Bladder for vulcanizer, vulcanizer using the same and vulcanizing-molding method

• US 6,551,085 B1
• Filed: 05/12/2000
• Issued: 04/22/2003
• Est. Priority Date: 05/12/1999
• Status: Expired due to Fees

• Current Assignee: Klaus Schmidt
• Original Assignee: Kobe Steel Limited
• Inventors: Sakurai, Akira, Okada, Kazuto, Fujieda, Yasuhiko, Mitamura, Hisashi, Fujisawa, Kazuhisa, Fukumoto, Hirohiko
• Primary Examiner(s): Vargot, Mathieu D.
• Application Number:
  US09/570,345
• Time in Patent Office: 1,075 Days
• Field of Search: 264/315, 264/326, 264/404, 156/416, 425/51, 425/52, 425/41, 425/35, 425/43, 249/65
• US Class Current: 425/35
• CPC Class Codes: B29C 2035/0211 resistance heating B29C2035/0811 takes precedence
• CPC Class Codes: B29C 2035/0811 using induction
• CPC Class Codes: B29C 33/50 elastic or flexible for isostatic pressing B29C43/3642
• CPC Class Codes: B29C 43/104 the mould cavity lying totally outside the axis of symmetry, e.g. toroidal moulds
• CPC Class Codes: B29C 43/3642 Bags, bleeder sheets or cauls for isostatic pressing
• CPC Class Codes: B29D 2030/0674 Heating by using non-fluid means, e.g. electrical heating
• CPC Class Codes: B29D 30/0601 Vulcanising tyres; Vulcanising presses for tyres
• CPC Class Codes: B29K 2105/203 Magnetic parts
• CPC Class Codes: B29L 2030/00 Pneumatic or solid tyres or parts thereof conveyor belts B29L2031/7092; drive belts B29L2031/7094; fourdrinier belts B29L2031/733
• CPC Class Codes: B30B 5/02 wherein the pressing means is in the form of a flexible element, e.g. diaphragm, urged by fluid pressure

Abstract

A bladder for a vulcanizer includes, as a constituent member, a low elongation material with stable properties at vulcanization temperatures. During a vulcanization-molding process, the bladder is pressed against the inner surface of a green tire using a pressurized medium. The pressurized medium can be at vulcanization temperatures. The bladder has substantially the same shape as the inner wall surface of the tire that is formed using the bladder. As a result, irregularities in the shape of the inner wall surface of a tire rarely occur, and the frequency of exchange of bladders can be reduced. The vulcanizer bladder can include a conductive material or a magnetic material, both of which can be heated by using an induction heating coil. The use of both heat from the pressurized medium and heat generated in the bladder to vulcanize a green tire can shorten the period of time required for vulcanizing-molding.

Claims

1. In a vulcanizer having a mold for defining a shape of an outer wall of a tire after vulcanizing-molding, a vulcanizer bladder for pressing an inner wall of a green tire towards the mold during vulcanizing-molding, the vulcanizer bladder comprising:

a knitted or woven low elongation material with stable properties at vulcanizing-molding temperatures, wherein the low elongation material has an elongation at 200°

C. in a range of 5%-15%, and wherein

the vulcanizer bladder, at rest, has substantially the same shape as the inner wall of the tire after the vulcanizing-molding.

2. The vulcanizer bladder according to claim 1, wherein

the knitted or woven low elongation material comprises at least one of organic fibers including material selected from the group consisting of nylons, polyesters, aramids, polyparaphenylene benzo-bis-oxazol (PBO), and polyphenylene sulfides;

inorganic fibers selected from the group consisting of glass fibers and carbon fibers;

metal cord material;

carbon-containing fiber;

metal-coated fiber; and

resin-coated fiber.

3. The vulcanizer bladder according to claim 1, wherein the low elongation material is impregnated or coated with

at least one elastomer and

a resin selected from the group consisting of fluoride resins and silicone resins.

4. The vulcanizer bladder according to claim 1, further comprising a conductive material.

5. The vulcanizer bladder according to claim 4, wherein the conductive material comprises at least one selected from the group consisting of conductive rubber, conductive fiber, conductive resin, metal cord material and a heat generating coil.

6. The vulcanizer bladder according to claim 1, further comprising a magnetic material.