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(11) | EP 2 607 561 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Improved hanger |
| (57) A joist hanger comprising: a support bracket, having a base portion and two substantially parallel side portions upstanding from opposing edges of said base portion; at least one back flange portion adjoining at least one of said two side portions at a longitudinal edge of respective at least one of said two side portions and adapted to abut a face-fixing surface; at least one top flange portion, adjoining said at least one back flange portion at an edge distal to said base portion and adapted to be moveable between a face-fixing position, wherein said top-flange portion is coplanar said at least one back flange portion, and a top-fixing position, wherein said top flange portion is non-coplanar to said at least one back flange portion, further comprising at least one longitudinally elongated fixing aperture and an articulation axis extending transversely of the hanger between the top flange portion and the back flange portion and being variable in location within the region defined by the length of said longitudinally elongated fixing aperture. |
[0001] The present invention relates to joist hangers used to connect two members such as I-joists, and in particular to multi-functional joist hangers that are adjustable to provide for variations in the size/shape of the connected members.
INTRODUCTION
[0002] The use of timber engineered structural components in the world is growing. I-joists, in particular, are used in floors, roof framing, wall framing and whole structural portal frames and roof trusses due to their high strength to weight ratio and associated advantageous characteristics when compared to traditional solid timber beams.
[0003] As shown in Figure 1 (a) and (b), an I-joist 1, 3 comprises two main parts, the web 5 and flanges 7, 9. The web 5 is sandwiched between a top 7 and bottom flange 9, creating the "I" shape. The flange 7, 9 can be made from laminated veneer lumber or solid wood finger-jointed together for ultimate strength. It is then grooved on one side to receive the web 5. The web 5 is typically made from plywood, laminated veneer lumber, or oriented strand board.
[0004] In house construction, for example, joist hangers are frequently used to typically connect two joists, or a joist with any other support structure, at a 90 degree angle. However, it may be required to connect the joists at any other desired angle. To form such a connection, the joist hanger is either face-fixed or top-fixed to the support provided by another joist or support structure.
[0005] For example, Figure 1 (a) shows two I-joists 1 and 3 connected at a 90 degree angle, wherein I-joist 1 is face-fixed to a side portion of I-joist 3 via a typical face-fix joist hanger 11. Face-fixing hangers are only fixed (e.g. nailed) to a side surface of the support via its side flanges 12. A bracket 13 connected to the side flanges 12 receives and supports joist 1, wherein the bracket is usually fixed to the joist flanges 14 and 15.
[0006] Figure 1 (b) shows two I-joists 1, 3 connected at a 90 degree angle, wherein I-joist 1 is top-fixed to I-joist 3 via a typical top-fix joist hanger 16. Top-fixing hangers comprise top flanges 18 that sit on a top surface 20 of the support structure, e.g. I-joist 3, with nails being passed through the top flange 18.
[0007] Top-fixing hangers, such as joist hanger 16, may be used for light/medium load applications using fewer fixings (e.g. nails) to allow a quick and easy installation. Face-fixing hangers, such as joist hanger 11, are often used for higher load applications using considerably more fixings (e.g. nails) making the installation more time consuming and expensive. Face-fixing hangers may also be used because it is simply impractical or undesirable to have a top flange 18 located on the top surface 20 of the support structure, e.g. I-joist 3.
[0008] Therefore, at least two types of hanger (such as joist hangers 11 and 16) are required to provide for face-fixing connections and top-fixing connections. Also, the top flange portion is pre-formed (L-shape or U-shape) and does not allow for any variations in joist depth, position or support joist width.
[0009] Accordingly, it is an object of the present invention to provide an improved joist hanger that can be used for face-fixing as well as top-fixing and that is adjustable within a range to joists of various shape and size without compromising the position accuracy and fixation location on the support structure.
[0010] It is a further object of the present invention to overcome one or more of the above disadvantages of the prior art.
SUMMARY OF THE INVENTION
[0011] According to a first aspect of the present invention, there is provided a joist hanger comprising:
a support bracket, having a base portion and two substantially parallel side portions upstanding from opposing edges of said base portion;
at least one back flange portion adjoining at least one of said two side portions at a longitudinal edge of respective at least one of said two side portions and adapted to abut a face-fixing surface;
at least one top flange portion, adjoining said at least one back flange portion at an edge distal to said base portion and adapted to be moveable between a face-fixing position, wherein said top flange portion is coplanar to said at least one back flange portion, and a top-fixing position, wherein said top flange portion is non-coplanar to said at least one back flange portion, further comprising at least one longitudinally elongated fixing aperture and an articulation axis extending transversely of the hanger between the top flange portion and the back flange portion and being variable in location within the region defined by the length of said longitudinally elongated fixing aperture.
[0012] By providing an articulation axis in the region of the hanger defined by the length of the longitudinally elongated aperture, in the top fixing position, at least one top fixing and at least one face fixing are locateable into a support structure through the elongated aperture. The support structure may be of variable depth dimension whilst still being suitable for attachment of the hanger due to the variable location of the articulation axis of the hanger.
[0013] Advantageously, said at least one top flange portion may comprise a plurality of longitudinally elongated fixing apertures arranged in parallel or angled relative to one another.
By providing the articulation axis, said top flange portion is adapted to bend about said articulation axis in a region defined by the length of said at least one longitudinally elongated fixing aperture. In this way, one joist hanger accommodates either face-fixing or top-fixing, wherein the selectively moveable top flange ensures a snug fit with the top surface of the support structure, even in the event that the top surface of the support structure is not perpendicular to its front surface. In particular, at the time of fixing the joist hanger to the support structure, the top flange is aligned exactly with the top surface of the support structure.
[0014] In addition, the joist hanger of the present invention provides the advantage that the top surface of the joist can be accurately aligned with the top surface of the support structure. In particular, the at least one longitudinally elongated fixing aperture provides a limited region within which the top flange may bend at the selected articulation axis about the edge of the support structure therefore providing a joist hanger depth that exactly matches the depth required to accurately align the top surfaces of the joist and support structure (which may be another joist or beam, for example). Furthermore, the at least one longitudinally elongated fixing aperture ensures that fixings, such as nails, can be placed through the top flange portion as well as through the back flange portion irrespective of the final joist hanger depth. Also, providing a plurality of longitudinally elongated apertures allows for a variety of fixing positions on the I-joist and support structure. For example, three longitudinally elongated fixing apertures may be arranged in parallel or angled relative to one another within the at least one top flange portion therefore providing optimized location for the fixings.
[0015] Therefore, the joist hanger of the present invention provides improved adaptability to variations in shape and size of the support structure and depth of the connected joists. Also, the multi-functional joist hanger (adjustable, top-fixing, face-fixing) provides the advantage of minimizing the cost for initial acquisition, because one joist hanger may be used for various applications and for a range of joist depths.
[0016] Preferably, said top flange portion may be coplanar with respect to said at least one back flange portion when in said face-fixing position.
[0017] Preferably, said top flange portion may adjoin said at least one back flange portion in a plane substantially perpendicular to the plane including said back flange portion when in said top-fixing position. It will be understood that in the top-fixing position, the top flange portion is bent relative to the back flange portion about the articulation axis of the hanger.
[0018] Said at least one back flange portion may adjoin said respective at least one of said two side portions in a plane non-coplanar to planes including said two side portions. Most specifically, said at least one back flange portion may adjoin said respective at least one of said two side portions in a plane substantially perpendicular to planes including said two side portions.
[0019] This provides the advantage that a simple blank of a predetermined shape can be used to form the joist hanger of the present invention.
[0020] The at least one back flange portion may include first and second back flange portions each adjoined to one of said two side portions, respectively. Preferably, said first and second back flange portion may extend laterally outward from respective side portions.
[0021] This provides the advantage of minimizing stress related rotation of the joist with respect to the support structure it is connected to.
[0022] Advantageously, said top flange portion may be detachable from said at least one back flange portion allowing the joist hanger to be limited to face fixing only. More specifically, the top flange portion may be detachable from said at least one back flange portion at the articulation axis. In this way, the top flange portion and the at least one back flange portion are separable from one another along the articulation axis of the hanger.
[0023] The joist hanger may further comprise at least one recess transversely aligned to and in a region defined by a length of said longitudinally elongated fixing aperture, and adapted to provide a predetermined crease line for said top flange portion. In these embodiments, the predetermined crease line forms the articulation axis of the hanger. Advantageously, the at least one recess may be located at or proximal to a lower apex of the at least one longitudinally elongated fixing aperture. Preferably, said at least one recess may be adapted to allow said at least one top flange portion to detach from respective said at least one back flange portion when moved back in a direction opposite to its top-fixing position. In such embodiments, the top flange portion is bent about the articulation axis relative to the back flange portion in a direction opposite to that forming the top-fixing position.
[0024] In certain embodiments, the joist hanger may further comprise a plurality of said recesses located at a plurality of predetermined positions within said region defined by the length of said at least one longitudinally elongated fixing aperture. More specifically, each of said plurality of recesses provides an articulation axis about which the top flange portion may be bent relative to the adjacent back flange portion.
[0025] This provides the advantage of facilitating the movement of the top flange portion into its top-fixing position about predetermined crease lines which crease lines form articulation axes. More than one predetermined recess may be used to provide a predetermined selection of crease line positions and improve the ease of use and variation of position.
[0026] The at least one top flange portion may comprise a first and second top flange portion adjoining said respective first and second back flange portion, each one of said first and second top flange portion may comprise said at least one longitudinally elongated fixing aperture and at least one articulation axis. Alternatively, the at least one top flange portion may comprise a first and second top flange portion adjoining said respective first and second back flange portion, each one of said first and second top flange portion may comprise said plurality of longitudinally elongated fixing apertures and at least one articulation axis.
[0027] Advantageously, said side portions, at least one back flange portion and/or said at least one top flange portion may be provided with a plurality of additional fixing apertures arranged so as to optimize load capacity.
[0028] At least part of said plurality of additional fixing apertures may be of circular shape. Alternatively, at least part of said plurality of additional fixing apertures may be of polygon shape. Preferably, at least part of said plurality of additional fixing apertures may be of triangular shape.
[0029] The circular shaped recesses, such as nail holes, are advantageously located at the top and bottom flanges or the openweb of the I-joist allowing fixing without backer blocks. The polygonal or triangular recesses, such as nail holes, may be optional and may provide an enhanced load and a fully face-fixed hanger.
[0030] The joist hanger may further comprise a base portion back plate upstanding from an edge of said base portion and coplanar with respect to said at least one back flange portion, and may be adapted to limit movement of a joist past said at least one back flange portion.
[0031] The base portion back plate may be an upstand or maybe provided by one or more lugs upstanding from the edge of the base portion and substantially perpendicular thereto.
[0032] Advantageously, the joist hanger may further comprise at least one edge flange adjoined along at least part of a longitudinal lateral edge of said at least one back flange portion. More specifically, the edge flange is located opposite the edge adjoining the side portion and may be folded forwardly of the back flange portion.
[0033] Advantageously, the joist hanger may further comprise at least one edge flange adjoined along at least part of a transverse edge of said at least one back flange portion.
[0035] The joist hanger may be substantially as herein described with reference to the accompanying drawings.
[0036] According to a second aspect of the present invention, there is provided a blank suitable for forming a joist hanger according to the first aspect of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] 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 (a) an isometric view of a known face-fix joist hanger connecting two I-joist, and (b) an isometric view of a known top-fix joist hanger connecting two I-joists,
Figure 2 shows an isometric view of a joist hanger in accordance with the present invention in its face-fixing position,
Figure 3 shows an isometric view of a joist hanger in accordance with the present invention in its top-fixing position,
Figure 4 shows a (a) top, (b) front and (c) side view of a joist hanger in accordance with the present invention in its face-fixing position,
Figure 5 shows (a) a partial view of a back flange portion and adjoined top-flange portion, wherein the top-flange portion comprises a transverse recess at or proximal to the lower apex of the longitudinally elongated fixing apertures, (b) a partial view of a back flange portion and adjoined top-flange portion, wherein the top-flange portion comprises a plurality of transverse recesses, a side view of the top flange portion moving from (c) its face-fixing position to (d) its top-fixing position about the predetermined crease line defined by a transverse recess, and
Figure 6 shows an isometric view of a joist hanger in accordance with the present invention in its permanent face-fixing position after top-flanges are snapped off.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0038] Referring now to Figures 2, 3 and 4, an example of a first embodiment of the joist hanger 100 is described. The joist hanger comprises a bracket 110, including a base portion 120 and two parallel side portions 130 upstanding perpendicular from opposing edges of the base portion 120. Two back flange portions 140 are adjoined to longitudinal edges of respective side portions 130, extending laterally in a plane perpendicular to the planes defined by each one of the two side portions 130. A top flange portion 150 is adjoined to each one of the two back flange portions 140 at a location distal to the base portion 120. Each one of the two top flange portion 150 includes three longitudinally elongated fixing apertures 160, which define a region about which the top flange portion 150 is preferably bent, or "wiped over" about an articulation axis extending transversely of the top flange portion 150 and back flange portion 140, when moving the top flange portion 150 between its face-fixing position and top-fixing position.
[0039] In this particular example, three longitudinally elongated fixing apertures 160 are positioned at acute angles with respect to each other. However, it is understood that any suitable number of longitudinally elongated fixing apertures 160 and respective parallel or angled position may be used. The longitudinally elongated fixing apertures 160 provide a region of least resistance when applying a bending force to the top flange portion 150. Therefore, the top flange portion 150 may be repeatedly moved about an articulation axis between its face-fixing position and top-fixing position without significantly compromising the structural integrity of the joist hanger 100.
[0040] Additional fixing apertures 180, 182 may be provided on the side portions 130, the back flange portions 140 and the top flange portions 150, where they are strategically placed to fix the joist hanger 100 to the side and top surfaces of the joist flanges or, in case backer blocks are used, within a region of the joist web. Preferably, the additional fixing apertures 180 for the joist flange are of circular shape, wherein the additional fixing apertures 182 for the joist web are of triangular shape. However, it is understood by the person skilled in the art that any suitable number, location and shape may be used for the additional fixing apertures 180, 182.
[0041] Furthermore, the base portion 120 may include a base portion back plate 122 upstanding from an edge of the base portion and coplanar with the back flange portions 140. The base portion back plate 122 may be replaced by one or more lugs foldable out of the plane of the base portion to be upstanding substantially perpendicular therefrom.
[0042] In use, the joist hanger 100 may be positioned and fixed at a side surface of another joist or support structure such that the top surfaces of the connecting joists are vertically aligned and the top flange portion 150 overlaps the edge of the side surface of the other joist or support structure. A force is then applied to the top flange portion 150 in order to bend ("wipe over") the top flange portion 150 at the edge 170 of the joists side surface (see Figure 3). Fixings, such as nails or screws or any other fixing elements, are placed through the additional fixing apertures 180, 182. In the particular example of using the joist hanger in its top-fixing position, fixings may only be placed into the top surface of the support structure through the longitudinally elongated fixing apertures 160 and/or the additional fixing apertures 180. The longitudinally elongated fixing apertures 160 ensure that the fixing for the top surface of the support structure can be optimally located irrespective of the depth of the front surface of the support structure, such as an I-joist.
[0043] The top-fixed joist hanger 100 may be reused for face-fixing as well as another top-fixing by simply removing the fixings (e.g. nails) and moving the top flange portion 150 back to its face-fixing position.
[0044] Referring now to Figure 5 and 6, the top flange portion 150 may be snapped off to ensure the joist hanger is only used for face-fixing. Snapping off the top flange portion 150 can be particularly useful when the joist hanger 100 has been reused and the top flange portion 150 has been moved frequently, and the structural integrity of the top flange portion is compromised.
[0045] In an alternative embodiment, the top flange portion 150 may be provided with an articulation axis in the form of a transverse recess 200 to facilitate the movement of the top flange portion and provide a predetermined crease line about which the top flange portion is bent with respect to the back flange portion 140. Also, the transverse recess 200 assists the user when either bending or snapping off the top flange portion 150, therefore improving the ease of use. Preferably, the transverse recess 200 is located at or proximal to a lower apex of the at least one longitudinally elongated fixing apertures 160.
[0046] Additionally, further transverse recesses 202, 204 may be provided at different locations within the region of the top flange defined by the length of the longitudinally elongated fixing apertures 160. This provides additional articulation axes in the form of predetermined crease lines facilitating the movement and/or detachment of the top flange portion 150 at specific locations.
[0047] During top-fixing use, the top flange portion 150 may be placed at the side surface of the support structure (e.g. joist) such that a predetermined transverse recess 200, 202, 204 is aligned with the edge of the support structure. The top flange portion 105 is then bent ("wiped over") at the predetermined transverse recess 200, 202, 204 and fixed to the top surface via fixings (e.g. nails). In the event the user wishes to limit the joist hanger to face fixing only, the top flange portion 150 is simply moved in a direction opposite its top-fixing position about a transverse recess 200, 202, 204 so that it snaps off at a predetermined location providing a clean cutting profile 210.
[0048] Additionally, another edge flange (not shown) may be provided along the longitudinal lateral edge and/or a transverse proximal edge of each one of the two back flange portions 140 in order to provide optimal stiffness to the joist hanger 100.
[0049] The joist hanger 100 of the present invention may be manufactured by cutting or pressing a suitable blank and subsequently bending the pre-cut /pre-pressed sides to form the joist hanger 100.
[0050] It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departing from the scope of the invention as defined by the appended claims.
1. A joist hanger comprising:
a support bracket, having a base portion and two substantially parallel side portions upstanding from opposing edges of said base portion;
at least one back flange portion adjoining at least one of said two side portions at a longitudinal edge of respective at least one of said two side portions and adapted to abut a face-fixing surface;
at least one top flange portion, adjoining said at least one back flange portion at an edge distal to said base portion and adapted to be moveable between a face-fixing position, wherein said top-flange portion is coplanar said at least one back flange portion, and a top-fixing position, wherein said top flange portion is non-coplanar to said at least one back flange portion, further comprising at least one longitudinally elongated fixing aperture and an articulation axis extending transversely of the hanger between the top flange portion and the back flange portion and being variable in location within the region defined by the length of said longitudinally elongated fixing aperture.
2. A joist hanger according to claim 1, wherein said at least one top flange portion
comprises a plurality of longitudinally elongated fixing apertures arranged in parallel
or angled relative to one another.
3. A joist hanger according to any one of the preceding claims, wherein said top flange
portion is coplanar with respect to said at least one back flange portion when in
said face-fixing position.
4. A joist hanger according to any one of the preceding claims, wherein said top flange
portion adjoins said at least one back flange portion in a plane substantially perpendicular
to the plane including said back flange portion when in said top-fixing position.
5. A joist hanger according to any one of the preceding claims, wherein said at least
one back flange portion adjoins said respective at least one of said two side portions
in a plane non-coplanar to planes including said two side portions.
6. A joist hanger according to claim 5, wherein said at least one back flange portion
adjoins said respective at least one of said two side portions in a plane substantially
perpendicular to planes including said two side portions.
7. A joist hanger according to any one of the preceding claims, wherein said at least
one back flange portion includes first and second back flange portion adjoined to
one of said two side portions, respectively.
8. A joist hanger according to claim 7, wherein said first and second back flange portions
extend laterally outward from respective side portions.
9. A joist hanger according to any one of the preceding claims, wherein said top flange
portion is detachable from said at least one back flange portion.
10. A joist hanger according to claim 9, wherein said top flange portion is detachable
from said at least one back flange portion at the articulation axis.
11. A joist hanger according to any one of the preceding claims, further comprising at
least one recess transversely aligned to and in a region defined by a length of said
at least one longitudinally elongated fixing aperture, and adapted to provide a predetermined
crease line for said top flange portion.
12. A joist hanger according to claim 11, wherein said at least one recess is located
at or proximal to a lower apex of the at least one longitudinally elongated fixing
aperture.
13. A joist hanger according to claims 11 or 12, wherein said at least one recess is adapted
to allow said at least one top flange portion to detach from respective said at least
one back flange portion when moved back in a direction opposite to its top-fixing
position.
14. A joist hanger according to claims 11 to 13, further comprising a plurality of said
recesses located at a plurality of predetermined positions within said region defined
by the length of said at least one longitudinally elongated fixing aperture.
15. A joist hanger according to any one of the preceding claims, wherein said at least
one top flange portion comprises a first and second top flange portion adjoining said
respective first and second back flange portion, each one of said first and second
top flange portion comprising said at least one longitudinally elongated fixing aperture
and at least one articulation axis.
16. A joist hanger according to any one of claims 1 to 14, wherein said at least one top
flange portion comprises a first and second top flange portion adjoining said respective
first and second back flange portion, each one of said first and second top flange
portion comprising said plurality of longitudinally elongated fixing apertures and
at least one articulation axis.
17. A joist hanger according to any one of the preceding claims, wherein said side portions,
at least one back flange portion and/or said at least one top flange portion are provided
with a plurality of additional fixing apertures arranged so as to optimize load capacity.
18. A joist hanger according to any one of the preceding claims, further comprising a
base portion back plate upstanding from an edge of said base portion and coplanar
with respect to said at least one back flange portion, and adapted to limit movement
of a joist past said at least one back flange portion.
19. A joist hanger according to any one of the preceding claims, further comprising at
least one edge flange adjoined along at least part of a longitudinal lateral edge
of said at least one back flange portion.
20. A joist hanger according to any one of the preceding claims, further comprising at
least one edge flange adjoined along at least part of a transverse edge of said at
least one back flange portion.
21. A joist hanger substantially as herein described with reference to the accompanying
drawings.
22. A blank suitable for forming a joist hanger according to any one of claims 1 to 21.