plate through which it is secured to the adjacent timber chord by 12% or more.
According to a second aspect, the present invention provides an anchorage enhancer plate comprising a substantially planar plate portion and at least two teeth depending from a surface of the plate portion and being formed integrally therewith. In preferred embodiments, the anchorage enhancer plate comprises at least four teeth depending from a surface of the plate portion and being formed integrally therewith. It is preferred that the teeth of the anchorage enhancer plate act as a unit as opposed to as individual fixing means and as a result the load applied to the anchorage enhancer plate is shared more evenly between the teeth of the unit than would be the case with individual fixing means, individual nails or screws for example. By providing the teeth of the anchorage enhancer plate as a unit as opposed to utilising individual fixing means, a user can be more confident in the anchorage capacity afforded by the anchorage enhancer plate. Individual fixing means may be placed in any random location and orientation relative to the nail plate through which they are fixed to a timber chord and, as such, the position and load bearing of each individual fixing means cannot be guaranteed and measured with any consistency and accuracy.
In certain embodiments the anchorage enhancer plate is a substantially rectangular plate having a thickness dimension of approximately 2mm.
In certain embodiments, the anchorage enhancer plate is formed of steel or galvanised steel.
In certain embodiments, each tooth of the, or each, pair of teeth is located on the substantially planar plate portion is diagonal relation to the other tooth of the same pair.
In is preferred that each tooth is formed by pressing, punching or stamping same from the material of the substantially planar plate portion so as to be raised from the plane including the substantially planar plate portion. More specifically, the tooth remains attached to the material of the substantially planar plate portion at the base of the tooth so formed such that the tooth remains integral with the material of the substantially planar portion of the anchorage enhancer plate.
In certain embodiments the, or each, tooth of the anchorage enhancer plate is raised substantially perpendicularly from the plane including the substantially planar portion.
In embodiments of the invention, the, or each, tooth of the anchorage enhancer plate is of a length approaching 50% of the length of the substantially planar portion. More specifically, the, or each, tooth of the anchorage enhancer plate is up to 20mm in length. It has been found that if the or each tooth is made longer than 20mm, the thickness of the material of the substantially planar portion would need to be increased to provide a thicker diameter tooth to prevent buckling thereof when the anchorage enhancer plate is secured to a timber chord.
Brief Description of the Drawings
Preferred embodiments of the present invention will now be described, by way of example only and not in any limitative sense, with reference to the accompanying drawings, in which: Figure 1 shows an anchorage enhancer plate in accordance with an embodiment of the present invention;
Figure 2 shows a side plan view of the anchorage enhancer plate of Figure 1; Figure 3 shows a top plan view of the anchorage enhancer plate of Figure 1;
Figure 4 shows a partial representation of a nail plate of a metal web member;
Figure 5 shows a partial representation of a nail plate of a metal web member with the anchorage enhancer plate of Figure 1 mounted thereon; and
Figure 6 shows a partial metal web joist comprising a number of metal web members secured thereto with one of said metal web members being further secured to the top chord of the joist by the anchorage enhancer plate of Figure 1.
Preferred embodiments of the invention will now be described by way of example only and in relation to an anchorage enhancer plate comprising four integral teeth. It should be appreciated that an anchorage enhancer plate can be provided with any number of integral teeth which will, together, act as a unit in increasing the anchorage capacity of a metal web member and, specifically, a nail plate of a metal web member securable to a chord of a joist by the anchorage enhancer plate.
Like reference numerals will be used throughout the figures to depict like features. Referring to Figures 1 to 3, there is depicted an anchorage enhancer plate 1 comprising a substantially planar, rectangular plate portion 3 and four teeth 5 depending from a surface 7 of the plate portion 3 and being formed integrally therewith. The teeth 5 are each punched from the material of the planar plate portion 3 and are folded about their base so as to protrude from the planar plate portion 3 at right angles to the surface 7 of the plate 3. During the punching operation forming teeth 5, respectively nail apertures 9 are formed in the plate portion 3. The planar plate portion 3 is formed of galvanised steel of 2mm thickness. The teeth 5 are, therefore, of 2mm cross-sectional diameter. The length of each of tooth 5 is determined by the longitudinal dimension of the plate portion 3. During the operation of forming teeth 5, sufficient planar plate material must remain to provide structural integrity to the anchorage enhancer plate 1 in use thereof. There must be sufficient planar steel material remaining in the formed anchorage enhancer plate to resist breakage under shear forces applied to the plate in use.
In the depicted embodiment of the invention, each tooth 5 of the anchorage enhancer plate 1 is of a length approaching 50% of the length of the substantially planar portion 3. In an exemplary embodiment, each tooth 5 of the anchorage enhancer plate 1 may be up to 20mm in length.
In a specific arrangement, depicted in Figures 2 and 3, the planar plate portion may be 58mm in length and 25mm in width thereby forming a rectangular anchorage enhancer plate 1. In such an arrangement, the planar plate portion 3 is formed of 2mm thick galvanised steel. There are four teeth 5 punched out of the material of the planar plate portion 3 and each protruding below the rear surface 7 of the planar plate portion 3 by 18mm in length. The nail aperture 9 formed when each tooth 5 is punched from the material of the planar plate portion 3 measures 20mm in length and 2.83mm in width. The distance between the centres of the two teeth on the same longitudinal axis of the planar plate portion 3 is 43mm. The distance between the centres of the two teeth on the same transverse axis of the planar plate portion 3 is 12.20mm. The longitudinal edge of each nail aperture 9 nearest a longitudinal edge of the planar plate portion 3 is spaced apart therefrom by a distance of 4.99mm.
The teeth 5 of the anchorage enhancer plate 1 act as a unit to resist forces applied to the plate 1 and, as such, are operable to enhance the anchorage capacity of a nail plate of a metal web member which is further secured to the chord of a metal web joist by the anchorage enhancer plate 1. This is in preference to utilising individual fixing means as a result of the load being applied to the anchorage enhancer plate being shared more evenly between the teeth of the unit than would be the case with individual fixing means, individual nails or screws for example.
Figure 4 shows a nail plate 58 of a metal web member 56. The nail plate 58 is attached to and spaced apart from a further nail plate (not shown) by a diagonal elongate bracing member 62. The diagonal bracing element 62 comprises an elongate reinforcement rib 72 which provides additional strength and resistance to buckling to the elongate bracing element 62. The nail plate 58 has a number of integral nails 64 punched from the material of the nail plate. The operation of punching out the nails 64 provides nail apertures 66 in the surface of the nail plate 58. The length of each of the nails 64 is dependent upon the number of nails formed from the material of the nail plate 58. It will be understood that the greater the number of nails 64, the shorter in length each of those nails 64 will be.
Figure 5 depicts the anchorage enhancer plate 1 of Figures 1 to 3 mounted to the nail plate 58 of the metal web member 56 of Figure 4. Each of the integral teeth 5 of the anchorage enhancer plate 1 are dimensioned to fit through a nail aperture 66 in the nail plate 58. Each of teeth 5 are of greater length dimension than the nails 64 of the nail plate 58. In this way, the anchorage enhancer plate 1 is operable to increase the anchorage capacity of the nail plate 58. Figure 6 depicts a metal web joist 50 according to the present invention. The joist 50 comprises an upper timber chord 52 and a lower timber chord 54 in parallel and spaced apart relation to one another. The upper and lower chords 52, 54 are linked together and maintained in spaced apart relation by a series of metal web members 56. Each metal web member 56 comprises a first 58 and a second 60 nail plate, linked together and spaced apart from one another by a diagonal elongate bracing member 62. Each nail plate 58, 60 comprises a plurality of integral nails 64 whereby the nail plates 58, 60 are each securable to the side surfaces (53a, 55a) of one of the upper 52 and lower 54 timber chords thereby securing each metal web member 56 to the timber chords. At each nail plate 58, 60 the joist will have a measurable anchorage capacity. That is to say, each nail plate 58, 60 will resist its separation from the timber chord to which it is attached until a force of predetermined magnitude and location is applied to the joist. In the depicted embodiment, a nail plate 58a is attached to the side surface 53a of the upper timber chord 52 by integral nails (not shown). The nail plate 58a is further secured to the side surface 53a of the upper timber chord 52 by anchorage enhancer plate 1. The integral teeth (not shown) of the anchorage enhancer plate 1 are passed through the nail apertures 66 of the nail plate 58a into the side surface 53a of the chord 52. The anchorage capacity of the nail plate 58a is enhanced by the anchorage enhancer plate 1 such that the resistance of the combined nail plate 58a and anchorage enhancer plate 1 to separation from the timber chord 52 is increased above the anchorage capacity provided by nail plate 58a alone.
In the depicted embodiment of Figure 6, the nail plate 58a further secured to the upper chord of the joist by the anchorage enhancer plate 1 according to the invention increases the anchorage capacity of the nail plate 58a through which it is secured to the adjacent timber chord by 12% or more.
In modifications to the depicted embodiment, it should be understood that some or all of the nail plates 58, 58a of Figure 6 may be further .a iired to the timber chords 52, 54 by further anchorage enhancer plates [hot shown}.
Various modifications are envisaged without departing from the scope of the invention and described and claimed. For example, the anchorage enhancer plate may be formed from any suitable material of any suitable thickness. For example, the plate may be formed of 1mm, 1.2mm or 2mm thickness galvanised steel. Thicker steel may be utilised in applications wherein heavier loads are envisaged.
The anchorage enhancer plate may be of any suitable dimensions. The anchorage enhancer plate may be of any suitable footprint. The anchorage enhancer plate may be, for example, rectangular, square, circular, triangular, polygonal or any other shape whatsoever. The anchorage enhancer plate may comprise any number of teeth. The number of teeth provided in the anchorage enhancer plate will be determined by the dimension of the plate. The greater the number of teeth provided, the greater the increase in anchorage capacity provided by the anchorage enhancer plate when a nail plate of determinable anchorage capacity is further secured to a joist or beam by the anchorage enhancer plate of the invention. The teeth of the anchorage enhancer plate are preferably of greater length than the integral nails of the nail plate which is further secured to a joist or beam by the anchorage enhancer plate.

Claims

Claims
A joist comprising an upper and a lower timber chord in parallel and spaced apart relation to one another, the upper and lower chords being linked together and maintained in spaced apart relation by one or more metal web members, the, or each, metal web member comprises a first and a second nail plate, linked together and spaced apart from one another by an elongate bracing member, each nail plate comprising integral nails whereby the nail plates are each securable to a surface of one of the upper and lower timber chords thereby securing the metal web member to the timber chords, wherein at least one of said first and second nail plates is further secured to the upper and lower timber chords by at least one anchorage enhancer plate.
A joist according to claim 1, wherein the at least one anchorage enhancer plate comprises a substantially planar plate portion and at least two teeth depending from a surface of the plate portion and being formed integrally therewith.
A joist according to claim 2, wherein the at least one anchorage enhancer plate comprises at least four teeth depending from a surface of the plate portion and being formed integrally therewith.
A joist according to any one of claims 1 to 3, wherein the anchorage enhancer plate is a substantially rectangular plate having a thickness dimension of 2mm.
A joist according to any one of claims 1 to 4, wherein the anchorage enhancer plate is formed of steel or galvanised steel.
A joist according to claim 2 or 3, wherein each tooth of the, or each, pair of teeth is located on the substantially planar plate portion is diagonal relation to the other tooth of the same pair.
A joist according to any one of claims 2 to 6, wherein each tooth is formed by pressing, punching or stamping same from the material of the substantially planar plate portion so as to be raised from the plane including the substantially planar plate portion.
A joist according to any one of claims 2 to 7, wherein the, or each, tooth of the anchorage enhancer plate is raised substantially perpendicularly from the plane including the substantially planar portion.
9. A joist according to any one of claims 2 to 8, wherein the, or each, tooth of the anchorage enhancer plate is of a length approaching 50% of the length of the substantially planar portion,
10. A joist according to claim 9, wherein the, or each, tooth of the anchorage enhancer plate is up to 20mm in length.
11. A joist according to any one of the preceding claims comprising a plurality of
anchorage enhancer plates.
12. A joist according to any one of the preceding claims comprising a plurality of metal web members at least one of which is further secured to the upper and/or the lower chord of the joist by an anchorage enhancer plate.
13. A joist according to any one of the preceding claims wherein the anchorage
enhancer plate increases the anchorage capacity of the nail plate through which it is secured to the adjacent timber chord by 12% or more.
14. An anchorage enhancer plate comprising a substantially planar plate portion and at least two teeth depending from a surface of the plate portion and being formed integrally therewith.
15. An anchorage enhancer plate according to claim 14, comprising at least four teeth depending from a surface of the plate portion and being formed integrally therewith
16. An anchorage enhancer plate according to claim 14 or claiml5, being a substantially rectangular plate having a thickness dimension of approximately 2mm.
17. An anchorage enhancer plate according to any one of claims 14 to 16, wherein the plate is formed of steel or galvanised steel.
18. An anchorage enhancer plate according to any one of claims 14 to 17, wherein each tooth of the, or each, pair of teeth is located on the substantially planar plate portion is diagonal relation to the other tooth of the same pair.
19. An anchorage enhancer plate according to any one of claims 14 to 16, wherein the, or each tooth is formed by pressing or stamping same from the material of the substantially planar plate portion so as to be raised from the plane including the substantially planar plate portion.
20. An anchorage enhancer plate according to claim 19, wherein the, or each, tooth remains attached to the material of the substantially planar plate portion at the base of the tooth so formed such that the tooth remains integral with the material of the substantially planar portion of the anchorage enhancer plate.
21. An anchorage enhancer plate according to claim 20, wherein the, or each, tooth is raised substantially perpendicularly from the plane including the substantially planar portion.
22. An anchorage enhancer plate according to any one of claims 14 to 21, wherein the, or each, tooth is of a length approaching 50% of the length of the substantially planar portion.
EP13765597.3A 2012-09-25 2013-09-10 A metal web joist comprising at least one anchorage enhancer plate Withdrawn EP2900881A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB1217098.1A GB2506198B (en) 2012-09-25 2012-09-25 Anchorage enhancer plate
PCT/US2013/059055 WO2014051997A1 (en) 2012-09-25 2013-09-10 A metal web joist comprising at least one anchorage enhancer plate

Publications (1)

Publication Number Publication Date
EP2900881A1 true EP2900881A1 (en) 2015-08-05

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Application Number Title Priority Date Filing Date
EP13765597.3A Withdrawn EP2900881A1 (en) 2012-09-25 2013-09-10 A metal web joist comprising at least one anchorage enhancer plate

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EP (1) EP2900881A1 (en)
GB (1) GB2506198B (en)
WO (1) WO2014051997A1 (en)

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US3304106A (en) * 1963-09-30 1967-02-14 Automated Building Components Truss and connector plates therefor
US3416283A (en) * 1966-11-03 1968-12-17 Sanford Arthur Carol Combination wood and metal trusses
US3708942A (en) * 1971-01-12 1973-01-09 F Leonard Roof trusses
US4031686A (en) * 1977-01-13 1977-06-28 Sanford Arthur C Combination wood and metal truss structure
US4359849A (en) * 1980-09-16 1982-11-23 W. R. Bonsal Company Insulated wall construction having a clip and fastener therein
US4485606A (en) * 1982-01-07 1984-12-04 Gang-Nail Systems, Inc. Truss structures constructed with metal web members
CA2226584A1 (en) * 1998-03-13 1999-09-13 Jan Vrana Composite structural member with sheet metal flanges
AUPS203902A0 (en) * 2002-04-30 2002-06-06 Mitek Industries, Inc. Framework and hold down connector

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Title
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Also Published As

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GB2506198A (en) 2014-03-26
GB2506198B (en) 2020-04-22
WO2014051997A1 (en) 2014-04-03
GB201217098D0 (en) 2012-11-07

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