WO1999014065A1 - Empreintes de pneus non rotatifs de vehicules automobiles et utilitaires legers - Google Patents

Empreintes de pneus non rotatifs de vehicules automobiles et utilitaires legers Download PDF

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Publication number
WO1999014065A1
WO1999014065A1 PCT/US1997/017108 US9717108W WO9914065A1 WO 1999014065 A1 WO1999014065 A1 WO 1999014065A1 US 9717108 W US9717108 W US 9717108W WO 9914065 A1 WO9914065 A1 WO 9914065A1
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WO
WIPO (PCT)
Prior art keywords
tire
load
foo
tread
årint
Prior art date
Application number
PCT/US1997/017108
Other languages
English (en)
Inventor
Anthony John Scarpitti
Michael Alois Kolowski
Frederick William Miller
Donald Woodrow Gilliam
Keith Carl Trares
Original Assignee
The Goodyear Tire & Rubber Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by The Goodyear Tire & Rubber Company filed Critical The Goodyear Tire & Rubber Company
Priority to EP97944414A priority Critical patent/EP1023193A1/fr
Priority to AU45917/97A priority patent/AU4591797A/en
Priority to BR9714858-0A priority patent/BR9714858A/pt
Priority to CA002297991A priority patent/CA2297991A1/fr
Priority to PCT/US1997/017108 priority patent/WO1999014065A1/fr
Priority to ZA988120A priority patent/ZA988120B/xx
Priority to US09/463,834 priority patent/US6443199B1/en
Publication of WO1999014065A1 publication Critical patent/WO1999014065A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
    • B60C11/0083—Tyre tread bands; Tread patterns; Anti-skid inserts characterised by the curvature of the tyre tread
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
    • B60C11/03—Tread patterns
    • B60C11/0327—Tread patterns characterised by special properties of the tread pattern
    • B60C11/0332—Tread patterns characterised by special properties of the tread pattern by the footprint-ground contacting area of the tyre tread
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C19/00—Tyre parts or constructions not otherwise provided for
    • B60C19/001—Tyres requiring an asymmetric or a special mounting

Definitions

  • This invention relates to automobile and light truck tire combinations designed specifically for either the front wheel position or rear wheel position of front engine four wheeled mounted vehicles.
  • Automobile and light track vehicles that have front engines and front steering suspensions have a vehicle weight distribution that is heavily loaded on the front position tires and lightly loaded on the rear position tires.
  • Light truck tires are routinely driven with no weight in the bed of the vehicle causing the rear tire position to typically operate at 50% of the tires rated load. When the truck is carrying weight the load can be increased up to 100% of the tires rated load on the rear tires.
  • Mini-vans and sport utility vehicles in addition to being weight distribution sensitive have higher centers of gravity than automobiles.
  • Tires for the front wheel positions of MPV's are subjected to special demands because of the higher center of gravity of the vehicle and the greater tendency for the vehicle to roll onto the outside shoulders of the tire.
  • the footprint patch of the prior art tire in the front right wheel position (as depicted in Fig. 1) one notes the higher outside contact area of the shoulder 2.
  • the tire geometry has been designed by increasing the tread mass distribution in this portion of the tread to resist the higher pressure and abrasion.
  • the remainder of the tread area is optimized for traction and hydroplaning resistance.
  • This state of the art design approach is embodied in the Wrangler GS-A and Wrangler Aquatred tires and represents the present state of the art in tread designs for MPV's.
  • the rear wheel position of MPV's creates special demands on the tires because of the lighter and variable loading of the tire.
  • the footprint of Fig. 2 depicts the same prior art tire of
  • Fig. 1 when placed on the rear position at 50% load. At this position the centerline pressure of the footprint is highest and needs to resist abrasion. Larger tread elements are needed at the centerline to resist this higher abrasion tendency while still providing traction and hydroplaning resistance by providing open shoulders a design that is in direct conflict with the needs of the front position tire.
  • the rear position can be more fully optimized to resist the fast centerline wear associated with rear wheel drive and light loads while providing high levels of driving traction.
  • the invention employs multiple tread radii contouring the tread to achieve improved tread pressure distribution. Additionally, tread pattern mass is adjusted to enhance anti-hydroplaning performance while still providing resistance to outside shoulder wear. Since front tires encounter water on the road first, they must be more capable of anti-hydroplaning performance than the rear tires that run in their trough or wake.
  • the invention also employs multiple tread radii contouring the tread to achieve full contact of the tire footprint from shoulder to shoulder. This allows for more even tread-wear across the tread with secondary benefits of traction improvement through full tread pattern contact.
  • the invention disclosed below employs not only a distinct tread mass distribution but also teaches a specific footprint shape factor at normal pressure for variable vehicle loading conditions which can be achieved by unique tread arc curvatures for the front position tires and the rear position tires.
  • a pneumatic radial tire combination for four-wheeled automobile or light truck vehicles has a pair of front steer position tires and a pair of rear position tires.
  • Each front steer position tire or rear position tire has a footprint, each footprint has an axial width W, as measured at the lateral extremes of the footprint, a centerplane CP midway between the lateral extremes of the footprint.
  • the tire combination has a pair of front steer position tires and a pair of rear position tires.
  • the front steer position tire has a footprint when the tire is normally inflated for normal load that has a footprint shape factor of greater than 1.00 at a 50 % load, and about 1.00 at both 85 % load and 100% load.
  • the footprint shape factor is defined as the maximum circumferential extent of the tire's footprint at the centerplane of the tire's footprint width divided by the average of the circumferential extent of the tire's footprint width as measured at 40% of the footprint from both sides of the central plane of the footprint.
  • the rear position tire footprint when the tire is normally inflated for normal load, has a footprint shape factor of about 1.00 at 50% load, and 1.00 or less than 1.00 at 85 % load and 100% load when measured similar to the method described for the front position tires.
  • the footprints of each tire is divided into a central region, and a first shoulder and a second shoulder region.
  • the central region extends 20% of the footprint width W on either side of the centerplane CP.
  • Each first and second shoulder region extends from a lateral edge of the footprint to the central portion.
  • the tire combination has the footprint of the steer position tires having a tread contact area at normal inflation and load wherein the central region contact area is less than the contact area of a first or second shoulder area, while the footprint of the rear position tires have a contact area at normal inflation and load in the central region greater than the first or second shoulder portions.
  • the central portion tread contact area of the front steer position tires is less than the first shoulder and the second shoulder contact areas respectively and the central portion of the tread contact area of the rear position tires is greater than the first and the second shoulder contact areas.
  • the central portion of the front steer position tires has a wide circumferential groove having a groove width of about 10 % of the footprint width W at normal load and inflation while the rear position tire has two wide circumferential grooves, one wide groove being located between the contact area of the central portion and the contact area of each first and second shoulder area.
  • the inventive pneumatic radial tire combination for four-wheeled automobile or light track vehicles has a pair of front steer position tires and a pair of rear position tires each tire having an axis of rotation and a casing.
  • the casing has a carcass and a belt reinforcement radially outward of the carcass.
  • a tread is radially outward of the belt structure of the casing.
  • the tread has a pair of lateral edges, a tread arc extending between the lateral edges and a cente ⁇ lane passing midway between the lateral edges and perpendicular to the axis of rotation.
  • the tire combination has a first tread arc for the front position tires and a second tread arc for the rear position tires, the tread arcs defined by a radially outer surface of the treads when the tires are normally inflated but unloaded.
  • the first tread arc has a curvature of maximum radius at the cente ⁇ lane of the tire and a curvature of decreasing radius extending toward the lateral edges, at an intersection of the lateral edge and the tread arc a straight line drawn between the intersection of the tread arc curvature and the cente ⁇ lane is inclined at an angle ⁇ F of greater than 5 ° relative to a tangent line L, L being tangent to the tread arc at the cente ⁇ lane and parallel to the axis of rotation.
  • the second tread arc has a curvature of maximum radius at the cente ⁇ lane of the tire and when measured similar to the tires for the front position has an angle ⁇ R of less than 5° relative to the tangent line L, L being tangent to the second tread arc curvature at the cente ⁇ lane and parallel to the axis of rotation.
  • the front tire position first tread arc curvature extending from the cente ⁇ lane to a lateral edge has at least three radii of curvature R R 2 , R 3 decreasing in size as the curvature extends from the cente ⁇ lane to each lateral edge and the rear tire position second tread arc of curvature has at least two radii R x , R 2 of curvature decreasing in size as the curvature extends from the cente ⁇ lane to each lateral edge.
  • the front tire position radius R is the radius of curvature at the cente ⁇ lane and R 3 is the radius of curvature at the lateral edge. Most preferably R t is greater than twice R 3 . R, of the front tire position is preferably about 600 mm and the tread radius R 3 is greater than 200 mm.
  • the radii of curvature R x , R 2 , R 3 of the front position tires have the following ratio of lateral width to arc width on at least one-half of the tread of less than 50% for R,, and greater than 20% for R 2 and R 3 respectively.
  • the rear tire position is radius R, preferably greater than 800 mm and the radius of curvature R 2 of the rear position tire is less than 200 mm.
  • the radii of curvature R, and R 2 of the rear position tires have the following ratio of lateral width to arc width on at least one tread-half of greater than 50 % for R, and between 30 % to 50 % for R 2 .
  • Asymmetric tread means a tread that has a tread pattern not symmetrical about the cente ⁇ lane or equatorial plane EP of the tire.
  • “Circumferential” means lines or directions extending along the perimeter of the surface of the annular tread perpendicular to the axial direction.
  • Equatorial plane means the plane passing midway between the width of the tread and perpendicular to the tire's axis of rotation.
  • “Groove” means an elongated void area in a tread that may extend circumferentially or laterally about the tread in a straight, curved, or zigzag manner. Circumferentially and laterally extending grooves sometimes have common portions.
  • the "groove width" is equal to tread surface area occupied by a groove or groove portion, the width of which is in question, divided by the length of such groove or groove portion; thus, the groove width is its average width over its length.
  • Grooves may be of varying depths in a tire. The depth of a groove may vary around the circumference of the tread, or the depth of one groove may be constant but vary from the depth of another groove in the tire. If such narrow or wide grooves are of substantially reduced depth as compared to wide circumferential grooves that they interconnect, they are regarded as forming "tie bars” tending to maintain a rib-like character in the tread region involved.
  • Inboard side means the side of the tire nearest the vehicle when the tire is mounted on a wheel and the wheel is mounted on the vehicle.
  • “Lateral” means an axial direction.
  • Net contact area means the total area of ground contacting elements between defined boundary edges divided by the gross area between the boundary edges as measured around the entire circumference of the tread.
  • Net-to-gross ratio means the total area of ground contacting tread elements between the lateral edges around the entire circumference of the tread divided by the gross area of the entire tread between the lateral edges.
  • Non-directional tread means a tread that has no preferred direction of forward travel and is not required to be positioned on a vehicle in a specific wheel position or positions to ensure that the tread pattern is aligned with the preferred direction of travel. Conversely, a directional tread pattern has a preferred direction of travel requiring specific wheel positioning. "Axial" and
  • axially means lines or directions that are parallel to the axis of rotation of the tire.
  • Outboard side means the side of the tire farthest away from the vehicle when the tire is mounted on a wheel and the wheel is mounted on the vehicle.
  • Ring and radially means directions radially toward or away from the axis of rotation of the tire.
  • Rib means a circumferentially extending strip of rubber on the tread which is defined by at least one circumferential groove and either a second such groove or a lateral edge, the strip being laterally undivided by full-depth grooves.
  • Sipe means small slots molded into the tread elements of the tire that subdivide the tread surface and improve traction.
  • Thread element or “traction element” means a rib or a block element.
  • Fig. 1 is a plan view of a footprint of a prior art tire made according to U.S. patent 5,415,215, the tire being normally inflated and loaded representing a front steer position mounting on a light truck or automobile.
  • Fig. 2 is a plan view of a foo ⁇ rint of a prior art tire made according to Fig. 1 the tire inflated for a 100% load as in Fig. 1 but being loaded to 50% representing a lightly loaded rear position mounting on a light truck or automobile.
  • Figs. 3A, 3B and 3C are plan views of the footprints of the front steer position inventive tire, depicting the tire inflated to the 100% load but loaded to 50%, 85% and 100% loads respectively.
  • Figs. 4A, 4B, and 4C are plan views of the footprints of the inventive rear position tire, depicting the tire inflated to 100 % load but loaded to 50 % , 85 % and 100 % loads respectively.
  • Figs. 5 and 6 are cross-sectional views of the preferable embodiments inventive front steer position tire and the rear position tire respectively.
  • Figs. 7 and 8 are plan views of portions of the preferred treads for the inventive front steer position tire and the rear position tire respectively.
  • a prior art tire's footprint or contact patch is shown.
  • the tire shown is the Goodyear Wrangler Aquatred has tread and features disclosed in U.S. Patents 5,415,215 and 5,658,404.
  • the tire footprints were taken at a constant inflation pressure of 35 psi ( 240KPa) which is the inflation at 100% standard maximum or maximum load for the tire shown, a P235/75R15 as specified in the Tire & Rim Association Handbook.
  • 35 psi 240KPa
  • a P235/75R15 as specified in the Tire & Rim Association Handbook.
  • each test tire 10, 20 and the prior art tire used this size tire. After the tire is broken in using the ASTM break-in procedure for the tire the footprint shape can be determined.
  • a tire is either inked and pressed against a paper or cardboard sheet which is laid on a flat hard surface at a fixed load and with the tire inflated at a fixed pressure leaving the impression of the tread on the paper or cardboard surface.
  • This technique of footprinting is old in the tire art and is commonly understood.
  • inkless procedures are also available which include carbonless paper, pressure sensing pads and the like.
  • one of the objectives is to get the tread contacting surfaces within the footprint defined. Once the tire engineer has the foo ⁇ rint shape he or she can make several observations or predictions about the tire and its tread. Historically, the butterfly shaped footprint was determined to be undesirable.
  • the footprints having a shape similar to the bow of a boat were considered desirable for pushing water away from the center of the tread.
  • the prior art tire exhibits this bow shape of foo ⁇ rint.
  • tread element squirm a phenomena known as tread element squirm.
  • the tread elements should have a uniform pressure distribution laterally across the tread and more preferably the leading and trailing edges of the foo ⁇ rint should be axially extending in a straight line path under all operating conditions.
  • the maximum axial width W of the foo ⁇ rint is measured. Then, the distance halfway between the maximum axial width W is defined as the tire's cente ⁇ lane CP. A distance 40% of the tread width (W) on each side of the cente ⁇ lane is located as shown as reference numerals 2, 4. A circumferential line 5, 6 is drawn through points 2-2 and 4-4 respectively and the length of line L ⁇ ! and Lsj is calculated, summed and divided by 2 to arrive at an average shoulder length Lj. The footprint length Lc at the cente ⁇ lane is measured.
  • the foo ⁇ rint shape factor F is the ratio of t-Jl ⁇ .
  • the foo ⁇ rint shape factor F of the prior art tire was 1.12 at normal inflation and normal load, at the same pressure and at 50% load the foo ⁇ rint shape factor F is 1.50.
  • the foo ⁇ rint' s shape is very different at these different loads.
  • This prior art tire employed a large single radius of curvature R, and attempted to optimize the tread mass distribution for a "balanced tire” with very good wear characteristics. Nevertheless, the prior art tire had to be rotated after a period of use to optimize the tread wear rates. The problem is that these tires for light weight trucks face such a wide range of loads particularly on the rear position tires.
  • variable load problem would be to reduce or increase the tire's inflation pressure to match each load condition.
  • a central inflation system could be mounted on the vehicle which could automatically adjust the tire pressure to match the load.
  • the foo ⁇ rint shape would most likely remain almost constant.
  • the drawback to such a system is cost. The consumer would appreciate receiving this neutralizing of load variances at no cost. To achieve this result the tires must become somewhat load insensitive.
  • Figs. 3A, 3B and 3C show foo ⁇ rints of a tire 10 for a front steer position four-wheeled vehicle.
  • Figs. 4A, 4B and 4C show foo ⁇ rints for a tire 20 for a rear position four-wheeled vehicle.
  • each tire is inflated to a constant pressure and then the tire is broken in using ASTM tire break-in procedures. The inflated tire is then loaded to 50%, 85%, and 100% loads and a footprint is taken at each load. The footprint shape factor F is then calculated as previously described.
  • the length Ls-- of the left side of the tire foo ⁇ rint is very close to the same length Ls, as the right side, that is the distance between the points 2-2 and the distance between points 4-4 are about the same. Since one of the objectives is to have the leading and trailing edges being almost axially extending at or during the most typical vehicle load condition for each wheel position it is considered important that the difference in length from point 2-2 relative to point 4-4 does not exceed 10% , more preferably about 5 % or less.
  • the left side 2-2 could be greater in length than the length Lc while the right side is smaller than Lc with the resultant effect being Lc/Ls equaling 1.00 however, in such a case the distance 2-2 would be 105% and the distance 4-4 would be 95 % of the length 1 ⁇ .
  • This asymmetry of the foo ⁇ rint shape can be tolerated as long as the deviation from generally axially extending leading and trailing edges is minimized.
  • the main feature is that the tires 10, 20 when exposed to the most common vehicle load for the wheel position, should have the foo ⁇ rint shape factor within 5 percent or less of the Lc Ls ratio of 1.0 most preferable within 2 % .
  • the inventive front steer position tire 10 has a foo ⁇ rint shape factor greater than 1.00, at the 50% load, and about 1.00 at 85% load and about 1.00 at 100% load.
  • the foo ⁇ rint shape factor was 1.13, 0.99, and 0.98 respectively for the 50%, 85% and 100% loads.
  • the footprints shown in Figs. 4A, 4B and 4C have footprint shape factors of about 1.00 at 50 % load and 1.00 or less at both 85 % load and 100 % load.
  • the foo ⁇ rint shape factors were 1.00, 0.91 and 0.90 for the 50%, 85 % and 100% loads respectively when measured after being broken in.
  • the expected vehicle loads on the tire are typically in the 85 % to 100% standard maximum load range.
  • the four-wheeled front engine mounted vehicles typically exhibit that much weight on the forward portion of the vehicle. Therefore, the foo ⁇ rint shape factor F can very closely be designed to the ideal 1.00 give or take a few percent for the 85% and 100% load. In the exemplary tire 10 this was achieved when the 50% loaded tire 10 had a broken in foo ⁇ rint shape factor F set greater than 1.00, preferably about 10% greater.
  • the tire 20 has the foo ⁇ rint shape factor set at about 1.00 for 50% load and less than 1.00 for the 85% and 100% loaded conditions.
  • the initial 50% loaded foo ⁇ rint shape factor preferably is less than 1.05 with about a .10 drop from the initial 50% loaded condition as the loads increase to 85 % and 100% .
  • Fig. 5 shows the cross section of the tire 10 for the front steer position
  • Fig. 6 shows the cross section of the tire 20 for the rear position.
  • the tires 10 and 20 have very similar structures and are made of similar components.
  • the tires may employ different tread compounds and other component differences more suited for the specific wheel position if so desired.
  • Each tire 10, 20 has an axis of rotation R, a casing 30, the casing 30 has a carcass 32 and a belt reinforcing structure 34 radially outward of the carcass 32.
  • the carcass 32 preferably includes at least one elastomeric ply 36 reinforced with radial cords and an inner liner 35 and a pair of sidewalls 21.
  • the ply 36 is wrapped about two annular bead cores 40 as shown.
  • the tires 10, 20 each have tread 22 located radially outward of the belt reinforcing structure 34 of the casing 30.
  • the tread has a pair of lateral edges 42, 44, a tread arc 46, 48 extending between the lateral edges and a cente ⁇ lane (CP) passing midway between the lateral edges 42, 44 and perpendicular to the axis of rotation.
  • the combination of tires 10, 20 exhibit two distinct tread arcs 46 for the front tire 10 and 48 for the rear tire 20.
  • the first tread arc 46 for the front position tire 10 and the second tread arc 48 of the rear tire 20 are both defined by the radially outermost surface 52 of the tread elements when the tire is inflated but unloaded.
  • the first tread arc 46 has a curvature of maximum radius ⁇ at the cente ⁇ lane CP of the tire 10 and a curvature of decreasing radius R 2 , R 3 extending toward the lateral edges.
  • a straight line 50 is drawn between the intersection 49 of the arc and the cente ⁇ lane CP.
  • the line 50 is inclined at an angle ⁇ F greater than 5° relative to a tangent line L, L being tangent to the tread arc at the centerline CP and parallel to the axis of rotation.
  • both tread halves extending from the cente ⁇ lane CP to the lateral edges 42, 44 have similar curvatures, however, it is contemplated that the curvature could be asymmetric or distinct between tread halves but it is believed that the line 50 should be inclined at an angle ⁇ F . O F being greater than 5° on either side.
  • the tire 20 for the rear position has a line 50 inclined at an angle ⁇ R , ⁇ R being less than 5°.
  • ⁇ R is preferably symmetrical on each tread half in terms of tread arc curvatures although the inventive concept is not limited to a symmetry of curvature.
  • the preferred tire had at least three radii of curvature R R 2 , R 3 extending from the cente ⁇ lane to a lateral edge 42 or 44.
  • the radii R,, R 2 , R 3 decrease in size as the curvature extends from the cente ⁇ lane to each lateral edge.
  • R is the radius of curvature at the cente ⁇ lane, the radius R t extending laterally to less than 50% of the arc width while the radii Rj and R 3 each have lateral width of greater than 20% of the arc width as measured between the cente ⁇ lane CP and the lateral edges 42, 44 or on one-half of the tread as shown in Fig. 5.
  • the tire 10 of the present invention had the R, radius at least twice as large as R 3 , preferably about three times and R 2 falling in between R t and R 3 in size and location.
  • R_ for the test tire 10 was about 600 mm
  • R 2 was about 300 mm
  • R 3 is greater than 200 mm, about 229 mm.
  • the lateral width ratio of R_ was 45.2%
  • R 2 was 24%
  • R 3 was 30.8%.
  • the actual total tread arc width being the sum of 38.12 mm for R 1 ⁇ 20.22 mm for R 2 and 25.9 mm for R 3 or 84.24 mm for each half of the tread as shown in Fig. 5.
  • the resultant shoulder drop at the intersection 47 relative to the line L is about 8 mm and the angle Q F was 5.4°.
  • the tread arc curvature 46 had two radii, R, and R 2 , Rl being greater than 800, or about 834 mm while R 2 was less than 200 mm, or about 175 mm.
  • the lateral width ratios of the curvatures R, and R 2 were greater than 50% for R x and between 30% to 50% for R 2 .
  • the actual test tire R, width to arc width ratio was 61.8% while R 2 was 38.2% on each tread half.
  • the tread shoulder drop off at the intersection 47 was about 7 mm. While ⁇ R was less than 5°, measuring 4.6°.
  • the prior art Wrangler Aquatred had a single tread radius R, of about 433 mm and a tread width ratio of 100% with a total tread arc width of about 80 mm per tread half.
  • the resultant angle ⁇ was 5.3°.
  • the prior art tire was arguably closer to satisfying the angular relationship for the front steer position, however, when one studies the foo ⁇ rint shape factor F as shown in Figs. 1 and 2, a bow shaped footprint outside the desired range is exhibited. This to the inventors means that the prior art tire although a good "balanced tire" failed to optimize the features needed for the combination of unique steer and rear position applications.
  • the final problem solved by the inventors was the placement of and type and shape of the tread elements.
  • Figs. 7 and 8 are plan views of the preferred tread patterns.
  • the tread 22 has a wide circumferential groove 60 in the center of the tread bounded by closely spaced tread elements 70 adjacent the wide groove. If the tread were divided into three equal width zones 80, 81, 82 between the lateral edges 42, 44. The central zone 81 would have a net contact area less than either shoulder zone 80 or 82. While the zone 80 should be equal to or greater in net contact area than the other shoulder zone 82.
  • the rear tire 20 tread as shown in Fig. 8 has two wide circumferential grooves, one such groove 61, 62 being bounded by tread elements 70 and being located with each half of the tread and being spaced laterally about midway of each tread half.
  • the central zone 91 has a net contact area greater than the net contact area of shoulder zones 90 and 92.
  • the shoulder zones 90, 92 have net contact areas about equal as shown with open laterally extending grooves 94 for traction. This combination of tread patterns optimizes the tread wear rates for each wheel position while enhancing snow and wet traction performance.
  • the front tire 10 has a tread arc width slightly narrower than the rear tire 20. This complements the use of only one wide circumferential groove 60 on the front tire. While the wider rear tire employs two such grooves 61, 62, this combination has very pronounced deep-water anti- hydroplaning benefits.
  • the narrower front tire pushes the water out of the way the wider rear tires following in the wake of the front tire sees less water in the center of the tread and a little more in the shoulders zones when traveling at speed. This is a phenomena that is likely to result when a driver suddenly comes upon deep puddle water on a roadway and unexpectedly has no time to reduce speed. These tires greatly enhance the vehicle's ability to track straight without hydroplaning.
  • the inventive front tire 10 is dissimilar to the rear position tire 20 is a multiple of ways.
  • the foo ⁇ rint shape factors, the tread arc curvatures and the tread mass distribution are distinct. These differences due to wheel position sensitivity are noticeable.
  • specific tires for the various wheel positions is common practice.
  • lightweight vehicles such a practice was heretofore avoided.
  • One such way is to provide a harder better wearing tread compound on the front wheel position and a softer more traction sensitive compound on the rear tire.
  • a lower rolling resistant compound can be used on the front wheel position while a superior traction compound is used on the rear.

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  • Mechanical Engineering (AREA)
  • Tires In General (AREA)

Abstract

L'invention porte sur une combinaison de bandages radiaux pneumatiques de véhicules automobiles et utilitaires légers à quatre roues. La combinaison de pneus possède une paire de pneus avant directionnels et une paire de pneus arrière. Le pneu avant directionnel possède une empreinte lorsque le pneu est normalement gonflé pour une charge normale, cette empreinte ayant un facteur de forme supérieur à 1,00 sous une charge de 50 %, et environ 1,00 sous une charge de 80 % et de 100 %. Le facteur de forme d'empreinte est défini comme l'étendue circonférentielle maximale de l'empreinte du pneu au niveau du plan médian de la largeur de celle-ci divisée par la moyenne de l'étendue circonférentielle de la largeur de l'empreinte telle que mesurée sur 40 % de l'empreinte des deux côtés de son plan médian. L'empreinte du pneu arrière, lorsque le pneu est normalement gonflé pour une charge normale, présente un facteur de forme d'environ 1,00 sous une charge de 50 %, et égal ou inférieur à 1,00 sous une charge de 85 % lorsqu'il est mesuré conformément au procédé décrit pour les pneus avant.
PCT/US1997/017108 1997-09-17 1997-09-17 Empreintes de pneus non rotatifs de vehicules automobiles et utilitaires legers WO1999014065A1 (fr)

Priority Applications (7)

Application Number Priority Date Filing Date Title
EP97944414A EP1023193A1 (fr) 1997-09-17 1997-09-17 Empreintes de pneus non rotatifs de vehicules automobiles et utilitaires legers
AU45917/97A AU4591797A (en) 1997-09-17 1997-09-17 Footprints for nonrotatable automobile and light truck tires
BR9714858-0A BR9714858A (pt) 1997-09-17 1997-09-17 Impressões dos desenhos da banda de rodagem para pneumáticos de automóvel e caminhão leve não rotativos
CA002297991A CA2297991A1 (fr) 1997-09-17 1997-09-17 Empreintes de pneus non rotatifs de vehicules automobiles et utilitaires legers
PCT/US1997/017108 WO1999014065A1 (fr) 1997-09-17 1997-09-17 Empreintes de pneus non rotatifs de vehicules automobiles et utilitaires legers
ZA988120A ZA988120B (en) 1997-09-17 1998-09-04 Footprints for nonrotatable automobile and light truck tires
US09/463,834 US6443199B1 (en) 1997-09-17 1998-09-17 Footprints for nonrotatable automobile and light truck tires

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PCT/US1997/017108 WO1999014065A1 (fr) 1997-09-17 1997-09-17 Empreintes de pneus non rotatifs de vehicules automobiles et utilitaires legers

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CA (1) CA2297991A1 (fr)
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1440822A1 (fr) * 2003-01-24 2004-07-28 Sumitomo Rubber Industries Ltd. Bandage pneumatique
WO2011012408A1 (fr) * 2009-07-29 2011-02-03 Societe De Technologie Michelin Vehicule comportant au moins deux essieux dont les roues sont paralleles
CN104442214A (zh) * 2014-12-03 2015-03-25 山东龙跃橡胶有限公司 一种拖车专用轮胎
EP3424751A1 (fr) * 2017-07-04 2019-01-09 Sumitomo Rubber Industries, Ltd. Pneumatique
WO2020066906A1 (fr) * 2018-09-25 2020-04-02 住友ゴム工業株式会社 Pneumatique

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1480962A1 (de) * 1965-12-21 1969-06-19 Continental Gummi Werke Ag Luftbereifung fuer Strassenfahrzeuge
DE3901624A1 (de) * 1988-01-22 1989-08-03 Bridgestone Corp Luftreifen-kombination fuer vierrad-fahrzeuge
EP0502694A1 (fr) * 1991-03-07 1992-09-09 Bridgestone Corporation Combinaison de bandage pneumatique avant et arrière pour kart de course
US5323824A (en) * 1993-03-11 1994-06-28 The Goodyear Tire & Rubber Company Tire/vehicle system
US5415215A (en) * 1989-11-15 1995-05-16 The Goodyear Tire & Rubber Company Asymmetric tire
JPH08188015A (ja) * 1995-01-12 1996-07-23 Bridgestone Corp 車両用前後輪空気入りタイヤ対

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1480962A1 (de) * 1965-12-21 1969-06-19 Continental Gummi Werke Ag Luftbereifung fuer Strassenfahrzeuge
DE3901624A1 (de) * 1988-01-22 1989-08-03 Bridgestone Corp Luftreifen-kombination fuer vierrad-fahrzeuge
US5415215A (en) * 1989-11-15 1995-05-16 The Goodyear Tire & Rubber Company Asymmetric tire
EP0502694A1 (fr) * 1991-03-07 1992-09-09 Bridgestone Corporation Combinaison de bandage pneumatique avant et arrière pour kart de course
US5323824A (en) * 1993-03-11 1994-06-28 The Goodyear Tire & Rubber Company Tire/vehicle system
JPH08188015A (ja) * 1995-01-12 1996-07-23 Bridgestone Corp 車両用前後輪空気入りタイヤ対

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Section Ch Week 9639, Derwent World Patents Index; Class A95, AN 96-388085, XP002065135 *

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1440822A1 (fr) * 2003-01-24 2004-07-28 Sumitomo Rubber Industries Ltd. Bandage pneumatique
CN1301868C (zh) * 2003-01-24 2007-02-28 住友橡胶工业株式会社 充气轮胎
WO2011012408A1 (fr) * 2009-07-29 2011-02-03 Societe De Technologie Michelin Vehicule comportant au moins deux essieux dont les roues sont paralleles
FR2948622A1 (fr) * 2009-07-29 2011-02-04 Michelin Soc Tech Vehicule comportant au moins deux essieux.
CN102470710A (zh) * 2009-07-29 2012-05-23 米其林技术公司 包括车轮平行的至少两个车轴的车辆
US8770601B2 (en) 2009-07-29 2014-07-08 Compagnie Generale Des Etablissements Michelin Vehicle comprising at least two axles, the wheels of which are parallel
CN104442214A (zh) * 2014-12-03 2015-03-25 山东龙跃橡胶有限公司 一种拖车专用轮胎
EP3424751A1 (fr) * 2017-07-04 2019-01-09 Sumitomo Rubber Industries, Ltd. Pneumatique
CN109203865A (zh) * 2017-07-04 2019-01-15 住友橡胶工业株式会社 充气轮胎
US10889149B2 (en) 2017-07-04 2021-01-12 Sumitomo Rubber Industries, Ltd. Pneumatic tire
WO2020066906A1 (fr) * 2018-09-25 2020-04-02 住友ゴム工業株式会社 Pneumatique
JPWO2020066906A1 (ja) * 2018-09-25 2021-08-30 住友ゴム工業株式会社 空気入りタイヤ

Also Published As

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ZA988120B (en) 1999-03-10
CA2297991A1 (fr) 1999-03-25
EP1023193A1 (fr) 2000-08-02
AU4591797A (en) 1999-04-05

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