Compagnie Generale Des Etablissements Michelin

Michelin Recherche Et Technique S.a.

Societe Detechnologie Michelin

Vincent Estenne

Alain Domingo

Emmanuel Clement

Michael Cogne

Emmanuel Joulin

Charlotte Caffeau

Laurent Bucher

Cédric Khayat

A radial tire () for a heavy-duty vehicle of construction plant type, and to reduce the risk of tire tread separation when running over sharp stones, while at the same time ensuring that the crown reinforcement exhibits good resistance to cracking. The tire () has a protective reinforcement () having three protective layers (), comprising metal reinforcers that respectively have a diameter (D1, D2, D3) and are distributed at an axial spacing (P1, P2, P3). According to the invention, with Alpha1, Alpha2 and Alpha3 being the angles of the reinforcers of the respective layers () with the circumferential direction, the following relationships are satisfied:15°≤|Alpha1|≤40°15°≤|Alpha2|≤40°Alpha1*Alpha2≤035°≤|Alpha3|≤75°As regards the differences between the angles of the reinforcers of the protective layers, the following relationship in terms of absolute values applies:|(Alpha1−Alpha3)|≥10°|(Alpha2−Alpha3)|≥10°.

Tire for a heavy-duty vehicle of construction plant type, provided with a protective reinforcement having three differentiated layers

Improving the endurance of the beads () of a radial tire for a civil-engineering heavy vehicle by proposing a solution which blocks the propagation of the cracks initiated in the coating elastomer of the bead reinforcing layer (), by inserting a cushion rubber () interposed between the coating elastomer of the carcass layer turn-up () and the coating elastomer of the bead reinforcing layer (). The elastic modulus in extension of the cushion rubber () measured at 100% deformation must be less than the elastic modulus of the coating compound of the carcass layer. Still according to a disclosed embodiment, the thickness of the cushion rubber () is at least equal to the thickness of the bead reinforcing layer ().

Bead for a tire for a civil-engineering heavy vehicle

A hooping reinforcement of a tire for a heavy duty civil engineering type vehicle is disclosed. The crown reinforcement () of the tire (), radially on the inside of a tread (), comprises a protective reinforcement (), a working reinforcement () and a hooping reinforcement (). Said hooping reinforcement () has an axial width at most equal to the smallest axial width (L, L) of the two working layers (), and comprises at least two hooping layers () that are formed from strips each made up of elastic metal reinforcers. Each hooping layer () is made up of an axial juxtaposition of contiguous turns of the strip (), which are circumferentially wound around the working layer (). Each strip () is at least 35 mm and at most 250 mm thick, and its distributed breaking tension is at least equal to 100 daN/mm.

Hooping reinforcement for a tire of a heavy duty civil engineering vehicle

Heavy vehicle tire with two beads () contacting rim () an outer face (), radial carcass reinforcement () having carcass layer () wound within each bead () around bead wire () having center (O) to form turnup (), additional circumferential reinforcement (), in each bead (), having additional layer (), additional reinforcement () extending radially from radially inner end (E) to radially outer end (E) and axially on outerside of axially outermost turnup (). The orthogonal projection (P) of radially inner end (E) of additional circumferential reinforcement () onto axially outer face () of bead () is radially on outside of center (O) of bead wire (), the orthogonal projection (P) of radially outer end (E) of additional circumferential reinforcement () onto axially outer face () of the bead () contacting point (P') of rim () that is axially on inside of point (C) of last contact of rim () when tire () is mounted and inflated, and radial distance (d) between end (E) and end (E) of additional circumferential reinforcement () is at most 20 mm.

Heavy vehicle tire bead

The tire comprises a tread, a crown reinforcement and at least one crown layer. The crown layer has an axial width (L) that is at least two-thirds of a maximum axial width (L) of the tire and has a concave portion with axial limits (M, M') on either side of an equatorial plane (XZ). The tire further includes a carcass reinforcement which has at least one carcass layer with a concave portion that has axial limits (M, M&#x2032;) on either side of the equatorial plane (XZ). The radial distance (d) between the respective concave portions is at a maximum in the equatorial plane (XZ) and decreases continuously from the equatorial plane (XZ) as far as the axial limits (M, M&#x2032;) of the said concave portions axially closest to the equatorial plane (XZ), where it reaches a minimum value (d).

Aeroplane tire with crown and carcass both having a concave portion

An improvement in an airplane tire to obtain a more even distribution of temperature within the crown of the tire. An airplane tire comprises a crown reinforced by a working reinforcement (), comprising at least one layer of working reinforcement () made up of axially juxtaposed substantially circumferential strips () made up of mutually parallel textile reinforcing elements () coated with a polymer coating material (). Each strip is in contact, over at least its radially inner axial face, with a heat transfer element () comprising at least one heat-conducting material with thermal conductivity at least equal to 50 times the thermal conductivity of the polymer coating material. The product of the thickness of a heat transfer element by the tension modulus of a heat transfer element is at most equal to 0.3 times the product of the thickness of the strip by the tension modulus of the strip.

Crown reinforcement for aircraft tire

Tire () comprising a radial carcass reinforcement () anchored in beads, the tire () comprising two sidewalls (), each sidewall () extending between a bead () and a crown (), the two sidewalls comprising a first additional reinforcement () positioned either between the carcass reinforcement and the internal cavity of the tire or axially on the outside of the carcass reinforcement and at least one of the sidewalls comprising a second additional reinforcement (), this tire being characterized in that the first additional reinforcement comprises a plurality of reinforcing elements of textile nature oriented at an angle at least equal to 80&#xb0; and at most equal to 90&#xb0; to the circumferential direction, and in that the second additional reinforcement () comprises, in the circumferential direction and in an alternating manner, a plurality of first parts () and of second parts (), these second parts (), having a mean width at least equal to 20 mm, these first and second parts having ultimate tensile strengths, that is to say forces at break per unit width of reinforcement, which are such that the ultimate tensile strength of the second parts () is lower than the ultimate tensile strength of the first parts, and in that the first and second additional reinforcements are positioned one on each side of the carcass reinforcement.

Growing community of inventors

Clermont-Ferrand, France

Vincent Estenne