MXPA99011978A - Pneumatic tire including belt and circumferential ribs - Google Patents

Abstract

The present invention provides a tire (T) comprising a tread portion having a tread design pattern including circumferentially continuous ribs:lateral ribs (1) and other ribs (2). The tread portion is reinforced by a carcass having at least a ply (5), and by a belt having at least two working plies (61, 62). The working plies (61, 62) extend transversely beneath all the ribs, and extend beyond a limit line (7). The thickness (Ti) of the tread between the radially innermost part of the carcass ply (5) and the radially external surface (10) does not depart from the thickness (Tc) at the middle point by more than 10%. The tire tread portion is molded so that the radially external surface of the lateral and other ribs defines a transverse profile that is substantially flat.

Description

i PNEUMATIC RIM THAT INCLUDES A BELT AND RIMS CIRCUMFERENTIALS Field of the Invention The present invention relates to vehicle tires, and more particularly to heavy duty truck tires specially designed to be used for long distance road transport operations.

Background of the Invention An object of the invention is to provide the driver with a more comfortable driving means. Another object of the invention is to improve the handling of the tire. More specifically, an object of the invention is to solve the problem of deterioration of comfort and handling which in certain circumstances has proved that it will be caused by the tire after it has been in use for a number of miles. It may happen that bearing comfort or handling becomes unacceptable to the driver at a relatively small mileage such that the tire must be removed Rf.032140 long before the end of his normal service life. The problem of the bad evolution of comfort is occurring especially in the tires of the front steering axle, in long-distance services (ie, tires which for the most part do not pass or apply on the road, a couple of Torque as significant as in the driven wheels - not the torque of the driving, the braking operations are not taken into account as a significant part of the service life).

Brief Description of the Invention According to the present invention, the comfort and handling of the tire is solved by providing a tire rim comprising a tread surface portion: having a tread pattern design configuration that includes: a circumferentially continuous rim; lateral, located on each side of the running surface, and including a plurality of other circumferentially continuous ridges located between the two lateral flanges, the flanges lateral have a radially external surface for contact with the road and having lateral projections defining at least partially circumferential continuous notches located between the rims, at least the axially external lateral projection of the lateral rims is terminated radially outward by a joint that separates the surface radially external and the laterally external lateral projection of the side flanges, on each side, a protective cover located axially outwardly from the side flanges, • the portion of the running surface is reinforced by a housing having at least one fold or layer, and reinforced by a belt having at least two folds or working layers that extend transversely beneath the All of the ridges, folds or working layers include parallel cords or strings arranged at an angle in the range of 10 o- 30 °, and the folds or working layers have one end on both sides of the surface rolling, • the end of the folds or working layers is located axially outward from a boundary line that is perpendicular to a reference line of the running surface, the reference line of the running surface is the virtual line parallel to the axis of the road. pneumatic and in contact with the outermost point radially of the radially external surface, • the thickness Tx of the running surface between the radially innermost part of the carcass and the radially external surface, measured perpendicularly to the reference line of the surface of rolling, it does not move away from the thickness Tc at the midpoint by more than 10%, the radially outer surface of the portion of the tread surface of the tire has a radius of transverse curvature greater than 1500 nm, when the tire is mounted on a predefined highlight and it is not inflated.

Description of the Drawings The invention will be understood more clearly from the reading of the following specification and by reference to the accompanying drawings showing two examples of the invention: Figure 1 is a fragmentary plan view of a first variation of a tire characterizing this invention; and Figure 2 is a fragmentary plan view of a second variation of a tire characterizing this invention.

Detailed Description of the Preferred Modality of the Invention A variation of the preferred embodiment of tire T of the present invention is shown in Figure 1 and another variation thereof is shown in Figure 2. Turning to the common characteristics of the two variations, tire T has a portion of the rolling surface that has a design configuration of the running surface. The invention relates to a typical tread surface design configuration that has proven to be suitable for front axle tires used over large distances. This design configuration of the running surface comprises essentially parallel ridges separated by parallel grooves. These ridges Parallels include here, located on each respective side of the running surface, a lateral flange 1 which is circumferentially continuous, ie not divided into a plurality of blocks. This unit of configuration of the basic running surface is repeated laterally, with or without changes of the real-form, so that the running surface includes a plurality of other intermediate ridges 2, located between the two lateral flanges 1 and which are continuous circumferentially. Each side flange 1 and other flanges 2 have a radially outer surface 10. Each of the side flanges 1 and the other flanges 2 are bounded laterally by projections 11, 12 defining them at least in part and two by two continuous circumferential notches 13. In the embodiments illustrating the invention, at least the axially external lateral projection 11 of the lateral rim 1 is terminated radially outwardly by a joint that interconnects the radially external surface 10 and the axially external lateral projection 11. In the described embodiment, the joint is an edge 14. In the two variations of the embodiment, all of the lateral flanges 1 and the other flanges 2 are laterally limited by projections forming an acute angle. The axially external lateral projection 11 of the flange lateral 1 and radially external surface 10 of lateral flange 1, as observed in a radial section similar to the first of Figures 1 and 2, defines an angle that varies between 90 ° and 110 °. In other words, the axially external lateral projection 11 of the lateral flange 1 and the radially outer surface 10 of the lateral flange 1, as seen in a radial section similar to the first of Figures 1 and 2, defines an acute angle. The tire T is reinforced by a carcass comprising at least one fold or layer 5 of the carcass and by a belt. The belt, as shown in the Figures, includes two folds or working layers 61, 62, and a protective layer or fold 63. The means for making the so-called folds or working layers and the fold or protective layer, are well known in the art. Accordingly, no additional details are given in the present description. It is sufficient to remember that the folds or layers of work in general are essentially made of inextensible parallel strings arranged at an angle in the range of 15 ° -30 °, and that a fold to a protective layer is generally a fold or layer which can be more extensible. It is also sufficient to remember that the belt may also include other similar reinforcement means or ropes or cords arranged at an angle of zero with respect to the intermediate circumferential plane of the rim or tire T, also called "crease or reinforcement folds without seams or joints", "having a rope or cords substantially parallel to the circumferential plane of the rim or tire T (a plane perpendicular to the axis of the rim or tire T), the latter reinforcement is especially useful to keep it unchanged after rupture in the shape and properties of the rim or tire The entire side flanges and the other shoulders 1,2 have an external surface radially 10 to make contact with the road Assuming that the road surface is flat (taking into account that the rim or tire T of the invention is designed for applications of great distances, this assumption is close to reality) the external surface radially will be pushed to become flat during rolling According to one aspect of the invention, the belt and more generally the portion of the running surface As a whole, it is designed to achieve a normal tension perpendicular to the radially outer surface 10 on the running surface as regular or uniform as possible in a static condition loaded with the tire T. It could be assumed that the uniform normal stresses will also be experienced during the dynamic rolling of the tire T and that such conditions will improve the comfort and handling of the tire or tire T. In accordance with a feature of the invention, the Belt, more precisely at least the folds or working layers 61, 62 of the belt, extend below all the lateral flanges 1 and the other flanges 2 to provide an equal support thereof. In other words, with reference to the drawings, the ends 610, 620 of the working pleats or layers 61, 62 extend beyond a boundary line (shown with the dotted line). The boundary line 7 is defined by a perpendicular with respect to a reference line 8 of the running surface. The reference line 8 of the running surface, as seen in a radial section of the rim or tire T similar to that shown in Figures 1 and 2, is the imaginary line parallel to the axis of the rim or tire T and in contact with the outermost point radially of the radially external surface 10. A second condition that the limit line 7 has to satisfy, is to pass through the projection 14 of the side flange 1. It should be noted that the portion of the running surface of the rim or tire T is molded so that the radially outer surface 10 of the side flanges and the other flanges define a transverse profile which is close to a cylinder when the tire T is mounted on a predefined and uninflated shoulder. The radius of transverse curvature R is in the range of 1,500 mm to an infinite value. Advantageously, the radius of transverse curvature is greater than 5,000 mm. For example, the two variations show a radius of transverse curvature R that reaches 20,000 mm. With reference to the drawings, it is noted that the thickness Tx of the running surface is indicated at different locations: the thickness Tx at the axially external boundary of the side rim 1, the thickness T2 for the respective adjacent adjacent rim 2, and the thickness Tc in the middle part of the rim or tire T (the thickness or thickness measured in the middle circumferential plane, ie the plane perpendicular to the axis of rotation of the rim or tire and passing through the center of its running surface ). The thickness or thickness Ti is measured between the radially innermost part of the fold or layer 5 of the shell and the radially outer surface 10. The thickness T_. it is measured perpendicularly with respect to the reference line 8 of the rim or tire. The portion of the surface of rolling measured by the thickness or thickness Tx includes elements of reinforcement of the belt, the compounds of the rubber and the fold or layer of the casing. If the housing includes more than a single fold of the housing, the thickness or thickness is measured from the innermost part radially of the radially innermost fold or layer. A reference described generally as "the radially innermost part of the housing" is hereby established. According to another feature of the invention, the thickness or thickness T ±, at any point between the middle part of the tire tread surface and the radially outermost part of the side rim 1, does not deviate from the thickness or thickness Tc in the intermediate point by more than 10%, and preferably by no more than 8%. In any case, the thickness is greater than 20 m, as is the case of a tire or tire T for a heavy duty truck. The following table is an example of the thickness T ± taken on a rim or tire T according to the invention.

In this tire or tire T, the thickness difference is (28.6-27) / (27) = 5.9%, consequently less than 8%. The onset of unacceptable comfort or unacceptable handling, or the speed of deterioration of the same if any, is therefore maintained within limits that are considerably more compatible with the normal service life of the rim or tire., whereby the removal of the rim or tire T is avoided long before the height of the rims has decreased above the predetermined wear limit. On each side of the rim or tire, a protective layer is located axially outwardly from the side flanges. The two examples illustrating the invention differ by the modality of the cover. The cover on Figure 1 is a narrow projecting ridge 3. The standard tread rubber materials can be used for the projecting ridge 3 as well as for the side rims 1 and the other rims 2. The projecting ridge 3 is recessed laterally of the side flange 1 by a narrow notch 31. In other words, the surface 30 of the protruding flange 3 is recessed with respect to the radially outer surface 10 of the side flange 1. According to the need to protect the belt According to the invention, a preferred width of the protruding flange 3 is in a range of about 10 millimeters to about 20 millimeters. The dimensions and geometry of the protruding flange 3 are selected so that, during normal operation of the rim or tire T, they experience different stresses than the side flanges 1 and the other flanges 2. This feature helps maintain a sharp protrusion 14 on the lateral flanges 1. In the particular geometry of the protruding flange 3, the radial height of the protruding flange 3 is below the external surface radially 10 by a distance in the range of 1 mm to 2 mm. Figure 2 shows another cover which is not a wear part of the running surface and has no contribution to sustain the load. Its function is only to protect the ends 610, 620 of the working folds or layers 61, 62 and the end 630 of the fold or protective layer 63. The protective layer is a rubber product 4 having an inner end axially joined with the part bottom of the lateral projection 11 axially external. In other words, the radially outer surface 40 of the rubber product 4 is approximately uniform with the lower part of the notches 13. This variation can be used to improve the cooling of the protruding part if the protruding flange aid seems not to be needed. To be more general, the protective cover could have any radial height between the limits described by the above variations illustrating the invention. The protective cover could still be made with the outer surface radially 10, and in this case another rubber material could be used than one of the main part of the running surface; the rubber material of the protective cover could ideally be less hysterical than the rubber material of the side flanges 1 and the other flanges 2. In the two variations of the preferred embodiment, the housing is a radial housing. The tire or tire T is designed to be mounted on a shoulder, the shape and dimensions of which are defined by well-established standards (See for example "The Tire and Rim Association, Inc." or "The European Tire &Rim Technical Organization "). In accordance with the well-known way of designing tires or tires, a tire or tire T of a preselected size is designed to work on one or a pair of the shoulder sizes selected among the standards mentioned above. The tire or tire T is also designed to work at a so-called "nominal inflation pressure". In the embodiments described, the housing is designed to assume, if the rim or tire T is mounted on the specific shoulder and inflated to the nominal inflation pressure, a form of natural balance in the side walls. In the area of the running surface, the carcass is stuck on the belt and works as a unit with the folds or layers of work; the casing tends to assume a cylindrical shape. In the projecting portion, beyond the protective cover, the housing is connected to that part which has a cylindrical shape (in the portion of the running surface) and to that part which has a natural form of balance (in the side walls) in as progressive and smooth a way as possible.

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 described the invention as above, property is claimed as contained in the following

Claims (17)

1. A rim for large truck, heavy load, with radial belts, pneumatic, having a portion of rolling surface with a configuration of selected tread surface and a delayed start of unacceptable comfort and handling, the rim is characterized by: the portion of the running surface has a circumferentially extending lateral shoulder on each outer side of the running surface portion, a plurality of circumferentially extending intermediate shoulders located between the side shoulders, the lateral and intermediate shoulders define a outer surface extending circumferentially and a plurality of notches separating some adjacent notches; the outer boundaries of at least the lateral projections of the lateral flanges form a junction with the circumferentially extending outer surface; a carcass and a belt with at least a pair of folds or working layers that reinforce the portion of the running surface, the folds or working layers extend transversely under the side flanges with opposite end portions thereof which are located outside the portion. to the running surface; on each side of ur. semicircumferential plane, a protective cover formed axially outwardly of the respective lateral flange and the end portions and radially outwardly from each of the end portions of the folds or working layers; a reference line of the running surface extending parallel to the axis of the rim and in lateral contact with the outer surface, a first boundary line extending perpendicular to the reference line of the running surface and through the junction, a second boundary line extending perpendicular with respect to the reference line of the running surface and along the semi-circumferential plane; the running surface has a thickness measured between the radially innermost part of the housing and the external surface along the first and second boundary lines, the thickness is constant within 10% between the boundary lines; and, the outer surface has a transverse radius of curvature greater than 2500 mm when the The tire is mounted on the predefined and inflated shoulder.

2. The compliance rim cor. Claim 1, characterized in that each of the working folds or layers includes cords and the cords are parallel and arranged at an angle with respect to the circumferential direction of between 10 ° and 30 °.

3. The rim according to claim 1, characterized in that the radius of curvature is greater than 5000 mm.

4. The rim according to claim 1, characterized in that the thickness is greater than 20 mm.

5. The rim according to claim 1, characterized in that each of the protective covers includes a protruding flange having a height radially below the reference line of the running surface by between about 1 mm to 2 mm. 1 < ?

6. The compliance rim cor. claim 1, characterized in that each of the protective covers extends axially outwardly from the outer lateral surface of the lateral flanges beyond the end portions of the folds or working layers.

7. The rim according to claim 1, characterized in that the lateral lateral projections of the lateral flanges and the external surface define an angle between 90 ° and 110 ° in the joint.

8. The rim according to claim 1, characterized in that the joint is angular.

9. The rim according to claim 1, characterized in that the rubber material forming each of the protective covers is less hysterical than the rubber material that forms the remainder of the portion of the running surface.10. The rim according to claim 1, characterized in that each of the

Protective covers include a radially outer surface, the outer radial surface of the protective cover is aligned with the bottom portions of the notches.

11. A pneumatic tire, characterized in that it has a portion of the tread surface with a design configuration of the selected tread surface: the tread portion has a circumferentially extending lateral ridge on each outer side of the tread portion. rolling surface, a plurality of circumferentially extending intermediate flanges, located between the lateral flanges, the lateral and intermediate flanges defining a circumferentially extending outer surface and a plurality of notches that are spaced apart from some adjacent flanges; the outer limits of at least the lateral lateral protrusions of the lateral flanges forming a junction with the circumferentially extending outer surface; a carcass and a belt with at least a pair of layers or work pleats that reinforce the portion of the running surface, the folds or layers of work that extends transversely beneath the side ridges with the opposite end portions thereof which are located outwardly from the portion of the running surface; a reference line of the running surface extending parallel from the axis of the rim, a first boundary line extending perpendicular to the reference line of the running surface line and through the joint, a second boundary line extending perpendicular to the reference line of the running surface and along a semi-circumferential plane; the rolling surface has a thickness of not less than 20 mm measured between a radially innermost part of the housing and the external surface along the first and second limit lines, the thickness is constant within 8% and 10% between the limit lines; and, the outer surface has a radius of transverse curvature of about 5,000 mm; wherein, the outer surface is contacted by the reference line of the running surface.

12. The compliance rim cor. claim 11, characterized in that it includes each side of a semi-circumferential plane including a protective cover formed axially outwardly of ur. respective lateral flange and the end portions of the working folds or layers, and formed radially outwardly from each of the end portions of the folds or working layers.

13. The rim according to claim 12, characterized in that each of the protective covers includes a protruding rim having a height radially below the outer surface by between about 1 mm to 2 rnm.

14. The rim according to claim 12, characterized in that each of the protective covers extends axially outwards from the lateral lateral protrusions of the lateral rims beyond the end portions of the folds or working layers.

15. The rim according to claim 12, characterized in that the rubber material forming each of the protective covers is less hysterical than the mater: • _ ae cau; aaí reste de la Dorciór. of the suser icxe ae rcaaaur

16, rim A; onformiaaa claim 12, characterized in that each of the protective covers includes an external surface radially, the external surface radially of the protective cover is generally aligned with the lower parts of the notches.

17. The rim according to claim 11, characterized in that the lateral lateral projections of the lateral flanges and the external surface define an angle between 90 ° and 110 ° in the joint.