← Back to Patent Explorer
US4288265A Expired / Lapsed US ⏱️ 0.0 years remaining

Process and apparatus for manufacturing radial tires

Assignee: Industrie Pirelli SpA
•
Filing: 1979-09-18
•
Granted: 1981-09-08
•
Expires: 1999-09-18
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A process is provided for manufacturing radial tires for a motor vehicle having a radial carcass, a reinforcing structure with at least two layers of criss-crossed symmetrically arranged metallic cords forming a belt, and a tread. The process involves a series of steps which comprise: building up a carcass in a cylindrical configuration on a first expandable building drum and shaping the carcass into a toroidal configuration. A reinforcing belt is also formed by winding two layers of metallic cords on an auxiliary expandable drum with a diameter equal to the external diameter of the toroidal shaped carcass. The belt is maintained in slidable contact on the drum and shaped toroidally by expanding the auxiliary drum. The belt is then removed from the auxiliary drum and transferred with a tread band to the carcass on the first drum. The carcass is toroidal shaped again to assemble the carcass and belt. The assembly is vulcanized under pressure in a mold.

Inventors

  • 👤 Antonio Pacciarini
  • 👤 Giorgio Bertoldo

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 08:44
CPC Classifications
B; B29; B29D; B29D23/00; B29D23/001; B29D30/00; B29D30/06; B29D30/08; B29D30/20; B29D30/24; B29D30/26; B29D30/2607; B29D30/70; B29K; B29K2021/00; Y; Y10; Y10T; Y10T152/00; Y10T152/10; Y10T152/10495; Y10T152/10765

Claims Analysis

Total Claims: 28
Claim 1
Independent Claim 291 words
In a process for manufacturing radial tires for a motor vehicle having a radial carcass, a reinforcing structure with at least two layers of metallic cords forming a belt, the cords of adjacent layers being criss-crossed with respect to each other, and symmetrically oriented with respect to the longitudinal direction of the tire, and a tread, the said process comprising the steps of: (a) building-up a carcass in a cylindrical configuration, on an expandable main tire building-drum; (b) shaping the said carcass in its non-vulcanized state, into a toroidal configuration, (c) winding two layers of metallic cords on an auxialiary drum having an expandable part and a diameter equal to the external diameter of the carcass after the toroidal configuration (b) thereof on the main building-drum to form a cylindrically shaped belt; (d) expanding the expandable part of the said auxiliary drum, and maintaining the said belt in a slidable condition on said expandable part of the auxilliary drum, converting the belt from its first cylindrical configuration to a toroidal configuration with an equatorial development which is larger than the equatorial development of the carcass after the shaping step (b); (e) winding an elastomeric band from which a tread band is formed on the toroidal shaped belt formed in (d); (f) contracting the auxiliary drum; (g) removing from the contracted auxiliary drum, the annular layered-band comprising the belt and the tread band, (h) transferring and centering said annular layered-band with the equatorial plane of the carcass on the main drum; (i) expanding the main drum, and shaping the carcass into a second toroidal configuration until the carcass crown is brought into contact with the corresponding toroidal surface of the belt; and (j) vulcanizing the so-formed tire in a mold under pressure.
Claim 2
Dependent Claim 291 words
In a process for manufacturing radial tires for a motor vehicle having a radial carcass, a reinforcing structure with at least two layers of metallic cords forming a belt, the cords of adjacent layers being criss-crossed with respect to each other, and symmetrically oriented with respect to the longitudinal direction of the tire, and a tread, the said process comprising the steps of: (a) building-up a carcass in a cylindrical configuration, on an expandable main tire building-drum; (b) shaping the said carcass in its non-vulcanized state, into a toroidal configuration, (c) winding two layers of metallic cords on an auxialiary drum having an expandable part and a diameter equal to the external diameter of the carcass after the toroidal configuration (b) thereof on the main building-drum to form a cylindrically shaped belt; (d) expanding the expandable part of the said auxiliary drum, and maintaining the said belt in a slidable condition on said expandable part of the auxilliary drum, converting the belt from its first cylindrical configuration to a toroidal configuration with an equatorial development which is larger than the equatorial development of the carcass after the shaping step (b); (e) winding an elastomeric band from which a tread band is formed on the toroidal shaped belt formed in (d); (f) contracting the auxiliary drum; (g) removing from the contracted auxiliary drum, the annular layered-band comprising the belt and the tread band, (h) transferring and centering said annular layered-band with the equatorial plane of the carcass on the main drum; (i) expanding the main drum, and shaping the carcass into a second toroidal configuration until the carcass crown is brought into contact with the corresponding toroidal surface of the belt; and (j) vulcanizing the so-formed tire in a mold under pressure.
Claim 3
Dependent Claim 152 words
A drum for separately shaping a reinforcing belt and a tread band for assembly with a radial carcass in the manufacture of a tire for a motor vehicle, said drum comprising means for expansion thereof and for transforming said belt from a cylindrical configuration into a toroidal configuration, said means having a surface over which said belt will slide when transformed from a cylindrical configuration into a toroidal configuration, said means comprising a plurality of comb shaped support members disposed circumferentially and parallel to the drum axis with void spaces interposed therebetween, a plurality of convex sectors with a total convex surface disposed below the upper surface of said support members in the cylindrical configuration of the said drum, and means for passing the sectors between the said void spaces and for expanding the sectors to a position above the said support members for imparting a toroidal configuration to the auxiliary drum.
Claim 4
Dependent Claim 152 words
A drum for separately shaping a reinforcing belt and a tread band for assembly with a radial carcass in the manufacture of a tire for a motor vehicle, said drum comprising means for expansion thereof and for transforming said belt from a cylindrical configuration into a toroidal configuration, said means having a surface over which said belt will slide when transformed from a cylindrical configuration into a toroidal configuration, said means comprising a plurality of comb shaped support members disposed circumferentially and parallel to the drum axis with void spaces interposed therebetween, a plurality of convex sectors with a total convex surface disposed below the upper surface of said support members in the cylindrical configuration of the said drum, and means for passing the sectors between the said void spaces and for expanding the sectors to a position above the said support members for imparting a toroidal configuration to the auxiliary drum.
Claim 5
Dependent Claim 24 words
The drum of claim 2 wherein said surface of said means for expansion has a coefficient of friction equal to that of a metal.
Claim 6
Dependent Claim 80 words
The process of claim 1 comprising after the step of expanding the auxiliary drum, the further successive step of applying and winding on the already expanded belt, at least one layer of cords which are parallel to each other and disposed in the longitudinal direction, said cords being comprised of a metallic or textile material that shrinks in length when heated, and finally winding the tread for originating the annular layered-band that has to be transferred to the main drum.
Claim 7
Dependent Claim 46 words
The process, of claim 1 or 4 comprising the step of centering the belt on the auxiliary drum by winding the belt in a cylindrical configuration while maintaining one side in contract with a circular ridge adapted to act as a reference on the auxiliary drum.
Claim 8
Dependent Claim 22 words
The process of claim 1 or 4 comprising the step of stitching the belt with a synthetic thread before expanding the belt.
Claim 9
Dependent Claim 116 words
The auxiliary drum of claim 2 wherein said means adapted for assuming a configuration and for making the auxiliary drum pass from a cylindrical configuration to a toroidal one comprises a plurality of supports disposed circumferentially and parallel to the drum axis with void spaces interposed therebetween, a plurality of convexed sectors comprising the expandable part of the said means with a total convexed surface disposed below the upper surface of said supports in the cylindrical configuration of the auxiliary drum, means for the passage of the sectors between the said void spaces and for the expansion of the sectors to a position above the said supports for determining the toroidal configuration of the auxiliary drum.
Claim 10
Dependent Claim 16 words
The auxiliary drum of claim 7, wherein said plurality of supports constitutes a comb-shaped supporting structure.
Claim 11
Dependent Claim 120 words
The auxiliary drum of claim 8, wherein the said expandable convexed sectors disposed below the comb-shaped supports comprise on the convexed part, longitudinal wells corresponding to the comb's teeth, each said well having a depth measured radially to the drum between the innermost surface of the tooth and the bottom of the relative well in its at-rest position at least equal to the radial shifting of the sectors for passing from the first position below the comb, to the upper position that is coincedent with the toroidal configuration of the auxiliary drum wherein the comb is lodged in the said wells and axially extractable from the wells in the absence of contact with the extremities of the already expanded belt.
Claim 12
Dependent Claim 29 words
The auxiliary drum of claim 8 or 9 wherein said comb constitutes at least one-half of the total cylindrical surface corresponding to the cylindrical configuration of the auxiliary drum.
Claim 13
Dependent Claim 25 words
The auxiliary drum of claim 7, 8, or 9 wherein the sectors are made of steel or of aluminium, at least in the upper convexed-surface.
Claim 14
Dependent Claim 22 words
The auxiliary drum of claim 7, 8 or 9, characterized by the fact that the sectors comprise scoring on the convex surface.
Claim 15
Dependent Claim 121 words
The auxiliary drum of claim 7 wherein the said means for the radial expansion of the sectors, comprise for each sector two levers, a pilot shaft, and an actuating mechanism, said levers being criss-crossed over each other, with the first ends hinged to the ends of the sector, and the second ends associated with fluid-dynamic pistons of the said mechanism, said pistons being slidable in a direction parallel to the auxiliary drum axis, said pilot shaft that is extended in a direction radial to the drum, comprising an upper-end rigidly connected to the center of the sector and a lower-end that is slidable in a bushing of the drum and controllable blocking means for limiting the radial shifting of the sectors.
Claim 16
Dependent Claim 85 words
The auxiliary drum of claim 13, wherein the said blocking means comprise a screw, the ends of which are threaded in opposite directions, said screw being threadably fixed in corresponding threaded surface associated with the lower extremities of the levers, and in such a way that the rotation of the said screw in one direction or the other, transforms the initial reciprocal distance of the lower ends of the said levers, and the subsequent path of the pistons varies the expansion range of the sectors.
Claim 17
Dependent Claim 20 words
The auxiliary drum of claim 7 comprising sliding means for said plurality of supports, with respect to the said sectors.
Claim 18
Dependent Claim 97 words
The auxiliary drum of claim 15, wherein said sliding means comprise a plurality of horizontal guide-bars connected to a first and a second plate co-axial to the auxiliary drum, a third plate mounted to slide on the guide-bars, a fluid-dynamic command connected to an appropriate fixed framework of the drum, and with the rod of it connected to the third plate through the interposition of bearings adapted for rotating on corresponding rolling tracks made directly on parts fixed to the third plate, and with the rod, said third mobile plate being fixed to said plurality of supports.
Claim 19
Dependent Claim 31 words
The auxiliary drum of claim 2 comprising means for temporarily blocking under pressure the belt in the winding step onto the auxiliary drum, said means being disposed between the said supports.
Claim 20
Dependent Claim 28 words
An auxiliary drum, as in claim 17 wherein said means for associating the belt under pressure comprise further supports for the belt made out of a magnetic material.
Claim 21
Dependent Claim 22 words
The auxiliary drum, of claim 2 comprising means for centering the belt that is being wound onto the auxiliary drum in rotation.
Claim 22
Dependent Claim 27 words
An auxiliary drum, as in claim 19, wherein said means comprise a circular ridge defined substantially on a plane orthogonal to the axis of the auxiliary drum.
Claim 23
Dependent Claim 169 words
A plant for manufacturing radial tires, comprising a radial carcass, a reinforcing structure comprised by at least two layers of metallic cords criss-crossed one with the other for forming the belt and the tread, said plant being characterized by the fact of comprising a main expandable tire building drum for shaping the carcass from a cylindrical configuration to a first toroidal shape, and then to a subsequent toroidal shape having a higher value than the first shape, said auxiliary expandable drum having the structure of claim 25 and being adapted for changing a configuration from cylindrical to toroidal, for changing the said layers of metallic cords from a cylindrical configuration to a toroidal one corresponding to the configuration of the second shaping of the carcass, means for transferring the annular layered-band that is comprised by the reinforcing structure and by the tread, from said auxiliary drum onto said main drum after the first toroidal shaping of the carcass and prior to the second toroidal shaping of the same carcass.
Claim 24
Dependent Claim 34 words
A plant, as in claim 21, wherein said means for transferring said annular layered-band, comprise a ring having devices adapted for maintaining the annular layered-band in contact with the surface of the ring itself.
Claim 25
Dependent Claim 14 words
A plant, as in claim 22, wherein said devices of the ring are sectors.
Claim 26
Dependent Claim 28 words
A plant, as in claim 22, characterized by the fact that, the axes of the main drum, of the ring, and of the auxiliary drum, are all aligned.
Claim 27
Dependent Claim 257 words
In a process for manufacturing tires for a motor vehicle having a carcass, a reinforcing structure with metallic cords forming a belt, and a tread, the improvement which comprises (a) building-up a carcass in a cylindrical configuration, on an expandable main tire building-drum; (b) shaping the said carcass in its non-vulcanized state, into a toroidal configuration, (c) winding metallic cords on an auxilliary drum having an expandable part and a diameter which is equal to the external diameter of the carcass after the toroidal configuration from step (b) on the main building-drum to form a cylindrically shaped belt; (d) expanding the expandable part of the said auxiliary drum, and maintaining the said belt in a slidable condition on said expandable part of the auxilliary drum, converting the belt from its first cylindrical configuration to a toroidal configuration with an equatorial development which is larger than the equatorial development of the carcass after the shaping step (b); (e) winding an elastomeric band from which a tread band is formed on the toroidal shaped belt formed in (d); (f) contracting the auxiliary drum; (g) removing from the contracted auxiliary drum, the annular layered-band comprising the belt and the tread band, (h) transferring and centering said annular layered-band with the equatorial plane of the carcass on the main drum; (i) expanding the main drum, and shaping the carcass into a second toroidal configuration until the carcass crown is brought into contact with the corresponding toroidal surface of the belt; and (j) vulcanizing the so-formed tire in a mold under pressure.
Claim 28
Dependent Claim 257 words
In a process for manufacturing tires for a motor vehicle having a carcass, a reinforcing structure with metallic cords forming a belt, and a tread, the improvement which comprises (a) building-up a carcass in a cylindrical configuration, on an expandable main tire building-drum; (b) shaping the said carcass in its non-vulcanized state, into a toroidal configuration, (c) winding metallic cords on an auxilliary drum having an expandable part and a diameter which is equal to the external diameter of the carcass after the toroidal configuration from step (b) on the main building-drum to form a cylindrically shaped belt; (d) expanding the expandable part of the said auxiliary drum, and maintaining the said belt in a slidable condition on said expandable part of the auxilliary drum, converting the belt from its first cylindrical configuration to a toroidal configuration with an equatorial development which is larger than the equatorial development of the carcass after the shaping step (b); (e) winding an elastomeric band from which a tread band is formed on the toroidal shaped belt formed in (d); (f) contracting the auxiliary drum; (g) removing from the contracted auxiliary drum, the annular layered-band comprising the belt and the tread band, (h) transferring and centering said annular layered-band with the equatorial plane of the carcass on the main drum; (i) expanding the main drum, and shaping the carcass into a second toroidal configuration until the carcass crown is brought into contact with the corresponding toroidal surface of the belt; and (j) vulcanizing the so-formed tire in a mold under pressure.

References Cited (Backward Citations)

US3151013A Cited
US3374131A Cited
US3219510A Cited
US3713929A Cited
US3784437A Cited
US3925141A Cited
GB1509606A Cited
US4072550A Cited
US4131402A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-09-07 1985-03-09 1985-09-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-09-07 1989-03-09 1989-09-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-09-07 1993-03-09 1993-09-08 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag