Patent Publication Number: US-2022228612-A1

Title: Threaded fastener pair, post anchor system and method of securing a post to a post anchor

Description:
FIELD OF THE INVENTION 
     The present invention relates to a threaded fastener pair for joining materials together, in particular for applications where both ends of the fastener are visible, and for use with a post anchor system. The present invention also relates to a post anchor system and a method of securing a post to a post anchor. 
     BACKGROUND 
     Conventional bolts are often used for joining material such as timber pieces together as they are easy to use, reliable and cost effective. However, in applications where both sides or ends of the fastener are visible, an exposed end of thread protruding from a nut at one end of the fastener is visually unappealing and can potentially cause injury through unintentional contact. To minimise the length of thread protruding from a nut, variously sized fasteners are required to be provided. 
     There are many applications for such connections, including for example, timber to timber connections, particularly for roof truss connections, joist connections, staircases, handrails, exposed beams, architectural timber connections, exposed rafter connections, and LVL beam connector bolts. 
     A further application of such a connection is with a post support or anchor for a vertical post. Post supports are a convenient way of supporting and securing a vertical post to a ground surface such as concrete. However, some previous post anchors have been visually unappealing and also typically require traditional bolts extending transversely through an end of the post for securing the post to the anchor and this results, on one side of the anchor, in a nut and exposed thread being visible and exposed for unintentional contact. Such an arrangement is visually undesirable and unintentional contact with an exposed end of a threaded bolt has the potential to cause injury. 
     Furthermore, it is desirable to ensure that the connection between the post and the anchor is secure as possible. 
     There is a need to address the above, and/or at least provide a useful alternative. 
     SUMMARY 
     According to a first aspect of the invention there is provided a threaded fastener pair, including: 
     a first threaded fastener with a male threaded portion; and 
     a second threaded fastener with a female threaded portion, the female portion being configured to receive the male threaded portion, 
     wherein the first threaded fastener is formed with a shank having an outer diameter approximately equal to an outer diameter of the second threaded fastener, the second threaded fastener has a length equal to or greater than that of the first threaded fastener and the length of the first threaded fastener is at least 45 mm. 
     Preferably, at a base of the female threaded portion is an unthreaded bore. 
     According to another aspect of the invention there is provided a threaded fastener pair, including: 
     a first threaded fastener with a male threaded portion; and 
     a second threaded fastener with a female threaded portion, the female portion being configured to receive the male threaded portion, 
     wherein the first threaded fastener is formed with a shank having an outer diameter approximately equal to an outer diameter of the second threaded portion, the second threaded fastener has a length equal to or greater than that of the first threaded fastener and at a base of the female threaded portion is an unthreaded bore. 
     Preferably, the length of the first threaded fastener is at least 45 mm. 
     According to preferred embodiments, a shank of the first threaded fastener is at least 5 mm long and has a diameter of at least 10 mm. Preferably, each fastener is formed with a domed head having a socket drive. 
     According to another aspect of the invention there is provided a post anchor system, comprising: 
     a post support securable to a ground surface and having at least one blade portion extending upwardly therefrom for engagement with a generally vertical post, the blade portion having at least one aperture through which a fastener can extend to secure the post to the support; and 
     at least one threaded fastener pair including:
         a first threaded fastener with a male threaded portion; and   a second threaded fastener with a female threaded portion, the female portion being configured to receive the male threaded portion,   wherein the first threaded fastener is formed with a shank having an outer diameter approximately equal to an outer diameter of the second threaded fastener.       

     According to preferred embodiments, the second threaded fastener has a length equal to or greater than that of the first threaded fastener. Preferably, the length of the first threaded fastener is at least 45 mm. 
     Preferably, the blade portion is centrally disposed on the support which is configured to be received in a slit formed in an end of the post. Preferably, the slit extends along a central longitudinal axis of the post. 
     The system may have two, three or four threaded fastener pairs. The post support may have a concealing cap to cover a bolt down portion at a lower portion of the post support. 
     According to another aspect of the invention there is provided a threaded fastener pair for use with a post support system of the above described type. 
     According to another aspect of the invention there is provided a method of securing a post to a post support, including the steps of: 
     providing a post; 
     providing a post support securable to a ground surface and having at least one blade portion extending upwardly therefrom for engagement with the post, the blade portion having at least one aperture through which a fastener can extend to secure the post to the support; 
     providing at least one threaded fastener pair including:
         a first threaded fastener with a male threaded portion; and   a second threaded fastener with a female threaded portion, the female portion being configured to receive the male threaded portion,   wherein the first threaded fastener is formed with a shank having an outer diameter approximately equal to an outer diameter of the second threaded fastener,       

     forming at least one hole transversely through an end of the post through which the fastener pair can be received; 
     bringing the post into engagement with the post support; and 
     passing each fastener of the fastener pair through an opposite side of the post and through the blade portion and bringing them into engagement to secure the post to the support. 
     Preferably, the method further includes the step of cutting a slot in an end of the post for receipt of the blade portion, the slot passing through a central longitudinal axis of the post. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the invention may be more easily understood, an embodiment will now be described, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  is a side view of a fastener pair according to one embodiment of the invention; 
         FIGS. 2 a  and 2 b    are perspective views of male fastener of the pair; 
         FIGS. 3 a  and 3 b    are respective side and sectional side views of the fastener of  FIGS. 2 a    and  2   b;    
         FIGS. 4 a  and 4 b    are perspective views of a female fastener of the pair; and 
         FIGS. 5 a  and 5 b    are respective side and sectional side views of the fastener of  FIGS. 4 a    and  4   b.    
         FIG. 6  is a perspective view of a post anchor system according to a preferred embodiment of the invention; 
         FIG. 7 a    is a side view of the system of  FIG. 6 ; 
         FIG. 7 b    is an enlarged sectional view of Detail A of  FIG. 7   a;    
         FIG. 8  is an alternative post anchor for use with the system; 
         FIG. 9 a    is another post anchor for use with the system; 
         FIG. 9 b    is a cap for use with the post anchor of  FIG. 9   a;    
         FIG. 10  is a perspective view of a post anchor system according to another embodiment; 
         FIG. 11 a    is a side view of the system of  FIG. 10 ; 
         FIG. 11 b    is an enlarged sectional view of Detail A of  FIG. 11   a;    
         FIG. 12  is a perspective view of a fastener pair of  FIG. 1  used in a timber to timber connection; 
         FIG. 13 a    is a side view of the connection of  FIG. 12  and 
         FIG. 13 b    is an enlarged sectional view of Detail A of  FIG. 13   a.    
     
    
    
     DETAILED DESCRIPTION 
     A threaded fastener pair  10  according to a preferred embodiment of the invention is illustrated in  FIG. 1 . 
     The threaded fastener pair  10  includes a first fastener  12  with a male threaded portion  13 , and a second fastener  14  with a female threaded portion  15 . The female threaded portion  15  is configured to receive the male threaded portion  13 . 
     In the illustrated embodiment, the fasteners are of equal length and length A 2  equals length B 2 . Also, length A 1  equals length B 1 , with B 1  being the length of which fastener  14  extends past the midpoint or centreline x between the heads of each fastener. 
     The first fastener  12  is formed with a shank  16  having an outer diameter approximately equal to an outer diameter of the second fastener  14 . In a preferred form, the shank  16  of the first threaded fastener  12  is at least 5 mm long and has a diameter of at least 10 mm. 
     In preferred embodiments, the second threaded fastener  14  has a length equal to or greater than that of the first threaded fastener  12  and the length of the first threaded fastener  12  is at least 45 mm. In preferred forms, the first threaded fastener  12  is available in lengths of 45 mm, 50 mm, 70 mm, 110 mm and 190 mm, though it will be appreciated that longer lengths may also be possible. 
     By providing a first threaded fastener  12  with a shank  16  having an outer diameter that is approximately equal to an outer diameter of the second fastener  14 , and the fasteners  12 ,  14  being of equal length, when joining two materials together an inner bore of the materials is well supported, as will be further described below. Such a connection is particularly useful for a post anchor connection where strong engagement between the post, the anchor and the fastener is required. 
     Those skilled in the art will appreciate that the female threaded portion  15  is quite long compared to prior art fasteners of this type. To allow such a deep thread to be formed, at a base of the female threaded portion is an unthreaded bore  18 . 
     Each fastener  12 ,  14  is formed with a domed head having a socket drive. The domes head may be a truss head or button head for example. Also, any suitable socket type may be used, such as a star drive or hex socket for example. 
       FIGS. 6, 7   a  and  7   b  illustrate the threaded fastener pair  10  in use with a post support system  20  of a first embodiment, which includes a post support  22  having an upwardly extending blade  24 , and a generally vertical post  26 . In this example, four threaded fastener pairs are used and extend through apertures  17  formed in the blade  24 . 
     The post support  22  is provided with apertures  23  to allow securement of the post  22  to a ground surface. 
     Each threaded fastener pair is configured for extending through a transverse hole formed in an end of the post  26  and through an aperture formed in the support  22 . In use, a hole is formed in the post  26 , the hole being of the same size as the corresponding aperture in the support  22 . 
     In use, the size of the first and second fasteners is chosen to provide a sufficient overlap, which is preferably 30 mm, at the centre of the connection, i.e. the midpoint between the heads of the first and second fasteners  12 ,  14 , so that not only the blade  24  is supported on the fastener pair  10 , but the post immediately beside the blade  24  is well supported on both sides of the blade  24  and also by the shank  16  near the head of the first fastener  12 . This provides a secure connection between the post  26  and the post support  22 , with equivalent strength to a conventional bolted connection, but without suffering the above mentioned drawbacks of using conventional threaded fasteners. 
     Using a threaded fastener pair of a male/female threaded fasteners  12 ,  14  allows any excess thread to be accommodated within the connection of the fasteners so that the only parts visible from outside of the system are two bolt heads, which are preferably domed heads. This provides a nice clean finish, and removes any exposed thread/nuts that can look untidy and may unintentionally cause injury. Such an arrangement also means that a limited number of sizes can be provided for multiple applications. 
     Although illustrated as having dome heads with a socket for receipt of a star driver bit, which is the preferred embodiment, it will be appreciated that the fastener heads may take other forms such as a standard hexagon head, rounded screw head, button or countersunk hexagon socket for example. 
     With threaded fastener pair  10 , structural integrity of the fastener joint is improved as the centre of the bolt is always between the heads of the fasteners to provide loading through a central plane of the post  12 , and avoiding offset loading creating torque on the joint. 
     Also, as excess thread can easily be accommodated within the connection, only a limited number of sized bolts are required to be provided and can be used for many different sized posts, thereby reducing the costs associated with making and stocking many different sized fastener pairs. It is envisaged that five sizes of male/female threaded portion will be sufficient, one with a length of 45 mm, one with a length of 50 mm, one with a length of 70 mm, one with a length of 110 mm and one with a length of 190 mm. 
     In the illustrated embodiments, four threaded fastener pairs are provided, though it will be appreciated that to suit the different requirements of a specific application, embodiments having less than or more than four fastener pairs may also be provided. 
     Another example of post support  122  for use with the threaded fastener pair and post support system is illustrated in  FIG. 8 . In addition to having a central upstanding blade  124  for engagement with a post (not shown), two apertures  117  are formed in the blade  124  through which a threaded fastener pair can extend to secure the post to the support  122 . Again, it will be appreciated that the number of threaded fastener pairs used can be varied. 
     The post support  122  includes a base  128  to be received against a surface to which the post is to be secured, which is typically a concrete surface, and an aperture  130  through which a fastener can extend to secure the post support  122  to the surface. A stand  132  is provided to space the end of the post from the ground surface and may be any desired length. A plate  134  is secured to the stand  132  and provided for abutment with an end of the post. 
       FIG. 9 a    illustrates another post support  222  for use with the threaded fastener pair and a further embodiment of the post support system. In this embodiment, stand  132  and plate  134  are omitted, with blade portion  224  being provided with a mounting flange  236  for securement to the surface. Post support  222  may be formed of a single piece of material, or from two or more pieces of material. As can be seen in  FIG. 9 b   , a concealing cap  238  is provided to cover the flange  236  and end of the blade portion  224  to provide a clean finish. In use, after flange  236  is secured to a surface, cap  238  is passed over the bladed portion  224  before the post is secured to the post support  222 . 
     In each of the post supports  22 ,  122 ,  222  the blade portion  24 ,  124 ,  224  is centrally disposed on the support  22 ,  122 ,  222  so as to be generally in alignment with a longitudinal axis of the post. In other embodiments, it may be offset toward a side of the post, or configured so as to abut an external side surface of the post. Also, more than one blade portion  24 ,  124 ,  224  may be provided, as will be described further below. 
     In use, to form a connection between the post and the post support  22 ,  122 ,  222 , a slit is first cut in an end of a post to be secured. The slit is formed to correspond to a blade portion  24 ,  124 ,  224  of the post support. Transverse holes are formed in the same end of the post  12  and positioned to align with apertures  17 ,  117  formed in the support  22 ,  122 ,  222 , which is secured to a ground surface, which may be a concrete surface for example, using commonly available concrete fasteners. 
       FIGS. 10, 11   a  and  11   b  illustrate a further post support system  320 . This system  329  uses a post support  322  having a “U” or saddle shape, having two upstanding blade portions  124 , which are configured to be received on opposite external sides of the post  326 . 
     Two threaded fastener pairs  10  are used and again it will be appreciated that the number of apertures provided can be varied. 
     As per post support  122 , post support  322  has a base  328  to be received against a surface to which the post is to be secured, which is typically a concrete surface, and two apertures  330  through which a fastener can extend to secure the post support  322  to the surface. A stand  332  is provided to space the end of the post from the ground surface and may be any desired length. A support portion  334  is secured to the stand  332  and provided for abutment with an end of the post. In the illustrated embodiment, the support portion  334  and the two blade portions  324  are integrally formed. 
     As can be seen in  FIGS. 11 a  and 11 b   , the post support  322  is supported on both sides by close engagement with the male/female threaded fasteners  12 ,  14 . In this regard, on one side the post support  322  sits on the female fastener  14  and on the other side the post support  322  sits on the shank of the male fastener  12 . Using a threaded fastener pair of a male/female threaded fasteners  12 ,  14  allows any excess thread to be accommodated within the connection of the fasteners so that the only parts visible from outside of the system are two bolt heads, which are preferably domed heads. This provides a nice clean finish, and removes any exposed thread/nuts that can look untidy and may unintentionally cause injury. 
     Also, as can be seen in  FIG. 11 b   , each fastener is solid where it passes through the blade portion  324  and into the post. As such the post sits on a solid section within the fasteners so as to mimic the load support of a conventional bolt. If the female fastener was hollow in this area, it could be vulnerable to shear under high loading. 
     It will be appreciated that the described post anchors can come in many different sizes and configurations for use in different applications and with differently sized posts. For example, different post anchors may have differently sized plates and stands, number and sizes of apertures and lengths of blade. 
       FIGS. 12, 13   a  and  13   b  illustrate the use of the fastener pair  10  in a timber to timber connection  450 . 
     The connection  450  is part of a roof truss and formed between bottom chord  452  and truss webs  454 . In this example, two threaded fastener pairs are used to secure the vertical web to the bottom chord  452  and a single threaded fastener pair for securing the other webs. 
     As can be seen in  FIGS. 13 a  and 13 b   , the length of the first and second fasteners is chosen to provide a sufficient overlap, which is preferably 30 mm, at the centre of the connection, i.e. the midpoint between the heads of the first and second fasteners  12 ,  14 , so that both the bottom chord  452  and the web  454  are located/aligned with each other and well supported on the bore of the apertures formed therein. In this regard, the female threaded fastener  14  extends through the bottom chord  452  and partially into the web  454 , which is supported on one side by the female threaded fastener and at the other side, the shank  16  of the first threaded fastener  12 . 
     This provides a secure connection between the post  26  and the post support  22 , without suffering the above mentioned drawbacks of using conventional threaded fasteners. 
     Again, it will be seen that using a threaded fastener pair of a male/female threaded fasteners  12 ,  14  allows any excess thread to be accommodated within the connection of the fasteners so that the only parts visible from outside of the system are two bolt heads, which are preferably domed heads. This provides a nice clean finish, and removes any exposed thread/nuts that can look untidy and may unintentionally cause injury. 
     During assembly, for each aperture formed in the material to be connected, which may be a post with a post anchor or a bottom chord and webs of a truss, a threaded fastener pair is provided. Once the materials are brought into engagement with each other, the fasteners of the pair are inserted into the apertures from opposite sides of the joint. Once the fasteners are in engagement with each other, they can be tightened so that a head of each fastener clamps against an external surface of the materials to secure them together. The result is a secure, well supported and visually clean joint, without an exposed end of a threaded fastener being visible. 
     Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. 
     The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.