Airless flexible tire with torque reducing track pattern

Patent metadata

Field	Value
Publication number	US-10654324-B2
Application number	US-201715822855-A
Country	US
Kind code	B2
Filing date	Nov 27, 2017
Priority date	Nov 27, 2017
Publication date	May 19, 2020
Grant date	May 19, 2020

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.

First claim

Having thus described various embodiments of the invention, what is claimed as new and desired to be protected by Letters Patent includes the following:

1. 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.

2. The wheel assembly of claim 1 , wherein each group includes a single central traction lug annularly spaced equidistant from adjacent drive lugs and exactly two offset traction lugs annularly spaced on either side of the central traction lug.

3. The wheel assembly of claim 2 , wherein the offset traction lugs extend at an angle between 1 degree and 45 degrees from a radial axis so as to extend perpendicular to the ground surface when the distal surfaces of the offset traction lugs contact the ground surface and the airless flexible tire is deflected inward.

4. The wheel assembly of claim 1 , wherein the traction lugs have side surfaces drafted at different angles for maintaining traction with the ground surface.

5. The wheel assembly of claim 1 , wherein the traction lugs are configured to form a corrugated profile in soil of the ground surface for limiting soil erosion.

6. The wheel assembly of claim 1 , wherein the traction lugs are configured to form a sine curve profile in soil of the ground surface for limiting soil erosion.

7. The wheel assembly of claim 1 , wherein the traction lugs are spaced from each other at least a distance of one half of a traction lug width for improving soil shedding when the traction lugs are not contacting the ground surface.

8. 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. The wheel assembly of claim 8 , wherein the tire supports are mounting elements, the drive lugs forming H-shaped ribs for engaging the mounting elements.

10. The wheel assembly of claim 8 , wherein the wheel has a polygon shape such that the tire supports form points of the polygon.

11. The wheel assembly of claim 8 , wherein each group includes a single central traction lug annularly spaced equidistant from adjacent drive lugs and exactly two offset traction lugs annularly spaced on either side of the central traction lug.

12. The wheel assembly of claim 11 , wherein the offset traction lugs extend at an angle between 1 degree and 45 degrees from a radial axis so as to extend perpendicular to the ground surface when the distal surfaces of the offset traction lugs contact the ground surface and the airless flexible tire is deflected inward.

13. The wheel assembly of claim 11 , wherein the traction lugs have side surfaces drafted at different angles for maintaining traction with the ground surface.

14. The wheel assembly of claim 8 , wherein the traction lugs are configured to form a corrugated profile in soil of the ground surface for limiting soil erosion.

15. The wheel assembly of claim 8 , wherein the traction lugs are configured to form a sine curve profile in soil of the ground surface for limiting soil erosion.

16. 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 offse

Assignees

• Lindsay Corp

Inventors

• Fredenburg Michael

Classifications

• B60C11/04

  in which the raised area of the pattern consists only of continuous circumferential ribs, e.g. zig-zag (B60C11/12, B60C11/13 take precedence) · CPC title

• B60C2011/0346

  with zigzag shape · CPC title

• B60C27/0223 Primary

  Studded links, i.e. traction enhancing parts located on the link or inserted into the link · CPC title

• B60C2200/08

  for agricultural vehicles · CPC title

• B60C7/10

  characterised by means for increasing resiliency · CPC title