APPLICATION OF SEJOURNET

• Decision Date: 13 January 1961
• Docket Number: Patent Appeal No. 6622.
• Parties: Application of Jacques SEJOURNET.
• Court: U.S. Court of Customs and Patent Appeals (CCPA)

285 F.2d 823 (1961)

Application of Jacques SEJOURNET.

Patent Appeal No. 6622.

United States Court of Customs and Patent Appeals.

January 13, 1961.

Joseph R. Robinson, Jr., Pittsburgh, Pa. (Spencer B. Michael, Washington, D. C., Morton Burden, Jr., Webb, Mackey & Burden, Pittsburgh, Pa., of counsel), for appellant.

Clarence W. Moore, Washington, D. C. (Jack E. Armore, Washington, D. C., of counsel), for Commissioner of Patents.

Before WORLEY, Chief Judge, RICH, MARTIN, and SMITH, Judges, and Judge WILLIAM H. KIRKPATRICK.¹

SMITH, Judge.

Both the examiner and the Board of Appeals denied claims to appellant on a method of extruding a composite steel billet. This appeal was taken as to all of the rejected claims but has been withdrawn except as to claims 6 and 7. In his brief appellant presented claim 6 as an "example" claim and rewrote it in the form of claim 1, upon which it was dependent, substituting the word "steel" of claim 6 for the word "metal" in claim 1, as follows:

"6. A method of extrusion, which comprises placing in a container having a die located adjacent one end thereof through which the billet is extruded, a composite steel billet heated to extrusion temperature and composed transversely of at least two thicknesses of different steels, and extruding the billet so as to produce in the different cross sections of the extruded article substantially the same relative thicknesses of the different steels as in the corresponding cross sections of the original billet, by providing, prior to extrusion, a layer of glasslike lubricating material between the end of the billet and the die, said glass-like lubricating material melting at least partially but remaining viscous during extrusion."

Claim 7 is similar to claim 6 except that it specifies the inner part of the composite billet as being low carbon steel and the outer part as being stainless steel.

It will be seen that the method of extrusion covered by the claims specifically relates to the extrusion of a composite steel billet composed transversely of at least two thicknesses of different steels, each having different physical characteristics and properties. This billet is heated to extrusion temperatures and placed in the container of an extrusion press. An extrusion die is located adjacent one end of the container. A layer of glass-like lubricating material is placed between the billet and the inside walls of the container and between the end of the billet and the die. When the billet is extruded through the die, a product is said to be formed which has the different steels distributed in cross section in substantially the same relative thickness and proportion as they existed in a cross section of the composite starting billet. During extrusion, the glass-like lubricating material forms a viscous layer which acts as a lubricant between the billet and the die and between the billet and the inside walls of the container.

The problem in the art which appellant asserted was solved by his invention is summarized in his brief as follows:

"Prior to appellant\'s invention, extrusion as a method for fabrication of composite steel workpieces composed transversely of at least two thicknesses of different steels was seldom used due to extremely low yield of usable product. The low yield resulted from differential rates of metal flow which in turn caused substantial differences in distribution and proportion of the component steels in cross section between the workpiece and the product and from inability to predict the resulting distribution and proportion of the component steels in the product relative to those of the workpiece."

While the examiner relied upon twelve prior art references in finally rejecting the claims, the Board of Appeals affirmed the rejection upon the following three references:

                  Winston           2,023,498  December 10, 1935
                  Phillips          2,138,528  November 29, 1938
                  Sejournet et al.  2,538,917  January  23, 1951
                

The Winston patent discloses a method for producing composite metal articles of magnesium and magnesium alloys. As shown in the patent, a magnesium alloy core is placed within a sheath of another magnesium alloy different in composition from the core metal and the core and sheath are extruded through the die without the use of any lubricant. The patent points out that in order to produce a composite extruded product having a continuous layer of sheath metal of uniform thickness overlaid upon the core metal, the core and sheath "are so shaped that as they are extruded through a common die opening, a continuous layer of uniform thickness will be produced upon the core metal in the extruded billet."

The Phillips patent relates to a method for manufacturing metal valves for internal combustion engines, which valves have a core of soft steel and a sheath of stainless steel. The valve shown in the drawings is a poppet valve which normally is less than 6 inches in length and its method of manufacture involves extruding a previously heated billet composed of a core of soft steel and a sheath of stainless steel through the die to form the valve without using any lubricant in the extrusion operation.

The Sejournet patent relates to a method of extruding from a container through a die located at one end thereof a heated single metal workpiece whose melting point is above 900°C. Prior to extrusion, a layer of glass-like lubricating material, which becomes viscous during the extrusion...