US 5,200,008 AGranted

Radial tire tread and method of mounting a tire with said tread

AssigneeMichelin Recherche et Technique S.A.

InventorsGary D. Enterline, Michel A. de Reynal

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Abstract

The tread design of a radial pneumatic tire for ground vehicles is characterized by lateral or transverse grooves on the shoulder ribs having an incline from the normal to the contact surface in one direction and the lateral or transverse grooves in the center of the tread width being inclined in the reverse direction. Improved wear rates with uniform wear is obtained on a drive axle with proper tire rotation. A reversed direction of rotation on the non-drive axle results in more even wear with potentially less vibration and noise. Lateral grooves are inclined form approximately 20 to 30 degrees and leading edges of some tread blocks have acute angles while other tread blocks have trailing edges with acute angles. The resultant distribution of longitudinal tangential stress on tread blocks is improved.

Claims8

Dependent claims

A pneumatic tire for a vehicle comprising a plurality of circumferential reinforcing belts, subtread rubber and tread rubber all on a radially reinforced carcass between two bead segments, with a tread design having improved contact stresses comprising a plurality of circumferential ribs bounded by circumferential grooves wherein said ribs each have a plurality of laterally extending grooves that define a plurality of tread blocks in series within each rib, characterized by the fact that:

(a) the lateral grooves are inclined with respect to an outer normal to a tread surface in two lateral zones of a tread width defining inclined tread blocks;
(b) the lateral grooves are reverse inclined with respect to the outer normal to said tread surface in a center zone of the tread width defining reverse inclined tread blocks;
(c) the lateral grooves are substantially zero inclined grooves with respect to an outer normal to said tread surface in two intermediate zones of the tread width;
and
(d) when the tire is under load, said inclined tread blocks deform so as to be active in providing a change in tangential stress in a first direction and said reverse inclined tread blocks deform so as to be active in providing a change in tangential stress in a second direction opposite to said first direction.

2 more elements

A method of using a pneumatic tire having a pair of axially spaced apart beads, at least one radial carcass ply extending between and secured to said beads, a belt reinforcing package located radially outward of said carcass ply and a tread portion located radially outward of said belt reinforcing package for engagement with a ground surface, said tread portion comprising:

a tread width having a plurality of circumferential ribs separated and bounded by straight, zigzag or curvilinear circumferential grooves;
a plurality of lateral straight, zigzag or curvilinear grooves having a first incline with respect to an outer normal to a tread surface defining inclined tread blocks for the circumferential ribs within two lateral zones of said tread width;
and
a plurality of lateral straight, zigzag or curvilinear grooves having a second incline with respect to an outer normal to the tread surface, being opposite to said first incline, defining reverse inclined tread blocks for the circumferential ribs within a central zone of the tread width;
a plurality of lateral straight, zigzag or curvilinear grooves having substantially zero inclines with respect to an outer normal to the tread surface for the circumferential ribs within two intermediate zones of the tread width, wherein said method of using said tire comprises the steps of:
a) installing one said tire on each rim of a vehicle;
b) mounting a plurality of said rims on each drive axle of said vehicle such that said inclined tread blocks have a first inclination with respect to a forward driving motion of said vehicle;
and
c) mounting a plurality of said rims on each non-drive axle of said vehicle such that said inclined tread blocks have a second inclination with respect to the forward driving motion of said vehicle, said second inclination being opposite of said first inclination, resulting in improved wear rates and uniformity of the wear that increases the life of said tread portion.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/652,412Filed 7 Feb 1991
Granted: 6 Apr 1993
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

B60C 11/11
Tread patterns: in which the raised area of the pattern consists only of isolated elements, e.g. blocks
B60C 11/01
Tyre tread bands; Tread patterns; Anti-skid inserts: shape of the shoulders between tread and sidewall, e.g. rounded, stepped or cantilevered
B60C 11/0311
Tread patterns: patterns comprising tread lugs arranged parallel or oblique to the axis of rotation
Y10S 152/902
Resilient tires and wheels: non-directional tread pattern having no circumferential rib and having blocks defined by circumferential grooves and…