The invention relates to rubber compositions that are provided with polyorganosiloxanes as plasticizers. The rubber compositions can be vulcanized by means of a cross-linking resin and they are particularly suitable for use as curing bladders in the production of tires. The invention further relates to the use of polyorganosiloxanes as corresponding plasticizers.

The invention relates to a method for curing a tire, during which there is deployed, against the interior surface of said tire, a curing membrane of which the contact surface is provided with a drainage structure which comprises air-discharge channels and which is subdivided into a first drainage region which will be pressed intimately against the crown region of the tire, a second drainage region which will be pressed intimately against the sidewall region, and a third drainage region which will be pressed intimately against the bead region, and which is such that the mean depth of the channels of the third drainage region is strictly greater than the mean depth of the channels of the second drainage region, which is itself strictly greater than the mean depth of the channels of the first drainage region.

Provided are a vulcanization device for a pneumatic tire and a method for vulcanizing a pneumatic tire. A pressurizing medium having a relatively low pressure is supplied through a pressurizing medium low-pressurization/supply line into a vulcanization bladder having a tube-like shape inserted into a green tire in a vulcanization mold to inflate the vulcanization bladder. Thereafter, a heating medium is supplied through a heating medium supply line into the vulcanization bladder (2). Then, a pressurizing medium having a relatively high pressure is supplied through a pressurizing medium supply line into the vulcanization bladder to increase internal pressure of the vulcanization bladder while the media in the vulcanization bladder are circulated through a circulation line extending outside the vulcanization bladder, thereby vulcanizing the green tire.

Disclosed is an elastomeric bladder tool and related systems and methods. In one embodiment, the elastomeric bladder tool comprises an elastomeric inner layer substantially defining an inner cavity of the elastomeric bladder tool, an elastomeric outer layer substantially defining an outer surface of the elastomeric bladder tool, and a permeable middle layer positioned between the elastomeric inner layer and the elastomeric outer layer. The permeable middle layer has greater permeability than both the elastomeric outer layer and the elastomeric inner layer to allow for evacuating of gases that have entered the permeable middle layer.

Provided is a pneumatic tire vulcanizing method which includes the steps of setting a green tire in a mold, inserting a bladder inside the green tire, and expanding the bladder to press the bladder to an outer side in the tire radial direction and perform vulcanization molding. The bladder is expanded with a rigidity reinforcement ring interposed between an inner circumferential surface of a region of the green tire corresponding to a tread portion and an outer circumferential surface of a region of the bladder corresponding to the tread portion.

A method of manufacturing a pneumatic tire includes placing a bladder device including a vulcanization bladder at a holding position outside a mold; inserting the vulcanization bladder in a green tire with a tire axis central position of the green tire and a shaft central position of the vulcanization bladder aligned; aligning a central position in a tire width direction of the green tire and a central position in a shaft direction of the vulcanization bladder; supporting the green tire with the vulcanization bladder by inflating the vulcanization bladder to a predetermined green tire supportable internal pressure; bringing the vulcanization bladder in contact with an inner surface of the green tire; transporting the green tire together with the bladder device to the vulcanization device; setting the green tire with the bladder device in the mold; inflating the vulcanization bladder to a predetermined vulcanization internal pressure; and vulcanizing the green tire.

A tire holding device of a tire mounting machine grasps the bead section of a green tire by chucking paddles and places the green tire around an upright cylindrical vulcanization bladder. A bladder device of the tire mounting machine expands the vulcanization bladder to press same against the inner surface of the green tire, and sets the green tire in a vulcanization-mold. On a lower portion of each chucking paddle, guide extensions are formed to extend in the two circumferential directions. Between adjacent chucking paddles, the guide extensions extend toward each other and constantly overlap each other to prevent the expanding vulcanization bladder from contacting the radially inner surface of the bead section and from stripping the non-vulcanized rubber of the green tire.

A tire manufacturing method includes: a frame forming process of forming a tire frame member using a resin material; an unvulcanized rubber placement process of disposing unvulcanized rubber so as to span from an outer face of a side portion across to an inner face of a bead portion of the tire frame member; and a vulcanization process of vulcanization molding the unvulcanized rubber using a vulcanization machine in which a recessed portion is formed in an inner side mold face among mold faces for vulcanization molding the unvulcanized rubber, the inner side mold face being for vulcanization molding part of the unvulcanized rubber disposed on the inner face of the bead portion.

Equipment for molding and curing a green tire includes a curing mold including a first bead molding ring including a first surface for contacting a radially inner and axially inner surface portion of an annular fixing structure of the green tyre and a first sidewall plate including a second surface for contacting a radially inner and axially outer surface portion of the annular fixing structure. The first bead molding ring is radially extendable from a contracted operating position to an expanded operating position so as to delimit a portion of the annular fixing structure between the first sidewall plate and the first bead molding ring, and the first bead molding ring is translatable towards the first sidewall plate for generating a first squeezing pressure on the annular fixing structure. The equipment further includes an inflatable bladder associated for operation with the curing mold.

An example of a piping structure of a tire vulcanizer to which the present invention is applied has a central mechanism 1 of the tire vulcanizer as illustrated in FIG. 1. The central mechanism 1 has a bug head 2, a hydraulic cylinder 3, and exhaust circulation path pipes 4. In addition, the central mechanism 1 has a bladder (not illustrated) which may be expanded and contracted as a vulcanizing medium is supplied into the bladder. One end of the exhaust circulation path pipe 4 is connected to an interior of the bladder, and the two exhaust circulation path pipes 4 are connected to each other through a bypass pipe 5. The other end of the exhaust circulation path pipe 4 is connected to an exterior of the central mechanism 1.