MXPA99005627A - Sacrificial ribs for improved tire wear - Google Patents

Abstract

The present invention provides a tire with a sacrificial rib (38) to protect the main ribs of the tire's tread by delaying the onset of irregular wear and the growth thereof. The improved tire tread comprises a plurality of main ribs (32, 34, 36) formed by grooves (42, 44) extending generally circumferentially around an outer surface of the tire to form a main tread width for contacting the supporting surface. A sacrificial rib (38) is provided for contacting the supporting surface at each lateral side of the main ribs. The sacrificial rib (38) is separated from the main ribs (32, 34, 36) by a narrow shoulder groove (48) having a groove width not greater than about 1.5 millimeter. The sacrificial rib (38) has a surface width in the range of about 2.5 percent to about 12 percent of said tread width. The sacrificial rib (38) has a recess defined by a radial offset from a transverse or lateral profile of the main ribs (32, 34, 36). The offset has a value in the range of about 0.50 millimeter to about 2.0 millimeters when the tire is new. A shape factor is used for defining the shape of the sacrificial rib (38) where the shape factor has a value between about 0.10 and 0.50.

Description

SACRIFICATORY REBOUNDS FOR IMPROVED WEARING OF A TIRE Field of the Invention This invention relates to vehicle tires, and more particularly to heavy-duty truck tires. The invention is particularly useful for long-distance road transport operations, in the reduction of irregular wear of the front axle tires.

Background of the Invention The problem of uneven wear in long-stroke truck tires is well known in the art. Truck tires that experience a forward momentum in a straight line for a large part of their useful life develop wear patterns that are different. The tire tensions of turns and maneuvers of the vehicle only exist for a limited time compared to the tensions of the tires of driving on straight ahead motorways in a straight line. The Rßf.30561 alignment of the axle of the truck as well as the adaptation of the suspension of the truck and the links or links of the steering becomes much more important in the production of tire wear. Normal stresses can also become as important as longitudinal and lateral stresses in the production of tire wear. Those patents that describe various solutions for the problem of irregular wear and strength in truck tires of the steering shaft include U.S. Pat. Nos. 4,214,618; 4,480,671; 4,890,658; 5,010,936; 5,099,899 and 5,131,444, French Patent No. 2,303,675 (FR675), British Patent No. 2,027,649 (GB649), Japanese Patent No. 3-253408 (JP408) and PCT Patent Application No. 9202380-A (PCT380). These references describe means for controlling the shape of a protruding area of a tire rim in an effort to limit the onset of irregular changes in the shape of the tire when the tire wears (i.e. rail or rail transport wear). ). The use of protruding notches of various sizes and in various places where the rim contact area undergoes a transition to the protruding area is described. However, none of these references discloses a protruding flange which will reduce stresses on the first inner flange to retard the start and reduce the growth of uneven wear during a substantial portion of the tire rim's life. The use of narrow protruding shoulders on the truck tire of the front steering axle to control the wear on the major circumferential flanges is known in the art. The general problem with the teachings of the art is characterized in that the relatively narrow protruding ridges and the narrow notches separating the narrow projecting flange of the first inner flange are only effective when the tire is relatively new. The narrow protruding ridges wear out rapidly producing a relatively large recess so that the narrow protruding flange does not carry a sufficiently large portion of the tire load after initial wear is experienced. This problem is not solved either with an initial recess or a large initial recess because the protruding flange of the tire develops its own magnitude of stable recess during the initial wear process. To improve tire wear and tire strength, the use of wider and somewhat narrower protruding ridges has been described in Australian Patent No. 622983 (AU983), PCT Application No. 9202380-A (PCT380) and the Japanese Patent No. 2-253408 (JP408). These references are described in more detail in the following paragraphs. Australian Patent AU983 describes a tire for vehicles traveling long distances at sustained speed with medium to large loads on the tires. The service life during rim wear is improved by including narrow projecting notches having a width of 3.5 millimeters, the wide protruding ridges each having a width of at least 13 percent of the total contact width and a protruding flange recess which has a value between 0.5 and 5.0 millimeters. The width of the protruding flange described is relatively large; it is at least 35 millimeters for a tire with a main rim width of 200 millimeters. PCT application PCT380 discloses a truck tire for long runs at sustained speeds, which has an increased resistance to separation between the reinforcement layers of the lower rim. The separation resistance is improved by narrow protruding notches having a width of between 0.6 and 8 millimeters, the wide protruding ridges have a width between 17 and 34 millimeters and a recess of the protruding flange has a value of less than 40 percent of the depth of the notches of the main rim. Again the width of the projecting flange is relatively large and the preferred recess is also relatively large. Japanese Patent JP408 discloses a tire with reduced abrasion of the projecting part and a reduced penetration depth of the sand. Abrasion resistance is obtained by including thin narrow protruding notches with a notch width from 0.2 to 3 percent of the width of the main rim, the projecting rims have a width greater than 90 percent of the depth of the main notch , of the portion of the main rim, with a contact surface area inclined between 20 and 60 degrees, but the patent does not mention the magnitude of the recess of the protruding rim. The inclined contact surface area of the projecting ridge is at least 20 degrees to help prevent the depth of penetration of the sand as well as the fracture and tearing of the notches. Another design feature known in the art to assist the tire rim in increasing rim life by reducing uneven wear is the addition of spaced apart leaks or grooves extending laterally toward the major ridges of the major grooves, as well as as from the narrow projecting notches towards the first inner flanges. This placement of filtrations or grooves can be improved by means of leaks or inclined grooves which are inclined in the direction of the depth of a normal line with respect to the surface of the tire rim. The placement of leaks or inclined grooves is described in Japanese Patent No. 5-338418 (JP418) and AU983. In JP418 the leaks or inclined grooves are positioned so that they have an internal end which is left behind the surface end during the forward rotation of the tire. This filtration or inclined groove is used to reduce the rigidity of the flange. No filtration or groove placement is indicated adjacent to part 2 of the narrow projecting end (Fig. 1). The placement of leaks or inclined grooves described in AU983, are inclined at an angle with respect to the normal line on the surface of the rim between 5 and 25 degrees. The placement of filtrations or grooves of this reference is used in combination with a very wide projecting flange as previously described. In yet another design feature, known in the art because it helps the tire rim to increase the life of the rim by reducing uneven wear, the rim design controls the amount of normal load on the main rims by the addition of a stepped or gradual flange which is placed adjacent to the flange or flanges to be protected. In the description of US444, the stepped or stepped flange zones contact the ground within the portion in contact with the ground of the width of the main rim to help support the load of the tire. The total width of the stepped or graduated zones is in a range from 5 to 25 percent of the contact area with the tire floor and the stepped or graduated zones have a recess which is proportional to the load on the tire and the tire. gauge of the rim and inversely proportional to the contact area of the rim and the modulus of elasticity of the rubber or rubber of the rim. Reduced values of 2 millimeters or greater are used. The contact of the stepped or gradual zone with the ground, is based on contact with at least 50 percent but less than 200 percent of the maximum load on the tire rim. Each stepped or stepped zone is within the rim contact portion of the rim and is limited by two narrow notches or narrow cuts and the ground contact portions bearing the load encompass the full lateral width of the tire. The description of US444 does not mention anything about the width of the notches and narrow cuts, nor about the use of stepped or gradual areas on the side edges of the tire rim. Another patent disclosing a rim design that controls the amount of normal load taken by a stepped or stepped shoulder which is placed adjacent to the flange or flanges to be protected, is British Patent No. 532,534 (GB534). The notches between the flanges carrying the load have thinner ridges which are spaced apart from the flanges carrying the load by narrow notches of approximately 0.8 millimeters in width. The thinner rims can be reduced but no value is given for the magnitude of the recesses. The GB534 patent does not mention anything about the recessed rims on the side edges of the rim. There remains a need to have a protruding flange which becomes a sacrificial flange that maintains contact with the floor surface to reduce the loads taken by the width of the main rim, especially the first interior rim. A means for maintaining a load on the protruding ridges can effectively reduce stresses on the main rims of the truck axle of the steering axle during straight line driving or forward transport. What is needed is to make the tire wear more uniform through the tire rim. The first inner rim width flange on each side portion of the tire is subjected to high loads which produce relatively large stresses which need to be reduced to improve wear on this first inner rim to cause uniform or even wear. Accordingly, an object of the present invention is to provide protruding ridges off both side edges of the width of the main rim which become sacrificial rims assuming a larger portion of the load on the tire for a longer period of time than the rim. useful life of the tire rim, due to wear. In particular, it is an object of the present invention to teach the appropriate shape and dimensions of sacrificial ridges and narrow protruding notches of a new truck tire so that sacrificial ridges remain effective in protecting the portion of the main rim of the vehicle. tire after the tire starts to wear. A further object of the present invention is to provide sacrificial side protruding ridges for truck tires, to reduce irregular wear on the first inner rims. The sacrificial ridges are to help retard the onset of irregular wear of the main ridges and the growth of the same. Another object of the present invention is to reduce the onset of irregular wear of the truck tires of the steering shaft during large travel operations. Initial wear or rail transport adjacent to the circumferential grooves is of primary interest. Still another object of the present invention is to construct a truck tire having a belt pack, a frame, bead areas and side walls including sacrificial ridges and narrow protruding notches to improve the reduction in irregular wear of the area of the tire. the main rim of a tire, which leads to a uniform wear pattern across the width of the rim of the main tire.

Brief Description of the Invention The above objects are achieved in accordance with the present invention by providing a tire with a sacrificial rim to protect the main rims of the tire rim by retarding the onset of irregular wear and the growth thereof. In one embodiment of the present invention, an improved rim for a heavy duty tire is provided. The tire has a frame extending between the spaced apart heel cores, a central crown area outside the frame with a belt pack to help support the rim in contact with a supporting surface. The improvement comprises a plurality of major ridges formed by notches that generally extend circumferentially around an outer surface of the tire to form a width of the main rim to contact the support surface. A sacrificial rim is provided so that the supporting surface contacts at each side portion of the main rims. The sacrificial rim is a protruding rim spaced apart from the main rims by a protruding notch having a notch width not greater than about 1.5 millimeters. The sacrificial rim has a surface width in the range of about 2.5 percent to about 12 percent of the width of the rim. The sacrificial rim has a recess defined by a radial runout of a transverse profile of the main rims. De-centering has a value in the range of approximately 0.5 millimeters to approximately 2.0 millimeters when the tire is new. These improvements reduce irregular wear on the tire. In another embodiment of the present invention, a tire rim for a heavy-duty truck tire is used on a steering axle of a driven vehicle in a large-stroke operation to improve tire wear. The tire rim comprises a main rim portion having at least four circumferential rims over a width of the main rim separated by main notches having a depth of the main groove extending around an outer surface of the tire between the side edges of the width of the main tire. A surface of the main rim portion defines a side profile of the main rim. A pair of sacrificial rims, one on each side edge of the rim, are spaced apart from the width of the rim by a narrow protruding notch adjacent to each of the side edges. Each sacrificial rim has a width of the lateral surface in a range of values between about 10 millimeters and about 17 millimeters. The narrow projecting notch has a lateral width in a range of values between about 0.2 millimeters and about 1.5 millimeters and a narrow notch depth between about 90 percent to about 110 percent of the depth of the main notch. The narrow notch has an enlarged portion at one end radially inward of the narrow notch to reduce fractionation at this end radially inwardly. The sacrificial rim has a radially inwardly recessed surface area of the tire defined by a radial offset from a uniform extension of the side profile. The runout has a value in the range of about 0.5 millimeters to about 1.5 millimeters, where tire wear of the truck tire is improved.

Description of the Drawings The construction designed to carry out the invention will be described hereinafter, along with other features thereof. The invention will be understood more fully from a reading of the following specification and by reference to the appended drawings, which form a part thereof, wherein an example of the invention is shown and wherein: Figure 1 is a fragmentary plan view of a conventional tire showing an existing rim configuration as a reference; Figure 2 is a fragmentary plan view of the tire of this invention showing a new rim configuration; Figure 3 is an enlarged segment of the reference tire of Figure 1 showing the details of the rim; Figure 4 is an enlarged segment of the tire of the invention showing the details of the rim; Figure 5 is a radial cross-sectional view of the reference tire of Figure 1 taken in a protruding position along the line 5; -5; Figure 6 is a radial cross-sectional view of the tire of the invention taken in a protruding position along the line 6-6 of Figure 2; Figure 7A is a radial cross-sectional view of either the reference tire or the tire of this invention, taken in an inner major notch along the line A-A of the Figures 1, 2, 3 or 4; Figure 7B is a radial cross-sectional view of either the reference tire or the tire of this invention, taken in an inner major notch along line B-B of the Figures 1, 2, 3 or 4; Figure 7C is a circumferential cross-sectional view of a crown portion of the tire of this invention, taken parallel to and close to a narrow projecting notch along the line C-C in Figure 2; Figure 8 is a radial cross-sectional view of the tire of this invention showing half of a tire if it is taken along line 8-8 of Figure 2; Figure 9 is a graphical diagram showing an average longitudinal stress distribution as a function of a contact length of a first inner rim of the tire of this invention and a conventional tire obtained using a finite element model, the rim is in contact load with a support surface; Figure 10 is a graphical diagram showing a distribution of the average lateral tension as a function of the contact length of a first inner rim of the tire of this invention and a conventional tire obtained using a finite element model, the rim is in contact loaded with a support surface; Figure 11 is a graphical diagram showing an average normal stress distribution as a function of the contact length of a first inner rim of the tire of this invention and a conventional tire obtained using a finite element model, the rim is in contact loaded with a support surface. Figure 12 is a graphical diagram showing an average longitudinal stress distribution as a function of a contact length of a first inner rim of the tire of this invention and a conventional tire obtained by the actual tire tests, the rim is in contact loaded with a support surface; Figure 13 is a graphical diagram showing an average lateral stress distribution as a function of the contact length of a first inner rim of the tire of this invention and a conventional tire obtained by the actual tire tests, the rim is in contact loaded with a support surface; and Figure 14 is a graphical diagram showing an average normal stress distribution as a function of the contact length of a first inner rim of the tire of this invention and a conventional tire obtained by testing the actual tires, the rim being in contact loaded with a support surface.

Description of one of the Preferred Modalities Referring now to the drawings in more detail, the invention will be described in greater detail. The conventional or reference tire 10 illustrated in Figures 1, 3 and 5 has narrow protruding shoulders 18 defined by the protruding notches 28 and the side edges of the main rim. The narrow protruding ridges are recessed from the portion of the main rim having ridges 12, 14, and 16 defined by the notches 22, and 24. During normal running of the vehicle, the narrow ridges remain reduced during the tire's useful life for maintaining a sharp edge 12a on the first inner rims 12. The width of the complete normal run of the tire rim is between the side edges 15. The narrow rims can sink on the first inner rims during the maneuvers of the vehicle to support the first interior rims. These narrow protruding shoulders typical of the art have a coupling effect with the first inner rims to help maintain a flat lateral or transverse profile of the surface of the tire rim. The narrow protruding ridges wear out essentially at the same speed as the main rim portion to maintain a stable radial offset or recess from the profile of the main rim. Nevertheless, the stable runout value is relatively large and the stresses on the first inner rims 12 can remain relatively large, especially after the tire has run for a relatively long period of time. The present invention satisfies a need to limit these stresses and can remain throughout the life of the tire to improve the onset of uneven wear. The tire 30 of this invention has protruding sacrificial ridges 38 which are relatively wide as illustrated in Figures 2, 4 and 6. The sacrificial ridges are formed by relatively narrow protruding notches 48. The lateral width C of each sacrificial ridge has a value between a range of values of about 2.5 percent to about 12 percent of the width of the main rim TW (Figure 8). The preferred range of the C values is between about 5 percent and about 10 percent. The lateral width of the sacrificial rim of a typical heavy duty truck tire has a value of between about 5 millimeters to about 20 millimeters within the scope of this invention. The surface width C of the sacrificial rim is in a range of about 10 millimeters to about 17 millimeters. The lateral width C of the sacrificial rim can vary from about 2.5 percent to about 12 percent of the width of the main rim of the tire rim. The lateral width of the narrow protruding notch can have a value as large as 1.5 millimeters within the scope of this invention. The width of the narrow projecting notch 48 has a preferred width value G less than or equal to about 1.0 millimeter. In particular, width values G smaller than approximately 0.2 millimeters to approximately 0.4 millimeters, gave optimum improvements in the wear of the irregular tire. The practical values of the width of the narrow protruding notch are in a range of about 0.2 millimeters to about 1.0 millimeter. However, fracturing the notch must be controlled. The portion of the main rim is defined by ridges 32, 34 and 36 defined by the circumferential notches 42 and 44. The sacrificial ridge has an initial recess or minimum radial runout that extends radially inward of the P line of the lateral or transverse profile of the main rim area of 0.5 millimeters (Figures 6 and 8). The recess H of the sacrificial rim radially inward of the portion of the main rim of a new truck tire is preferably in a range of about 1.0 millimeter to about 1.5 millimeters. The recess of an external surface of the sacrificial ridge from the profile line may vary within the scope of this invention. The upper surface of the sacrificial rim may have an inclined angle S with respect to the profile line with a value of less than about 15 degrees. The recess is preferred at a constant distance H from the profile line P, giving an inclined angle of zero degrees (Fig. 6) with respect to the profile line. The zero tilt angle assists the sacrificial ridge to assume a larger portion of the total tire load (see Figure 6). The total normal contact width of the tire rim extends between the side edges 35. The width TW of the rim is defined as the lateral distance between the outer edges of the first inner rims 32 (Figure 8). The width of the rim is the side width portion that supports the main load of the tire rim. The ability of the sacrificial rim to help support the load on the tire is critical in extending the tire's useful life by reducing the amount of uneven wear on the tire rim.

The shape of the protruding area of the tire 30 is better defined by a factor of the shape which refers to the surface width C, the slope M of the projecting part 40 and the depth D-H of the narrow projecting notch 48 (Figure 6). The slope M is further defined by the reference to the illustration of Figure 6A. A line P 'is constructed parallel to the line of the side profile P from the bottom 48a of a narrow projecting notch 48 to intersect the external surface 40 of the protruding part of the tire at a first point 38b of the sacrificial rim 38. The lateral distance K is defined from an axially external side wall 48b of the narrow projecting notch with respect to the first point. A second point 38a of the sacrificial rim is defined at the axially external edge of the upper surface 39 of the sacrificial rim. An inclined straight line 40a is constructed between the first point 38b and the second point 38a. A ratio of the axial extent of the inclined line 40a to the radial extent of the inclined line is defined as the slope M. That is, the slope M is approximately equal to (K-C) / (D-H). Typical values of the slope for the tire of this invention are in a range of values from about 0.1 to about 0.3. The SF form factor defined as SF-M x (D-H) / C, in the company of the width of the narrow notch G, is a good indication of the ability of the protruding part configuration to protect the first inner flange. The depth D of the narrow protruding notch is preferably between about 90 percent and 110 percent of the depth of the main notch D '(Figure 8). The shape factor is such that the load on the tire is supported on a larger part by the sacrificial flange to relieve the stresses on the first inner flange. A factor of the typical SF shape for tires made in accordance with this invention has a value of from about 0.05 to about 0.50, wherein a typical conventional tire or reference tire could have a shape factor of about 1.0 or greater. The preferred value of the shape factor is approximately 0.2. The factors of the sacrificial flange shape of this invention are such that the load on the tire is supported on a larger part by the sacrificial flange to relieve the stresses on the first inner flange 32. Furthermore, the width of the narrow protruding notches 48 is such that the sacrificial ribs 38 contact the first inner ribs 32 during the forward drive in a straight line to additionally support the normal and lateral load on the tire. Referring in greater detail to Figures 4 and 6, the tire 30 of this invention has sacrificial ridges 38 extending beyond the width TW of the area of the main rim. The object is to protect and preserve the area of the main tire against irregular wear and growth during the tire's useful life. As a result, protruding ridges which are sacrificed to carry a larger portion of the tire load during a longer portion of the tire's useful life, provide this protection. The protruding ridges come to be sacrificed because they are more effective for a longer period of time during the useful life of the tire. They wear out in the company of the width TW of the tire rim and the depth H of the radial or recessed runout does not become excessive so that the sacrificial rims continue to maintain contact with the supporting surface during the forward run in straight line of the vehicle. Outstanding sacrificial flanges 38 are designed to relieve the main rims of the tire rim from large stresses; particularly during the straight forward run. In addition, the sacrificial rims of this invention have a geometric configuration that allows them to maintain their effectiveness during a longer portion of the tire's useful life. This is achieved by the main structural features of the sacrificial rim. The first structural feature is the width C of the sacrificial ridge which is relatively large when compared to a larger portion of the art. The second structural feature is the use of a light recess H for the upper surface of the sacrificial rim decentered radially inward from the P line of the side profile of the main rim area (Figure 6). These two structural characteristics are uniquely chosen for the tire of this invention. A third structural characteristic that can be used is the slope M of the portion of the side wall of the sacrificial rim. A fourth structural feature of the invention is the narrow projecting notch 48. This notch has a width G of the recess and a depth D selected to provide protection for the area of the main rim of the tire. The width of the gap is such that the sacrificial rim 38 will contact the first inner rim 32 when the surface of the rim is being loaded. The depth of the narrow protruding groove, which is between about 90 percent and 110 percent of the depth of the major grooves, allows the sacrificial flange 38 to act independently of the first inner flange 32 during the useful life of the tire rim. . The width G of the hollow, relatively small, less than or equal to about 1.5 millimeters, can produce concentrations of the stress at the bottom of the narrow projecting notch. Concentrated stresses can cause fractures in the tire rim which may require the tire to be removed from service before tire wear becomes a problem. A minimum radius for the inner surface of the narrow protruding notches at the bottom of the notches of approximately 1.0 millimeter may be provided to relieve the stress concentrations at the bottom of the narrow protruding notches. A further embodiment of the present invention includes the addition of filtrations or grooves in the side edges of each circumferential flange. This modality combines the structural characteristics of the sacrificial flanges and the narrow protruding notches to improve the protection of the tire against the onset of irregular wear and the growth thereof. The leaks or slots 45 are provided to the outer edge of the first inner flange 32 adjacent the narrow projecting notch 48, as illustrated in Figure 4. The leaks or grooves 46 are provided to the main flanges 32, 34 and 36 adjacent to the flanges. main notches 42 and 44. Filters or grooves 45 and 46 are placed at an angle L with respect to lateral line 32a. The placement of filtrations or grooves extends in one direction from the notches to correspond to the rotation of the tire as illustrated. The lateral angle L has a value in the range of about 15 degrees to about 35 degrees. The filtrations or slots 45 and 46 may also have an inclined angle V backward with respect to a ncmal N with respect to the surface of the rim, as illustrated in Figure 7C.

The inclined angle V with respect to the normal has a value in the range of 0 degrees to approximately 20 degrees. The preferred inclined angle is from about 5 degrees to about 15 degrees. As a part of the present embodiment for the placement of leaks or grooves in the edge, the preferred tire 30 has the same placement of leaks or grooves in all the edges of the main flanges 32, 34 and 36 as illustrated in Figures 2 and 4. However, it is within the scope of this invention to have different filtration locations or grooves for a flange when compared to another flange. The inner circumferential notches 42 and 44 are made to be similar in the preferred embodiment of this invention. The preferred details of the inner notches are illustrated by the cross-sectional views of Figures 7A and 7B. The bottom of the notches can be formed in a sinusoidal configuration extending circumferentially around the tire (Figures 1 and 2). The outer surface edges of the notches are preferably straight. Therefore, the radial side faces of the notches have a variable angle with respect to a circumferential plane CP of the main notches. Preferred leaks or grooves have an edge 46a, 46b within the respective flanges, which are parallel to the circumferential plane of the groove. A cross-sectional view of an example of the tire of this invention is illustrated in Figure 8. The tire 30 is symmetrical with respect to the median plane M of the tire so that only half of the tire can be shown in this section of radial cut. . The tire rotates around the rotary axis AR of the vehicle wheel. The tire includes the rims and notches of the tire rim T as previously described. The rubber materials of the standard rim can be used for the tire of this invention. The width TW of the main rim for the main contact surface area of the tire is protected against irregular wear by the sacrificial rim 38 and the narrow protruding notch 48 as described. A belt pack 60 below the rim has a plurality of belts 62, 64, 66 for the illustrated tire. The belts are typically reinforced with parallel metal cables crossed at an acute angle in each crease with the reinforcement of the adjacent crease. A frame 70 extends down the belt from heel to heel 90 and surrounds a heel core 92. The frame has at least one fold of the frame and preferably multiple foreinforced with metal cables extending generally radially and axially between the heel cores. An area 50 of the side wall having a rubber portion 52 of the side wall extends between each bead and a respective side edge of the belt pack 60. An inner cover fold 80 of a rubber material aids the tire to keep an inflated condition on the wheel of the vehicle. The reduction in stresses on the first inner rims 32 of the preferred tire 30 of this invention is illustrated in the graphs of Figures 9, 10 and 11. The combined effect of the architecture and the tire materials can be modeled and analyzed using a high-speed computer. The results of the tension Sx in a longitudinal direction X on the first inner flange are shown in Figure 9. The longitudinal stresses Sx for the reference tire 10 are shown as the curve 110 and for the present invention are shown as the curve 130. The stresses are plotted as the values of the average stress along the width across the flange as a function of the circumferential distance along the first contact length of the inner flange. The flange is in contact with a support surface and the measurements are referred from the center of the contact length (zero point). These longitudinal stresses show the reference tire and the invented tire having approximately the same longitudinal tension Sx. The voltage Sx also causes the driving forces to be increased for the tire of this invention. The results for the tension Sy in the lateral direction Y on the first inner rim are shown in Figure 10. The tensions Sy for the reference tire 10 are shown as the curve 210 and for the present invention are shown as the curve 230. The stresses are plotted as values of the average stress along the width across the flange as a function of the distance along the first contact length of the inner flange. The flange is in contact with a support surface and the measurements are referred from the center of the contact length (zero point). These lateral stresses show the invented tire present which has much smaller lateral stresses S to the reference tire.

The results for the tension Sz in a normal Z direction on the first inner flange are shown in Figure 11. The normal stresses Sz for the reference tire 10 are shown as the curve 310 and for the present invention are shown as the curve 330 The stresses are plotted as the values of the average stress along the width across the flange as a function of the distance along the first contact length of the inner flange. The flange is in contact with a support surface and the measurements are referred from the center of the contact length (zero point). These normal stresses show the tire 30 of the present invention having normal stresses Sx much lower than the reference tire 10. The combined stresses are calculated to be much lower for the tire of this invention. The actual test values can be compared with these values of the calculated voltage to further verify the improvements of the tire of this invention on the reference tire and others in the art. The results of the actual wear test are also described in the subsequent experimental results section to further verify the present co-automated results of Figures 9, 10 and 11 showing the improvements made by the present invention. The improvement in irregular wear is generally made by the combination of several individual improvements. The widening of the width C of the sacrificial rim and the addition of a recess H for this rim, provides a longitudinal tension Sx beneficial for the first inner rim 32. Also, reducing the recess H of that used for the reference tire 10, the sacrificial flange 38 of the present tire of the invention 30 will wear less; making it beneficial for a longer period in the useful life of the tire. By reducing the distance G of the gap between the sacrificial rim 38 and the first inner rim 32, the rims are made to contact each other to help support the first inner rim and reduce the lateral tension Sy on the first inner rim. Because the sacrificial rim and the first inner rim are essentially fixed together when they are loaded, the edge-rim effects are eliminated and the normal tension Sx on the first inner rim is improved. A joint overall fixation provides a stronger sacrificial flange to add more strength in the high-impact, brush-covered environments over the reference tire. The sacrificial rims of the rim of the tire of the present invention initially wear out at a slower speed than the narrow rims of the reference tire because of its higher radial development (lower radial runout) which will make the sacrificial rims remain beneficial. more durable in the life of the tire.

Experimental Results A conventional or reference tire known in the art was tested in the company of a tire essentially identical to a conventional tire, but having the features of the present invention. The tires were heavy duty truck tires of the same size 275/89 R22.5, loading and use range; as defined by the 1997 Yearbook Standards of The Tire and Rim Association, Inc. of Copley, Ohio. There are two conventional tires and two tires of the invention tested on the steering axles of two identical long-distance vehicles and are rotated between the vehicles to compensate for any differences in the vehicle suspension system. The following results illustrate the improvements provided by the tire of this invention. The conventional tire and the tire of this invention have essentially the same dimensions except for the geometry of the protruding flanges and the narrow protruding notches (see Figure 6). Table 1 shows the geometrical parameters of the conventional tire and the tire of this invention. The depth of the narrow protruding notches is equal to the depth of the notches in the width of the main rim, or approximately 15 millimeters. Filters or grooves were included in the lateral outer edge of the first inner rims with the conventional tire having side angles and zero inclination and the tire of the invention has leaks or grooves with a side angle L of approximately 25 degrees (Figure 4) and the inclined angle V of approximately 10 degrees (Figure 7C). The shape factor for the conventional tire was 0.81 and the tire of the invention had a shape factor of 0.22. Tire testing continued until tire wear on conventional tires was of a magnitude to cause the tires to be removed from service. The right side tires were maintained on the right side of each vehicle when the tires were rotated between the vehicles. Several rotations were used during the trial period.

TABLE I GEOMETRY OF THE OUTSTANDING PART OF THE PNEUMATIC PROOF PARAMETER (mm) PNEUMATIC TESTED WIDTH WIDTH UNDERWEAR NARROW NARROW RIM REBORDE WIDTH PENDING TW SOBRESAH G M LIENTE C PNEUMATIC 197 4.5 2.8 3.0 0.3 CONVENCIO-NAL NEUM TICO 197 12.0 1.5 1.0 0.2 OF THE INVENTION Table II illustrates the relative magnitude of wear for each of the rims of the right side tires and Table III illustrates the relative wear for each of the rims of the left side tires. The magnitudes of the wear are given relative to the first outer inner flange of the conventional tire. The relative mileage values at the time of tire removal from the service are also given in the last column.

TABLE II MAXIMUM RELATIVE WEAR: RIGHT TIRE REBORDE 1 REBORDE 2 REBORDE 3 REBORDE 4 REBORDE 5 MILEAGE NEUMA- EXTERIOR 2 / o. CENTER 2 / o. RELATIVE INTERIOR TICO l / o. INTERIOR INTERIOR l / o. IN THE INTERIOR INDOOR TEST REMOVAL NEUMÁ1.0 1.0 1.0 1.2 2.5 1.0 TICO (ref.) (Ref.) CONV.

NEUMÁ1.5 1.5 1.5 1.7 1.7 1.0 TICO INVENCIÓN TABLE III RELATIVE MXIMO WEAR: LEFT NEUM TICO REBORDE 1 REBORDE 2 REBORDE 3 REBORDE 4 REBORDE 5 MILEAGE NEUMA- EXTERIOR 2 / o. CENTER 2 / o. RELATIVE INTERIOR TICO l / o. INTERIOR INTERIOR l / o. IN THE INTERIOR INDOOR TEST REMOVAL NEUMÁ1.0 0.4 0.3 0.4 0.4 1.0 TICO (ref.) (Ref.) CONV.

NEUMÁ0.6 0.6 0.6 0.6 0.7 1.5 TICO INVENCIÓN The relative wear test results of Tables II and III show a much more uniform wear pattern for the respective flanges of the tire of this invention. For the tires on the right side of the vehicle, the maximum wear was on the first inner flange on the inner side of the tire with respect to the vehicle. They were removed from service at the same mileage, however, wear on the tire of this invention was only 1.7 / 2.5x100 = 68 percent of that for the conventional tire. For the left side of the vehicle, the maximum wear for the conventional tire was on the first inner rim on the outer side of the tire with respect to the vehicle. For the left tire of the invention, maximum wear was on the inner side of the tire as above. The left tire of this invention was removed from service at a mileage of 1.5 / 1.0x100 = 50 percent larger than the mileage of the conventional tire, and tire wear of the invention was only 0.7 / 1.0x100 = 70 percent that for the conventional tire. These results illustrate the dramatic improvements in tire wear of this invention. The actual stress measurements were made for the test tires when compared to the stresses predicted using a finite element model (FEM) and a high-speed computer. The results of the tension of the results of the computer model were described and discussed previously, as illustrated in the graphs of Figures 9, 10 and 11. New graphs showing the relative maximum stresses on the first inner rims resulting from the results of actual or current tests, are illustrated in Figures 12, 13 and 14. The actual test results for the voltage Sx in a longitudinal X direction on the first inner flange are shown in Figure 12. The longitudinal stresses Sx for the conventional tire are shown as the curve 112 and for the present invention are shown as the curve 132. The actual test results for the tension Sy in a lateral direction Y on the first inner flange are shown in Figure 13. The lateral stresses Sy for the conventional tire are shown as the curve 212 and for the present invention are shown as the curve 232. The test results Actual for the tension Sz in a normal direction Z on the first inner flange are shown in Figure 14. The normal stresses Sz for the conventional tire are shown as the curve 312 and for the present invention are shown as the curve 332. The comments General statements made previously about the stresses generated by the FEM computer generally apply to the voltages obtained by the Real test results. Indeed, the graphics are very similar. Table IV shows a comparison between the relative maximum stress on the first inner rims for the conventional tire, compared to the tire of this invention for the tensions Sx, Sy and Sz, in each case.

TABLE IV MAXIMUM RELATIVE TENSIONS ON THE FIRST INTERIOR RIVALS PRESENT NEUM TICO (FEM) CURRENT (EVIDENCE) Sx Sy Sz Sx Sy Sz PNEUMATIC CON- 1.0 1.0 1.0 1.0 1.0 1.0 VENTIONAL (ref.) (Ref.) (Ref.) (Ref.) (Ref.) (Ref .: PNEUMATIC 0.86 0.60 0.70 0.58 0.59 0.71 THE INVENTION In all cases the maximum stresses are lower on the tire of this invention than the stresses on the conventional tire. The same reductions of the general magnitudes in Sx, Sy and Sz are observed for the tire of this invention when compared to the conventional tire in both comparisons. The normal stresses Sz are essential in the control of wear on the first inner rims of the tire. These test results verify the value of the saicial flanges of this invention in reducing wear and extending the useful life of the tire. Although a preferred embodiment of the invention has been desed using specific terms, such a destion is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates.

Having desed the invention as above, property is claimed as contained in the following

Claims (20)

1. An improved tire for a heavy-duty tire, the tire has a frame that extends between the heel cores spaced apart, an area of the central crown outside the frame with a belt packing to help support the tire in contact with a support surface, the improvement is characterized in that it comprises: a plurality of main rims formed by the notches of the main rim that generally extend circumferentially around an outer surface of the tire to form a width of the main rim on a surface of the rim, to make contact with the support surface; a sacrificial flange for contacting the support surface on each lateral part of the width of the main rim, the sacrificial rim separated from the main rims by a narrow projecting notch having a notch width not greater than about 1.5 millimeters; the sacrificial rim has a surface width in the range of about 2.5 percent to about 12 percent of the width of the rim; the sacrificial rim has an external surface recessed from a transverse profile of the main rims by a radial runout, the radial runout having a value in the range of about 0.5 millimeters to about 2.0 millimeters when the tire is new; and the sacrificial rim has a shape factor (SF) defined as the depth (DH) of the narrow projecting notch by the slope (M) of a narrow protruding part of the sacrificial ridge, divided by the width of the lateral surface (C). ), expressed as SF = (DH) x M / C having a value from about 0.05 to about 0.50 with a load on the tire that is supported for the most part by the sacrificial shoulder to relieve stresses on at least one first flange inside the main rims and where the improvement decreases the irregular wear on the tire.

2. The improved tire rim according to claim 1, characterized in that the sacrificial rim has a surface width in the range of about 5 percent to about 10 percent of the width of the main rim.

3. The improved tire rim according to claim 1, characterized in that the sacrificial rim has a surface width with a value in the range of about 10 millimeters to about 17 millimeters.

4. The improved tire rim according to claim 1, characterized in that the radial decentering from the transverse profile has a value in a range of about 1.0 millimeter to about 1.5 millimeters.

5. The improved tire rim according to claim 1, characterized in that the width of the notch, of the narrow protruding notch has a value in a range of about 0.2 millimeters to about 1.5 millimeters, so that the sacrificial ridges make contact with the first inner ridges during forward momentum in a straight line.

6. The improved tire rim according to claim 5, characterized in that the protruding notch has a notch depth in a range of values from about 90 percent to about 110 percent of the depth of the notches of the main rim, the depth of the notch measured radially from the rim surface of the main flanges.

7. The improved tire rim according to claim 6, characterized in that the narrow protruding notch has a smooth inner surface to include an enlarged portion at the innermost radial depth of the narrow protruding notch, wherein the enlarged portion of the smooth inner surface It has a radius of at least 1.0 millimeters.

8. The improved tire rim according to claim 1, characterized in that the narrow protruding notches each have an enlarged portion at one end radially inward of the narrow notch and the enlarged portion has a smooth inner curved surface with a radius having a value of at least 1.0 millimeter to reduce the rupture at the end radially inward.

9. The improved tire rim according to claim 1, characterized in that the width of the notch is not greater than about 1.0 millimeter.

10. The improved tire rim according to claim 8, characterized in that the width of the notch has a value in the range of about 0.2 millimeters to about 1.0 millimeter.

11. The improved tire rim according to claim 8, characterized in that the width of the notch has a value in the range of about 0.2 millimeters to about 0.4 millimeters.

12. The improved tire rim according to claim 1, characterized in that the main rims include filtrations or grooves in the side rims of the width of the main rim that extend in a direction from the narrow protruding notch to correspond with the rotation of the tire at a lateral angle of about 15 degrees to 35 degrees from a normal line with respect to the narrow protruding notches and having an angle inclined backward from a normal with respect to the rim surface from zero degrees to about 20 degrees.

13. The improved tire rim according to claim 1, characterized in that the shape factor (SF) of the sacrificial rim (SF) has a value of about 0.2.

14. A tire tire for a heavy-duty truck tire used on a steering axle of a vehicle driven in a long-haul operation, to improve tire wear, the tire tire is characterized in that it comprises: a portion of main rim having at least four circumferential rims including the first inner rims over a width of the main rim separated by the main notches having a depth of the main notch extending around an outer surface of the tire between the lateral edges of the rim width of the main rim, wherein a rim surface of the main rim portion defines a side profile of the main rim; a pair of sacrificial rims, one on each side edge of the rim separated from the first inner rims by a narrow protruding notch adjacent to each of the side edges; each sacrificial rim has a width of the lateral surface in a range of values between about 10 millimeters and about 17 millimeters; the narrow protruding notch has a lateral width in a range of values between about 0.2 millimeters and about 1.5 millimeters and a narrow notch depth between about 90 percent to about 110 percent of the depth of the main notch so that sacrificial ridges make contact with the first inner rims during the straight forward thrust of a loaded tire, wherein the narrow notch has an enlarged portion at one end radially inward of the narrow notch to reduce the break or fracture at the end radially inwardly, and the sacrificial rim has a radially inwardly recessed surface area of the tire defined by a radial runout from a uniform extension of the side profile, the runout has a value in the range of about 0.5 millimeters to about 1.5 millimeters, in where the loads on the truck tire are supported for the most part by the sacrificial rims to relieve stresses on at least the first inner rims and where tire wear of the truck tire is improved.

15. The tire rim according to claim 14, characterized in that the enlarged portion of the narrow protruding notch has an internal smooth curved surface with a radius having a value of at least 1.0 millimeter.

16. The tire rim according to claim 14, characterized in that the lateral width of the narrow protruding notches is not greater than about 1.0 millimeter.

17. The tire rim according to claim 14, characterized in that the first interior rims each include filtrations or grooves located along an axially external edge extending at a lateral angle of approximately 15 degrees to 35 degrees from a normal line to the narrow projecting notch and having an angle inclined backward from a normal to the rim surface of between about 5 degrees and about 15 degrees.

18. The tire rim according to claim 14, characterized in that the sacrificial rim has a shape factor (SF) defined as the depth (DH) of the narrow protruding notch by the slope (M) of an external protruding part of the rim. sacrificial, divided by the width of the lateral surface (C) expressed as SF = (DH) x M / C having a value of approximately 0.2.

19. The tire rim according to claim 15, characterized in that the surface area of the sacrificial rim is a radially inwardly inclined surface from the side profile having the radial runout in said narrow protruding notch and an angle of the slope with a lower value that approximately 15 degrees.

20. The tire rim according to claim 19, characterized in that the angle of the slope is zero degrees providing a constant radial offset from the side profile. SUMMARY OF THE INVENTION The present invention provides a tire with a sacrificial rim (38) for protecting the main rims of the tire rim by retarding the onset of irregular wear and the growth thereof. The improved tire rim comprises a plurality of main rims (32, 34, 36) formed by notches (42, 44) that generally extend circumferentially around an outer surface of the tire to form a width of the main rim, make contact with the support surface. A sacrificial flange (38) is provided to contact the support surface on each side portion of the main flanges. The sacrificial flange (38) is separated from the main flanges (32, 34, 36) by a narrow protruding notch (48) having a notch width not greater than about 1.5 millimeters. The sacrificial flange (38) has a surface width in the range of about 2.5 percent to about 12 percent of the width of the rim. The sacrificial flange (38) has a recess defined by a radial offset from a transverse or lateral profile of the main flanges (32, 34, 36). De-centering has a value in the range of about 0.50 millimeters to about 2.0 millimeters when the tire is new. A form factor is used to define the shape of the sacrificial rim (38) where the shape factor has a value between about 0.10 and 0.50.