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US 10,654,324 B2Granted
Airless flexible tire with torque reducing track pattern
AssigneeLindsay Corporation
InventorMichael Fredenburg
Life of this patent
Estimating the term…
Abstract
An airless flexible tire comprising a belt, drive lugs, and traction lugs. The drive lugs extend inwardly from the belt and form annularly spaced, rigid, high torque points. The traction lugs extend outwardly from the belt and are annularly offset from the drive lugs so as to form flexible sections that deflect radially inwardly when the tire engages the ground. Each traction lug has an effective height as a function of its actual height, the angle that the traction lug extends relative to a radial axis, the angle of the traction lug's distal surface, and the amount the tire deflects radially inwardly near the traction lug so as to at least partially equalize a rolling radius of the wheel to reduce torque generated near the high torque points.
Claims16
An airless flexible tire for covering a wheel having a number of annularly spaced and outwardly extending tire supports, the airless flexible tire comprising:
- a circular belt having an inner face, an outer face, and left and right sidewalls between the inner face and outer face;
- a plurality of annularly spaced drive lugs extending inwardly from the inner face of the circular belt and each configured to align with and engage one of the tire supports on the wheel so as to form a plurality of annularly-spaced, rigid, high torque points on the airless flexible tire;
- and
- a plurality of annularly spaced traction lugs extending outwardly from the outer face of the circular belt, the traction lugs being annularly offset from the drive lugs so as to be positioned between the tire supports to form a plurality of annularly-spaced flexible sections on the airless flexible tire that deflect radially inwardly when the traction lugs engage a ground surface, each traction lug having an effective height corresponding to an amount the airless flexible tire deflects radially inwardly such that a rolling radius of the wheel is at least partially equalized so as to reduce an amount of torque generated at the high torque points,
- wherein the traction lugs are grouped such that each group includes:
- a central traction lug annularly spaced equidistant from adjacent drive lugs;
- and
- two offset traction lugs annularly spaced on either side of the central traction lug, each traction lug having a distal surface,
- wherein the distal surface of each offset traction lug is angled towards the nearest drive lug so as to be substantially level with the ground surface when the distal surface is in contact with the ground surface at the bottom of a tire rotation and the airless flexible tire is deflected inward.
6 more elements
A wheel assembly for traversing a path along a ground surface having a layer of soil, the wheel assembly comprising:
- a rigid wheel having a plurality of annularly spaced and outwardly extending tire supports;
- and
- an airless flexible tire comprising:
- a circular belt having an inner face, an outer face, and left and right sidewalls between the inner face and outer face;
- a plurality of annularly spaced drive lugs extending inwardly from the inner face of the circular belt and each configured to align with and engage one of the tire supports on the wheel so as to form a plurality of annularly-spaced, rigid, high torque points on the airless flexible tire;
- and
- a plurality of annularly spaced traction lugs extending outwardly from the outer face of the circular belt, the traction lugs being annularly offset from the drive lugs so as to be positioned between the tire supports to form a plurality of annularly-spaced flexible sections on the airless flexible tire that deflect radially inwardly when the traction lugs engage a ground surface, each traction lug having an effective height corresponding to an amount the airless flexible tire deflects radially inwardly such that a rolling radius of the wheel is at least partially equalized so as to reduce an amount of torque generated at the high torque points,
- wherein the traction lugs are grouped such that each group includes:
- a central traction lug annularly spaced equidistant from adjacent drive lugs;
- and
- two offset traction lugs annularly spaced on either side of the central traction lug, each traction lug having a distal surface,
- wherein the distal surface of each offset traction lug is angled towards the nearest drive lug so as to be substantially level with the ground surface when the distal surface is in contact with the ground surface at the bottom of a tire rotation and the airless flexible tire is deflected inward.
9 more elements
A wheel assembly for traversing a path along a ground surface having a layer of soil, the wheel assembly comprising:
- a rigid polygon-shaped wheel having a plurality of annularly spaced and outwardly extending tire supports forming points of the polygon;
- and
- an airless flexible tire mounted on the central hub, the airless flexible tire comprising:
- a circular belt having an inner face, an outer face, and left and right sidewalls between the inner face and outer face;
- a plurality of annularly spaced drive lugs extending inwardly from the inner face of the circular belt and each configured to align with and engage one of the tire supports on the wheel so as to form a plurality of annularly-spaced, rigid, high torque points on the airless flexible tire;
- and
- a plurality of annularly spaced traction lugs extending outwardly from the outer face of the circular belt, the traction lugs being divided into groups, each group being annularly offset from the drive lugs and including:
- a central traction lug spaced equidistant from adjacent drive lugs;
- and
- two offset traction lugs annularly spaced from the central traction lug, the offset traction lugs extending at an angle between 1 degree and 45 degrees from a radial axis such that the offset traction lugs extend perpendicular to the ground surface when the airless flexible tire is deflected,
- each traction lug having an effective height corresponding to an amount the airless flexible tire deflects radially inwardly near the traction lug when the traction lug engages the ground surface such that a rolling radius of the wheel is at least partially equalized so as to reduce an amount of torque generated at the high torque points,
- wherein the traction lugs are grouped such that each group includes:
- a central traction lug annularly spaced equidistant from adjacent drive lugs;
- and
- two offset traction lugs annularly spaced on either side of the central traction lug, each traction lug having a distal surface,
- wherein the distal surface of each offset traction lug is angled towards the nearest drive lug so as to be substantially level with the ground surface when the distal surface is in contact with the ground surface at the bottom of a tire rotation and the airless flexible tire is deflected inward.
13 more elements
Dependencies are inferred from the claim text.