초록 ▼

The present invention provides novel apparatus and a novel method for manufacturing an endless rubber track for large vehicles such as tractors or earth-moving machines. A plurality of sprocket-engaging core bar inserts are disposed in the inner portion or inner diameter of the endless rubber track

The present invention provides novel apparatus and a novel method for manufacturing an endless rubber track for large vehicles such as tractors or earth-moving machines. A plurality of sprocket-engaging core bar inserts are disposed in the inner portion or inner diameter of the endless rubber track to engage the power drive mechanism of the vehicle. Rubber tread is disposed on the outer portion or external diameter of the rubber track. Although the rubber track is made in segments, it is completely vulcanized, and does not have discontinuous, unvulcanized regions between vulcanized segments. Rubber track is formed using at least two different mold assemblies. In the first mold assembly, the interior and exterior portions of the rubber track are molded onto a green belt to form a first segment, and a central portion of the segment is vulcanized. In the second mold assembly, the interior and exterior portions of the rubber track are molded onto an adjacent section of the green belt to form a second belt segment, and the second segment along with the adjacent unvulcanized first segment is vulcanized.

대표청구항 ▼

A method for producing an endless rubber track, comprising the steps of: a.) providing a first mold assembly which includes an inner mold half having a cavity patterned in the form of an interior of the rubber track, an outer mold half which mates with the inner mold half having a cavity patterned i

A method for producing an endless rubber track, comprising the steps of: a.) providing a first mold assembly which includes an inner mold half having a cavity patterned in the form of an interior of the rubber track, an outer mold half which mates with the inner mold half having a cavity patterned in the form of an exterior portion of the rubber track, a removable subplate positioned between the inner and outer mold halves, and positioning means for positioning the inner mold half, the outer mold half and the removable subplate in relationship to one another; b.) placing a first quantity of green rubber adjacent the inner mold half of the first mold assembly, the quantity of rubber being sufficient to fill the inner mold half cavity; c.) positioning a first side of the subplate of the first mold assembly adjacent to the first quantity of green rubber utilizing positioning means; d.) placing a second quantity of green rubber adjacent a second side of the subplate of the first mold assembly, the quantity of rubber being sufficient to fill the outer mold half cavity; e.) positioning the outer mold half of the first mold assembly over the second quantity of green rubber utilizing positioning means; f.) heating the first mold assembly to an elevated temperature sufficient to soften the first and second-quantity of green rubber while applying sufficient pressure to flow the softened rubber into the mold cavities without vulcanizing the rubber; next g.) separating the inner and outer mold halves and removing the subplate while the rubber remains in the inner and outer mold halves of the first mold assembly; h.) placing a portion of a green belt in the shape of an endless loop between the inner and outer mold halves; i.) closing the rubber-containing mold halves of the first mold assembly against the green belt portion so that it is sandwiched between the inner and outer mold halves to form an assembly having a central portion of preselected length P and two end portions each having a preselected length L; j.) applying heat to the first mold assembly to raise the temperature of the green rubber in the central portion of the assembly to a temperature above the vulcanizing temperature of the rubber, while simultaneously maintaining the end portions of the assembly at a temperature below the vulcanization temperature of the rubber, and applying pressure to the assembly to form a rubber track segment with a length P+2L, the rubber track segment having a vulcanized rubber track segment central portion of length P and green rubber track segment end portions each having preselected length L; k.) removing the mold halves of the first mold assembly from the formed rubber track segment; l.) repeating steps b-k on the green belt at a distance of Q from the rubber track segment; m.) providing a second mold assembly which includes an inner mold half having a cavity patterned in the form of an interior of the rubber track, an outer mold half which mates with the inner mold half having a cavity patterned in the form of an exterior portion of the rubber track, a removable subplate having two end portions and a central portion of preselected length Q in the form of a substantially flat plate extending between the end portions, each of the end portions being greater than preselected length L, and further having an inner portion patterned in the form of the interior portion of the rubber track so as to engage a portion of the inner mold half cavity, an outer portion patterned in the form of the exterior portion of the rubber track so as to engage a portion of the outer mold half cavity, the subplate positioned between the inner and outer mold halves, and positioning means for positioning the inner mold half, the outer mold half and the removable subplate in relationship to one another; n.) placing a third quantity of green rubber adjacent the inner mold half of the second mold assembly, the quantity of rubber being sufficient to fill the inner mold half cavity opposite the central portion of the subplate for the length Q; o.) positioning a first side of the subplate of the second mold assembly adjacent to the third quantity of green rubber utilizing positioning means; p.) placing a fourth quantity of green rubber adjacent a second side of the subplate of the second mold assembly, the quantity of rubber being sufficient to fill the outer mold half cavity opposite the central portion of the subplate for the length Q; q.) positioning the outer mold half of the second mold assembly over the fourth quantity of green rubber utilizing positioning means; r.) heating the second mold assembly to an elevated temperature sufficient to soften the third and fourth quantities of green rubber while applying sufficient pressure to flow the softened rubber into the central portion of mold cavities having the length Q without vulcanizing the rubber and preventing rubber from flowing into the end portions of the cavities; next s.) separating the inner and outer mold halves and removing the subplate while the rubber remains in the inner and outer mold halves of the second mold assembly; t.) placing the portion of the green belt having length Q, the green belt located between formed rubber track segments having vulcanized central portions of length P and green rubber end portions of preselected length L, the green belt being located between the central portions of the mold half cavities of the second mold assembly, the cavities being filled with green rubber; u.) closing the mold halves of the second mold assembly against the green belt portion so that the green belt portion is sandwiched between the central portions of the inner and outer mold halves, and the green rubber track segment end portions of preselected length L formed by the first mold assembly are captured in the end portions of vulcanized rubber track segment central portion P formed by the first mold assembly, the end portion cavities of the second mold assembly having a length greater than preselected length L; v.) applying heat to raise the temperature of the green rubber in the second mold assembly to a temperature above the vulcanizing temperature of the rubber, while applying pressure to the assembly to form a vulcanized rubber track segment; w.) removing the mold halves of the second mold assembly from the vulcanized track segment; x.) repeating steps m-w until an endless vulcanized rubber track is produced. Apparatus for producing an endless rubber track comprising: a first mold assembly for forming partially vulcanized rubber track segments, the first mold assembly including an inner mold half having a first end and a second end free of a cavity pattern and a center portion including a cavity patterned in the form of an interior of the rubber track, an outer mold half having a first end and a second end free of a cavity pattern and a center portion including a cavity patterned in the form of an exterior of the rubber track, the outer mold half mating with the inner mold half, a removable subplate positioned between the inner and outer mold halves, positioning means for positioning the inner mold half, the outer mold half and the removable subplate in relationship to one another, and cooling means to cool the mold halves for a preselected length L from the mold half ends; heating means for heating the center portion of the first mold assembly, and; insulation positioned at the preselected length L from the mold half ends; a second mold assembly for fully vulcanizing rubber track segments, the second mold assembly including an inner mold half having a first end and a second end and including a cavity patterned in the form of an interior of the rubber track, an outer mold half having a first end and a second end and including a cavity patterned in the form of an exterior of the rubber track, the outer mold half mating with the inner mold half, a removable subplate having two end portions and a central portion extending between the end portions, each of the end portions having a length greater than the preselected length L, and further having an inner portion patterned in the form of the interior portion of the rubber track so as to engage a portion of the inner mold half cavity, an outer portion patterned in the form of the exterior portion of the rubber track so as to engage a portion of the outer mold half cavity, and a central portion in the form of a substantially flat plate extending between the end portions, the subplate positioned between the inner and outer mold halves, and positioning means for positioning the inner mold half, the outer mold half and the removable subplate in relationship to one another; and heating means for heating the second mold assembly.