Patent Description:
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.

<CIT> discloses an anchor bolt and a threaded sleeve for fixing a framing plate to a support structure, wherein the anchor bolt comprising a threaded shaft bearing threads, while the threaded sleeve member comprising internal threads compatible with the threads of the anchor bolts.

<CIT> provides a fastener assembly for attaching a composite panel section or the like to a frame section. The fastener assembly comprises a bolt member having a tamperproof enlarged head portion, and a nut member engageable with the bolt member.

The fastening device depicted in <CIT> comprises two fastening members, wherein one of them is a male fastening member, while the other is a female fastening member provided with a threaded opening of a size to receive and have threaded engagement with a stud of the male fastening member.

<CIT> discloses a fixed structure for a handrail, wherein the fixed structure comprising an anchor bolt embedded in a floor and protruding upwards out of the floor, a washer and a nut screwed onto the anchor bolt.

According to a first aspect of the invention there is provided a threaded fastener pair, including:.

Preferably, at a base of the female threaded portion is an unthreaded cylindrical bore.

Preferably, the length of the first threaded fastener is at least <NUM>.

According to preferred embodiments, a shank of the first threaded fastener is at least <NUM> long and has a diameter of at least <NUM>. 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:.

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:.

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.

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:.

A threaded fastener pair <NUM> according to a preferred embodiment of the invention is illustrated in <FIG>.

The threaded fastener pair <NUM> includes a first fastener <NUM> with a male threaded portion <NUM>, and a second fastener <NUM> with a female threaded portion <NUM>. The female threaded portion <NUM> is configured to receive the male threaded portion <NUM>.

In the illustrated embodiment, the fasteners are of equal length and length A2 equals length B2. Also, length A1 equals length B1, with B1 being the length of which fastener <NUM> extends past the midpoint or centreline x between the heads of each fastener.

The first fastener <NUM> is formed with a shank <NUM> having an outer diameter approximately equal to an outer diameter of the second fastener <NUM>. In a preferred form, the shank <NUM> of the first threaded fastener <NUM> is at least <NUM> long and has a diameter of at least <NUM>.

In preferred embodiments, the second threaded fastener <NUM> has a length equal to or greater than that of the first threaded fastener <NUM> and the length of the first threaded fastener <NUM> is at least <NUM>. In preferred forms, the first threaded fastener <NUM> is available in lengths of <NUM>, <NUM>, <NUM>, <NUM> and <NUM>, though it will be appreciated that longer lengths may also be possible.

By providing a first threaded fastener <NUM> with a shank <NUM> having an outer diameter that is approximately equal to an outer diameter of the second fastener <NUM>, and the fasteners <NUM>, <NUM> 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 <NUM> 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 <NUM>.

Each fastener <NUM>, <NUM> 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.

<FIG>, <FIG> illustrate the threaded fastener pair <NUM> in use with a post support system <NUM> of a first embodiment, which includes a post support <NUM> having an upwardly extending blade <NUM>, and a generally vertical post <NUM>. In this example, four threaded fastener pairs are used and extend through apertures <NUM> formed in the blade <NUM>.

The post support <NUM> is provided with apertures <NUM> to allow securement of the post <NUM> to a ground surface.

Each threaded fastener pair is configured for extending through a transverse hole formed in an end of the post <NUM> and through an aperture formed in the support <NUM>. In use, a hole is formed in the post <NUM>, the hole being of the same size as the corresponding aperture in the support <NUM>.

In use, the size of the first and second fasteners is chosen to provide a sufficient overlap, which is preferably <NUM>, at the centre of the connection, i.e. the midpoint between the heads of the first and second fasteners <NUM>, <NUM>, so that not only the blade <NUM> is supported on the fastener pair <NUM>, but the post immediately beside the blade <NUM> is well supported on both sides of the blade <NUM> and also by the shank <NUM> near the head of the first fastener <NUM>. This provides a secure connection between the post <NUM> and the post support <NUM>, 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 <NUM>, <NUM> 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 <NUM>, 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 <NUM>, 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 <NUM>, one with a length of <NUM>, one with a length of <NUM>, one with a length of <NUM> and one with a length of <NUM>.

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 <NUM> for use with the threaded fastener pair and post support system is illustrated in <FIG>. In addition to having a central upstanding blade <NUM> for engagement with a post (not shown), two apertures <NUM> are formed in the blade <NUM> through which a threaded fastener pair can extend to secure the post to the support <NUM>. Again, it will be appreciated that the number of threaded fastener pairs used can be varied.

The post support <NUM> includes a base <NUM> to be received against a surface to which the post is to be secured, which is typically a concrete surface, and an aperture <NUM> through which a fastener can extend to secure the post support <NUM> to the surface. A stand <NUM> is provided to space the end of the post from the ground surface and may be any desired length. A plate <NUM> is secured to the stand <NUM> and provided for abutment with an end of the post.

<FIG> illustrates another post support <NUM> for use with the threaded fastener pair and a further embodiment of the post support system. In this embodiment, stand <NUM> and plate <NUM> are omitted, with blade portion <NUM> being provided with a mounting flange <NUM> for securement to the surface. Post support <NUM> may be formed of a single piece of material, or from two or more pieces of material. As can be seen in <FIG>, a concealing cap <NUM> is provided to cover the flange <NUM> and end of the blade portion <NUM> to provide a clean finish. In use, after flange <NUM> is secured to a surface, cap <NUM> is passed over the bladed portion <NUM> before the post is secured to the post support <NUM>.

In each of the post supports <NUM>, <NUM>, <NUM> the blade portion <NUM>, <NUM>, <NUM> is centrally disposed on the support <NUM>, <NUM>, <NUM> 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 <NUM>, <NUM>, <NUM> may be provided, as will be described further below.

In use, to form a connection between the post and the post support <NUM>, <NUM>, <NUM>, a slit is first cut in an end of a post to be secured. The slit is formed to correspond to a blade portion <NUM>, <NUM>, <NUM> of the post support. Transverse holes are formed in the same end of the post <NUM> and positioned to align with apertures <NUM>, <NUM> formed in the support <NUM>, <NUM>, <NUM>, which is secured to a ground surface, which may be a concrete surface for example, using commonly available concrete fasteners.

<FIG>, <FIG> illustrate a further post support system <NUM>. This system <NUM> uses a post support <NUM> having a "U" or saddle shape, having two upstanding blade portions <NUM>, which are configured to be received on opposite external sides of the post <NUM>.

Two threaded fastener pairs <NUM> are used and again it will be appreciated that the number of apertures provided can be varied.

As per post support <NUM>, post support <NUM> has a base <NUM> to be received against a surface to which the post is to be secured, which is typically a concrete surface, and two apertures <NUM> through which a fastener can extend to secure the post support <NUM> to the surface. A stand <NUM> is provided to space the end of the post from the ground surface and may be any desired length. A support portion <NUM> is secured to the stand <NUM> and provided for abutment with an end of the post. In the illustrated embodiment, the support portion <NUM> and the two blade portions <NUM> are integrally formed.

As can be seen in <FIG>, the post support <NUM> is supported on both sides by close engagement with the male/female threaded fasteners <NUM>, <NUM>. In this regard, on one side the post support <NUM> sits on the female fastener <NUM> and on the other side the post support <NUM> sits on the shank of the male fastener <NUM>. Using a threaded fastener pair of a male/female threaded fasteners <NUM>, <NUM> 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>, each fastener is solid where it passes through the blade portion <NUM> 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.

<FIG>, <FIG> illustrate the use of the fastener pair <NUM> in a timber to timber connection <NUM>.

The connection <NUM> is part of a roof truss and formed between bottom chord <NUM> and truss webs <NUM>. In this example, two threaded fastener pairs are used to secure the vertical web to the bottom chord <NUM> and a single threaded fastener pair for securing the other webs.

As can be seen in <FIG>, the length of the first and second fasteners is chosen to provide a sufficient overlap, which is preferably <NUM>, at the centre of the connection, i.e. the midpoint between the heads of the first and second fasteners <NUM>, <NUM>, so that both the bottom chord <NUM> and the web <NUM> are located/aligned with each other and well supported on the bore of the apertures formed therein. In this regard, the female threaded fastener <NUM> extends through the bottom chord <NUM> and partially into the web <NUM>, which is supported on one side by the female threaded fastener and at the other side, the shank <NUM> of the first threaded fastener <NUM>.

This provides a secure connection between the post <NUM> and the post support <NUM>, 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 <NUM>, <NUM> 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.

Claim 1:
A threaded fastener pair (<NUM>), including:
a first threaded fastener (<NUM>) with a male threaded portion (<NUM>); and
a second threaded fastener (<NUM>) with a female threaded portion (<NUM>), the female portion (<NUM>) being configured to receive the male threaded portion (<NUM>),
characterised in that the first threaded fastener (<NUM>) is formed with a shank (<NUM>) having an outer diameter approximately equal to an outer diameter of the second threaded portion, and the second threaded fastener (<NUM>) has a length equal to or greater than that of the first threaded fastener (<NUM>) so that the outer diameter of the second threaded portion supports a load at a midpoint between outer ends of the threaded fasteners (<NUM>, <NUM>).