VULCANIZING PRESS INTENDED FOR CURING RADIAL TIRES BY MEANS OF A BLADDER OF TOROIDAL SHAPE

• US 3,837,770 A
• Filed: 09/28/1972
• Issued: 09/24/1974
• Est. Priority Date: 09/28/1971
• Status: Expired due to Term

• Current Assignee: Georges Gazuit
• Original Assignee: Georges Gazuit
• Inventors: Gazuit, Georges
• Primary Examiner(s): Flint, Jr., J. Howard
• Application Number:
  US05/293,089
• Time in Patent Office: 726 Days
• Field of Search: 425/33,32,29,36,39,52,23
• US Class Current: 425/33
• CPC Class Codes: B29D 2030/0655 Constructional or chemical features of the flexible cores
• CPC Class Codes: B29D 30/0645 Devices for inserting vulcanising cores, i.e. bladders, into the tyres; Closing the press in combination herewith
• 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
• 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

Abstract

This bladder is a piece of rubber or other air-impervious plastic material which is adapted to be introduced into the crude tires fitted in vulcanizing presses to constitute the internal element of the mould in which the tire is to be cured. This bladder is of substantially toroidal configuration, has a constant thickness and dimensions approaching very closely the internal dimensions of the crude tire to be cured, and comprises two beads of same diameter and same axial direction. This bladder is intended more particularly for use in presses designed for vulcanizing radial ply tires.

Claims

1. Vulcanizing press intended for curing crude radial tires by means of a bladder of toroidal shape having two beads of same diameter secured to the outer periphery of a pair of parallel coaxial flanges driven by means of an axial shaft, said press comprising a cylindrical socket secured to the underface of the upper flange and formed with an integral ring at its base, a sleeve rigid with the lower flange and having its inner wall adapted to slide freely between said axial shaft and the socket of said upper flange, the outer wall of said sleeve being adapted to abute said ring of said socket, a hydraulic cylinder and piston unit adapted to control the shaft movement in either direction and an exhaust valve at the bottom of said unit which becomes operative when the pressure of the hydraulic fluid contained therein exceeds that due to frictional contacts in order to preserve at each time of the flange movements the coincidence between the plane of symmetry of said bladder heels and the plane of symmetry of said tire.

2. Vulcanizing press as set forth in claim 1, which further comprises means for varying the relative spacing of said flanges, said means comprising essentially a hydraulic cylinder and piston unit consisting of an annular chamber formed between the socket rigid with said upper flange and the outer wall of the sleeve rigid with said lower flange.

3. Vulcanizing press as set forth in claim 1, comprising means for preserving said coincidence between the planes of symmetry of said tir and said bladder, said last-named means comprising a ball valve inserted in the exhaust circuit of the upper portion of said cylinder and piston unit and an electromagnet for controlling said valve.

4. Vulcanizing press as set forth in claim 1, wherein said socket rigid with said upper flange is tapped at its ends engaging a screw for adjusting the head of said drive shaft.

5. Vulcanizing press as set forth in claim 1, wherein said drive shaft is solid with an abutment plate adapted to be adjusted and to drive the sleeve rigid with said lower flange.