James J Tobin

US Patent:

59273739, Jul 27, 1999

Filed:

Feb 12, 1997

Appl. No.:

8/799747

Inventors:

James R. Tobin - Cincinnati OH

Assignee:

The Procter & Gamble Company - Cincinnati OH

International Classification:

B22C 904

US Classification:

164 36

Abstract:

A method of constructing a fully dense metal part or a metal mold half for matin with another mold half to form a mold for casting multiple parts. Steps include placing a pattern having critical pattern surfaces in a flask having an open end. The critical pattern surfaces face upward. Other steps involve covering the critical pattern surfaces with a concentrated heat reversible gel solution added to the flask, and cooling the gel solution to form an elastic solid gel mold. Further steps include removing the flask and the pattern from the elastic gel mold, and casting a ceramic mold around the solid gel mold. In other steps the gel mold is liquified for removal from the ceramic mold and the ceramic mold is inverted so that its critical ceramic surfaces face upward. Still other steps involve covering the critical ceramic surfaces with a powder, and placing a quantity of an infiltration material over the powder, and placing the ceramic mold, the powder, and the infiltration material in a furnace at a temperature sufficient to melt the infiltration material without melting and sintering the powder. The quantity of the infiltration material is sufficient to fill voids between the particles, thereby generating a fully dense mold half.

US Patent:

55073360, Apr 16, 1996

Filed:

Jan 17, 1995

Appl. No.:

8/373137

Inventors:

James R. Tobin - Cincinnati OH

Assignee:

The Procter & Gamble Company - Cincinnati OH

International Classification:

B22C 904
B22D 1914

US Classification:

164 34

Abstract:

A method of constructing a fully dense metal part or a metal mold half for mating with another mold half to form a mold for casting multiple parts. Steps include placing a pattern in a tubular mold base, casting a ceramic member onto critical surfaces of the pattern, removing the pattern from the mold base, covering the critical surfaces transferred to the ceramic member with a powdered metal having a melting temperature greater than that of an infiltration metal, placing a quantity of an infiltration metal over the powdered metal, placing the tubular mold base in a furnace at a temperature sufficient to melt the infiltration metal without melting the powdered metal, and removing the ceramic member from the first open end of the tubular mold base to expose the critical surfaces. The quantity of the infiltration metal is sufficient to fill voids between the particles of the powdered metal when the infiltration metal is melted, thereby generating a fully dense metal part. The metal part has the critical surfaces transferred from the ceramic member when the infiltration metal solidifies.

US Patent:

59067810, May 25, 1999

Filed:

Dec 11, 1996

Appl. No.:

8/764675

Inventors:

James Robert Tobin - Cincinnati OH

Assignee:

The Procter & Gamble Company - Cincinnati OH

International Classification:

B29C 3340

US Classification:

264220

Abstract:

A method for forming a ceramic mold comprises the step of placing a pattern having critical pattern surfaces in a flask having an open end. The critical pattern surfaces face upward toward the open end. Successive steps include adding a concentrated heat reversible gel solution to the flask to cover the critical pattern surfaces, and cooling the gel solution to form an elastic solid gel mold. The gel mold has critical gel mold surfaces inverse to the critical pattern surfaces. Further steps include removing the pattern from the elastic gel mold, casting a ceramic mold around the gel mold, and liquifying the gel mold to remove it from the ceramic mold. The ceramic mold has critical ceramic surfaces inverse to the critical gel mold surfaces, thereby accurately replicating the critical pattern surfaces.