Abstract:
In a pneumatic tire comprising a tread portion divided into a central region and both side regions, at least one rib-shaped main land part is formed in the central region and a plurality of main slant grooves are arranged so as to extend obliquely from the central region toward each tread end of the tread portion with respect to the equatorial plane to form first slant land parts among these main slant grooves, in which the first slant land part has a plane form of approximately a triangle, and a first auxiliary land part is arranged between the rib-shaped main land part and the main slant groove.
Abstract:
A very high performance tire (1, 101) for vehicles comprises a tread (14) provided with a plurality of transversal grooves (15) circumferentially distributed along the tread (14) in groups alternately extending from opposite shoulder zones (F, G) of the tread (14). The transversal grooves (15) define in an equatorial zone (E) of the tread (14) a substantially isotropic matrix of substantially continuous portions (18) of the tread (14) terminating at an equatorial portion (17) of a same transversal groove (15) of the axially opposite group of grooves.
Abstract:
A tread 2 for a pneumatic tire 1 has a central portion defining two circumferentially extending center ribs 22, 23 having an axial width RW, and RN2 ranging from 5% to 25% of the tread width TW. The centermost circumferentially extending groove 8 has on both sides a tapered groove wall edges which form with a plane parallel to the equational plane acute angles &agr;1 and &agr;2 ranging between 1 and 10°. The tread height near both edges of the centermost groove extend radially above the average tread height a maximum extra tread height of between 0.3 mm and 1.7 mm. The extra tread height diminishes progressively from the groove edges P0 P1 toward the respective shoulder 3,4 a distance not exceeding 10% of the treadwidth.
Abstract:
A tire tread having design cycles or pitches in which the circumferential lengths of repeated pitches are randomly modulated in certain selected sequences to reduce the amount of noise generated by the tire tread when the tire rolls on a road surface. The pitch sequences include three different circumferential pitch lengths including a group having a largest number of medium length (M) pitches, a smallest number of shortest length pitches (S) and a medium number of longest length (L) pitches. In one embodiment, the ratio of the three different pitches are 0.8 for the smallest length pitch (S), 1 for the medium length pitch (M) and 1.2 for the longest length pitch (L). 100 pitch sequences are proposed with the sequence L M S M S L M L M L M L M L M M L M L M L M L M L M being the preferred sequence which provides the most noise reduction. Ninety nine other pitches are also within a range to provide an acceptable level of noise reduction in a tire tread.
Abstract translation:具有设计周期或间距的轮胎胎面,其中重复间距的圆周长度以某些选定的顺序随机调制,以减少当轮胎在路面上滚动时由轮胎胎面产生的噪声的量。 间距序列包括三个不同的圆周间距长度,包括具有最大数量的中等长度(M)间距,最小数量的最短长度间距(S)和最大长度(L)间距的中等数量的组。 在一个实施例中,对于最小长度间距(S),三个不同间距的比率为0.8,对于中等长度间距(M)为1,对于最长长度间距(L)为1.2。 提出了100个节点序列,具有序列L M S M S L M L M L M L M L M M L M L M L M L M L M是提供最大降噪的优选序列。 九十九个其他间距也在一个范围内,以提供轮胎胎面中可接受的降噪水平。
Abstract:
A pneumatic tire for motor vehicles has a running surface profile designed in the direction of rotation, with two shoulder regions (S1, S2) each being a constituent of a row of shoulder blocks, and with a middle region (C) separated from them by circumferential grooves (2) running in the circumferential direction; this middle region encompasses the width of the circumferential grooves (2) and covers a minimum width of 60% of the width of the running surface (B), is free from circumferential grooves running in the circumferential direction and is equipped with a number of V-shaped running rills (1), which open into the circumferential grooves (2) and whose V-peaks rest at least essentially on the equator line (M—M). In the two partial regions of the middle region (C) running to the side of the equator line (M—M) there are a number of slanting grooves (4) which are oriented in the same direction to the course of the V-shaped rills (1), crossing at least three V-shaped rills (1) following each other in the circumferential direction and being at least essentially of a straight design, wherein these slanting grooves (4) run at an incline at a much smaller angle (&bgr;, &bgr;′) to the equator line (M—M) than the V-shaped rills (1) and which are the widest of all grooves or rills of the profile, wherein the slanting grooves (4) of the one partial region of the middle region (C) are offset in the circumferential direction with respect to those of the other partial region.
Abstract:
A pneumatic tire comprising a tread portion provided with oblique grooves to define narrow and circumferentially long blocks therebetween, the oblique grooves inclined at angles &thgr; of not more than 60 degrees with respect to the circumferential direction of the tire, each of the long and narrow blocks provided with at least tow sipes each extending across the block from one of the adjacent oblique grooves to the other, while inclining reversely to the oblique grooves, to subdivide the block into at least three block pieces.
Abstract:
A pneumatic tire comprises a pair of bead portions, a pair of sidewall portion, a tread portion, a radial carcass of at least one ply, and a belt, wherein the tread portion is provided with two or more circumferential main grooves formed in a tread rubber at an inner region sandwiched by both shoulder regions and one or more circumferential ribs defined by two adjoining circumferential main grooves, and at least two circumferential fine grooves are formed in the circumferential rib.
Abstract:
A pneumatic tire having an improved tread pattern which is capable of improving the steering stability, tire uniformity and the like without increasing a tread pattern noise is disclosed. The tire comprises rows of circumferentially arranged tread elements such as blocks, the tread elements in each row having plural kinds of different circumferential widths. The circumferential widths of the axial grooves and the circumferential lengths of the tread elements in each row satisfy 1.2≦GR/BR≦1.5 where BR is the length maximum ratio defined by the ratio (Bll/Bss) of the maximum circumferential length (Bll) to the minimum circumferential length (Bss), and GR is the width maximum ratio defined by the ratio (Gll/Gss) of the maximum circumferential width (Gll) to the minimum circumferential width (Gss).
Abstract:
A tread for motor-vehicle tires has a raised pattern formed of a plurality of shaped blocks 7 distributed in circumferential rows 3, 4, 5, 6 disposed in parallel and in side by side relation. The number of the shaped blocks 7 arranged in each row gradually increases while moving from the equatorial plane X—X to the axial outer side edges 1a of the tread 1. Thus a gradual increase in the longitudinal stiffness of the shaped blocks 7 is achieved on passing from the side edges 1a of the tread 1 to the equatorial plane X—X, which brings about a reduction in the mobility of said blocks on the road contact patch and lower rolling noise.
Abstract:
A pneumatic tire comprises a tread portion provided with at least one longitudinal groove extending in the tire circumferential direction and blocks adjacent to one side of the at least one longitudinal groove, each of the blocks being provided with a cut-slope on a corner between the block's top surface and a lateral face facing the longitudinal groove, the cut-slope inclining towards the bottom of the longitudinal groove, and the axial width of the cut-slope gradually decreasing from a middle point of the cut-slope towards each side thereof in the circumferential direction, whereby the vehicle overturn marginal during high speed running is improved.