An on/off road tread for a tire - European Patent Office

Europäisches Patentamt
(19)
European Patent Office
*EP001093939B1*
Office européen des brevets
(11)
EP 1 093 939 B1
EUROPEAN PATENT SPECIFICATION
(12)
(45) Date of publication and mention
(51) Int Cl.7:
of the grant of the patent:
07.09.2005 Bulletin 2005/36
B60C 11/04, B60C 11/11,
B60C 11/13
// B60C107:02, B60C107:00
(21) Application number: 00121989.8
(22) Date of filing: 10.10.2000
(54) An on/off road tread for a tire
Reifenlauffläche für Strassen/geländegängige Fahrzeuge
Profil de bandage pneumatique pour route ou tout-terrain
(84) Designated Contracting States:
(72) Inventor: Maxwell, Paul Bryan
DE FR GB IT
Kent, OH 44240 (US)
(30) Priority: 20.10.1999 US 421610
(74) Representative: Kutsch, Bernd
Goodyear S.A.
Patent Department
7750 Colmar-Berg (LU)
(43) Date of publication of application:
25.04.2001 Bulletin 2001/17
(73) Proprietor: THE GOODYEAR TIRE & RUBBER
EP 1 093 939 B1
COMPANY
Ohio 44316-0001 (US)
(56) References cited:
WO-A-99/52720
FR-A- 2 415 550
FR-A- 1 511 630
US-A- 4 481 991
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give
notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in
a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art.
99(1) European Patent Convention).
Printed by Jouve, 75001 PARIS (FR)
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EP 1 093 939 B1
Description
Technical Field
[0001] This invention relates to a radial pneumatic
light truck or automobile tire. More particularly, the tire
has a tread designed for both on or off road applications.
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Background of the Invention
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[0002] With the continuing rise in popularity of light
trucks, vans and four-wheel drive sport utility vehicles,
there exists a need to provide tires that have the ability
to be driven on paved roads without excessive noise yet
also to be capable of being driven in heavy snow or off
paved roads in soft sand or muddy soil. Often these tires
will be driven in flooded or wet roadway conditions. As
an added condition, these multipurpose traction demands for the tire must be coupled with excellent tread
wear.
[0003] Historically, tires have been able to meet one
or two of the above-referenced design requirements but
usually at the sacrifice of the other design features.
[0004] Snow tires and off road tires could achieve
good traction usually by opening the tread pattern and
providing large block type tread elements. These tires
generally were very noisy and had poor tread wear when
driven at highway speeds on paved roads. The WRANGLER MT® disclosed in US-A- 4,823,855 is an example
of the aggressive style tread pattern needed for aggressive off road applications.
[0005] A latter developed asymmetric non-directional
tire was developed for the light truck and sport utility vehicles called the WRANGLER GSA®. This tire employed a unique triple traction feature that provides excellent uniform wear across the tread pattern regardless
of the wheel position. The tire has good noise, and more
than adequate traction in a variety of conditions such as
snow, off road, and on road wet or dry. The tread pattern
disclosed in US-A- 5,415,215 was one of the first truly
multipurpose tires for these types of vehicles. The
WRANGLER GSA® tire has been commercially very
successful.
[0006] From that tire, a superior wet traction tire was
developed employing two wide aquachannels in combination with the triple traction feature. The tire has been
entitled the WRANGLER AQUATRED® and it is disclosed in US-A-5,658,404. This tire demonstrated that
deep water traction could be enhanced without sacrificing the wear and other performance features of the original WRANGLER GSA® tire.
[0007] The WRANGLER AQUATRED® demonstrated that while the all around performance of these light
truck and sport utility vehicle tires must be very good,
some drivers still have special needs or concerns requiring the more specialized type tire performance in one or
more feature.
[0008] There has been a continual trade-off in at-
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tempting to increase the aggressive off road and snow
tractive performance of the these tires while maintaining
the tread wear durability and good ride performance
constraints.
[0009] The invention disclosed in this patent application teaches a novel tread that is both good riding and
long wearing while also achieving excellent off road traction.
[0010] FR-A- 1 511 630, corresponding with the preamble of claim 1, discloses a winter tire with a tread having a plurality of traction elements arranged in three circumferentially repeating rows. The middle row comprises chevron-shaped elements having a truncated apex.
The shoulder rows each have a pair of laterally extending shoulder lugs. One shoulder lug has a narrow axially
inner end directed to the truncated apex of the chevron,
and the other shoulder lug has an enlarged axially inner
end extending toward and adjacent to the truncated
apex.
[0011] US-A- 4 481 991 describes a tread configuration with several peripheral rows of essentially V-shaped
blocks with the points of successive blocks alternately
pointing in opposite directions transverse to the circumferential direction of the tire.
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Disclosure of the Invention
Summary of the Invention
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[0012] A tread (20) for a pneumatic tire (10) is disclosed. The tread (20) has a plurality of traction elements (40, 42, 44) arranged in three circumferentially
extending rows (2, 4, 6); a middle row (4), a first shoulder
row (2), and a second shoulder row (6).
[0013] The middle row (4) has a plurality of chevronshaped traction elements (42) having a truncated apex
(43). Each chevron-shaped traction element (42) alternates in orientation circumferentially around the tread
(20).
[0014] Each shoulder row (2, 6) has a pair of laterally
extending shoulder traction elements (40, 44). The traction elements (40) are a first laterally extending shoulder
lug (40) having an elongated length relative to the width.
The first laterally extending shoulder lug (40) has a narrow axially inner end (41) circumferentially aligned with
the truncated apex (43) of the chevron-shaped traction
element (42) and extending toward and adjacent to an
open end (50) of the chevron-shaped traction element
(42). The narrow end (41) of the laterally extending
shoulder lug (40) slopes radially inwardly to the inner
tread surface (22) and extends axially about halfway or
at least halfway into the open end (50) of the chevronshaped traction element (42).
[0015] The traction elements (44) are a second laterally extending shoulder lug (44) having a elongated
length relative to the width. The second laterally extending lug (44) has an enlarged axially inner end (45). The
enlarged axially inner end (45) is circumferentially
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aligned with and extends toward and is adjacent the
truncated apex (43) of chevron-shaped traction element. Preferably, the enlarged axially inner end (45) has
a laterally extending semi-blind groove (60) bisecting
the enlarged axially inner end (45).
[0016] Preferably, the first shoulder row (2) and the
second shoulder row (6) have the laterally extending
shoulder lugs (40, 44) circumferentially alternating
around the tread (20) with the lugs (40) of the first shoulder row (2) being circumferentially offset with the lugs
(40) of the second shoulder row (6). The lugs (44) are
circumferentially aligned with the lugs (40) of the opposite shoulder row (2, 6). Most preferably, the lugs (40,
44) and the chevron-shaped traction element (42) are
circumferentially aligned such that a line (70) bisecting
each aligned lug (40, 44) and chevron-shaped traction
element (42) is laterally extending.
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Brief Description of the Drawings
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[0017]
FIGURE 1 is a perspective view of the tire according
to a preferred embodiment of the invention.
FIGURE 2 is a plan view of the tire of FIGURE 1.
FIGURE 3 is a side view of the tire of FIGURE 1.
FIGURE 4 is an enlarged fragmentary view of the
tire of FIGURE 2.
FIGURE 5 is an enlarged fragmentary plan view of
the tread of FIGURE 2.
FIGURE 6 is a cross-sectional view of the tire taken
along line 6-6 of FIGURE 5.
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Definitions
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[0018] For ease of understanding this disclosure the
following terms are disclosed:
"Aspect ratio" of the tire means the ratio of its section height (SH) to its section width (SW) multiplied
by 100% for expression as a percentage.
"Asymmetric tread" means a tread that has a tread
pattern not symmetrical about the centerplane or
equatorial plane EP of the tire.
"Circumferential" means lines or directions extending along the perimeter of the surface of the annular
tread perpendicular to the axial direction.
"Equatorial plane (EP)" means the plane perpendicular to the tire's axis of rotation and passing through
the center of its tread.
"Footprint" means the contact patch or area of contact of the tire tread with a flat surface at zero speed
and under normal load and pressure.
"Groove" means an elongated void area in a tread
that may extend circumferentially or laterally about
the tread in a straight, curved, or zigzag manner.
Circumferentially and laterally extending grooves
sometimes have common portions. The "groove
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45
50
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width" is equal to tread surface are occupied by a
groove or groove portion, the width of which is in
question, divided by the length of such groove or
groove portion; thus, the groove width is its average
width over its length. Grooves may be of varying
depths in a tire. The depth of a groove may vary
around the circumference of the tread, or the depth
of one groove may be constant but vary from the
depth of another groove in the tire. If such narrow
or wide grooves are of substantially reduced depth
as compared to wide circumferential grooves which
they interconnect, they are regarded as forming "tie
bars" tending to maintain a rib-like character in the
tread region involved.
"Inboard side" means the side of the tire nearest the
vehicle when the tire is mounted on a wheel and the
wheel is mounted on the vehicle.
"Lateral" means an axial direction.
"Net contact area" means the total area of ground
contacting elements between defined boundary
edges divided by the gross area between the
boundary edges as measured around the entire circumference of the tread.
"Net-to-gross ratio" means the total area of ground
contacting tread elements between the lateral edges around the entire circumference of the tread divided by the gross area of the entire tread between
the lateral edges.
"Non-directional tread" means a tread that has no
preferred direction of forward travel and is not required to be positioned on a vehicle in a specific
wheel position or positions to ensure that the tread
pattern is aligned with the preferred direction of travel. Conversely, a directional tread pattern has a preferred direction of travel requiring specific wheel positioning. "Axial" and "axially" means lines or directions that are parallel to the axis of rotation of the
tire.
"Outboard side" means the side of the tire farthest
away from the vehicle when the tire is mounted on
a wheel and the wheel is mounted on the vehicle.
"Radial" and "radially" means directions radially toward or away from the axis of rotation of the tire.
"Rib" means a circumferentially extending strip of
rubber on the tread which is defined by at least one
circumferential groove and either a second such
groove or a lateral edge, the strip being laterally undivided by full-depth grooves.
"Sipe" means small slots molded into the tread elements of the tire that subdivide the tread surface
and improve traction.
"Tread element" or "traction element" means a rib,
lug or a block element.
Detailed Description of the Invention
[0019] With the reference to FIGURES 1-6, a tire (10)
having a tread (20) according to a preferred embodi-
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EP 1 093 939 B1
ment of the present invention is shown. The tread (20)
when configured annularly has an axis of rotation R, first
and second lateral edges (24, 26).
[0020] The tread (20) has a plurality of ground engaging traction elements (40, 42, 44) separated by circumferential grooves (53, 54, 55, 56) and lateral grooves
(57, 58). Each traction element (42) extends radially outwardly from a tread base (22) to a radially outer surface.
The lateral grooves (57, 58) may intersect the circumferential grooves and join to form a continuous lateral
groove path across the entire tread width. Preferably,
the lateral grooves (57, 58) may begin in the center of
the tread at ends which are laterally or circumferentially
spaced and never connecting, except that they may
meet at a common circumferential groove (53, 55). The
traction elements (42) as shown are chevron-shaped
traction elements. The tread (20), as illustrated in FIGURES 1-6, has an overall or total net-to-gross ratio of
about 60% measured from tread lateral edge (24) to
tread lateral edge (26). It is believed that the tire (10)
can be successfully produced with treads (20) having
low total or overall net-to-gross ratios between 40% and
70%, preferably 45% to 65%.
[0021] The tread (20) is divided laterally into three
tread zones, (12, 14, 16). The middle zone (14) is positioned between the axially outer portion of the enlarged
lug end (45) of the lug (44) on each tread half. The first
shoulder zone (12) is located between the first lateral
edge (24) and the enlarged lug end (45) of a lug (44) of
the first row (2). The second shoulder tread zone (16) is
located between the second lateral edge (26) and the
enlarged lug end (45) of the lug (44) of the second row
(6). The first or second shoulder tread zones (12, 16)
are intended to be mounted on either the outer or outboard side of the vehicle (not shown) or on the inboard
side. The first and second shoulder tread zones (12, 16)
preferably have a net contact area less than the net contact area of the middle zone (14). Each tread zone is
defined as the area between specified boundary edges.
The middle zone (14) has boundary edges defined by
two planes (A, B), one plane (A) passes through the axially outer portion of each enlarged axially inner end (45)
of the shoulder lug (44) located closer to the tread lateral
edge (24), plane B being similarly situated but closer to
tread lateral edge (26).
[0022] The first shoulder zone (12) lies between the
lateral edge (24) and the plane (A).
[0023] The second shoulder zone (16) lies between
the lateral edge (26) and the plane (B). The axial width
of the shoulder zones (12, 16) are less than 30% of the
overall tread width (TW), while the middle zone has an
axial width of at least 40% or greater of the overall tread
width (TW).
[0024] As shown, the circumferentially adjacent and
alternating oriented chevrons (42) of the middle row (4)
has the truncated apex (43) located axially inward of
most of the open portions (50) of the oppositely oriented
and circumferentially adjacent chevrons (42). The com-
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45
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bination of the truncated apex (43) and the portions of
the two circumferentially adjacent chevrons (42) envelope at least one half of the enlarged axially inner ends
(45) of the second laterally extending shoulder lugs (44).
[0025] The combination of the middle row (4) of chevron-shaped traction elements (42) and the shoulder
rows (2, 6) of laterally extending first laterally extending
shoulder lug (40) and the second laterally extending
shoulder lug (44) form three circumferentially aligned
traction elements (40, 42, 44) having a first laterally extending shoulder lug (40), a middle chevron-shaped
traction element (42) and a second laterally extending
shoulder lug (44), respectively extending from a first
tread shoulder or edge (24) to the opposite second tread
shoulder or edge (26), the circumferentially adjacent
lugs (40, 44) and chevron (42) are arranged from the
first tread shoulder or edge (24) to the second tread
shoulder or edge (26) with the second lug (44) being in
closer proximity to the first shoulder or first lateral edge
(24) and the first lug (40) being adjacent to the second
lateral edge (26).
[0026] As illustrated, the second shoulder lugs (44)
have an axially outer end (47) offset axially inwardly of
the axially outer end (49) of the lugs (40).
[0027] Interestingly, as shown in FIGURE 5, the lugs
(40, 44) and the chevron-shaped traction elements (42)
are circumferentially aligned such that a centerline (CL)
bisecting each element (40, 42, 44) are circumferentially
aligned. That is an axial straight line (70) extending from
the first lateral edge (24) to the second lateral edge and
through each of the centerlines (CL) of the lugs (40, 42,
44) can be drawn in each repeating pattern of the three
traction elements (40, 42, 44).
[0028] Another beneficial feature of the tread (20) is
that the sides (80) of the elements (40, 42, 44) extending
radially from the tread base (22) to a radially outer edge
of the element is inclined at a large angle θ in locations
where the sides (80) face oppositely to or is part of an
axially inner end (41) of the lug (40) or the sides (80)
face oppositely to or is part of an axially inner end (45)
of the lug (44). Thus, the sides (80) of truncated apex
(43) and the sides (80) adjacent the open end (50) of
the chevron-shaped traction elements (42) are inclined
at the angle θ, θ being at least 20° inclined relative to
the radial direction, preferably about 30°. Also, as illustrated, the corners (90) where the sides (80) are generously sloped and intersect, preferably are chamfered.
[0029] The combination of chamfered corners (90)
and sloping sides (80) buttress the elements (40, 42,
44) increasing the stiffness of the tread (20), particularly
in the middle tread zone (14) as shown. This feature enables the tread (20) to increase the net area in the center
region of the tread as the tread wears. This increasing
net area retards treadwear in the center region of the
tread.
[0030] In the shoulder regions, the sharper angled
sides enhance traction in soft, wet, or snowy conditions.
[0031] In the shoulder lugs (40), a blind groove (62)
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laterally bisects the axially outer portion of the lug (40)
adjacent each lateral edge (24, 26). In the shoulder lug
(44), a shallow depth semi-blind groove (64) bisects the
axially outer portion of the lug (44) adjacent the lateral
edges (24, 26). Also, the enlarged axially inner end (45)
of lug (44) has a semi-blind groove (60) bisecting laterally the end (45). Each of these features provide additional edges to enhance traction but also increases the
flexibility of the lugs (40, 44) in the circumferential direction which enhances ride performance and traction.
[0032] Although not illustrated, it is understood that
the tread pattern may employ a pitched pattern to improve noise dampering, if so desired.
[0033] The sloping narrow inner end (41) creates a
very open tread void area in the central portion of the
tread (20) which facilitates the tread from becoming
packed with mud in this portion of the tread, as well as
the other areas having the generously sloped sides (80).
[0034] The tread (20), as illustrated, has excellent ride
characteristics due in part to the amount of tread in road
contact, particularly in the center of the tread.
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middle row (4) of the chevron-shaped traction elements (42) and the first and second shoulder rows
(2, 6) of the laterally extending shoulder lugs (40,
44) form three circumferentially aligned traction elements (40, 42, 44) having the first lateral extending
shoulder lug (40), the middle chevron-shaped traction element (42) and the second laterally extending
shoulder lug (44), respectively, extending from a
first tread shoulder (24) to an opposite second tread
shoulder (26); and wherein the circumferentially adjacent lugs (40, 44) are arranged from the first tread
shoulder (24) to the second tread shoulder (26) with
the second laterally extending shoulder lug (44), the
middle chevron-shaped traction element (42) and
the first laterally extending lug (40), respectively, in
a repeating alternating pattern.
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4.
The tread of claim 1, wherein axially outer ends (47,
49) of the shoulder lugs (40,44) are axially offset,
the outer ends (47) of the second laterally extending
shoulder lugs (44) being axially inward of the axially
outer end (49) of the first laterally extending shoulder lugs (40).
5.
The tread of claim 1 wherein the tread (20) has a
tread width (Tw), the tread width having a middle
portion (14) defined by planes (A) and planes (B)
passing through axially outer portions of the enlarged lug heads (45) of the second laterally extending shoulder lugs (44), and a first shoulder portion
(12) extending from the first tread shoulder (24) to
the plane (A) and a second shoulder portion (16)
extending from the second shoulder (26) to the
plane (B), and wherein the middle portion (14) is at
least 40% of the tread width (Tw) while the shoulder
portions (12, 16) are each less than 30% of the tread
width (Tw).
6.
The tread of claim 5, wherein the net-to-gross ratio
of the middle portion (14) is greater than 50% and
the net-to-gross ratio of the shoulder portions
(12,16) is less than 40%.
7.
The tread of claim 1, wherein the first laterally extending shoulder lug (40), the second laterally extending shoulder lug (44) and the chevron-shaped
traction element (42) are circumferentially aligned
such that a line (70) bisecting each aligned lug (40,
44) and chevron-shaped traction element (42) is laterally extending.
8.
The tread of claim 1, wherein the center of the first
laterally extending shoulder lug (40) and the center
of the second laterally extending shoulder lug (44)
are circumferentially aligned with the center of the
truncated apex (43) of the chevron-shaped traction
element (42).
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Claims
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1.
2.
3.
A tread (20) for a pneumatic tire (10), wherein the
tread has a plurality of traction elements (40, 42,
44) arranged in three circumferentially repeating
rows (2, 4, 6); a middle row (4), a first shoulder row
(2) and a second shoulder row (6); wherein the middle row (4) has chevron-shaped elements (42) having a truncated apex (43), each adjacent chevronshaped traction element (42) alternating in orientation circumferentially around the tread; wherein
each shoulder row (2, 6) has a pair of laterally extending shoulder lugs (40, 44); a first laterally extending shoulder lug (40) having a narrow axially
inner end directed circumferentially aligned with the
truncated apex (43) of the chevron-shaped traction
element (42) and extending toward and adjacent to
an open end (50) of the chevron-shaped traction element (42), and a second laterally extending shoulder lug (44) having an enlarged axially inner end
(45) circumferentially aligned with and extending toward and adjacent to the truncated apex (43) of the
chevron-shaped traction element(42), characterized in that the first laterally extending shoulder lug
(40) has the narrow axially inner end (41) sloping
radially inwardly to a location about halfway or at
least halfway into the open end (50) of the chevronshaped traction element (42).
The tread of claim 1, wherein the second laterally
extending shoulder lug (44) has a laterally extending semi-blind groove (60) bisecting the enlarged
axially inner end (45).
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The tread of claim 1, wherein the combination of the
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EP 1 093 939 B1
The tread of claim 1, wherein the sides (80) of the
traction elements (40, 42, 44) extending radially
from the tread base (22) to a radially outer edge of
the traction elements (40, 42, 44) are inclined at a
large angle in locations where the sides (80) face
oppositely to or are part of an axially inner end (41,
45) of the lugs (40, 44).
10. The tread of claim 9, wherein the sides (80) of the
truncated apex (43) and the sides (80) adjacent the
open end (50) of the chevron-shaped traction elements (42) are inclined at the angle θ, θ being at
least 20° inclined to the radial direction, preferably
about 30°.
migen Antriebselements (42) ausgerichtet ist und
sich hin zu und benachbart zu diesem erstreckt, dadurch gekennzeichnet, dass das schmale Ende
(41) des ersten sich seitwärts erstreckenden Schulterstollens (40) radial nach innen zu einer Stelle etwa zur Hälfte oder zumindest zur Hälfte in das offene Ende (50) des chevronförmigen Antriebselements (42) abfällt.
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2.
Die Lauffläche gemäß Anspruch 1, wobei der zweite sich seitlich erstreckende Schulterstollen (44) eine sich seitlich erstreckende halb abgeschlossene
Rille (60) aufweist, die das vergrößerte axial innere
Ende (45) halbiert.
3.
Die Lauffläche gemäß Anspruch 1, wobei die Kombination der mittleren Reihe (4) der chevronförmigen Antriebselemente (42) und der ersten und
zweiten Schulterreihen (2, 6) der sich seitlich erstreckenden Schulterstollen (40, 44) drei in Umfangsrichtung ausgerichtete Antriebselemente (40,
42, 44) bildet, wobei der erste sich seitlich erstrekkende Schulterstollen (40), das mittlere chevronförmige Antriebselement (42) beziehungsweise der
zweite sich seitlich erstreckende Schulterstollen
(44) sich von einer ersten Laufflächenschulter (24)
zu einer gegenüberliegenden zweiten Laufflächenschulter (26) erstrecken; und wobei die in Umfangsrichtung benachbarten Stollen (40, 44) von der ersten Laufflächenschulter (24) zu der zweiten Laufflächenschulter (26) mit dem zweiten sich seitlich
erstreckenden Schulterstollen (44), dem mittleren
chevronförmigen Antriebselement (42) beziehungsweise dem ersten sich seitlich erstreckenden
Stollen (40) in einem sich wiederholenden abwechselnden Muster angeordnet sind.
4.
Die Lauffläche gemäß Anspruch 1, wobei axial äußere Enden (47, 49) der Schulterstollen (40, 44) axial seitlich versetzt sind, wobei die äußeren Enden
(47) der zweiten sich seitlich erstreckenden Schulterstollen (44) sich axial nach innen in Bezug zu
dem axial äußeren Ende (49) der ersten sich seitlich
erstreckenden Schulterstollen (40) befinden.
5.
Die Lauffläche gemäß Anspruch 1, wobei die Lauffläche (20) eine Laufflächenbreite (Tw) aufweist,
wobei die Laufflächenbreite einen Mittelteil (14) hat,
der durch Ebenen (A) und Ebenen (B) definiert ist,
die durch axial äußere Teile der vergrößerten Stollenköpfe (45) der zweiten sich seitlich erstreckenden Schulterstollen (44) verlaufen, und einen ersten Schulterteil (12), der sich von der ersten Laufflächenschulter (24) zu der Ebene (A) erstreckt, und
einen zweiten Schulterteil (16), der sich von der
zweiten Schulter (26) zu der Ebene (B) erstreckt,
und wobei der Mittelteil (14) zumindest 40% der
Laufflächenbreite (Tw) beträgt, während die Schul-
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11. The tread of claim 9 or 10, wherein the corners
where the sides (80) are generously sloped and intersect are chamfered.
12. The tread of claim 1, wherein in the first laterally extending shoulder lugs (40), a blind groove (62) laterally bisects the axially outer portion of the first laterally extending shoulder lug (40) adjacent each
tread lateral edge (24, 26).
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13. The tread of claim 1, wherein in the second laterally
extending shoulder lug (44), a shallow depth semiblind groove (64) bisects the axially outer portion of
the second laterally extending shoulder lug (44) adjacent the tread lateral edges (24, 26).
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Patentansprüche
1.
Eine Lauffläche (20) für einen Pneumatikreifen (10),
wobei die Lauffläche eine Vielzahl von Antriebselementen (40, 42, 44) aufweist, die in drei sich in Umfangsrichtung wiederholenden Reihen (2, 4, 6) angeordnet sind; einer mittleren Reihe (4), einer ersten Schulterreihe (2) und einer zweiten Schulterreihe (6); wobei die mittlere Reihe (4) chevronförmige Elemente (42) mit einem abgestumpften
Scheitel (43) aufweist, wobei jedes benachbarte
chevronförmige Antriebselement (42) in Umfangsrichtung um die Lauffläche (20) von Orientierung
wechselt; wobei jede Schulterreihe (2, 6) ein Paar
sich seitwärts erstreckender Schulterstollen (40,
44) aufweist; einen ersten sich seitwärts erstrekkenden Schulterstollen (40) mit einem schmalen
axial inneren Ende (41), das in Umfangsrichtung mit
dem abgestumpften Scheitel (43) des chevronförmigen Antriebselements (42) ausgerichtet ist und
sich hin zu und benachbart zu einem offenen Ende
(50) des chevronförmigen Antriebselements (42)
erstreckt, und einen zweiten sich seitlich erstrekkenden Schulterstollen (44) mit einem vergrößerten
axial inneren Ende (45), das in Umfangsrichtung zu
dem abgestumpften Scheitel (43) des chevronför-
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40
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streckenden Schulterstollens (44) benachbart zu
den Laufflächenseitenkanten (24, 26) halbiert.
terteile (12, 16) jeder weniger als 30% der Laufflächenbreite (Tw) betragen.
6.
7.
8.
Die Lauffläche gemäß Anspruch 5, wobei das Netto-Brutto-Verhältnis des Mittelteils (14) größer als
50% und das Netto-Brutto-Verhältnis der Schulterteile (12, 16) kleiner als 40% ist.
Die Lauffläche gemäß Anspruch 1, wobei der erste
sich seitlich erstreckende Schulterstollen (40), der
zweite sich seitlich erstreckende Schulterstollen
(44) und das chevronförmige Antriebselement (42)
in Umfangsrichtung ausgerichtet sind, sodass eine
Linie (70), die jeden ausgerichteten Stollen (40, 44)
und jedes chevronförmige Antriebselement (42)
halbiert, sich seitlich erstreckt.
Die Lauffläche gemäß Anspruch 1, wobei das Zentrum des ersten sich seitlich erstreckenden Schulterstollens (40) und das Zentrum des zweiten sich
seitlich erstreckenden Schulterstollens (44) in Umfangsrichtung zu dem Zentrum des abgestumpften
Scheitels (43) des chevronförmigen Antriebselements (42) ausgerichtet sind.
5
Revendications
1.
Bande de roulement (20) pour un bandage pneumatique (10), dans laquelle la bande de roulement
possède plusieurs éléments de traction (40, 42, 44)
arrangés pour former trois rangs qui se répètent en
direction circonférentielle (2, 4, 6), un rang médian
(4), un premier rang d'épaulement (2) et un deuxième rang d'épaulement (6) ; dans laquelle le rang
médian (4) possède des éléments en forme de chevron (42) comportant un sommet tronqué (43), chaque élément de traction adjacent (42) en forme de
chevron alternant en direction circonférentielle
autour de la bande de roulement ; dans laquelle
chaque rang d'épaulement (2, 6) possède une paire
de barrettes d'épaulements (40, 44) s'étendant en
direction latérale, une première barrette d'épaulement (40) s'étendant en direction latérale possédant une extrémité interne étroite en direction axiale
orientée en direction circonférentielle, en alignement avec le sommet tronqué (43) de l'élément de
traction (42) en forme de chevron et s'étendant en
direction de l'extrémité ouverte (50) de l'élément de
traction (42) en forme de chevron, et en position adjacente audit élément, et une deuxième barrette
d'épaulement (44) s'étendant en direction latérale
possédant une extrémité interne (45) élargie en direction axiale disposée en alignement circonférentiel avec le sommet tronqué (43) de l'élément de
traction (42) en forme de chevron et s'étendant en
direction dudit sommet et en position adjacente
audit sommet, caractérisée en ce que l'extrémité
interne (41) étroite en direction axiale de la première barrette d'épaulement (40) s'étendant en direction latérale présente une inclinaison tournée vers
l'intérieur en direction radiale jusqu'à un endroit situé approximativement à mi-distance ou au moins
à mi-distance dans l'extrémité ouverte (50) de l'élément de traction (42) en forme de chevron.
2.
Bande de roulement selon la revendication 1, dans
laquelle la deuxième barrette d'épaulement (44)
s'étendant en direction latérale possède une rainure semi-borgne (60) s'étendant en direction latérale
qui coupe en deux l'extrémité interne (45) élargie
en direction axiale.
3.
Bande de roulement selon la revendication 1, dans
laquelle la combinaison du rang médian (4) des éléments de traction (42) en forme de chevron et des
premier et deuxième rangs d'épaulements (2, 6)
des barrettes d'épaulements (40, 44) s'étendant en
direction latérale forme trois éléments de traction
(40, 42, 44) disposés en alignement circonférentiel,
10
15
20
25
9.
Die Lauffläche gemäß Anspruch 1, wobei die Seiten
(80) der Antriebselemente (40, 42, 44), die sich radial von der Laufflächenbasis (22) zu einer radial
äußeren Kante der Antriebselemente (40, 42, 44)
erstrecken, an Stellen, wo die Seiten (80) einem
axial inneren Ende (41, 45) der Stollen (40, 44) gegenüberstehen oder einen Teil davon bilden, in einem großen Winkel θ geneigt sind.
10. Die Lauffläche gemäß Anspruch 9, wobei die Seiten
(80) des abgestumpften Scheitels (43) und die Seiten (80) benachbart zu dem offenen Ende (50) der
chevronförmigen Antriebselemente (42) in dem
Winkel θ geneigt sind, wobei θ zumindest 20°, vorzugsweise etwa 30°, zur radialen Richtung geneigt
ist.
11. Die Lauffläche gemäß Anspruch 9 oder 10, wobei
die Ecken, wo die Seiten (80) großzügig abfallend
geformt sind und einander schneiden, abgefast
sind.
12. Die Lauffläche gemäß Anspruch 1, wobei in den ersten sich seitlich erstreckenden Schulterstollen (40)
eine abgeschlossene Rille (62) seitlich den axial äußeren Teil des ersten sich seitlich erstreckenden
Schulterstollens (40) benachbart zu jeder Laufflächenseitenkante (24, 26) halbiert.
13. Die Lauffläche gemäß Anspruch 1, wobei in dem
zweiten sich seitlich erstreckenden Schulterstollen
(44) eine untiefe halb abgeschlossene Rille (64)
den axial äußeren Teil des zweiten sich seitlich er-
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40
45
50
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la première barrette d'épaulement (40) s'étendant
en direction latérale, l'élément de traction médian
(42) en forme de chevron et la deuxième barrette
d'épaulement (44) s'étendant en direction latérale,
respectivement, s'étendant depuis un premier
épaulement de bande de roulement (24) jusqu'à un
deuxième épaulement de bande de roulement opposé (26) ; et dans laquelle les barrettes adjacentes
(40, 44) en direction circonférentielle sont arrangées depuis le premier épaulement de bande de
roulement (24) jusqu'au deuxième épaulement de
bande de roulement (26) de telle sorte que la
deuxième barrette d'épaulement (44) s'étendant en
direction latérale, l'élément de traction médian (42)
en forme de chevron et la première barrette (40)
s'étendant en direction latérale, respectivement,
sont disposées dans une structure alternante qui se
répète.
4.
Bande de roulement selon la revendication 1, dans
laquelle les extrémités externes (47, 49) en direction axiale des barrettes d'épaulement (40, 44) sont
décalées en direction axiale, les extrémités externes (47) des deuxièmes barrettes d'épaulements
(44) s'étendant en direction latérale étant disposées
à l'intérieur, en direction axiale, des extrémités externes (49) en direction axiale des premières barrettes d'épaulements (40) s'étendant en direction
latérale.
Bande de roulement selon la revendication 1, dans
laquelle la bande de roulement (20) possède une
largeur de bande de roulement (Tw), la largeur de
bande de roulement possédant une portion médiane (14) définie par des plans (A) et des plans (B)
passant par des portions externes en direction axiale des têtes de barrettes élargies (45) des deuxièmes barrettes d'épaulement (44) s'étendant en direction latérale, une première portion d'épaulement
(12) s'étendant depuis le premier épaulement de
bande de roulement (24) jusqu'au plan (A) et une
deuxième portion d'épaulement (16) s'étendant depuis le deuxième épaulement (26) jusqu'au plan
(B) ; et dans laquelle la portion médiane (14) représente au moins 40 % de la largeur de bande de roulement (Tw), tandis que les portions d'épaulements
(12, 16) représentent respectivement moins de 30
% de la largeur de bande de roulement (Tw).
6.
Bande de roulement selon la revendication 5, dans
laquelle le rapport net-brut de la portion médiane
(14) est supérieur à 50 % et le rapport net-brut des
portions d'épaulements (12, 16) est inférieur à 40
%.
7.
Bande de roulement selon la revendication 1, dans
laquelle la première barrette d'épaulement (40)
s'étendant en direction latérale, la deuxième barret-
8.
Bande de roulement selon la revendication 1, dans
laquelle le centre de la première barrette d'épaulement (40) s'étendant en direction latérale et le centre de la deuxième barrette d'épaulement (44)
s'étendant en direction latérale sont disposés en alignement circonférentiel avec le centre du sommet
tronqué (43) de l'élément de traction (42) en forme
de chevron.
9.
Bande de roulement selon la revendication 1, dans
laquelle les côtés (80) des éléments de traction (40,
42, 44) s'étendant en direction radiale à partir de la
de base (22) de bande de roulement jusqu'à un bord
externe, en direction radiale, des éléments de traction (40, 42, 44) sont inclinés en formant un grand
angle θ aux endroits où les côtés (80) font face à
l'extrémité interne (41, 45), en direction axiale, des
barrettes (40, 44) ou font partie de ladite extrémité.
10
15
25
30
5.
te d'épaulement (44) s'étendant en direction latérale et l'élément de traction (42) en forme de chevron
sont disposés en alignement circonférentiel de telle
sorte qu'une ligne (70) qui coupe en deux chaque
barrette (40, 44) et chaque élément de traction (42)
en forme de chevron disposé en alignement s'étend
en direction latérale.
5
20
14
10. Bande de roulement selon la revendication 9, dans
laquelle les côtés (80) du sommet tronqué (43) et
les côtés (80) adjacents à l'extrémité ouverte (50)
des éléments de traction (42) en forme de chevron
sont inclinés en formant un angle θ, θ représentant
une inclinaison d'au moins 20° en direction radiale,
de préférence d'environ 30°.
35
11. Bande de roulement selon la revendication 9 ou 10,
dans laquelle les coins, à l'endroit où les côtés (80)
présentent une forte pente et se coupent, sont
chanfreinés.
40
45
50
55
8
12. Bande de roulement selon la revendication 1, dans
laquelle, dans les premières barrettes d'épaulements (40) s'étendant en direction latérale, une rainure borgne (62) coupe latéralement en deux parties la portion externe, en direction axiale, de la première barrette d'épaulement (40) s'étendant en direction latérale, en position adjacente à chaque
bord latéral (24, 26) de la bande de roulement.
13. Bande de roulement selon la revendication 1, dans
laquelle, dans la deuxième barrette d'épaulement
(44) s'étendant en direction latérale, une rainure
semi-borgne peu profonde (64) coupe en deux parties la portion externe, en direction axiale, de la
deuxième barrette d'épaulement (44) s'étendant en
direction latérale, en position adjacente aux bords
latéraux (24, 26) de la bande de roulement.
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