Process and apparatus for manufacturing pneumatic tyres for vehicle wheels

Patent metadata

Field	Value
Publication number	US-9724886-B2
Application number	US-201214009910-A
Country	US
Kind code	B2
Filing date	Apr 18, 2012
Priority date	Apr 29, 2011
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

In a process for building tires for vehicle wheels, a carcass sleeve is arranged on a shaping drum including two half-drums and two supports. Each support is operatively associated with one of the half-drums and carries a plurality of turning-up levers having free ends positioned close to the respective half-drum. Two annular anchoring structures are disposed around the carcass sleeve and each of the two supports is locked to the respective half-drum by interposing only stiff mechanical elements in mutual contact between the support and the half-drum. The carcass sleeve is shaped in a toroidal conformation, by setting a threaded shaft in rotation and moving the half-drums dose to each other. Subsequently, each of the two supports is unlocked from the respective half-drum and the threaded shaft is set in rotation to move each support close to the respective half-drum and lift up the free ends of the turning-up levers until the end flaps of the carcass sleeve are turned up around the annular anchoring structures.

First claim

The invention claimed is:

1. A process for building a tyre for vehicle wheels, comprising:
arranging a carcass sleeve comprising a carcass ply on a shaping drum comprising first and second half drums, first and second supports, and first and second sets of guide rods, the first support being operatively associated with the first half-drum, the second support being operatively associated with the second half-drum, the first set of guide rods having first ends integral with the first half-drum, the second set of guide rods having first ends integral with the second half-drum, and each support carrying a plurality of turning-up levers having free ends positioned close to its respective half-drum, wherein the carcass sleeve disposed on the first and second half-drums covers at least said free ends;
arranging two annular anchoring structures around the carcass sleeve;
locking each of the first and second supports relative to its associated half-drum by moving a flange mounted on the respective support to an engagement position in which second ends of the set of guide rods integral with the associated half-drum are locked in openings of said flange, wherein the first and second sets of guide rods are interposed respectively between said first and second supports and their associated half-drums;
setting a threaded shaft in rotation for giving a toroidal conformation to the carcass sleeve while forces urging each half-drum towards its associated support are borne entirely by the locked guide rods;
unlocking each support from its associated half-drum; and
setting said threaded shaft in rotation for lifting the free ends of said turning-up levers until turning up end flaps of the carcass sleeve around the annular anchoring structures.

2. The process as claimed in claim 1 , wherein the unlocking of each support relative to its associated half-drum comprises:
leaving said guide rods free to slide through their associated support.

3. The process as claimed in claim 2 , wherein the unlocking of each support relative to its associated half-drum comprises:
moving the flange mounted on each support to a disengaged position, in which the second ends of the rods are free to pass through openings of said flange.

4. The process as claimed in claim 1 , wherein before the step of setting said threaded shaft in rotation for lifting the free ends of said turning-up levers, each half-drum is hooked to a spacer separating the first half-drum from the second half-drum of the shaping drum, wherein the spacer is mounted on a shaft carrying said half-drums.

5. The process as claimed in claim 4 , comprising:
replacing the spacer with another different spacer for building a different tyre.

6. The process as claimed in claim 1 , comprising positioning of each of said annular anchoring structures in correspondence with an annular retaining seat of a respective one of the half-drums.

7. The process as claimed in claim 6 , wherein said positioning of the annular anchoring structures comprises:
radially expanding a plurality of axially internal sectors and a plurality of axially external sectors of each half-drum so as to delimit each annular retaining seat until receiving its annular anchoring structure.

8. The process as claimed in claim 7 , wherein, during the radial expansion of the axially external sectors, the free ends of the turning-up levers rest on tailpieces of said axially external sectors and follow radial expansion movement thereof.

9. The process as claimed in claim 7 , wherein, in a starting action of moving each support close to its associated half-drum, the free ends of the turning-up levers traverse an inclined surface carried by the axially external sectors.

10. The process as claimed in claim 1 , comprising:
arranging a crown structure around the carcass sleeve disposed on the shaping drum, wherein, during the step of giving the toroidal conformation to the carcass sleeve, a radially external portion of the carcass sleeve is brought against the crown structure.

11. The process as claimed in claim 1 , wherein said threaded shaft carries two lead screw nuts each rigidly connected to a respective one of the supports, for moving the half-drums along an axial direction with respect to the shaping drum during said step of giving the toroidal conformation to the carcass sleeve.

12. The process as claimed in claim 1 , wherein said rotation of said threaded shaft for lifting the free ends of said turning-up levers moves each support close to its associated half-drum along an axial direction with respect to shaping drum.

Assignees

• Bignogno Mauro
• Portinari Gianni
• Dale′ Pietro
• Pirelli

Inventors

• Bignogno Mauro
• Portinari Gianni
• Dale′ Pietro

Classifications

• B29D30/245

  Drums for the single stage building process, i.e. the building-up of the cylindrical carcass and the toroidal expansion of it are realised on the same drum (expansion to a toroidal shape B29D30/36) · CPC title

• B29D2030/3264

  using radially expandable, contractible mechanical means, e.g. circumferentially spaced arms, spring rollers, cages · CPC title

• B29D30/36

  Expansion of tyres in a flat form {, i.e. expansion to a toroidal shape independently of their building-up process}, e.g. of tyres built by the flat-tyres method or by jointly covering two bead-rings · CPC title

• B29D2030/3257

  using pressing rollers · CPC title

• B29D30/12 Primary

  Cores · CPC title