Court Opinion

ID: 9442754
Source: CourtListenerOpinion
Date Created: 2023-08-03 18:58:29.479244+00
Date Added: 2024-06-11T17:29:13.121131
License: Public Domain

CHASE, Circuit Judge,
dissenting in part.
This appeal is from a decree in a suit for the infringement of two patents, one, No. 2,115,423, issued to C. Korver on April 26, 1938, for a “Method and Device for Transporting Wires,” and the other, No. 2,162,847, issued to the same patentee for a “Flash Lamp.” The first patent is for a process used in the manufacture of the flash lamp which is the product covered by the second patent, and they will hereafter be called respectively the process patent and the product patent. Some of the claims of the process patent were held invalid. Those have all since been disclaimed and are not now involved. Others were held not infringed. All the claims of the product patent were held valid and infringed; an injunction was granted and an accounting ordered. The plaintiffs are the Wabash Corporation, exclusive licensee under both patents, and the Hartford National Bank and Trust Company, which holds the legal title to both patents in trust. They have appealed from so much of the decree as holds the process patent claims not infringed. The defendant Ross Electric Corporation which sells the accused lamps in the Eastern District and the defendant General Electric Company, which manufactures and distributes those lamps for sale, have appealed from that part of the decree which holds the product patent valid and infringed.
*579The flash lamps are the kind known as photo-flash lamps. The development of such lamps began with a type made by the General Electric Company under the Oster-meier patent, No. 1,776,637, about twenty years ago, and has marked a decided advance in the art of flash photography. Before then, the necessary intense light of short duration was provided by igniting fast-burning powders in open containers, creating smoke that was more or less disagreeable to the senses and somewhat of an interference with taking a succession of pictures. Ostermeier did away with all that by providing a glass bulb filled with oxygen and aluminum foil in such a way that an electric current, entering the bulb, would ignite the filling. An intense light of sufficiently controlled duration but with a sharp peak, i. e., a comparatively short period of highest intensity, could be obtained from his lamp. Yet his great advance over what had been done before left much to be desired. The shortness of the period of maximum light output made synchronization with the camera shutter difficult, his bulbs had to be so large that a photographer could readily carry but a few at once and they had to be handled with much care to prevent breaking. Their manufacture was made slow and costly by the necessity of filling the bulbs with the right amount of the right size of foil by hand, by pushing it in with a rubber-tipped rod such as a pencil with its eraser, to insure its uniform distribution in a crumpled condition throughout the bulb. Still this lamp was such an improvement over the old open flash method that it was in great demand and in 1938 nearly 4,000,000 were sold.
In 1936 the predecessor of Wabash Corporation, having obtained an exclusive license under the patents in suit, began making the patented lamps. They were so much cheaper to make, so much more efficient in operation, and in other respects so much better than the Ostermeier lamps that the latter were superseded in a few years. In 1942 over 17,000,000 of the patented lamps were sold and in 1948, over 60,000,000. In 1942 General Electric began to make and to market the accused,, lamps, and their sale has nearly equalled that of the patented ones. Though some of this marked commercial success may be justly attributable to factors independent of the disclosures of either of the patents in suit, it is apparent that those disclosures were in large measure responsible for it.
The Process Patent
While the process patent originally covered more, the elimination of the claims as above noted narrowed it to a method usable only in filling containers shaped in general like the bulbs of photo-flash lamps. Claims 2, 5 and 6 were held valid. Claim 2 is typical and reads as follows: “A method of uniformly filling a hollow body closed except for a single aperture, with an internally-strained wire of small mechanical strength, comprising the steps of carrying the wire through the aperture and into the hollow by a stream of gas leaving through another portion of the aperture, and distributing the wire in a curled condition and as uniformly as possible within the hollow by the recurrent flow of the gas therein.”
I will confine my description of the process to one, as disclosed by the specifications, which is usable for filling photo-flash lamps, since the accused process is of that kind and the patentee called his “particularly well adapted” for that.
Whenever a metal wire1 is bent the stretching which occurs on the outer side of the bend and the compression on the inner side so distort the metal that internal strains are set up. These strains have a tendency to make the wire curl when it is not under tension, the amount of curling varying directly with the intensity of such strains. Most metal wires of small absolute strength are inherently so strained that they have some tendency to wave or curl when loose, and winding on a spool serves to increase this tendency. Korver sought to fill a photo-flash bulb with such *580wire mechanically so that it would be evenly distributed throughout the bulb and would be so curled and waved that it would be held in place during handling and use by its resiliency against the walls of the bulb and between cu-rls throughout its own mass. He did that by assembling a machine which first unwound from a spool the fragile wire when it was to be used for filling. If it was not already sufficiently internally strained to curl as desired in the bulb, the wire was pulled over a sharp edge to impart such strains. Then it was carried to, and through, a guide tube of small diameter which extended into the aperture of the bulb which was of much greater diameter; there the guide tube was greatly enlarged in diameter but still kept much smaller than the neck of the aperture. A supply of compressed air was fed into the guide tube near the end where the wire entered, this being done in such a way that the air would flow toward the bulb; This air stream carried the fragile wire along the small part of the guide tube under sufficient tension to keep it from curling or kinking during that transit but when this stream reached the enlarged or “belled” portion of the guide tube, within the neck of the bulb, the air expanded and was thus slowed in speed enough to let the wire curl. From there the air stream, slowing even more after it entered the larger portion of the bulb to be filled, distributed curled wires throughout the receptacle by flowing to and against the closed end of the bulb and then reversing and passing out of the bulb through the aperture between its inner sides and the outside of the guide tube. This reversal of the direction of the air flow and its passage to, and out of, the aperture of the bulb is what is designated in Claim 2 as “the -recurrent flow of the gas” which distributes “the wire in a curled condition and as uniformly as possible within the limited space.”
In the accused process the material from which the filler is made is not at the beginning a fragile wire wound on a spool. It is, instead, a roll of aluminum foil of the desired thickness and width. It usually is about eight inches wide and .001 of an inch thick. This sheet of foil is unwound from its roll by feed rolls between which it passes. These feed rolls first draw it through a lubricating tank, where it is treated to make it shear more readily, and then push it over a shear plate. There a rotary cutter, synchronized in speed with the rate of travel of the sheet of foil, slices off narrow strips of a pre-determined width.2 Suitably placed below these -rotary shears is the flared-out end of a small hollow tube. This tube leads to a filling head with which it makes an air-tight connection. The filling head has an outside rim into which a photo-flash bulb may be placed so as to make an air-tight connection between the filling head rim and the outside of the bulb at some part of it between the neck and the point of the maximum diameter of the bulb. The inside of the filling head forms an extension of the carrier tube and has its outlet near the center of the bulb to be filled. Above the bottom of the carrier tube there is an opening in the side of the filling head which has an air-tight connection with a trap which is in turn connected to an exhaust pump. This pump tends to create a vacuum at the intake end of the carrier or feed tube into which there is a rush of the air which surrounds the shreds as they are cut off. As the trial judge justifiably found, “The shreds are sucked into the feed tube at such high velocity that the naked eye cannot see their condition as they are drawn into and through the nozzle. However, they are probably drawn into the feed tube in ‘hairpin’ form, and are carried by the stream of gas through the filling tube and are kept fairly straight until they reach the bulb of the lamp. There the successive shreds strike the bulb wall and intertangle with one another to form a tangled, skeletonized mass of curled, crinkled or rumpled material within the bulb. The bulb is then removed from the filling tube and placed over an air jet which serves to fluff the material and to distribute it uniformly through the bulb.” The judge *581also found on adequately supporting-evidence that, “Unlike Korver, the General Electric filling method does not deal with or produce a wire which has been internally-strained so as to assume a curled or coiled condition when released.” And that, “The General Electric filling method does not uniformly distribute the shreds as called for in the Korver patent. A separate fluffing operation with a jet of compressed air * * * is necessary to obtain uniformity in the General Electric operation.”
These differences between the two processes were considered by the trial judge sufficient to preclude infringement, and I agree. Though they may appear to be but narrow distinctions I think that in the light of the prior art they are crucial.
But before taking up that phase of the matter I wish to notice that the decision below apparently followed the “better practice” as pointed out in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 330, 65 S.Ct. 1143, 89 L.Ed. 1644, by dealing with the validity of the claims before deciding the question of infringement. The three claims remaining after those held invalid had been disclaimed were what I might call tentatively held to be valid and then held not infringed. That entirely disposed of the suit on that patent and the decree as to it provided for the dismissal of the complaint without adjudging the three remaining claims to be valid. Thus there was an investigation and determination as to validity to comply with the above mentioned better practice, which the record affirmatively disclosed, without the error of adjudging any claims valid which, even if valid, would not have been infringed. Electrical Fittings Corp. v. Thomas & Betts Co., 307 U.S. 241, 59 S.Ct. 860, 83 L.Ed. 1263. See Cover v. Schwartz, 2 Cir., 133 F.2d 541, 545; Western States Mach. Co. v. S. S. Hepworth Co., 2 Cir., 152 F.2d 79, 81. Without such a record on appeal, there is no way for an appellate court to know, in patent cases where the complaint has been dismissed solely for failure to prove infringement, what has been done, if anything, to determine whether the patent should be held invalid m whole or in part. Unless in such cases the record shows that, or can be required to show it, the approved practice, except in the comparatively rare instances where the patent in suit is obviously invalid, will be what the trial judges choose to make it and perhaps that is what the Supreme Court means to let it be. But if appellate courts are to have any effective supervision of the better practice, records on appeal must provide the basis for that. This record does so and accords with what seems to be needed for such supervision. Of course in those comparatively rare cases where the patent in suit is clearly invalid, and a trial court has failed so to hold, an appellate court may do so without any remand for findings for, by hypothesis, the record is already adeqaute to support such a decision.
But, where invalidity was a substantial issue, and the complaint was dismissed for non-infringement without findings on the question of validity in compliance with Rule 52(a), Fed. Rules Civ. Proc. 28 U.S.C.A., on appeal the judgment has been vacated and the cause remanded for such findings. Helbush v. Finkle, 9 Cir., 170 F.2d 41. I take that to mean that where the course followed below is not taken, in cases where validity presents a substantial question, it may be required in order that invalid claims be not left as a threat longer than necessary. But-1 do not understand that, on appeal by a plaintiff from a judgment dismissing a complaint solely on the ground of non-infringement, an appellate court need necessarily review the trial court’s conclusion, not carried into the judgment, that the claims are valid, before it can, in the absence of error as to the infringement issue, affirm the judgment. It has long been the practice to treat non-infringement and invalidity as sufficient and alternative grounds for dismissing the complaint in a patent infringement suit. See Coulter v. Eagle & Phenix Mills, 5 Cir., 35 F.2d 268, certiorari denied, 281 U.S. 758, 50 S.Ct. 409, 74 L.Ed. 1167. Cf. Altvater v. Freeman, 319 U.S. 359, 63 S.Ct. 1115, 87 L.Ed. 1450. Lest a disagreement within the court as presently constituted *582create unnecessary confusion, two of its judges think that what was recently said by L. Hand, C. J., in Harries v. Air King Products Co., 2 Cir., 183 F.2d 158, 161, 162, 163 should be emphasized by repetition:
“Since, as will appear, the defendant has not infringed the -claims, limited as they must be, the question arises whether we are compelled to review Judge Galston’s conclusion in favor of their validity. In what cases a court may dispose of a patent infringement action upon the issue of non-infringement, recent decisions leave in some doubt, we must own. In Electrical Fittings Corp. v. Thomas & Betts Co., 2 Cir., 100 F.2d 403, we held that, after deciding that a defendant did not infringe a claim, we need not pass upon a finding of the district court that it was valid. This we held because the finding had not been necessary to the judgment and for that reason would not be an estoppel, and would not therefore prejudice the defendant. The Supreme Court did not differ with us in thinking that the finding was immaterial, but nevertheless it directed us to strike it from the decree.3 The rationale of that decision was that the defendant was entitled to have it out because, although it was not an estoppel, it might create some presumptive prejudice against him. It is to be noted that the -court -did not suggest that we were bound to review the finding, for that would have been inconsistent with its mere deletion. The case is therefore clearly a holding that it is not in all cases necessary to decide the issue of validity. In Cover v. Schwartz, 2 Cir., 133 F.2d 541, the district court had held that the claim was neither valid, nor infringed, and we dismissed the appeal because the patentee did not question the holding of non-infringement. We said that the unchallenged holding that the defendant had not infringed made the case moot and ended our jurisdiction. That decision the Supreme Court cited with approval in Altvater v. Freeman,4 saying that ‘to hold a patent valid if it is not infringed is to decide a hypothetical case,’ relying on Electrical Fittings Co. v. Thomas & Betts, supra.5 Unless there is some difference between a finding of invalidity and a finding of validity, Cover v. Schwartz should have ended with a direction to strike out the 'holding of invalidity, and perhaps the reason why we did not do so was that a counterclaim remained to be tried.
“So the law stood when Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 S.Ct. 1143, 89 L.Ed. 1644, was decided. There the district court had held that the patent was invalid and not infringed, and we had held it valid and infringed. This the Supreme Court reversed, holding the patent invalid, but not passing on the issue of infringement, which have of course become moot upon the finding of invalidity. However, it went out of its way to say, 325 U.S. at page 330, 65 S.Ct. at page 1145: ‘There has been a tendency among the lower federal courts in infringement suits to dispose of them where possible on the ground of non-infringement without going into the question of validity of the patent’; then, after citing Cover v. Schwartz with apparent approval, it added: ‘the District Court in this case followed what will usually be the better practice by inquiring fully into the validity of this patent.’ One court has read this as a direction always to decide the issue of validity6 and perhaps it meant to go so far. However, if it did, it is hard to see how that was in accord ' with Electrical Fittings Co. v. Thomas & Betts, supra,7 with Altvater v. Freeman, supra,8 or with Cover v. Schwartz, supra,9 which proceed upon the implied premise that the issue of infringement may be disposed of before that of *583validity, since it is only in that event that the issue oí the validity can become ‘hypothetical,’ or ‘moot.’ The passage we have just quoted from Sinclair & Carroll Co. v. Interchemical Corp., supra,10 was certainly not put in the form of a peremptory direction, but rather of a cautionary admonition, to be followed when that is the more convenient course; and it is thus that Woodbury, J., construed it in Grant Paper Box Co. v. Russell Box Co.11 We are disposed so to understand it in the case at bar.
“There are good reasons for allowing some latitude of choice. A decision resting upon non-infringement is generally much more secure than one on invalidity, at least when the question is whether there is a patentable invention. That issue is as fugitive, inpalpable, wayward, and vague a phantom as exists in the whole paraphernalia of legal concepts. It involves, or it should involve, as complete a reconstruction of the art that preceded it as is possible. The test of invention is the orginality of the discovery, and discovery depends upon the mental act of conceiving the new combination for substantially every invention is only a combination. Nothing is more illusory, as nothing is more common, than to assume that this can be measured objectively by the magnitude of the physical readjustments required. Courts never tire, or at least in earlier times they never did, of expatiating upon the freshness of insight which observes a little, but fruitful, change which had theretofore escaped detection by those engaged in the field. When all is said, we are called upon imaginatively to project this act of discovery against a hypostatized average practitioner, acquainted with all that has been published and all that has been publicly sold. If there be an issue more troublesome, or more apt for litigation than this, we are not aware of it. The defence for always deciding it first, is that, if the claim be invalid, it should not be allowed to stand as a ‘scarecrow’; and that is quite true, granted the premise. Indeed, the same notion lies back of the disclaimer statute. But it must not be forgotten that the decision of a single court, whether district, or court of appeals, does not settle the question. It is the usual, if not universal, custom of practitioners if the stake is enough, not to rest content with a single decision of invalidity, but to seek another forum, as indeed the disclaimer statute permits.12 A declaration of invalidity may therefore prove an ignis fatuus, as fictitious a security to those who wish to infringe the claim, as a declaration of validity may be a fictitious menace. We hold that it is open to a court to proceed as is most convenient, subject to the exception that, though the defendant has not infringed, claims may be so evidently invalid that the court should so declare.”
The differences to which I have already referred as crucial on the question of infringement are those operations which were claimed as a part of the patented method, mz., the steps of carrying “an internally strained wire” into a “hollow body” and there depositing it “in a curled condition and as uniformly as possible within the, hollow by the recurrent flow of the gas therein.” I have designated them as crucial because a brief reference to the prior art will show that those steps are what Korver disclosed which was new if anything was. That it was already old to use a contained stream of gas to fill a holder with light material in strands is shown by the Schur patent, No. 1,915,451, which used compressed air to fill a receptacle with weak fiber strands carried into it by the air flowing within a tube. But this is as much as Korver might have learned from Schur, since the latter wanted the filler to be arranged within his container for easy withdrawal, and it had no internal strains, either inherent or imparted to it, to make it curl in the container and become a tangled mass held in place by its own elasticity against the walls. Nor was there what Korver calls his recurrent flow of *584gas. No other prior patent narrows the Korver claims more than Schur, and none, therefore, need be mentioned to demonstrate that unless the accused process does those things which distinguish the Korver process there is no infringement. That question depends, as always, upon whether, when the claims are interpreted so as to cover what is patentably new in the light of the specifications and of the prior art, the accused method does substantially the same thing in substantially the same way. Similarity, or even identity, of result will not alone suffice. Swan Carburetor Co. v. Chrysler Corporation, 6 Cir., 130 F.2d 393. Due regard must be had for what is known as the doctrine of equivalents to the end that minor omissions or minor changes will not serve to exonerate one who actually copies, and thus does appropriate, the gist of a patent. Cf. Graver Tank & Mfg. Co. v. Linde Air Products Co., 339 U.S. 605, 70 S.Ct. 854, 94 L.Ed. 1097; Royal Typewriter Co. v. Remington-Rand, Inc., 2 Cir., 168 F.2d 691. But when, as here, the accused process does not embrace those steps which distinguish the patented one from the prior art it does not infringe. Dixie-Vortex Co. v. Paper Container Mfg. Co., 7 Cir., 130 F.2d 569, 579, certiorari denied, 317 U.S. 686, 63 S.Ct. 260, 87 L.Ed. 550; Moto-Mower Co. v. E. C. Stearns & Co., 2 Cir., 126 F.2d 854.
The Product Patent
The patent, No. 2,162,847, for a “Flash Lamp” was granted to C. Korver June 20, 1939. His original application was embraced in that of the process patent already considered and was filed April 26, 1935. This application was divided from that on July 16, 1936, and it is conceded that the date to be accorded his invention is May 18, 1934, when an application for the same invention was filed in Germany.13
What this flash lamp is, what it does, and how it does it has already been largely though not entirely, told in dealing with the process patent. The better a photo-flash lamp is, the more nearly will it supply the right amount of actinic light at the right time for the camera with which the picture is taken to operate at its maximum efficiency. If the actinic light is- produced in synchronism with the shutter movement of the camera, allowing the peak light to affect the film, the best results will follow. But as is so often true, the problem is more easily stated than solved. I shall confine what I now say to the production of actinic light in a closed container like the patented and accused -lamps in suit. They produce it by burning a metal — aluminum alone or alloyed with some other substance such as magnesium — in oxygen under greater than normal atmospheric pressure. When combustion starts, the intensity of the light increases rapidly to its peak and then decreases to extinction. The speed with which the peak is attained increases, within limits not here important, as the metal burned is made finer (just as a fire of small pieces of wood will flash into flame more quickly than like wood in larger pieces) and it is more nearly uniformly distributed throughout the container, so that all portions of the metal are surrounded by nearly equal amounts of oxygen. This construction results in a comparatively even rate of combustion, thereby giving a longer maximum output of actinic light. For photographing rapidly moving subjects, the camera shutter should, preferably, be open within this period of maximum output for the time required to sensitize the film and it is obvious that the longer the peak of the flash the easier it is to have the shutter opened within some part of that period. If the duration of the peak and the shutter time were equal the synchronization would have to be perfect for best results but if, for instance, the peak duration substantially exceeds the required shutter time there is a comparatively large tolerance for errors in synchronization, because during the peak any time the shutter opened and closed would do as well as any other. Furthermore, when flash lamps are, like these, ignited by electrically generated heat in contact with the metal, the contact time, i. e., the time in which a given amount of electricity will create heat sufficient for ignition, is shortened by using finer filling. *585Thus lamps constructed in accordance with the product patent have characteristics which give them decided advantages.
As the trial court found from ample evidence: “The lamps manufactured by Wabash embodying the Korver patented product are cheaper, smaller, more uniform and more efficient than any photo-flash lamps previously made. They have a light curve which differs from that of the foil lamp in having a lower, broader peak, more like a plateau, so that the difficult problem of synchronization with the camera shutter is largely avoided.”
The only lamp which, before the patented lamp, was commercially successful was the foil filled one of Ostermeier, which the Korver lamp pushed off the market. That lamp has already been described, and with its crumpled thin foil, is no anticipation. The foil filler did not burn as readily as the wire one and this comparative inefficiency retarded its production of usable actinic light. Van Liempt’s Patent No. 2,037,101 teaches some of the advantages of using wire in place of foil as a filler, but his wire was not uniformly distributed throughout the bulb nor held elastically in place within it. Instead it was wound into a clew and was supported by, or from, the stem which bore the igniter, rather than by the walls. He was primarily concerned with a wire made from aluminum and magnesium in the proportions disclosed. Crowley, in two British patents, Nos. 403,427 and 403,638, mentions metallic wool, among other filling materials, as suitable for a flash lamp, but he comes no cl'ciser to showing the Korver lamp. Leijdens filed an application on March 15, 1935, which was the same as his application filed in Germany on March 26, 1934, for a flash lamp and was granted a patent, No. 2,091,601, on August 31, 1937. While it is doubtful whether it is prior art, assuming, without, deciding, that it is, the application discloses nothing which anticipates. Leijdens described and patented a device for igniting the filler by means of a “spontaneous reaction” which dispensed with the use of electricity and the consequent need for an electrical supply source. His drawings, which are alone relied on, show bulbs filled with undulating wire in a random course and in a more or less tangled, perhaps curled, condition. Although the wire seems at spots to touch the walls, the contact is not enough to provide appreciable support. Moreover, any doubt as to what does support his filler there might otherwise remain is resolved by the description of a typical drawing, Fig. 1, in the specifications as follows: “Within the bulb and supported by the stem 50 is a combustible material 4 shown as a clew of drawn magnesium or magnesium alloy wire.” Thus it appears that the support for the filler is the stem, not the walls, and that the filler is a clew of wire, quite unlike the Korver filler. Nothing else in the prior art has been called to our attention which is sufficiently near anticipation to require discussion.
Korver was the first to create a flash lamp with a filler uniformly distributed and held in place within the bulb so that the output of actinic light was more easily co-ordinated with the camera and more useful for photographic purposes. His lamp was cheaper to manufacture and less fragile than previous bulbs and it drove them off the market. It is true that the enormous commercial success of the lamp may justly be attributed in considerable part to other factors, like a safe increase in the oxygen pressure which allowed a decrease in the size of the bulbs without a lessening in the actinic light available for use. But I need make no attempt to apportion the cause of its success for that is the make-weight which may tip the scales when the fact of invention is otherwise in doubt. Cf. Jungerson v. Ostby & Barton Co., 335 U.S. 560, 567, 69 S.Ct. 269, 93 L.Ed. 235; Goodyear Tire & Rubber Co. v. Ray-O-Vac Co., 321 U.S. 275, 279, 64 S.Ct. 593, 88 L.Ed. 74. I think that it has here been otherwise proved.
Of the three claims of the patent, all of which were held valid, No. 2 is typical and reads: “2. A flash-lamp comprising a container of actinic light-transmitting material having an active portion, a mass of thin undulated wire disposed within' said active portion so as to be elastically supported *586from the wall thereof, and a gas which upon ignition enters into an actinic reaction with said wire, said wire being arranged in a serpentine course so as to be in substantially uniform spacial distribution.”
It was shown that when the defendant’s Ostermeier flash lamp was unable to meet successfully the competition of the patented lamp, the defendant cast about for something that would, and eventually turned up the accused lamps which, being able to do so, have been sold over the succeeding years in about the same quantity as the patented ones. These lamps have already been sufficiently described. It is argued that they do not infringe because the filler is shredded aluminum foil instead of “wire”; because the filler is not “undulated”; and because it is not kept in place in the bulb by its own pressure elastically on the walls.
There is evidence to the effect that the word “wire” is often used to denote a drawn filament. That of course means a round wire, something which the accused filler is not. But there is other evidence which well shows that the term wire is understood to embrace much more than that and to include materials not the result of any drawing operation but of other operations, including shearing, and that “square wire” and that of other shapes is known. That the claims used “wire” in this broad sense to denote material usable as the filler rather than to denote any particular manner of making such filler seems plain enough when it is remembered that nothing was required of it after it was in place in the bulb but to remain there and to burn when ignited. The evidence shows that the accused filler is made of shreds which, though not continuous, are each longer than the diameter of the bulb in which used so that no piece can remain straight for its full length when in position. These pieces are there deformed, intertwined and enmeshed with each other as the result of the force exerted by- the process which puts them there. And they so press upon each other and upon the wall of the bulb that they retain the nearly uniform distribution imparted by the fluffing operation having enough inherent elasticity to do so. Indeed there was substantial evidence to support the following finding of the trial court. “The accused photoflash lamps are characterized by the undulating and serpentine course of the shredded material which forms a tangled mass of crumpled .shreds bent in every conceivable direction at non-uniform intervals. The individual shreds are fine, fragile wires. The wire filling. material of the accused lamps is substantially identical with that described in the Korver patents, even though it is in the form of 8-inch shreds rather than continuous. The mass of shreds is so light (generally less than a tenth of a gram) that the loops and tips in contact with the glass wall of the bulb are adequate to support the filling elastically and hold it in place, just as taught in the Korver patents. In every particular referred to in the claims, the structure of the accused lamps is the same as or the substantially equivalent of that described and claimed in the Korver product patent.”
What the defendant 'has done is but to substitute for the continuous wire of Kor-ver a practically perfect equivalent — shreds sufficiently long to accomplish substantially what Korver’s wire accomplishes and in substantially the same way. The interchangeability of these two substances or “wires,” once Korver’s disclosures were made available to those skilled in the art, was seemingly obvious. The doctrine of equivalents, long recognized in patent law and lately given effect in Graver Tank & Mfg. Co. v. Linde Air Products Co., supra, does not permit such close copying of the patented device as was here done.
I am unable to agree with my brothers that the product patent is invalid and would affirm the judgment in respect to both patents.

. The wire filler of a photo-flash bulb must, of course, be made of metal which will burn as desired, like aluminum or an alloy of it and magnesium.

. Usually .001 of an inch, the same as the thickness of the foil, so that the strip is roughly square in cross section.

. 307 U.S. 241, 59 S.Ct. 860, 83 L.Ed. 1263.

. 319 U.S. 359, 363, 63 S.Ct. 1115, 1117, 87 L.Ed. 1450.

. 307 U.S. 241, 59 S.Ct. 860, 83 L.Ed. 1263.

. Pennington Engineering Co. v. Spicer Mfg. Co., 6 Cir., 165 F.2d 59, 61.

. 307 U.S. 241, 59 S.Ct. 860, 83 L.Ed. 1263.

. 319 U.S. 359, 63 S.Ct. 1115, 87 L.Ed. 1450.

. 2 Cir., 133 F.2d 541.

. 325 U.S. 327, 65 S.Ct. 1143, 89 L.Ed. 1644.

. 1 Cir., 151 F.2d 886, 890.

. Triplett v. Lowell, 297 U.S. 638, 56 S.Ct. 645, 80 L.Ed. 949.

. R.S. § 4887, 35 U.S.C.A. § 32.