Method and apparatus for building a closed torus tire

A method of manufacturing a closed torus pneumatic tire comprising:

• forming a generally cylindrical carcass structure including at least one cord reinforced ply;
• positioning a pair of inextensible bead cores coaxially about said cylindrical carcass structure and spaced in axial directions with respect to the carcass structure substantially in the position they will assume in the completed tire;
• radially expanding one axially outer end portion of said carcass structure by bladder means, drawing said one axially outer end portion without the aid of any internal restricting devices axially across the central portion of said carcass structure and forming a loop;
• providing a first external guide means adjacent said first loop to assure the precise axial positioning of said loop;
• releasing said one axially outer end portion;
• radially expanding the other axially outer end portion of said carcass structure by bladder means, drawing said other axially outer end portion without the aid of any internal restricting devices axially across the central portion of said carcass structure to form a second loop and a lapped portion with said first end portion;
• providing a second external guide means adjacent said second loop to assure the precise axial positioning of said loop;
• releasing said other axially outer end portion;
• adhering the end portions together at said lapped portion to form a closed torus chamber;
• positioning a preformed annular belt structure coaxially about said carcass structure;
• inflating said closed torus chamber into engagement with said preformed belt structure and firmly adhering said belt structure to said torus chamber;
• and
• providing tread rubber on the belt structure and vulcanizing the tire.

A method of building a closed torus pneumatic tire comprising:

• building a generally cylindrical cord reinforced structure;
• providing a pair of inextensible bead cores coaxially about said structure and adhered thereto in axially spaced apart positions substantially the same as they will assume in the completed tire;
• radially expanding one axially outer end portion of said carcass structure by bladder means causing said one axially outer end of said structure to rotate through an angle greater than 90.degree. from parallel to the axis of the structure by expanding said one axially outer end by exerting radially outwardly and axially inwardly directed forces on the radially inner surface thereof;
• gripping said one axially outer end and drawing said one axially outer end axially across said structure without the aid of any internal restraining devices forming a loop;
• radially expanding the other axially outer end portion of said carcass structure by bladder means causing said other axially outer end of said structure to rotate through an angle greater than 90.degree. from parallel to the axis of the structure by expanding said other axially outer end by exerting radially outwardly and axially inwardly directed forces on the radially inner surface thereof;
• gripping said other axially outer end and drawing said other axially outer end across said structure without the aid of any internal restraining devices forming a loop, and a lapped portion with said one axially outer end;
• adhering the axially outer ends together at said lapped portion to form a closed torus chamber;
• providing a tread structure;
• shaping the assembly to a tire form;
• and, vulcanizing the tire.