AU2015100504A4 - Post cap, and post assembly - Google Patents

Abstract

(FIG. 1) A support post assembly, to support at least a portion of a building structure against vertical and/or horizontal loads, has a support post with a lower end 5 mountable in a support medium e.g. soil; and an upper end provide with a post cap securable to the building structure. The post cap has a top plate with a substantially horizontal top face; and a substantially vertical socket substantially at the mid-point of the bottom face of the top plate. The socket is dimensioned to receive the upper end of the post with a close fit. Pairs of 10 vertically spaced holes, in opposed wall portions of the socket, receive screws to secure the socket to the upper end of the post; while the building structure is fixed to the top face of the top plate by fasteners, welding or other suitable fixing methods. -- --- - - ---- ----- --0 In,

Description

1 POST CAP, AND POST ASSEMBLY BACKGROUND OF THE INVENTION: 1. Field of the Invention: 5 This invention relates to a post cap, and to a post assembly incorporating the post cap. The invention particularly relates, but is not limited to, a post cap for a post arranged to support a base, roof- or floor-assembly, of a building structure or the like; and to a post provided with the post cap for that 10 purpose. The skilled addressee will appreciate that the term "building structure or the like" can include domestic dwellings, storage structures, fences, advertising displays, or the like. 2. Prior art: 15 NB: The following discussion is by way of background information only, and is not to be considered a statement of the common general knowledge (CGK) in the area of technology. When designing the support structures for the types of building structures hereinbefore described, factors which should be considered 20 include: a) the dead weight load of the building structure to be supported; b) the lateral load(s) likely to be encountered by the building structure e.g. due to winds; and c) up-lift forces e.g. due to wind pressure coefficients and/or "heave" 25 in reactive soils in which the support posts for the support structures are located. In some locations within Australia, the winds blowing up the sides of hills or cliffs can generate considerable up-lift forces; as can the winds generated by extreme weather events such as cyclones. 30 Typically, the base / floor structure is anchored to the upper ends of the support posts by fixings applied on site, where the primary design concern is supporting the dead weight load only.

2 Such fixings generally provide little, if any, cross-bracing against lateral loads; and none, if any, strength against up-lift forces. Indeed, it is not unknown for building structures to be released from their support structures due to the up-lift forces created by winds during severe weather events and 5 or the "heave" of underlying reactive soils after a rain / flood event. Even if only some of the connections between the building structures and their support structures fail, the integrity of the building structures is compromised and may be difficult / very expensive to repair. In addition, the compromised integrity after one weather event storm, 10 may result in catastrophic failure of a building structure in a subsequent weather event, before the failed connections have been identified and repaired. OBJECTS OF THE INVENTION: 15 It is an object of the present invention to provide a post cap which overcomes, or at least ameliorates, the problems with existing post caps. Other preferred objects of the present invention will become apparent from the following description. 20 SUMMARY OF THE INVENTION: In one aspect, the present invention resides in a post cap mountable at an upper end of a support post for a building structure, the post cap including: a top plate, the top plate having a top face to be connected to, and 25 support, at least a portion of the building structure, and an opposed bottom face; a socket extending from the bottom face, substantially perpendicular thereto; the socket having at least one wall dimensioned for close fit with 30 the upper end of the support post when received within the socket; and a plurality of holes in at least two opposed wall portions of the at 3 least one wall and operable to receive respective fasteners to secure the socket to the upper end of the support post to restrain the post cap to the support post against vertical and/or horizontal forces applied to the post cap by the building structure. 5 Preferably, the socket is located at substantially centrally, in plan view, of the bottom face of the top plate; and in use, the upper end of the support post engages the bottom face of the top plate adjacent the at least one wall portion. Preferably, the socket is square or rectangular in end view, and 10 the at least two opposed wall portions are defined by respective opposed side walls of the socket. Preferably, the plurality of holes in the opposed wall portions are provided in vertically spaced pairs. In a second aspect, the present invention resides in a support post 15 assembly for a building structure, including: a support post, having at least one post wall, with a lower end engageable in a support medium, and an upper end; a post cap mountable at the upper end of the support post, the post cap including: 20 a top plate, the top plate having a top face to be connected to, and support, at least a portion of the building structure, and an opposed bottom face; a socket extending from the bottom face, substantially perpendicular thereto; 25 the socket having at least one wall dimensioned for close fit with the upper end of the support post engaged with the socket; a plurality of holes in at least two opposed wall portions of the at least one wall and operable to receive respective fasteners; and respective fasteners extending through the holes into fixing 30 engagement with the at least one post wall, the fasteners securing the socket to the upper end of the support post to thereby restrain the post cap to the support post against vertical and/or horizontal forces 4 applied to the post cap by the building structure. Preferably, the upper end of the support post is received within the socket; but the upper end may be hollow and surround the socket. Preferably, the portion of the building structure is secured to the top 5 plate by fasteners e.g. bolts, studs or screws; by welding; by adhesives or other fixing materials; or other suitable fixing means. The fixing means should preferably be selected to ensure that the building structure is secured to the top plate against preset loads or forces in both the vertical directions (i.e. dead weight load of the building structure and up-lift loads) and 10 horizontal (or shear) loads (e.g. due to wind forces). Other preferred features of the present invention will become apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS: 15 To enable the invention to be fully understood, and to enable the skilled addressee to put the invention into practice, a number of preferred embodiments will now be described, with reference to the accompanying illustrations, in which: FIG. 1 is a schematic side elevational view of a portion of a building 20 structure secured to a support post, using a post cap of a first embodiment of the present invention; FIG. 2 is a side elevational view of the post cap; and FIG. 3 is a schematic isometric view of the socket of the post cap (where the top plate has been omitted for clarity). 25 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS: Referring to FIG. 1, a building structure 100 is supported on a plurality of support posts 10 located at pre-designed spaced locations e.g. determined by the architect or engineer to be able to support the dead weight 30 of the building structure 100; oppose lateral and/or up-lift wind forces on the building structure 100; and/or any up-lift forces e.g. due to "heave" of the soils S in which the lower ends 11 of the posts 10 are anchored e.g. in 5 concrete C. In this embodiment, the posts 10 are of SHS-section, with front & rear walls 12 and side walls 13. The posts 10 are manufactured of suitable strength steel or aluminium, and may be treated with anti-corrosion 5 treatment(s) for long-life. The building structure 100 has a base frame 101 formed of suitable longitudinal and lateral beams 102 e.g. also of SHS- or RHS- section; or other suitable sections e.g. C-section or Z-section. The post cap 20 of the present invention enables the longitudinal 10 and/or lateral beams 102 to be secured connected to the upper ends 14 of the respective posts 10. The post cap 20 has a top plate 30 e.g. manufactured from suitable corrosion-protected steel, which is square in top plan view, with substantially horizontal opposed top and bottom faces 31, 32. The thickness of the top 15 plate 30 will be selected to achieve the desired load / force requirements. Holes 33 may be drilled through the top plate 30 before installation, or as required on-site, to enable the beams 102 to be fixed thereto e.g. with bolts-and-nuts 60, as illustrated in FIG. 1 The post cap 20 has a socket 40, of SHS-section, located 20 substantially centrally (i.e. at the mid-point) of the top plate 30; and the socket extends substantially vertically from the bottom face 32 of the top plate 30. The socket 40 is welded (e.g. by MIG- or TIG-welding) to the bottom face 32 of the top plate 30 As illustrated in FIG. 1, the socket 40 is dimensioned to receive the 25 upper end 11 of the respective post 10. Preferably, the internal dimensions of the opposed front-and-rear walls 42 and opposed side walls 43 of the socket 40 are just greater than the external dimensions of the complementary walls 12, 13 of the post 10, so that the upper end 14 of the post 10 is a close (or "interference") (telescopic) fit within the socket 40. 30 As better illustrated in FIG. 3, holes 45 are provided in the opposed front- and rear walls 42. Dependent on the intended application, the holes 45 are preferably provided in horizontally-aligned pairs, where the socket 40 of 6 the present embodiment is shown as having two vertically-spaced pairs of holes 45. Three or more pairs of holes 45 may be provided. In a modified embodiment, similar pairs of holes may be provided in the side walls 43 of the socket 40, but these would be vertically-offset from 5 the holes 45 in the walls 42. When the post cap 20 has been installed on the upper end 14 of the post 10 (with the upper end 14 engaging the bottom face 32 of the top plate 30 within the socket 40), respective screws 50 are driven through the holes 45, into the opposed walls 12 of the post 10, to secure the post cap 20 to the 10 post 10. The skilled addressee will appreciate that holes may be drilled through the walls 12 of the post, 10 in alignment with the holes 45 in the post cap 20, and that bolts-and-nuts may be substituted for the screws 50. The beam(s) 102 of the building structure 100 may then be located on 15 the top plate 30 and secured thereto e.g. by the bolts-and-nuts 60; screws; or other suitable fixing methods. In alternative embodiments, not illustrated, the posts and sockets may be of complementary RHS-section; and/ or the top plate may be rectangular, hexagonal, octagonal, circular or other suitable shape in plan view. 20 While the posts and sockets may be circular in cross-section, this would be for an atypical application, as the screws would be required to also resist any horizontal twisting forces tending to rotate the building structure relative to the posts. In a still further alternative embodiment for another atypical 25 application, the socket may be received within the upper end of the post; and the screws are driven through the post into the socket to secure the post cap in position. In this embodiment, the holes in the socket are omitted, or the holes are arranged to be not adjacent the wall portions of the post though which the screws are driven. 30 The holes in the top plate may be provided in any suitable pattern or arrangement; or, as hereinbefore described, may be omitted and them drilled on-site, to suit the particular intended application.

7 NB: In certain applications, e.g. where the soil S is particularly reactive, the lower ends of the posts may be connected to the upper ends of the respective shafts of screw piers or screw piles (not shown), driven into underlying soil strata, to provide resistance to any up-lift forces due to 5 "heave" in the soil S. Alternatively, the upper ends of the screw pier- or screw pile- shafts may constitute the support posts. The skilled addressee will appreciate that the embodiments described and illustrated provide a simple, economic, highly effective method for securing the building structure 100 to the respective posts. 10 Various other changes and modifications may be made to the embodiments described and illustrated without departing from the present invention.

Claims (5)

1. A post cap mountable at an upper end of a support post for a building structure, the post cap including: 5 a top plate, the top plate having a top face to be connected to, and support, at least a portion of the building structure, and an opposed bottom face; a socket extending from the bottom face, substantially perpendicular thereto; 10 the socket having at least one wall dimensioned for close fit with the upper end of the support post when received within the socket; and a plurality of holes in at least two opposed wall portions of the at least one wall and operable to receive respective fasteners to secure the socket to the upper end of the support post to restrain the post cap to the support post 15 against vertical and/or horizontal forces applied to the post cap by the building structure.

2. The post cap of claim 1, wherein: the socket is located at substantially centrally, in plan view, of the 20 bottom face of the top plate; and in use, the upper end of the support post engages the bottom face of the top plate adjacent the at least one wall portion.

3. The post cap of claim or claim 2, wherein: 25 the socket is square or rectangular in end view, and the at least two opposed wall portions are defined by respective opposed side walls of the socket.

4. The post cap of any one of claims 1 to 3, wherein: 30 the plurality of holes in the opposed wall portions are provided in vertically spaced pairs. 9

5. A support post assembly, for a building structure, including: a support post, having at least one post wall, with a lower end engageable in a support medium, and an upper end; a post cap mountable at the upper end of the support post, the post 5 cap including: a top plate, the top plate having a top face to be connected to, and support, at least a portion of the building structure, and an opposed bottom face; a socket extending from the bottom face, substantially perpendicular 10 thereto; the socket having at least one wall dimensioned for close fit with the upper end of the support post engaged with the socket; a plurality of holes in at least two opposed wall portions of the at least one wall and operable to receive respective fasteners; and 15 respective fasteners extending through the holes into fixing engagement with the at least one post wall, the fasteners securing the socket to the upper end of the support post to thereby restrain the post cap to the support post against vertical and/or horizontal forces applied to the post cap by the building structure. 20