Cold static gasket for complex geometrical sealing applications
View Patent ↗A gasket assembly ( 20 ) and method for forming the gasket assembly ( 20 ) for sealing two mating surfaces ( 46,48 ) over a complex geometrical contact region. The gasket assembly ( 20 ) is formed by a hollow silicone rubber tube ( 22 ) having a naturally straight configuration but easily bent into complex configurations without kinking. The tube ( 22 ) is filled with a curable liquid rubber compound ( 30 ) and then the ends ( 24,26 ) of the tube ( 22 ) are joined in end-to-end fashion to form a continuous loop. The joined ends ( 24,26 ) of the tube ( 22 ) can be reinforced with a connector ( 34,134 ) and then locally cured on a preliminary operation so that the liquid rubber compound ( 30 ) does not escape. The tube ( 22 ) is then laid up in a mold ( 40 ) having a complex geometrical feature ( 42 ) which replicates the complex geometrical contact region of the two mating surfaces ( 46,48 ) to be subsequently sealed. With the tube ( 22 ) held stationary in the mold form ( 40 ), the entrapped liquid rubber compound ( 30 ) is cured using a heat source ( 44 ) or other suitable curing accelerant. Once fully cured, the core of rubber compound ( 30 ′) takes a set in the complex geometrical form, and resists straightening of the tube ( 22 ) so as to hold the gasket assembly ( 20 ) in the complex geometrical shape required to later seal the mating surfaces ( 46,48 ). The tube ( 22 ) and core of cured rubber compound ( 30 ′) may be selected of materials which possess different durometers.
1. A method for forming a shaped gasket of the type for sealing two mating surfaces over a complex geometrical contact region, said method comprising the steps of:
providing a length of hollow, resilient tube extending continuously between first and second opposing and disjointed ends while the other end remains open and unobstructed;
filling the entire length of the tube with an uncured liquid rubber compound through one of the first and second ends;
preventing escape of the uncured liquid rubber compound from the first and second ends of the tube by joining the ends of the tube together with a loose-piece connector bridging the first and second ends;
providing a mold form having a complex geometrical feature replicating the complex geometrical contact region of the two mating surfaces to be sealed;
laying up the tube filled with uncured liquid rubber compound in the mold form;
curing the liquid rubber compound while holding the tube stationary relative to the mold form;
removing the tube filled with cured rubber compound from the mold form such that the tube retains the complex geometrical shape of the mold form feature;
compressing the tube filled with cured rubber compound between the two mating surfaces to perfect a seal therebetween; and
wherein said step of curing the liquid rubber compound includes hardening the liquid rubber to a final specified durometer, and further including the step of forming the connector from a resilient rubber material having a durometer measure generally equal to the specified durometer of the cured liquid rubber compound.
2. The method of claim 1 wherein said step of joining the first and second ends includes curing the liquid rubber compound immediately adjacent the first and second ends prior to said step of laying up the tube in the mold form.
3. The method of claim 1 wherein said step of providing a length of tube includes forming the tube from a rubber material having a specified durometer, and said step of curing the liquid rubber compound includes hardening the liquid rubber to a final specified durometer different than the specified durometer of the tube.
4. The method of claim 3 wherein said step of hardening the liquid rubber compound to a final durometer includes achieving a durometer number lower than the specified durometer of the tube.
5. The method of claim 1 wherein said step of providing a length of tube includes forming the tube from a rubber material having a generally annular cross-section.
6. The method of claim 5 wherein said step of forming the tube includes fabricating the tube from a silicone rubber material.
7. The method of claim 1 wherein said step of providing a length of tube includes unwinding the tube from a spool.
8. The method of claim 1 wherein said step of curing the liquid rubber includes heating.