Tire curing bladder

• US 20060040006A1
• Filed: 08/23/2004
• Published: 02/23/2006
• Est. Priority Date: 08/23/2004
• Status: Active Grant

• Current Assignee: Goodyear Tire & Rubber Company
• Original Assignee: Goodyear Tire & Rubber Company
• Inventors: Wang, Yang, Lee, Ching-Chih, Ashton, Susan Lynn, Quijano, Alfonso, Okoye, Ikechukwu Joel
• Granted Patent: US 7,144,236 B2
• Time in Patent Office: Days
• US Class Current: 425/52
• CPC Class Codes: B29C 43/3642 Bags, bleeder sheets or cauls for isostatic pressing
• CPC Class Codes: B29D 2030/0655 Constructional or chemical features of the flexible cores
• CPC Class Codes: B29D 30/0654 Flexible cores therefor, e.g. bladders, bags, membranes, diaphragms elastic cores or mandrels for shaping of plastics B29C33/505; bags for isostatic pressing in compression moulding B29C43/12, B29C43/3642

Abstract

An expandable bladder for shaping a pneumatic tire to be mounted inside a tire curing press has a pair of opposing annular beads and an expansion portion located between the pair of annular beads. The expansion portion of the bladder has a central portion, shoulder portions, and sidewall portions. When the bladder is in a mounted but uninflated mode, the shoulder portions have a radius of curvature less than infinity. At a distance (x) from each end of the central portion, the bladder has an increased thickness in the shoulder and upper sidewall portions.

Claims

1. An expandable bladder for shaping a pneumatic tire to be mounted inside a tire curing machine, the expandable bladder having a toroidal configuration and comprising

a pair of opposing annular beads and an expansion portion located between the pair of annular beads, the expansion portion comprising a central portion, shoulder portions, and sidewall portions,

wherein, when the bladder is in a mounted but uninflated mode, the bladder being characterized by:

at a distance (x) from each end of the central portion, the bladder increases in thickness towards the annular beads.

2. The bladder of claim 1 wherein the distance (x) has a width of at least 5% of the width (F) of the central portion.

3. The bladder of claim 1 wherein the distance (x) has a width of 15-30% of the width (F) of the central portion.

4. The bladder of claim 1 wherein the ratio of the bladder thickness at the mid-section Wm to the bladder thickness at central portion is greater than 1.05.

5. The bladder of claim 1 wherein the ratio of the bladder thickness at the mid-section Wm to the bladder thickness at central portion is in the range of 1.20 to 1.40.

6. The bladder of claim 1 wherein the central portion has a constant thickness.

7. The bladder of claim 1 wherein the shoulder and the upper portion of the sidewall portion have a localized increased thickness in comparison to the central portion of the bladder.

8. The bladder of claim 7 wherein the maximum thickness of the bladder in the shoulder and upper portion of the sidewall portion has a thickness value of at least 1.05 times the thickness of the central portion of the bladder.

9. The bladder of claim 8 wherein the maximum thickness of the bladder in the shoulder and upper portion of the sidewall portion has a thickness value of at 1.20 to 1.75 times the thickness of the central portion of the bladder.