Application of Wilbur E. Shearman

BALDWIN, Judge.

Shearman appeals from the decision of the Patent Office Board of Appeals which affirmed the rejection of claims 1-3, 6, 7, 12 and 13 of his application¹ as unpatentable over the prior art.

THE INVENTION

Appellant’s invention is a ceramic sheath for enclosing the sensing tip of a thermocouple for use in measuring the temperature of molten metal in a melting furnace.

Figure 1 of the drawing is illustrative:

This figure shows an outer sheath 21of ceramic refractory composition which includes an outboard end portion 25 of cylindrical configuration and an inboard end portion 21 of generally conical shape. The end portion 25 extends through an opening in a refractory wall 12 of a furnace adapted to hold molten ferrous metal and the conical portion 21 projects from the inner surface or “hot face” of the wall into the furnace chamber. A temperature sensing means comprising a thermocouple 16 composed of dissimilar metals providing a hot junction at 17, encased in a ceramic tube 20, is disposed within a central bore in the protective sheath. The sheath is described as preferably of conical form and of gradually increasing cross-sectional depth from a rounded tip end 23 to its intersection with the hot face of the furnace wall at 24. This construction is said to allow continuous monitoring of high temperatures in melting furnaces for much longer periods than are possible with thermocouples in protective tubes of “heavy uniform wall thickness.”

In a modification, the sheath is mounted in a ceramic cover which fits over an opening in the furnace wall. The conical inboard portion of the sheath, rather than being located in the furnace chamber proper, is disposed in a tunnel formed by the opening, which tunnel communicates directly with the chamber of the furnace.

Claims 1 and 12 are illustrative:

1. A ceramic refractory protective sheath for temperature sensing means adapted to be inserted in a ferrous metal melt in a container, said sheath having a first portion disposed within a wall of said container and a second portion projecting beyond the “hot face” of said wall into the melt, said second portion having a substantially lesser wall thickness at its tip than at its intersection with said “hot face”.

12. A cover for a ferrous melt container having a tunnel in the wall thereof, a ceramic refractory protective sheath encasing a temperature sensing device having a portion adapted to be inserted within said melt said portion being disposed entirely within and surrounded by said tunnel, said sheath encased temperature sensing device being mounted on said cover and closing said tunnel.

Claims 2, 3, 6 and 7 differ from claim 1 in reciting at least one of certain other features, such as that the sheath is “formed of one piece”, that the inner portion of the sheath is “of generally conical exterior form”, or that the sheath is of “gradually increasing diameter from the tip to the portions thereof intersecting” the furnace wall. Claim 13 is dependent on claim 12, adding the limitation that the portion of the sheath inserted within the melt is of substantially lesser wall thickness at its tip than at its intersection with the cover.

THE REJECTION

Claims 1-3, 6 and 7 were rejected as unpatentable over Krieg² in view of Levy³ under 35 U.S.C. § 103. Claim 12 was rejected as anticipated by Levy under 35 U.S.C. § 102 and claim 13 was rejected on Levy in view of Krieg under 35 U.S.C. § 103.

The Krieg patent relates to a thermocouple well for installation in the tubes of heaters in which petroleum oils are raised to high temperatures for cracking and distillation. Figure 1 of the patent is reproduced below:

As can be seen in the drawing, forging 3 contains a passage which permits oil flow between tubes 4 and 5. Thermocouple well 8, having an internal passage 9 to receive the thermocouple wires, has an outboard end mounted in an opening in the forging and an inboard end 10 extending into the passage. The inboard end is of a tapering or generally conical shape. This shape is said to avoid “pitting, corrosion and erosion affected, by the surrounding hot oil,” that occurred in prior art thermocouple wells, which Krieg states were usually made of “a hemispherical or hemispheroidical form.” The patent to Levy discloses a thermocouple device installed in a metal-heating furnace as shown in Figure 1:

This thermocouple comprises a temperature-sensitive element encased in a ceramic tube 21. The tube extends through an opening in the furnace wall, which wall consists of a back plate 4, a heat insulating member 5 and a wall member 18. The opening in the insulating member is designated 26 and a larger opening in the member 18 is designated 27. Suitable hardware, including a nipple 32 threaded in the opening in the wall 4, seals the latter opening about the thermocouple.

With respect to claims 1-3, 6 and 7, the examiner considered that the recitations as to shape and relative thickness were met by Krieg’s thermocouple well or sheath. Acknowledging that Krieg does not specify the material of his well or sheath, the examiner regarded Levy as making it obvious to use a refractory ceramic material and to employ the resultant thermocouple end well structure in a refractory furnace.

In holding claim 12 to be anticipated by Levy, the examiner stated:

This patent discloses a ferrous melt container (13) having a tunnel (26 and 27) in a wall and a cover (pipe nipple 32). The ceramic sheath (21) has a portion adapted to be inserted within the heated area of the furnace, that portion being the section of sheath extending through and entirely surrounded by the tunnel 27. This claim does not require that the entire probe be surrounded by the tunnel * * * but merely a portion thereof, which Levy clearly shows. [Emphasis in original.]

The examiner held the additional limitation regarding the shape of the sheath in claim 13 to be made obvious by Krieg.

In affirming, the board specifically adopted the examiner’s position.

OPINION

Appellant first contends that Krieg relates to a nonanalogous art because the thermocouple well installation there disclosed is for tubes of oil heaters rather than furnaces for melting metal. In answering this contention, the examiner pointed to Krieg’s disclosure of the prevention of pitting, corrosion and erosion of the thermowell and referred to appellant’s brief before the board as pointing out that these are the same difficulties appellant is dealing with. The examiner then stated:

It is clear, therefore, that both Krieg and the appellant are dealing with the construction of thermocouples to be used in high temperature baths and since the problems involved are the same for both oil and molten metals, Krieg is an applicable reference.

The reasoning of the examiner, which is not controverted by appellant, satisfies us that it would be obvious to utilize Krieg’s teaching of a thermocouple sheath in the wall of a furnace such as that of Levy to improve performance.⁴ The selection of a ceramic refractory material such as encloses the thermocouple of Levy as the material for the well would be obvious in view of the high temperatures involved.

We also agree that Krieg discloses the structural features of these claims. Thus, e. g., the “generally conical exterior form” ⁵ of the sheath is plainly disclosed in Krieg by the description of the well as having “a taper of gradually accelerating degree, terminating in a point.” Also, Krieg’s drawing shows the tapered portion of the sheath projecting into the heated liquid material from “beyond the ‘hot face’ of [the] wall.” Moreover, Figure 1 of Krieg, supra, shows what is described as an “internal passage 9 to receive the thermocouple wires” to be in the shape of a cylindrical bore. This cylindrical shape results in the Krieg well meeting the claim requirement that the sheath have a substantially lesser wall thickness at its tip than at its intersection with the inner wall or “hot face”.

As to claim 12, we are satisfied that Levy is an anticipation substantially for the reasons of the examiner as quoted above. In particular, we find no error in the position that the portion of Levy’s thermocouple that is located within the confines of the opening or tunnel 27 shown in the furnace wall of that patent is “a portion adapted to be inserted within” the melt, since the melt would be expected to extend into the tunnel in any case where it is not closed.⁶ That portion of the Levy thermocouple is also “disposed entirely within and surrounded by” the tunnel. The hardware at the outer end of the Levy thermocouple, including the nipple 32, answers the broad requirement of a cover. Claim 12 cannot be interpreted as requiring that the tunnel be in the cover (instead of in the wall) since appellant himself does not disclose a construction which would meet such an interpretation.

It should be readily apparent that, by reading claim 12 on the Levy device, by itself, the examiner (quite properly) was indicating to appellant that the language he had chosen to define the subject matter which he regarded as his invention was so broad that it could reasonably be read to include subject matter disclosed in the prior art. As we pointed out recently, in In re Borkowski, 422 F.2d 904, 57 CCPA 946 (1970), this is but one of a number of ways in which the breadth of claim language is criticized.⁷

Claim 13, however, presents a different issue. While claim 12 is met literally by a sheath which has only an intermediate portion disposed entirely within the tunnel and the inner end extends past the confines of the tunnel, claim 13 refers to that portion as including a tip. The latter claim thus inherently requires that the tip of the sheath be within the tunnel rather than extend past it. Since that condition would not arise from merely covering the Levy thermocouple with the Krieg sheath, which the examiner suggests, the rejection of claim 13 must be reversed.

The decision is affirmed as to claims 1-3, 6, 7, and 12 and reversed as to claim 13.

Modified.

1 . Serial No. 444,668, entitled “Thermocouples” , filed April 1, 1965, in which one claim stands allowed.

2 . U. S. Patent 2,135,720, issued November 8, 1938.

3 . U. S. Patent 2,382,888, issued August 14, 1945.

4 . Appellant does argue that the rejection for obviousness in this case is refuted by an affidavit of one John F. "Wallace, submitted after appellant had appealed to the board and refused consideration by the examiner for lack of an explanation why it was not earlier presented (relying on Patent Office Rule 195 and Section 1207, M.P.E.P.). The board held this refusal of the examiner to be a matter reviewable by the Commissioner on petition and not by the board and therefore did not consider the affidavit. We find no reversible error in that position and will not consider the affidavit either. It is noted, however, that the affidavit would carry little weight in any event since it is essentially no more than the statement of a conclusion that the invention is unobvious with no supporting reasons which rebut the examiner’s reasons for holding to the contrary.

5 . This is the language of claim 3. Other claims use different language to define essentially the same concept.

6 . Levy does state that “[i]n most instances, opening 27 around the tube 21 is closed and sealed with a refractory insulation” but there is nothing to show that appellant has ever contested that this statement of a feature not shown in the drawings prevents Levy from being a disclosure of an alternative construction where the opening 27 is not closed but is open to the ingress of the melt. Further evidence that appellant recognized the presence of such a disclosure appears in the argument in his brief that “[t]he ceramic tube [21] is spaced therefrom [the back wall of the furnace and/or the back wall 18 of the muffle, which has the opening 27 therein] throughout the length therecf.”

7 . It was also observed recently that when rejections such as this, which arise mainly from the imprecise nature of the claim language, are made, it would be commendable if the specific nature of the objection were also expressly pointed out. See In re Benson, 418 F.2d 1251, 57 CCPA 797 (1969) (Dissenting opinion). Here, of course, the examiner appears to have made his objections perfectly clear by his explanation of how he interpreted the claim language.