Process and apparatus for manufacturing tyres

Patent metadata

Field	Value
Publication number	US-10155351-B2
Application number	US-201514940906-A
Country	US
Kind code	B2
Filing date	Nov 13, 2015
Priority date	Jun 11, 2007
Publication date	Dec 18, 2018
Grant date	Dec 18, 2018

Abstract

A plurality of strip-like elements is applied onto a forming drum externally having a substantially cylindrical laying surface. The strip-like elements are disposed in mutually approached relationship to form at least one first annular reinforcing layer on the forming drum itself set to a first work diameter at which each of the applied strip-like elements on the laying surface subtends an arc of a circumference of a width as large as a submultiple integer of the overall circumferential extension of the laying surface itself. Adjustment devices operating on the forming drum subsequently carry out expansion of the latter to a second work diameter larger than the first work diameter, while maintaining its laying surface substantially cylindrical.

First claim

The invention claimed is:

1. An apparatus for producing tyres, comprising:
a forming drum externally having a substantially cylindrical laying surface;
a grip shank coaxially carried by the forming drum;
a manipulator configured for removably engaging the grip shank to drive the grip shank in rotation; and
adjustment devices configured to operate on the forming drum to selectively expand and contract said forming drum, while keeping a laying surface thereof substantially cylindrical, between a first work diameter and a second work diameter greater than the first work diameter, wherein the forming drum comprises consecutive circumferential sectors radially movable upon command of the adjustment devices,
the adjustment devices comprising:
at least one spiral cam fastened to the grip shank and engaging the circumferential sectors and drivable in rotation around a geometric axis of the forming drum to give rise to a radial movement of the circumferential sectors;
at least one guide flange rotatably supported with respect to the grip shank and the at least one spiral cam and slidably carrying the circumferential sectors;
locking devices configured to be selectively activated for locking the at least one guide flange relative to the grip shank, wherein the locking devices comprise:
a locking disc integral with the grip shank;
at least one latch integral with the at least one guide flange and engageable with the locking disc; and
an unlocking actuator carried by the manipulator;

wherein the at least one latch is operatively engageable with the unlocking actuator and operable for disengaging the grip shank from the at least one guide flange in a rotation direction while the at least one guide flange is retained by the unlocking actuator itself.

2. The apparatus as claimed in claim 1 , wherein said forming drum comprises an auxiliary drum operatively associated with a first feeding unit of a belt structure.

3. The apparatus as claimed in claim 1 , wherein said forming drum comprises a primary building drum operatively associated with a building station of a carcass structure.

4. The apparatus as claimed in claim 1 , further comprising:
a programmable control unit configured to:
store a first reference parameter corresponding to the first work diameter;
store a second reference parameter corresponding to the desired second work diameter; and
calculate a difference between said first and second reference parameters.

5. The apparatus as claimed in claim 4 , wherein said adjustment devices modulate an amount of radial expansion of the forming drum, as a function of a difference calculated by the programmable control unit.

6. The apparatus as claimed in claim 1 , further comprising devices configured to form at least one annular insert of elastomeric material around the laying surface.

7. The apparatus as claimed in claim 6 , wherein said devices configured to form the at least one annular insert comprise a distributor for delivering a continuous elongated element, and a motor for driving the forming drum in rotation.

8. The apparatus as claimed in claim 1 , wherein said adjustment devices operate on the forming drum to contract the forming drum to a diameter smaller than the first work diameter.

9. An apparatus as claimed in claim 1 , wherein said circumferential sectors, on the laying surface thereof have circumferential shoulders abutting against each other when the drum is set to a minimum diameter.

10. The apparatus as claimed in claim 1 , wherein each of said circumferential sectors has comb-like end portions each operatively engaging in a comb-like end surface complementary thereto, carried by a circumferentially adjacent circumferential sector.

11. The apparatus as claimed in claim 1 , further comprising at least one robotized arm capable of operatively engaging the forming drum at the grip shank.

12. The apparatus as claimed in claim 11 , wherein said manipulator is operatively carried by the robotized arm.

13. The apparatus as claimed in claim 1 , further comprising holding devices for strip-like elements applied to the forming drum.

14. The apparatus as claimed in claim 13 , wherein said holding devices comprise magnets associated with each circumferential sector.

15. The apparatus as claimed in claim 1 , wherein:
the locking disc carries circumferentially distributed fitting seats; and
the at least one latch comprises a block integral with the at least one guide flange and a pin elastically pushed towards the locking disc for engagement with the fitting seats.

Assignees

• Pirelli

Inventors

• Marchini Maurizio
• Amurri Cesare
• Mancini Gianni
• Lo Presti Gaetano

Classifications

• B29D30/24

  Drums · CPC title

• 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

• B29D30/305

  by feeding cut-to-length pieces in a direction parallel to the drum axis and placing the pieces side-by-side to form an annular element · CPC title

• B29D2030/2678

  by using magnets · CPC title

• B29D30/3028

  by feeding a continuous band and winding it helically, i.e. the band is fed while being advanced along the drum axis, to form an annular element (winding and joining, helically in general B29C53/58) · CPC title