The opinion
RICH, Judge,
dissenting, with whom SMITH, Judge, joins.
The structure of the invention and the disclosure of the closest prior art, the patent to Simpson et al., No. 3,050,346, are adequately described in Judge Almond’s opinion. The only issue in this case is obviousness under 35 U.S.C. § 103 . This is a case in which we clearly must be wary of making a judgment of obviousness on purely theoretical considerations and heed the voice of experience as it speaks to us from the record. We must also try to avoid hindsight reconstruction of prior art disclosures in the light of appellant’s teachings.
Caterpillar Tractor Co., the leader in the field, well-knowing the need for a track ink seal and what it must accomplish, devised the Simpson seal. In theory it would appear to solve the sealing problem. Its Simpson patent states:
Wear of the ends of the bushings and the inner faces of the recesses 17 * * * is also eliminated because the washers 18 do not rotate relative to the bushing and the recess. All tendency toward wear in this area is between the hard faces of the washers 18 and is greatly minimized because of their hardness and the inability of abrasive materials to enter between their contacting surfaces. [Emphasis added.]
This appears to have been theorizing on the part of Simpson, or his patent solicitor. It also appears to have been erroneous.
Applicant, head of the engineering department of WesTrac Company, assignee of the application at bar and largest independent manufacturer of replacement parts for tractor tracks in the United States, has filed an affidavit reciting the following facts:
The principal portion of the business of WesTrac is supplying replacement parts with [for?] worn Caterpillar tractors. Recent models of Caterpillar tractors use the structure shown in * * * Simpson Patent No. 3,050,346. In the course of affiant’s duties, he has *1017 had occasion to examine many worn Caterpillar track links and determine the cause of failure thereof.
In a substantial number of worn Caterpillar tracks, it has been found that the counterbore of the outer link has become scored by turning of the sharp outer edge of the adjacent Belle-ville washer indicated by reference numeral 18 in Fig. 1 of Simpson. Such washer 18 is of a very hard material whereas the link boss 16 is of a relatively soft material and any turning movement of the sharp corners of the washer results in a scoring of the bottom of the eounterbore.
Accepting these facts, as the majority opinion does, it follows that in a “substantial number” of cases Caterpillar’s Simpson seal fails to operate as intended, or as it is supposed to operate in theory, and one is forced to the inevitable conclusion that solving the problem of sealing this particular tractor tread joint is not as easy as it looks. Simpson did not solve it with his invention and he had available to him Burgman’s disclosure of rubber seals faced with flat washers as wearing surfaces. Burgman’s patent issued Sept. 29, 1959. Simpson did not file until Jan. 24, 1961. Burgman was no help to Simpson. Equally, his teachings are of no help in curing the defects of Simpson’s seal.
The majority also expressly accepts the showing of Hayatian’s affidavit that the theory of Simpson’s patent is fallacious, at least in a substantial number of cases where grit gets between his Belle-ville washers, causing them to rotate together. The affidavit showing on this matter is as follows:
Theoretically, the two Belleville washers 18 of Simpson should turn relative to each other rather than relative to the link and relative to the bushing 13, and hence theoretically the washer should not dig into the bottom of the counterbore. However, in practice, in a substantial number of cases, it has been found by affiant that for some reason such as the lodging of abrasive material between the two Bellevilles, sufficient heat generated by friction between the rotating parts, or for some other reason, the two Bellevilles “freeze” relative to each other and no longer turn. When this happens, the Belleville washer 18 at the top of Fig. 1 tends to dig into the soft bottom of the counterbore and to score the bottom of the counterbore. When this occurs, the space between the end of the bushing 13 and the bottom of the counterbore effectively increases, thereby reducing the resilient effect of the seal and lessening the seal. Further such scoring of the bottom of the counterbore provides a passage whereby the abrasive material can bypass the seal and get into the bottom of the counterbore, pin 14, and bushing 13, and soon bring about the destruction of the link seal. [Emphasis added.]
The alleged obviousness here is predicated on the disclosures of the Simpson and Burgman patents and on nothing else. But it seems clear that from reading the Simpson patent it is not even known how the Simpson seal actually operates in practice or what its defects are. Appellant, due to his advantageous position in this art, made his invention in three steps. First, he discovered what the defects of the Simpson seal are; second, he reasoned out what the causes of those defects are; third, he devised a different combination of old elements which would avoid those defects. I am unable to see wherein what he did was obvious in the sense of 35 U.S.C. § 103 .
The legal defect of the majority opinion is the same as that of the examiner and the board. All three proceed on the premise that appellant may have his patent if he supplies persuasive evidence of the superiority of his seal over that of Simpson’s. Such proof is demanded, of course, on the premise that appellant’s seal is prima facie obvious from the references, which I find not to be the case. The record here shows very clearly that even the defects of Simpson which started appellant’s inventive process were anything but obvious. Appellant’s invention resides as much in finding the cause of the problem created by those defects as in overcoming it. How, then, can the invention “as a whole” be obvious, as required by section 103?
Since there is no prima facie obviousness, it is beyond legal propriety for the Patent Office to demand evidence of superiority over Simpson. As a practical *1018 matter, it should also be considered what is entailed in supplying such evidence. It can be presumed that Caterpillar tractor tread linkages in such a commercially successful tractor as is produced by Caterpillar do not wear out except after considerable use. It can be further presumed that it would take at least as long to prove superiority of appellant’s seal construction as it would to develop, through use, the defects in the Caterpillar Simpson seals. Since only a “substantial number” of Simpson seals— whatever that may mean — develop the defects recited in the affidavit, it would further require that appellant install his seals in a statistically significant number of tractors and somehow manage to get them into parallel service with an equal number of otherwise identical tractors having Simpson seals, running them under a kind of test-track supervision until a “substantial number” of the Simpson seals have been found to break down and then tear down his own seals to find out how much they have worn in comparison. It seems to me that to demand this kind of evidence is to demand the impossible. It might take years, if we assume it is practicable at all, and where, meanwhile, has the Patent Office prosecution gone?
On its face, appellant’s proposed solution appears to be a workable one and an advance in the art. He should have his patent with his single claim. Should it turn out that his seal is not in fact superior, after a number of years of trial, only his assignee will be the loser. Certainly the public will not be injured by another patent on a commercially unsuccessful device. On the other hand, if it turns out that appellant’s seal is superior in fact to Simpson’s in accordance with appellant’s educated belief, then his assignee should be protected from imitation without compensation. Such prospective commercial success is a “secondary consideration” indicative of patent-ability. Graham v. John Deere Co. of Kansas City, 383 U.S. 1 , 86 S.Ct. 684 , 15 L.Ed.2d 545 (1966).
The theoretical arguments advanced by the solicitor and accepted by the majority based on Coulomb’s second law of friction, like the theories in the Simpson patent, are as much open to question when they come to be tested against the operation of tractor tread link joints in mud, dust, and sand where theories based on laboratory experiments do not seem always to work out in practice. This argument is an afterthought to bolster up a legal argument and entitled to little weight. Even if the theory worked out in practice and the flat washer rotated contrary to appellant’s theory, it seems evident that it would not cut the groove in the bottom of the counterbore cut by the edge of a Belleville washer and so would not open up the seal as does the Belleville, beside which grit under the flat washer might cause it to stand still in spite of Coulomb’s second law of friction. One theory seems to be as good as another — and as useless — in this area and I think we should be practical and listen to the only expert who has had anything to say of record, the appellant.
For the above reasons I would reverse.