AIR TIRE Russian patent published in 2010 - IPC B60C11/03 B29D30/06 

FIELD: transport.

SUBSTANCE: invention relates to air tire to be used on icy and snowy roads. Positive effect is provided by air tire that has four main grooves on tread surface that pass along the tire circumference. Note here that said four grooves comprises two first main grooves arranged on LH and RH sides from equatorial plane of the tire, and two second main grooves located outside of said first two main grooves along tire width. Note here that central contact spot is produced between the first main grooves, while intermediate contact spots are produced between first main grooves and second main grooves. Note also that side-zone contact spots are formed outside of the second main grooves along tire width. Slit-like cutouts run across tire width and arranged in each of contact spots with preset spacing along tire circumference. Crosswise groves made on tread surface run across tire width with preset spacing along tire circumference. Note here that each intermediate contact spot has auxiliary groove with its width smaller than that of the first and second main grooves. Note also that auxiliary groove runs along tire circumference. Crosswise grooves comprise LH and RH first crosswise grooves and RH and LH second crosswise grooves arranged on both sides of the tire equatorial plane. Besides LH and RH first crosswise grooves and LH and RH second crosswise grooves are arranged intermittently along tire circumference. Note that RH and LH first crosswise grooves run from central contact spot outward towards tire width and beyond the contact spot between tire and soil. Note that RH and LH second crosswise grooves run from central contact spot outward towards tire width and beyond the contact spot between tire and soil. Note that RH and LH first crosswise grooves have inner extreme ends that are located at a distance from each other on central contact spots. Note that RH and LH second crosswise grooves have inner extreme ends that are located within intermediate contact spots. Tread surface has a surface zone of contact with soil. Note that said surface zone of contact with soil has central section of center zone and side parts of zones located on opposite sides of the zone central part. Note that fraction of grooves, in percent, over the entire zone of contact with soil varies from 18% to 33%. Note here that fraction of the area of grooves in the zone central part, in percent, exceeds that of grooves in the entire surface zone of contact with soil.

EFFECT: air tire with improved operating performances.

11 cl, 4 dwg, 1 tbl, 1 ex