Resilient tires and wheels – Tires – resilient – Armored
Reexamination Certificate
1999-08-03
2001-07-17
Johnstone, Adrienne C. (Department: 1733)
Resilient tires and wheels
Tires, resilient
Armored
C152S526000, C152S529000
Reexamination Certificate
active
06260593
ABSTRACT:
BACKGROUND OF THE INVENTION
TECHNICAL FIELD
The invention relates to a pneumatic race tire and more particularly to a race tire reinforced by a thin annular composite band located in the tread area of the tire which provides a compression element replacing the heretofore stiff belt packages currently used on race tires.
BACKGROUND INFORMATION
Currently race tires use rubber reinforced with nylon, polyester, aramid, or other similar reinforcing cords embedded in a layer of the rubber to form a flexible belt package which is molded beneath the vehicle tread in combination with body plies that extend on a bias underneath the belt to stiffen the tire in order to carry the high loads that a race tire must transmit in cornering, driving, and braking applications.
Race tires are generally for use on dry pavement and thus do not have a tread pattern in order to provide better adhesion to the road surface. The tread gauge is extremely thin, for example, less than 0.5 inches, to avoid the heat that would be generated internally by a thicker rubber tread. When deflected or strained a piece of rubber will generate heat internally. Thus, deflections of the tread rubber in the footprint would lead to excessive heat generation in the tread area which would cause the tread to degrade and blister rapidly if a relatively thick rubber tread is utilized. Thus, race tires use the lightest weights and gauges of materials wherever possible to avoid heat generation. For example, at speeds of 120 mph, the tire turns approximately 26 times a second. Thus, excessive heat could be generated in the footprint area and throughout the tire if an excessively thick rubber tread is utilized.
Furthermore, the belt area of a race tire must be as strong as possible since it has to transmit high comering, driving, and braking forces to the pavement while at the same time being strong enough to resist the centrifugal force being exerted on the tire. For example, the rotational rate of an lndy-type race tire can exceed 40 hz at speeds over 220 mph. Throughout a race the tire is operated constantly at its limit of grip and at elevated temperatures with the race cars transmitting up to 800 hp through the two rear tires severely stressing the rear tires.
Thus, it is advantageous to provide a race tire which is able to use a relatively thin thickness of rubber in the smooth tread area yet has sufficient internal structure to provide the higher load carrying capability and extreme forces and heat which it experiences during the course of a race.
Various pneumatictires for usual passenger-type vehicles have incorporated a thin annular band which extends circumferentially throughout the tire beneath the tread area which, in addition to providing strength to the tire, provides a more puncture resistant tire and a tire able to run after loss of internal air pressure. Some examples of these prior art banded run flat tires are shown in U.S. Pat. Nos: 4,111,249; 4,318,434; 4,428,411; 4,456,048; 4,459,167; 4,673,014; 4,734,144; 4,794,966 and Japanese patent application No. JP63141809. Although these banded tires have proved to have some success for use in passenger tires such a band element has yet to be considered for use in or incorporated for use in a race tire to achieve increased performance.
SUMMARY OF THE INVENTION
Objectives of the invention include providing an improved race tire having an internal compression band which reduces the need for rubber as a structural member, thereby when deflected in the footprint, it generates a reduced amount of heat than that generated by stiffening bands using rubber as an element thereof.
Another objective of the invention is to provide such a race tire which eliminates at least two of the reinforcing belts used in the tread area of the tire, which further reduces the amount of heat generated in this area of the tire to provide increased life to the race tire.
Still another objective of the invention is to provide such a race tire which does not appreciably change diameter with increased speed as a conventional race tire since the conventional fire reinforcing belts deflect a greater amount under the centrifugal loading caused by high speeds, wherein the band element of the present invention is stiff enough to carry the centrifugal loads without significant deflection or growth.
A further objective of the invention is to provide such a race tire in which the band element is lighter in weight than the belt packages it will replace which will lead to better acceleration and braking performance of the race vehicle due to the lighter weight and lower moment of inertia of the tire.
A still further objective of the invention is to provide such a race tire in which the internal band element will more uniformly distribute the forces occurring at the footprint into the body plies of the tire due to the higher stiffness of the band, and in which this uniform distribution of the footprint forces will lead to higher load carrying capability and higher comering stfffness as compared to a race tire using a conventional belt package containing rubber and internal nylon reinforcing cords.
Another objective of the invention is to provide such a race tire in which the internal band element is formed of graphite fibers imbedded in a suitable matrix or resin such as thermoplastic or thermosetting plastic material, wherein the band is made up of multiple layers of fiberwith each layer having a bias angle or orientation relative to the tire axis thereby having a high “out of plane” bending stiffness which enables it to carry higher loads and disperse the load further away from the footprint.
A further objective of the invention is to provide such a race tire in which the band element is made of metal, such as steel or aluminum, fiberglass or a hybrid of high strength, lightweight materials.
Still another objective of the invention is to provide such a race tire in which the internal band element provides higher load carrying capability, increased cornering stiffness, lower rolling resistance, increased resistance to puncture, improved uniformity, less growth at higher speeds, uniform footprint pressure, and moving the occurrence of standing wave phenomenon to a higher speed than race tires using conventional rubber reinforced belt packages.
These objectives and advantages are obtained by the improved pneumatic race tire of the present invention, the general nature of which may be stated as including an elastomeric casing with a tread formed in a crown portion thereof, sidewalls extending from shoulder areas of the crown portion to a pair of spaced bead areas, a body ply carcass extending continuous between the bead areas through the sidewalls and crown portion, said improvement including a continuous thin annular band formed of a high strength, lightweight material located radially inwardly of the tread and between said tread and body ply carcass.
REFERENCES:
patent: 3850219 (1974-11-01), Snyder
patent: 4111249 (1978-09-01), Markow
patent: 4318434 (1982-03-01), Markow
patent: 4428411 (1984-01-01), Markow et al.
patent: 4456048 (1984-06-01), Markow et al.
patent: 4459167 (1984-07-01), Markow et al.
patent: 4673014 (1987-06-01), Markow
patent: 4734144 (1988-03-01), Markow
patent: 4794966 (1989-01-01), Markow
patent: 5879484 (1999-03-01), Spragg et al.
patent: 6012498 (2000-01-01), Koch
patent: 6112791 (2000-09-01), Spragg et al.
patent: 6117258 (2000-09-01), Spragg et al.
patent: 6148885 (2000-11-01), Spragg et al.
patent: 0 114 460 A2 (1984-08-01), None
patent: 0 191 124 A1 (1986-08-01), None
patent: 0 200 055 A2 (1986-11-01), None
patent: 0 357 826 B1 (1990-03-01), None
patent: 0 372 677 A2 (1990-06-01), None
patent: 0 537 780 A2 (1993-04-01), None
patent: 0 664 229 A1 (1995-07-01), None
patent: 0 853 009 A2 (1997-11-01), None
patent: 61-69437 (1986-04-01), None
patent: 6-16008 (1994-01-01), None
Derwent Abstract of EPO Publication 0 191 124*.
*Derwent Abstract provides English language explanation per 37 CFR 1.98(a)(3).
Chaplin Gregory D.
Harrigle, Jr. Dale R.
Kirby James M.
Spragg Charles D.
Bridgestone Firestone Research, Inc.
Johnstone Adrienne C.
Kingsbury Thomas R.
Sand Michael
LandOfFree
Race tire containing band element does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Race tire containing band element, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Race tire containing band element will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2517883