Sacrificial ribs for improved tire wear

Inactive Publication Date: 2003-01-09
MICHELIN RECH & TECH SA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0012] Accordingly, an object of the present invention is to provide shoulder ribs outside both lateral edges of the main tread width which become sacrificial ribs by assuming a larger portion of the load on the tire for a longer period of the tire's tread life due to wear.

Problems solved by technology

Tire stresses from turning and maneuvering the vehicle only exist for a limited time compared with tire stresses from straight ahead highway driving.
However, none of these references disclose a shoulder rib that will reduce the stresses on the first interior rib to delay the onset and reduce the growth of irregular wear over a substantial portion of the life of the tire's tread.
The general problem with the teachings of the art is characterized by the fact that relatively narrow shoulder ribs and narrow grooves separating the narrow shoulder rib from the first interior rib is only effective when the tire is relatively new.
The narrow shoulder ribs quickly wear producing and a relatively large recess so that the narrow shoulder rib does not carry a large enough portion of the tire load after initial wear is experienced.
This problem is not solved with either no initial recess or a large initial recess as the shoulder rib of the tire develops its own stable recess magnitude during the initial wearing process.
Concentrated stresses can produce cracking in the tire's tread which may require the tire to be removed from service before tread wear becomes a problem.

Method used

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  • Sacrificial ribs for improved tire wear
  • Sacrificial ribs for improved tire wear
  • Sacrificial ribs for improved tire wear

Examples

Experimental program
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Effect test

Embodiment Construction

[0038] Referring now in more detail to the drawings, the invention will now be described in more detail. The conventional or reference tire 10 illustrated in FIGS. 1, 3 and 5 has narrow shoulder ribs 18 defined by shoulder grooves 28 at the lateral edges of the main tread. The narrow shoulder ribs are recessed from the main tread portion having ribs 12, 14, and 16 defined by grooves 22, and 24. During normal running of the vehicle, the narrow ribs remain recessed during the life of the tire to maintain a sharp edge 12a on the first interior ribs 12. The overall normal running width of the tire tread is between lateral edges 15. The narrow ribs can collapse on the first interior ribs during maneuvers of the vehicle to support the first interior ribs. These narrow shoulder ribs typical of the art have a coupling effect with the first interior ribs to help maintain a flat lateral or transverse profile of the tire's tread surface. The narrow shoulder ribs wear at essentially the same ra...

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PUM

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Abstract

The present invention provides a tire with a sacrificial rib to protect the main ribs of the tire's tread by delaying the onset of irregular wear and the growth thereof. The improved tire tread comprises a plurality of main ribs formed by grooves extending generally circumferentially around an outer surface of the tire to form a main tread width for contacting the supporting surface. A sacrificial rib is provided for contacting the supporting surface at each lateral side of the main ribs. The sacrificial rib is separated from the main ribs by a narrow shoulder groove having a groove width not greater than about 1.5 millimeter. The sacrificial rib has a surface width in the range of about 2.5 percent to about 12 percent of said tread width. The sacrificial rib has a recess defined by a radial offset from a transverse or lateral profile of the main ribs. The offset has a value in the range of about 0.50 millimeter to about 2.0 millimeters when the tire is new. A shape factor is used for defining the shape of the sacrificial rib where the shape factor has a value between about 0.10 and 0.50.

Description

[0001] This invention relates to vehicle tires, and more particularly to heavy duty truck tires. The invention is particularly useful with long haul trucking operations in reducing the irregular wear of front axle tires.[0002] The problem of irregular wear in long haul truck tires is well known in the art. Truck tires that experience straight ahead driving for a large portion of their life develop wear patterns which are different. Tire stresses from turning and maneuvering the vehicle only exist for a limited time compared with tire stresses from straight ahead highway driving. The axle alignment of the truck as well as compliance of truck suspension and steering linkages become much more important in producing tire wear. Normal stresses can also become as important as the longitudinal and lateral stresses in producing tire wear.[0003] Those patents which disclose various solutions for the problem of irregular wear and endurance in steer axle truck tires include U.S. Pat. Nos. 4,21...

Claims

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Application Information

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IPC IPC(8): B60C11/01B60C11/04B60C11/12B60C11/24
CPCB60C11/01B60C11/12B60C2011/013B60C11/1281B60C11/042B60C11/124B60C11/045Y10S152/03Y10S152/901
InventorRADULESCU, ROBERT CIPRIAN
OwnerMICHELIN RECH & TECH SA