AU704333B2 - An anchoring apparatus for solid elements - Google Patents

Description

S F Ref: 321923

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: FRe Corf(ri uc-ior S kears pE L*3d.

Alan Reid Pty Ltd A4-n44-- Park Nepw South Ha4-e-s 2-1-4- -AU&TRAUA- L A\ 14) 350 Co\i;r Cv ,eQ Rodney Mackay Sim Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia An Anchoring Apparatus for Solid Elements ASSOCIATED PROVISIONAL APPLICATION DETAILS [31] Application No(s) [331 Country PM9817 AU [323 Application Date 2 December 1994 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5815

I

AN ANCHORING APPARATUS FOR SOLID ELEMENTS BACKGROUND OF TIHE INVENTION The present invention is directed towards the field of anchoring devices cast in solid elements which are used for lifting the solid elements. In particular, anchors are used for lifting solid or hardened cast materials such as concrete, plaster, etc.

Prior art anchors typically include a lifting head, a shank, and a fastening component. The lifting head and the fastening component are located at opposite ends of the shank. The fastening component can be a "foot" which is essentially a metal flange orthogonally extending from the shank at a distal end. The foot has a larger dimension than the diameter of the shank. Such anchors are commonly made from forged metal, although other suitable materials and fabrication processes can be used.

Such an anchor is embedded in a solid element adjacent to an end of the solid element so that the anchor is longitudinally disposed substantially equidistant from an upper and lower surface which are substantially parallel to the longitudinal axis of the 15 solid element. In particular, the lifting head and a portion of the shank extend out of the solid element into a recess formed in the end of the solid element. Access is thereby provided to the lifting head so that it can be grasped for the purpose of lifting the solid element.

However, lateral forces applied to the anchor when lifting the solid element can produce fractures and other defects in the vicinity of the recess where the shank extends from the solid element and the fastening component.

Another prior art anchor incorporates an eye-hole in the fastening component for coupling the anchor to a reinforcement bar in the solid element by passing the reinforcing bar through the eye-hole. Thus, where loads exceed the fracture strength of the solid element, the load carrying capacity of the anchor can be enhanced by using the reinforcement bar with the anchor. While use of the reinforcing bar provides additional lifting strength in comparison to an anchor alone, pivoting forces between the reinforcing bar and the anchor induced by lateral forces applied to the anchor also (N Wbtc100438 DOC:SDO c 'g '1 111111 produce fractures and other defects in the solid e!-ment around the recess and the fastening component.

A further prior art anchor is a "foot-eye" anchor incorporating both a foot and an eye-hole in the fastening component. Such an anchor can be used with or without a reinforcing bar. A reinforcing bar can be passed through the eye-hole to provide additional lifting strength. Fractures and other defects can also be produced in the solid element due to pivoting forces as described above.

In yet another prior art "foot-eye" anchor, a shallow groove or guide strip is incorporated in the top surface of the foot to prevent sliding of the reinforcement bar during moulding and to reduce rocking play. The groove is partially circular to receive the circular reinforcement bar. However, this prior art anchor does not prevent rotation between the anchor and the reinforcement bar, and pivoting forces can be induced between them in response to lateral forces applied to the lifting head. This prior art anchor has the same disadvantages described above.

1 A further disadvantage of conventional anchors having a foot is the effect of "rifting" and poor compaction in concrete structures as will be described with reference Figs. 10A and 10B. Rifting occurs due to the lack of compaction of the concrete when making a concrete structure, and in particular concrete pipes. As shown in Fig. concrete is poured into a mould 1002 as indicated by arrow 1004 while the mould 1002 is rotated in the direction indicated by arrow 1008. The centripetal forces generated by rotation of the mould 1002 in the direction 1008 causes the concrete 1004 to move radially outward. As generally indicated by circle 1006, an anchor 1012 having a foot can be embedded in the pipe being fabricated by connecting the anchor 1012 to the mould 1002 as shown in the drawing.

2 5A more detailed view of the anchor 1012, the mould 1002 and the concrete 1004 indicated by circle 1006 is provided in Fig. 10B. The essential direction of flow and movement of concrete is in the direction indicated by the arrows 1014. The arrows 1014 indicate the flow of concrete due to the centripetal forces generated by rotation of the mould 1002. Arrows 1016 indicate the circular flow of concrete resulting from the INlbcc1004 38 DOC SOB I c rotation of mould 1002 in direction 1008. Because the radially outward flow 1014 of concrete in the vicinity of anchor 1012 is blocked by the bottom surface of the foot of the anchor 1012, the worst area of rifting and lack of compaction occurs in the regions indicated by hatching 1018 and 1020. Rifting essentially produces defective portions of the concrete structure that arise due to lack of compaction during the moulding process.

In particular, the worst area 1020 occurs in the lee of the anchor foot and shaft thereby resulting in bony concrete. The areas of bony concrete 1018 and 1020 due to lack of compaction result in the anchor 1012 not being properly anchored in the fabricated structure. Thus, when the concrete hardens and an attempt is made to lift the concrete 1 o structure by grasping the head of the anchor 1012 the defecting portions 1018 and 1020 of the concrete structure may collapse and disadvantageously allow play of the anchor 1012 in the concrete structure.

Thus, a need clearly exists for an anchor that overcomes the disadvantages of the prior art by reducing fractures and other defects in the solid element resulting from lateral forces applied to the anchor.

SUMMARY OF THE INVENTION In accordance with a first aspect of the invention, there is provided an anchoring apparatus for lifting a rigid body of material, wherein said apparatus is embedded in said body, said apparatus comprising: a shank; attachment means at one end of said shank for use to grasp said anchoring .apparatus; and "a foot at the other end of said shank, wherein a dimension of said foot transverse to the longitudinal axis of said shank is greater than the orresponding dimension of said shank, said foot formed to have one or more cut-out recesses through said foot for receiving a reinforcement means, wherein said shank incorporates an aperture adjacent to the othei enid of said shank for further receiving said reinforcing means, and IN ,bcI100438 DOCSDB.TCW further wherein said shank, said attachment means and said foot are integrally formed as said apparatus.

In accordance with a second aspect of the invention there is provided an anchoring apparatus for lifting a rigid body of material, wherein said apparatus is embedded in said body, said apparatus comprising: a shank; attachment means connected to one end of said shank for use to grasp said anchoring apparatus; and at least two laterally projecting elongated feet connected to the other end of 1o said shank and substantially forming a Tee-type structure for engaging a section of reinforcing means looped about said shank, wherein said shank, said attachment means, and said at least two feet are integrally formed as said apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiment of the invention is described with reference to the drawings: Figs. 1A-1C are side elevation-, front elevation-, and bottom-view diagrams of i th preferred embodiment of the invention; and Figs. 2A-2C are side elevation-, front elevation-, and bottom-view diagrams S* illustrating the anchor of Figs. 1A-IC disposed within a solid element.

Figs. 3 and 4 are bottom-view diagrams of first and second alternate embodiments; Figs. 5A-5C are side elevation-, front elevation-, and bottom-view diagrams of a third alternate embodiment of the invention; Figs. 6A and 6B are diagrams illustrating the fastening of a reinforcement bar to the anchor of the third alternate embodiment; Figs. 7A and 7B are side and front elevation-view diagrams illustrating the anchor of Figs. 5A-5C disposed within the solid element; Fig. 8 is a bottom-view diagram of a fourth alternate embodiment; IN ,bCcl O'J438 DOC:SDB TCW

I

Figs. 9A-9C are bottom-, side elevation-, and front elevation-view diagrams illustrating the fifth alternate embodiment; Figs. 10A and 10B are side and detailed side views of a concrete structure having an embedded conventional anchor; and Figs. 11A and 11B are side and bottom views of a sixth alternate embodiment embedded in a concrete structure being fabricated.

DETAILED DESCRIPTION .e o*

S

S

S a e e IN 'ltl:c00438 DOC SDB:TCW The anchor 10 of the preferred embodiment shown in Figs. 1A-1C takes the form of a lifting head 11 coupled to an eye-hole segment 14 by an intermediate shank 12.

Th eye-hole segment 14 has an eye-hole 13 for threading a reinforcing bar (23 in Figs 2A-2C) through the anchor 10. Beyond the eye-hole 13 is a substantially circular lifting foot 15 which orthogonally extends in a radial manner in relation to the longitudinal axis of symmetry of the anchor In the preferred embodiment, two recesses 16 are formed in the foot 15 with one on each of the opposite sides of the shank 12. This is illustrated by a dashed line in Figs. IA and 1C where the two recesses 16 are mirrored on opposite sides of the X-X' axis. The walls of the recesses 16 are substantially parallel to the longitudinal axis of the anchor 10 while the respective inner sidewalls of the recesses 16 are substantially flush with the surface of the shank 12.

The anchor 10 incorporates the recesses 16 in the foot 15 to form an interrupted lower "foot" that prevents rotation of the anchor 10 about the reinforcement bar, as described below.

While the drawings indicate that the inner sidewalls of recesses are substantially flush with the surface of the shank, it would be apparent to a person skilled in the art that one or more recesses can be incorporated in the foot which have o recess walls that are substantially parallel to the longitudinal extent of the anchor without departing from the scope of the invention.

The anchor 10 shown in Figs. 2A-2C is substantially disposed within a solid concrete slab 22 which has an in situ end 20 and a recess 21 (indicated by a dashed line in Figs. 2A and 2C). The slab 22 has its smallest extent between its substantially parallel surfaces 24 and The anchor 10 incorporates an interrupted lower foot 15 having recesses 16.

After the reinforcement bar 23 is threaded through the eye-hole 13 of the anchor 10, the reinforcement bar 23 is closed tightly against the inner sidewalls of the recesses 16 as shown in Figs. 2B and 2C. The sections of the reinforcement bar 23 extending from IN ,hb.cc100438,DOC:SDB the eye-hole 13 are thereby confined in the recesses 16 on either side of the foot 15 of the anchor The walls of recesses 16 prevent rotation of the anchor 10 about an axis 26 (shown by a dashed line) through the anchor 10 and the reinforcing bar 23. Thus, the anchor 10 shown in Figs. 2A-2C directly transfers rotational loads to the reinforcing bar 23 due to the coupling between the recesses 16 and the reinforcing bar 23.

The sidewalls of recesses 16 orthogonal to the surface of shank 12 oppose the pivoting motion (indicated by the double-headed arrow in Figs. 2A and 2C), and the surface of the reinforcement bar 23 directly interacts with the walls of recesses 16.

Twisting of the anchor 10 about the longitudinal axis of the shank 12 is also resisted.

A first alternate embodiment of the anchor 10 shown in Fig. 3 incorporates a single recess 18 in the circular lifting foot 15. As described, the walls of the recess 18 act to prevent rotation of the anchor 10 in relation to the reinforcing bar 23 (not shown in Fig. 3) and transfers rotational loads to the reinforcing bar 23. In addition, the recess 18 acts to prevent twisting of the anchor 10 about the longitudinal axis of the shank 12.

A second alternate embodiment of anchor 10 shown in Fig. 4 incorporates an interrupted foot 19 that is essentially semi-circular in shape. The foot 19 has a straight edge 19A that is flush with the shaft 12 and a semi-circular edge 19B. The interrupted foot 19 also acts to resist twisting of the anchor 10 about the longitudinal axis of the i shank 12 in relation to the reinforcing bar 23 (not shown in Fig. While the second embodiment shown in Fig. 4 incorporates a semi-circular foot 19, it would be apparent to a person skilled in the art that the interrupted foot 19 could comprise one or more alternately shaped edges for engaging the reinforcing bar 23 to prevent pivoting motion between the anchor and the reinforcing bar and to resist twisting motion of the anchor The stiffness of an anchor system incorporating the anchor is significantly improved due to the incorporation of recesses and discontinuous surfaces in the interrupted foot, and it acts to reduce the risk of failure of the slab around the anchor.

IN khbccIOO438.DOC:SDB he anchor 30 of the third alternate embodiment shown in Figs. 5A-5C takes the form of a lifting head 31 coupled to a fastening component by an intermediate shank 32.

The fastening component consists of a pair of laterally projecting feet 35A and 33B transversely extending from the shaft 32. In the third alternate embodiment, the two laterally projecting feet 35A and 33B are disposed one on each of the opposite sides of the shank 12. This is illustrated by a dashed line in Figs. 5A and 5C where tilhe two laterally projecting feet 35A and 33B are oriented on the Y-Y' axis. The laterally projecting feet 35A and 33B are substantially parallel to the longitudinal axis of the anchor The laterally projecting feet 35A and 33B are substantially "fin-shaped", i.e., the length and width of each foot 35A and 33B are fixed whereas the height is larger adjacent to the shank 32 than at the terminal end of the laterally projecting foot. It oeeoi would be apparent to a person skilled in the art that alternately shaped laterally projecting feet can be utilised without departing from the scope of the invention. For example, laterally projecting feet 35A and 33B can be used having a constant crosssection, a circular, rectangular, or square cross-section. in effect, the shank 32 and the laterally projecting feet 35A and 33B form a T-shaped structure.

The anchor 30 incorporates the laterally projecting feet 35A and 33B to form a third alternate embodiment that prevents rotation of the anchor 30 about the reinforcement bar as described below. The anchor 30 is fastened to a reinforcing bar 34 as shown in Figs. 6A and 6B by twisting the reinforcing bar 34 about the fastening component of anchor The fastening component of the anchor 30 shown in Fig. 6A is disposed within a looped segment of the reinforcing bar 34. The laterally projecting feet 35A and 33B are oriented so that the two feet 35A and 33B essentially form a shoulder to suspend the looped segment of the reinforcing bar 34 thereon. Reinforcing bar 34 can then be twisted to fasten the reinforcing bar over the laterally projecting feet 35A and 33B to secure anchor 30 to the reinforcing bar 34. This can be done by securing the [N hbcl10OO438.DOC'SD reinforcing bar 34, and then rotating the anchor 30 about its longitudinal axis to provide the twisted portion of the reinforcing bar 34 shown in Fig. 6B.

The anchor 30 shown in Figs. 7A and 7B is substantially disposed within the solid concrete slab 22 which has an in situ end 20 and a recess 21 (indicated by a dashed line in Fig. 7A). Again, the slab 22 has its smallest extent between its substantially parallel surfaces 24 and The reinforcing bar 34 is fastened to the anchor 30, as described above.

The laterally projecting feet 35A and 33B prevent rotation of the anchor 30 in at least one direction about the axis 36 between the anchor 32 and the reinforcing bar 1o 34 (indicated by a dashed line). Thus, the anchor 30 shown in Figs. 7A and 7B can transfer rotation loads to the reinforcing bar 34 due to the coupling between the anchor 30 and the twisted portion of the reinforcing bar 34. As mentioned above, the reinforcing bar 34 provides additional lifting strength. In addition, twisting of the anchor 30 about the longitudinal axis of the shank 32 is also prevented due to the coupling between laterally projecting feet 35A and 33B and the twisted portion of the reinforcing bar 34. The stiffness of an anchor system incorporating the anchor 30 is also significantly improved due to the use of the laterally projecting feet 35A and 33B coupled to the reinforcing bar 34, and it acts to reduce the risk of failure of the slab 22 around the anchor ,o A fourth alternate embodiment shown in Fig. 8 incorporates a lifting foot that has a recess 36. As described above, a reinforcing bar 34 can be twisted about the shaft 32 of the anchor 30 and a segment of the reinforcing bar 34 can be pressed into recess 36. The recess 36 can then be used to prevent pivoting motion between the anchor 30 and the reinforcing bar 34 and to resist twisting of the anchor A fifth alternate embodiment shown in Figs. 9A-9C incorporates a semicircular interrupted foot 37 in the anchor 30. As described above, reinforcing bar 34 can be twisted about the shaft 32. Preferably, the reinforcing bar 34 is twisted so that the crossed sections of the reinforcing bar 34 are in contact with the surface of the interrupted foot 37 defined by the straight edge 37A. Thus, the anchor 30 acts to [N I 00438.OC SCDB prevent pivoting motion between the anchor 30 and the reinforcing bar 34, and to resist twisting of the anchor A further advantage of the present invention is that it greatly increases compaction of concrete during the fabrication of a concrete strut,-' re. This is indicated S in Figs. 11A and 1 !B which are side and bottom views of a sixth alternate embodiment of the invention. While the invention will be described with reference to the sixth alternate embodiment, it will be apparent to a person skilled in the art that the description is equally applicable to the preferred, second, third, fourth and fifth embodiments of the invention.

As shown in Fig. 11A, the anchoring apparatus 1106 according to the sixth alternate embodiment has an interrupted foot and is connected to the mould 1102 in the vicinity of its head. The mould 1102 forms a recess 1102 in the vicinity of the head of the anchor 1106. As shown in Figs. 11A and 11B, the sixth alternate embodiment does not necessarily have an aperture adjacent to the foot. The anchor according to the invention has at least one cut-out recess through the foot, and preferably has two cutout recesses 1108A and 1108B formed in the foot.

The mould 1102 is rotated in the direction indicated by arrow 1120. This produces centripetal forces and cause the concrete to flow in the direction indicated by arrows 1110 and 1114. The cut-out recesses 1108A and 1108B in the foot of the S anchor 1106 significantly improved the compaction of the concrete in the shadow of the foot of the anchor 1106 in the vicinity of the anchor shafi thereby overcoming a S. disadvantage of the prior art. As shown in Fig. 10A, the deleterious effect of the foot of the conventional anchor is greatest in the lee of the anchor. Thus, an interrupted foot such as that of the fourth and fifth alternate embodiments, for example, greatly reduces or eliminates the disadvantage of the prior art by having the recess 36 of the anchlor 30 (Fig. for example, positioned leewardly to improve compaction in the vicinity of the shaft 32.

In the preferred and the alternate embodiments, the anchor comprises forged steel. Ilowever, it would be apparent to a person skilled in the art that the anchor can IN t ic 100438 (OC SV' he fabricated from any material, including other metals, that has sufficient tensile strength for use in this application without departing from the scope of the invention.

Furthermore, it is to be understood that the words which have been used are words of description, rather than limitation and that changes can be made without departing from the scope and spirit of the invention as defined in the claims.

a* IN 'lircI00438.DOC SDB

Claims (14)

1. An anchoring apparatus for lifting a rigid body of material, wherein aid apparatus is embedded in said body, said apparatus comprising: a shank; attachment means at one end of said shank for use to grasp said anchoring apparatus; and a foot at the other end of said shank, wherein a dimension of said foot transverse to the longitudinal axis of said shank is greater than the corresponding dimension of said shank, said foot formed to have one or more cut-out recesses through said foot for receiving a reinforcement means, wherein said shank incorporates an aperture adjacent to the other end of said shank for further receiving said reinforcing means, and firther wherein said shank, said attachment means and said fc integrally formed as said apparatus. 15

2. The anchoring apparatus according to claim 1 wherein said one or more recesses each define one or more surfaces substantially parallel to the longitudinal axis of said shank for receiving and engaging said reinforcement means.

3. The anchoring apparatus according to claim 2, wherein said one or more recesses are shaped to substantially enclose a section of said reinforcing means.

4. The anchoring apparatus according to either of claims 2 or 3, wherein said reinforcing means is made of a rigid material capable of being deformed to rigidly fit substantially in said one or more recesses for rigid engagement with corresponding surfaces of said one or more recesses.

5. The anchoring apparatus according to any one of claims 2 to 4, wherein a portion of said reinforcing means is crimped for engagement in said one or more recesses.

6. The anchoring apparatus according to any one of claims I to wherein said foot has two recesses through said foot forned on substantially opposite sides of said shank with respect to each other. IN 100438 DOC SDB TCW -12- 5 Sees *S S a. a..a S

7. The anchoring apparatus according to claim 1, wherein said reinforcement means is connected to said anchoring apparatus by engaging a looped section of said reinforcement means using said foot.

8. An anchoring apparatus for lifting a rigid body of material, wherein said apparatus is embedded in said body, said apparatus comprising: a shank; attachment means connected to one end of said shank for use to grasp said anchoring apparatus; and at least two laterally projecting elongated feet connected to the other end of 1 0o said shank and substantially forming a Tee-type structure for engaging a section of reinforcing means looped about said shank, wherein said shank, said attachment means, and said at least two feet are integrally formed as said apparatus.

9. The anchoring apparatus according to claim 8 wherein said laterally projecting feet are substantially fin-shaped protrusions.

10. The anchoring apparatus according to claim 8 wherein said laterally projecting feet each are formed to have a cross-sectional shape selected from the group consisting of a rectangular, circular, or square cross-sectional shape.

11. The anchoring apparatus according to anyone of claims 7 to wherein said looped section of said reinforcing means is formed by twisting said reinforcement means about said anchoring apparatus.

12. The anchoring apparatus according to any one of claims 1 to 11, wherein said reinforcement means comprises a metal bar.

13. The anchoring apparatus according to any one of claims I to 12, wherein said anchoring apparatus is made of metal.

14. The anchoring apparatus according to any one of claims 1 to 13, wherein said material is selected from the group consisting of concrete, plastic, or like castable substances. Anchoring apparatus for use within a rigid body of material substantially as described in the specification with reference to Figs. 1A-1C and 2A-2C, IN h~iC:100438 DOC SOB TCW or Fig. 3, or Fig. 4, or Figb. 5A-5C, 6A, 6B, 7A, and 7B, or Fig. 8, or Figs. 9A-9C of the accompanying drawings. DATED this Eighteenth Day of February 1999 Reid Construction Systems Pty Ltd Patent Attorneys for the Applicant SPRUSON FERGUSON MN V\[hc100430 DOC 600 TCW ABSTRACT AN ANCHORING APPARATUS FOR SOLID ELEMENTS An anchoring apparatus (10) is provided for use with a rigid body of material e.g, a concrete slab, wherein the anchoring apparatus is embedded in the body. The anchoring apparatus (10) comprises a shank (12) having an aperture (13) adjacent to one end for receiving reinforcing means A head (11) is connected to the other end of the shank (12) for grasping the anchoring apparatus The anchoring apparatus (10) further comprises a foot (15) connected to the shank which is characterised in that a dimension of the foot (15) corresponding to the shank (12) is greater than a transverse dimension of the shank Further, the foot incorporates one or more cut-out recesses (16) through the foot (15) for receiving and engaging the reinforcement means (23). o o f