Concealed structural post fastening device and method

Abstract

A post fastening device for mounting a post to a construction surface, the device comprising a base having a planar top surface and a threaded rod extending from the top surface, a tubular member for insertion into a longitudinal axial bore on the bottom end of the post, the tubular member having an upper end and a lower end with internal threads complementary to the threads of the rod, and a dowel rod for insertion into a transverse bore extending through a portion of the post and the tubular member when the tubular member is in the longitudinal bore, the dowel rod being sized to pass through the tubular member and a portion of the post on both sides of the tubular member.

Claims

1. A method of mounting a post having a bottom end to a construction surface, the method comprising: mounting onto the construction surface a base having a planar top surface and a threaded rod extending from the top surface; machining a longitudinal bore into the bottom end of the post along a central longitudinal axis of the post; inserting into the longitudinal bore a tubular member having an upper end and a lower end with internal threads complementary to the threads of the rod, the tubular member defining a lower portion and an upper portion having a thinner wall thickness than that of the lower portion, the lower portion being sized to be received within the longitudinal bore with a friction fit therebetween, and the upper portion defining diametrically opposed planar longitudinal external surfaces; machining a transverse bore passing through a portion of the post and the planar longitudinal external surfaces of the upper portion; inserting a dowel rod into the transverse bore in a manner that the dowel rod passes through the upper portion of the tubular member; and threading the lower end of the tubular member onto the rod of the base and tightening thereof until the post is secured to the base and thereby to the construction surface.

2. The method of claim 1 wherein the threaded rod on the base is located at the center of the top portion.

3. The method of claim 2 wherein the threaded rod is perpendicular to the top surface.

4. The method of claim 3 wherein the base further includes a planar bottom surface opposite the top surface and a plurality of mounting holes extending from the top surface to the bottom surface, and the step of mounting onto the construction surface comprises securing the base to the construction surface with screws or bolts through the mounting holes.

5. The method of claim 4 wherein the mounting holes are countersunk with respect to the top surface so that heads of the screws or bolts are flush or below the top surface.

6. The method of claim 1 further comprising the step of mounting a support plate onto the bottom end of the post prior to the step of threading the lower end of the tubular member onto the rod, the support plate having a hole sized to accommodate the lower end of the tubular member, and the step of mounting the support plate includes aligning the hole with the longitudinal bore.

7. The method of claim 6 wherein the support plate includes one or more blades extending from one side of the support plate and the step of mounting the support plate comprises driving the blades into the bottom end of the post.

8. A post fastening device for mounting a post to a construction surface, the device comprising: a base having a planar top surface and a threaded rod extending from the top surface; a tubular member for insertion into a longitudinal axial bore on the bottom end of the post, the tubular member having an upper end and a lower end with internal threads complementary to the threads of the rod, the tubular member defining a lower portion and an upper portion having a thinner wall thickness than that of the lower portion; diametrically opposed planar longitudinal external surfaces defined on the upper portion to facilitate drilling of a transverse bore through a portion of the post and the upper portion when the tubular member is within the longitudinal bore; and a dowel rod for insertion into the transverse bore, the dowel rod being sized to pass through the upper portion and a portion of the post on both sides of the upper portion.

9. The device of claim 8 wherein the threaded rod on the base is located at the center of the top portion.

10. The device of claim 9 wherein the threaded rod is perpendicular to the top surface.

11. The device of claim 10 wherein the base further includes a planar bottom surface opposite the top surface and a plurality of mounting holes extending from the top surface to the bottom surface for receiving screws or bolts for mounting the base to the construction surface.

12. The device of claim 11 wherein the mounting holes are countersunk with respect to the top surface so that heads of the screws or bolts are flush or below the top surface.

13. The device of claim 8 further comprising one or more threaded levelling holes passing through the base from the top surface to the bottom surface and being adjacent an edge of the base, and a set-screw within the one or more levelling holes being flush or below the upper surface and operable to act against the construction surface to raise or lower the base relative to the construction surface to effect tilting of the rod.

14. The device of claim 13 further comprising a levelling plate for placement between the base and the construction surface to provide a rigid surface upon which the set-screw of the one or more leveling holes may operate.

15. The device of claim 13 wherein the support plate includes one or more blades extending from one side of the support plate for being driven into the bottom end of the post.

16. The device of claim 15 wherein the one or more blades is positioned around the periphery of the hole and no less than about away from the hole.

17. The device of claim 16 wherein the one or more blades includes a V cut on the leading edge to define pointed prongs to facilitate the impalement of the blade into the bottom end of the post.

18. The device of claim 8 further comprising a support plate having a hole sized to accommodate the lower end of the tubular member and adapted to being fastened onto the bottom end of the post with the hole aligned with the longitudinal bore.

19. The device of claim 8 wherein the wall thickness of the lower portion is at least .

20. The device of claim 19 wherein the wall of upper portion has a thickness of from about 1/16 to about .

21. The device of claim 8 wherein an external surface portion of the tubular member adjacent the lower end includes a reference mark vertically aligned with one or more of the planar longitudinal external surfaces.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference is made by way of example to the accompanying drawings in which:

(2) FIGS. 1 and 2 are perspective views of an embodiment on a post fastening device set within a solid wood post before and after the post and tube have been screwed onto the lower base where the base lies inside the periphery of the side walls of the post.

(3) FIG. 3 is a perspective view of an embodiment of the base of the post fastening device of FIG. 1 with the threaded rod in place.

(4) FIG. 4 is a cross sectional view along line A-A of the base of FIG. 3 showing the through holes for the threaded rod and fasteners as well as the welding cavities adjacent to the aperture for the rod.

(5) FIG. 5 is a top view of the base of the device in FIG. 3 depicting the fastener holes, set screw holes and aperture for the rod.

(6) FIG. 6 is a perspective view of an embodiment of a surface leveling plate.

(7) FIG. 7 is a cross sectional view of the tube of FIG. 1 depicting the interior threaded lower area, the tapered upper portion and the different wall thicknesses between the lower portion of the upper portion.

(8) FIG. 8 is a top plan view of the tube shown in FIG. 7.

(9) FIG. 9 is a perspective view of the transverse pin shown in FIG. 1.

(10) FIG. 10 is a perspective view of the wood plug shown in FIG. 1.

(11) FIGS. 11 and 12 are perspective views of another embodiment of a post fastening device directed to compression loads, prior to being attached to its base and after installation.

(12) FIG. 13 is a bottom plan view of the base shown in FIGS. 11 and 12.

(13) FIG. 14 is a side sectional view of the post fastening device shown in FIGS. 11 and 12.

(14) FIGS. 15 and 16 are a top and a side views of a wood structure installation plate.

(15) FIG. 17 is a side view of a wood post, tube, transverse locking pin, base, fasteners and wood installation plate on a deck.

(16) FIG. 18 is a perspective view of the wood post, hollow tube, transverse locking pin, base, fasteners and wood installation plate on a deck shown in FIG. 17.

(17) FIG. 19 is a perspective view of post fastening devices used in a deck and railing construction, one embodiment of the device being directed to lateral load resistance in the railing posts, and the other device being directed to compression load resistance in the deck support posts.

(18) FIG. 20 is a perspective view of post fastening device used in a fence construction being directed to lateral load resistance in the fence posts.

(19) FIG. 21 is a perspective view of post fastening device used in a shade sail construction being directed to lateral load resistance in the sail support posts.

(20) FIG. 22 is a perspective view of a tension bracket accessory.

(21) FIG. 23 is a perspective view of the tension bracket of FIG. 22 prior to being impaled into the end of the post.

(22) FIG. 24 is a perspective view of the tension bracket of FIG. 22 after having been impaled fully into the end of the post.

(23) FIG. 25 is a side cross section view of the tension bracket of FIG. 22 used the post fastening device of FIG. 1.

DETAILED DESCRIPTION

(24) For the purposes of promoting an understanding of the principles of the invention reference will now be made to the exemplary embodiment illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications of the inventive features illustrated herein, and any additional applications of the principles of the invention as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.

(25) Referring to FIGS. 1-10, there is depicted an embodiment of a post fastening device 100 in accordance with the present invention. The post fastening device 100 is comprised of three major components: a base member or base 105, a tubular member or tube 102, and at least one transverse locking pin 103. An optional surface leveling plate 114 may be provided. A solid wood post 1 is shown within which the device is installed.

(26) The base 105 is defined by a planar top surface 123, a bottom or lower planar surface 124 and vertical side walls 126, which in the illustrated embodiment form a square. Alternatively, the base member may be in any shape to match the cross-sectional dimensions of the post with which it is being integrated. For example, the base may be circular to fit a round post such as a log. It may also be rectangular to match a nominal 46 dimensional piece of lumber, and the like. In the illustrated embodiment, the base 105 is a unitary piece and may be made of either machined or cast metal or plastic.

(27) The upper planar surface 123 is recessed in at least four locations where fastener holes 107 are bored to accept either screws or bolts 122. The depth of the recess is sufficient to create a space 125 that permits the head of a fastener to sit below the plane of the upper surface 123 so as not to interfere with the bottom surface 2 of the post 1. This in turn permits the bottom surface 2 of the wood post to rotate until it is compresses tightly onto the upper surface 123 of the base 105 as is further described below herein. Threaded levelling apertures 108 are shown passing through the upper 123 and lower 124 surfaces of the base, proximate to the perimeter of the side wall 126 and between adjacent fastener holes 107. A set screw 115 may be inserted into the aperture 108 and adjusted to bring the upper planar surface 123 into horizontal level as desired on any given surface. The lower surface of the set screw makes contact with a flat surface upon which the base 105 is mounted, or the leveling plate 114 if such is used, which is defined by the same peripheral shape as the base above it.

(28) A threaded rod 106 extends from the upper surface 123 at the center of the base 105 and is oriented perpendicularly relative to the upper planar surface 123. One mode of making the threaded rod 106 is by providing a threaded aperture 113 in the center of the base 105 into which a threaded rod is screwed until the planar surface of its lower terminus is flush with the bottom planar surface 124 of the base. The rod 106 is then fixed in place and prevented from rotating by two precise welds which fill two cavities 112 formed within the lower planar surface 124 and the inner circumferential walls of the threaded aperture 113. There are other ways of providing the threaded rod 6 on the upper surface 123 of the base that are within the knowledge of the skilled reader.

(29) The tube 102 has an upper end and a lower end, and is defined in an upper portion 116 by diametrically opposed planar longitudinal external surfaces such as flat longitudinal surfaces 111 running along the length of the upper portion 116, which flat longitudinal surfaces 111 are separated by the adjacent longitudinal circumferentially rounded surfaces 110 of the tube. A transitional zone 120 separates the upper portion 116 from a lower cylindrical portion 117 of the tube, which is preferably has a thicker wall than the upper portion 116.

(30) The perspective view shown in FIG. 1 shows the tube 102, a longitudinal central bore or cylindrical cavity 141 within the post 1, a transverse dowel rod such as pin 103 that is installed into a transverse bored hole 121 within the wood post 1, and wood plug 104. The pin 103 passes through the tube 102 on the flat formed surface 111. Also shown is the bottom edge 128 of the tube 102, and one of two notches 109 defined at 180 degrees from each other along the circumferential bottom edge 128 of the tube 102. The lower inner walls of the tube are further defined by internal threads 138 (shown in FIG. 7) which mate with the threaded rod 106. The notches 109 are positioned along the circumference of the tube so that each notch 109 aligns with a flat surface 111 on the upper portion 116 of tube 102.

(31) FIG. 7 depicts a longitudinal sectional view of the tube 102 used for lateral load resistance devices and the varying wall thickness of the tube over the length of the tube. Characteristic of this tube is a thicker wall material in the lower portion 117 with a threaded portion 138 along the inside wall surface. The upper 116 and lower 117 segments of the tube are separated by the transitional zone 120. The wall thickness in the upper portion 116 is notably thinner than the lower portion 117. This thinner wall thickness makes it easier to form the flat surfaces 111. The flat surfaces 111 help a drill bit to locate and initiate cutting through the tube 102 as the bore 121 for the transverse bore pin 103 is drilled first through one side of the post, through the tube 102, and the other side post during installation. The thinner material of the upper portion 116 makes it easier for a drill bit to cut through yet still provide sufficient tensile strength while the post is under lateral load. In preferred embodiments, the wall of upper portion has a thickness of from about 1/16 to about . The thicker wall portion 117 of the tube ensures sufficient material for the threads 38 and maximum moment force resistance while the post is under lateral load. In preferred embodiments, the wall thickness of the lower portion is at least .

(32) Referring to FIGS. 11-15, another embodiment of a post fastening device 101 of the present invention is shown that is mainly directed to handling compression forces as opposed to lateral forces. The base 129 of a compression device 101 and tube 102a may vary from those parts used for a device intended for lateral load resistance such as device 100 in several ways. The base 129 may be fabricated from sheet metal or steel to reduce material cost. One pair of side walls 133 are shorter whereas the adjacent pair of side walls are longer and folded so as to form a flat surface 142 and then transitioning into upward sloping panels 134 that are welded to the underside of the top planar surface of the base 129 in order to fortify the compression resistance of the base. Four large circular holes 135 are formed in the top planar surface of the base, and directly below each of them defined in the flat panel 142 are smaller holes 136 through which screws 122 pass. The larger hole 135 allows the larger diameter head 143 of the screw 122 to fit through the top planar surface in order to enter the smaller holes 136 and ultimately fasten the base 129 securely to the surface. The upper end of the tube 102a is formed in a similar way as previously described the respective tube 102. However, a hexagonal nut 131 or circular plug with a threaded aperture 137 is fitted into the lower terminus of the tube and welded in place, said nut 131 is set slightly deeper into the tube 102a so that a weld can be made between the nut 131 and the bottom edge of the tube. The threaded aperture 137 functions similarly to the threaded inner walls 138 of the tube 102 described previously herein for use for lateral loads. The threaded aperture 137 mates with the threaded rod 130 which is connected to the base 129. The rod 130 is fitted with a nut 132 and passes upwardly through an aperture 139 defined in the center of the top planar surface of the base 129. The nut 132 is welded to the underside of the top planar surface of the base 129 and the rod 130 is welded to the nut 132 to prevent it from rotating.

(33) Referring to FIGS. 15-18, perspective and plan views of the tube 102, base 105, pin 103, fastening bolts 122 and plate 118 are depicted. The bolts 122 and plate 118 are used when the post fastening assembly is attached to a common wood joist framed structure. The thickness 119 of the plate 118 ensures that the nuts securing the bolts 122, which pass through holes 140, do not pull up into the wood blocking pieces that the bolts 122 pass through underneath the top surface deck material.

(34) The following describes both the characteristics of the post anchoring devices and the method of employing them.

(35) The first step is to install the hollow tube 102 into the post 1. This requires that the center of the bottom of the post be located by tracing diagonal pencil lines from corner to corner. A drill or boring auger of the same diameter as the tube 102 is used to bore a hole 141 from the center location into the post following the longitudinal center line of the post to a depth of about 1 further than the length of the tube 102. Depending on the length of the tube used, the bore can extend as little as three or four inches to as much as twelve to thirteen inches. The length of the tube may be varied depending on the intended use, from compression to moment load resistance. Shorter tube lengths may be better suited to compression load resistance whereas longer tube lengths may be better suited to moment load resistance.

(36) As described herein, the tube has a thicker wall at the lower portion 117 and threads 138 tapped into the inner wall surface, and the tube has a thinner wall at the upper portion 116 as well as flat outer surfaces 111 formed along the upper length of the tube such that a partial square shape is formed into the tube but leaving radius corners 110. The tube 102 is oriented to the bore in the post with the thinner walled end of the tube entering the bore 141 first. The flat surfaces 111 of the upper portion 117 of the tube should be aligned with the flat surfaces of the post walls. There are also reference marks such as notches 109 on bottom edge 128 of the tube which are positioned along the circumference of the tube so as to represent where the flat surfaces 11 of the tube are located inside the post once the tube is fully inserted.

(37) Once correctly oriented with the post, the tube 102 is inserted halfway into the bore 141 so that it can be determined with greater certainty what the exact line or path of the bore inside the post. This is a precautionary step because the hole can be bored slightly off the longitudinal center line of the post and therefore the path of the bore must be determined with sufficient certainty so that the user can determine where to drill through the post 1 in order to pass through the tube 102 to create the bore 121 in which to insert the transverse locking pin 103 or pins if more than one is use. This process is further described in the step that follows.

(38) Fortunately, even if the hole for the tube has been bored slightly off line, the line can be determined with a high degree of certainty. This is done by inserting the tube 102 halfway into the post 1 and taking a straight edge or ruler and observing the center line of the tube and then envisioning the line extending along the post. When the straight edge has been placed in the correct location on the face of the post such that the user is confident the edge is parallel to the center line of the bore inside the post, a pencil line is drawn along the length of the post to mark it. The post is then flipped 190 degrees onto its adjacent side and the process is repeated. The imaginary center line of the bore inside the post is now traced thus leaving two lines on adjacent sides of the post 1.

(39) Now the tube 102 can be inserted into the bore 141. To protect the threads of the tube 138, a bolt can be turned into the threads 138 and the user can strike the bolt to drive the tube 102 into the post 1 rather than exerting force near the threads 138. The tube 102 is carefully inserted so that the edge of the lower end or the tube is just below the flat planar surface 2 of the bottom of the post thereby leaving a small reveal. For example, for common softwoods the tube can sit about 1/16 to below the surface of the post bottom 2 to preserve aesthetics. For hardwoods the tube can be set flush to no more than about 1/16 below the surface 2 to preserve aesthetics.

(40) The next step is to prepare to drill the transverse hole 121 for the locking pin 103. If the post fastening assembly is designed for moment load resistance, it is common for two pins 103 to be inserted and thus the need to trace two lines on the post on adjacent faces of the post. Whereas, compression resistant designed assemblies typically only require a single pin 103. The location of the first pin 103 should be set by first measuring from the base 2 of the post 1 along the face of the post 1 the actual length of the tube 102 used and then marking the location one inch backward from the end of the tube. If a second locking pin 103 is needed, the same measurement is made along the second traced center line but the pin location is marked two inches backward from the end of the tube. Prior to drilling, a final check should be made to ensure that the flat faces 111 of the upper length 116 of the tube 102 are in fact parallel to the face of the post. This is easily done by observing the location of the notches 109 in the bottom edge 128 of the tube 102. In the event that the tube was mistakenly turned several degrees and now rests in the post so that the flat surfaces 111 which are to be drilled through for the pin 103 to pass are no longer parallel to the face of the post, the user can angle the drill to match the angle of variance of the flat surfaces 111 relative to the face of the post 1.

(41) The transverse bore 121 is drilled the same diameter as the locking pin 103 and to a length that is just short of the opposite face of the post from whence the drilling began. This creates a blind bore for the pin 103 to insert into, said pin being shorter than the width of the post 1 such that a small gap between the end of the pin 103 and the opening of the bore 121 on the face of the post 1 allows for a tapered plug 104 to be fitted and sanded flush with the surface of the post 1 completely hiding the pin 103 from view. Plugs can be made of various wood species to match the post as desired. The post is now ready and attention can be turned to attaching the base 105 or 129 to a concrete surface or a wood framed structure.

(42) The base 105 is set at the desired location on an approximately horizontal concrete or masonry surface and the corner through holes 107 can be used as a jig through which the user can drill holes into the concrete or masonry of the requisite diameter to match those of the concrete screws 122 or expansion bolts. Screws 122 are the preferred fastener as the heads 143 are lower profile and sit below the upper planar surface 123 and allow the flat bottom surface 2 of the post to turn above and not conflict with the screw heads 143. Prior to fastening the screws 122, the base 105 can be checked for level by using a small level and adjustments can be made by using common shims or by using the set screws 115 and the surface leveling plate 114. Once the base 105 is level, screws can be fastened and the plate secured to the surface. With tube 102 firmly secured inside the post 1, it can now be placed over the base such that the threaded rod 6 of the base 105 mates with the threads inside the tube 138. The post is turned at first by hand until the base surface 2 of the post 1 contacts the upper planar surface 123 of the base 105. In order to fully tighten the post on the base, it is recommended to use a makeshift wrench of dimensional lumber such as a 210 or larger with a square cut out from one end that can accept the shape of the post and thereby greater leverage can be generated in order to fully tighten the post.

(43) The objective is to tighten the post to the point that the tube is pulled down inside the bored cavity 141 so far as the locking pins 103 will permit and ideally such that the edge of the tube 128 which was intentionally set slightly below the bottom surface 27 of the post 1 is now as close to contacting the surface of the base 123 as possible. As those skilled in the art will appreciate, it would not be desirable for the edge of the tube 128 to fully contact the surface of the base 123 while the side walls of the post are not aligned with the side walls 126 of the base. For example, if the post was tightened to its apparent maximum extent because the tube bottom 128 had contacted the plate surface 123 but the post was still one eighth of a rotation from being square with the walls 126 of the base 105, it would be necessary to reverse the post slightly. This reversal might in some cases reduce the tension of the post 1 to the base 105 such that optimum performance is not achieved. Therefore, proper practice is to set the tube edge 128 into the bore 121 so that it is sufficiently below the surface of the bottom of the post so that once the base 105 and post bottom 2 contact each other the post can be further tightened several increments of quarter turns until it cannot be tightened further.

(44) The method for installing the compression post fastening device to a wood or composite surface over a wood framed structure will now be described. The main differences between the compression device and the lateral load resistance device as described previously is that the compression device uses a lighter weight base 129 of formed sheet steel and a lighter weight and shorter tube 102a. The base 129 is placed in a desirable location on a wood or concrete surface. In the case of a concrete surface the holes 136 defined in the flat bottom flange 142 of the base 129 can be used as a template for a drill bit to pass through to drill the screw holes. Screws 122 designed for either wood or concrete are fitted through the larger holes 135 defined on the upper planar surface 123 of the base 129 and driven down to secure the plate to the surface.

(45) The tube 102a having been inserted and secured into the post 1 by one or more locking pins 103 and hidden by plugs 104 is now located above the base 129 so that the threaded rod 130 is aligned with the threaded aperture 137 defined within the cylindrical disk or nut 131 welded to the inside walls of the tube 102a. The tube 102a and post 1 are turned tightly onto the upper remote terminus of the rod 130 pulling the base of the post 2 into tight contact with the upper surface 123 of the base 129. The rod 130 is firmly secured to the base 129 by virtue of it passing through aperture 139 in the top surface and the nut 132, said nut 132 being welded to the lower extremity of the rod 130 and the underside of the top planar surface 123 so that the lower remote terminus of the rod 132 meets the mounting surface providing an additional point for support, compression resistance and load dissipation. The resulting connection between the post 1 and the tube 102a and base 129 is similar in performance to a more obvious and visible external U shaped base using through bolts except this device has no external brackets or visible fasteners. This device is optimally designed for resisting compression and tension (uplift) forces yet provides an aesthetically improved appearance. Having described how both the lateral load and compression only resistant post fastening assemblies are installed to flat surfaces, a method for securing a lateral load resistant device to a wood framed structure will now be described.

(46) The base 105 is located in the desired location on the surface. In order to provide the stability required, it is common practice to install an approximately 3 piece of dimensional lumber and block it between the joists below each post location. This is usually accomplished by screwing together two pieces of 2 material such as 26 or 28. The blocking material is fitted precisely between the joists and pushed upwards until it contacts the underside of the decking boards. The blocking material is then screwed into place through each joist securing in place.

(47) Long carriage bolts 122 are fitted through drilled holes in the decking and the blocking and passing through slightly oversized through holes 140 in an installation plate 118 of sufficient thickness 119 to effectively resist deformation when the post 1 is under maximum load. The carriage bolts are secured to the installation plate 118 by washers and nuts. The washers and nuts are now prevented from being pulled up into the wood material and a more rigid connection with reduced post deflection is achieved.

(48) This is how the post fastening devices work and are secured to the various surfaces, whether it is for a lateral load resistant application or a compression and tension only application. The difference noted in the lateral load device is an overall tapering or reduction of wall thickness along its length from thickest at the lower remote terminus to thinner at the upper remote terminus combined with four flat planer surfaces. The change in wall thickness can be a continuous taper achieved by machining or discrete changes in wall thickness at certain points along the tube length. The thinner material and flat surfaces in the upper length make it easier for a user to initiate drilling on a flat rather than a round surface and to cut through it rather than a thicker round material.

(49) The moment generated will create a tension force on the side of the post where the load is applied and a compression force on the opposite side. The ability of the locking pin embedded within the wood fiber to resist this tension force is dependent upon the bending strength of the pin and the density of the wood. When the pin does not bend and the wood surrounding it is not compressed, the tube 102 remains stationary within the post 1 directing the load to the rod 30 and the carriage bolts 122 and the installation plate 18.

(50) An important aspect to the efficacy of the post fastening assembly for lateral load force resistance is the ratio of the length of the tube 102 to the length of the post 1. When observing any given length of post, the moment generated at the connection between the base 105 and the base of the tube 102 is a function of the ratio of the length of the tube to the post and can be expressed using the mathematical principles of a second class lever. For example, a 12 inch tube installed in a 36 inch post will result in a moment at the tube plate connection that is double the lateral force applied at the top of the post. The formula used to calculate the multiplier is expressed within the parentheses ((3612)/12=2). In this example a 500 lbs lateral load generates 1000 ft-lbs of torque. The shorter the tube, the greater the torque generated. A 6 inch tube generates 2500 ft-lbs of torque ((366)/6=5). Understanding this relationship helps illustrate that the less dense the wood fiber is, the lower the torque forces the post fastening assembly will resist before the remote end of the post begins to rotate over the remote end of the tube 102 within the post 1. Rotation is prevented only so long as the pin and the tube remain immobile within the post 1. This can be addressed by either increasing the density of the wood or increasing the length of the tube.

(51) This also means that the post fastening assembly can be further varied for different purposes so that it can be useful in fence post applications, pergolas, light standards or even shade sail support posts which must resist high tension forces at the remote ends of the posts. Each broad range of application will determine the specifications of the dimensions and form of each component part for the most efficient and economical performance.

(52) Referring to FIGS. 22 to 25, there is shown a support plate such as tension bracket 144 that may be used with a post fastening device of the present invention, such as post fastening devices 100 or 101. The tension bracket 144 comprises a planar member 143 and vertical blades or tabs 145 that extend perpendicularly upward from the planar member around a central aperture 147. The upper edge of the tabs 145 have a V cut 146 to define prongs 149 that facilitate impalement of the tabs 145 into wood post 1.

(53) The tension bracket 144 is an optional accessory that may be used with the post fastening device to raise the performance of softer wood posts such as western cedar and redwood to match that of harder softwoods like pine, spruce and hemlock. It accomplishes this by providing tensile resistance to counteract the opposing vertical compression and tension forces that are concentrated at the bottom of the post when the upper remote end of the post is under lateral load. These antagonistic forces transfer over to opposing horizontal forces and are expressed along the bottom surface of the post 1 and ultimately threaten to pull the post apart from the center of the post.

(54) The bracket 144 is aligned and located in such a way that the circumferential edge of the central aperture 147 is equidistant from the outside diameter of the circumferential edge of the tube 102 (or 102a) of the post fastening device 100 (or 101), as shown in FIG. 24, after the bracket 144 having been impaled into the end of the post. The aperture 147 is an important feature for the bracket to be used with the post fastening devices 100 or 101 given that the tube 102 or 102a is inset approximately 1/16 (lower) from the flat planar surface of the end of the post 2. This distance is determined by the pitch of the threads and is ideally set to account for at least 180 of additional rotation once the post bottom 2 contacts the upper planar surface 123 of the base. This allows for the tube to be pulled downward within this small gap and increase the tension force between the base 105 and the bottom 2 of the post 1. However, when the bracket 144 is used it is not necessary to set the tube 102 or 102a the full 1/16 lower than the end of the post given that the bracket itself is 1/16 thick. With applications that use the bracket, the tube may be set very nearly flush or about 1/32 below the bottom surface of the post.

(55) For optimal functioning, using the minimal amount of material, and to prevent the post walls from being prone to splitting, the distance from the peripheral post wall surface to the outside surface of the vertical tabs 145 is about for a 44 wood post. Preferably, the inside surface of the tabs 145 are no less than about from the outside wall of the tube 102. The V shaped zone 146 on the tab 145 facilitates the impalement of the sharp prongs 149 into the post. The tabs are impaled by striking each tab successively in a circular pattern so each tab descends into the post relatively equally to the other. Once firmly embedded into the post, the opposing forces acting to pull the post apart are counteracted by the tensile strength of the flat planar base of the bracket 144, which is also advantageously completely underneath the post and hidden from view.

(56) Other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.

(57) While the above description and illustrations constitute preferred or alternate embodiments of the present invention, it will be appreciated that numerous variations may be made, such as altering the perimeter shape, without departing from the scope of the invention. It is intended that the invention be construed as including all such modifications and alterations.