Tread profile of a pneumatic vehicle tire with an indicator for regrooving the profile

Abstract

A regroovable tread profile of a pneumatic vehicle tire includes a regrooving indicator formed with an additional indent in the base of the depression in the form of a blind hole lying transversely in relation to the main direction of extent (U) of the groove and having a length of extent (A.sub.2) and an indent depth (B), where (B) is formed such that B<A.sub.2 and B<A.sub.1 and B<L and with a depth of extent (T.sub.2) where T.sub.2>T.sub.1, which is measured starting from the groove base inward in the radial direction (R) to the base bounding the indent radially inwardly. The depth of extent (T.sub.1) forms the measure for the minimum regrooving depth and the depth of extent (T.sub.2) forms the measure for the maximum regrooving depth.

Claims

1. A tread profile of a pneumatic vehicle tire defining a radial direction (R), the tread profile comprising: a regroovable tread profile having radially raised profile elements and defining at least one groove which separates two mutually adjacent ones of said raised profile elements; said at least one groove defining a main extension direction (U) and having a groove base delimiting said at least one groove inwardly in the radial direction (R); said at least one groove having at least one regrooving indicator formed in said corresponding groove base; said at least one regrooving indicator including a blind-hole shaped depression having an intercept contour and a depression base; said blind-hole shaped depression with said intercept contour having an extension length (L) measured in said main extension direction (U) and an extension width (A.sub.1) measured transverse to said main extension direction (U); said blind-hole shaped depression being, in the radial direction (R), inwardly delimited by said depression base; said blind-hole shaped depression having an extension depth (T.sub.1) measured inwardly in the radial direction (R) starting from said groove base to said depression base; said extension depth (T.sub.1) being configured to indicate a regrooving depth; said at least one regrooving indicator further including an indent in said depression base of said blind-hole shaped depression and said indent being orientated transverse to said main extension direction (U); said indent having an indent base radially inwardly delimiting said indent; said indent further having an indent extension length (A.sub.2) measured transverse to said main extension direction (U), an indent width (B) measured in said main extension direction (U), and an indent depth (T.sub.2) measured in the radial direction (R) starting from said groove base and continuing to said indent base; said indent width (B) being less than said indent extension length (A.sub.2) and said indent width (B) being less than said extension length (L); said indent depth (T.sub.2) being greater than said extension depth (T.sub.2); said extension depth (T.sub.2) being configured to form a measure for a minimum regrooving depth; said indent depth (T.sub.2) being configured to form a measure for a maximum regrooving depth; and, wherein said indent extension length (A.sub.2) is less than said extension width (A.sub.1).

2. The tread profile of claim 1, wherein: said extension length (L) of said blind-hole shaped depression lies in a range of 2 mmL5 mm; and, said extension width (A.sub.1) lies in a range of 2 mmA.sub.15 mm.

3. The tread profile of claim 1, wherein: said extension depth (T.sub.1) lies in a range of 0.5 mmT.sub.15 mm; and, said indent depth (T.sub.2) lies in a range of 1.5 mmT.sub.26 mm.

4. The tread profile of claim 1, wherein said extension depth (T.sub.1) and said indent depth (T.sub.2) have a relationship T.sub.2=(T.sub.2+1 mm).

5. The tread profile of claim 1, wherein said indent width (B) lies in a range of 0.5 mmB1 mm.

6. The tread profile of claim 1, wherein: said at least one groove has a first groove width (B.sub.RG) measured at said groove base transverse to said main extension direction (U); said indent extension length (A.sub.2) is less than said first groove width (B.sub.RG); the tread profile defines an outer circumferential surface; said at least one groove further has a second groove width (B.sub.RO) measured at said outer circumferential surface transverse to said main extension direction (U); and, said indent extension length (A.sub.2) is less than said second groove width (B.sub.RO).

7. The tread profile of claim 1, wherein said blind-hole shaped depression is formed in said groove base of said at least one groove having one of a circular, elliptical, and oval section contour.

8. The tread profile of claim 1, wherein: said blind-hole shaped depression is cylinder shaped and defines a cylinder axis substantially extending in the radial direction; said depression base forms a first end surface of the cylinder; and, said cylinder has a second end surface formed by the intercept contour with said groove base.

9. The tread profile of claim 1, wherein: said blind-hole shaped depression has a truncated cone shape and defines a cone axis substantially extending in the radial direction (R); said depression base forms a first end face of said cone; said cone has a second end face surrounded by the intercept contour with said groove base; and, said first end face is smaller than said second end face.

10. The tread profile of claim 1, wherein: said groove base has a raised portion forming a wear indicator (TWI); and, said at least one regrooving indicator is formed in said raised portion.

11. The tread profile of claim 1, wherein said at least one groove has a groove depth T.sub.P lying in a range of 10 mmT.sub.P30 mm.

12. The tread profile of claim 1, wherein said at least one groove in a circumferential groove defining a circumference and having a plurality of said at least one regrooving indicators distributed over said circumference.

13. The tread profile of claim 1, wherein the pneumatic vehicle tire is configured for a commercial vehicle.

14. A tread profile of a pneumatic vehicle tire defining a radial direction (R), the tread profile comprising: a regroovable tread profile having radially raised profile elements and defining grooves which separate each two mutually adjacent ones of said raised profile elements; said grooves defining a main extension direction (U) and having respective groove bases delimiting said grooves inwardly in the radial direction (R); each of said groove bases having at least one regrooving indicator formed therein; said at least one regrooving indicator including a blind-hole shaped depression having an intercept contour and a depression base; said blind-hole shaped depression with said intercept contour having an extension length (L) measured in said main extension direction (U) and an extension width (A.sub.1) measured transverse to said main extension direction (U); said blind-hole shaped depression being, in the radial direction (R), inwardly delimited by said depression base; said blind-hole shaped depressionhaving an extension depth (T.sub.1) measured inwardly in the radial direction (R) starting from said groove base to said depression base; said extension depth (T.sub.1) being configured to indicate a regrooving depth; said at least one regrooving indicator further including an indent in said depression base of said blind-hole shaped depression and said indent being orientated transverse to said main extension direction (U); said indent having an indent base radially inwardly delimiting said indent; said indent further having an indent extension length (A.sub.2) measured transverse to said main extension direction (U), an indent width (B) measured in said main extension direction (U), and an indent depth (T.sub.2) measured in the radial direction (R) starting from said groove base and continuing to said indent base; said indent width (B) being less than said indent extension length (A.sub.2) and said indent width (B) being less than said extension length (L); said indent depth (T.sub.2) being greater than said extension depth (T.sub.1); said extension depth (T.sub.1) being configured to form a measure for a minimum regrooving depth; said indent depth (T.sub.2) being configured to form a measure for a maximum regrooving depth; and, wherein said indent extension width (A.sub.2) is less than said extension width (A.sub.1).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be described with reference to the drawings wherein:

(2) FIG. 1 shows a segment of the circumference of a regroovable tread profile of a pneumatic vehicle tire for commercial vehicles;

(3) FIG. 2 is an enlarged view of a circumferential groove of the tread profile of FIG. 1 with a regrooving indicator in plan view of the tread profile;

(4) FIG. 3 is a sectioned view of the circumferential groove with a regrooving indicator in accordance with section of FIG. 2;

(5) FIG. 4 is a sectioned view of the circumferential groove with a regrooving indicator in accordance with section IV-IV of FIG. 2;

(6) FIG. 5 shows the circumferential groove with a regrooving indicator in an alternative embodiment in plan view;

(7) FIG. 6 is a sectioned view of the circumferential groove in accordance with section VI-VI of FIG. 5;

(8) FIG. 7 is a sectioned view of the circumferential groove in accordance with section VII-VII of FIG. 5; and,

(9) FIG. 8 shows a circumferential groove and a regrooving indicator in an alternative embodiment, in which the regrooving indicator is positioned in the position of an abrasion indicator, the view being similar to that of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

(10) FIGS. 1 to 4 show a regroovable tread profile of a pneumatic vehicle tire for commercial vehicle tires, in which radially raised profile strips 1 extending over the entire circumference of the pneumatic vehicle tire and aligned in the circumferential direction U are arranged adjacent to one another in the axial direction A of the pneumatic vehicle tire, wherein two axially adjacent profile strips 1 in each case are spaced apart from one another axially by a circumferential groove 2 aligned in the circumferential direction U of the pneumatic vehicle tire and extending over the entire circumference of the pneumatic vehicle tire. The profile strips 1 are each delimited in the radially outward direction R by a radially outer surface 3, which forms the bottom contact surface, forming the circumferential surface of the tire. The circumferential grooves 2 are delimited in the radially inward direction R by a groove base 4 which extends over the entire circumference of the pneumatic vehicle tire and is aligned in the circumferential direction U. The circumferential grooves 2 are each delimited in the axial direction A of the pneumatic vehicle tire on one side by a flank 5 of one profile strip 1 delimited by the circumferential groove 2 and on the other side by a flank 6 of the other profile strip 1 delimited by the circumferential groove 2. The flanks 5 and 6 each extend from the inside outward in the radial direction R, starting from the groove base 4, as far as the radially outer surface 3 of the respective profile strip 1 delimited by the flank 5 or 6, and in the process form the two groove walls of the circumferential groove 2.

(11) At the groove base 4, the circumferential grooves 2 are each formed with a width B.sub.RG of the groove base 4, measured transversely to the principal direction of extent of the respective circumferential groove 2 and thus in the axial direction A of the pneumatic vehicle tire, and, in the radially outer circumferential surface, are formed with a groove width B.sub.RO. The width at the radially outer surface B.sub.RO is in each case the measure of the spacing between the intersection of the flank 5 with the radially outer surface 3 of the profile strip 1 delimiting the circumferential groove 2 on one side, measured in the axial direction A in the cross-sectional planes containing the tire axis, and the intersection of the flank 6 with the radially outer surface 3 of the profile strip 1 delimiting the circumferential groove 2 on the other side. The groove widths B.sub.RG and B.sub.RO are governed by B.sub.RO>B.sub.RG.

(12) The groove base 4 is formed with a rectilinear contour profile in the cross-sectional planes perpendicular to the direction of longitudinal extent of the circumferential grooves 2 and thus in the cross-sectional planes containing the tire axis in the illustrative embodiment shown.

(13) The circumferential groove 2 is in each case formed with a depth P.sub.T which corresponds to the profile depth of the tire and which is measured inward in the radial direction R as far as the groove base 4, starting from the radially outer surface 3. The profile depth P.sub.T is formed so that 10 mmP.sub.T30 mm, for example, so that P.sub.T=15 mm.

(14) A plurality of regrooving indicators 7 is formed in the groove base 4 of the circumferential grooves 2, in each case in a manner distributed over the circumference of the circumferential groove 2. For example, two, three, four, five or six regrooving indicators are formed in a circumferential groove in a manner distributed over the circumference of the circumferential groove 2. In a special embodiment, just a single regrooving indicator 7 is formed in a circumferential groove 2.

(15) Hereas indicated in FIGS. 2 to 4the regrooving indicator 7 is in each case formed with a depression 8 in the form of a blind hole and with an additional indent 9. The depression 8 in the form of a blind hole is cylindrical with a cylindrical circumferential surface and with a cylinder axis which is aligned substantially in the radial direction R of the pneumatic vehicle tire, and is delimited in the radially inward direction by a depression base 10, which forms one end face of the cylindrical shape. The other end face of the cylindrical shape is formed by the intersection contour of the cylindrical circumferential surface with the groove base 4. The cylinder is formed with a cylinder diameter D. The depression 8 thus extends along the principal direction of extent of the circumferential groove 2 and thusin the illustrative embodiment shownin the circumferential direction U over a length L of extent and transversely to the principal direction of extent of the circumferential groove and thusin the illustrative embodiment shownin the axial direction A of the pneumatic vehicle tire over a width A.sub.1 of extent, wherein the following applies for the length L of extent and the width A.sub.1 of extent in the case of the illustrative cylinder with a cylindrical circumferential surface in the form of a circular cylinder: L=A.sub.1=D.

(16) Starting from the groove base 4, the depression 8 is formed in the radially inward direction R with a depth T.sub.1, which forms the radial spacing from the groove base 4 to the depression base 10. The regrooving indicator 7 is additionally formed via an indent 9, which extends in the groove base 10 transversely to the principal direction of extent of the circumferential groove 2and thus, in the illustrative embodiment shown, in the axial direction A of the pneumatic vehicle tirewith a length A.sub.2 of extent and with an indent width B, measured transversely thereto in the principal direction of extent of the circumferential groove 2and thus in the circumferential direction Uwhere B is formed so that B<A.sub.2, B<A.sub.1 and B<L. The indent 9 is formed with a constant width B in the radially inward direction R as far as a depth T.sub.2, at which the indent 9 is delimited in the radially inward direction by an indent base 11. The indent depth T.sub.2 is the spacing, measured in the radial direction R, between the groove base 4 and the indent base 11. The depths T.sub.1 and T.sub.2 are formed so that T.sub.2>T.sub.1.

(17) The indent depth T.sub.1 is formed so that 0.5 mmT.sub.15 mm. The indent depth T.sub.2 is formed so that 1.5 mmT.sub.26 mm. Here, the depths T.sub.1 and T.sub.2 are chosen so that T.sub.2=(T.sub.1+1 mm). For example, T.sub.2=5 mm and T.sub.1=4 mm.

(18) The length L of extent of the depression 8 in the form of a blind hole is formed so that 2 mmL5 mm. The width A.sub.1 of extent is formed so that 2 mmA.sub.15 mm. In the illustrative embodiment shown, in which the depression 8 is configured as a circular-cylindrical depression in the form of a blind hole with the diameter D, the diameter D is formed so that 2 mmD5 mm. For example, L=A.sub.1=D=4 mm is chosen.

(19) The width B of the indent 9 is formed so that 0.5 mmB1 mm. The length A.sub.2 of extent of the indent 9 is formed so that B.sub.RO>A.sub.2>B.sub.RG.

(20) In the illustrative embodiments shown in FIGS. 2 to 4, the indent 9 is formed with a length A.sub.2 of extent which is less than the width A.sub.1 of extent of the depression. In another illustrative embodiment (not shown), the length A.sub.2 of extent is equal to the width A.sub.1 of extent and, on both sides, ends at the cylinder contour of the depression 8. In both of these embodiments, the depression base 10 forms the indication of the regrooving indicator 7 for the minimum regrooving depth that has not yet been reached. The indent base 11 forms the indication for the maximum regrooving depth that has not yet been reached. FIGS. 5 to 7 show an alternative illustrative embodiment, in which the regrooving indicator 7 is formed with the depression 8 and the indent 9 in the manner described with reference to FIGS. 1 to 4, but the length A.sub.2 of extent of the indent 9 is formed so that A.sub.2>A.sub.1 and the indent 9 extends beyond the circular-cylindrical contour of the depression 8 on both sides along its direction of extent. In the illustrative embodiment shown, the length A.sub.2 of extent is formed so that B.sub.RO>A.sub.2>B.sub.RG, wherein the indent 9 forms an extension beyond the circular-cylindrical contour of the depression 8 as far as the axial region of extent of the flanks 5 and 6 and ends there. In this illustrative embodiment, the length A.sub.2 of extent provides additional information on the regrooving width of the circumferential groove to be recut. The tool used for regrooving is chosen so that it allows for the indicated width A.sub.2 of the circumferential groove to be recut and recuts a groove of width A.sub.2.

(21) In an illustrative embodiment which is not shown, the depression 8 illustrated in FIGS. 1 to 4 and in FIGS. 5 to 7 is configured as a cylindrical depression in the form of a blind hole which has an elliptical or oval cross section of the cylinder circumferential surface thereof. In this case, the longer of the two principal axes of extent of the oval or elliptical contour is aligned in the principal direction of extent of the circumferential groove 2 and thus specifies the length L of extent of the depression 8. The shorter of the two principal axes of extent of the oval or elliptical contour is aligned in the transverse direction of the circumferential groove 2 and thus in the axial direction A of the pneumatic vehicle tire. The length of extent thereof thus forms the length A.sub.1 of extent of the depression 8, wherein in this case L and A.sub.1 are configured so that L>A.sub.1.

(22) In an embodiment which is not shown, the depression 8 in the form of a blind hole is configured as a frustoconical depression, wherein the cone axis, like the cylinder axis in the embodiments illustrated, is configured to extend substantially in the radial direction R and the circumferential surface of the frustocone tapers in a constant manner, from the groove base 4 to the depression base 10. For example, the circumferential surface of the frustocone is circular in the cross sections perpendicular to the cone axis thereof. At the groove base 4, the circumferential surface of the frustocone has a larger diameter than at the depression base 10.

(23) FIG. 8 shows an alternative arrangement of the regrooving indicator 7. In this illustrative embodiment, a plurality of abrasion indicators (TWI) 12 of known type is formed in a manner distributed over the circumference of the pneumatic vehicle tire, rising radially outward as raised portions extending in the radial direction R of the pneumatic vehicle tire from the groove base 4 over a height T.sub.3 of extent, between the profile strips 1 delimiting the circumferential groove 2, and extending over the entire width of the circumferential groove 2. In a known manner, the abrasion indicator 12 (TWI) is formed so as to be delimited at the distance T.sub.3 from the groove base 4 in a radially outward direction by a virtually flat radially outer surface 13, which indicates the maximum permissible abrasion of the tire. As illustrated in FIG. 8, the regrooving indicator 7 is formed with its depression 8 and the indent 9 centrally within the length of circumferential extent of the outer surface 13 of the raised portion forming the abrasion indicator 12 when viewed in the circumferential direction U of the tire. The further configuration of the regrooving indicator 7 is designed as shown or described in the embodiments illustrated or described with reference to FIGS. 1 to 4 and FIGS. 5 to 7. By virtue of the integrated design of the regrooving indicator 7 and of the abrasion indicator 12, the minimum regrooving depth is additionally indicated by the depression base 10 and the maximum regrooving depth by the indent base 11 at this position. In one embodiment, the regrooving indicator 7 is formed as illustrated in FIGS. 1 to 4. In another embodiment, which is illustrated in FIG. 8, the regrooving indicator 7 is formed as illustrated in FIGS. 5 to 7. In this case, the common regrooving indicator 7, which is embodied so as to integrate the abrasion indicator 12 as well, additionally indicates the regrooving width of the circumferential groove to be recut via the special configuration of the indent length A.sub.2.

(24) In the circumferential direction U of the pneumatic vehicle tire, the abrasion indicator 12 is formed with a length E of extent, where 5LE2L.

(25) In the illustrative embodiment shown in FIG. 1, the profile strips 1 are each configured as circumferential ribs extending over the circumference of the pneumatic vehicle tire. In another embodiment (not shown), the profile strips 1 are configured as profile block rows of known type which extend over the entire circumference of the pneumatic vehicle tire and are formed by profile block elements arranged in series in the circumferential direction U of the pneumatic vehicle tire and in each case spaced apart from one another by transverse grooves. In another embodiment (not shown), some of the profile strips are configured as circumferential ribs and some of the profile strips are configured as profile block rows.

(26) As shown in FIGS. 3 and 4, in FIGS. 6 and 7 and in FIG. 8, in a partially exaggerated way, the transitions between the depression base 10 and the cylindrical circumferential surface of the depression 8 in the form of a blind hole and between the cylindrical circumferential surface of the depression 8 in the form of a blind hole and the groove base 4 are of rounded design.

(27) To determine the extent of the depression 8 at the groove base 4 and at the depression base 10, the extended intersection of the circumferential surface of the depression 8 with the groove base 4 and with the depression base 10 is used. In the case of a circular-cylindrical circumferential surface, the diameter D is constant along the entire extent of the cylinder along the cylinder axis thereof and is used as a measure A.sub.1 or L.

(28) It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.

LIST OF REFERENCE SIGNS

(29) (Part of the Description)

(30) 1 profile strip 2 circumferential groove 3 radially outer surface forming the circumferential surface 4 groove base 5 flank 6 flank 7 regrooving indicator 8 depression in the form of a blind hole 9 indent 10 depression base 11 indent base 12 abrasion indicator (TWI) 13 surface