Full opinion text
STEEL, District Judge. Simmons, a patentee, and his licensee, Baldwin-Lima-Hamilton Corporation (hereinafter “Baldwin”) have sued The Budd Company (hereinafter “Budd”) and its wholly owned subsidiary, Tatnall Measuring Systems Company (hereinafter “Tatnall”), for infringement of Claims 1, 2, 3, 4, 5, 7, 8 and 9 of Patent No. 2,292,549 (hereinafter “Simmons patent”). The patent relates to a gage for measuring strain in materials. Baldwin has marketed “bonded wire strain gages” under the Simmons patent since 1940. Without license from plaintiffs, Tatnall has manufactured, used and sold “foil type” strain gages and Budd has used “foil type” strain gages manufactured by Tatnall. The ■“foil gages”, plaintiffs charge, infringe the Simmons patent. In defense the defendants have pleaded (a) noninfringement; (b) invalidity because of (i) anticipation, (ii) lack of invention and obviousness, (iii) inadequacy of patent description, and (iv) inclusion of new matter in amendment to application; and. (c) unclean hands because of (i) fraud on the Patent Office, and (ii) patent misuse. Jurisdiction exists under 28 U.S.C. § 1338(a). Subject Matter of Simmons Patent The load or force which is applied to a body is known as “stress”. It may be expressed in terms of pounds per square inch. When a body is subjected to stress, it is deformed to some extent. The deformation is known as “strain”. It may be expressed in terms of inches of strain per inch of length. In any material used for engineering purposes, the stress must be kept within safe limits to prevent failure. Well-known and determinable relationships exist between stress and strain in engineering materials. Where the strain in a material is known at a given point, the stress at that point can be ascertained. The purpose of the Simmons gage is to measure strain. The gage employs the principle discovered by Lord Kelvin more than a century ago that the electrical resistance of materials which are electrically conductive varies with the strain thereof. If the material is stretched, its resistance will increase; if it is compressed, its resistance will decrease. This property is referred to in the Simmons patent as “electrical strain sensitivity”. Claim 5 contains three elements: (i) a test body whose strain is to be measured, (ii) a continuous metallic filament of solid electrical conducting material whose electrical resistance varies in accordance with changes in strain in the filament, and (iii) a means for adhesively bonding the filament in an untaut condition throughout its effective length to the body to be tested so that the filament forms a completely unitary part of the test body. When a filament described by Simmons is bonded to a test body as Simmons has directed, any deformation of the test body will cause a corresponding deformation in the filament (for instance, a lengthening of the test body will cause a commensurate lengthening of the filament) and the electrical resistance of the filament will vary as deformation changes occur. By an appropriate electrical circuit (not subject to the Simmons patent) the variance in the electrical resistance of the filament can be recorded. By comparing such resistance changes with the predetermined electrical strain sensitivity of the filament, the strain in the test body can be ascertained. Infringement 35 U.S.C. § 271(a) defines infringement as the unauthorized making, using or selling of a “patented invention”. The critical question, therefore, is what the Simmons patented invention is, and whether the foil gages manufactured by Tatnall embody it. The sketches below have been agreed upon by counsel as magnified versions of the Baldwin gage (wire type) and the Tatnall gage: In the Simmons bonded wire gage the electrical current flows from one end of the wire to the other, and the entire length of the wire, wound back and forth, is the gage. In the foil gage of defendants the current flows from one lead connection tab through the first straight length of foil, then across the enlarged connecting portion of foil, then down through the next straight length of foil, then across the next enlarged connecting portion of foil, and so on, to the other lead connection tab. As in the Simmons gage, the foil gage is bonded to the specimen to be tested, thereby becoming a slave, as it were, of the test body, and deforming precisely as the test body deforms. With the occurrence of deformations in the foil measurable variations take place in the electrical resistance of the foil. The Simmons wire strain gage operates on this same principle. Defendants contend that the invention of Simmons is limited to a “filament” in the form of a wire, that the foil of defendants’ gage is neither a wire nor a filament, and that therefore the foil gage does not embody Simmons’ invention. Plaintiffs assert that Simmons did not limit his invention to a filament which was a wire but intended filament to have a connotation sufficiently broad to comprehend the foil conducting elements of the defendants’ gage. Claim 5 is not in words restricted to a filament in the form of a wire. But the claims of a patent need not be read in a vacuum. For purposes of determining whether an accused device is an infringement, the claims of a patent are to be interpreted not only in the light of the specification but also with reference to the file wrapper history. Mas v. Owens-Illinois Glass Co., D.C.D.N.J. 1954, 122 F.Supp. 582, 583; affirmed, 3 Cir., 1955, 222 F.2d 889; certiorari denied 350 U.S. 1016, 76 S.Ct. 661, 100 L.Ed. 875; rehearing denied, 1946, 351 U.S. 943, 76 S.Ct. 838, 100 L.Ed. 1470. Here, both the specifications and the representations which Simmons made to the Patent Office during the patent prosecution establish that the filament which Simmons claimed as an element of his invention was a filament in the form of a wire. Thus, Simmons says in his specification, “To determine the strain * * * I employ my improved strain sensitive electrical means consisting of a filament of very fine metallic wire”. At other places in the specification the word “filament” is used in conjunction with “wire”; as for example, “wire filament” and “wire forming a filament” . The file wrapper discloses that Simmons used the words “wire filament” at least thirteen times and the word “wire” no less than thirty-eight times. Nowhere did Simmons define the word “filament” in any other way. At one point Simmons said, “ * * * applicant’s filament is a continuously solid metallic wire element * * * ”. In distinguishing the Lorig patent which the Patent Office had cited as an anticipation, Simmons pointed out that Lorig had no thought of using “a strain sensitive filament formed of a continuously solid metallic wire * * * ” , thereby inferentially indicating that the' Simmons patent did call for a “metallic wire”. That Simmons limited his electrical strain sensitive element to “fine metallic wire” is conclusively settled by the affidavit which Simmons filed in the Patent Office on August 19, 1941. There Simmons described his “invention” as follows: “A continuously solid fine metallic wire was bonded throughout its effective length to a member subject to strain and this wire was connected to an electrical circuit whereby a change of strain in the wire was accompanied by a predetermined change of electrical resist-anee of the wire. The change in electrical resistance was measured by the electrical circuit, thereby indicating the amount of strain.” If “filament” in the Simmons patent is construed to mean wire, then the foil elements of defendants’ gages are outside the literal terms of the claims. And even though filament is given some latitude of meaning beyond that of wire, still in its primary sense, it means “a thread or a slender, thread-like object * * * ”. , Webster’s New International Unabridged Dictionary. Dimensionally the foil elements of defendants’ gage are completely lacking in the “thread-like” characteristic of a filament. In defendants’ 130-1 gage, the thickness of the foil is approximately .000150 inches and the width of straight lengths is .0096 inches, giving a ratio of width to thickness of approximately 64 to 1. In defendants’ 141 gage, the thickness of the foil is the same and the width is .0062, giving a ratio of width to thickness of approximately 41 to 1. The foil elements can be more accurately described as ribbons or strips than filaments. Accordingly, defendants have not been guilty of a literal infringement of Simmons’ patent. In spite of this fact, a comparison of defendants’ foil gage with plaintiffs’ wire gage discloses that the distinctions between the two are colorable only. Uncontroverted testimony by plaintiffs’ expert, Dr. Ruge, as well as a courtroom demonstration which stands unassailed, establish that the two devices do the same work in substantially the same way and accomplish the same result. The devices in the eyes of the law are therefore the same under the doctrine of equivalents which had its origin in Winans v. Denmead, 1854, 15 How. (56 U.S.) 329, 330, 342-343, 14 L.Ed. 717 more than a century ago. The fact that the two gages may be different in form or shape is not important. Nor is it significant whether the Simmons invention is primary or secondary in character. Even a patentee of a secondary invention consisting of a combination of old ingredients which will produce a new and useful result is entitled to claim the benefits of the equivalency doctrine since its essence is the prevention of a fraud on a patent. Graver Tank & Mfg. Co. v. Linde Air Products Co., 1950, 339 U.S. 605, 607-608, 70 S.Ct. 854, 94 L.Ed. 1097. In Haskell Golf Ball Co. v. Perfect Golf Ball Co., D.C.S.D.N.Y. 1906, 143 F. 128 it was held that under the doctrine of equivalents a golf ball made of a thin and highly elastic “rubber band” infringed a golf ball patent which claimed as an element a “rubber thread” winding, because the band “serves every purpose of the thread” and “is its equivalent in every respect. It answers the same purpose and performs the same function.” At page 131. These words might well have been written with respect to the foil element of defendants’ gage in its relationship to the filament of the Simmons patent. Defendants assert that the foil' gage has definite advantages over the Simmons gage in that the enlarged connecting portions in the foil gage between the straight lengths have a width several times greater than the width of each straight length, and this gives the gage a greater bonding area and reduces the adverse effect of the sections transverse to the applied strain. So far as the record reveals, in the Simmons gage neither the bonding nor the transverse sections of the wire created a problem which required solution. In any event, an infringement cannot be avoided by making an improvement on the particular form of a patented device even where, unlike the situation at bar, a patent has issued on the so-called improvement. Temco Electric Motor Company v. Apco Mfg. Co., 1928, 275 U.S. 319, 328, 48 S.Ct. 170, 72 L.Ed. 298; Otto Coking Co., Inc., v. Hoppers Co., 3 Cir., 1919, 258 F. 122, 135; Balaban v. Polyfoto Corp., D.C.Del., 47 F.Supp. 472, 480. In determining whether an accused device constitutes an infringement a court must first look into the art to find what the real merit of the alleged invention is and whether it has advanced the art substantially. If it has done so, then a court should be liberal in construing the patent and in finding infringements in the use of equivalents to the end that the inventor may secure the reward which he deserves. Eibel Process Co. v. Minnesota & Ontario Paper Co., 1923, 261 U.S. 45, 63, 43 S.Ct. 322, 67 L.Ed. 523. This principle is apposite. The record establishes overwhelmingly that the merit of the Simmons gage was so compelling that, once it was accepted, it virtually supplanted all types of prior art gages. It is clear, therefore, that Tatnall has infringed the Simmons patent by making, using and selling foil gages which embody the Simmons invention, and that Budd has infringed the Simmons patent by using foil gages which it has purchased from Tatnall. Validity (a) Anticipation Defendants contend that a paper published by St. Lindeck in Germany in Í908 constitutes an anticipation of Simmons which renders his patent invalid. 35 U.S.C. §§ 102, 282. St. Lindeck was a scientist with Physikalish-Technische Reiehsanstalt (hereinafter “Reichsan-stalt”), an organization corresponding to the United States Bureau of Standards. In 1908 he wrote an article, “On the Influence of Air Humidity on Electric Resistances”. This was written because of two earlier papers by Rosa and Dorsey and by Rosa and Babcock, employees in the United States Bureau of Standards. The Rosa and Dorsey paper, according to St. Lindeck, indicated that Rosa and Dorsey had checked the “resistances of Wolff’s resistance boxes” which were an assemblage of highly precise wire coils and connections manufactured by Otto Wolff of Berlin for use as comparison resistors in electrical measurements. According to St. Lindeck, Rosa and Dorsey had found that the resistances at equal temperatures during the summer had higher values than in the winter and that the increase in the spring and the decrease in the fall took place very gradually. This phenomenon was the subject of later study by Rosa and Babcock whose conclusions were thus summarized by St. Lindeck: “It was found that the hygroscop-icity of the shellac that was used in the manufacture of the resistances was the cause of the phenomenon. As is known, the wire which is insulated with silk in the resistances of the Reiehsanstalt is wound on a metal tube; for obtaining a good insulation, the tube was originally coated with a shellac solution only, before winding the wire; later it was thought advisable, on account of the above mentioned reason, bek-leben [to adhere] a piece of shellacked silk fabric on the spule [spool]. After winding on the wire, the whole spule [coil] is again lacquered and is then dried for a considerable time, about 10 hours at 140° C. for the purpose of aging. “According to Rosa and Babcock, the periodic changes of resistance are so explained that with increasing relative air-humidity the shellac, particularly the lacquer lying between the wire and metal tube swells; the diameter of the base on which the wire was wound increases and the resistance wire is stretched elastically on account of the forces produced thereby, so that the resistance is increased; with decreasing humidity the shellac, on its part, gives off moisture and shrinks; the pressure on the wire is decreased and the resistance is again reduced. Because during the entire year the relative humidity is lowest in winter, particularly in heated rooms, while in summer approximately the high atmospheric humidity prevails in laboratories, the phenomenon is perfectly understandable. * * * ” (Emphasis by St. Lindeck.) Thereafter the St. Lindeck paper states that upon the suggestion of a Mr. Warburg he (St. Lindeck) “confirmed by direct experiment” the explanation given by Rosa and Babcock of the effect of humidity changes upon resistance. St. Lindeck described his experiments as follows: “« * * ipkg correctness of the above given explanation was, upon a suggestion of Mr. Warburg, confirmed by a direct experiment. A resistance Spule [coil] was so arranged that by means of a pressure pump a pressure up to 60 atmospheres could be exerted from the inside on the brass tube and thereby on the wire winding; it was apparent that the resistance changes were exactly proportional to the pressure and that the wire followed the changes in diameter of the tube with perfect elasticity. With a wall thickness of the brass tube of 0.5 mm. (with 2 cm. diameter) a pressure change of one atmosphere produced a resistance change of 7 x 10-6. Perhaps a method for measuring high pressure may be based hereon.” (Emphasis by St. Lindeck.) The St. Lindeck article, considered in its entirety, defendants argue, teaches one skilled in the art how to make and use a bonded wire strain gage. It is to be noted, however, that the experiment, as described by St. Lindeck, does not say that the wire was bonded or adhered to the brass tube around which it was wrapped. On the contrary, St. Lindeck’s description of the experiment at least suggests that the wire was not bonded. St. Lindeck says that pressure was exerted “from the inside on the brass tube and thereby on the wire winding; * Read literally, St. Lindeck is saying that the pressure imparted internally to the brass tube was transmitted by the brass tube directly to the wire winding. St. Lindeck does not mention shellac (the bonding means which defendants say that St. Lindeck used) as an intervening agency of transmission. This omission is especially significant because when St. Lindeck referred to the work of Rosa and Babcock he pointed to their conclusion that the diameter of the base on which the wire was wound changed because of the swelling of the “lacquer” and the shrinking of the “shellac”. Yet, in describing his own experiment St. Lindeck simply stated that the air pressure was exerted “from the inside of the brass tube and thereby on the wire winding” without any reference to the presence of “lacquer” or “shellac”. Notwithstanding this affirmative evidence that the wires were not bonded to the tube in St. Lindeck’s experiment, defendants assert that the fact that the wires were bonded appears from other parts of the St. Lindeck paper. This is based upon the assumption that St. Lin-deck performed his experiment on a coil taken from a “Wolff resistance box” (or “Wolff box”) and that the wires on these coils were bonded to the brass tube by the use of shellac in accordance with the manufacturing techniques of the Reichstanstalt described by St. Lindeck (supra, 169 F.Supp. at page 9). Although the evidence substantiates that the wires of the “Wolff resistance box” were bonded to the brass tube, the record is far from clear that St. Lindeck in fact used a coil from a Wolff box. Defendants’ assertion to the contrary is not based upon what St. Lindeck said, but is drawn from inferences which they and their expert, Mr. Roberts, derive from the description of the St. Lindeck experiment and from other parts of his paper. Thus, defendants point out that St. Lindeck shows that the investigation of Rosa and Babcock was concerned with coils from a Wolff box which had a diameter of two centimeters, that St. Lin-deck used a two-centimeter coil in his experiment, that St. Lindeck conducted a “direct experiment” to confirm the Rosa and Babcock explanation of the humidity resistance phenomenon, and that St. Lindeck found in his experiment that the resistance changes were exactly proportional to the pressure and that the wire followed the changes in diameter of the tube with perfect elasticity. From these facts defendants assert that the conclusion is certain that St. Lindeck’s experiment involved the use of a coil from a Wolff box. Defendants attribute unwarranted significance to the statement that St. Lin-deck corroborated the Rosa and Babcock observation by “direct experiment”. This does not necessarily mean that Lin-deck used a coil from a Wolff box simply because Rosa and Babcock did. St. Lin-deck was not interested in studying a Wolff coil to see whether shellac in its absorption of moisture caused the diameter of the coil to increase. Had this been his objective, it would have been necessary to subject a Wolff coil to humidity variations (either actual or simulated) and then to have measured the changes in diameter of the coil to see whether he could correlate the diameter changes with the humidity changes. What St. Lindeck set out to do was to determine whether, if a change in the diameter of the coil had been occasioned by the absorption of moisture by the shellac as Rosa and Babcock had postulated, such a change in the diameter would produce changes in the electrical resistance of the magnitude indicated by Rosa and Babcock. The utilization of a Wolff box coil was not needed for this purpose. By introducing pressure into any tube, St. Lindeck could measure the varying changes of resistance occasioned by the expansion of the tube. Moreover, the tube used in a Wolff box coil was open at each end. If St. Lindeck had desired to experiment on a Wolff box coil, it would have been necessary to modify the coil by sealing off one end with sufficient firmness to withstand the pressure of several hundred pounds occasioned by the pressure of 60 atmospheres and by attaching to the other end a pressure mechanism of some kind. Furthermore, the fitting which was brazed into one end of the tube used in the Wolff box coil for purposes of attaching it to the Wolff box would probably have had to be removed. In the view of Dr. Ruge, at least, these modifications would have almost certainly destroyed the precision of the coil. Defendants point out that St. Lindeck in describing his experiment said that “the resistant changes were exactly proportional to the pressure and that the wire followed the changes in diameter of the tube with perfect elasticity”. Upon the basis of the testimony of Mr. Roberts, defendants’ expert, it is argued that if the wire had not been bonded to the tube, the tube and the wire would not have acted as a unit, there would have been minor movements between the tube and the wire, and the wire would not have acted with perfect elasticity. On the other hand, Dr. Ruge, plaintiffs’ expert, testified that since in the resistance applications with which St. Lindeck was working the wire was not stretched beyond its elastic limit, the elastic properties of the wire would compel the wire to follow changes in circumference of the tube upon its expansion and contraction regardless of whether the wire was bonded. This view is substantiated by Rundell Patent No. 2,663,781 which deals with electrical pressure gages employing strain-responsive wire elements. The patent recognizes that when wire is wound onto a hollow cylindrical body into which fluid pressure is introduced, the wire winding will react to changes in diameter of the cylindrical body with resultant variations in the electrical resistance of the wire, and that the imposition of tension in the winding of the wire “eliminates the necessity for bonding the filament throughout its effective length to the surface on which it is wound”. While the patent does not say that the wire reacts to pressure changes with perfect elasticity, this must have been substantially so, for otherwise the utility of the device as a pressure gage would be impaired. Defendants argue that the presumption of validity of the Simmons patent is not operative against the Lin-deck publication, since St. Lindeck was not cited against Simmons in the Patent Office. Conceding that this is so, I am unable to find within the four corners of St. Lindeck that he conducted his experiment with the coils from a Wolff resistance box; and if he did not, the premise that he used a bonded wire vanishes. The conclusion that St. Lindeck did use coils from a Wolff resistance box rests at best upon inferences, deductions, and explanations of plaintiffs’ expert. All of these I find inconclusive as against the affirmative evidence in the St. Lin-deck paper that Wolff box coils were not used by St. Lindeck in his experiment, that for practical reasons it is unlikely that St. Lindeck would have attempted to modify a Wolff coil to the extent necessary for his experiment, and that the use of the coil from a Wolff resistance box was not needed to obtain the confirmatory data which St. Lindeck was seeking. In any event, inferences as distinct from disclosures cannot be accepted as a basis for anticipation. Skelly Oil Co. v. Universal Oil Products Co., 3 Cir., 1929, 31 F.2d 427, 431. While Skelly deals with an anticipating patent, the law of anticipation is the same regardless of whether a prior patent or publication is relied upon. Willamette-Hyster Co. v. Pacific Car & Foundry Co., 9 Cir., 1941, 122 F.2d 492, 497; Midland Flour Milling Co. v. Bobbitt, 8 Cir., 1934, 70 F.2d 416, 417. The fact that St. Lindeck was inadequate to teach persons skilled in the art how to make and use a bonded wire strain gage, is substantiated by the fact that although the article was published in Germany in 1908 no bonded resistance type strain gages had been developed in Germany prior to the end of the Second World War. With the multitude of demonstrated advantages of the bonded gag-es it is not likely that the Germans, under the pressure of wartime demand for strain measurement, would have failed to develop bonded gages if St. Lindeck taught how they could be made and used. Defendants likewise cite as an anticipation an article by P. H. Dike in Review of Scientific Instruments, Yol. 7, July 1936, pp. 278-287. This article relates generally to an investigation conducted on the effect of humidity on resistance elements by reason of its effect on the insulation covering the wires of such elements. In this investigation Dike made a number of experiments. These showed, among other things, that coils wound with silk-covered wire increased in resistance with increased humidity, that coils wound with cotton or linen decreased in resistance with increase in humidity, that coils with no textile covering did not change in resistance with change in humidity, and that strands of silk and of cotton or linen unwound from the wire increased and decreased in length, respectively, with changes in humidity. Dike then proceeded to explain the changes of resistance with humidity variations as follows: “With a silk covering a decrease In humidity causes a shortening and tightening of the covering. The spiral wrapping thus exerts an additional pressure on the wire, and at the same time, a longitudinal force, tending to shorten it and thus decrease its resistance, while an increase in resistance produces the contrary effect. With linen or cotton covered wire, which, as stated above decreases in length with increase in humidity, the effect should be just the opposite to that of silk, as has been observed.” Immediately thereafter Dike added: “It should be noted that, in order to make these changes in length of the covering material react upon the wire, it must adhere to the wire sufficiently to resist a longitudinal sliding of the insulation along the wire. If the wire with its covering is impregnated with shellac or other varnish the adherence between the wire and covering becomes stronger and the humidity effects on the resistance are somewhat increased, as is confirmed by our observations.” Upon the basis of these observations, and particularly the latter one, defendants assert that Dike taught that when a strain sensitive wire is bonded to a test body changes in strain of the test body are transmitted to the wire through the bonding medium with resulting changes in the resistance of the wire corresponding to the changes in the strains encountered by the test body. In the Dike article the test body, according to defendants, is the textile insulation around the wire. I fail to find any suggestion by Dike that strain may be measured by the use of bonded wire or otherwise. Dike’s interest was in the elimination of strain which occurred in the textile wrappings by virtue of the action of humidity thereon. The detection of this strain did not rest upon any observed variations in electrical resistance; On the contrary, it resulted from Dike’s observation of changes in length of the textile wrappings after the wrapping had been unwound. Nor can one glean from what Dike says that bonding is taught in any sense comparable to Simmons. Dike says that in order to make the changes in the length of the covering material react upon the wire, it must adhere to the wire “sufficiently” to resist a longitudinal sliding along the wire. This means that if the forces generated by changes in length of the wire wrapping as a result of humidification are to be imparted to the wire there must be some amount of adhesion of the wrapping to the wire. When Dike states that if the wire and covering are impregnated with shellac the adherence between the wire and covering becomes stronger and the humidity effects on the resistance are “somewhat increased”, he obviously means only that the shellac augments, in a matter of degree, the effect of the unshellacked winding. This statement falls far short of teaching what Simmons taught, namely to measure strain the wire should be bonded throughout its effective length to the test specimen so that the wire forms a completely unitary part of the specimen. But even if Dike can be read as stating that alterations in the resistance of the wire are to be explained by dimensional changes in the wrapping which are communicated to the wire because the wire and the wrapping constitute a unitary part of each other, still Dike does not anticipate Simmons. Dike’s observations related to the precision resistor art. Simmons’ discovery pertains to the strain gage art. The two are not analogous. Attempts to distort and magnify prior non-analogous art by way of anticipation have been condemned by the Courts. Alemite Mfg. Corporation v. Rogers Products Co., 3 Cir., 1930, 42 F.2d 648, 651. To ascertain whether two arts are analogous, heed must be given not merely to their physical differences but particularly to the differences in their problems and the means and methods of solving them. Radiator Specialty Co. v. Buhot, 3 Cir., 1930, 39 F.2d 373, 374; Wallace v. Mandel Bros., Inc., 7 Cir., 1947, 164 F.2d 861, 864. So tested it is plain that the precision resistor art with which Dike was concerned is not sufficiently related to the strain resistor art dealt with by Simmons to charge Simmons with knowledge of the Dike article. For Simmons to have applied the disclosures of Dike to advance the strain gage art in the manner which he did would in itself have been an inventive act. Compare General Electric Co. v. Hoskins Mfg. Co., 7 Cir., 1915, 224 F. 464, 467, 470; Yablick v. Protecto Safety Appliance Corp., 3 Cir., 1927, 21 F.2d 885; Akme Flue, Inc., v. Aluminite Flexible Flue Cap Co., 2 Cir., 1928, 27 F.2d 736. Dike was associated during his lifetime with Leeds & Northrop Company, an outstanding manufacturer of precision measuring instruments. Significantly, it never evolved a strain gage based upon Dike’s work. Presumably it was unable to discern in the Dike article what plaintiffs say it so clearly discloses. (b) Lack of Invention — Obviousness Unquestionably Simmons’’ bonded strain gage was new and useful. But to render a device patentable the additional element of invention is required. Thompson v. Boisselier, 1885, 114 U.S. 1, 11, 5 S.Ct. 1042, 29 L.Ed. 76; Cuno Engineering Corporation v. Automatic Devices Corp., 1941, 314 U.S. 84, 90, 62 S.Ct. 37, 86 L.Ed. 58. Invention cannot exist unless the subject matter of the patent discloses more ingenuity and skill than that possessed by an ordinary mechanic. Hotchkiss v. Greenwood, 1850, 11 How. (52 U.S.) 248, 267, 13 L.Ed. 683; Sinclair & Carroll Co. v. Interchemical Corp., 1944, 325 U.S. 327, 330, 65 S.Ct. 1143, 89 L.Ed. 1644. Invoking this principle, defendants assert that since the prior art disclosed a bonded carbon strain gage and an un-bonded wire gage, all that Simmons did was to take the obvious step of substituting wire for carbon and his patent is therefore invalid under 35 U.S.C. § 103. Simmons, who was participating as a graduate student in the Cal. Tech. Impact Research Project, was fully aware of the bonded carbon gages, and, since the Carlson unbonded wire gage was patented on April 7, 1936 and articles discussing the principle of that gage had been published by Eaton in 1931 and by Carlson in 1935, Simmons was chargeable with knowledge of the Carlson principle. Zephyr American Corporation v. Bates Mfg. Co., 3 Cir., 1942, 128 F.2d 380, 385. Defendants argue that the advantages of flexibility, relative stability and freedom from hysteresis and moisture and temperature effects, and capability for mass calibration, which are ■claimed by Simmons as advantages over the bonded carbon gages, are properties inherent in wire. Anyone with ordinary ■skill in the art, defendants say, would have recognized that the shortcomings of the bonded carbon gages and the unbonded wire gages could be overcome, and the advantages of each could be retained, by substituting the bonding of wire for the bonding of carbon since the properties of wire and the advantages of bonding were known. This argument, persuasive though it be, must be considered in the light of the experience of others who were attempting to solve the •strain measurement problem. The argument cannot withstand this test. For years the safety of propellers was a matter of the utmost concern to the aeronautical industry. As early as 1916 when propellers were constructed entirely of wood, vibratory stresses had been the primary cause of propeller failures. With the advent of metal propellers in 1936 the problem became even more criti-Realizing that propeller failures could be explained and avoided only by locating the causes of the vibrations and determining the amount of stress which the propeller assemblies could withstand, about 1930 Hamilton-Standard, a division of United Aircraft Corporation, embarked on an exhaustive program of research on vibratory stresses as they affected propellers. Efforts were concentrated on developing devices by which vibratory strains could be measured both in the shop and in flight, for it was realized that in the absence of quantitative assessment of the strains, prediction of safety was largely a matter of intuition. cal. Hamilton-Standard tried many types of strain measuring devices. Prior to the summer of 1936 it had experimented with an optical method, a “scratch” gage, an electro-magnetic system, and a piezoelectric system. Practical difficulties were encountered with all of these. Efforts were then focused on finding some sort of a resistance gage. In the spring of 1936 the Aquadag method suggested by Hull of General Electric was tried and abandoned. This involved the painting of colloidal graphite (carbon) electrically sensitive to strain to a member to be strained and passing an electric current through the strip. Thereby the variation in the strain of the specimen which was transformed to the colloidal graphite could be determined by the variance in the recorded electrical resistance of the colloidal graphite. Beginning in the summer of 1936, Hamilton-Standard tried successively a number of different types of bonded carbon resistance gages all of which utilized as the resistance element carbon sticks which were bonded to the test specimen. Over 22,000 of these gages were manufactured and used with a fair degree of success. Primarily because of the difficulty of shaping the sticks to conform to curved surfaces, a flexible type of bonded carbon strain gage was developed which supplanted the stick gages. In late 1942 Hamilton-Standard began to work with the bonded wire gages, and after a short period of transition the cost and technical advantage of the wire, gages were so pronounced that the carbon gages were permanently abandoned and the Simmons bonded wire gages were used exclusively. The magnitude of the Hamilton-Standard vibratory project is indicated by the fact that by 1940 over 500,000 separate measurements had been made and forty-five persons were employed on a full-time basis to study the problem. These included a number of well-qualified engineers and scientists of whom Kearns, one of defendants’ witnesses, was one. Although a young man at the time, he received the Sperry Award of the Institute of Aeronautical Sciences for the work which he did in 1939 in applying methods of measuring propeller vibration stresses in flight. For further work in the same field he was similarly honored in 1942 by the Franklin Institute which awarded him the Longstreth Medal. By 1940 Hamilton-Standard had engaged three of the outstanding experts to consult with it on the fundamental principles involved in its vibration studies. These were Dr. DeForest of M.I.T., who, with Dr. Ruge, was employed by Baldwin in 1940 to make gages for it under the Simmons patent; Dr. Den Hartog, an internationally recognized authority on vibration; and Dr. Bollay, an associate professor in the mechanical engineering department at Harvard. The Hamilton-Standard experiance is compelling proof that the Simmons invention was not obvious. Hamilton-Standard is a division of a great corporation. Its top scientists and consultants were not tyros. Its interest in obtaining the best type of measurement device was not a matter of academic concern. Lives and dollars depended upon its ability to develop and use the best possible devices for measuring propeller strains. Yet, so far as the record discloses, the possibilities of making a bonded wire strain gage never occurred to Hamilton-Standard prior to Simmons’ discovery. Even after the Simmons gage became commercially available its potentialities were not sufficiently evident for Hamilton-Standard to immediately use the gages. In fact, it took it several years to be persuaded of its worth. This in itself is persuasive proof that what Simmons did was not obvious or the utilization of mere mechanical skill. McKee v. Graton & Knight Co., 4 Cir., 1937, 87 F.2d 262, 264; National Battery Co. v. Richardson Co., 6 Cir., 1933, 63 F.2d 289, 292. The possibilities of measuring strain through its relationship to electrical resistance of carbon bonded to a test specimen had been studied by other outstanding people. A. Bloch of the Physics Department of Trinity College, Dublin, and E. H. Hull of General Electric Research-Laboratory had written articles on the bonded carbon gages in 1935 and' 1937, respectively. Apparently neither thought of substituting wire for carbon. Moreover, bonded carbon gages were studied by a group at Cal. Tech., including Simmons, in connection with the-comprehensive examination of the strain; measurement problem in the Impact Research Project conducted at Cal. Tech. Of the group there involved only Simmons thought of using a bonded wire. Although no evidence exists that Hull, Bloch or indeed Hamilton-Standard knew of the Carlson unbonded wire gage, still! if the advantages of the substitution-were as plain as defendants say, it is odd' that the possibility of the substitution! did not occur to any of them. Defendants point out that the-idea of a bonded metallic strain gage occurred to Dr. Hathaway of General Electric and to Dr. Ruge at about the same-time as it did to Simmons and offer this-as evidence of obviousness. Neither Hathaway nor Ruge wex-e men of ordinary skill in the art as 35 U.S.C. § 103 requires that they be for their discovery to be pertinent to the defense of obviousness. Each had scientific graduate degrees and were highly skilled inventors.. Dr. Hathaway has had 53 patents issued to him, and Dr. Ruge is credited with 43 more. The fact that the substitution of wire for carbon in a bonded gage occurred to Drs.- Hathaway and Ruge is therefore not significant. Again it is said that the obviousness of what Simmons did is established by the fact that his gage was forthcoming just as soon as the need for it in dynamic testing arose for the first time in the mid-1930’s. The legal predicate for this contention is sound enough. Safety Car Heating & Lighting Co. v. General Electric Co., 2 Cir., 1946, 155 F.2d 937, 939; McElrath v. Industrial Rayon Corp., 4 Cir., 1941, 123 F.2d 627, 629. But the need for a strain gage having the merit of Simmons’ existed in the field of dynamic testing long before Simmons’ discovery although undoubtedly the need was constantly accentuated by the increasing use of automobiles and airplanes. From the fact that the electrical output of carbon is 100 times greater than metallic wire, defendants argue that at the time when Hamilton-Standard was carrying on its work, recording devices had not been developed which would give the amplification needed to record the relatively weak response provided by a wire gage. Although Kearns of Hamilton-Standard testified that between 1936 and 1940 big strides had been made in obtaining resistance recordation by means of amplification, the record fails to indicate that Hamilton-Standard considered using a bonded wire gage but rejected the idea because of lack of instrumentation. The instrumentation problem did not prevent either Simmons or Ruge from recognizing the practical advantages of the bonded wire gage over prior art gages and from seeking patents thereon. Now that the Simmons gage has been acclaimed, it is easy to say that what he did was obvious. But the law has other tests of invention than subtle conjectures of what might have been seen and yet was not. Diamond Rubber Co. of New York v. Consolidated Rubber Tire Co., 1911, 220 U.S. 428, 434-435, 31 S.Ct. 444, 55 L.Ed. 527. The practiced eye of an ordinary mechanic may be safely trusted to see what ought to be apparent to everyone. Potts v. Creager, 1895, 155 U.S. 597, 608, 15 S.Ct. 194, 39 L.Ed. 275. Prior to and after Simmons’ discovery scientists and technicians of pre-eminence had been devoting their attention specifically to strain measurement by variations in electrical resistance over a long period of time. Their failure to discover what Simmons hit upon demonstrates that it was not obvious. I would indeed be bold were I, untutored in technical and scientific matters, to conclude that any ordinary mechanic skilled in the electrical strain gage art could have done what Simmons did, when in fact outstanding scientists working with the problem over a period of years failed to do it. It is argued that the Simmons combination patent merely unites old and well-known elements — bonding and wire— without producing any new or different function or operation of a surprising or extraordinary kind and hence it is devoid of the requisites of patentability. Great Atlantic & Pacific Tea Co. v. Supermarket Equipment Corp., 1950, 340 U.S. 147, 152-153, 71 S.Ct. 127, 95 L.Ed. 162; Packwood v. Briggs & Stratton Corp., 3 Cir., 1952, 195 F.2d 971, 973; certiorari denied 344 U.S. 844, 73 S.Ct. 61, 97 L.Ed. 657; rehearing denied 344 U.S. 882, 73 S.Ct. 174, 97 L.Ed. 683; Mojonnier Bros. Co. v. Tolan Machinery Co., Inc., 3 Cir., 1956, 230 F.2d 850, 851; Fowler v. Honorbilt Products, 3 Cir., 1942, 131 F.2d 153, 155. While these principles evolved in the field of mechanical patents, it may be assumed that they apply with equal force to an electro-mechanical patent such as Simmons’. From the evidence I am satisfied that the bonding of the wire did result in a new and different function or operation for the wire as against its unbonded use by Carlson. The wire in the Carlson gage was useless to measure compression strains; it would function only to measure tension strains. Furthermore, once the wire in the Carlson gage had been stretched beyond its elastic limit in measuring tension, the gage was ruined. These limitations inherent in the wire of the Carlson gage were eliminated by Simmons by bonding the wire to the test specimens. A new and different function or operation for the wire was achieved. The wire did not serve as separately it had done for Carlson. Cf. Toledo Pressed Steel Co. v. Standard Parts, Inc., 1939, 307 U.S. 350, 356, 59 S.Ct. 897, 83 L.Ed. 1334. Nor did the bonding do to carbon in the carbon gage what it did to wire in the Simmons gage. It couldn’t. Carbon is not ductile and therefore does not have elastic limit characteristics or present elastic limit problems. The contrary is true of wire which is ductile. The elements— bonding and wire — were so united by Simmons as to produce a new and useful result because of their co-action as a single entity. Griscom-Russell Co. v. Westinghouse Electric & Mfg. Co., 3 Cir., 1941, 121 F.2d 680, 682. The whole did in fact exceed the sum of its parts. Great Atlantic & Pacific Tea Co., supra, 340 U.S. at page 152, 71 S.Ct. at page 130. The ability of the wire in the Simmons gage to be stressed appreciably beyond its normal elastic limit and still faithfully maintain its predetermined strain sensitivity was a surprising result. Even Simmons didn’t recognize the inherency of that phenomenon in his invention until his lawyer Hathaway, who had learned of it through Dr. Ruge, called it to Simmons’ attention. The Simmons patent therefore does not suffer the infirmity of an unpatentable aggregation of old and well-known elements. Instead, it fully meets the test of the relevant decisions. (c) Inadequacy of Description Preliminary to discussing this defense it is necessary to explain certain technical terms, the meaning of which must be understood, if the defense is to be com-prehendible. Electrical strain sensitivity is the property which electrical conductive materials possess which causes their resistance to electrical current to change with any change in their strain. In measuring strain by means of variation in resistance the change in resistance as it relates to change in strain is frequently plotted on a graph with one axis indicating resistance changes and the other indicating strain changes. When this is done a strain-resistance “curve” is obtained. When the change in resistance is proportional to the change in strain at all degrees of strain, the strain-resistance curve will be substantially a straight line. Then it is said to be a “linear” curve and that “linearity” exists in the resistance-strain relationship. The “elastic limit” of a material is the greatest stress which a material is capable of developing without a permanent deformation remaining upon complete release of stress. When a stress is applied to a material, it is strained thereby. When a stress below the elastic limit of a material is applied, it will strain the material, but the material will return to its original dimensions on release of the stress. Where, however, a stress above the elastic limit of the material is applied, the material will not return to its original dimensions, but will remain permanently deformed. The gist of the “inadequacy of description” defense is that Simmons asserted in his specifications that the electrical strain sensitivity of any bonded wire is linear both above and below the elastic limit of the wire, that in point of fact this is not true as to all wires, and that because the patent fails to teach one skilled in the art which of many wires must be used to obtain linearity the specificity required by 35 U.S.C. § 112 has not been satisfied. Under this section of the patent law no patent can be validly obtained unless the specification contains a written description of the invention, and of the manner of making and using it, in such full, clear, concise and exact terms as to enable any person skilled in the art to make and use the invention. Undoubtedly some wires have strain-resistance characteristics which are not linear either below or above the elastic limits of the wire. This was conceded by Dr. Ruge, plaintiffs’ expert. It was likewise established by defendants’ demonstrations with wires made of nickel and Secón No. 1, respectively. Hence, the validity of the “inadequacy of description” argument comes down to this: does the patent in fact teach that any wire bonded to a test specimen in accordance with Simmons’ teaching will exhibit a linear strain-resistance relationship both above and below the elastic limit of the wire when the specimen is subjected to variable strains ? Plaintiffs rely upon three statements in the patent which they say assert a linear strain-resistance characteristic for any wire. The first is: “A still further object is to provide an improved electrical strain sensitive apparatus that has a substantial linear calibration curve * * * >\ Here Simmons is declaring linearity to be an objective of his gage. This objective can be achieved by the use of Constantan wire. Defendants concede this. Simmons’ preferred embodiment of his invention called for the use of Constantan. But even though linearity of calibration cannot be accomplished with all types of wire, linearity of calibration was only one of Simmons’ objectives. The patent discloses that Simmons had other important objectives. The first one which the patent recites is: “To provide an improved electrical strain sensitive gage that has a high degree of sensitivity, accuracy and responsiveness adapted to produce a maximum constancy of calibration in order to assure reproducible results and thereby minimize various defects arising from atmospheric influence as well as such defects as zero shifting and hysteresis.” This objective was substantially accomplished by Simmons’ gage. The next objective stated in the Simmons patent is: “A further object is to provide improved electrical strain sensitive means that has a high natural frequency whereby a uniform response is obtained to a given force, independent of the velocity of the application of the force within the limits of the working range.” Here again this objective was accomplished by the Simmons gage. The failure of a patent to accomplish all of its stated objectives will not defeat the patent if some of its objectives are accomplished by its teaching. Scovill Mfg. Co. v. Satler, D.C.Conn.1927, 21 F.2d 630; Kirchberger v. American Acetylene Burner Co., D.C.ND.N.Y.1903, 124 F. 764; affirmed, 2 Cir. 1904, 128 F. 599; Eames v. Cook, C.C. Mass.1860, Fed.Cas.No.4,239. This is a complete legal answer to plaintiffs’ contention that the inability of all wires to give a substantial linear calibration curve, which was one of Simmons’ stated objectives, renders the patent invalid. To establish that Simmons was claiming linearity for all types of strain gage wires, plaintiffs next point to the statement in the patent which is italicized: “Except in extreme forms, the filament sensitivity is not affected by the geometry of the winding. In all forms the per cent change in resistance per unit elongation is practically constant. * * * ” When the italicized words are read in context it is obvious that Simmons is simply saying that the percentage change in resistance per unit elongation will not be affected by any variation in the geometry of the winding of the wire. The statement is not a representation of any kind with respect to the result to be expected when different types of wires are used. The last statement in the patent which plaintiffs point to to establish that the linearity was claimed for all types of wire reads: “A phenomenon inherent in my improved combination of a fine wire filament bonded throughout its effective length to a test specimen or body to be variably strained is that the filament may be stressed appreciably beyond its normal elastic limit or yield point and still faithfully maintain its predetermined strain sensitivity, this phenomenon occurring even during repetitive loading.” • This says nothing about linearity. It refers only to the- faithful maintenance of the predetermined strain sensitivity of the wire even when the wire is stressed appreciably beyond its normal elastic limit. The patent defines what Simmons meant by electrical strain sensitivity. He says that it is the principle that the electrical resistance of materials varies with the strain thereof. This variation in relationship may or may not be linear. Simmons therefore' does not say that his bonded strain gage will result in linearity regardless of what wire is used in the gage. Furthermore, Simmons’ purpose “to produce a [gage with] maximum constancy of calibration in order to assure reproducible results” (supra, 169 F.Supp. at page 19) shows that he was not interested solely in accomplishing a substantially linear calibration as plaintiffs argue. Simmons’ interest was in achieving “constancy” of calibration whether linear or non-linear. Other portions of the patent support the view that although Simmons recognized the desirability of linearity, he did not assert it to be the crux of his patent. Simmons says that his strain gage employs “broadly” the principle of electrical strain sensitivity; that the strain sensitivity of various materials may be obtained from standard tables “or readily determined by experiment”; that the calibration of a strain sensitive filament may be affected by progressively loading in a materials testing machine and “observing the corresponding variations in electrical resistance of the strain sensitive filament”; that the principles that govern the action of the filament allow “accurate reproducible results to be obtained”; and that the filament may be repeatedly stressed beyond its normal elastic limit “while the filament retains its said predetermined manner of resistance change.” These statements are consistent with a teaching that the bonding of the wire will insure reproducible results. They contain nothing to suggest that such reproducible results were restricted to responses which were linear. On the contrary, the generality of the expressions which Simmons used is inconsistent with a claim that any wire may be depended upon to give a linear response either above or below its elastic limit. Gages susceptible of linear calibration have a decided advantage over other gages since by advance calibration the user may be given a number or “gage factor” by which the resistance change value may be multiplied in order to arrive at the strain value. Baldwin, in all of its gages listed in its price list, uses a wire which has the advantage of a linear relationship within the recommended working range, and the package containing each of these gages discloses its “gage factor”. However, Baldwin itself has sold gages which do not have a linear response. These had to be calibrated from a graph or chart containing a non-linear curve instead of from a “gage factor” in the form of a number. A linear response therefore is not essential to the successful operation of a gage constructed in accordance with Simmons’ teaching. Defendants’ “inadequacy of description” argument rests upon the premise that the patent asserts that a linear strain-resistance relationship will obtain with any type of wire both below and above its elastic limit. The fact is the patent makes no such claim. (d) New Matter in Amendment to Application Defendants assert that the patent is invalid because “new matter” not inherent in the original application was added to the patent in violation of 35 U.S.C. § 132. The “new matter”, defendants say, was the reference in an amendment to a “phenomenon” of Simmons’ invention, viz., the ability of the filament to be stressed appreciably beyond its normal elastic limit and still faithfully maintain its predetermined strain sensitivity during repetitive loading. The action of the Patent Office in permitting the amendment constituted an implicit determination that no “new matter” was included in it. Defendants’ arguments fail to convince me that the action of the Patent Office was clearly erroneous. Under the circumstances, I am not disposed to take a position at variance with its action. Cf. Helms Products, Inc., v. Lake Shore Mfg. Co., 7 Cir., 1955, 227 F.2d 677, 679. Unclean Hands (a) Fraud in the Patent Office This defense is based upon defendants’ assertion that plaintiffs knowingly made false statements to the Patent Office which induced it to grant the Simmons patent following its earlier rejection. In essence, defendants charge that plaintiffs perpetrated a fraud on the Patent Office. If this is true, the patent is unenforceable. Precision Instrument Mfg. Co. v. Automotive Maintenance Machinery Co., 1945, 324 U.S. 806, 65 S.Ct. 993, 89 L.Ed. 1381. There it was held that the doctrine of unclean hands barred a plaintiff from enforcing a patent against an infringer when the Patent Office had issued the patent upon the basis of perjured testimony and suppression of facts which plaintiff had reason to know about. If, however, the proof fails to establish with “any reasonable degree of certainty that there has been a deliberate misrepresentation” in the Patent Office, the defense of unclean hands cannot be successfully asserted. Helene Curtis Industries v. Sales Affiliates, D.C.S.D.N.Y.1954, 121 F.Supp. 490; affirmed 2 Cir., 1956, 233 F.2d 148; certiorari denied, 1956, 352 U.S. 879, 77 S.Ct. 101, 1 L.Ed.2d 80 . Specifically defendants contend that plaintiffs knowingly represented to the Patent Office, contrary to the fact, that any wire used in accordance with Simmons’ teaching would always produce a linear relationship between variations in strain and change in resistance and that but for such representation the patent would not have issued. Plaintiffs concede that all wires do not give a linear strain-resistance response. A definition of the terminology critical to the discussion which follows is found at 169 F.Supp. 18, supra. Defendants’ argument runs thus: Neither Simmons’ original application filed February 23, 1940 nor its two amendments filed on March 17, 1941 and May 24, 1941, respectively, were sufficient to cause the Patent Office to take favorable action by issuing the patent. The rejection which occurred on June 10, 1941, although based in part upon certain technical deficiencies, was fundamentally the result of the view of the Patent Office that Simmons’ claimed invention was an obvious substitution of elements disclosed in the prior art and failed to reveal “the occurrence of new and unobvious results”. Defendants point out that following this rejection, Simmons, on November 19, 1941, again amended his application to meet the technical objections of the Patent Office and then asked for a reconsideration of the basic objection of unpatentable substitution. Defendants say that at this point, Simmons, in order to revitalize his application by demonstrating that the bonding of the wire accomplished a new and unobvious result, made two deliberate misstatements to the Patent Office upon the basis of which the patent issued. The first was: “ * * * a phenomenon is the fact that the filament may be repeatedly stressed beyond its elastic limit and still maintain its strain sensitivity factor”. The parties are in disagreement as to the meaning of “strain sensitivity factor”; and defendants’ argument hinges in part upon its resolution. According to defendants the statement that the bonded wire will maintain its “strain sensitivity factor” even though the wire is repeatedly stressed beyond its elastic limit, means that any type of wire used in the gage will provide a linear relationship between the change in strain and change in resistance. The word “factor”, defendants argue, means a constant and not a variable numerical relationship. On the other hand, plaintiffs assert that Simmons never intended that “strain sensitivity factor” should be limited to a linear or constant numerical relationship, but that he used the term in a broader sense to embrace either a constant or a variable numerical relationship depending upon whether or not a wire capable of a linear response was used in the gage. At the time when Simmons made the “strain sensitivity factor” statement which defendants condemn as false, Baldwin, through its house patent attorney, Hathaway, was in control of the prosecution of the Simmons application. It was also in control of a patent application for a strain gage which Dr. Ruge had filed five months prior to the Simmons application. Baldwin was therefore in privity with both inventors at all times during the prosecution of their respective patent applications. This fact is of critical importance in determining the meaning to be accorded to “strain sensitivity factor” in the Simmons application. The phrase “strain sensitivity factor”