et al." ** We do not dispute this, but it is a result that is inherent in an obvious variation of the working examples of the reference. Note In re Libby, 45 CCPA 944; 1958 C.D. 324; 733 O.G. 294; 255 F. 2d 412; 118 USPO 94.

We recognize that all the claims require that the aqueous phase remains acidic, whereas the reference neutralizes this phase. We are not convinced by the record that this difference, which can be only a very slight amount of acid in the aqueous phase, assures an unobvious result.

The board also felt that the step which dependent claim 8 added to its parent claim 1 was shown by Stanley.

Appellant's request for reconsideration, based on the argument that he discovered that the melting point of DPP is reduced in his system, was denied thusly:

Since merely reducing the amount of solvent in the reference process would produce the wholly liquid system defined in the claims, all steps and conditions of the claims would be satisfied. It is therefore patentably immaterial whether the DPP dissolved or melted.

Appellant's position that the rejections are founded on reconstruction of the art based on hindsight gained from his disclosure includes the specific argument that his process is based on the

recognition of the fact, apparently not appreciated or understood by Grimme et al., that when diphenylol propane is mixed with water and selected solvents the melting point of diphenylol propane is greatly reduced from the melting point (about 150° C.) of dry diphenylol propane so that a wholly liquid system can be formed from such mixture at a temperature below the boiling point thereof (in the range between 70° C. and 100° C.) even though the amount of solvent in the mixture is far less than that required to dissolve the diphenylol 本本串。 propane

In view of the foregoing, it is said, appellant's solvents are not selected on the basis of high solubility therein of DPP at the boiling point, as in Grimme, but rather on the basis of their ability to substantially reduce the melting point of DPP in the mixture. In fact, appellant's solvents are selected to have as a characteristic poor solubility of DPP so that only a small quantity of DPP is taken up in the organic phase of the mixture, with the result that the risk of decomposition, absent prior neutralization, during recrystallization is avoided.

It is urged that the claimed process is distinguished from the Grimme process in the following particulars:

1. The heated mixture has therein the acid containing reaction product and there is no prior neutralization of the reaction product as in Grimme et al.;

2. The maximum amount of the diluent or solvent in the mixture is 400% of the amount of diphenylol propane, whereas, in Grimme et al., the amount of the solvent is at least 450% of the amount of diphenylol propane; and

3. At least 20% of the organic, solvent-containing phase of the wholly liquid system is constituted by diphenylol propane, whereas, in Grimme et al., no more than 17-18% of the organic layer can be constituted by diphenylol propane.

Finally, appellant argues that several of the solvents specifically mentioned by Grimme, such as benzene and chloroform, are unsuitable in appellant's process due to the fact that the amounts of such solvents required to form the wholly liquid mixture are in excess of the 400% of the amount of DPP claimed. Appellant admits, however, that the solvents toluene, chlorobenzene and 1-2-dichloroethane (ethylene dichloride), specifically mentioned by Grimme, are included in the Markush group of appealed claim 1.

The solicitor counters by emphasizing the breadth of claim 1 in pointing out that the use of 400% of organic solvent, as permitted by claim 1, will result in dissolving over 66% DPP when monochlorobenzene is used and over 80% DPP when ethylene dichloride is used. Thus, it is urged, claim 1 permits a major portion of the DPP to be dissolved in those instances contrary to appellant's alleged objective rendering the alleged advantage of lesser amounts of solvent irrelevant. Moreover, it is argued, Grimme discloses a process embodiment wherein neutralization occurs subsequent to mixing and prior to heating and claim 1 does not exclude neutralization in that it recites "steps *** comprising" thus leaving the claim open to other steps, while claim 4 calls for neutralization prior to crystallization as disclosed in the application.

While we are favorably impressed with appellant's arguments pointing out those instances where the amount of solvent required to provide a wholly liquid mixture with DPP in his process is considerably less than the amount of solvent required to dissolve the DPP therein, as disclosed by Grimme, the breadth of claim 1 requires that we focus our inquiry on the question of whether it would be obvious to one having ordinary skill in the art to employ an amount of solvent which is less than that amount "which is sufficient to completely dissolve the diphenylolpropane" as fairly disclosed by Grimme. When ethylene dichloride is employed, these amounts are 400% and 450%, respectively, for appellant's process and the process of the reference. Considering the record, we find that the Patent Office's allegations regarding a "common, routine expedient," the "expected skill of the art to determine optimum proportions" or the belief "that workers in the art would recognize that solubility values *** are rarely the same," true as they may be, are nevertheless unsupported by sufficient facts to overcome the strong suggestion implicit in Grimme that the minimum amount of solvent usable is that quantity which dissolves the DPP. Thus, the reference states:

The quantity of the solvent used is variable, but at least such a large quantity is to be used which is sufficient to completely dissolve the diphenylolpropane. The use of an exceeding quantity of the solvent is not injurious.

As to limiting the amount, Grimme mentions only:

In order to limit the quantity of solvent required, the solvent should preferably furthermore have a sufficiently great dissolving power for the diphenylol propane while hot or at the boiling point.

Clearly, Grimme does not teach the approach taken by appellant. In the absence of a factual basis for the Patent Office's allegations that that approach with its inherent results would be obvious, we are constrained to agree with appellant. The view we take of claim 1 is also dispositive of the remaining dependent claims.

The decision of the board is reversed.

416 F.2d 1322; 163 USPQ 417

IN RE THOMAS B. MCGUIRE AND ANDREW POGAN (No. 8189) PATENTS

1. PATENTABILITY-ANTICIPATION-KNOWLEDGE OF PRIOR ART PRESUMED; PATENTABILITY-ANTICIPATION-PATENTS-OLD PATENTS; PATENTABILITY-EVIDENCE OF-DELAY AND FAILURE OF OTHERS TO PRODUCE INVENTION

Applicants' argument based upon century-old status of reference patents does not impress court, absent showing that art tried and failed to solve some problem notwithstanding its presumed knowledge of references.

United States Court of Customs and Patent Appeals, October 23, 1969* Appeal from Patent Office, Serial No. 375,217

[Affirmed.]

Bruce B. Krost, Woodling, Krost, Granger and Rust, attorneys of record, for appellants.

Joseph Schimmel for the Commissioner of Patents. Lutrelle F. Parker, of counsel.

[Oral argument October 8, 1969 by Mr. Krost and Mr. Parker]

Before RICH, ALMOND, BALDWIN, LANE, Associate Judges, and GANEY, Judge, sitting by designation.

RICH, Judge, delivered the opinion of the court.

This appeal is from the decision of the Patent Office Board of Appeals affirming the rejection of claims 5, 10, 11, 13, 17, 19, and 21 of application serial No. 375,217, filed June 15, 1964, entitled "Tool for Internally Cutting a Tube at an Angle to the Axis Thereof." Five claims have been allowed.

The claimed invention is a tool used for cutting tubing or pipe, such as copper tubing used as water lines in buildings. Appellants' brief informs us that conventional plumbing procedure calls for the rough installation of lengths of tubing in the open walls and spaces below the floors of buildings under construction such that the ends of the

*Petition for rehearing denied Dec. 4, 1969.

individual lengths extend slightly beyond the points where connections are ultimately to be made. Subsequently, it is necessary to cut off the excess tubing at the exact location where an "" or "T" fitting, for example, is to be introduced. It is this cutting-off operation for which appellants' tool is said to be particularly well suited.

Setting the stage for a description of the claimed tool, appellants' brief states the following about certain prior art pipe and tubing cutting tools and the alleged shortcomings thereof:

The customary tool used in the plumbing trade for cutting off the "throw-away" piece is an external cutter *

A typical external cutter has a C-shaped member that embraces the tubing and which carries rotatable disk cutters directed inwardly toward the outer wall of the tube. The C-shaped member usually has a handle extending outwardly and by manually revolving the C-shaped member carrying the cutter disks around the tube, the cutters cut into the outer wall of the tube. Means are provided on the C-shaped member for gradually moving the cutter disks toward each other against the tube as they progressively cut into the tube wall during revolving of the C-shaped member around the tube.

There are distinct disadvantages in the use of such external cutters. First, very often there is not sufficient space around the outer wall of the tube to swing the cutter therearound. Sometimes, the tubing is extending alongside and very closely to a floor joist ***. Sometimes, the tubing is extending up from a floor in the corner of a room too close to the walls for the revolving of the external cutter.

Heretofore, in such tight situations plumbers have sometimes laboriously used a hack saw, but this is awkward and difficult in a cramped and confined space. Worse still, the hack saw mutilates, pinches and chews up the end of the tubing where cut, particularly the relatively soft copper tubing commonly used in installing water lines in a building. This requires considerable secondary operations on the tubing at the location of the saw cut, such as reaming it out to bring it back to cylindrical shape, removing burs and slivers, and trying to restore the cut end of the tubing so that it will fit readily and properly into the cylindrical socket of a coupling, “L” or “TM” fitting for connection to another length of tubing. The external cutters have been the customary and standard tool used by plumbers for cutting off these end portions of tubing, notwithstanding their limitations on use in confined and restricted space. However, they have other serious shortcomings, such as the pinching of the metal wall of the tubing inwardly as the disk cutters progressively cut into the tube wall. This is particularly true of the softer metals such as cooper, brass and aluminum, and which are now commonly used in installing lines in a building, such as water lines and electric cable conduits. This pinching in of the tube wall where cut seriously decreases the internal diameter of the tube and leaves a burred, rough edge directed inwardly of the tube. This necessitates the subsequent reaming out of the tube at the location of the cut to try to bring it back to its original true cylindrical form, and to remove the burs and sharp edges at the location of the cut. ** For the tube end to fit readily and properly into the cylindrical socket of a coupling, "L" or "T" fitting, it should be a true cylinder free of burs and the like. Another approach has been tried out for cutting a tube, this being by means of an internal cutter. Such an internal cutter has been the type that has been used for cutting out steel tubes in a steam boiler in the removal of deteriorated steel tubes from the steel walls of the boiler in its renovation. In such internal

cutters used for cutting the boiler tubes, a shaft was inserted into the open end of the tube from outside the boiler. The shaft carried either cutting disks or a cutting blade which was forced radially outward against the inner wall of the steel tube. The direction of the travel of the cutters was radially outward in a plane normal to the axis of the tube and of the shaft. As the shaft was rotated on its axis, the cutters would revolve around the shaft axis against the inner wall of the tube and progressively cut directly into the tube so as to sever it from the boiler wall.

A very serious shortcoming of such internal cutting tools that had been used for cutting steel boiler tubes was that when the tool was utilized on copper, brass, aluminum, and other soft metal tubing, the cutters bellowed out or beaded the metal wall as they cut the metal. This resulted in a bell or flare on the end of the tubing where cut. Such a belled or flared end would not fit readily or properly into the cylindrical socket of a coupling, "L" or "T" fitting as required. *** As a result, the plumbers usually preferred and used the external cutters with all of the shortcomings of the same. Although the boiler-tube internal cutters were old and well known, they did not become accepted to any extent in the plumbing industry dealing with tubing of the softer metals because of the described serious disadvantages and limitations of the internal cutting tools used for steel boiler tubes.

The claimed tool and the progressive steps in a cutting operation using it are shown in the following three figures from appellants specification:

A shaft 12 is inserted into the open end of tubing 11 to a depth that is determined by adjustable collar 18. Shaft 12 has a transverse slot 13 extending therethrough at an acute angle (such as 45°) to the axis of the shaft and tube. Disposed within slot 13 is a cutting bit 29 slidable therealong to move in a corresponding angular path.

A rod 23 extends through an axial opening 14 in shaft 12, the