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1. (WO1998051482) IMPROVED METHOD TO CURE ENDLESS TRACK BELTS AND APPARATUS THEREFOR
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CLAIMS
1. A method for curing endless track belts comprising:
a) providing a pair of upper and lower heated mold assemblies having an entrance end, an exit end, cooling water ports at each end, outer tread lug cavities in one half of a mold assembly, inner guide lug cavities in the other half of the mold assembly and a pair of fully supporting indexing wheels on opposing ends of the mold assemblies;
b) placing a green track belt carcass having a slab of tread lug compound built up on the outer surface thereof in between the mold halves and around the indexing wheels;
c) placing non-preformed slugs of inner guide lug compound in the inner guide lug cavities of the upper mold assembly and on the carcass opposite the guide lug cavities of the lower mold assembly;
d) turning on the water to all the cooling parts;
e) closing the mold halves at such a designated high pressure to form the tread lugs and guide lugs in a series of alternating bumps between high pressure and a much lower or no pressure to form the lugs;
f) applying a constant lower pressure to allow the lugs to expand into the cavities and the molds to separate until the first heat is complete;
g) opening the mold halves and indexing the belt a distance x which is less than the length of the molds until the lugs that were formed in the cavities next to the cold entrance end are aligned with the cavities at the exit end;
h) shutting off the cooling water at the exit end of the molds;
i) placing additional slugs of guide lug compound in the empty cavities of the upper mold and on the carcass opposite the empty cavities of the lower mold and repeating steps e, f and g for the second and subsequent heats prior to the final heat;
j) shutting off the cold water to the entrance ends of the molds;
k) placing additional slugs of guide lug compound in the empty cavities of the upper mold and on the carcass opposite the empty cavities of the lower mold and repeating steps e and f to form the final track belt; and
1) removing the track belt from the mold assemblies.
2. The method of claim 1 wherein the high pressure is between 1.4 MPa - 8.4 MPa.
3. The method of claim 1 wherein the high pressure is between 2.0 MPa - 3.3 MPa.
4. The method according to claim 1 wherein the lower pressure is between 0.35 MPa - 1.3 MPa.

5. The method according to claim 2 wherein the lower pressure is between 0.35 MPa - 1.3 MPa.
6. The method according to claim 3 wherein the lower pressure is between 0.5 MPa - 1.0 MPa.
7. The method for curing endless track belt comprising:
providing a pair of upper and lower heated mold assemblies having an entrance end, an exit end, cooling water ports at each end, outer tread lug cavities in one half of a mold assembly, inner guide lug cavities in the other half of the mold assembly and a pair of fully supporting indexing wheels on opposing ends of the mold assemblies;
a) placing a green track belt carcass having a slab of tread lug compound built-up on the outer surface and a slab of guide lug compound built-up on the inner surface thereof in between the mold halves and around the indexing wheels;
b) closing the mold halves at such a designated high pressure to form the tread lugs and guide lugs in a series of alternating bumps between high pressure and a much lower or no pressure to form the lugs;
c) applying a constant lower pressure to allow the lugs to expand into the cavities and the molds to separate until the first heat is complete;
d) the length of the molds until the lugs that were formed in the cavities next to the cold entrance end are aligned with the cavities at the exit end;
e) shutting off the cooling water at the exit end of the molds;
f) placing additional slugs of guide lug compound in the empty cavities of the upper mold and on the carcass opposite the empty cavities of the lower mold and repeating steps e, f and g for the second and subsequent heats prior to the final heat;
g) placing additional slugs of guide lug compound in the empty cavities of the upper mold and on the carcass opposite the empty cavities of the lower mold and repeating steps e and f to form the final track belt;
h) repeating steps d and e to form the final belt;
i) removing the track belt from the mold assemblies.
8. The method according to claim 7 wherein the high pressure is between 1.4 and MPa of 8. 9. The method of claim 7 wherein the high pressure is between 2.0 MPa - 3.3 MPa.
10. The method according to claim 7 wherein the lower pressure is between 0.35 MPa - 1.3 MPa.

11. The method according to claim 8 wherein the lower pressure is between 0.35 MPa - 1.3 MPa.
12. The method according to claim 9 wherein the lower pressure is between 0.5 MPa - 1.0 MPa.
13. The method of curing endless track belts comprising:
a) providing a pair of upper and lower heated mold assembhes having an entrance end, an exit end, cooling water ports at each end, outer tread lug cavities in one half of a mold assembly, inner guide lug cavities in the other half of the mold assembly and a pair of fully supporting indexing wheels on opposing ends of the mold assemblies;
b) placing a green track belt carcass in-between the mold halves and around the indexing wheels;
c) placing non-preformed slugs of inner lug compound in the inner guide lug cavities of the upper mold assembly and on the carcass opposite the guide lug cavities of the lower mold assembhes and slugs of tread lug compound in the tread lug cavities of the lower mold assembly on the carcass opposite the tread lug cavities of the upper mold assemblies; d) closing the mold halves at such a designated high pressure to form the tread lugs and guide lugs in a series of alternating bumps between high pressure and a much lower or no pressure to form the lugs;
e) applying a constant lower pressure to allow the lugs to expand into the cavities and the molds to separate until the first heat is complete;
f) opening the mold halves and indexing the belt a distance x which is less than the length of the molds until the lugs that were formed in the cavities next to the cold entrance end are aligned with the cavities at the exit end;
g) shutting off the cooling water at the exit end of the molds;
h) placing additional slugs of guide lug compound in the empty cavities of the upper mold and on the carcass opposite the empty cavities of the lower mold and repeating steps e, f and g for the second and subsequent heats prior to the final heat;
i) shutting off the cold water to the entrance ends of the molds;
j) placing additional slugs of guide lug compound in the empty cavities of the upper mold and on the carcass opposite the empty cavities of the lower mold and placing additional slugs of tread lug compound in the empty cavities of the lower mold and on the carcass opposite the empty cavities of the upper mold and repeating steps e and f to form the final track belt; and k) removing the track belt from the mold assembhes.
14. The method according to claim 13 wherein the high pressure is between 1.4 and MPa of 8.
15. The method of claim 13 wherein the high pressure is between 2.0 MPa - 3.3 MPa's. 16. The method according to claim 13 wherein the lower pressure is between 0.35 MPa - 1.3 MPa.
17. The method according to claim 14 wherein the lower pressure is between 0.35 MPa - 1.3 MPa.
18. The method according to claim 15 wherein the lower pressure is between 0.5 MPa - 1.0 MPa.
19. An apparatus for curing large endless rubber track belts comprising:
a) a pair of double platen mold assembhes having outer tread lug cavities, inner guide lug cavities, entrance ends, exit ends and cooling water ports at each end;
b) pressure cylinders to impart a cavity pressure of 1.4 to 8.4 MPa; and
c) fully supporting indexing wheels, wherein the indexing wheels provide support across the entire width of the belt with a force of 0.14 - 3.5 MPa during the curing cycle.

20. The apparatus according to claim 19 wherein the force applied by the fully supporting indexing wheels is 0.17 to 5.2 MPa.