The B. F. Goodrich Company

The Uniroyal Goodrich Tire Company

Donald R Bartley

James Sidles

Jerome J Blayne

Rene L Rockarts

Robert F Jones

Stephen C Sabo

John P Czarnecki

Shamim Ahmad

James M Haase

A tire molding system includes a mold having a surface defining a cavity for receiving and shaping an uncured tire. The uncured tire is pressed against the surface defining the cavity. Fluid is evacuated from between the uncured tire and the surface defining the cavity. A recess extends from the cavity for forming a marking on the sidewall of the tire. A passage fluidly communicates the recess with the exterior of the mold. The passage includes a first end portion adjacent the recess and a second end portion adjacent the exterior of the mold. The second end portion extends for a distance less than one-half of the total length of the passage. A restrictor is located entirely within the second end portion of the passage for restricting fluid flow through the passage during the evacuation of fluid and before the recess is sealed off from the cavity by the uncured tire when the uncured tire is pressed against the surface defining the cavity.

Restrictor for tire mold vent passage and method of use

In a tire mold having a pair of mold parts separable about cooperating surfaces of the respective mold parts which define a parting line region, each of the mold parts includes a surface defining at least a portion of a cavity for shaping a tire. The tire mold further includes a plurality of pockets for defining a respective plurality of circumferentially arranged tread elements in the tire. The improvement comprises a vacuum source in fluid communication with the cavity of the tire mold for evacuating fluid from the cavity in the tire mold through a space located between the surfaces of the mold parts which define the parting line region. A vent fluidly connects a pair of adjacent pockets. A passage associated with one of the mold parts provides fluid communication between the vacuum source and one of the pair of adjacent pockets connected by the vent.

Vented tire mold and method for vacuum molding

A split tire mold having a tread ring in which provision is made for venting air circumferentially across the inner surface of the tread ring so that the air escapes from the parting line of the mold halves, dispenses with widely used, conventional, radially protruding vent stubs. The air is vented through 'butterfly-shaped' or 'double-wedge-shaped' arch-vents which provide passage for trapped air above each tread block of the tread as it is moved against the inner surface of the tread ring. The shape of the arch-vent passages and the angulation of the wedges is critical to the effectiveness of the arch-vent which forms an arch-vent bridge of cured rubber in a cured tire. The configuration of the bridge allows as cured tire to be easily removed from the mold cavity without leaving a broken-off piece of the rubber bridge to plug the arch-vents. This arch-vent design leaves unobtrusive flat-sided, narrow wedge-shaped pieces of rubber as the arch-vent stubs, tapered in two directions. The arch-vent stubs, when viewed in the radial direction towards the center of the tire, are so unobtrusive as to be cosmetically acceptable in a finished tire. The upper surface of the arch-vent is close to the inner surface of the tread ring and essentially horizontal, while the lower surface of each arch-vent is inclined at an angle in the range from 30.degree.-50.degree. to the horizontal plane, but in opposite directions. An angle in this range provides surprising strength in the base area of the arch-vent stub so that, upon stripping the tire from the mold, the arch-vent bridge of cured rubber breaks cleanly and reliably at the narrowest and weakest point in the bridge.

Tire and method of producing same

A split tire mold having a tread ring having arch-vents for venting air circumferentially across the inner surface of the tread ring so that air escapes from the parting line of the mold halves. The 'dougle-wedge-shaped' arch-vents provide passage for trapped air above each tread block of the tread as it is moved against the inner surface of the tread ring. The shape of the arch-vent passages and the angulation of the wedges is critical to the effectiveness of the arch-vent which forms an arch-vent bridge of cured rubber in a cured tire. The configuration of the bridge allows a cured tire to be easily removed from the mold cavity without leaving a broken-off piece of the rubber bridge to plug the arch-vents. This arch-vent design leaves flat-sided, narrow wedge-shaped pieces of rubber as the arch-vent stubs, tapered in two directions. The arch-vent stubs, viewed in the radial direction are so unobtrusive as to be cosmetically acceptable in a finished tire. The upper surface of the arch-vent is close to the inner surface of the tread ring and essentially horizontal, while the lower surface of each arch-vent is inclined at an angle in the range from 30.degree. -50.degree. to the horizontal plane, but in opposite directions. An angle in this range provides strength in the base area of the arch-vent stub so that, upon stripping the tire from the mold, the arch-vent bridge of cured rubber breaks cleanly and reliably at the narrowest and weakest point in the bridge.

Plug-resistant arch-vents for a tire mold

A method and apparatus whereby tire mold is closed to within approximately one inch of full closure with a green tire in place therein for molding, and the mold is then evacuated employing a vacuum conduit prior to full mold closure whereby air within the mold cavity is evacuated and the necessity for vent holes in the mold is eliminated. A mold for practice in the invention is free of vent holes in the thread, sidewall, and bead portions of the mold and includes, along the parting line, at least one vacuum conduit whereby the mold cavity may be evacuated to not more than 16932 Pa within not more than about 60 seconds employing a source of vacuum. Seals are provided radially outward of the vacuum conduit along the parting line, and, where necessary, adjacent any moveable bead ring associated with the tire mold. Seals are preferably of a type wherein a differential between pressures experienced by one seal surface and obverse seal surface cause a more effective sealing arrangement. Tires emerging from the mold in accordance with the processes of this invention are free of rubber projections associated with cured rubber entering into vent holes associated with ordinary tire molds.

Method for ventless tire molding

Apparatus for ventless tire molding

A tire mold having air venting passages or holes is provided with plastic inserts or plugs for the vent holes along the cavity side of the mold. The inserts are composed of a plastic material having a heat distortion temperature of no less than 275.degree. F. at 66 psi in accordance with ASTM D648 and a coefficient of thermal expansion less than 8.times.10.sup.-5 in/in/.degree.C.

Tire mold with air vent inserts

A vehicular pneumatic tire which, except for bead cores, is composed solely of an elastomeric blend strengthened by molecular orientation. The blend is a monoolefin copolymer rubber with a polyolefin and sufficient curing agents to effect vulcanization when the blend is subjected to heat and pressure. The process for making the tire comprises preforming an annulus of the elastomeric blend with bead cores adjacent the edges, the diameter of the preform being essentially that of the bead diameter of the completed tire and the axial distance between the beads less than the transverse arcuate dimension of the completed tire. The preform is cured and while still hot following curing, is stretched and shaped to final size and the generally toroidal form characteristic of conventional pneumatic tires with resulting biaxial molecular orientation, which orientation is retained in the tire by cooling it below the melting point of the polyolefin before removing the tire from the mold.

Vehicle tire

A pneumatic tire is adapted for combination with an internally situated device, such as an emergency support member. The tire has at least one specially constructed bead portion which includes a conventional bead core or member and an additional bead member spaced axially inwardly therefrom. In the space between the two bead members is formed an anchoring channel contoured to tightly receive an anchoring means provided on the device to be situated internally of the tire.

Growing community of inventors

Cuyahoga Falls, OH, United States of America

Donald R Bartley