AU668653B2 - Improved post anchor and method - Google Patents

Description

I-

AUSTRALIA

Patents Act 668653 COMPLETE SPECIFICATION

(ORIGINAL)

Application Number: Lodged: Class Int. Class roo o 00 0 t -o o 0U 0 0p00 0( V Complete Specification Lodged: Accepted: Published: Priority Related Art: Applicant(s): PRYDA (AUST) PTY. LTD.

Department of Defence Anzac Park West CANBERRA A.C.T. 2600 Address for Service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled: "IMPROVED POST ANCHOR AND METHOD" Our Ref: IRN 334383 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 1 -2- IMPROVED POST ANCHOR AND METHOD The present invention relates to an improved post anchor and to a method for its manufacture.

A post anchor typically includes an upper post receiving element, a lower base element and an intermediate stem element. The post receiving element may include a U-shaped or saddle portion or an L-shaped or half-saddle portion or the like. In some variants such as centre pin and centre blade post anchors, the post receiving portion is reduced to a web with no sides but has a central rod swaged or blade welded across the centre of the web. The post receiving element is adapted to be fixed to a timber post or the like via screws, bolts or other fixing means. The base element includes a fixing/bearing portion and is typically adapted to be fixed to a support surface such as set concrete, masonry, paving, etc. via screws, bolts or other fixing means.

Where the base element is adapted to be fixed to a flat support surface, it generally comprises a flat element such as a plate. Alternatively, the post anchor may be a adapted to be fixed into cast concrete. In the latter case the base element may be substantially modified or it may be omitted. The intermediate stem element extends 25 between the upper and lower elements and has a length appropriate for a specific application.

Traditionally post anchors or post supports as they are known in the trade, are made by blanking or stamping the upper and lower elements, bending the upper elements into saddles or L-shaped angles if appropriate, welding the stem elements (typically of cylindrical form-tubular or solid bar) to the upper and lower elements, and then hot dip galvanizing or zinc plating the assembled products. The material of the elements generally comprises steel plate of 3 to 5mm gauge or thickness.

Strength of the assembled anchors is governed inter alia by stem diameter, welding quality, material thickness, bolt locations and size, form of anchorage and base 39 profile.

MJP V -3- The present invention seeks to provide an improved post anchor which may also be cheaper to manufacture.

It is found that an improved post anchor can be provided by use of cold upset joints, rather than welded joints. The cold upset joints may be produced with more consistent quality than is possible with welded joints, resulting in stronger joints and a more predictable performance for the assembled post anchor. The elements or parts may also be formed from a lower gauge and therefore cheaper material.

A cold upset joining process can enable some embodiments of the post anchor to be assembled reliably from pre-galvanized or pre-plated elements or parts. This Uo. may provide a significant cost advantage which can reduce 15 galvanizing/ plating costs by up to about 65 per cent.

Furthermore a cold upset joining process can be automated relatively easily, allowing low skilled labour to be used S:H° to assemble the post anchor, thereby reducing manufacturing costs.

Each stem element may include a tubular member and ~0may be fixed via cold upset joints to the upper and/or lower elements at respective ends thereof. The upper and/or lower elements may have respective apertures or *000 oo: openings formed therein. The apertures or openings may be 25 formed approximately centrally relative to the upper and lower elements and may substantially match the crossectional profile of the associated stem element. The ends of the stem element may be passed through the respective apertures of the upper and/or lower elements.

The ends of the stem element may be joined to the upper and lower element respectively via a cold upset process of which a preferred form will now be described.

The joining process may be carried out by means of opposed punches fitted to a swaging press or the like and actuated via hydraulic means. Each punch may include a projecting boss portion adapted to fit snugly into a respective end of the stem element. Where the stem element is circular in cross section, the boss portion may be substantially 39 cylindrical. Each punch may include an anvil portion

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4 depending substantially laterally from the boss portion.

The anvil portions may be adapted to engage the exposed edges of the stem element. The boss and anvil portions may be joined via a smoothly curved radius portion. Each punch may include a shoulder portion extending from the respective anvil portion and spaced from the respective boss portion.

In a preferred first stage of the joining process, the boss portion of each punch is inserted into a respective end of the tubular stem element, after each end is inserted through a respective aperture, until the ends o ~of the tubular element engage the radius portions of the Do punches.

In a second stage, pressure is applied to the o 15 punches so as to cause the ends of the stem element to be deformed via the radius portions and splayed out laterally against the respective anvil portions until they abut the shoulder portions. The splayed ends may overlie the upper and lower elements not unlike the heads of rivets.

Following abutment of the ends of the stem element against Sthe shoulder portions pressure may be transferred to the 0 middle of the stem element.

In a preferred third stage, a holding die is placed around the major surface of the stem element. Where the S 25 stem element is circular in cross section, the holding die may be substantially cylindrical. The holding die may include two or more parts such as two semi-cylindrical parts and these may be placed against the stem element to support it during the third stage. The holding die may support substantially the entire stem element. The holding die may be chamfered in regions adjacent the apertures formed in the upper and lower elements. The chamfered regions may be adapted to create, during the third stage flange receiving spaces for flanges to be formed in the stem element adjacent the apertures. Where the stem element is circular in cross section, each space may be substantially annular.

The length of the holding die may be substantially 39 equal to the length of the stem element after joining, but

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preferably is less than the length of the stem element before joining. During the third stage sufficient pressure may be applied to the punches to cause compressive deformation of the ends of the stem element.

During deformation, material of the stem element may be caused to flow into the flange receiving spaces to form the aforementioned flanges adjacent the apertures.

Where the stem element is pre-galvanized or .ppLf itod~ i is desirable that the chamfered regions be shaped so as to promote integrity of and/or avoid or at least minimize breaking through the plated or galvanized coating during compressive deformation of the ends of the element. In one form each chamfered region may include a substantially frusto-conical wall portion.

H o 15 Each end of the stem element may be compressively deformed with sufficient force such that each of the upper and lower elements is firmly held between a respective flange and splayed end of the stem element. Each of the aaa, flanges may be in the form of a continuo'is collar of larger outer lateral dimension than the associated aperture. Each of the splayed ends abutting the other side of a respective element may be in the form of a continuous ring of larger outer lateral dimension than the tassociated aperture.

S 25 To promote rigidity and enable load bearing capacity of the post anchor to be maintained with a lower gauge j material, reinforcing profiles such as ribs, bosses, wells and the like may be formed in the elements or parts. The I upper and lower elements may be stamped or blanked conventionally in any suitable manner and by any suitable means. In one form a punch press such as an 80 Ton Heine geared press may be used. Reinforcing profiles for strengthening the elements may be coined into the elements at the time of stamping or blanking or they may be formed separately.

The upper element may be substantially U- or saddle-shaped and may include laterally and/or longitudinally oriented reinforcing ribs, bosses or wells formed at least in a web portion of the element. The ribs/bosses/wells may be stamped or coined into the web portion of the upper element. In one form at least a first longitudinally oriented (ie. parallel to the legs of the U or saddle) boss may be coined in the web portion.

The boss may provide reinforcement against lateral distortion of the web portion. The projecting surface of the boss may be directed away from the stem element. The boss may occupy approximately 60% of the area of the web portion. The boss may be symmetrically oriented relative to the aperture formed in the web portion of the upper element. The aperture preferably is formed within the confines of the boss.

Alternatively or additionally one or more laterally oriented ribs may be coined in the web portion parallel to its free edges. The ribs may provide reinforcement against longitudinal distortion of the web portion. Each rib nay be positioned between the aperture and respective free edge. In one form each rib may occupy approximately 14% of the area of the web portion. The areas of the ribs and boss may be overlapped. The height of the ribs beyond the surface of the web portion (the stem receiving o aperture may be formed in the latter) may be at least substantially equal to the height of the splayed end of .444 .the stem element beyond the surface of the web portion.

a. 25 This may assist in distributing more evenly the weight or force of a post over the splayed end and ribs.

The lower element may comprise a substantially rectangular flat plate and may be oriented such that its longer side is parallel to the longer side of the web portion of the upper element. The lower element may be smaller than the web portion of the upper element. In one form the lower element may comprise approximately 60% of the area of the web portion of the upper element. The lower element may include laterally oriented reinforcing ribs. The ribs may provide reinforcement against longitudinal distortion of the lower element. The ribs may be directed away from the stem element. The height of the ribs beyond the surface of the lower element in which 39 may be formed the stem receiving aperture, may be such

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7 that it is substantially equal to the height of the splayed end of the stem element beyond the surface of the lower element. This may assist in distributing the weight of the anchor and pist over the splayed end and ribs.

Fixing apertures for bolts, screws and the like may be provided in the upper and/or lower elements. For example, apertures may be provided in the legs of a U-shaped upper element. The apertures may be provided in each leg aligned with each other so that bolts may pass therethrough. Alternatively the apertures may be offset so that coach screws may be used. The fixing apertures aO may be in the range 9-13mm diameter. In order for the bolts/screws to perform at an optimum value the fixing o apertures preferably are located between 6-9 diameters S 15 from the top of the web portion of the upper element.

Fixing apertures in the base element preferably are provided as close as possible to the stem element to promote maximum capacity of strength for the base element.

Where the post anchor is to be fixed into cast concrete the base element may be dispensed with. The end of the stem element opposite the upper element may be expanded so that it can be easily pushed in a cementslurry. The expanded end may be similar to a splayed stem end but without the presence of the base 25 element. Alternatively the expanded end may be conically flared or otherwise shaped to resist removal from concrete after it has set. Forming of the expanded end may be similar to the cold upset process performed at the upper element but the process occurs without the presence of a base element. Preferably the punch opposite the upper element is modified for forming the expanded end. The holding die may also be modified at the end opposite the upper element to mate with the modified punch.

According to one aspect of the present invention there is provided method of joining one end of a tubular element to a flat element or the like with the aid of a punch tool and a holding die, said tool having a projecting boss portion, an anvil portion depending 39 laterally from said boss portion and a shoulder portion

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Dn-- 8 extending from said anvil portion and spaced from said boss portion, said holding die having a longitudinal bore for receiving said tubular element and having an axially enlarged region adjacent one end of said bore, said method including the stepsof: forming an aperture in said flat element which substantially conforms to the external profile of said tubular element; passing said one end through said aperture; fitting said boss portion into said one end and applying pressure to said tool to cause said one end to splay laterally against one side of said flat element i' °°until it abuts said shoulder portion; placing said holding die around said tubular element with said enlarged region adjacent the other side of said flat element and applying further pressure to said tool to cause material of said tubular element to flow into said enlarged region to form a flange adjacent said other side o of said flat element.

According to a further aspect of the present invention there is provided method as described above wherein a further punch tool is provided for joining the other end of said tubular element to a further flat S•element or the like, said holding die having a further S 25 axially enlarged region near the other end of said bore and wherein: said forming step includes forming a further aperture in said further flat element; said passing step includes passing said other end of said tubular element through said further aperture; said fitting step includes fitting the boss portion of said further tool into said other end; said applying step includes applying pressure to said further tool to cause said other end to splay against one side of said further flat element until it abuts the shoulder portion of said further tool; said placing step includes placing said further axially enlarged region adjacent the other side of said 39 further flat element; and A o i

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PVTd 9 wherein said further applying step causes material of said tubular element to flow into said further enlarged region to form a further flange adjacent said other side of said further flat element.

According to a still further aspect of the present invention there is provided a structural product including a flat element and a tubular element joined thereto according to the method described above.

According to a still further aspect of the present invetnion there is provided a post anchor including a post o° receiving element and a stem element joined thereto according to the method described above. The post anchor may further include a base element joined to said stem element according to the method described above.

According to a still further aspect of the present invention there is provided a structural product including a flat element and a tubular element, said flat element having an aperture in which is received one end of said tubular element, said one end being splayed laterally against one side of said flat element and said tubular o element having a flange formed therein abutting the other side of said flat element.

According to a still further aspect of the present o invention there is provided a post anchor including a post a, 25 receiving element and a tubular stem element, said post receiving element having an aperture in which is received one end of said tubular element, said one end being splayed laterally against one side of said post receiving element and said stem element having a flange formed therein abutting the other side of said post receiving element.

The post anchor may further include a base element, said base element having a further aperture in which is received the other end of said tubular element, said other end being splayed laterally against one side of said base element and having a flange formed therein abutting the other side of said base element.

A preferred embodiment of the present invention will 39 now be described with reference to the accompanying

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10 drawings wherein:- Figs. lA-IC show one form of upset joining process according to the present invention; Figs. 2A-2D show front and side views in partial section, and plan and inverted plan views respectively of one form of post anchor according to the present invention; Fig. 3 shows a perspective view of the post anchor of Fig. 2; Figs. 4A-4D show front and side views in partial sectio,, and plan and inverted plan views respectively of another form of post anchor according to the present ,invention; and 5 shows a perspective view of the post anchor 'o of Fig. 4.

J 15 Referring to Figs. lA-IC, the cold upset joining process is commenced by passing the ends 10, 11 of tubular stem element 12 through apertures formed in the upper and lower elements 13, 14. Figs. lA-IC show in cross section o punches 15, 16. Punches 15, 16 are fitted to a swaging press (not shown). Punch 15 includes boss portion 17, anvil portion 19, and shoulder portion 21; while punch 16 o has similar respective portions 18, 20 and 22. Boss portions 17, 18 are joined to the respective anvil *000 portions 19, 20 via smoothly curved radius portions 23 and 4 25 24.

In a first stage of the joining process, each boss portion 17 and 18 is inserted into a respective one of ends 10, 11 of stem element 12 until ends 10, 11 engage the respective one of radius portions 23, 24 as shown in Fig. 1A. In a second stage pressure is applied to punches 16 in the direction of the arrows, causing ends 10, 11 to deform and splay as shown in Fig. lB. Continued application of pressure causes ends 10, 11 to form a splayed ring abutting shoulders 21, 22 of punches 15, 16.

Following abutment of ends 10, 11 against shoulders 21, 22 pressure from punches 15, 16 is transferred to 'the middle of stem element 12.

In a third stage, a holding die 25 comprising two 39 semi-cylindrical parts 26, 27 is placed around stem

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11 element 12 as shown in Fig. IC. The length of holding die is substantially equal to the distance between upper and lower elements 13, 14 in the finished product.

Holding die 25 includes chamfered substantially frusto-conical annular regions 28, 29 adjacent the apertures in upper and lower elements 13, 14. Chamfered regions 28, 29 create annular flange receiving spaces between holding die 25 and stem element 12 adjacent upper and lower elements 13, 14 for flanges to be formed in stem element 12. Regions 28, 29 are positioned so that a respective flange will be formed against the side of each of the upper and lower elements 13 and 14 which faces away f; "from the respective splayed end 10, 11. Thus each of I elements 10 and 11 is gripped tightly between the respective end 10, 11 and one of the flanges.

At the time when pressure is transferred to the l middle of stem element 12 the length of holding die 25 is less than the dist. -e between upper and lower elements °13, 14. Application or pressure to punches 15, 16 after transfer of pressure to the middle of stem element 12 causes the material of stem element 12 to flow into the abovementioned annular regions, creating pressure flanges in stem element 12 adjacent upper and lower elements 13, 14 as shown in Fig. 1C.

In an alternative embodiment holding die 25 may be placed around stem element 12 during the first stage of the joining process, and may be maintained in place around stem element 12 throughout or substantially throughout the joining process.

Figs. 2A-2B show flanges 30, 31 and splayed ends 32, 33 formed against the upper and lower elements 13, 14 in the finished post anchor. The web portion 34 of upper element 13 includes a pair of upwardly convex reinforcing ribs 35, 36 coined parallel to its free edges as shown, in any suitable manner and by any suitable means. The uppermost level of the ribs 35, 36 preferably is substantially equal to the uppermost level of splayed end 32 to assist in distributing more evenly the weight or 39 force of a post over the splayed end and ribs. Lower

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MJP .i 12 element 14 includes four downwardly convex reinforcing ribs 37-40 coined therein as shown.

Figures 4-5 show a further embodiment of the post anchor in which like parts are consistently referenced.

The further embodiment differs from the embodiment shown in Figs. 2-3 in that it includes an upwardly convex rectangular boss 41 coined in web portion 34. Boss 41 provides reinforcement against lateral distortion of web portion 34. Boss 41 overlaps into the region of reinforcing ribs 35, 36. Boss 41 may be coined in web portion 34 before, after or together with ribs 35, 36.

Finally, it is to be understood that various alterations, modifications and/or additions may be introduced into the constructions and arrangements of 15 parts previously described without departing from the spirit or ambit of the invention.

0 0 6o 0o 6 39

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Claims (14)

1. Method of joining one end of a tubular element to a flat element or the like with the aid of a punch tool and a holding die, said tool having a projecting boss portion, an anvil portion depending laterally from said boss portion and a shoulder portion extending from said anvil portion and spaced from said boss portion, said holding die having a longitudinal bore for receiving said tubular element and having an axially enlarged region adjacent one end of said bore, said method including the steps of: forming an aperture in said flat element which substantially conforms to the external profile of said tubular element; passing said one end of said tubular element through said aperture; fitting said boss portion into said one end and applying initial pressure to said tool to cause said one end to splay laterally against one side of said flat element until it abuts said shoulder portion; placing said holding die around said tubular element with said enlarged region adjacent the other side of said flat element and applying further pressure to said tool to cause material of said tubular element to flow into said enlarged So.. region to form a flange adjacent said other side of said flat element. 20

2. Method according to claim 1 wherein said step of placing said holding die around said tubular element is performed prior to applying initial pressure to said tool.

3. Method according to claim 1 or 2 wherein said flat element includes a web of a post receiving element and said tubular element includes a stem element. 4 4

4. Method according to claim 1, 2 or 3 wherein a further punch tool is provided for joining the other end of said tubular element to a further flat element or the like, said holding die having a further axially enlarged region near the other end of said bore and wherein: said forming step includes forming a further aperture in said further flat element; said passing step includes passing said other end of said tubular element through said further aperture; MJP CWNWORDAREGANODEL68c. K'/T O 'N' -14- said fitting step includes fitting the boss portion of said further tool into said other end; said applying step includes applying pressure to said further tool to cause said other end to splay against one side of said further flat element until it abuts the shoulder portion of said further tool; said placing step includes placing said further axially enlarged region adjacent the other side of said further flat element; and wherein said further applying step causes material of said tubular element to flow into said further enlarged region to form a further flange adjacent said other side of said further flat element.

Method according to claim 4 wherein said further flat element includes a base element.

6. Method according to any one of the preceding claims wherein said tubular element is cylindrical and said aperture is circular,

7. Method according to any one of the preceding claims wherein said boss and shoulder portions of said tool are joined via a smoothly curved portion,

8. A structural product including a flat elemrnent and a tubular element joined thereto according to the method of claim 1.

9. A post anchor including a post receiving element and a stem element o 20 joined thereto according to the method of claim 1.

10. A post anchor according to claim 9 including a base element joined to said 0 0 stem element according to the method of claim 4.

11. A post anchor according to claimrn 9 or 10 wherein said post receiving ool"oelement includes a reinforcing boss and/or one or more reinforcing ribs coined 025 therein.

12. A post anchor according to claim 11 wherein said base element includes one or more reinforcing ribs coined therein.

13. A method of joining one end of a tubular element to a flat element or the like substantially as herein described with reference to the accompanying drawings. MJP C:%WINWORDQRIE ABNODEL878 C.DOC j i I UI L cl*q

14. A method of joining the ends of a tubular element to respective flat elements or the like substantially as herein described with reference to the accompanying drawings, A post anchor substantially as herein described with reference to Figs, 2A to 2D and Fig. 3 or Figs. 4A to 4D and Fig. 5 of the accompanying drawings, DATED: 7 March 1996 PHILLIPS ORMONDE FITZPATRICK Attorneys for: PRYDA (AUST.) PTY. LTD. 0P0 *II SI SO 00 MJP C:W N"JOROMARICGA6NOOEL'487B 6C OC Lj.LU lquduv w 5 nu sizeB, orim or ancnorage and base 39 profile. MJP i ABSTRACT A method of joining one end (10,11) of a tubular element (12) to a flat element (13,14) or the like is disclosed. The method is performed with the aid of a punch tool (15,16) and a holding die The tool (15,16) has a projecting boss portion (17,18), an anvil portion (19,20) depending laterally from said boss portion (17,18) and a shoulder portion (21,22) extending from said anvil portion (19,20) and spaced from said boss portion (17,18). The holding die (25) has a longitudinal bore for receiving said tubular element (12) and an axially enlarged region (28,29) adjacent one end of said bore. The method includes the step of: forming an aperture in said flat element (13,14) I which substantially conforms to the external profile of said tubular element (12); passing said one end (10,11) through said aperture; fitting said boss portion (17,18) into said one end (10,11) and applying pressure to said tool (15,16) to cause said one end (10,11) to splay laterally against one side of said flat element (13,14) until it abuts said shoulder portion (21,22); placing said holding die (25) around said tubular element (12) with said enlarged region (28,29) adjacent the other side of said flat element (13,14) and applying further pressure to said tool (15,16) to cause material of said tubular element (12) to flow into said enlarged region (28,29) to form a flange adjacent said other side of said flat element (13,14). A post anchor including a stem element (12) and a post receiving element (13) and base element (14) joined thereto according to the above method is also disclosed. 39 MJP