SPOIL-LOCKING COUPLER SYSTEM

Description

RELATED APPLICATIONS

This application claims priority to Australian Provisional Patent Application No. 2024903527 the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to screw pile and blade pile systems. In particular, although not exclusively, the invention relates to a coupling system for effective connection of a drive head to a blade pile main shaft.

BACKGROUND

Screw piles and blade piles are commonly used in the construction of buildings, solar farms and other structures. A typical screw/blade pile comprises a shaft, normally made from mild steel or a higher strength steel. A helical screw or blade is attached to the shaft. In order to insert the screw pile into the ground, the screw pile is rotated and pressed downwardly, which causes the helix or blade to bite into and screw into the ground. Once the pile has been properly installed in the ground, a weight supported by the pile is distributed from the helical screw or blade into the earth that lies underneath and adjacent the screw/blade pile. Further, the overburden pressure of the earth positioned above the screw/blade assists in resisting any lifting forces applied to the pile and thereby assists in maintaining the pile in the ground.

Conventional screw/blade piles comprise a single helical screw or a pair of blades. The helical screw has a single leading edge that moves through and breaks the earth as the pile is screwed into the ground. Blade piles typically have two leading edges on the blades, which extend generally perpendicularly to the outer periphery of the blades (when viewed from above). As the shaft is normally cylindrical in shape, the leading edges of the blades may be considered to extend outwardly from the shaft in the radial direction.

Australian patent application number 2010202047 and Australian innovation patent number 2011100820, the entire contents of which are herein incorporated by reference, describe a screw pile comprising a shaft, at least two blades extending outwardly from the shaft, each blade having a leading edge that contacts earth as the screw pile is screwed into the ground, the leading edges including at least a portion extending in a direction that is non-perpendicular to an outer periphery of the shaft (when viewed from above).

Large-scale solar energy installations typically comprise a number of solar photovoltaic cells or solar collectors (such as solar collectors that are used to heat water to produce steam). In some solar energy installations, the solar photovoltaic cells or solar collectors track the sun during the day in order to maximise the amount of solar energy collected. To enable such tracking, some installations mount a number of solar photovoltaic cells or solar collectors to large drive beams, and the drive beams are slowly rotated during the day to track the movement of the sun. The drive beams and associated structure must be firmly mounted in the ground in a number of locations in order to firmly support the drive beam and stop or minimise distortion of the drive beam during use. Thus, many large-scale solar energy installations mount the supporting structure for the drive beams to concrete or driven steel beam foundations.

However, compared to such concrete or driven steel beam foundations, screw/blade piles often can be more effective and more economical as drive beam foundations. And to enable wider and more efficient applications of screw/blade pile technology, there remains a need for lighter, stronger and/or less expensive screw/blade pile designs.

For example, some blade pile designs include numerous expensive welding and machining operations to manufacture a new drive head that is separately coupled to a main shaft. Existing alternatives to such welded drive heads include integral forged drive heads; however, such forged drive heads generally are very heavy due to the large amounts of steel (and thus added cost) needed to withstand the high torque and bending forces applied to the drive head body and blades during installation in often rocky or hard soils. Further, coupling elements such as bolts or screws for coupling a blade pile drive head to a blade pile main shaft can also add significant costs. Large solar panel farms can require hundreds of thousands of individual blade piles, and thus even minor cost and material savings per pile can be very beneficial.

Also, robust and reliable coupling of a blade pile drive head to a separate blade pile main shaft can be important to enable effective installation, operation, and removal of a blade pile. The ability to efficiently remove solar panel farm installations, including supporting blade piles, sometimes many years or even decades after installation, can be important for environmental site remediation.

Therefore, there is a need for further improved blade pile designs, including improved coupling mechanisms for coupling a blade pile drive head to a main shaft.

OBJECT OF THE INVENTION

It is an object of the present invention to overcome and/or alleviate one or more of the disadvantages of the prior art or provide the consumer with a useful or commercial choice.

SUMMARY OF THE INVENTION

In one aspect, although it need not be the only or the broadest aspect, the invention resides in a spoil-locking coupler system, comprising:

• • a drive element, comprising:
    • a body having a hollow portion with an internal wall and an external wall, the hollow portion defining a socket with a longitudinal axis;
    • a spoil diversion blade extending outward from the external wall;
    • an opening in the hollow body between the internal wall and the external wall and adjacent to the spoil diversion blade; and
    • a first tab-in-groove locking element positioned on the internal wall adjacent the opening; and
  • a coupled shaft having an outer surface that defines a second tab-in-groove locking element connectable to the first tab-in-groove locking element;
  • wherein the coupled shaft is connected to the body of the drive element during powered rotation of the system about the longitudinal axis and into a medium; and
  • wherein the spoil diversion blade is operable to guide spoil from the medium through the opening in the hollow body and into a groove of the first or second tab-in-groove locking element, thereby locking the coupled shaft to the drive element.

Optionally, the first tab-in-groove locking element comprises a tab protruding from the internal wall of the hollow body, and the second tab-in-groove locking element comprises the groove, wherein the groove is defined on the outer surface of the coupled shaft.

Optionally, the spoil diversion blade comprises a cutting edge that is angled away from the longitudinal axis so that it is normal to a direction of advance of the cutting edge through the medium.

Optionally, the groove is fabricated by pressing into the outer surface of the coupled shaft.

Optionally, the coupled shaft comprises a hollow tube.

Optionally, the drive element comprises a drive head of a screw pile and the coupled shaft comprises a hollow main shaft of the screw pile.

Optionally, the drive head further comprises at least one blade extending away from the longitudinal axis.

Optionally, a distal end of the body opposite the socket defines an attack bit.

Optionally, the body and at least one blade are cast as a single integral part.

Optionally, the at least one blade comprises a leading bevelled edge for cutting into ground below the drive head during installation of a corresponding blade pile, and a reversing bevelled edge for cutting into ground above the drive head during removal of a corresponding blade pile.

Optionally, the at least one blade comprises a pair of blades.

Optionally, a thickness of the at least one blade reduces progressively outward from a base of the blade to a curved centroid line near a centre of the blade.

Optionally, a base of the at least one blade includes an angled radius to ensure a robust attachment of the blade to the body and, in use, to deflect and flow spoil around the drive head.

Optionally, a top end of the hollow body is keyed and angled outward to guide and receive a distal end of the coupled shaft.

Optionally, the coupled shaft is a cylindrical main shaft of a blade pile.

Optionally, during installation of the screw pile a drive shaft extends through the main shaft and engages the socket of the drive head, whereby powered rotation of the drive shaft rotates the drive head and the main shaft.

Optionally, the second tab-in-groove locking element comprises longitudinal and transverse grooves pressed into the outer surface of the hollow main shaft.

BRIEF SUMMARY OF THE DRAWINGS

To assist in understanding the invention and to enable a person skilled in the art to put the invention into practical effect, preferred embodiments of the invention are described below by way of example only with reference to the accompanying drawings, in which:

FIG. 1 is a top perspective view of a blade pile drive head, according to an embodiment of the present invention.

FIG. 2 is a bottom perspective view of the blade pile drive head of FIG. 1.

FIG. 3 is a side perspective view of a main shaft of a pile, according to some embodiments of the present invention.

FIG. 4 is a side perspective view of an assembled pile, including the blade pile drive head of FIG. 1 and the main shaft of FIG. 3, according to some embodiments of the present invention.

FIG. 5 is a further top perspective view of the blade pile drive head of FIG. 1, showing hexagonal sides of a socket.

FIG. 6 is a top view of the blade pile drive head of FIG. 1, further illustrating the relative concentric positioning of its elements.

FIG. 7 is a side cross-sectional view of the drive head of FIG. 1, showing the upper and lower spacing between two tabs.

FIG. 8 is a cross-sectional view through section B-B that is shown in FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention relates to a spoil-locking coupler system. Elements of the invention are illustrated in concise outline form in the drawings, showing only those specific details that are necessary to understanding the embodiments of the present invention, but so as not to clutter the disclosure with excessive detail that will be obvious to those of ordinary skill in the art in light of the present description.

In this patent specification, adjectives such as first and second, left and right, above and below, top and bottom, upper and lower, front and back, etc., are used solely to define one element or method step from another element or method step without necessarily requiring a specific relative position or sequence that is described by the adjectives. Words such as “comprises” or “includes” are not used to define an exclusive set of elements or method steps. Rather, such words merely define a minimum set of elements or method steps included in a particular embodiment of the present invention.

According to one aspect, the present invention is a spoil-locking coupler system, comprising:

• • a drive element, comprising:
    • a body having a hollow portion with an internal wall and an external wall, the hollow portion defining a socket with a longitudinal axis;
    • a spoil diversion blade extending outward from the external wall;
    • an opening in the hollow body between the internal wall and the external wall and adjacent to the spoil diversion blade; and
    • a first tab-in-groove locking element positioned on the internal wall adjacent the opening; and
  • a coupled shaft having an outer surface that defines a second tab-in-groove locking element connectable to the first tab-in-groove locking element;
  • wherein the coupled shaft is connected to the body of the drive element during powered rotation of the system about the longitudinal axis and into a medium; and
  • wherein the spoil diversion blade is operable to guide spoil from the medium through the opening in the hollow body and into a groove of the first or second tab-in-groove locking element, thereby locking the coupled shaft to the drive element.

Advantages of some embodiments of the present invention include a lighter and more robust coupler system for connecting a drive element or drive head to a coupled shaft, and which system can be assembled faster as separate fasteners such as screws or bolts are not required.

Also, according to some embodiments, the coupler system of the present invention is automatically self-locking, where during a standard pile installation procedure the spoil diversion blade guides spoil into a locking element and locks the system together. Thus, no additional screws, bolts or other fasteners are required.

Also, according to some embodiments, the use of spoil, such as mixtures of clay, rock, sand, and other soils to function as a coupling agent, can enable a coupled system to become more robust over time following installation in the ground. That provides an improved ability to remove an installed system from the ground, such as for environmental site remediation purposes, even many years or decades following system installation.

Further, according to some embodiments, elements of the system of the present invention can be readily fabricated by casting as integral parts, without requiring additional welding, machining or assembly.

Further, according to some embodiments, spoil compaction in the groove can be self-adjusting, so that installation of a pile into harder or rocky ground will result in a more robust compaction of harder spoil into the groove, providing a stronger coupling (e.g., when compared with installations in softer ground) between the drive element and the coupled shaft.

Also, according to some embodiments, compacted spoil in the groove will re-bond over time (including with cohesive soil such as clay and cohesionless soil such as sand, as moisture and metal corrosion in the groove act as a bonding agent), which provides a stronger coupling between the drive element and the coupled shaft. This can be particularly advantageous when piles need to be removed from the ground many years or decades after installation for environmental site remediation.

Those skilled in the art will appreciate that not all of the above advantages are necessarily included in all embodiments of the present invention.

FIGS. 1 and 2 are top and bottom perspective views, respectively, of a blade pile drive head 100, according to an embodiment of the present invention. The drive head 100 can be cast as a single integral part, and includes a hollow body 105 from which extends a first blade 110 and a second blade 115. A distal end of the body 105 defines an attack bit 120 that, during installation of a blade pile, cuts into the ground first.

The first blade 110 and second blade 115 each comprise a leading bevelled edge 125 for cutting into ground below the drive head 100 during installation of a corresponding blade pile. The bevelled edge 125 is adjacent to a transverse bevelled edge 125a that extends outward from the body 105. Both blades 110, 115 also include reversing bevelled edges 130 and transverse bevelled edges 130a, for cutting into ground above the drive head 100 during removal of a pile. The transverse bevelled edge 125a, 130a of each blade 110, 115 extends outward from a blade base 135. Each blade base 135 includes an angled radius to ensure a robust attachment of the blades 110, 115 to the body 105 and to deflect and flow spoil (including, e.g., ground rock, clay, sand and other soils) around the drive head 100.

Four spoil diversion blades 140 extend outward from an external wall 145 of the hollow body 105. Adjacent each spoil diversion blade 140 is an opening 150 in the hollow body 105 between the external wall 145 and an internal wall 155. Further, on the internal wall 155 of the hollow body 105 adjacent each opening 150 is a tab 160 that extends inwardly and away from the internal wall 155.

FIG. 3 is a side perspective view of a main shaft 300 of a pile, according to some embodiments of the present invention. A lower end 305 of the main shaft 300 includes a first groove set comprising a longitudinal groove 310 and two transverse grooves 315. Each transverse groove 315 is joined to the longitudinal groove 310. Notably, each groove 310, 315 is sized to slidably receive at least one of the tabs 160 on the internal wall 155 of the hollow body 105 of the blade drive head 100.

A second groove set (not shown), identical to the first groove set, is pressed into a rear side of the lower end 305 of the main shaft 300, directly opposite the first groove set.

FIG. 4 is a side perspective view of an assembled pile, according to some embodiments of the present invention. As shown, the lower end 305 of the main shaft 300 has been inserted into the hollow body 105. During such insertion, two of the four tabs 160 are received in the longitudinal groove of the first groove set, and the remaining two tabs 160 are received in the longitudinal groove of the second groove set.

Following such insertion, from a view looking downward at the top of the main shaft 300, the main shaft 300 is rotated counterclockwise relative to the blade drive head 100, and each of the four tabs 160 slides sideways along a respective one of the four transverse grooves 315, until each tab 160 abuts a distal end of its respective groove 315.

Each tab 160 and groove 310, 315 thus function as a tab-in-groove locking element that can prevent relative rotation and longitudinal translation between the drive head 100 and the main shaft 300 received in the hollow body 105.

Those skilled in the art will appreciate that according to some alternative embodiments of the present invention, the use of tabs and grooves can be switched, such that the tabs on a drive element can be replaced with grooves, and the grooves on a coupled shaft can be replaced with tabs, while still maintaining a similar tab-in-groove locking functionality.

FIG. 5 is a further top perspective view of the blade pile drive head 100, showing hexagonal sides of a socket 510. During installation into the ground of a blade pile comprising the drive head 100 coupled to the main shaft 300, a drive shaft (not shown) is inserted down the main shaft 300 of the blade pile and a hexagonal distal end of the drive shaft engages six side walls of a hexagonal portion of the socket 510. The other end of the drive shaft is then rotated by a powered, pile installation machine, enabling the drive head 100 and main shaft 300 to be rotated together into the ground.

When the main shaft 300 is fully received in the hollow body 105 (such as shown in FIG. 4), a distal surface of the lower end 305 of the main shaft 300 rests against a shoulder 515 that is positioned at the top end of the socket 510.

FIG. 6 is a top view of the blade pile drive head 100, further illustrating the relative concentric positioning of its elements. In particular, the spoil diversion blades 140 are shown extending away from an external surface of the hollow body 105.

Spoil-Locking Operation

During installation of a blade pile into the ground, as the drive head 100 is screwed into the soil by a drive shaft installed in the socket 510, the attack bit 120 and the leading bevelled edge 125 and transverse bevelled edge 125a of each blade 110, 115 grind against and cut into the soil as the drive head 100 moves downward. The main shaft 300 is also pulled into the ground with the drive head 100 by the force of the tabs 160 against the distal ends of the transverse grooves 315.

Notably, the attack bit 120 can effectively drill a pilot hole, so that when the blade pile is placed in a vertical position and moved into contact with the ground during the initial stages of installation, the pile is less likely to tip away from the vertical orientation, meaning that the correct orientation and position of the pile is easier to maintain during installation. That can improve installation tolerances.

As shown, the attack bit 120 comprises at least one flute 400 that extends along the longitudinal axis 205 of the drive head 100, and can assist in the deflection of drilled spoil. Those skilled in the art will appreciate that the attack bit 120 can comprise various alternative designs and materials depending, for example, on the application and the hardness of the rock or soil in which the drive head 100 will be installed.

During such a pile installation process, loosened spoil (e.g., rock, clay, sand or other soil) that has been cut by the attack bit 120 and the bevelled edges 125, 125a will flow upward along the external surface of the hollow body 105. Such spoil applies a significant pressure against the hollow body 105. However, as the spoil reaches one of the spoil diversion blades 140, the pressure is released into the adjacent opening 150 and the spoil diversion blade 140 guides the spoil into the opening 150. The spoil then flows through the opening 150 and fills the transverse groove 315 that is directly opposite the opening 150. Further rotation of the drive head 100 continues to compact the spoil into the transverse groove 315 and fills the longitudinal groove 310.

FIG. 7 is a side cross-sectional view of the drive head 100, showing the upper and lower spacing between two of the tabs 160. Also illustrated is the positioning of the socket 510 immediately adjacent the blades 110, 115, which enables the direct transfer of power from the drive shaft in the socket 510 to the blades 110, 115.

In particular, as shown, a cutting edge 700 of each spoil diversion blade 140 is angled away from the longitudinal axis, so that the edge 700 is normal to a direction of advance of the cutting edge 700 through a spoil medium as the drive head 100 simultaneously rotates and descends into the ground during a pile installation.

After all the grooves 310, 315 are fully compacted with spoil, all four sides of each tab 160 are then solidly locked into position relative to the main shaft 300 by: a) a distal end of a transverse groove 315, b) a top and bottom edge of the transverse groove 315, or c) spoil that is compacted into the transverse groove 315. The main shaft 300 is thus securely locked to the drive head 100.

If the drive head 100 is later reversed, in an effort to remove the blade pile from the ground, the drive shaft will force the reversing bevelled edges 130 and transverse bevelled edges 130a of the drive head 100 back into the ground. However, the main shaft 300 may be tightly gripped by the soil around its external surface and resist rotation, until the tabs 160 pressing against the compacted spoil in the transverse grooves 315 force the main shaft 300 to also rotate and lift upwards out of the ground.

FIG. 8 is a cross-sectional view through section B-B that is shown in FIG. 7. Two spoil diversion blades 140 are shown extending outward from the external surface of the hollow body 105, and also shown are the adjacent openings 150 through which spoil flows into the grooves 310, 315 of the main shaft 300. Further, the robust qualities of the tabs 160 are shown, which tabs 160 are capable of driving the main shaft 300 rotationally and upwardly during the removal of a pile from the ground.

Those skilled in the art will appreciate that embodiments of the present invention can be manufactured from a wide range of materials, including sand-cast or die-cast steel.

Reference throughout this specification to ‘one embodiment’ or ‘an embodiment’ means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases ‘in one embodiment’ or ‘in an embodiment’ in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

The above description of various embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. Numerous alternatives and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. Accordingly, this patent specification is intended to embrace all alternatives, modifications and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above-described invention.