Tread for heavy-duty radial tires

A radial tire having a rotational axis and a tread, with first and second axially outer edges, said tread having a tread width equal to the distance between said first and second axially outer edges as measured parallel to said axis, said tread extending circumferentially about said axis, said tread comprising:

• (a) a plurality of parallel ribs extending substantially uninterrupted between said first and second axially outer edges, said ribs being inclined to the mid-circumferential plane of said tire and extending over an arc of said tread which is equal to at least about 45 degrees and not more than about 180 degrees;
• (b) a plurality of long, wide grooves extending between said first and second axially outer edges to separate and define said ribs, each said long, wide groove extending alternately in a direction oblique to the circumferential direction of said tire to provide good traction, and then in a direction substantially parallel to the circumferential direction of said tire a distance equal to between one-half and twice the distance said wide groove extends in the oblique direction to provide good tracking;
• and
• (c) a plurality of short, wide grooves located in the portions of said ribs adjacent to said axially outer edges of said tread, one short, wide groove being located between each adjacent pair of long, wide grooves at said first and second axially outer edges, each said short, wide groove being connected through a transverse groove with a short, wide groove located in the portion of a rib adjacent to the opposite axially outer edge of said tread to aid in water evacuation.