Vehicle tires having a removable tread

• US 4,289,185 A
• Filed: 11/21/1978
• Issued: 09/15/1981
• Est. Priority Date: 12/23/1977
• Status: Expired due to Term

• Current Assignee: Pirelli Coordinamento Pneumatici SpA
• Original Assignee: Industrie Pirelli SPA
• Inventors: Maiocchi, Luigi, Franchini, Carlo
• Primary Examiner(s): Powell, William A.
• Assistant Examiner(s): Bokan, Thomas
• Application Number:
  US05/962,670
• Time in Patent Office: 1,029 Days
• Field of Search: 152/175, 152/176, 152/187, 152/188, 152/361 R, 152/361 PP, 152/361 DM, 152/354 R
• US Class Current: 152/527
• CPC Class Codes: B60C 11/02 Replaceable treads
• CPC Class Codes: B60C 9/20 built-up from rubberised plies each having all cords arranged substantially parallel

Abstract

A pneumatic tire for a motor vehicle has a removable tread fastened to the casing by annular projections on one locked in annular grooves in the other when the tire is inflated. The tread is supported by a breaker structure underlying the tread in the crown portion of the casing. The breaker has an annular strip of metallic fabric and an annular tape of metallic fabric on each side of the strip and between the annular strip and underlying carcass. There is a free annular central zone between the tapes astride the center plane of the tire.

Claims

1. A vehicle tire having a removable tread comprising a tread ring provided with a circumferentially inextensible annular reinforcing structure having substantially the same width as said tread ring, and a casing with a radial metallic carcass, said casing supporting said tread ring in a radially outer position and maintaining the tread in its position centered with respect to the center plane of the carcass when the casing is under inflation pressure, said casing being provided with an annular breaker structure arranged in a radially outer position with respect to the carcass and being characterized in that said breaker structure comprises only one strip of metallic fabric arranged astride said center plane and substantially as wide as said annular reinforcing structure of the tread ring, the cords of said strip being all parallel to one another and inclined in a predetermined sense with respect to the circumferential direction of the tire at an angle ranging between 45°

and 80°

, and two tapes of metallic fabric, arranged with one at each lateral part of said strip, the axially outer edges of said tapes being substantially coincident with the axially outer edges of said strip to thereby leave free, between their axially inner edges, a central zone centered with respect to the center plane of the casing of a width between 8% and 69% of the maximum width of said breaker structure, the cords of said tapes being parallel to one another in each tape and being inclined at the same angle with respect to the circumferential direction of the tire, but in opposite senses with respect to the direction of the cords of said strip at an angle ranging between 45° and

80°

with respect to the circumferential direction of the tire.

2. The tire of claim 1 characterized in that the axially outer edges of the tapes are externally graduated with respect to the corresponding edges of said strip.

3. The tire of claim 1 characterized in that the axially outer edges of the tapes are internally graduated with respect to the corresponding edges of said strip.

4. The tire of claim 1 characterized in that the cords of the tapes are inclined with respect to the circumferential direction of the tire at angles which are different for each tape.

5. The tire of claim 4 characterized in that the difference in the inclination values of the cords of said tapes with respect to the circumferential direction of the tire does not exceed 30°

.

6. The tire of claim 1 characterized in that the densities of the cords in the strip and in the tapes, respectively, are different.

7. The tire of claim 1 characterized in that the cords of the strip have an ultimate elongation between 4% and 8%.