Tapered, Locking, Anti-Reverse Coupler Assembly for Foundation Support System

This application is a continuation application of U.S. application Ser. No. 18/351,607 filed Jul. 13, 2023, which claims the benefit of U.S. Provisional Application Ser. No. 63/390,320 filed Jul. 19, 2022, the complete disclosures of which is hereby incorporated by reference in its entirety.

This application further relates in part to subject matter disclosed in U.S. application Ser. No. 17/174,805 filed Feb. 12, 2021, which claims the benefit of U.S. Provisional Application Ser. No. 62/976,442 filed Feb. 14, 2020, the entire disclosures of which are hereby incorporated by reference in their entirety.

The field of the invention relates generally to building foundation support systems including assemblies of coupled structural support shaft components, and more specifically to improved mechanical torque transmitting couplings for foundation support shaft components such as helical piers.

If a building foundation moves or settles in the course of construction, or at any time after construction is completed, such movement or settlement may affect the integrity of the building structure and lead to costly repairs. While much care is taken to construct stable foundations in new building projects, certain soil types or other building site conditions, or certain types of buildings or structures, may present particular concerns that call for additional measures to ensure the stability of building foundations.

Helical piers, also known as anchors, piles or screwpiles, are deep foundation solutions commonly used when standard foundation solutions are problematic. Helical piers are driven into the ground with reduced installation time and little soil disturbance compared to large excavation work that may otherwise be required by standard foundation techniques, and a number of helical piers may be installed at designated locations on a construction site to transfer and distribute the weight of the building structure to load bearing soil to prevent the foundation from moving or shifting. Lifting elements, support brackets or load-bearing caps may be used in combination with the helical piers to construct various types of foundation support systems meeting different needs for both foundation repair and new construction applications.

While known foundation support systems are satisfactory in many aspects, improvements are nonetheless desired.

In order to understand the inventive concepts described herein to their fullest extent, some discussion of the state of the art and certain problems and disadvantages that exist in the art is set forth below, followed by exemplary embodiments of improved foundation support systems and components therefore which overcome such problems and disadvantages in the art.

illustrates a perspective view of a conventional foundation support systemin combination with a building foundationwhich in turn supports a structure in a residential, commercial or industrial construction site. The structure being supported by the building foundationmay include various types of buildings, homes, edifices, etc. in real estate developments and improvements. The foundation support systemmay be applied in the new construction of the building foundationprior to the structure being completed, or may alternatively be applied for maintenance and repair purposes in a retrofit manner to a pre-existing building foundation at any desired time after the foundationand building structure are initially constructed. While exemplary structures are mentioned above, the foundation support systemmay be used in a similar manner to provide foundation support for various different types of structures and to securely support anticipated structural loads without more extensive excavation that standard building foundations otherwise require to provide a similar degree of support. The foundation support system described and illustrated herein is therefore a non-limiting example of the type of system that may be benefit from the inventive concepts described further below.

Primary piles or pipe shafts (hereinafter collectively referred to as a “pile” or “piles”)of appropriate size and dimension may be selected and may be driven into the ground or earth at a location proximate or near the foundationusing known methods and techniques. The size of the primary pileand the insertion depth needed to provide the desired support may be determined according to known engineering methodology and analysis of the construction site and the particular structure that is to be supported. The primary pilestypically consist of a long shaftthat is driven into the ground to the desired depth, and a support element such as a plate or bracket (not shown) or a lifting element such as a lifting assemblymay be assembled to the shaftproximate the foundation. The shaftof the primary pilemay also include one or more lateral projections such as a helical auger. Such helical steel pilesare available from, for example, Pier Tech Systems (www.piertech.com) of Chesterfield, Missouri.

The helical augermay in some embodiments be separately provided from the pilingand attached to the pilingby welding to a sleeveincluding the augerprovided as a modular element fitting. As such, the sleeveof the modular fitting may be slidably inserted over an end of the shaftof the piling shaftand secured into place with fasteners such as bolts as shown in. In such an embodiment, the sleeveincludes one or more pairs of fastener holes or openings for attachment to the piling shaftwith the fasteners shown. In the embodiment illustrated there are two pairs of fastener holes formed in the sleeve, which are aligned with corresponding fastener holes in the shaftto accept orthogonally-oriented fasteners and establish a cross-bolt connection between the shaftand the sleeve. To make a primary pilewith a particular length one merely slides the sleeveonto a piling shaftof the desired length and affixes the sleevein place. In the illustrated embodiment, the end of the piling shaftis provided with a beveled tipto better penetrate the ground during installation of the pile. In different embodiments, the tapered tipmay be provided on the shaftof the piling, or alternatively, the tipmay be a feature of the modular fitting including the sleeveand the auger.

The lifting assemblymay be attached to an upper end of the primary pileafter being driven into the ground. If the primary pileis not sufficiently long enough to be driven far enough into the ground to provide the necessary support to the foundation, one or more extension pilescan be added to the primary pileto extend its length in the assembly. The lifting assemblymay then be attached to one of the extension piles.

As shown in, the lifting assemblyinteracts with the foundationto support and lift the building foundation. In a contemplated embodiment, the lifting assemblymay include a bracket body, one or more bracket clampsand accompanying fasteners, a slider block, and one or more supporting boltswhich may be allthread rods, for example, and accompanying hardware. In another suitable embodiment the lifting assemblymay also include a jackand a jacking block. Suitable lifting assemblies may correspond to those available from Pier Tech Systems (www.piertech.com) of Chesterfield, Missouri, including for example only the TRU-LIFT® bracket of Pier Tech Systems, although other lifting assemblies, lift brackets, and lift components from other providers may likewise be utilized in other embodiments.

The bracket bodyin the example shown includes a generally flat lift plate, one or more optional gussets, and a generally cylindrical housing. The lift plateis inserted under and interacts with the foundation or other structurethat is to be lifted or supported. The lift plateincludes an opening, with which the cylindrical housingis aligned to accommodate one of the primary pileor an extension pile. The housingis generally perpendicular to the surface of lift plateand extends above and below the plane of lift plate.

In the example shown, one or more gussetsare attached to the bottom surface of the lift plateas well as to the lower portion of the housingto increase the holding strength of the lift plate. In one embodiment, the gussetsare attached to the housingby welding, although other secure means of attachment are encompassed within this invention.

In the example shown, the bracket clampsinclude a generally Ω-shaped piece having a center hole at the apex of the “Ω” to accommodate a fastener. The Ω-shaped bracket clampincludes ends, extending laterally, that include openings to accommodate fasteners. The fasteners extending through the openings in the endsare attached to the foundation, while the fastener extending through the center opening at the apex of the “Ω” extends into an opening in the housing. In one embodiment the fastener extending through the center opening in the bracket clampand into the housingfurther extends through one of the primary pileor the extension pileand into an opening on the opposite side of the housing, and then anchors into the foundation. In such cases, however, the fastener is not inserted through one of the primary pileor the extension pileuntil jacking or lifting has been completed, since bracket bodymust be able to move relative to pileorin order to effect lifting of the foundation.

In one embodiment, the bracket bodyis raised by tightening a pair of nutsattached to the top ends of the supporting bolts. The nutsmay be tightened simultaneously, or alternatively, in succession in small increments with each step, so that the tension on the boltsis kept roughly equal throughout the lifting process. In another suitable embodiment, the jackis used to lift the bracket body. In this embodiment, longer support boltsare provided and are configured to extend high enough above the slider blockto accommodate the jackresting on the slider block, the jacking block, and the nuts.

When all of the components are in place as shown and sufficiently tightened, the jack(of any type, although a hydraulic jack is preferred) is activated so as to lift the jacking plate. As the jacking plateis lifted, force is transferred from the jacking plateto the support boltsand in turn to the lift plateof the bracket body. When the foundationhas been lifted to the desired elevation, the nuts immediately above the slider block(which are raised along with support boltsduring jacking) are tightened down, with approximately equal tension placed on each nut. At this point, the jackcan then be lowered while the bracket bodywill be held at the correct elevation by the tightened nuts on the slider block. The jacking blockcan then be removed and reused. The extra support bolt material above the nuts at the slider blockcan be removed as well, using conventional cutting techniques.

The lifting assemblyand related methodology is not required in all implementations of the foundation support system. In certain installations, the foundationis desirably supported and held in place but not moved or lifted, and in such installations the lifting assembly shown and described may be replaced by a support plate, support bracket or other element known in the art to hold the foundationin place without lifting it first. Support plates, support brackets, support caps, and or other support components to hold a foundation in place are available from Pier Tech Systems (www.piertech.com) of Chesterfield, Missouri and other providers, any of which may be utilized in other embodiments of the foundation support system.

As mentioned, it is sometimes necessary to extend the length of a piling by connecting one or more shafts which in combination may provide support that extends deeper into the ground than the shafts individually can otherwise reach. For example, a first helical pier component, referred to as a primary pile, may be driven nearly fully into the ground at the desired location, and a connection component such as an extension pile may then be attached to the end of the primary pile in order to drive the primary pile deeper into the ground while supporting the building foundation at an end of the extension pile. More than one extension pile may be required depending on the lengths of the piles available and/or particular soil conditions.

are a side view and sectional view, respectively, of a coupler assembly that overcomes some of the drawbacks of prior couplers for foundation support systems such as that shown in. Specifically,illustrate a snap-lock coupler system in the form of couplers,that advantageously avoid any need for separately provided fasteners such as bolts to interconnect shafts associated with each respective coupler,. The couplerincludes a shaft receiving endfor a first shaft, and the couplerincludes a shaft receiving endfor a second shaft. The shafts associated with each coupler,may be, for example, primary piles and/or extension piles in the foundation support system. In lieu of bolts to maintain an engagement of the couplers,an annular spring elementis provided on the couplerthat automatically operates with snap-action engagement to axially interlock the couplers,to one another.

The coupleris formed with a main bodydefining a central passageway or bore having an inner surface with an inner diameter about equal to, but slightly larger than the outer diameter of a main bodyof the coupler. The couplerincludes a circumferential retaining grooveformed in its outer surface adjacent a distal end of the coupler, and the annular spring retainer elementextends in the retaining groove.

The main bodyof the coupleris formed with a number of outwardly projecting spaced apart and helically extending ribsthat are mated with complementary helical groovesformed on an inner surface of the main bodyof the coupler. As the couplers,are mated, the ribsdeflect the annular spring retainer elementto enlarge its diameter until the spring retainer elementresiliently snaps back to its original diameter. After snapping back to the original diameter, the spring retainer elementextends in a combination of the retaining grooveof the couplerand an aligned retaining groove formed in the coupler.

By virtue of the snap-action engagement of the couplers,the assembly of the couplers to make the desired interconnections of shafts is simplified, and issues associated with conventional separately provided fasteners such as bolts to make the desired interconnections of the shafts through the couplers is avoided. The spring retainer elementprovides an axial interlock of the engaged couplers,while the ribs and grooves simultaneously provide both axial and rotational interlock of the couplers,. Because the helical ribsand groovesdistribute any uplift forces in the mated outer and inner surfaces of the couplers,, the spring retainer elementmay be smaller and lighter than it otherwise may need to be if it exclusively bore all of the uplift forces that may be presented.

Further details of the snap-lock coupler system shown inare described in U.S. patent application Ser. No. 17/174,805, now published as U.S. Patent Application Publication No. 2021/0254298 of Pier Tech Systems, the teachings of which are incorporated by reference herein.

While the snap-lock couplers,solve significant problems presented in conventional foundation support systems and work well in certain installations, the present inventors have realized certain limitations presented in the snap-lock couplers for certain end-use installations. Specifically, the mated helical ribsand helical groovesin the couplers,were designed and intended to provide secure rotational interlock to transmit torque in either direction (forward or reverse) to drive a piling deeper into the ground or to partially or completely withdraw it from the ground, without requiring a separately fastener such as a bolt to complete the torque transmitting connection. While the inventors confirm that the mated helical ribsand helical groovesin the couplers,do provide secure rotational interlock to transmit torque in a forward direction as a helical pile is being driven into the ground, when the coupler assembly is subjected to reverse rotation a relative rotation of the couplers,is possible. That is, the expected rotational interlock of the couplers,in reverse rotation is not necessarily present, and relative reverse rotation of the couplers,with respect to one another may be problematic in some installations.

The inventors have observed an unexpected result in that the helical ribsexhibit a tendency to back out of the helical grooveswhen rotated in reverse. In other words, the helical ribsare prone to moving longitudinally in the helical groovesin a manner that the helical ribs, if not impeded, would axially withdrawal from the helical groovesand realize separation of the couplers when the coupler assembly is subject to reverse rotation. The spring retainer elementoperates to inhibit such withdrawal and associated separation of the couplers,and instead maintain the ribsfully engaged in the grooves. But this imposes an undesirable stress on the spring retainer elementthat can compromise the connection between the couplers,as reverse rotational force (i.e., torque) increases. In certain cases, torsional forces can rise to levels wherein the spring elementexperiences shear stress to the point of failure, leaving the couplers,effectively uncoupled in the axial direction. If uplift forces are also present in this state, the couplers,can undesirably separate from one another in a manner that would defeat the integrity of the foundation support system. Considering that this may happen at a below ground location that may be difficult to detect, the building foundation may not be adequately supported despite the presence of the foundation support system.

Additionally, and apart from any reverse rotation that tends to withdraw the helical ribsfrom the helical groovesand separate the couplers,, similar dynamics can result when the coupler assembly is subjected to uplift forces that tend to pull the couplers,apart. Initially the spring elementwill operate to oppose the uplift forces and maintain engagement of the ribsand grooves, but if uplift forces are sufficiently high, stress imposed on the spring elementmay cause it to shear and effectively uncouple the couplers with potential to defeat the integrity of the foundation support system.

are various views of a coupled shaft assemblyfor the foundation support systemshown inin accordance with an exemplary embodiment of the present invention that beneficially overcomes the limitations of the snap-lock coupler system shown in. Method aspects of the inventive couplers will be in part apparent and in part explicitly discussed in the following description.

The coupler assemblyin the example shown includes a first or outer couplerprovided on a first shaftwhich may be an extension pile in a foundation support system such as that shown in. The coupler assemblyalso includes a second or inner couplerprovided on a second shaftwhich may be a primary pile in a foundation support system such as that shown in. Alternatively the shafts,may each be extension piles in a foundation support system. It is recognized, however, the that shafts,need not be primary or extension foundation support pile elements at all, and instead the couplers,may be used in a wide variety of pipe or shaft systems that present similar problems and concerns to those discussed above or that may benefit from the coupling features described herein in another end use or application besides a foundation support system.

The couplers,including the features illustrated and described further below may be separately manufactured from the shafts,in certain embodiments, and thereafter attached to each shaft,in a known manner, including but not necessarily limited to welding. Alternatively, the couplers,may be integrally formed on respective ends of the shafts,via casting, forging and swaging processes instead of separately provided and attached elements. The couplers,and the shafts,may each be fabricated from high strength steel or another suitable material according to known techniques.

The shafts,connected through the couplers,can be hollow or filled with a substance such as concrete, chemical grout, or another known suitable cementitious material or substance familiar to those in the art to enhance the structural strength and capacity of the shafts when used as foundation support pilings or in other end use applications. The pilings defined by the connected shafts,may be prefilled with cementitious material in certain contemplated embodiments.

Likewise, in other contemplated embodiments, cementitious material, including but not necessarily limited to grout material familiar to those in the art, may be mixed into the soil around the piles as they are being driven into the ground, creating a column of cementitious material around the pilings for further structural strength and capacity to support a building foundation. Grout and cementitious material may be pumped through the hollow pilings under pressure as the pilings are advanced into the ground, causing the hollow pilings to fill with grout, some of which is released exterior to the pilings to mix with the soil at the installation site. Openings and the like can be formed in the piles to direct a flow of cementitious material through the piles and at selected locations into the surrounding soil.

Unlike the couplers shown in, there is no retainer spring elementin the coupled shaft assembly, and as such the potential issues associated with stressing and shearing of the spring elementare avoided in the coupled shaft assembly. A separately provided anti-reverse rotation elementin the form of a bolt extends through the couplersandto ensure that a problematic relative rotation and separation of the couplers,will not occur if the shaft, for example, is subjected to reverse rotation in the installation of a foundation support system and/or if the shaftis subjected to uplift forces in use. In the coupler assembly, and by virtue of the anti-reverse rotation element, rotational and uplift forces are borne between mating ribs and grooves formed in the couplers,as further described below.

As seen in the sectional views of, the outer couplerincludes a hollow main bodyand a shaft receiving end. The main bodyincludes an inner surfacehaving groovesdepending inwardly therefrom. Additionally, the main bodyis conical in shape for most of its axial length. The conical-shaped main bodyis axially tapered along an axial centerline of the main bodysuch that its diameter, and therefore its outer circumference also, gradually increases from the shaft receiving endtoward its open distal endopposite the shaft receiving end. In other words, the inner diameter of inner surfaceof the main bodyat the distal endis larger than the inner diameter of the inner surfaceof the main bodyadjacent the shaft receiving end, with the inner diameter uniformly decreasing from the endto the end. The outer circumference of the main bodyat the distal endis also larger than the outer circumference of the main bodyadjacent the shaft receiving end, with the outer circumference uniformly decreasing from the endto the end.

By comparison, the inner and outer diameters of the main body of the couplershown inis constant for most of its axial length and as such the main body of the coupleris not tapered or conical. The conical main bodyof the couplerhas a sidewall that is sloped relative to the axial centerline of the coupleras shown in, whereas the sidewall of the main body of the couplerinis not sloped and instead extends parallel to the axial centerline of the coupler.

The inner couplerincludes a hollow main bodyand a shaft receiving endin the illustrated example. The main bodyincludes an outer surfacehaving ribsprojecting outwardly therefrom. Additionally, the main bodyis conical in shape for most of its axial length. The main bodyis axially tapered such that its outer circumference gradually decreases from the shaft receiving endtoward its open distal endopposite the shaft receiving end. In other words, the outer diameter of outer surfaceof the main bodyat the distal endis smaller than the outer diameter of the outer surfaceof the main bodyadjacent the shaft receiving end, with the outer diameter uniformly decreasing from endto. The inner circumference of the main bodyat the distal endis likewise smaller than the inner circumference of the main bodyadjacent the shaft receiving end, with the inner circumference uniformly decreasing from endto.

By comparison, the inner and outer diameters of the couplershown inis constant for most of its axial length and is not tapered or conical. The conical main bodyof the couplerhas a sidewall that is sloped relative to the axial centerline of the coupleras shown in, whereas the sidewall of the main body of the couplerinis not sloped and instead extends parallel to the axial centerline of the coupler.

The anti-reverse rotation elementextends through and between a pair of openingsin the coupleras shown in. The openingsare elongated and oval-shaped and extend completely through the round sidewall of the main bodyof the coupler. The oval-shaped openingsfurther extend angularly as shown in. For the purposes herein, the angular extension of the openingsmeans that the openingsneither extend vertically nor horizontally in the sidewall of the conical main body. Since the main body has a round, tapered sidewall this means that the elongated openingstraverse a helical, spiral path of reducing diameter on the sidewall of the main bodyin the coupler. The elongated openingsconveniently avoid a need to precisely align the openingsrelative to the couplerto complete the desired interconnection as well as provide a limited freedom of movement of the anti-reverse rotation elementrelative to the elongated openingsin the coupler. The elongated openingsinstead define guide paths for relative movement of the anti-reverse rotation elementin the openingsand/or relative movement of the openingsrelative to the anti-reverse rotation element. Consequently, the couplerincluding the openingsmay move while the anti-reverse rotation elementremains stationary and vice versa.

As also seen in, the groovesin the couplerare also oversized relative to the ribsin the couplersuch that a gap is formed between one side of the ribsand the adjacent side of the grooves. Such oversizing of the grooves permits a limited degree of relative movement between the ribsand the grooveswhen the couplers,are mated to one another. Such limited freedom of movement, in turn, allows for limited, predetermined degree of relative rotation of the couplers,to more easily facilitate installation of the anti-reverse rotation element.

are various views of an exemplary embodiment of the inner coupler. The shaft receiving endis seen to have a first and larger outer diameter than the conical main body, and the distal endis also seen be inwardly tapered at a leading edge thereof to facilitate a self-guided engagement with the outer coupler. The conical main bodyextends between the shaft receiving endand the tapered leading edge of the distal end.

The conical main bodyis formed with a number of distinct, outwardly projecting spaced apart and helically extending ribsprojecting from outer surface. In the example shown, four helical ribsare provided that are spaced about 90° apart from one another on the conical main body. The helical ribseach extend spirally upon the outer surface of the main bodywith a relatively large pitch (i.e., the end-to-end vertical rise of the helical ribs inis large compared to the angular path of the helical ribs in the radial or circumferential direction). In the illustrated example, the pitch of the helical ribsis such that, from the base of the pile receiving endto the distal end of each rib, less than one complete turn of a helix is completed. For the context of the present description, a complete turn of a helix shall refer to a full 360° revolution on the circumference of the main body. As such, and in the exemplary coupler shown, each ribcompletes a fractional turn (i.e., less than one turn or less than a 360° revolution) of a helix on the main body.

In the illustrated example, each ribcompletes about a quarter turn (i.e., ¼ turn) of a helix on the main body, although more or less than about ¼ turn is possible in alternative embodiments. Because the main bodyis conical, the helix defined by each ribfurther has a reduced diameter from end to end of each rib. The distinct, helical ribsextend as thread-like members on the outer surface of the main body, but are specifically distinguished from a more conventional threaded connection including small pitch helical threads that continuously define multiple turns of a helix. While a specific geometry and a specific number of helical ribsis shown and described, it is appreciated that alternative numbers and/or alternative geometries of ribsis possible in another embodiment.

further show the pair of elongated helical openingsextending opposite one another in the main bodyand between adjacent helical ribs. The openingsare located at about 180° positions on the conical main bodyand as seen inare angled in different directions on each side of the main body. The openingsalso have a longitudinal length between the axial ends thereof that is less than a longitudinal length between the axial ends of the helical ribs.

are various views of the outer couplerincluding the shaft receiving end, the conical main bodyand the distal end. Helical groovesare formed to depend from the inner surfaceof the conical main body. Each helical groovereceives a respective one of the helical ribs() when the coupleris mated with the coupler(). The helical groovesare shaped in a complementary manner to the helical ribsbut are slightly larger than the helical ribs so as to permit a limited degree of side-to-side movement of the ribsin the groovesas described above.

The main bodyof the outer coupleralso includes a pair of openingsthat receive the anti-reverse rotation element. When installed, the anti-reverse rotation elementextends through and between a pair of openingsin the couplerand also through and between the openingsas shown in. Unlike the openingsthat are oval-shaped and extend as a helix, the openingsin the couplerare circular and sized to snugly fit the outer diameter of the anti-reverse rotation elementthat has a circular cross section. While the openingsdefine a guided path of movement for the anti-reverse rotation elementin use, the openingsin the couplerdo not. In other words, the openings, by design, are not elongated like the openingsand provide no path for relative movement between the anti-reverse rotation elementand the coupler. As a result, the couplerand the anti-reverse rotation elementcan move together but not separately. A reinforcing flangeof thicker material surrounds the openingsas shown to increase the structural strength around the openings.

The different shapes of the openingsandin combination of couplers,allows a limited degree of relative rotation of the couplersandin use, while providing a positive stop when the anti-reverse rotation elementreaches the upper end or lower end of the elongated openingsas best seen in. When the anti-reverse rotation elementreaches the upper end of the elongated openingsin the couplerany further relative rotation of the couplerwith respect to the coupleris precluded when the coupleris driven in the reverse direction. Likewise, and via the anti-reverse rotation elementand the elongated openings, when the anti-reverse rotation elementreaches the lower end of the elongated openingsany further relative rotation of the couplerwith respect to the coupleris precluded when the coupleris driven in the forward direction. The relative position of the anti-reverse rotation elementin the openingsand the relative positions of the ribsin the groovesmay change as the coupler assembly is driven in forward and reverse directions to drive a pile further into the ground or to withdraw it from the ground, but the couplersandat all times remain positively interlocked by the anti-reverse rotation element(which is fixed to the couplervia the openingsthat are not elongated) and as a result the couplersandwill not separate from one another. Additional rotation beyond the limited degree permitted by the elongated openingswould be required for the helical ribsto be withdrawn from the helical grooveswhen driven in the reverse direction but such additional rotation is not possible by the stops provided and the fixed connection of the anti-reverse rotation elementand the openings, and consequently the couplers,cannot be separated by reverse rotation or uplift force (either of which may be intentionally or unintentionally realized in the installation of the foundation support system. A structural integrity of the foundation support system is accordingly ensured in a manner that the couplers,may not ensure in certain installations on certain construction sites.

In contemplated embodiments the anti-reverse rotation elementmay be mechanically isolated in the assembly while the coupler assembly is subjected to forward and reverse rotation and/or uplift forces. In contemplated embodiments, rotational and uplift forces may be distributed solely through the ribsand groovesin the couplers while the anti-reverse rotation elementsecures the axial interlock only. In other embodiments, however, rotational torque transmission may be distributed between a combination of the ribs, grooves, and the anti-reverse rotation element. That is, the anti-reverse rotation elementneed not be mechanically isolated from torque transmission in certain contemplated embodiments.

Whether or not such mechanical isolation of the anti-reverse rotation elementis realized may depend on the relative locations of the elongated openingsand the stops provided relative to stops provided in the engagement of the ribs and grooves. In the exemplary embodiments depicted, for example, when the assembly() is driven in the forward direction, the distal ends of the ribs() in the couplermay be fully engaged to the complementary distal ends of the grooves() in the couplerbefore the anti-reverse rotation elementreaches the lower end of the elongated openingsin the coupler. In this arrangement, no forward torque is carried by the anti-reverse rotation element and the entirety of the forward torque transmission to drive the assemblyinto the ground is transmitted through the ribs and grooves.

In the reverse direction, torque would not be carried through the anti-reverse rotation elementwhen the anti-reverse rotation element has not completed the entire distance needed in the guide paths provided to reach the upper end of the elongated openingsin the coupler, or when another stop feature prevents the anti-reverse rotation elementfrom reaching the upper end of the elongate openings.

Because of such mechanical isolation of the anti-reverse rotation element, and because the force transmission in the forward direction would be greater in the forward direction than in the reverse direction, a single (i.e., only one) anti-reverse rotation elementis therefore sufficient in contemplated applications, and multiple anti-reverse rotation elementsare not required. A relatively simple and user friendly coupler assembly is therefore possible. In embodiments wherein the anti-reverse rotation elementmay not be mechanically isolated from torsional forces or uplift forces in the forward or reverse directions, additional anti-reverse rotation elementsare possible in alternative embodiments to more effectively distribute rotational forces through the assembly when needed. Of course, multiple anti-reverse rotation elementsmay be provided in various different embodiments that may or may not be individually mechanically isolated from torsional or uplift forces. Combinations of anti-reverse rotation elementsare likewise possible in the assemblywherein some of the anti-reverse rotation elementsare mechanically isolated while others are not mechanically isolated.