The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 15, 2000
Filed:
May. 09, 1997
Matthew T Gardner, Troy, NY (US);
David A Larsen, Clifton Park, NY (US);
Blasch Precision Ceramics, Inc., Albany, NY (US);
Abstract
A riser tube for transfer of molten metal therethrough, including a porous ceramic substrate having a hollow cylindrical structure and ceramic impregnant material penetrating into pores of the substrate and plugging at least a portion of the surface pores thereof, to improve gas impermeability of the substrate. According to the present invention, the porous ceramic substrate is immersed in impregnation media containing ceramic particles, the impregnation media is subjected to an elevated pressure such that the media penetrates the pores of the substrate, and the impregnated substrate is then fired, whereby the ceramic particles form a ceramic impregnant material that plugs at least a portion of the surface pores of the substrate.