US 10,590,619 B2 · Helical pier with thickened hexagonal coupling ends and method of manufacture

Abstract

A helical pier and extension shaft, one end of which is formed with a thickened hexagonally shaped female end coupler using a hot forging process that swedges and compresses the walls of the female coupler into a thickened hexagonal configuration, with subsequent heat treatment to recover and enhance yield and tensile strength to the entire main body section and female end coupler of the helical pier and extension shafts. A corresponding hexagonally shaped male coupler may be milled and inertia friction welded to the opposite end of each extension shaft, or alternatively hot forged and internally upset as an integral homogeneous part of each extension shaft, thereby completing construction of the extension shaft with opposing corresponding male and female hexagonal couplers. The forgoing helical pier has particular benefits in applications requiring deep soil penetration and/or when using a grouted helical pier system.

Claims19

Dependent claims

A drive shaft for a helical pier, comprising:

(a) a tubular main shaft section being formed with an initial yield and tensile strength, and having opposite ends and a cylindrical shaft wall formed about a general axis of symmetry;
(b) a terminal coupling section being hot forged homogeneously from one of said opposite ends of said main shaft section, said coupling section having a coupling wall with a hexagonal cross-sectional configuration;
(c) said terminal coupling section being compressed axially along said axis of symmetry during formation to increase the thickness of at least a portion of said hexagonally shaped coupling wall relative to the thickness of said cylindrical shaft wall of said main shaft section;
and
(d) the entirety of said main shaft section and said compressed terminal coupling section being heat treated to a yield and tensile strength greater than said initial yield and tensile strength of said main shaft section.

2 more elements

A method of forming a drive shaft for a helical anchor, comprising the steps of:

(a) providing a tubular main shaft section formed of steel, said main shaft section being formed with an initial yield and tensile strength, and having opposite ends and a cylindrical shaft wall formed about a general axis of symmetry;
(b) hot forging a terminal coupling section homogeneously from one of said opposite ends of said main shaft section, said coupling section be formed with a coupling wall that has a hexagonal cross-sectional configuration;
(c) compressing said terminal coupling section axially along said axis of symmetry to increase the thickness of at least a portion of said hexagonally shaped coupling wall relative to the thickness of said cylindrical shaft wall of said main shaft section;
and
(d) heat treating the entirety of said main shaft section and said compressed terminal coupling section to a yield and tensile strength which is greater than said initial yield and tensile strength of said main shaft section.

2 more elements

Dependencies are inferred from the claim text.

Helical pier with thickened hexagonal coupling ends and method of manufacture

Life of this patent

Helical pier with thickened hexagonal coupling ends and method of manufacture

Life of this patent

Abstract

Claims19