Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/08—Building tyres
  • B29D30/20—Building tyres by the flat-tyre method, i.e. building on cylindrical drums
  • B29D30/24—Drums
  • B29D30/244—Drums for manufacturing substantially cylindrical tyre components with cores or beads, e.g. carcasses
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/08—Building tyres
  • B29D30/20—Building tyres by the flat-tyre method, i.e. building on cylindrical drums
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/08—Building tyres
  • B29D30/20—Building tyres by the flat-tyre method, i.e. building on cylindrical drums
  • B29D30/30—Applying the layers; Guiding or stretching the layers during application
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/48—Bead-rings or bead-cores; Treatment thereof prior to building the tyre
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/26—Folded plies

Definitions

• the invention relates to the manufacture of a tire whose beads are devoid of bead wires as a means of taking up the tension forces of the carcass reinforcement and of means for clamping said beads on the rim seats on which the said beads are mounted.
• each bead, devoid of rod comprises on the one hand an annular element whose tensile strength in the circumferential direction is significantly lower than that which would be necessary for a rod in a known envelope of the same dimension, the axis of this annular element being the axis of revolution of the envelope, and on the other hand a bead reinforcement reinforcement of at least two reinforcing layers in contact with or near the annular element, the said reinforcing layers each comprising reinforcing elements parallel to each other in each layer, crossed by a layer to the adjacent layer, forming with the circumferential direction an angle ⁇ such that 0 ⁇ ⁇ 10 ° , all of these layers having a tensile strength at least equal to that which would be necessary for a rod in a known envelope of the same dimension
• the mechanical resistance of the bead reinforcement armature is therefore the essential contribution to the mechanical resistance of the bead reinforcing assembly constituted by the annular element and said armature, this assembly thus making it possible to replace the rod of a conventional envelope.
• the carcass reinforcement wraps around the annular element, and the reinforcing layers have their radially upper ends arranged in the bead at different heights.
• the complex formed by the two layers of the bead reinforcement reinforcement and optionally by the annular element, intended to facilitate the manufacture of such a complex and consequently of the tire, can be produced either separately during a previous operation in the preparation of the unvulcanized preform of the carcass reinforcement, that is to say during said preparation of the preform on the drum of the same name.
• angles of reinforcement elements in the vulcanized tire of between 0 ° and 10 °, and preferably 5 ° and less, leads to serious difficulties when cutting desired angles of the plies of non-vulcanized reinforcing elements, as well as during the joining of the widths obtained, difficulties which may result in a lack of precision in the arrangement of the reinforcing layers relative to one another, but also by compared to the neighboring products said layers. Said difficulties are also the cause of significant loss of time in the industrial process and a higher manufacturing cost.
• the invention proposes, for the manufacture of a tire with a radial carcass reinforcement going from one bead to another and with folded edges to form reversals of carcass reinforcement, each bead being devoid of rod and reinforced by a complex of axially adjacent layers of reinforcing elements making with the circumferential direction an angle ⁇ such that 0 ° ⁇ ⁇ 10 °, the carcass reinforcement being wound around said complex for forming a carcass reinforcement upturn, a method characterized in that the complex of axially adjacent layers is produced separately from the carcass reinforcement blank, said production comprising the following steps: a) placing at least one ply of reinforcing elements oriented at an angle ⁇ , such as ⁇ > 10 °, on a laying drum of radius R,
• either the first manufacturing step consists in placing a single ply of parallel elements oriented with the angle ⁇ , and the formation of two crossed layers can be done by folding a part of the ply over the other part of said tablecloth,
• the first step consists of laying two sheets independently of one another on two independent laying drums of radii R and R ', to hold account for the thickness of a sheet, and to extend them to radii Ri and R ' 1; the formation of two layers which can be done by superposition on the drum of radius Ri.
• the folding of one or more plies on themselves can be done without or with the addition of a circular ring, that said folding is carried out in the case of radius R [or that it is carried out in the case of radius R 2 .
• said circular ring is then provided with a small extension module for a certain range of relative elongation ⁇ 0 and with a high module for the values of relative elongation outside the upper limit. from said range, the relative elongation ⁇ 0 corresponding to the passage from the radius Ri to the radius R 2 and is equal to R 2 - R 1 / R l .
• the circular ring is inextensible.
• FIGS. 1A to 1H the diagram of the different stages of manufacturing a complex used in a tire
• FIGS. 2A to 2D a variant of the method according to the invention
• Said ply has an axial width L equal to 86 mm and a total radial thickness e, including calendering, equal to 1 mm.
• a second ply (V) formed of the same cables as those of the ply (1), calenders with the same rubber mixture and being axially spaced apart. each other of the same pitch p 'of 1.25 mm.
• Said cables make the circumferential direction the same angle ⁇ in absolute value but in the opposite direction - ⁇ to the direction of the cables of the ribbon cable (1).
• said ply (1') is placed on the drum T 'of radius R' equal to 164 mm.
• Said ply (V) has an axial width L 'of 66 mm.
• said extension modifies the value of the steps between cables which increase from values p and p 'to values pj and p' l5 such that the ratios pj / p and pVp 'are equal to each other and to the ratio Rj / R.
• the thicknesses of the plies respectively e and e 'become such that ej / e and e'i / e' are equal to R / Rj.
• the two plies (1) and (1 ') in the form of cylindrical rings with internal radii R] and R'i are then transferred and joined (FIG. 1E) on the same drum T, the ply (Y) being superposed radially at the ply (1) so as to obtain a cylindrical sleeve formed by two plies (1) and (1 '), the cables of which are parallel to each other in each ply and crossed from one ply to the next, forming an angle ⁇ with the circumferential direction.
• the cylindrical sleeve formed by the two plies (1) and (Y) of internal radius R then undergoes an extension so that the value of radius R 1 is brought to the value R 2 equal to 331 mm (FIG. IF), and such that, by pantographic effect, the angles + ⁇ and - ⁇ decrease to become the angles + ⁇ and - ⁇ equal to 5 °, such as the axial widths L, and L'of the two layers (1) and (1 ' ) decrease strongly to become L 2 and L ' 2 respectively equal to 43 and 33 mm.
• the steps p 2 and p ' 2 are much smaller than the steps p 1 and p' 1 since a value substantially equal to 0.96 mm is obtained for p 2 and p ' 2 instead of 1.92 mm for the two steps p, and p
• the manufacture of the desired complex ends, in the case described, by the folding of the two plies (1) and (T) on themselves, as shown in FIG. 1G, to obtain the C complex in the unvulcanized state. as it appears on the vulcanized tire, said complex being formed from four layers of textile cables crossed from one ply to the next, making an angle with the circumferential direction substantially equal to 5 °.
• the said complex is then removed from the drum T and transferred to the desired location on the drum for making the raw and cylindrical blank of the carcass reinforcement.
• Said carcass reinforcement is turned around said complex C, and after finishing said raw blank, the latter is transformed into a toroidal blank under the effect of the internal pressure of the conformation membrane of the construction drum.
• the complex C then takes a substantially vertical position with modifications of the laying angles according to the parallel radius considered.
• FIG. 2 shows a simplified manufacturing method for obtaining a complex C with two layers, the said two layers being obtained by folding up a sheet on itself.
• the tablecloth (1) with characteristics identical to the tablecloth (1) previously described above is placed (Figure 2A) on the drum of radius R.
• the ply (1) is then extended ( Figure 2B) so that its internal radius becomes R,, the initial width L and the angle ⁇ of its reinforcement cables not varying during the extension operation. Said ply is folded back on itself (FIG.
• the folding operation being carried out on the drum T, so as to obtain two layers of axial widths L 10 and L ⁇ , the width L 10 of the radially inner layer being greater than the width L / 2 and the width L n of the radially upper layer being less than L / 2.
• the two layers being superimposed, the radius Ri of the laying drum T is increased to the value R 2 (FIG. 2D), an operation making it possible to obtain the final angle ⁇ of the crossed cables of the two layers forming the complex C to l the unvulcanized state, the radius R 2 being, in this case also, slightly greater than the radius of the end of said complex in the vulcanized tire, the end radially closest to the axis of rotation of said tire.
• the manufacturing mode is a mode derived from that shown in FIG. 2 and intended to obtain either a complex with two unfolded layers, or a complex with four layers from two tablecloths folded back on themselves.
• the preliminary steps (not shown) of said mode are the same as steps 2A to 2C of the mode shown in FIG. 2.
• the cylindrical sleeve formed of two layers, obtained by folding over a drum T of radius R] of a sheet ( 1) of reinforcing elements oriented at the angle ⁇ , at the pitch p, and whose widths L 10 and L ⁇ have values on either side of the value L./2, is amputated from its reversal by section of the edge of said reversal (FIG.
• FIG. 3A so as to form a cylindrical sleeve of two layers with free ends (FIG. 3B), a sleeve which is in the same configuration as the sleeve of FIG. 1E of the first example described, with the advantage to have been obtained by the use of a single
• RECTIFIED SHEET (RULE 91) drum and not two drums.
• the reversal is cut by known means, whether conventional such as shears and / or straight or circular knives, or whether they are more advanced such as water jets or the laser beam.
• Said sleeve is then treated in the same manner as above, that is to say extended (FIG. 3C) to a radius R 2 to reach the desired angle, pitch, and widths. It can remain as it is and form in the vulcanized state in the tire a complex C with two unfolded layers, or else undergo the operations as shown in FIGS. 1G at 1 H and lead in the vulcanized state to a complex C of four folded layers.
• FIG. 4 shows an example of folding two plies (1) and (1 ') forming a cylindrical sleeve of radius R 2 , the two plies being composed of textile cables oriented with the angle ⁇ , parallel between in a ply with a single step p 2 and respective widths L 2 and L ' 2 ( Figure 4A).
• the finishing of the sleeve to obtain a four-layer complex is carried out by:

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Tyre Moulding (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

Family

ID=9531704

Family Applications (1)

Country Status (13)

Families Citing this family (4)

Citations (4)

Family Cites Families (3)

• 1998
  • 1998-10-16 FR FR9813052A patent/FR2784614A1/fr active Pending
• 1999
  • 1999-10-11 BR BRPI9914564-2A patent/BR9914564B1/pt not_active IP Right Cessation
  • 1999-10-11 EP EP99950692A patent/EP1121242B1/fr not_active Expired - Lifetime
  • 1999-10-11 CA CA002347145A patent/CA2347145A1/fr not_active Abandoned
  • 1999-10-11 JP JP2000577021A patent/JP4511045B2/ja not_active Expired - Fee Related
  • 1999-10-11 RU RU2001113269/12A patent/RU2229383C2/ru not_active IP Right Cessation
  • 1999-10-11 WO PCT/EP1999/007599 patent/WO2000023260A1/fr not_active Ceased
  • 1999-10-11 AU AU63373/99A patent/AU751895B2/en not_active Ceased
  • 1999-10-11 DE DE69905269T patent/DE69905269T2/de not_active Expired - Lifetime
  • 1999-10-11 KR KR1020017004590A patent/KR100602406B1/ko not_active Expired - Fee Related
  • 1999-10-11 ES ES99950692T patent/ES2190662T3/es not_active Expired - Lifetime
  • 1999-10-11 CN CNB998120685A patent/CN1180928C/zh not_active Expired - Fee Related
• 2001
  • 2001-04-11 US US09/833,048 patent/US6461460B2/en not_active Expired - Lifetime

Patent Citations (4)

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