Extendable curing press center post

• US 20020153638A1
• Filed: 04/17/2002
• Published: 10/24/2002
• Est. Priority Date: 04/18/2001
• Status: Active Grant

• Current Assignee: Pirelli Tyre SPA (Pirelli & C SPA)
• Original Assignee: Pirelli Tyre SPA (Pirelli & C SPA)
• Inventors: Yu, Wei
• Granted Patent: US 6,733,712 B2
• Time in Patent Office: Days
• US Class Current: 264/315
• CPC Class Codes: B29D 30/0645 Devices for inserting vulcanising cores, i.e. bladders, into the tyres; Closing the press in combination herewith

Abstract

A center post assembly for a tire curing press comprising a center post having a upper component disposed above a lower component. The upper component is movable between a first position wherein the upper component is adjacent to the lower component and a second position wherein the upper component is axially displaced away from the lower component and substantially adjacent to an upper bead of a green tire assembly. The center post assembly further includes a bladder sealingly clamped to the upper and lower components. The bladder is in fluid communication with a fluid supply. The upper component moves between said first and second positions due to expansion of the bladder caused by introduction of fluid into the bladder from the fluid supply allowing the bladder to evenly disperse on the inner surface of the green tire assembly substantially reducing the risk of the bladder being damaged by the mold as it closes.

Claims

1. A center post assembly for a tire curing press comprising:

a center post having an upper component disposed above a lower component, said upper component being movable between a first position wherein said upper component is adjacent to said lower component and a second position wherein said upper component is axially displaced away from said lower component and substantially adjacent to an upper bead of a green tire assembly;

a bladder sealingly clamped to said upper and lower components, said bladder in fluid communication with a fluid supply; and

,

said upper component being movable between said first and second positions by expansion of said bladder caused by introduction of fluid into said bladder from the fluid supply.

2. The center post assembly of claim 1 further comprising:

a first clamp ring attached to said upper component;

a second clamp ring attached to said lower component; and

,

said bladder sealingly clamped to said upper and lower component by said first and second clamp rings.

3. The center post assembly of claim 1 wherein said lower component has a shape and said upper component includes a cavity in a bottom surface thereof corresponding to the shape of said lower component so that at least a portion of said lower component slidingly engages said cavity.

4. The center post assembly of claim 3 wherein said upper component further comprises a stop mechanism that limits the upward travel of said upper component.

5. The center post assembly of claim 4 wherein said lower component is hollow and includes an opening on an upper surface thereof having a smaller diameter than an inner diameter of said lower component and said stop mechanism comprises a rod extending from an upper surface of said cavity and slidingly engaging said opening.

6. The center post assembly of claim 5 wherein said stop mechanism further comprises a protuberance extending radially from a lower end of said rod having a diameter greater than said opening and less than the inner diameter of the lower component, said protuberance limiting upward motion upon contact with a lip created by said opening.

7. The center post assembly of claim 6 wherein said stop mechanism limits travel of said upper component to a distance less than or equal to a depth of said cavity.

8. The center post assembly of claim 3 wherein said lower component further comprises a stepped surface corresponding to a lower edge of said upper component to provide a substantially uniform profile along the length of said center post when said upper component is located in said first position to reduce wear on said bladder.

9. The center post assembly of claim 3 wherein said lower component includes at least one key extending axially upward on an outer surface of said upper component for engaging at least one corresponding key slots on a lower end of the upper component.

10. The center post assembly of claim 2 further comprising an upper mold ring situated above said first clamp ring and a tire mold, said tire mold including a surface corresponding with said upper mold ring.

11. The center post assembly of claim 2 further comprising a cap attached at an upper end of said upper component for engaging a tire mold.

12. The center post assembly of claim 11 further comprising a spacer situated between said cap and the upper end of said upper component for determining the height of said center post.

13. The center post assembly of claim 12 wherein said first clamp ring is attached to said cap.

15. The tire curing press of claim 14 further wherein the center post assembly further comprises

a first clamp ring attached to said upper component;

a second clamp ring attached to said lower component; and

,

said bladder sealingly clamped to said upper and lower component by said first and second clamp rings.

16. The tire curing press of claim 14 further wherein said lower component has a shape and said upper component includes a cavity in a bottom surface thereof corresponding to the shape of said lower component so that at least a portion of said lower component slidingly engages said cavity.

18. The method of manufacture of a tire of claim 17 further comprising the steps of:

attaching a first clamp ring to said upper component;

attaching a second clamp ring to said lower component; and

,

sealingly clamping said bladder clamped to said upper and lower component by said first and second clamp rings.

19. The method of manufacture of a tire of claim 17 further comprising the steps of:

slidingly engaging a cavity with at least a portion of said lower component wherein said lower component has a shape and said upper component includes in a bottom surface thereof corresponding to the shape of said lower component.

14. A tire curing press comprising:

a mold; and

a center post assembly for a tire curing press further comprising

a center post having a upper component disposed above a lower component, said upper component being movable between a first position wherein said upper component is adjacent to said lower component and a second position wherein said upper component is axially displaced away from said lower component and substantially adjacent to an upper bead of a green tire assembly;

a bladder sealingly clamped to said upper and lower components, said bladder in fluid communication with a fluid supply; and

,

said upper component being movable between said first and second positions by expansion of said bladder caused by introduction of fluid into said bladder from the fluid supply.

17. The method of manufacture of a tire comprising the steps of:

providing a green tire carcass;

providing a bladder

providing a center post having an upper component disposed above a lower component,

said upper component being movable between a first position wherein said upper component is adjacent to said lower component and a second position wherein said upper component is axially displaced away from said lower component and substantially adjacent to an upper bead of a green tire assembly;

sealingly clamping a bladder to said upper and lower components, said bladder in fluid communication with a fluid supply; and

,

introducing a fluid into said a bladder from the fluid supply causing said upper component being movable between said first and second positions by expansion of said bladder.