US20110185649A1

US20110185649A1 - Helical Anchor with Lead

Info

Publication number: US20110185649A1
Application number: US12/698,121
Authority: US
Inventors: Wei-Chung Lin
Original assignee: MacLean Fogg Co
Current assignee: MacLean Fogg Co
Priority date: 2010-02-01
Filing date: 2010-02-01
Publication date: 2011-08-04
Also published as: WO2011092598A3; WO2011092598A2

Abstract

Disclosed herein are embodiments of a lead for a helical pile, comprising, a square shaft attached to the lead, the lead is provided with a base and a plurality of blades, and the blades extend axially from the base and are oriented with respect to one another so as to form more than two angles between each other.

Description

FIELD

Embodiments disclosed herein relate to leads and drives used in civil and utility guy anchors.

BACKGROUND

It is known to use as a helical guy anchor with a helix that rotates about an axis; in such an application, square shaft and its helix act as a screw when the anchor is rotated into soil. In use, an initial guy anchor is rotated about its axis into the soil; after this initial guy anchor is installed, a subsequent anchor can be attached and the assembly is further rotated into the soil with additional anchors attached serially until the anchors collectively provide sufficient resistance for installation of guying cables. However, installers have encountered difficulty penetrating soil and hence advancing these helical anchors into the ground.
One solution is to provide the initial anchor with a lead that helps break up tough soil and remove rocks and other impediments to installation. One such lead utilizes a fin that has been welded onto a square base. However, this arrangement has problems. Because the fin extends in one plane, tough soil and rocks must be moved 180°, thereby exposing the lead to greater torque and bending of the helix. Imperfections in welding process that attaches the fin to the base, as well as imperfections in the integrity of the fin itself, can cause the lead to weaken and eventually fail. Additionally, friction and compression with the soil can lead to heat build-up that also degrades the structural performance of the lead.
Consequently, there exists a need for a lead that breaks up tough soil. There also exists a need for a lead that can withstand the forces inherent in pile installation. Additionally, there exists a need for a lead that breaks up soil, reduces the thrusting force necessary to penetrate soil, and hence reduces bending to the helix. Finally, there exists a need for a lead that dissipates heat more efficiently. Accordingly, the present invention is directed to overcoming the problems set forth above and other problems inherent in prior leads.

SUMMARY

The scope of the present invention is defined solely by the appended claims, and is not affected to any degree by the statements within this summary. Disclosed herein are embodiments of a lead for a helical pile, comprising, a square shaft attached to the lead, the lead is provided with a base and a plurality of blades, and the blades extend axially from the base and are oriented with respect to one another so as to form more than two angles between each other.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a lead.

FIG. 2 is a side view of the base and the blades included with the lead.

FIG. 3 is a bottom view of the base and the blades.

FIG. 4 is a perspective view of the bottom of the base.

FIG. 5 is a top view of the base and the blades.

FIG. 6 is a cross-sectional view of the blades.

FIG. 7 is a bottom view of the base and the blades.

DETAILED DESCRIPTION

The figures provided herein depict a preferred embodiment of the present invention. As shown in FIG. 1, a lead 10 is provided with an axis 11, a base 50, a tip 12, a helix 40 and a plurality of blades 21, 22, 23, 24, designated as a “first blade” 21, a “second blade” 22, a “third blade” 23 and a “fourth blade” 24. The blades 21, 22, 23, 24 extend generally radially from the axis 11, are each provided with a central plane 71, and, as illustrated in FIG. 5, are oriented with respect to one another so that an angle 30 is formed between two blades as measured from each blade's central plane 71. In the presently preferred embodiment, the blades 21, 22, 23, 24 are oriented so that the angle 30 between each blade measures 90 degrees. In an alternative embodiment, however, three blades are provided with the angle 30 between each of them measuring 120 degrees. In the foregoing embodiments, the angle 30 between each blade is equal in magnitude; however, in yet another alternative embodiment, the angle 30 between each blade becomes increasingly greater in the direction of rotation (counterclockwise when viewed from the tip 12, as shown in FIG. 5.)
Referring now to FIG. 1, wherein a perspective view of the lead 10 is shown, blades 21, 22, 23, 24 extend radially, so that each blade generally revolves about the axis 11 through the same volume (unless the lead 10 is advanced axially into the soil, in which case the blades revolve helically through different volumes). Though the presently preferred embodiment is provided with blades 21, 22, 23, 24 that are arranged radially, in an alternative embodiment, the blades are arranged helically about the axis 11, and advantageously arranged along the same path as the helix 40. In such an alternative arrangement, each blade revolves through a different volume.
The blades 21, 22, 23, 24 are generally arranged radially about the axis 11. In the presently preferred embodiment, the central plane 71 of each blade is offset from the axis 11 (which is shown in FIG. 5 as extending out from the page). Within the foregoing generally radial arrangement, each blade is provided an offset 70 from the axis 11 of rotation. Each blade is preferably provided with the same offset 70 in the same direction (i.e. offset to the left or right of the axis 11.) In the preferred embodiment, the offset 70 measures 0.1875 inches as measured from the axis to the central plane of each blade. One of skill in the art will appreciate that the foregoing dimension is scalable, and thus, the offset is roughly 5% of the largest diameter that the blades 21, 22, 23, 24 sweep through when the lead is rotated about the axis 11.
Each blade includes a plurality of sides located so as to face in opposing direction thereby providing each blade with a predetermined width 80. As FIG. 5 illustrates, each blade is provided with a first side 31 and a second side 32. The sides of each blade are generally flat in the preferred embodiment; however, in an alternative embodiment, the sides 31, 32 are curved. Though each side 31, 32 is generally flat, each side is oriented so that the width of each blade decreases as the blade extends radially from the axis 11. Thus, each blade is provided with a taper 81. In the preferred embodiment, the taper 81 measures 10 degrees.
Referring now to FIG. 2, the tip 12 is shown frusto-conically shaped, while in FIG. 5, the tip 12 is shown provided with a cone 13, preferably a cone 13 that flares outwardly at an angle 113 of 120° as the tip extends to the base 50. The blades extend from the tip 12 both in a generally radial and axial direction to an outwardly extending portion 25. Illustrating the radial extent of the blades relative to the sides of the base 50, FIG. 5 shows the base 50 provided with a plurality of corners 125, 122, 123, 124, one of which is an exposed corner (a corner that is not located within the helix 40 but exposed to rocks or soil). FIG. 1 shows the lead 10 provided with an exposed corner 125 after the helix 40 is welded onto the base 50. Referring back to FIGS. 2 and 3 illustrate, the outwardly extending portion 25 is curved and extends beyond the radial extent of the base 50. As a result, FIG. 7 shows the lead 10 provided with a blade radius 120 that is equal to or greater than the base radius 150. Consequently, for at least the reason that the blade radius 120 is equal to or greater than the base radius 150, the outwardly extending portion 25 is configured to push soil away from one of the corners 125, 122, 123, 124, preferably the exposed corner 125.
As noted above, the helix 40 is welded to the base 50, thereby creating an axial weld 145 extending axially up the sides of the base 50 where a curve 140 in the helix 40 meets the side of the base 50, as shown in FIG. 1. The exposed corner 125 is configured to reduce bending and stress at the axial weld 145. The exposed corner 125 pushes soil, rocks, and/or debris away from the curve 140 of the helix 40 (which is also the leading edge of the helix 40). For at least the reason that the outwardly extending portion 25 pushes soil away from the exposed corner 125, and the exposed corner 125 pushes soil, rock, and/or debris away from the leading edge of the helix 40, the outwardly extending portion 25 is configured to distribute the load placed on the leading edge of the helix 40.
The blades 21, 22, 23, 24 are integrally cast with the base 50, which is shaped to cooperate with a shaft 60, such as the shaft 60 of an augur 82. The shape of the presently preferred embodiment is square; however, in alternative embodiments, the shape of the base 50 is out of round, such as a hexagonal shape. The base 50 is provided with a first base end 51 and a second base end 52. The first base end 51 is shaped to cooperate with the augur 82. In the case of the presently preferred embodiment, the first base end 51 is provided with a tapped hole 53 which secures the base 50 to the augur 82.
In the case of the preferred embodiment, the first base end 51 is provided with an inner portion 55 and a fastener-accepting extension 56 located therein. As a result of the hollowed portion 55, the base 50 is divided into a plurality of internal walls 91, 92, 93, 94 (a first internal wall 91, a second internal wall 92, a third internal wall 93, and a fourth internal wall 94) with a plurality of curved transitions 95, 96, 97, 98 (a first transition 95, a second transition 96, a third transition 97, and a fourth transition 98) located therein between. As FIG. 3 illustrates, the first transition 95 is located between the first internal wall 91 and the second internal wall 92; the second transition 96 is located between the second internal wall 92 and the third internal wall 93; the third transition 97 is located between the third internal wall 93 and the fourth internal wall 94, and the fourth transition 98 is located between the fourth internal wall 94 and the first internal wall 91. The transitions 95, 96, 97, 98 are curved in shaped, preferably radiused as each transition extends from one internal wall to another. As FIG. 4 illustrates, the internal walls are provided with a predetermined thickness 99.
As FIG. 2 illustrates, each of the blades 21, 22, 23, 24 also extends both radially and axially from the tip 12 and with each of the blades 21, 22, 23, 24 terminating at the second base end 52. Thus, the edges of the blades impart a sloping profile to the lead 10, as FIG. 2 illustrates. As noted above, each of the blades 21, 22, 23, 24 decreases in width as each blade extends radially from the axis 11. At the same time, the width 80 of each blade increases as each blade extends axially from the tip 12 to the second base end 52.
The second base end 52 is provided with a shaped surface 57. Preferably, the second base end 52 is shaped to penetrate soil. In operation, the shaped surface 57 of the second base end encounters soil before the first base end 51; as a result, the shaped surface 57 extends axially away from the tip 12 towards the first base end 51. Thus, as FIG. 2 illustrates, the shaped surface 57 is oriented at an angle 31 relative to a plane orthogonal to the axis 11. In one embodiment, the shaped surface 57 is frustoconically shaped; in another embodiment, the shaped surface 57 is shaped to form the sides of a pyramid; in yet another embodiment, the shaped surface 57 is provided with an ovoid or egg-like shape. In yet still another embodiment, the shaped surface 57 of the second end 52 is spherically shaped. Finally, in still another alternative embodiment, the shaped surface 57 is helically shaped (advantageously so as to match the helix 40).
Referring now to FIG. 4, the base 50 is also provided with an outer base surface 58. Because the internal walls 91, 92, 93, 94 and the transitions 95, 96, 97, 98 are provided with a uniform thickness 99, the outer base surface 58 is generally shaped according to the inner portion 55 of the inner base 50. The helix 40 is provided with an internal helical edge 41 which is shaped according to the outer base surface 58. Because the internal helical edge 41 is shaped according to the outer base surface 58, the helix 40 is welded to the base 50 where the internal helical edge 41 meets the outer base surface 58.
While this invention has been particularly shown and described with references to embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A lead for a helical pile, comprising:

a) a square shaft that is provided with an axis;

b) a lead;

c) the square shaft is attached to the lead;

d) the lead is provided with a base and a plurality of blades; and

e) the blades extend axially from the base and are oriented with respect to one another so as to form more than two angles between each other.