(dissenting).
The question here is actual reduction to practice. The majority opinion, however, utilizes the legally meaningless concept of “a successful reduction to practice”* (emphasis added), which does not appear in the language of the relevant statute, 35 U.S.C. § 102(g). There are no degrees of “reduction to practice” ; either one has or has not occurred.
In determining whether reduction to practice has or has not been achieved, it is, of course, correct to consider whether acts performed in furthering the development of an invention were successful in achieving the object sought. Once it has been determined that the facts show successful testing, however, then the decision on reduction to practice and of priority of invention, pursuant to the statute, flows automatically therefrom and does not depend upon a characterization of the reduction to practice as “successful” or “unsuccessful.” Reduction to practice is a legal conclusion which flows from successful testing. There is no such thing as an “unsuccessful reduction to practice.” The only question here is whether the test results, proved beyond a reasonable doubt, meet the legal requirements for an actual reduction to practice.
As correctly noted in the majority opinion, the burden of proof appellants must meet here is “beyond a reasonable doubt.” This burden, however, runs only to what facts appellants must show to establish success of the invention and not to the process of arriving at the legal conclusion of reduction to practice to be drawn from those facts, once established. In the majority opinion this stiff burden appears to have been applied not only to the facts but, as an additional requirement, to the legal inference to be drawn from them. As a result, appellants have been required not only to make a better than normal showing of the facts relied upon but, as the majority has applied the test, have also been required to show better than normal facts. “Normal” is here used to refer to the heretofore existing legal requirements which we should follow. The effect here has been that appellants have been required to prove a higher standard of operative perfection of their invention, namely commercially satisfactory operation, than has been normally required to establish reduction to practice. Such a result is clearly inconsistent with decisions by this and other courts that less than perfect operation will establish reduction to practice, e. g., Kravig v. Henderson, 362 F.2d 1015, 53 CCPA 1534 (1966); Eastern Rotorcraft Corporation v. United States, 384 F.2d 429, 181 Ct.Cl. 299 (1967); Schnick v. Fenn, *263277 F.2d 935, 47 CCPA 1174 (1960); and Leichsenring, Jr. v. Freeman, 103 F.2d 378, 26 CCPA 1153 (1939).
In Leichsenring, for example, a hydraulic automobile braking device tested had been shown to hold the vehicle stationary even though it was an admitted fact that a leakage of brake fluid occurring when the brakes were applied would, after a while, result in release of the brakes. Although this defect in a vehicle brake system might seem to some a more serious failing in relation to the respective inventions involved than the presence of some streaking by a floor care machine, the court in Leichsenring held, in unanimously reversing the Patent Office, that there was a reduction to practice, stating:
The question is, did the tests demonstrate the device to be successful? That Exhibit 2, in the condition in which tested, would not have been commercially satisfactory is obvious, but it is well settled that there may be a reduction to practice by use of a device not commercially successful. * * ******
It was clearly demonstrated, we think, that-appellant’s device involved the generic principle, and that it worked for a sufficient period of time to show that the application of the principle solved the problem. * * *
[Emphasis added.]
Similarly in our more recent Schnick case in which we found reduction to practice of a cigar-lighter invention despite the fact that the test- results would not have warranted production of the lighter at that time, we said:
It must be remembered that Fenn and his associates were extremely experienced in this field and once they found the basic concept of the invention to be sound by testing it their principal concern was dissipated because they knew that the refinements necessary to perfect a commercially acceptable device could be made in the usual course of preparing it for mass production. * * *
[Emphasis added.]
In Eastern Botorcraft a unanimous seven-judge United States Court of Claims said:
Reduction to practice occurs when the workability of an invention can be demonstrated. Workability means that a physical form of the invention has been constructed which functions. * * * And this requires testing the invention. * * * the inquiry is not what kind of test was conducted, but whether the test conducted showed that the invention would work as intended in its contemplated use. * * Proof of the invention’s utility for its intended purpose does not require proof of its flawlessness; it is . only necessary to show that the invention is able to perform its intended purpose beyond a probability of failure. [Emphasis added.]
Most of the several cases relied on in but omitted from the above quotation are decisions of this court.
The rationale of prior decisions is that if tests show that the device tested functions in such a manner as to demonstrate the soundness of the principles of operation of the invention, then there has been a reduction to practice, even though continued refinement of the device within the skill of the art is necessary before the invention is in a commercially exploitable form.
Turning to the present case, the correct approach, therefore, is to apply the “beyond a reasonable doubt” test only in determining whether the facts proved by record evidence showed that appellants established the soundness of the principles of operation of their machine, Exhibit 5. Once the facts have been established, it follows as a legal conclusion that there has been a reduction to practice of the invention.
Considering, first, exhibit 157, it will be assumed, arguendo, that it is not available to appellants as evidence to show what it reports. Even without the benefit of exhibit 157, however, there is adequate testimony in the record to show facts from which a conclusion of reduction to practice follows. The testi*264mony to be considered divides into two aspects: (1) what operations were performed by the Exhibit 5 device and (2) whether the tests on the Exhibit 5 device show the soundness of its principles of operation. As the majority states, it is not questioned that Exhibit 5 meets the terms of most counts, was built, and was tested at an early enough date.
The operations performed by the Exhibit 5 device in the period about January 1961 are described with relation to the functions that were carried out during operation of the device by the witness Clowers, as follows:
Q38. When you first saw this unit, Mr. Clowers, did you see anyone operate it, or have you ever operated it yourself, and about when did that happen? A. As I recall, it was approximately the two month date after I started [November I960]. The machine was operated. Liquid was dropped from the containers and it was also picked up with these squeegees.
Q39. Where was this done, if you recall ? At someone’s home, or where ? A. The demonstration I saw was down in our room where we work downstairs where the Motor-Operated Appliances Division is on the first floor.
Q40. Do you remember who was doing the operating? A. Both Mr. Ernstberger, Mr. Ritter, and myself.
Q41. Mr. Clowers, could you look at this unit closely and tell us if you remember it as being the same unit that you saw after you started to work here? A. Yes, I would say so, because of this tube here. As I recall, there was only one model of this made. Perhaps there were more, but I didn’t see them. I only saw this one. This is the one I saw.
Q42. This the machine you saw? A. Oh yes, the silicon — rubber—definitely the identical machine I saw. The epoxy, of course, was hand work.
Q43. Did you ever operate the machine? A. At this time I operated this machine.
Q44. Did you understand its parts when you operated it and its mode of operation? A. Yes, I did. As I recall, it was very easy to control. It was like our standard floor conditioner.
Q45. Could you quickly tell us how it did operate at that time? A. To dispose the water, this control was used up on the handle here with this tank assembled. When this is brought back, this lever comes up and activates the valve which drops water into this trough which was disposed into a tube onto the floor. With the motor running and the brushes rotating, they would scrub the floor. This had to be rotated if you wanted soap. A cam rotated by hand would allow soap to flow into the channel and mix with the clean water on the floor. As it scrubbed, by activating this lever here—
Q46. A foot lever? A. A foot lever, we could drop the two squeegees onto the floor and then a vacuum would pick up the water that was brushed and squeegeed by the rubber blades. That would suck this up through the tube and deposit it in the tank.
Q47. Could you tell us the suction path? A. These two come together at the point that we see here.
Q48. In this Y-shaped fitting? A. In this Y-shaped fitting. This in turn is the return of the air coming through.
Mr. Lewis: I can see we have taken this apart.
By the Witness:
A. (Continuing) We are taking the vacuum from the motor through the larger tube.
In turn this is being pushed up by atmospheric pressure into the tube on the tank. The large tube is clean air; the small tube carries the dirty water and air mixture.
By Mr. Lewis: Q49. After the dirty water came up into this small tube, where would it go ? A. It *265would hit this surface here and be deflected downwards.
Q50. This clear surface of plastic? A. Yes, the water and air mixture. It would be directed down so it didn’t splatter back into the clean air system. This way the water would be deposited in the bottom and the air was free to come back up and flow through here and return.
Q51. Where would the waste water, the dirty water be stored? Where would you get this fresh water or cleaning water? A. The clean water would come from this valve, which also comes loose so you can refill this container. The dirty water was deposited through here and also had to be emptied from this same opening in this fashion. This part snapped into here and fits back, being held in place by the upper member. It also is guided by the member that is keyed to fit in there. [Emphasis added.]
It can be observed from this testimony by a witness who was neither one of the inventors nor an employee of Sunbeam at the time of taking the testimony, that the Exhibit 5 device in January 1961 performed the operation to be expected of a device meeting the limitation of count 1, namely depositing water on the floor, scrubbing the floor, picking up the water by vacuum, and separating the water from the air.
It follows that the next question to be decided is whether Exhibit 5, functioning in this manner — and there is nothing in the record that would indicate that it might have any different range and sequence of operations when operated by other people than Clowers —satisfactorily demonstrated the soundness of the principles of operation underlying the invention. The co-inventor Ernstberger stated:
Q375. This unit [Exhibit 5] that your entry says was finished on January 13, 1961, did you use the unit personally? Did you scrub a floor with it? A. Oh, yes.
Q376. Did you pick up water? A. Oh, yes.
The co-inventor Ritter stated:
Q213. Was the unit finished when you stopped working on it? A. Yes, I could demonstrate its working features.
Q214. Did you use it? A. I many times demonstrated it to various people who either supervised me or have an interest in it.
Q215. Did you scrub any floors with the unit ? A. I did many times.
Q216. Did it work well? A. It worked very well.
In addition, the co-inventor Wolter, who also operated Exhibit 5, testified that the unit also functioned fairly well despite certain imperfections, thus:
Q151. Do you have any recollection of operating this unit, No. 5? A. Yes.
Q152. Do you have any recollection of demonstrating this unit to anyone? A. Yes.
Q153. Could you remember to whom you demonstrated it? A. Well, again I am sure Mr. Jepson is one. I believe Mr. Hegerieh, and possibly Mr. Lee.
Q159. Were you satisfied with its operation? A. Not entirely. Do you want me to go into detail on it?
Q160. If you can remember something that you thought. A. Well, functionally it seemed to work fairly well. We were not entirely satisfied with our water separation as I recall in this unit. We were not satisfied with the hose arrangement. We had developed a hose within a hose. The problem of separating dirty water from clean, and the problem of separating foam from the air was not entirely satisfactory in that unit.
Q161. What about the cost of this unit ? Did you have any attitude about the cost? We felt it was too high. Our goal was lower than we thought this would come out to be. Actually, concerned with cost at this point, being a breadboard, we weren’t too but concerned with function.
*266Corroboration is supplied by Jepson and Hegerich identified in the above testimony of Wolter. Jepson’s testimony included :
Q27. Mr. Jepson, Exhibit No. 5, did you see it in operation at all after it was completed? A. Yes, I am sure I did.
Q28. Did you operate it at all? A. Yes.
Q29. Can you remember if you used it? A. Yes. I did use it.
Q30. Did you think it did a good job of scrubbing the floor and picking up water? A. Well, it did a good job so far as I can recall, but I know there was quite a few little details that I thought should be improved on, but in general I thought the principle was sound.
Hegerich, in a letter written on March 8, 1961 (Exhibit 277) wrote:
“Some weeks ago I watched a demonstration in R & D on a deluxe floor polisher — scrubber and water vacuum. This working model performed beautifully. The dispensing, scrubbing, etc. was deluxe in every respect. The water vacuum was superb and dried the floor very satisfactorily. Unlike all the other water vacuum competitive units I’ve seen demonstrated, this unit did the job.
“In my opinion, this unit should be our deluxe floor conditioner and water vacuum.”
Moreover, Hegerich’s letter recommended that the project be pushed ahead and expedited with a target date of March 1962 for marketing, a step which he would hardly have taken had he just observed a test of a device which was a failure.
The foregoing testimony of the numerous inventors and corroborating witnesses establishes beyond a reasonable doubt that the tests of Exhibit 5 showed to the satisfaction of all who observed them that the device demonstrated the soundness of the underlying principles of operation of the invention, and that though there may have been some imperfections they were only such as could be eliminated in the usual refinement of a prototype device into a commercially salable embodiment.
Applying to the fact situation thus established the rationale of the Leichsenring and other cases previously discussed, a legal conclusion of reduction to practice necessarily follows.
Accordingly, as I find that appellants reduced their invention to practice prior to the appellees’ filing date and are, therefore, entitled to an award of priority, I would reverse the decision of the board.
Although this expression appears in Land v. Regan, Jr., 342 F.2d 92, 52 CCPA 1048 (1965), at [4], the context clearly shows what was there intended by “successful reduction to practice” (emphasis added) was “actual reduction to practice.”