Process and apparatus for manufacturing vehicle tires
AssigneeSocieta' Pneumatici Pirelli S.p.A.
InventorGiorgio Bertoldo
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Abstract
This invention provides a method and apparatus for making vehicle tires wherein the annular, reinforcing structure and the tread band are manufactured on two drums, one drum having a comb-shaped surface, and the other drum having sectors. The comb-shaped drum is co-axial and can be slipped off with respect to the drum having sectors. Means are provided for rotating the two drums independently of one another in a slipped position, and for centering the teeth of the comb when the two drums are one around the other. After centering, the sectors are expanded, from the inside towards the outside of the comb, for sustaining the annular structure previously disposed on the comb in a slipped position from the sectors and for receiving the tread band.
Claims10
In a process for manufacturing tires which comprise a carcass, an annular reinforcing structure, and a tread-band which process comprises the steps of:
- (a) preparing a carcass of a first tire in a cylindrical form on a first expandable drum;
- (a) building an annular reinforcing structure for the first tire on a hollow drum having a comb-shaped surface;
- (c) expanding the sectors of a second expandable drum, between void spaces of the comb, from an inner position to an outer position of the comb, thereby shaping and supporting the annular reinforcing structure only with the sectors;
- (d) slipping the comb-shaped drum from the drum-with-sectors;
- (e) applying a tread-band on the annular structure while it is supported by the sectors of the second drum;
- (f) transferring the annular reinforcing structure and the tread-band from the second to the first expandable drum;
- (g) expanding the first expandable drum to impart a final toroidal shape to the tire;
- and
- (h) removing said tire from said first expandable drum;
- the improvement which comprises the additional steps of
- (i) building the annular reinforcing structure of a second tire on the comb-shaped drum in a slipped position from the sectors after step (d);
- preparing a carcass of a second tire in a cylindrical form on said first expandable drum after completion of step (h);
- (j) transferring, after step (f), the annular reinforcing structure of the second tire while supported by the comb-shaped drum around the sectors of the second drum;
- and
- (k) repeating steps (c) to (h).
In an apparatus for making a vehicle tire having a carcass, a tread band, and an annular reinforcing structure disposed between the carcass and the tread band, said apparatus comprising a building drum, axially separable into two distinct parts and recomposable into an assembled unity, for manufacturing and shaping said annular reinforcing structure and for assembling it with said tread band, said two distinct parts being respectively constituted by a first cylindrical, hollow, comb-shaped drum (11'), for manufacturing said annular structure, and by a second expandable drum (11) with sectors (13), for shaping the annular structure and for supporting said shaped annular structure during its assembling with the tread band, said comb-shaped drum having its teeth (14) off-set with the sectors of the expandable drum when said building drum is in the state of assembled unity, the sectors of said second drum being radially expandable through the void spaces in between the teeth of the comb-shaped drum from inside towards the outside of said comb, said apparatus also comprising means to axially slide said comb-shaped drum from and towards said expandable drum, bringing said two drums alternatively axially separated, in a position of no mutual interference, and joined together in assembled unity,
- the improvement wherein means are provided for allowing and for causing the comb-shaped drum to rotate independently in direction and speed with respect to the expandable drum, and centering means for aligning the teeth of said comb-shaped drum in off-set relationship with the sectors of the expandable drum, all said means acting when said drums are axially separated from each other.
Dependencies are inferred from the claim text.