[Trade Journal]
Publication: Federal Supplement
St. Paul, MN, United States
vol. 18, p. 191-213, col. 1-2
CASES
ARGUED AND DETERMINED
IN THE
DISTRICT COURTS OF THE UNITED STATES
AND THE
COURT OF CLAIMS
HARTFORD-EMPIRE CO. v. SWINDELL BROS., Inc. (AMSLER-MORTON CO., Intervener).
No. 2278.
District Court, D. Maryland.
Jan. 30, 1937.
1. Patents ؎ 240
A patent to the first person to invent mechanism to perform a particular work is infringed by later machine substantially incorporating the mechanism to do the same work, but a patent for an improvement on such a machine does not cover the machines of later inventors, who improve the same machine in a substantially different manner.
2. Patents ؎ 9
If the advance toward thing desired is gradual so that no one can claim the complete whole, each inventor is entitled to the specific form of device which he produces.
3. Patents ؎ 174
Inventor of first improvement cannot invoke doctrine of equivalents to suppress any other improvement which is not a mere colorable invasion of the first.
4. Patents ؎ 328
Mulholland, reissue patent. No. 17,263, claims 1, 2, 7, 8, 44, 45, 46, 49, 50, 51, 52, and 53; Ingle patent No. 1,583,046 claim 5; and Mulholland, patent No. 1,840,463, claims 1-5, inclusive, for apparatus and method of annealing glassware there must be identity of function and claims 1-5, inclusive, for apparatus and method of annealing glassware held not infringed.
5. Patents ؎ 167(1¼)
Patent claims calling for means of heating, apparatus for annealing glassware and controlling temperature therein must be limited to means described in specifications and emphasized by patentee as basis for patentable difference' from the prior art.
6. Patents ؎ 235(1)
To constitute infringement of patent there must be identity of function and substantial identity of the way of performing such function.
7. Patents ؎ 172
While any patent is entitled to some, range of equivalents, the range depends on and varies with the degree of invention, and claims, not marking any high degree of invention in, view of prior art are not entitled to broad, range of equivalents.
8. Patents ؎ 177
That patentee's apparatus as used in commercial practice is most efficient and economical apparatus, so far produced does not entitle patent claims for particular features of the apparatus to a liberal range of equivalents where the, excellence of the apparatus results from an aggregation or combination of features selectively taken from the prior art and coordinated.
In Equity. Suit for infringement of patent by the Hartford-Empire Company against Swindell Bros., Inc., in which the Amsler-Morton Company intervened.
Bill of complaint dismissed.
Edwin F. Samuels, of Baltimore, Md., Wm. J. Belknap, of Detroit, Mich., and Robson D. Brown and Sidney F. Parham, both of Hartford, Conn., for plaintiff.
Cook & Markell, of Baltimore, Md., Wm. B. Jaspert, of Pittsburgh, Pa., and Lawrence C. Kingsland, of St. Louis, Mo., for defendant.
CHESNUT, District Judge.
The three patents involved in this equity suit all relate to the annealing of glassware, and more particularly hollow glassware, such as bottles. Annealing is a process of heating and cooling. The pleadings in fact present for consideration six of the plaintiff's patents but counsel have agreed to rest the case upon three and to limit the number of claims in each to those hereinafter enumerated. The three patents and the particular claims thereunder for consideration are as follows: Mulholland reissue, No. 17,263, April 9, 1929, claims Nos. 2, 7, 44, 49, 50, and 52 to be taken as typical; Ingle No. 1,583,046, May 4, 1926, claim 5; Mulholland No. 1,840,463, January 12, 1932, claims 1 to 5, inclusive, with claim 5 typical.
The plaintiff is a Connecticut corporation which designs, builds and licenses the use of lehrs for the annealing of glassware. The defendant, Swindell Bros., Inc., is a Maryland corporation with plant in Baltimore City, manufacturing glass bottles. It uses three of the plaintiff's lehrs under license agreement and it also owns and uses two lehrs designed and made by the Amsler-Morton Company, a Pennsylvania corporation, which has been permitted to intervene in the case and as maker of the alleged infringing machine, has assumed the burden of the defense of this patent infringement suit for injunction and accounting.
The emphasis of the defense is placed on the point that the intervenor's apparatus does not infringe that of the plaintiff, but if infringement should be found, then the invalidity of the plaintiff's patents in view of the prior art is advanced as a further defense. As to the latter, the plaintiff replies that the defendant (and consequently the intervenor also) is as licensee of the plaintiff's apparatus, and by virtue of a special stipulation in the license agreement, estopped to deny the validity of the plaintiff's patents; but the intervenor says this position is not tenable because the alleged infringing device is entirely outside the scope of the patent agreement and therefore the estoppel does not arise. It may be said at once that it will not be necessary to adjudicate this issue in this case because I have reached the conclusion that there is no infringement. In passing it may, however, be pointed out there is substantial support for the intervenor's position in the very persuasive reasoning of Judge Dennison in the case of Indiana Mfg. Co. v. Nichols & Shepard Co. (C.C.) 190 F. 579, which was adopted and applied by Judge Sanborn in the later case of Symington Co. v. National Malleable Castings Co. (D.C.) 257 F. 564. See, also, International Burr Corp. v. Wood Grinding Service (C.C.A.2) 34 F. (2d) 905; Eskimo Pie Corp. v. National Ice Cream Co. (C.C.A.) 26 F. (2d) 901; Paramount, etc., Co. v. Moorhead, etc., Co. (D.C.) 251 F. 897, 902, affirmed (C.C.A.) 260 F. 841; Good Humor Corp. v. Bluebird Ice Cream (D.C.) 1 F. Supp. 850, affirmed (C.C.A.) 66 F. (2d) 1013; and Tate v. B. & O. R. Co. (C.C.A.4) 229 F. 141. And it is not denied by plaintiff's counsel that Swindell as the defendant in this case may refer to the prior art for the construction of the scope of the plaintiff's patents in support of defendant's claim of noninfringement. Westinghouse E. & Mfg. Co. v. Formica Insulation Co., 266 U.S. 342, 45 S. Ct. 117, 69 L. Ed. 316.
The intervenor for itself and for the defendant raises the defense of laches on the part of the plaintiff in the institution of the suit. It is pointed out that the Amsler-Morton Company's apparatus has been extensively in use in its present form since early in 1927; that the plaintiff became substantially advised as to its structure and operation at least as early as 1928 and thereafter on July 26, 1928, filed its application for its reissue patent No. 17,263, for the purpose of more clearly, in one or more of the claims, covering the Amsler-Morton lehr without successful defense based on a prior use by the Amsler-Morton Company in a lehr built for Frey & Son in 1919; and that the reissue patent as applied for was issued on April 9, 1929, and shortly thereafter the plaintiff charged the defendant with infringement under the reissue patent, which was denied by the Amsler-Morton Company's patent counsel in an extended letter giving the reasons for the denial. It is said the issue between the plaintiff and the Amsler-Morton Company was thus definitely joined on the question of patent infringement but nevertheless no suit has yet been brought by the plaintiff directly against the Amsler-Morton Company up to the present time. The plaintiff, however, takes the position that the defense of laches is a personal one to the defendant, Swindell, and therefore any delay in suit by the plaintiff against the Amsler-Morton Company is not properly in issue in the case. See Chandler & Price Co. v. Brandtjen & Kluge, Inc., 296 U.S. 53, 56 S. Ct. 6, 80 L. Ed. 39. And as to Swindell, it is pointed out by the plaintiff that the former acquired the alleged infringing apparatus only in April, 1931, and that suit was instituted here on July 30, 1934. Plaintiff's counsel offers an explanation and excuse for such delay as occurred by reason of lack of full and precise information as to the Amsler-Morton apparatus until 1930, and lack of reasonable opportunity to sooner sue due to other patent litigation. The theory of the intervenor here is that the plaintiff's long delay and failure even up to the present time in suing the intervenor operates as an implied license to it which it can validly pass on to Swindell. It is certainly doubtful whether laches alone without some positive element of estoppel, such as change in position, would be so operative. The plaintiff's excuses for delay in suing the Amsler-Morton Company are not impressive, but it would seem that even if laches were sufficient in this case to preclude an accounting as against Swindell, it would not be sufficient to deprive the plaintiff of its right to an injunction if otherwise existent. See Menendez v. Holt, 128 U.S. 514, 524, 9 S. Ct. 143, 32 L.Ed. 526; Denominational Env. Co. v. Duplex Env. Co. (C.C.A.4) 80 F.(2d) 186, 193; A. R. Mosler & Co. v. Lurie (C.C.A.2) 209 F. 364. It is, however, unnecessary to determine this issue of laches in this case in view of the conclusion already announced with regard to infringement.
Before detailed consideration of the plaintiff's several patents, and comparison of its apparatus with the alleged infringing apparatus of the Amsler-Morton Company (hereinafter some times for brevity called "Amco"), it is desirable to state very briefly, but sufficiently for the purpose of understanding the patents in the case, the essentials of the manufacture of glassware. The art is indeed a very old one. It was practiced to some extent by the Egyptians, more largely by the Romans, quite extensively in the Middle Ages in Western Europe, and also in this country during the Colonial period, and at all times subsequent thereto. Very briefly, the raw materials for glass making are melted in a large furnace or retort at a very high heat (about 2,500 degrees Fahrenheit) and the portions of the viscous mass are poured into molds or form-shaping machines at a temperature of about 1,800 degrees. From these molds the glassware thus formed, still in a plastic state, is transferred either manually or by an automatic conveyor a short distance into a tunnel-like structure called a lehr, about 60 to 70 feet in length, which is heated at the receiving end to a temperature of approximately 1,000 degrees, with a temperature gradient in the end. The glassware is transported slowly through the lehr on an automatic conveyor belt. The function of the lehr is to first reheat the glass and then gradually and uniformly cool it. This is called annealing. Plaintiff's patents all relate to the structure of the lehr made by it with one or more claims also for the method of annealing involved.
When the hollow glassware, in bottle shape for instance, is removed from the shaping molds the outside, which is in contact with the mold, is somewhat cooler than the inside and therefore the relatively greater contraction of the glass on the outside sets up strains and stresses which, if the glassware were allowed immediately thereafter to cool at the normal factory temperature, would cause it to at once break as a result of its own internal forces or to readily break thereafter upon slight pressure. To obviate this it as necessary that the glassware should be quickly placed in the lehr where for a certain period of time it will be again subjected to a relatively high temperature sufficient to renew its plasticity, and then it is allowed to cool in the slowly decreasing temperature until the whole of the glass article has become permanently set by uniform and gradual cooling. The range of temperature which must be maintained during, this annealing stage in the manufacture of glassware is from 1,000 degrees F. to approximately 750 degrees. It is essential, therefore, that this temperature be, maintained in the lehr during the annealing stage. It is called the critical range of temperature. The linear extent of the lehr in which this, critical range of temperature must be maintained depends upon the amount and thickness of the glassware and is, of course, also affected by, the rate of forward progress of the glassware through the lehr. After the glass has successfully passed the annealing stage the remaining function of the lehr is merely to gradually reduce the temperature during the further progress of the glassware until it is at a sufficiently low temperature to be handled at the delivery end of the lehr; and after inspection, packed for shipment The particular, range of temperature at the receiving end of the lehr is therefore not so vitally important as that to be maintained during the annealing stage; but is of course important for the gradual reduction of temperature. In commercial practice, for efficiency and economy of operation, it is obvious that the most desirable characteristics for a lehr are economy in fuel, which however must be sufficient, to maintain the required temperature during the annealing stage, and rapidity of progress through the lehr, in order to speed, up mass production.
The history of the art of glass making, over the last 50 years, shows a steady improvement in construction for economy and efficiency of operation of lehrs. The earliest form of apparatus for annealing was merely a closed oven in which the glass was placed after formation, in desired shape by blowing, and while it was practically cold. The oven was then heated to the required temperature which was maintained as long as necessary, after which the the heating was discontinued and the glass allowed to gradually cool before it was manually removed from the oven; which had been sealed during the operation. This process was entirely efficient as to the quality of the annealing, but was necessarily slow in operation. With the introduction of machinery for shaping the glass, there came also the necessity of speeding up the annealing process for mass production. The introduction of the lehr was the response of the trade to this demand. The earliest form of lehr in use about 50 years ago, consisted of a brick structure forming the exterior walls, necessarily placed for stability on firm foundations, an open gas flame within the forepart or receiving end of the lehr and some form of conveyor operated either by hand or machinery for the transportation of the glassware through the tunnel. As compared with present practice, this early form of lehr had numerous disadvantages in that the products of combustion of the open flame often discolored the glassware, the rate of progress through the lehr was very slow, varying from 4 to 8 hours, and the absence of an efficient control of the temperature gradient resulted in a comparatively high percentage of breakage of the glass during annealing, which varied from 5 to 10 per cent. These lehrs were known as "open fire" lehrs. With marked improvement in the molds for forming devices and the speeding up of mass production came also improvements in the design, structure and efficiency of the lehr. The first important change was to enclose the products of combustion from the fire in flues which were variously arranged around the sides and length of the lehr. This prevented the discoloration of the glassware, and by the use of dampers variously spaced in different parts of the flues afforded a means for some control over the temperature in the lehr. This improvement came into general use shortly after the turn of the century. The next great advance came during or shortly after the World War and is illustrate ed by the types of lehrs constructed by the Amsler-Morton Company, in the installation, made by it for H. C. Frey [sic] Fry & Sons, manufacturers of glassware in 1919, and by the Dixon Glass Company for the Capstan Glass Company, and for the Owens Bottle Company of Charleston, Va. These lehrs had outlets for the flues (which were both longitudinal and vertical) at various intervals in the length of the lehr, which in turn were controlled by dampers, so that, the distribution of the heat from the firebox in the forepart of the lehr Could be more efficiently regulated throughout, that portion of the lehr in which the annealing of the glassware occurred. In the meantime improvements had been made in the form of the conveyor belt used. These new lehrs added greatly to the efficiency of production, whereby the amount of, breakage and necessary rejection was reduced to about 2%, and the time required for annealing and discharge from the lehr was very materially reduced. This type of lehr, however, was still of the fixed stationary variety with external walls of brick.
The. next marked improvement was the introduction about 1920 of the movable type of lehr which is now used both by the plaintiff and by the Amsler-Morton Company. This type of lehr his instead of brick walls sheet metal heavily insulated with rock wool. It is much lighter in construction than the brick lehr and generally is narrower in width (being about 3 to 4 feet wide while the brick lehr was about 10 feet wide), is equipped with a more rapidly operating conveyor belt, and by reason of its smaller size and less weight, is capable of location at will in relation to the forming machines. In the trade it is generally called the "unit" type of lehr. It is generally about 70 feet in length.
[1-3] First: In construing the plaintiff's patents and determining the question of infringement, it is to be importantly noted that we are not dealing with pioneer patents "but with those that represent only improvements on an apparatus in an art that is very old and in a field that is literally crowded with prior patents. The doctrine of patent law which is applicable to this situation is well and succinctly summarized in Section 230 of the 6th Ed. of Walker on Patents, Vol. I, where the author states the principles to be derived from the four leading, cases of McCormick v. Talcott (1857) 20 How. 402, 15 L. Ed. 930; Chicago & N. W. Railway Co. v, Sayles (1878) 97 U.S. 554, 24 L. Ed 1053; Morley Sewing Machine Co. v. Lancaster (1889) 129 U.S. 263, 9 S. Ct. 299, 32 L. Ed. 715, and Kokomo Fence Machine Co. x. Kitselman (1903) 189 U. S. 8, 23 S. Ct. 521, 47 L. Ed. 689:
"The meaning of these four cases seems to be that every inventor is entitled to claim whatever he was the first to invent. If A. B. is the first to invent mechanism to, perform a particular work, and if his mechanism is substantially incorporated into subsequent machines which do that work, then A. B. is entitled to such a construction of his patent as will be infringed by those later machines; but if C. D. is a mere improver on A. B.'s machine, C. D. is not entitled to such a construction of his patent, as will cover the machines of still later inventors, who have improved on A. B.’s machine in a substantially different manner. It follows from these doctrines that C. D.’s patent must be construed in the light of A. B.'s machine, and indeed in every other similar and older structure; which is the same thing as saying that every patent must be construed in the light of the state of the art, at the time the invention it covers was produced."
And still again:
"But if the invention claimed, be itself but an improvement on a known machine, by a mere change of form or combination of parts, the patentee cannot treat another as an infringer, who has improved the original machine, by use of a different form or combination, performing the same functions. The inventor of the first improvement cannot invoke the doctrine of equivalents to suppress any other, improvement which is not a mere colorable invasion of the first."
[4] With this general, background of the art we come to a particular, consideration of the first of the three patents in suit. It is the Mulholland reissue patent No. 17,263. We are told by the patentee in the opening of his specifications that his invention relates to a method of and an apparatus for annealing glassware and more specifically to the annealing of glass-ware in a lehr of the tunnel type in which the ware passes in procession through the tunnel whose temperature varies from end to end. Something of the history, of the art is then set out and the patentee proceeds to state the objects of his invention to be in general: "To produce better annealing of glassware, to save as much fuel as possible in the annealing, and to reduce the time of annealing as well as to overcome or, minimize the disadvantage of tunnel lehrs. More specifically, the object is to create a proper environment through which the glassware may be moved continuously on a conveyor and in which it may be, subjected as nearly as possible, to the ideal cooling controlling the temperature throughout the length of the lehr, to overcome uncontrolled air currents within the lehr; and to control the local convection currents within the tunnel and utilize them to produce the desired thermal environment and as nearly as possible a uniform temperature for the glassware. To reach his objective he states that he provides a lehr having a plurality of lower flues extending longitudinally beneath the tunnel and a plurality of upper flues extending longitudinally above the tunnel, all of said flues being provided with damper-controlled openings at spaced intervals throughout their length and communicating with the outside atmosphere."
It is further pointed out that in operation the heated gases from the firebox at the receiving end of the lehr pass through the lower flues and by operation of the dampers at spaced intervals the amount of heat delivered in various areas or zones of the longitudinal length of the flues can be measurably controlled by opening the dampers in the flues to let in cool air from the factory atmosphere, so that of course the temperature in the flues containing the hot air can be lowered. And a further reduction of temperature is accomplished by the cooler, factory air being sucked or blown into the upper flues and in turn measurably regulated by their damper control openings at spaced intervals whereby more or less of the cool air is allowed to escape to the outside atmosphere at selected intervals. It is to be noted, also that the heated air travels from the receiving end toward the delivery end while the cool air travels in the opposite direction. The range of temperature in the heated flues is also subject to regulation by the volume and intensity of heat generated in the firebox and provision is made there also for the introduction of a desired amount of outside air to be mixed with the products of combustion. The amount of temperature in the lehr is therefore affected by two factors: (1) The positive amount of heat generated in the burner and passing through the heated flues and radiated of course therefrom unto the tunnel of the lehr which, however, may be reduced by the amount of cooler air let in from the valve in the flue placed just to the rear of the valve in the flue placed just to the rear of the firebox, thus diluting the products of combustion, and may be further reduced by opening the dampers in the inlets to the flue spaced much further to the rear of the flue and beginning in practice near the end of the annealing stage within the lehr; and (2) by the wholly cool air sucked into the upper flues which in turn may be reduced in length of operative effect by the opening or closing of the spaced dampers in the outlets from the upper flue. As has been pointed out, what is desired in operation is a high temperature at the receiving end of the tunnel to be, maintained for a certain part of the length of the tunnel at a temperature not less, than 750 degrees, and a relatively lower temperature gradually decreasing through the remaining length of the tunnel and some approximate control over the length of the zone in which this critical range of temperature for the annealing of glassware is required, to be regulated through the operation of the dampers whereby the length of the flue containing the highest heat measuring from the firebox can be lengthened of shortened, and similarly the check on the higher temperature and consequent lowering of temperature measuring from the delivery end may be influenced by the amount of cooling air in the upper flues in which the air current moves in the opposite direction. Thus the higher heated zone within the tunnel from the receiving end may be lengthened or shortened as desired for the particular glassware that is being annealed. This relation of upper and lower flues carrying respectively hot and cold air, it is claimed, has the incidental advantage of causing the heated air to rise from the bottom to The top of the lehr, thus establishing convection currents in a vertical direction only and tending to prevent the longitudinal air currents flowing in from the cool delivery end toward the heated receiving end, which was a disadvantage of the older form of lehrs because it tended to destroy the uniformity of temperature and to disturb its general decline from the receiving end to the delivery end. Further elimination of these longitudinal air currents is also aimed at by the feature of the arrangement of the conveyor belt which, when entirely within the tunnel as to both the upper and lower surfaces, likewise tends to create longitudinal air currents. In plaintiff's lehr two things are done with respect to the conveyor belt to obviate this tendency; one is to incline the conveyor belt slightly from the receiving end toward the delivery end; and the other is to have only the ware-bearing surface of the conveyor belt within the tunnel, the return strand passing underneath the tunnel. The relative locations and the inter-action of the longitudinal hot and cold air flues constitutes an important feature of the structural arrangement of the lehr according to the specifications of the patent.
Additional details of construction as indicated in the specifications are that the belt of the endless conveyor is composed of woven wire fabric, the ware-bearing strand of which rests upon the flat floor of the tunnel; and it is said: "By reason of the light weight and open construction of the conveyor, it has low heat capacity and relatively greater surface area in proportion to its mass, and therefore follows very closely the temperature of its environment." And it is also noted in the specifications that "the roof of the upper wall of the tunnel is constructed of metallic sheets provided with a plurality of parallel longitudinal extended corrugations substantially V shaped in cross-sections. These corrugations enclose the cooling flues mentioned above, for conveying cooling air adjacent to the top of the tunnel, and they also provide a roof for the tunnel having a relatively large heat-absorbing surface in comparison to the width of the tunnel, and their formation also tends to equalize the temperature transversely of the tunnel:" The drawings accompanying the application for the patent also disclose these particular features of construction.
It is apparent from the file wrapper of the patent that the patentable difference over the prior art which induced the granting of the patent is attributable very largely if not entirely to that Feature of the patent which provides for the dilution of the hot gases in the lower flue by the inlets of outer air at spaced intervals controlled by dampers as previously explained. And it, should be also noted that practically every feature of this particular construction has been anticipated in some prior patent or prior use, as disclosed by the testimony in this case as to prior art, with the single exception of the dilution of the hot gases by the outer air inlets. With this analysis of the patent we come now tb a consideration of the construction and scope of the claims in suit. Claims 1 and 2 are for the method of annealing glassware and claims 7, 44, 49, and 52 are for the apparatus. It will be sufficient to consider the apparatus claims as there is no significant difference between the method and the function of the apparatus.
Plaintiff's counsel submit the apparatus claims, Nos. 7, 44, 49, and 52 as typical or example claims. They are as follows:
"7. A lehr for annealing glassware comprising a tunnel, a flue associated with said tunnel, means for causing a heating medium to flow through said flue, and means for reducing the temperature in said flue selectively at any one of a plurality of intervals along said flue, and for thereby changing at will the temperature within said tunnel.
"44. A lehr for annealing glassware comprising a tunnel, a flue associated with said tunnel, means for causing a heating medium to flow through said flue, the said flue being divided into a plurality of independently controllable heating zones, and means, including spaced dampers, for increasing or decreasing, at will, the temperature in any of said zones.
"49. A lehr for annealing glassware comprising a tunnel, a longitudinal flue extending beneath said tunnel, means for causing a heated medium to flow through said flue to heat directly the bottom only of said tunnel; said flue being divided into a plurality of independently controllable zones, and means for varying the temperature drop in contiguous zones from the hotter toward the cooler end of said tunnel.
"52. A lehr for annealing glassware comprising a tunnel, a conveyor of low heat mass movable through said tunnel for transporting the ware therethrough, while permitting sensitive control of the transference of heat to and from the ware, a flue associated with said tunnel and adapted to conduct a heated medium therethrough, said flue having a plurality of contiguous controllable temperature controlling zones, means, for causing a heated medium to flow through aid flue, and means including spaced dampers for independently controlling at will the temperature drop in any of said zones, whereby the temperature of the ware may be accurately controlled by temperature of the medium in the flue, and whereby the ware is made quickly responsive to such control."
The critical phraseology in each of said claims has been italicized for clarity.
Analyzing these claims we find that No. 7 is perhaps the broadest in its literal scope as it does not define the means for reducing the temperature in the heated flue at selected intervals. Claim 44 is a little more specific in that it expresses that the means for controlling temperature include spaced dampers. Claim 49 defines the heated flue as "a longitudinal flue extending, beneath said tunnel whereby the bottom only, of the tunnel is heated."
Claim 52 is more specific as to the plaintiff's actual structure. It introduces an element of the conveyor belt as "a conveyor of low heat mass movable through said tunnel for transporting the ware therethrough while permitting sensitive control of the transference of heat to and from the ware." Otherwise it is substantially similar to claim 44. The conveyor referred to is the woven wire belt for moving the glassware and will be more particularly considered under the Ingle patent in suit. Claim 44 was claim 51 of the Mulholland patent which was originally issued as patent No. 1,571,137, January 26, 1926. It became claim 44 in the reissue patent; and claim 52 of the reissue patent is new to it. It appears from the file wrapper of the reissue patent as further explained by counsel for the plaintiff, that the occasion for applying for the reissue patent was that after its original issue on January 26, 1926, and before applying for the reissue patent, patent counsel for the plaintiff on inquiry from the Amsler-Morton Company, learned that the latter contended that its installation of a lehr at the plant of Frey [sic] Fry & Company in 1919 was a prior use which invalidated the claim 51, of the original patent, now 44 of the reissue patent, and there fore claim 42 was drawn to be, more specific by including in the patentable combination the element of the specially described belt conveyor.
It will be noted that none of these claims include as a feature of the patent the important element of the cold air flue which is stressed in the specifications.
Nor is any claim made for the so-called unit type, constructed lehr, as contrasted with the older stationary type; nor is there any claim for the structural features of the unit type of lehr consisting in the substitution of sheet metal for the older brick walls, nor for the insulation thereof. All these features are clearly shown by the testimony to have been anticipated in the art long prior to the patent in suit. The only features of the claims which are involved in this issue of infringement are (1) the use of the longitudinal lower flues; (2) the dilution of hot air therein by the dampered inlets from the outer air at spaced intervals; and (3) the nature and type of the conveyor belt. The last of these will be considered more fully in connection with the Ingle patent. It is sufficient here to say with, regard to the particular patent now being considered that the defendant's conveyor belt, although of woven wire, is differently constructed and applied in the lehr from the, plaintiff's arrangement. In argument plaintiff's counsel conceded that no claim of the patent in suit is broad enough to base infringement only on defendant's use of the lower flue which indeed, is clearly shown to have been previously used in the art. Indeed it may be said, that the testimony shows in prior use or disclosure almost every conceivable variety of arrangement of flues in these lehrs, both, lower and upper, horizontal and vertical, communicating and separate. And the testimony as to the prior art shows very clearly that practically every feature of this reissue patent has been anticipated with, the single exception possibly of the cool air inlets for the heated flue. The prior art in this case is very fully shown in the extended testimony of the defendant's expert witness, Schwartz. After fully describing, the patent in suit, and comparing the claims in issue with the defendant’s apparatus, he very briefly and succinctly summarized his testimony by saying:
"I will just say briefly, in summing up the principles the principles found in the defendants lehr of passing hot gases longitudinally through a tunnel which has an endless conveyor traveling over that flue, and the taking off of gases at intervals along the tunnel, is found in the defendant's earlier lehr at the Frey [sic] Fry Glass Company; it is found in the Milner patent and in the lehrs built in accordance with the Milner patent, at the Capstan Glass Company and at the Owens Bottle Company, it is also found in the Cruikshank patent and in the Pike patent, and it is found in the Hemingray installation of the defendant," — all more than two years prior to the application for the patent in suit.
He continued, referring to the prior uses mentioned and particularly to the outlets from heated flues at spaced intervals in the former installations, which are comparable to similar devices in the defendants structure, as follows:
"Now by those uptakes, those methods of regulation, the temperature gradient and the annealing curve along the tunnel could be modified at will by those dampers that were in those uptakes."
[5] "Other patents specifically relating to lehrs for annealing glassware and printed, publications more than two years prior to the application for the reissue patent very fully show that it was old in the art to use a heating flue longitudinal of the length of the lehr in some cases placed at the bottom of the lehr and underneath it and in other cases at the top; so that particular feature of claim 49 was of itself by no means new in use by Mulholland. In my opinion the Claims of the reissue patent relied on and above quoted must in respect to the means of heating the lehr and Controlling the temperature in the tunnel, be limited by construction to the means therefor described in the specifications of the patent and emphasized by the patentee as shown by the file wrapper as a basis for the establishing of a patentable difference from the prior art, that is, to cold air inlets for the lower hot flue, with damper control. As was said by Judge Soper in this court in Standard Brands, Inc., v. Federal Yeast Corp., 38 F. (2d) 329, 338:
"Meritorious patents are: frequently saved by interpreting the language of the claims so as to include restrictions on limitations appearing in the specification. Bisight Co. v. Qne piece Bifocal 'Lens Co. (C.C.A.) 259 F. 275, 276; Van Ness v. Layne (C.C.A.) 213 F. 804, 807; Fowler & Wolfe Mfg. Co. v. McCrum-Howell Co. (C.C.A.) 215 F. 905, 909; Permutit Co. v. Wadham (C.C.A.) 13 F. (2d) 454, 458; Gibbs v. Triumph Trap Co. (C.C. A.) 26 F. (2d) 312; Smokador Mfg. Co., Inc., v. Tubular Products Co. (C.C. A.) 31 F. (2d) 255, 257."
And in the later case of Denominational Envelope Co. v. Duplex Envelope Co., 80 F. (2d) 186, 192, it was also said by Judge Soper; speaking for the Circuit Court of Appeals, that:
"Of course the claim as allowed must be read and interpreted with reference to the rejected Claims, and to the prior state of the art, and cannot be construed to cover what was rejected by the Patent Office or disclosed by prior devices. Doughnut Machine Corporation v. Joe-Lowe Corp. (C.C.A.) 67 R (2d) 135."
[6,7] We come now to the question whether the Amco apparatus used by Swindell infringes plaintiff's reissue patent. The patent statutes do not define what constitutes infringement, but many judicial decisions have established the doctrine so that there is no uncertainty in the law as applicable to this case. To constitute infringement there must be identity of function and substantial identity of way in performing that function; or in slightly different wording, a device infringes "if it performs substantially the same function in substantially the same way to obtain the same result." Sanitary Refrigerator Co. v. Winters, 280 U.S. 30, 42, 50 S. Ct. 9, 13, 74 L. Ed. 147; Westinghouse v. Boyden Power-Brake Co., 170 U.S. 537, 18 S. Ct. 707, 42 L. Ed. 1136; Skelton v. Baldwin Tool Works (C.C.A. 4.) 58 F. (2d) 221; Hoeltke v. C. M. Kemp Mfg. Co. (C.C.A.4) 80 F. (2d) 912, 922; Oates v. Camp, 83 F. (2d) 111 (C.C.A.4). The flexibility of the rule depends upon the range of application given to the word "substantial." It is of permissibly broader scope in enforcing primary patents than where the latter are merely secondary, that is for improvements of a machine, as in the instant case. While any patent is entitled to "some range of equivalents" (Oates v. Camp, supra) "the range of equivalents depends upon and varies with the degree of invention" (Paper Bag Patent Cases, 210 U.S. 405, 415, 28 S. Ct. 748, 749, 52 L. Ed. 1122). As the claims in suit clearly do not mark any high degree of invention in view of the prior art, the patent in suit is not entitled to a broad range of equivalents, that is, the word "substantial" as here used is in this case to be strictly rather than broadly applied. Walker on Patents (6th Ed.) § 416, p. 510; Frick Co. v. Lindsay (C.C.A.4) 27 F.(2d) 59, 62.
Models of the competing apparatus have been offered in evidence. They are both movable lehrs of the modern unit type. Their exterior walls are both of sheet metal heavily insulated with rock wool. They are of substantially similar exterior appearance with the exception that he defendant's lehr is somewhat larger and wider. But the exterior structure is not involved in the patent claims and is of no particular significance in the case. The question as to infringement arises on the interior structure including the arrangement of the flues and the conveyor. belt. So far as the conveyor belt is concerned, that will be considered in connection with the Ingle patent. As to the flue arrangement, we find the only real similarity between the two structures to consist in the fact that both have a longitudinal lower flue beneath the lehr. The defendant’s structure, however, also has an upper flue of short length and it has separate burners for each flue. The striking difference in function, and operation of the defendant's apparatus as compared with the plaintiff’s results from the fact that it does not have the plaintiff’s feature of the dilution of the heated gases in the lower flue at spaced intervals by damper openings permitting the introduction of cool air into the heated flue. Defendant’s apparatus is, however, provided at spaced intervals with dampered uptakes from the flues whereby the heated gases can be let out through a manifold into the outer air. There are four of such outlets in structure, and the temperature control in the annealing stage of the lehr is effected by the opening or closing of the dampers whereby the intensity of heat at spaced intervals from the burners can be to some extent regulated by the manipulation of the several dampers. It is to be noted that the heated lower flue of the defendant's structure extends longitudinally only about two-thirds of the length of the lehr, the remaining one-third-being without positive heat control. The latter is the portion of the tunnel which the glassware traverses after leaving the annealing stage. Defendant’s structure contains no cold air flues of any kind but does have in the rear third of the lehr raisable openings in the top something like hinged trap doors, which further operate to permit the escape of the heated air, and in this way, by subtraction of heat, tend to lower the temperature in the rear end zone. The striking functional difference between the means employed by the plaintiff and by the defendant respectively to measurably control temperature within the lehr is that the plaintiff's apparatus functions in that respect by the introduction of cold air, while the defendants apparatus operates by the subtraction or escape of hot air.
As might be readily understood from general knowledge with regard to heating and cooling devices for various enclosures, house and others, and operation of stoves and furnaces, there is nothing new in the use of dampers to control the flow of heat. And it is not surprising, therefore, to find in the art of glass annealing that lehrs for many years’ have been provided in various ways with damper control of heated flues. We find this feature of temperature control, in many of the prior patents for lehr construction and referred to in printed publications. In general it may be said that the Amco lehr uses no method of heat control or regulation, as compared with the plaintiff's structure, and its patent claims, in suit, which was not known and old-in the art more than two years prior to the plaintiff's patent application.
In addition to the essential difference between the method of temperature control in the lehr between the two structures, there are numerous other structural differences between the two lehrs. These have been succinctly summarized by defendant's expert witness Schwartz as follows:
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7. In the opinion filed herewith the claims of the patents in suit are set out, analyzed and discussed with respect to the question of infringement thereof by the lehrs made by the Amsler-Morton Company and operated at the plant of the defendant, Swindell Bros., Incorporated, in Baltimore City.
8. The evidence establishes that prior to the patents in suit it was common practice to anneal glass in lehrs so-called; which, consist of a long, tunnel through which the articles to be annealed are passed on endless conveyors.
9. The evidence establishes that prior to the patents in suit it was common practice to heat such lehrs and to control the temperature, therein in a manner to subject the glass articles to a gradually decreasing temperature environment (termed in the art the temperature gradient) from the end where it is charged into the tunnel, to the discharge end thereof, wherein and whereby the articles are subjected to three distinct steps of heat treatment, the first, or high temperature step during which the articles are subjected to a temperature of about 1000 degrees F. being that at which all strain is removed from the glass; second, a slow and gradual cooling step during which the temperature of the glass is reduced from 1000 degrees F. to the critical point of about 750 degrees F., at which temperature no further strain is imposed upon the glass; and third, a rapid, or accelerated cooling to room temperature; the first and second steps are known in the art as the critical annealing range of the ware.
10. The evidence establishes that prior to the patents in suit it was common practice to provide for controlling the critical annealing range of the lehr tunnel by regulating the temperature of the tunnel longitudinally thereof by any one of combination of the following means, (a) controlling the heat loss by radiation by employing wall insulation of different thickness throughout the longitudinal extent of the tunnel walls, (b) by regulating the. application and intensity of the heat longitudinally of the tunnel, (c) by removing heat at intervals through damper-controlled openings longitudinally of the tunnel, (d) by removing the hot gases or the products of combustion from the heating flue, (e), by the application of a cooling medium externally of the tunnel, and (f) by the admission of cold air directly into the tunnel.
11. The evidence includes patents showing that prior to the patents in suit it had been proposed to control the temperature gradient throughout the critical annealing zone of the lehrs by various means, such as by varying the thickness of the wall insulation; by regulating the application and intensity of the heat longitudinally of the tunnel; by the use of dampered controls; and by removing heat at intervals from the tunnel through dampered control openings spaced longitudinally of the tunnel; by the removal of hot gases or the products of combustion from the heating flue as in the Milner patent No. 1,361,604 and others; by the application of cooling medium externally of the lehr tunnel (as by Fox ,No. 1,165,586); by the admission of air directly into the tunnel at the discharge end thereof and by the introduction of cold air into the tunnel from, beneath the tunnel as by Stenhouse No. 1,474,058.
12. The evidence also establishes that prior to the patents in suit various forms of endless belt conveyors were used to automatically transport the glassware through the tunnel which included perforated conveyors of various types which permitted free transference of heat through said conveyors, and various patents show or claim the use of woven wire conveyors or belts for various stages of glass annealing and in ovens for baking and japanning. Other Patents show tat it had been proposed to reheat the return strand of lehr conveyors by maintaining a heat relation between the ware-bearing and return strand in their passage through the tunnel.
13. Other patents in the prior art established that prior to the patents in suit it had been proposed to employ sheet metal walls with non-heat conducting insulating material for the lehr tunnel walls and that such construction had, been put into commercial use for glass lehrs and was in very common and general use for oven construction for baking and similar purposes.
14. The evidence also establishes that as early as 1920, so-called portable unit lehrs had been reduced to practice particularly by one Shackelford. (see his patent No. 1,642,790) and by Mayers (No. 1,338,240).
15. A prior patent, Gilman, No. 841,085, January 8, 1907, disclosed a conveyor drive mechanism for grain in which a wide flat conveyor is driven by a drum with which the conveyor is brought into intimate contact by means of an idle pinch roll which, in addition to producing tension on the conveyor, brings the conveyor in intimate contact with the maximum surface area of the driving drum which drum is in contact with the inner surface of the conveyor.
16. In the opinion filed herewith there further review of the history of the development and continuous course of improvement of the glass annealing lehrs and further Exposition of the prior art and its application. to the issue of infringement in this case:
17. In the opinion the structure and operation of Amsler-Morton's lehr as operated by Swindell the defendant is described and on application thereto of the claims in suit of the plaintiff's patents now relied on, there is found to be no infringement for the reasons stated in the opinion.
18. As no infringement is found, it is not considered necessary to make findings of fact or conclusions of law on the issue as to the validity of the claims in suit of the plaintiff's, patents.
19. As to the defense of laches, it is also unnecessary to make ultimate findings. The more important facts bearing on this defense are as follows: The original of the plaintiff's reissue patent issued, January 26, 1926 and the Ingle patent issued May 4, 1926. The lehr construction corresponding to ’the accused structure operated by Swindell was sold by the Amsler-Morton Company, the intervenor, about January 1, 1927. The plaintiff had at least very substantial knowledge thereof during 1928. The reissue application was patented April 9, 1929 and plaintiff formally notified the intervenor of infringement June 7, 1929. The intervenor denied infringement, and impliedly at least invited suit. No suit has yet been brought by the plaintiff directly against the intervenor and the first suit brought against the intervenors apparatus is the present suit against Swindell filed July 30, 1934. If material to the case I find the plaintiff's delay indirectly suing the intervenor has been unreasonably protracted and the explanations and excuses for the delay suggested by plaintiff are not impressive. But as to the defendant, Swindell, it will be noted that suit was brought in a little more than three years after plaintiff's knowledge of his use of the Amsler-Morton apparatus and the plaintiff furnishes a reasonable explanation for such delay, as occurred in the suit against Swindell, at least to the extent that the delay would not justify refusal of an injunction if the plaintiff were otherwise entitled thereto; however, the issue might be as to an accounting.
20. If material to the case, I find that the license and lease agreements under which the defendant Swindell obtained the right to use the Type D lehrs installed by the plaintiff, include a number of patents, the structures of which are not embodied in the accused lehrs and relate to subject matter not, employed by the defendant.
Conclusions of Law.
1. Plaintiff is the owner of the patents in suit, namely, Mulholland No. 1,840,463; Ingle No. 1,583,046 and Mulholland reissue No. 17,263.
2. No one of the Claims in issue of the Mulholland patent No. 1,840,463, namely, Nos. 1 to 5 inclusiye, is infringed by the use by the defendant of the Amsler-Morton lehr.
3. Claim, 5 in issue, of the Ingle patent No: 1,583,046, is not infringed by the use by the defendant of the Amsler-Morton lehr.
4. No one of the Claims in issue of the Mulholland reissue patent No. 17,263, namely Nos. 2, 7, 8, 44, 45, 48, 49, 50, 51, 52 and 53 is infringed by the use by the defendant of the Amsler-Morton lehr.
5. The defendant and intervenor are entitled to a decree for a dismissal of the plaintiff's bill of complaint in this case, with taxable court costs to be allowed to the defendant and the intervenor. [not finished]