Tire mold and tire molding process
AssigneeSedepro
InventorAlain Soulalioux
Life of this patent
Estimating the term…
Abstract
The sector mold (11) is designed so that, during the molding phase, the molding elements (10, 10a, 10b, 10c) are all equidistant due to devices (13) which assure an elastic repulsion between each other. Some of the elements glide circumferentially with respect to their sector (11) in the final closing phase. In this way, pinching of the rubber between sectors and the appearance of molding burrs are avoided.
Claims19
A method of manufacturing a tire in a mold, comprising:
- assembling a raw rubber blank,
- introducing said rubber blank into a mold having a plurality of individual molding elements arranged in an annular ring, said plurality of elements defining, in closed molding position, a continuous annular molding surface on their radially inner faces, said continuous annular molding surface having a relief for the molding of a tread pattern on the radially outer surface of said tread, said continuous annular molding surface having a plurality of pattern units in the circumferential direction, each individual one of said elements having a circumferential length corresponding to one of said pattern units, each pattern unit defining only one pitch or two pitches, repulsion means being interposed between adjacent molding elements to separate them when they are arranged in an annular ring in a retracted position and providing an elastic repulsion in the circumferential direction between each of said elements at least during a final molding stroke and in the molding position,
- moving said elements to impart a contraction and enlargement to said ring of molding elements, including a relative circumferential movement between the elements coordinated with a movement of all of the elements along a direction toward and away from the axis of the mold between a retracted open and a closed molding position, said direction forming substantially the same angle with respect to the radial direction for each element.
A mold for a tire tread comprising at least 30 molding elements, defining, in molding position, a continuous annular ring for molding the radially outer surface of the tread, said elements being circumferentially adjacent in molding position, the radially inner face of each element molding a portion of said tread, the circumferential length of each individual molding element defining only one pitch or two pitches, repulsion means interposed between adjacent molding elements to separate them when they are arranged in an annular ring in a retracted position and providing an elastic repulsion in the circumferential direction between each of said elements at least during a final molding stroke and in the molding position.
A mold for a tire tread comprising a plurality of molding elements which in a retracted open position of the mold are spaced apart circumferentially in a ring, actuating means to impart a contraction and enlargement to the ring of molding elements, including a relative circumferential movement between the elements coordinated with a movement of all of the elements along a direction toward and away from the axis of the mold between a retracted open position and a closed molding position, said direction forming substantially the same angle with respect to the radial direction for each element, repulsion means interposed between adjacent molding elements to separate them when they are arranged in an annular ring in a retracted position and providing an elastic repulsion in the circumferential direction between each of said elements at least during a final molding stroke and in the molding position, said plurality of elements defining, in closed molding position, a continuous annular molding surface on their radially inner faces, said continuous annular molding surface having a relief for the molding of a tread pattern on the radially outer surface of said tread, said continuous annular molding surface having a plurality of pattern units in the circumferential direction, each individual one of said elements having a circumferential length corresponding to one of said pattern units, each pattern unit defining only one pitch or two pitches.
A mold for a tire tread comprising a plurality of molding elements arranged in an annular ring, the circumferential length of each individual molding element defining only one pitch or two pitches, actuating means to impart contraction and enlargement to said ring of molding elements, including a relative circumferential movement between the elements coordinated with a movement of all of the elements along a direction toward and away from the axis of the mold between a retracted open and a closed molding position, said direction forming substantially the same angle with respect to the radial direction for each element, said plurality of elements defining, in closed molding position, a continuous annular molding surface on their radially inner faces, repulsion means interposed between adjacent molding elements to separate them when they are arranged in an annular ring in a retracted position and providing an elastic repulsion in the circumferential direction between each of said elements at least during a final molding stroke and in the molding position, each of said elements having a circumferential length sufficiently small that the difference between the extreme circumferential components of the displacement observed at all points of the molding surface of each element is less than 0.04% of the molding perimeter at least during said final molding stroke.
A mold for tire tread comprising a plurality of molding elements arranged circumferentially in an annular array, resilient repulsion means interposed between each of the molding elements and the circumferentially adjacent molding elements to maintain them substantially equally spaced apart in a retracted position, actuating means to impart contraction and enlargement to said annular array of molding elements, including a relative circumferential movement between the elements coordinated with a movement of all of the elements along a direction toward and away from the axis of the mold between a retracted open and a closed molding position, said direction forming substantially the same angle with respect to the radial direction for each element, said plurality of elements defining, in a closed position, a continuous annular molding surface on their radially inner faces, said continuous annular molding surface having a relief for the molding of a tread pattern on the radially outer surface of a tread, said continuous annular molding surface having a plurality of pitches in the circumferential direction, each individual one of said elements having a circumferential length corresponding to one pitch.
Dependencies are inferred from the claim text.