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4930418 : Method for sealing optical windows in explosive initiators
INVENTORS: Folsom; Mark, Hollister, CA
ASSIGNEES: Whittaker Ordnance, Inc., Hollister, CA
ISSUED: June 5 , 1990 FILED: June 23, 1989
SERIAL NUMBER: 370495 FEE STATUS:  
INTL. CLASS (Ed. 5): F42C 19/00; C03C 27/02; C03C 29/00;
U.S. CLASS: 102-201; 065-043; 065-154;
FIELD OF SEARCH: 102-201 ; 065-36,42,43,59.1,59.3,59.34,59.4,152,154 ;
AGENTS: Nist; Donald E.;

ABSTRACT:   The method seals optical windows in explosive initiators so that the resulting seal remains undamaged by exposure to about - 320°-840° F. and pressures up to 26000 psi. The method includes disposing a solid body optical window of quartz or silica glass or the like in a passageway in a wall of an explosive initiator body of metal, ceramic or the like. The optical window is dimensioned relative to the passageway so that an annular space is provided between the outer periphery of the optical window and the passageway wall. This annular space is filled with solder glass, in powdered or solid body or slurry form. Preferably, the solder glass is a ring which closely fits around the optical window. The resulting sub-assembly preferably abuts a shelf in the passageway formed between two contiguous portions of the passageway with different diameters, the sub-assembly being in the larger portion. The assembly of solder glass, optical window and initiator body is then heated to above the melting point of the solder glass, e.g. about 450° C. and held at this temperature until the solder glass melts and fuses to the optical body and passageway wall, sealing the optical body in place. The assembly is then cooled to ambient temperature.

U.S. REFERENCES:

Patent No. Patentee Issue Date
3528372 * Lewis et al. Sep. 1 , 1970
3672858 Berg June 1 , 1972
3362329 * Epstein Jan. 1 , 1968
3296795 * Nielsen et al. Jan. 1 , 1967
3367696 * Langley Feb. 1 , 1968
3069876 * Certa et al. Dec. 1 , 1962
4343242 Welk Aug. 1 , 1982
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10 CLAIMS: First Claim Shown (Show all claims)

What is claimed is:

  • 1. An improved method for sealing optical windows in explosive initiators, said method comprising:
    • (a) disposing a solid body optical window in a passageway in a wall of an explosive initiator body to provide an annular space between said passageway wall and the outer periphery of said optical window body;
    • (b) filling said annular space with solder glass to form an assembly;
    • (c) heating said assembly to above the melting point of said solder glass for a time sufficient to melt said solder glass and fuse it to said optical window and said passageway wall so as to seal said optical window body in said passageway against leaks;
    • (d) thereafter cooling said assembly to ambient temperature sufficiently slowly so as to prevent cracking of said solder glass and window.

RELATED U.S. APPLICATIONS: none
FOREIGN REFERENCES: none
OTHER REFERENCES: none
PRIMARY/ASSISTANT EXAMINERS: Jordan; Charles T.;