Apparatus for positioning clustered anchor bolt groups in concrete formwork

Abstract

An anchor-bolt positioning apparatus for positioning clustered anchor bolts in formwork for a concrete structure comprises a temporary scaffold deployable around the formwork, and an anchor bolt support frame mountable onto the temporary scaffold such that a prefabricated anchor bolt cluster supported by the anchor bolt support frame extends into the formwork. The anchor bolt support frame is laterally adjustable in a first direction relative to the scaffold, and bolt holders incorporated in the anchor bolt support frame that laterally retain the anchor bolt cluster are laterally adjustable in a second direction relative to the anchor bolt support frame, thus enabling precise and secure adjustment of the lateral position of the anchor bolt cluster prior to placement of concrete into the formwork. The apparatus may also include vertical adjustment means for levelling the anchor bolt support frame.

Description

[0001] APPARATUS FOR POSITIONING CLUSTERED ANCHOR BOLT GROUPS IN CONCRETE FORMWORK

[0002] FIELD OF THE DISCLOSURE

[0003] The present disclosure relates in general to apparatus for positioning anchor bolts in formwork for concrete foundations, and in particular for positioning clustered groups of anchor bolts in formwork.

[0004] BACKGROUND

[0005] It is commonly necessary to cast anchor bolts into concrete structures such as pile caps, equipment bases, and walls, for purposes of anchoring fixtures ranging from structural steel columns and heavy equipment for commercial and industrial buildings and other large structures, to wooden sill plates on residential foundation walls. Anchor bolts may be required to resist a variety of loads, such as uplift forces, out-of-plane lateral loads, and in-plane shear loads. In cases where anchor bolts by themselves would not provide the required load resistance, steel straps or plates or other appurtenances may need to be used in conjunction with the anchor bolts to transfer loads to the concrete structure.

[0006] Regardless of the specific purpose of the anchor bolts, it is always desirable and often critically important to ensure that the anchor bolts are held securely in position during construction, so that after the concrete has cured, the anchor bolts will be properly positioned and aligned to receive the fixtures they are intended to anchor. This entails positioning the anchor bolts accurately and securely in the formwork such that they are not susceptible to being knocked out of lateral position or angular alignment during placement of concrete in the formwork, and during related operations such as vibration of the freshly-placed concrete. Misplacement or misalignment of anchor bolts can result in the need for costly and time-consuming modifications to the concrete elements in which they have been cast and / or to the fixtures that they are intended to anchor.

[0007] There are many known methods and means for positioning anchor bolts in formwork. One simple and common method is to use anchor bolt templates made from dimension lumber (e.g., 2x6s, 2x8s, etc.) or plywood. In cases where multiple anchor bolts are required for anchoring a single fixture (such as the base plate for a structural column), the appropriate bolt pattern is marked out on the wooden template, and slightly oversize holes are drilled in the template to receive the anchor bolts. The bolts are then inserted into the holes in the templates, typically along with nuts and washers or other means to set the height that the bolts will project above the finished concrete. The assembly of the wooden template and anchor bolts is temporarily secured to the formwork, and concrete can then be placed in the formwork. In cases where individual anchor bolts are required at intermittent intervals, such as for anchoring a wooden sill plate to the top of a residential foundation wall (e.g., for supporting a wood-framed floor structure), the bolts can be positioned in holes in individual wooden templates temporarily secured to the wall forms.

[0008] These methods are satisfactory if carried out with proper care. Unfortunately, however, that often does not happen, and the result is anchor bolts that have been cast into the concrete in the wrong position in one or both lateral directions, and / or out of angular alignment, due to factors such as inaccurate marking and drilling of boltreceiving holes in the wooden templates, and inaccurate or insufficiently secure positioning of the templates on the formwork.

[0009] The difficulties associated with positioning anchor bolts, and the magnitude of the potential problems that can result from inaccurate positioning of anchor bolts, can be particularly challenging in the case of clustered groups of large and heavy anchor bolts for anchoring structures such as cell phone towers, large highway signs, electrical transmission towers, and wind turbine towers. Such structures commonly require a large number of large-diameter steel anchor bolts (commonly arrayed in a circular pattern) that can be several feet in length, and it can be particularly difficult and costly to rectify problems resulting from any one or more of such large and heavy anchor bolts in a clustered group having been cast into a concrete foundation element out of horizontal position and / or out of angular position. Accordingly, there is a need for methods and apparatus for accurately positioning large clustered anchor bolt groups in the formwork for a concrete foundation with greater reliability than provided by conventional anchor bolt setting methods.

[0010] Figures 1-3 in U.S. Patent No. 9,404,277 (Ozum) illustrate a prior art for holding anchor bolts in desired lateral positions and angular alignments while being cast into a concrete foundation. This prior art bolt-positioning apparatus (designated by reference number 100 in US 9,404,277) comprises three primary components:

[0011] • an elongate main body defining a longitudinal slot bounded by elongate side members;

[0012] • at least one bolt-holding element (“bolt holder”) slidably disposable within the longitudinal slot in the main body (“main body slot”) and adapted to receive an anchor bolt (typically by providing a hole extending through the bolt holder); and

[0013] • one or more abutment elements slidably disposable within the main body slot.

[0014] The bolt holders and abutment elements typically include stop means for setting the vertical positions of these components relative to the main body (and preventing them from falling through the main body slot).

[0015] To use this prior art bolt-positioning apparatus, the main body is positioned on the formwork for the pile cap or other foundation element into which anchor bolts are to be cast, with the slidable abutment elements positioned outboard of and on opposite sides of the formwork. One or more bolt holders are positioned in the main body slot, and an anchor bolt is installed in each bolt holder (either before or after the main body has been positioned on the formwork). The anchor bolts may be conveniently retained in their respective bolt holders by means of nuts installed on the threaded portions of the bolts extending above the bolt holders (or by any other suitable means).

[0016] After the main body of the prior art bolt-positioning apparatus has been mounted on the formwork in a desired position in a direction transverse to its longitudinal slot, the main body may be fixed in this position relative to the formwork by sliding each of the abutment elements up against the formwork and fixing the abutments to the formwork. The flanges (or other stop means) of the abutments can be nailed or stapled to the upper surface of the main body, at a suitable stage of the process, to fix the position of the main body in its longitudinal direction.

[0017] The bolt holder(s) may be slid within the main body slot to reach a desired longitudinal position relative to the formwork, and then fixed to the main body. At this stage, the bolt-positioning apparatus is fully assembled and securely mounted on the formwork, which is then ready to receive concrete.

[0018] The above-described sequencing of the steps in assembling and mounting the prior art bolt-positioning apparatus is by way of example only, and the required steps could be performed in different sequences to achieve desired results.

[0019] After the concrete wall or other foundation element has been cast and has sufficiently cured, the bolt-positioning apparatus can be removed by removing the nuts on the projecting anchor bolts, removing the nails, staples, or other fastening means used to fix the abutment elements to the formwork, and then lifting the apparatus off of the foundation.

[0020] BRIEF SUMMARY

[0021] The present disclosure teaches an anchor bolt positioning apparatus that uses one or more elongate bolt-positioning devices that are functionally-similar but modified versions of the bolt-positioning apparatus 100 shown in Figures 1-3 in US 9,404,277 to support a cluster of anchor bolts suspended in a formwork assembly during placement of concrete to construct a foundation element. The appropriate number of bolt-positioning devices for a given installation may vary according to the configuration of the particular anchor bolt cluster being installed. For exemplary purposes, however, the present disclosure describes and illustrates a typical (but non-limiting) embodiment that uses two bolt-positioning devices.

[0022] Rather than being supported on the formwork (as in the prior art assembly in US 9,404,277), the one or more bolt-positioning devices in accordance with the present disclosure are assembled into an anchor bolt support frame that is mountable on a temporary scaffold resting on the ground or other substrate such that the anchor bolt support frame spans over and clear of the formwork assembly, and such that the anchor bolt support frame is slidingly movable relative to the temporaiy scaffold to enable positional adjustment in the horizontal direction transverse to (as explained in greater detail further on in this document). Preferably (though not necessarily), the temporary scaffold may incorporate jack screws or other functionally suitable means enabling vertical adjustment of the anchor bolt support frame and the bolt-positioning devices incorporated into it.

[0023] The anchor bolt cluster to be cast into the foundation element is preferably preassembled with the lower regions of all bolts in the cluster being securely connected (such as, for example, by welding) to a lower bolt-spacing member, and with the upper ends of the bolts projecting through bolt holes in an upper bolt-spacing member and temporarily secured therein with nuts (preferably on each side of the upper bolt-spacing member). By way of non-limiting example, for a cluster of anchor bolts arrayed in a circular pattern, the upper and lower bolt-spacing members could be in the form of toroidal steel plates. Preassembly of the anchor bolt cluster in this manner facilitates precise and fixed positioning of all of the anchor bolts in the cluster relative to each other. However, embodiments in accordance with the present disclosure are not dependent on the anchor bolt cluster being assembled or fabricated in accordance with any particular method.

[0024] In a typical case, the anchor bolt support frame includes two bolt-positioning devices each comprising a pair of side rails slidingly insertable into a pair of side rail yokes so as to form a longitudinal slot between the two slide rails and between the two side rail yokes, with the longitudinal slot being for receiving sliding bolt holders. The anchor bolt support frame further includes transverse end members mountable to the ends of the pair of bolt-positioning devices to form the basic square or rectangular structure of the anchor bolt support frame, with the distance between the side rail yokes being adjustable by sliding one or both of the side rail yokes along the yoked side rail pairs. The temporary scaffold can be of any suitable structural configuration. In one exemplary and non-limiting embodiment, the temporary scaffold comprises four trussed frames that can be assembled to form a square or rectangular framework, with suitable base plates for supporting the scaffold on the ground or other support surface. A pair of girders are mounted onto and above two opposing side frames, preferably (but not necessarily) with vertical adjustment means (such as jack screws) being provided to enable height adjustment of the ends of the girders relative to the side frames in order to level the girders, such that the surface supporting the scaffold framework does not need to be perfectly level.

[0025] A pair of sliding support sleeves are slidingly mountable on each girder of the temporary scaffold, preferably in conjunction with friction-reducing means (such as, by way of non-limiting example, a Teflon® pad), with each sliding support sleeve being configured to receive and support one of the side rail yokes of the anchor bolt support frame. In one non-limiting embodiment, this functionality is provided by a vertical mounting post extending upward from an upper surface of each sliding support sleeve, with the vertical mounting post being receivable in a vertical bore provided in a side rail yoke of the anchor bolt support frame.

[0026] In preferred embodiments, the temporary scaffold is provided with transverse lateral adjustment means for adjusting the position of the anchor bolt support frame relative to the scaffold in a direction transverse to the side rails of the anchor bolt support frame. Such transverse lateral adjustment means may be provided in any functionally suitable form, such as (by way of non-limiting example) one or more horizontal jack screws mounted to the girders of the temporary scaffold.

[0027] To fully assemble an anchor bolt positioning apparatus in accordance with the present disclosure: the temporary scaffold may be positioned over the formwork for the foundation element in which the anchor bolt cluster is to be cast; • the anchor bolt support frame (or a subassembly thereof) may be assembled so as to be integrated with the preassembled anchor bolt cluster such that at least two anchor bolts pass through respective bolt holders slidably positioned in the longitudinal slots of each bolt-positioning devices, with side rail yokes slidingly installed on each pair of bolt positioning devices outboard of the slidable bolt holders;

[0028] • the integrated assembly of the anchor bolt support frame and the preassembled anchor bolt cluster may be hoisted (such as with the aid of lifting slings extending under and around the bolt-positioning devices) above the temporary scaffold, and then lowered onto and secured to the scaffold, with the anchor bolt cluster extending downward into the formwork.

[0029] Bi-directional lateral positioning of the anchor bolt cluster, as thus mounted to the temporary structural framework, may be enabled by adjustment means (such as, by way of non-limiting example, threaded rod or turnbuckle arrangements) acting between the bolt-positioning devices and the temporary structural framework and / or between the boltpositioning devices and the supported anchor bolt cluster. After the positioning of the anchor bolt cluster has been finally adjusted and confirmed to be correct, concrete can then be placed in the formwork.

[0030] After the concrete has sufficiently cured, the temporary nuts on the upper ends of the anchor bolts can be removed, thus allowing the upper bolt-spacing member to be removed. The lower bolt-spacing member becomes embedded in the concrete foundation element, as a matter of practical necessity, while also augmenting the pull-out resistance of the embedded anchor bolts. The temporary structural framework, the bolt-positioning devices, and the upper bolt-spacing member can be re-used.

[0031] The upper and lower bolt-spacing members are preferably designed with sufficient structural strength and flexural stiffness to prevent excessive vertical deflection of the portions of the bolt-spacing members that might be effectively cantilevering from the bolt-positioning device during installation of the integrated assembly of the anchor bolt support frame and the anchor bolt cluster and until the anchor bolt cluster has been embedded in concrete.

[0032] Installation of anchor bolts in the bolt holders may be facilitated by providing the bolt holders as two-component assemblies, allowing an anchor bolt to be moved laterally into a vertical recess in a first bolt holder component, and slidingly secured relative to the bolt holder by a second bolt holder component lockingly engageable with the first bolt holder component.

[0033] BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Embodiments in accordance with the present disclosure will now be described with reference to the accompanying Figures, in which numerical references denote like parts, and in which:

[0035] FIGURE 1 is a perspective view of the primary components of a a prior art bolt-positioning apparatus as illustrated in Figures 1-3 in U.S. Patent No. 9,404,277.

[0036] FIGURE 2 is a cutaway perspective view of the prior art bolt-positioning apparatus of FIG. 1 mounted on formwork for a concrete foundation element, with anchor bolts installed in the bolt holders of the apparatus.

[0037] FIGURE 3 is a non-cutaway perspective view of the prior art apparatus in FIG. 2.

[0038] FIGURE 4 is an isometric view of a representative example of a preassembled anchor bolt cluster that may be positioned in concrete formwork using in accordance with the present disclosure.

[0039] FIGURE 5 is an isometric view of an exemplary and non-limiting embodiment of a temporary scaffold in accordance with the present disclosure.

[0040] FIGURE 5A is an exploded partial view of the scaffold embodiment shown in FIG. 6. FIGURE 6 is an isometric partial view of an exemplary and non-limiting embodiment of an anchor bolt support frame in accordance with the present disclosure.

[0041] FIGURE 7 is a perspective view of an exemplary and non-limiting embodiment of a bolt holder assembly in accordance with the present disclosure.

[0042] FIGURE 8 is an exploded isometric detail illustrating the mounting of a girder of the temporary scaffold and the mounting of a side rail yoke of the anchor bolt support frame onto a sliding support sleeve mounted on a girder of the temporary scaffold.

[0043] FIGURE 8A is an isometric detail of a sliding support sleeve illustrating installation of friction-reducing element in the sliding support sleeve.

[0044] FIGURE 9 is a perspective view of an anchor bolt support frame generally as shown in FIG. 6 mounted on a temporary scaffold generally as shown in FIG. 5, but with no anchor bolt cluster shown.

[0045] FIGURE 10 is a partial-cutaway isometric view illustrating an exemplary and non-limiting method of integrating an anchor bolt support frame in accordance with the present disclosure into a prefabricated anchor bolt cluster.

[0046] FIGURE 11 is a perspective view of an anchor bolt support frame mounted on a temporary scaffold, generally as shown in FIG. 9, but with the anchor bolt support frame assembled so as to support an anchor bolt cluster.

[0047] FIGURE 12A, 12B, and 12B are isometric details of an embodiment of an anchor bolt (or rebar) guide device for positioning an anchor bolt or a reinforcing steel bar in concrete formwork. DETAILED DESCRIPTION

[0048] Prior Art Bolt-Positioning Apparatus

[0049] FIGS. 1-3 illustrate an exemplary installation of a pair of prior art bolt-positioning devices 100 in the formwork for a concrete structure, with each bolt-positioning device having the following main components:

[0050] • an elongate main body 10 having a longitudinal slot 15;

[0051] • one or more bolt-holding elements (“bolt holders”) 20, each being slidably disposable within slot 15 of main body 10, and having: o a lower section 24; o bolt holder fastening means, for facilitating fastening of bolt holder 20 to main body 10, provided in the illustrated example as a tab or flange 22 projecting laterally from an upper region of lower section 24; and o a typically vertical bolt-receiving hole 25 extending through lower section 24 of each bolt holder 20; and

[0052] • two abutment elements 30, each comprising: o a middle section 38, configured to be slidably disposable within slot 15 of main body 10; o abutment fastening means, for facilitating fastening of abutment 30 to main body 10, provided in the illustrated example as a tab or flange 32 projecting laterally from an upper region of middle section 38; and o a lower section 36 extending downward from middle section 38, and optionally having one or more lateral projections 34 (for preventing vertical displacement of abutment 30 relative to main body 10 after being installed in slot 15).

[0053] FIGS. 2 and 3 illustrate a pair of prior art bolt-positioning devices 100 mounted on a formwork assembly 50, with anchor bolts 40 positioned in bolt holders 20. FIG. 3 shows the apparatus after bolt holders 20 (and bolts 40) have been laterally positioned as desired relative to the fully-assembled formwork 50, with lower sections 36 of abutments 30 positioned against formwork 50, and with flange 22 of each bolt holder 20 and flange 32 of each abutment 30 fastened to the associated main body 10, and with lower section 36 of each abutment fastened to formwork 50 (by fasteners indicated by reference character F in FIG. 3).

[0054] Apparatus For Positioning Clustered Anchor Bolts

[0055] FIG. 4 illustrates a representative and non-limiting example of a prefabricated anchor bolt cluster 150 that may be positioned in concrete formwork using an anchor bolt positioning apparatus in accordance with the present disclosure. In the illustrated example, anchor bolt cluster 150 comprises a plurality of elongate anchor bolts 140 connected at their lower ends to a lower bolt-spacing member 154 (such as by welding), and with at least an upper region of each anchor bolt 140 being threaded as indicated by reference number 141. The upper ends of anchor bolts 140 are retained by an upper boltspacing member 152 by means of upper nuts 142 and lower nuts 143. Anchor bolts 140 are illustrated as being arrayed in a circular pattern, but this by way of example only, as there is virtually no limit to the configurations of anchor bolt clusters that could be positioned using anchor bolt positioning apparatus in accordance with the present disclosure.

[0056] FIGS. 5 and 5A illustrate an embodiment 200 of a temporary scaffold structure in accordance with the present disclosure. In the illustrated embodiment, temporary scaffold 200 comprises a first pair of opposing side frames 210 and a second pair of opposing side frames 220 that can be assembled to form a square or rectangular structure. This configuration is by way of illustrative and non-limiting example, as temporary scaffold structures of different polygonal or even curvilinear configurations could be devised without departing from the scope of the present disclosure.

[0057] The first pair of opposing side frames 210 and the second pair of opposing side frames 220 are shown as being connected to corner posts 212 having base plates or bearing pads 216 for supporting temporary scaffold 200 on the ground or other supporting surface. Preferably but not essentially, upper ends 214 of one or more comer posts 212 may incorporate vertical adjustment means 215, which is illustrated as being provided by girder support bracket 216 each having a downward-extending jack screw 218 insertable into upper end 214 of a comer post 212, with a nut on jack screw 218 to enable manual adjustment of the height of bracket 216. However, this is by way of nonlimiting example only, as alternative forms of vertical adjustment means may be devised in accordance with known technologies without departing from the scope of the present disclosure.

[0058] A girder 230 is shown extending between and connected to the girder support brackets 216 at the ends of each of opposing side frames 220, a pair of abutments , with a pair of sliding support sleeves 240 being slidingly installed on each girder 230 between a pair of abutments 250 mounted to an upper surface of girder 230, for mounting (and reacting forces from) a first horizontal adjustment means 252 (shown by way of nonlimiting example as being provided in the form of simple horizontal jack screws comprising threaded rods with associated adjustment nuts), for adjusting the horizontal position of an anchor bolt support frame mounted on temporary scaffold 200, in a direction parallel to girders 230.

[0059] Sliding support sleeve 240 is illustrated in FIGS. 5, 5A, 8, and 8A as being (by way of non-limiting example) a rectangular tubing element having a rectangular channel 244 for receiving girder 230 (also shown by way of non-limiting example as a rectangular tubing element), preferably in conjunction with a friction reduction element 246 (such as a Teflon® paid) disposed between the upper surface of girder 230 and the “roof’ of channel 244. A vertical mounting post 242 extends upward from an upper surface of sliding support sleeve 240 for receiving a side rail yoke of an anchor bolt support frame in accordance with the present disclosure (as described later herein).

[0060] As will be appreciated from FIGS. 5 and 5A, temporary scaffold structure 200 may be (but not necessarily must be) capable of disassembly into its component parts for storage and / or shipping purposes, but it may also be transported between job sites in its fully-assembled form, depending on project-specific requirements and constraints. FIG. 6 illustrates an exemplary and non-limiting embodiment 300 of an anchor bolt support frame in accordance with the present disclosure. In the illustrated embodiment, anchor bolt support frame 300 comprises a pair of bolt-positioning devices 305 each comprising a pair of side rails 310 slidingly insertable into a pair of side rail yokes 360 so as to form a longitudinal slot 315 between slide rails 310, bounded longitudinally by the two side rail yokes 360, with longitudinal slot 315 being for receiving sliding bolt holders 320. Anchor bolt support frame 300 further includes transverse end members 340 mountable to the ends of the pair of bolt-positioning devices 310 to form the basic square or rectangular structure of the illustrated embodiment of anchor bolt support frame 300, with the distance between the two side rail yokes 360 on each bolt-positioning device 305 being adjustable by sliding one or both side rail yokes 360 sleeves along the yoked pair of side rails 310.

[0061] Preferably, a second horizontal adjustment means 352 is provided on each transverse end member 340 to adjust the position of anchor bolts suspended from anchor bolt support frame 300 in a direction parallel to longitudinal slots 315 in bolt-positioning devices 305. In the exemplary embodiment shown in FIG. 6, second horizontal adjustment means 352 is provided in the simple form of jack screws comprising threaded rods passing through transverse end member 340 with associated adjustment nuts, and with a first variant 352A of an anchor bolt engagement element associated with each threaded rod, for contacting one or more anchor bolts 140 of an anchor bolt cluster 150 supported by bolt support frame 300, and consequently urging horizontal displacement of anchor bolt cluster 150 relative to bolt support frame 300 in response to horizontal forces induced by actuation of second horizontal adjustment means 352, with such induced forces causing longitudinal sliding displacement of bolt holders 320 within longitudinal slots 315 of bolt-positioning devices 305.

[0062] Anchor bolt support frame 300 may need to be provided as a set of separate components in order to be assembled and “integrated” with a prefabricated anchor bolt cluster, as illustrated in FIGS. 10 and 11. Accordingly, FIG. 6 illustrates connection plates 350 for demountable connecting transverse end members 340 to the ends of bolt- positioning devices 305. In variant embodiments, however, it may be possible to provide anchor bolt support frame 300 as an assembled frame or subframe in cases where it is necessary or desired to mount the required anchor bolts in anchor bolt support frame 300 individually rather than as a prefabricated anchor bolt cluster.

[0063] FIG. 7 illustrates one non-limiting embodiment 320 of a U-shaped bolt holder slidingly disposable within longitudinal slots 315 of bolt-positioning devices 305. Bolt holder 320 has two channels 321 through which the side rails 310 of a bolt-positioning device 305 can be slidingly inserted, plus a central recess 325, between channels 321, contoured to receive an anchor bolt 140 within a vertical semi-cylindrical medial region of central recess 325 formed in bolt holder 320. Central recess 325 also defines vertical keyways 322 and horizontal ledges 323 for receiving, respectively, vertical keys 332 and horizontal flanges 333 formed on an anchor bolt retainer plug 330 that can be vertically inserted into central recess 325 of bolt holder 320 after an anchor bolt has been disposed within central recess 325. A vertical cylindrical channel is thus formed by the semi- cylindrical medial region of central recess 325 and a vertical semi-cylindrical recess 335 on an inner side of retainer plug 330, enclosing a perimeter region of the anchor bolt and preventing later displacement relative to bolt holder 320.

[0064] FIG. 8 illustrates an embodiment of a side rail yoke 360 having a pair of side rail channels 364 for slidingly receiving the side rails 310 of a bolt-positioning device 305 of bolt support frame 300. Each side rail yoke 360 has a vertical hole 362 whereby side rail yoke 360 can be mounted onto a sliding support sleeve 240 of temporary scaffold 200, with mounting post 242 on sliding support sleeve 240 inserted into vertical hole 362 in side rail yoke 360.

[0065] FIG. 9 illustrates a non-limiting embodiment of a fully-assembled anchor bolt positioning apparatus in accordance with the present disclosure, with an anchor bolt support frame 300, generally as shown in FIG. 6, mounted onto a temporary scaffold 200, generally as shown in FIGS. 5 and 5A, as the apparatus would appear if assembled without any anchor bolts being support by anchor bolt support frame 300. In this illustrated embodiment, a variant embodiment 352B of an anchor bolt engagement element is provided in association with second horizontal adjustment means 352 of anchor bolt support frame 300, comprising a clevis-type device connected to a jack screw arrangement (as previously described) for mounting around an anchor bolt to enable bidirectional displacement of a supported anchor bolt cluster 150 according to the direction in which the jack screw is rotated.

[0066] FIG. 10 illustrates an exemplary method of assembling an anchor bolt support frame 300 so as to be “integrated” with a prefabricated anchor bolt cluster 150 I, and thus to facilitate positioning of anchor bolt cluster 150 within formwork for a corresponding concrete structure. In the illustrated example, two bolt-positioning devices 305 are assembled around a selected pair of anchor bolts 140, with side rail yokes 360 installed over (and temporarily secured to) the ends of the pair of side rails 310 of each boltpositioning device 305 and thus forming longitudinal slots 315 in each bolt-positioning device 305, enabling installation of bolt holders 320 within slots 315 to support the selected anchor bolts.

[0067] Transverse end members 340 (not shown in FIG. 10) could be fastened to the ends of the two bolt-positioning device 305 (as seen in FIG. 6) at this stage, but that step is not essential at this stage and can be deferred until after anchor bolt support frame 300, carrying anchor bolt cluster 150, has been mounted onto temporary scaffold 200. That step can be carried out by (for example) installing lifting slings (not shown) under the two bolt-positioning devices 305 of the partially-assembled anchor bolt support frame 300, whereby a crane can engage the slings to raise the two bolt-positioning devices 305 until they engage upper bolt-spacing member 152 of anchor bolt cluster 150 (or, more specifically in the illustrated embodiment, until they engage lower nuts 143 on threaded upper regions 141 of the selected anchor bolts 140), at which point further lifting force from the crane will lift the “integrated” assembly of the two bolt-positioning device 305 and anchor bolt cluster 150, so that this assembly can then be mounted onto temporary scaffold 200. The remaining components of scaffold 200 and anchor bolt support frame 300 can be installed (and adjusted as appropriate), with the anchor bolt positioning apparatus then being fully assembled as illustrated in FIG. 11, with anchor bolt cluster 150 extending downward into formwork (represented by reference number 175) for the concrete foundation element being constructed.

[0068] FIGS. 12A, 12B, and 12C illustrate an embodiment 400 of a generally U-shaped anchor bolt (or rebar) guide device in accordance with the present disclosure that can be conveniently used to accurately position an anchor bolt or a projecting steel reinforcing bar within formwork 450 for a concrete wall or other concrete structure. Guide device 400 has a central recess 404 defining a vertical semi-cylindrical medial region, and two channels 402 passing through the portions of the device on each side of central recess 404 in a directed transverse to central recess 404. Channels 402 are configured such that when an anchor bolt (or rebar) 420 is disposed within the semi-cylindrical medial region of central recess 404 (as seen in FIG. 12B), a retaining member 410 (such as a “2x4” or other wooden member) can be passed through both channels 402 so as to retain anchor bolt (or rebar) 420 within central recess 404 (as seen in FIG. 12C). To fix the lateral position of anchor bolt (or rebar) 420 relative to formwork 450, nails or other fasteners can be driven or inserted through fastener holes 405 to secure guide device 405 to retaining member 410, which in turn can be nailed or otherwise fastened to formwork 450.

[0069] Although anchor bolt (or rebar) guide device 400 is illustrated being used in the construction of a comparatively light structure such as a conventional concrete wall, the general structural configuration and operative principles of this device may be adapted for purposes of alternative embodiments of bolt holders 320 for use in anchor bolt positioning apparatus as previously described herein, and such alternative embodiments are intended to come within the scope of the present disclosure.

[0070] # # # # #

[0071] It will be readily appreciated by persons skilled in the art that various modifications to embodiments in accordance with the present disclosure may be devised without departing from the scope of the present teachings, including modifications that use equivalent structures or materials hereafter conceived or developed. It is especially to be understood that the scope of the present disclosure is not intended to be limited to described or illustrated embodiments, and that the substitution of a variant of any claimed or illustrated element or feature, without any substantial resultant change in functionality, will not constitute a departure from the scope of the disclosure.

[0072] In this patent document, any form of the word “comprise” is to be understood in its non-limiting sense to mean that any element or feature following such word is included, but elements or features not specifically mentioned are not excluded. A reference to an element or feature by the indefinite article "a" does not exclude the possibility that more than one such element or feature is present, unless the context clearly requires that there be one and only one such element or feature.

[0073] Any use herein of any form of the terms “affix”, “connect”, “mount”, or any other term describing an interaction between elements is not intended to limit the interaction to direct interaction between the subject elements, and may also include indirect interaction between the elements such as through secondary or intermediary structure

[0074] Wherever used in this document, the terms “typical” and “typically” are to be understood and interpreted in the sense of being representative of common usage or practice, and are not intended to be understood or interpreted as implying essentiality or invariability.

Claims

WHAT IS CLAIMED IS:

1. An apparatus for positioning clustered anchor bolts within a formwork assembly, said apparatus comprising a temporary scaffold and an anchor bolt support frame, wherein:(a) the scaffold comprises a plurality of side frames forming a polygonal structure, including two opposing and parallel side frames each supporting a girder parallel to the side frames, with two sliding support sleeves slidingly mounted on each girder;(b) the anchor bolt support frame mountable onto the scaffold and comprising:• a pair of bolt-positioning devices each comprising a pair of side rails slidingly insertable into a pair of side rail yokes so as to form a longitudinal slot between the slide rails, said side rail yokes being configured for mounting on respective sliding support sleeves of the scaffold, and said longitudinal slot being configured to receive one of more sliding bolt holders; and• transverse end members mountable to the ends of the pair of boltpositioning devices;(c) the scaffold includes a first horizontal adjustment means, for adjusting the horizontal position of the anchor bolt support frame relative to relative to the scaffold in a direction parallel to the girders; and(d) the anchor bolt support frame includes a second horizontal adjustment means, for adjusting the position of an anchor bolt cluster supported by the anchor bolt support frame by means of the bolt holders, in a direction parallel to the longitudinal slots in the bolt-positioning devices.

2. The apparatus as in Claim 1 wherein one or both of the first and second horizontal adjustment means comprises jack screws.

3. The apparatus as in Claim 1 or Claim 2, further comprising vertical adjustment means for levelling the anchor bolt support frame.

4. The apparatus as in Claim 3 wherein the vertical adjustment means comprises jack screws.

5. The apparatus as in any one of Claims 1-4 wherein the anchor bolt support frame is mountable to the scaffold by means of vertical posts provided on the sliding support sleeves of the scaffold, said posts being insertable into corresponding vertical holes in the side rail yokes of the anchor bolt support frame.

6. The apparatus as in any one of Claims 1-5 wherein the anchor bolt support frame is provided in disassembled form enabling the anchor bolt support frame to be at least partially assembled to be integrated with an anchor bolt cluster provided as a prefabricated anchor bolt cluster.

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