US 4,305,446 AGranted

Cast tire and method of manufacture

AssigneeThe Goodyear Tire & Rubber Company

InventorsJack E. Brown, Jr., Brian M. Logan, Michael J. Trinko

Life of this patent

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Abstract

An annular hollow tire with an inner surface having a generally positive radius of curvature and at least one circumferentially extending rib portion on the inner surface with a negative radius of curvature located at an area of the tire subject to high stresses to mitigate the stress concentrations in that area of the tire. The method of making the tire includes the steps of providing a tire mold with a core having a selected circumferentially extending portion on the outer surface with a negative radius of curvature for forming the rib portion, filling the space between the core and mold surface with an elastomeric precursor, heating to set the precursor and form the tire and removing the tire from the mold and the core from the tire.

Claims15

Dependent claims

A cast pneumatic tire comprising a tread portion, a pair of circumferentially extending sidewalls with outer peripheral portions connected to said tread portion and spaced apart inner peripheral portions which are connected to bead portions respectively each containing an inextensible bead ring, said tread portion further provided with a circumferentially extending reinforcing belt structure having a pair of circumferential edges spaced from either side of said midcircumferential centerplane of the tire a first distance, each of said sidewalls consisting of an elastomeric material, an outer surface, an inner surface extending between said inner peripheral portions, a first pair of circumferentially extending rib portions, one located near each of said circumferential edges of said reinforcing belt structure on the inner surface and the centroid of the cross-sectional area of each of said rib portions being spaced from the midcircumferential plane a second distance measured axially of said tire from the midcircumferential centerplane of said tire and the difference between said first distance and second distance being equal to or less than one-half the width of either of said first rib portions, a circumferentially extending unfolded reinforcing strip with parallel edges is located in each of the bead portions of said tire, a second pair of rib portions, one being located adjacent said reinforcing strip on the inner surface and having a width greater than the width of said strip so that each of said second rib portions overlap the edges of said reinforcing strip.

A method of making a cast pneumatic tire having a tread portion, a pair of circumferentially extending sidewalls with outer peripheral portions connected to said tread portion and spaced apart inner peripheral portions, said sidewalls consisting of an elastomeric material, said tread portion being provided with a circumferentially extending reinforcing belt structure having a pair of circumferential edges spaced from either side of said midcircumferential centerplane of the tire a first distance, said inner peripheral portion each being provided with a circumferentially ending reinforcing strip with parallel edges, comprising the steps of:

providing an annular rigid tire mold having a mold cavity with an inner molding surface for forming the outer surface of said tire;
providing an annular rigid core inside said mold having an outer molding surface spaced from said inner molding surface;
providing said outer molding surface with a general positive radius of curvature for forming the inner surface of the tire;
providing a pair of circumferentially extending portions on said outer surface of said core with a negative radius of curvature for forming areas of increase thickness of said tire in each of said sidewalls which are subjected to high stresses, casting said tire by filling the space between said outer and inner molding surface with an elastomeric precursor, setting the precursor to form in each of said sidewalls of said tire with a first circumferentially extending rib and a second circumferentially extending rib, said first circumferentially extending rib being located near said circumferential edge of said reinforcing belt structure and the centroid of the cross-sectional area of said rib being spaced from the midcircumferential plane a second distance measured axially of said tire from the midcircumferential centerplane of said tire and a difference between said first distance and second distance being equal to or less than one-half the width of said first rib portion, said second circumferential rib portion located adjacent said reinforcing strip and having a width greater than the width of said reinforcing strip so that said second rib portion overlaps the edges of said reinforcing strip;
removing said tire from said mold cavity.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/216,697Filed 15 Dec 1980 · continuation
Priority: 30 Nov 1977
Granted: 15 Dec 1981
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

B29D 30/0661
Vulcanising tyres; Vulcanising presses for tyres: rigid cores therefor, e.g. annular or substantially toroidal cores
B29D 30/06
Producing pneumatic or solid tyres or parts thereof: pneumatic tyres or parts thereof
B60C 3/04
Tyres characterised by the transverse section: characterised by the relative dimensions of the section, e.g. low profile
B60C 13/00
Tyre sidewalls