Full opinion text
OPINION STEWART, District Judge: This is a suit for infringement of certain claims of a patent owned by plaintiff Dennison Manufacturing Company (“Dennison”), relating to clips of attachments as exemplified by the familiar molded plastic attachments used in retailing operations to affix tags to garments on display. The case was tried without a jury, and this opinion comprises the Court’s findings of fact and conclusions of law pursuant to Rule 52(a), F.R.Civ.P. THE PARTIES Dennison is a corporation of the State of Nevada, with a place of business in Framingham, Massachusetts. It owns the patent in suit by virtue of an assignment by the patentee, Gordon B. Lankton (“Lankton”). Defendant Ben Clements & Sons, Inc. (“Clements”) is a corporation of the State of New York, and at the time this suit was brought maintained a place of business in New York City. Clements imports and sells devices which allegedly infringe plaintiff’s patent. Jurisdiction and venue are not challenged. This is an action arising under the patent laws of the United States, 35 U.S.C. §§ 271 and 281, with jurisdiction based on 28 U.S.C. § 1338(a) and venue on 28 U.S.C. § 1400(b). 1. The Lankton Patent The Lankton U.S. Patent 3,733,657, issued May 22, 1973 on an application filed May 25, 1972, concerns a plurality of attachments, each of which is to be associated individually with an object by being inserted through that object. The attachments are formed into an easily handled assembly by being secured together not only at those ends which are to be inserted through the object, as in the prior art, but also at their opposite ends, thereby preventing the individual attachments from tangling while they remain part of the assembly or clip. The second connection, that is, the one between the ends of the attachments that do not pierce the object, is designed to be more readily frangible in torsion than in tension, to facilitate the separation of an attachment from the clip after the attachment has been associated with an object, leaving the remaining attachments secured to one another. Background Facts Although the claims of the patent in suit claim more broadly, Lanlcton’s original conception related to plastic molded attachments used in “marking” operations. In retail merchandising, it is often desirable- to mark objects, such as garments displayed on a rack, to convey information to the consumer such as brand name, price and size. Over the years, many different means have been devised for and used in marking operations, but for the purpose of attaching a tag to a garment displayed on a rack, the most widely used device has been some form of a “hang tag” which allows the tag to hang from the garment. At the time Lankton entered the picture in early 1972, Dennison was marketing (and still markets) a hang tag attachment known commercially as the “Swiftachment”, which was introduced in 1965. It consisted of a number of plastic attachments integrally molded into a clip or assembly. Each attachment was comprised of a “T-bar” (the end which was inserted through an object by means of a hollow needle), an elongated section or “string”, and at the opposite end of the string from the T-bar, an enlarged portion or “paddle”, which was designed to prevent the tag once attached from falling off .the string. Each attachment was joined at the T-bar end to a strip of plastic known as a “runner bar” by a sturdy connection which was designed to be cut by a blade within an attaching device, the entire assembly having been manufactured in a single molding operation. The paddle ends were not joined in any fashion. After being molded, the plastic assembly was stretched in order to impart strength and flexibility to the strings, a process which at first took place in the mold by moving the ends of the mold apart, and later, because of cost advantages, outside the mold in a separate stretching apparatus that grasped the ends of the attachments and pulled them in opposite directions. While out-of-the-mold stretching achieved production advantages over the previous method of in-the-mold stretching, it also presented a problem — often when a clip was ejected from the mold one or more of its strings or paddles would deviate from the parallel orientation in which it was molded, with the result that the stretching apparatus would fail to grasp that paddle, leaving the string unstretched. Clips with just one unstretched string were not being shipped by manufacturers to customers at the time of Lankton’s invention. Another, more serious problem, not particularly associated with out-of-the-mold stretching, was prevalent with the Swiftachment devices, as with its precursors— the stretched strings had a tendency to tangle with other strings on the same clip and with the strings of other clips when packed in a box for shipment. It was to this problem that Lankton’s invention specifically addressed itself. The specification of the patent in suit relates several objects of Lankton’s invention, which can be summarized as to provide a structural solution to the tangling problem. Analyzing the mechanics of a normal attaching operation utilizing the Swiftachment-type device, Lankton realized that if there existed a connection between the paddles of the attachments in a clip, that connection would be subjected to a combination of torsion and tension by the normal movements of the operator in attaching a tag to a garment. Thus, the structure Lankton devised was one that was designed to resist strong dislocative forces during manufacturing and handling, thus eliminating the tangling problem, but to break easily when twisted, in the course of an attaching operation. As indicated in the specification, Lankton thought the normal spacing between paddles, about 0.04 inch, militated against the attainment of a connection with the desired characteristics, so he devised a construction to shorten the distance, in effect'making the connection more torsion-sensitive. Lankton provided protrusions on the face of each paddle surface, with the result that the filamentary connection spanned only 0.005 inch and consequently readily yielded to torsion. Not all of the claims of the patent in suit, however, are limited to Lankton’s conception. In addition to the protrusion/short filament embodiment, there are claims which cover generally clips of attachments joined at or near both ends by connections which are severed at different times and by different means, one connection being more readily severable than the other. As Clements’ devices do not utilize the precise form of connection which Lankton conceived, the claims which defendant is accused of infringing are claims which are not limited to the protrusion/short filament embodiment. II. The Issues Defendant imports from Korea, Japan and Italy and sells in the United States plastic molded assemblies of attachments utilizing one or more thin filamentary connections between the paddles. These are the alleged infringing devices. Clements denies infringement and asserts that the claims in suit are invalid because they are indefinite, because they “overclaim”, and because they are obvious in light of the prior art. Even if the claims in suit are not invalid on any of these grounds, defendant argues, they may not be sued upon because they were obtained with deceptive intent. These are the issues to be decided in this opinion. In addition, defendant has filed a countersuit alleging patent misuse and antitrust violations, issues which have not yet been tried, and await the outcome of this suit. Damages are also reserved for later trial or accounting. III. The Claims in Suit The patent in suit contains 22 claims setting forth Lankton’s invention and variations thereon, as well as methods of manipulating the assemblies of attachments. Defendant has not been accused of infringing all of these claims, and there is a threshold question as to which claims are in suit. The Pre-Trial Order in this case listed as an issue to be tried whether the following claims are infringed by defendant: Claims 1, 2, 3, 4, 5, 7, 9, 10, 11, 14, 15, 16 and 17. However, in its Trial Brief and again in its Post-Trial Brief, plaintiff stated that it was confining its case “without prejudice” to proving infringement of Claims 1, 2, 4, 5, 7, 10, 11, 16 and 17, thus omitting Claims 3, 9, 14 and 15 from its proof. We therefore will make no determination of whether Claims 3, 9, 14 and 15 are infringed. But that does not end the matter. Defendant asserted in its answer to the complaint in this case the affirmative defense of invalidity of the claims in suit. Under Rule 8(c), F.R.Civ.P., we are required to treat a mistakenly designated defense as a counterclaim where justice so dictates. Applying this standard, and treating the affirmative defense of the claims’ invalidity as a properly designated counterclaim, we think defendant is entitled to an adjudication of whether all claims which it has been accused of infringing are valid, including those which plaintiff has chosen to omit from its proof. Since defendant arguably does infringe the omitted claims, there exists a genuine controversy as to the validity of the claims and that issue ought to be decided. Thus, we will consider the validity of all of the claims denominated in the Pre-Trial Order, which are set forth in full in the margin. Claims 1, 2, 3, 4, 5, 7, 9, 10 and 11 are article claims, describing the structure claimed in the patent in suit. Claim 1 is the independent claim upon which the remainder of the claims directly or indirectly depend, that is, they incorporate each and every limitation of Claim 1 and add further requirements or refinements. Claims 14, 15,16 and 17 are method claims, claiming as invention the methods of manipulating the assemblies of attachments. We consider first the validity of the claims in suit and then their infringement. IV. Presumption of Validity The validity of the claims in suit is strenuously challenged by defendant — if the claims in suit are invalid, they cannot be infringed. Clements asserts their invalidity on three grounds: indefiniteness (35 U.S.C. § 112), “overclaiming” (35 U.S.C. § 112), and obviousness (35 U.S.C. § 103). There is no attack on the novelty (35 U.S.C. § 102) of the claimed invention. 35 U.S.C. § 282 reads in relevant part: A patent shall be presumed valid. Each claim of a patent (whether in independent, dependent, or multiple dependent form) shall be presumed valid independently of the validity of other claims: dependent or multiple dependent claims shall be presumed valid even- though dependent upon an invalid claim. The burden of establishing invalidity of a patent or any claim thereof shall rest on the party asserting such invalidity. This statutory presumption of validity has no evidentiary weight but means that reasonable doubts will be resolved in favor of the patentee. Reeves Bros., Inc. v. U. S. Laminating Corp., 417 F.2d 869, 872 (2d Cir. 1969); Lorenz v. F. W. Woolworth Co., 305 F.2d 102, 105 (2d Cir. 1962); Lerner v. Child Guidance Products, Inc., 406 F.Supp. 560, 563-64 (S.D.N.Y.1975), aff’d, 547 F.2d 29 (2d Cir. 1976). Its effect on the burden of proof is that the patent holder is relieved of the burden of establishing the validity of the claims in suit as a requisite for the successful maintenance of an infringement action and the burden is placed instead on the alleged infringer who asserts the invalidity of the claims. Lorenz v. F. W. Woolworth Co., supra, 305 F.2d at 105. A preponderance of the evidence will satisfy the burden. Plastic Contact Lens Co. v. W. R. S. Contact Lens Labs, Inc., 330 F.Supp. 441, 443 (S.D.N.Y.1970); Thomson Industries, Inc. v. Nippon Thompson Co., 298 F.Supp. 466, 472 (E.D.N.Y.1968). These principles apply generally to our discussion of the validity of the claims in suit, to which we now turn. However, the presumption of validity will require further analysis in the context of defendant’s argument that the claims are invalid because of obviousness, infra. V. 35 U.S.C. § 112 Defendant argues two grounds on which the claims in suit are invalid under 35 U.S.C. § 112: indefiniteness and “over-claiming”. That section reads in pertinent part: The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention. The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. A. Indefiniteness Defendant asserts that the claims in suit fail to satisfy the specificity requirement of § 112 in three ways. It is argued first that the claims contain impermissible “terms of relativity”; second, that the terms of the claims are vague and indefinite; and third, that the claims do not define the nature of the inner-paddle connection or the method of severing it with sufficient specificity. Plaintiff responds that the claims are clear and definite and that defendant distorts the claim language. Plaintiff urges the conclusion that the claim language is meaningful and understandable to those skilled in the art. To be patentable “[a]n invention must be capable of accurate definition, and it must be accurately defined . . . .” United Carbon Co. v. Binney & Smith Co., 317 U.S. 228, 237, 63 S.Ct. 165, 170, 87 L.Ed. 232 (1942). The specificity required by § 112 advances two objectives: [F]irst, that in return for the grant of a patent monopoly the patentee must make sufficient disclosure to enable one skilled in the art to reconstruct the invention; and, second, that the patentee describe his invention with sufficient definiteness to enable others to discern the boundaries beyond which experimentation and invention are undertaken at the risk of infringement. Norton Co. v. Bendix Corp., 449 F.2d 553, 555 (2d Cir. 1971). In consonance with these objectives, absolute precision in the claim language is not required; it is enough “[i]f the claims, read in the light of the specifications, reasonably apprise those skilled in the art both of the utilization and scope of the invention, and if the language is as precise as the subject matter permits . .” Georgia-Pacific Corp. v. United States Plywood Corp., 258 F.2d 124, 136 (2d Cir.), cert. denied, 358 U.S. 884, 79 S.Ct. 124, 3 L.Ed.2d 112 (1958). Defendant argues, incorrectly, that we may not resort to the specification to determine the meaning of terms in the claims. “[I]t is fundamental that claims are to be construed in the light of the specifications and both are to be read with a view to ascertaining the invention . . . .” United States v. Adams, 383 U.S. 39, 49, 86 S.Ct. 708, 713, 15 L.Ed.2d 572 (1966). While the specification may not expand or limit the patent monopoly, which is measured by the claims, Great Atlantic & Pacific Tea Co. v. Supermarket Equipment Corp., 340 U.S. 147, 149, 71 S.Ct. 127, 95 L.Ed. 162 (1950), rehearing denied, 340 U.S. 918, 71 S.Ct. 349, 95 L.Ed. 663 (1951), it is entirely appropriate to resort to the specification for the purpose of understanding patent claims that are complex, unclear, or ambiguous. Maclaren v. B-I-W Group Inc., 535 F.2d 1367, 1372-73 (2d Cir.), cert. denied, 429 U.S. 1001, 97 S.Ct. 531, 50 L.Ed.2d 612 (1976). With these principles in mind, we turn to defendant’s arguments that the claims are invalid for lack of specificity. First, Clements contends that the claims in suit utilize “terms of relativity” which are impermissible in that they evade precise definition. The terms which defendant cites as objectionable are found in Claim 1 (“comparatively more readily sever-able”), Claims 3 and 9 (“more readily sever-able in torsion than in tension”), and Claims 4 and 10 (“substantially greater resistance to breaking when tensioned than when twisted”). Defendant relies on Long Mfg. Co. v. Lilliston Implement Co., 328 F.Supp. 268, 276 (E.D.N.C.1971), aff’d per curiam, 457 F.2d 1317 (4th Cir.), cert. denied, 409 U.S. 874, 93 S.Ct. 119, 34 L.Ed.2d 126 (1972), in which the court held invalid for indefiniteness a patent on a threshing machine because it used terms such as “relatively large” when describing one of the threshing cylinders and “relatively low” when referring to the height of the combine, without supplying in the claims or specification any dimensions or bases for comparison. The claims before us, however, are markedly different from those in Long, in that bases for comparison are provided within the language of the claims themselves. In Claim 1, the severability of the second connection, the “securing means”, is compared to that of the “frangible means” joining the T-bar end to the runner bar. In Claims 3 and 9, the characteristics of the connection under tension are compared to its characteristics when subjected to torsional forces; and the effect on the paddle connection of tension and twisting forces are contrasted in Claims 4 and 10. We have no difficulty understanding these claims, and they should not present a problem to one skilled in the art, particularly when read in the light of the specification and drawings. Next, defendant argues that the word “twisted”, found in Claims 4 and 10, is vague and indefinite, as evidenced by the fact that its meaning was disputed by defendant’s and plaintiff’s experts. Defendant adduced testimony that “twist”, as used in these claims, meant rotation in a single plane and that the connections claimed in the patent in suit were intended to break upon the application of rotation alone; or, alternatively, that they were intended to be broken by the sequential rather than simultaneous application of torsion and tension. Plaintiff argued that Lankton’s meaning of “twist” included a slight pull or a corkscrew motion. The existence of a conflict over the possible meaning of terms in a claim does not require the conclusion that the claim is indefinite. We think it clear when the claims, specifications and drawings are read together that “twist” was meant to and does include a pulling motion in addition to rotation. Defendant challenges the specificity of the language in Claims 1,14 and 16 that the paddle connection is designed to be and is broken “externally of an attaching device.” With respect to Claim 1, when this language is read in its context and in light of the specification and drawings, it is evident that the paddle connection is intended to be severed while the clip of attachments remains in the gun. The “comparatively more readily severable” connection is broken as part of a normal attaching operation, in which the leading attachment is “twisted off from the clip.” Col. 4, line 32; see Figures 3 and 4. No separate action is required on the part of the operator, other than the “continuous movement which is part of a normal attaching operation.” Col. 3, lines 42-46; see also Col. 6, lines 15-17. Thus, in the context of Claim 1, rather than meaning that the connections between the paddles are severed after the clip is removed from the gun, “externally of said attaching device” is more appropriately interpreted as contrasting the means of severing the paddle connection to the means of severing the T-bar connection, which is severed in and “by means of an attaching device.” With respect to Claims 14 and 16, plaintiff concedes that the “externally of an attaching device” language found in these claims yields the meaning ascribed to it in Claim 1 as well as the additional meaning urged by defendant — that the connections are severed after the clip is removed from the gun, as in the “batch” embodiment described in Col. 8, lines 26-36. We think that Claims 14 and 16 may be read to describe both embodiments, and that the significance and meaning of “externally of an attaching device” is not thereby diminished. In both embodiments, the T-bar connection is broken by means of a blade in the attaching device which is activated when the operator “pulls the trigger” of the gun. Immediately after the T-bar connection has been severed, the T-bar is pushed through the needle of the attaching device, attaching the leading attachment to an object. In the case of the embodiment of Figures 1— 13, the paddle connection is then severed by the operator’s pulling the gun, still containing the clip of attachments, away from the leading attachment. It is severed “externally” of the gun in that, unlike the T-bar connection, no blade or other mechanism within the attaching device effects the separation, which occurs outside of the device. This meaning is clearly set forth in the specification and drawings. In different fashion, but nonetheless externally of the attaching device, the paddle connection in the batch embodiment is severed by a knife or scissors, after the clip has been removed from the gun. This meaning, too, is clearly set forth in the specification. Thus, the claim language that the connection is broken “externally of an attaching device” is not indefinite or insufficiently specific. That the language reads broadly does not serve to invalidate the claims so long as its meanings are clear in light of the specification and drawings, as they are here. In addition to attacking the specificity of particular phrases of the claims, defendant assails the article and method claims in suit for failing to define the nature of the paddle connection and the method of severing it. This defect in the broader claims, such as Claims 1,14 and 16, defendant argues, is not cured by the narrower claims, which either simply locate the connection or are themselves vague and indefinite, and thus must also be adjudged invalid. Claim 1 defines the “securing means”, or paddle connection, as “being comparatively more readily severable than [the T-bar connection] and adapted to be severed externally of an attaching device.” Defendant argues that the “comparatively more readily severable” portion of this definition is vague and indefinite, so much so that a paddle connection which is a miniscule degree smaller and weaker than the T-bar connection and which cannot be severed except by means of a knife or scissors would fall within the definition. This interpretation ignores the limitation contained in the claim that the paddle connection be “adapted to be severed externally of” the attaching device. This limitation, which was added to the claim by amendment after rejection because of obviousness, when read in the light of the specification and drawings, excludes from the scope of the claim defendant’s suggested interpretation. The references in the specification which describe how the connection defined in Claim 1 is to be broken best illustrate the meaning of the limitation. The leading attachment is separated by being twisted off from the remaining attachments in the clip. This twisting force is applied as part of a normal attaching operation, requiring no separate action on the part of the operator. Col. 2, lines 49-52, 65; Col. 3, lines 2,13-17, 40-45. [E]ach attachment as it is individually used may readily be separated from the clip without requiring any separate action on the part of the operator other than a continuous movement which is part of a normal attaching operation in any event. Col. 3, lines 40-45. Thus, the connection is broken by the motion of pulling the attaching gun away from the leading attachment which has been fastened to an object (See Figures 3 and 4 and their description in the specification, Col. 4, lines 25 — 34); and the clear meaning of the “adapted to be severed externally” language is that the structure of the paddle connection is such that it can be broken as described in the specification. It would be inconsistent with this language as clarified by the specification to say that it includes a connection that is to be severed by a knife or scissors. Defendant’s argument that Claim 1 fails adequately to define the paddle connection is an exercise in selective reading of the claim. Maurice A. Crews, an expert witness produced by defendant, expressed his opinion that the claim was vague as to the paddle connection, but failed to read the claim in its entirety. The claim states that the paddle connection is “comparatively more readily severable than [the T-bar connection] and adapted to be severed externally of an attaching device” (emphasis added), but Crews refused to read these phrases of the claim together, let alone read them with the specification and drawings. Tr. at 2771-72, 2823, 3111-12. We conclude that defendant has not met .its burden of proving that Claim 1 is invalid for failure to define the paddle connection. It is defined sufficiently well to apprise one skilled in the art of the scope and utilization of the invention, and that is all that is required. Georgia-Pacific Corp. v. United States Plywood Corp., supra, 258 F.2d at 136. The argument is made that while Claims 2, 5, 7 and 11 specify the location of the second connection, they are of no assistance in further defining the connection. Given our finding that Claim 1, when read in the light of the specification and drawings, defines the nature of the connection with sufficient specificity to satisfy the requirements of 35 U.S.C. § 112, we find nothing objectionable in Claims 2, 5, 7 and 11. Claims 3 and 9 define the second connection as being “more readily severable in torsion than in tension”. Claim 3 is dependent upon Claim 2, which places the connection defined in Claim 1 “between and connected to” the paddles, while Claim 9 depends directly upon Claim 1, and thus does not contain the Claim 2 limitation. Defendant argues that the meaning of “more readily severable in torsion then in tension” is “mysterious”, Tr. 2780, vague and indefinite. Claims 3 and 9, on their face, are not definitive as to the nature of the connection, but resort to the specification yields a clear understanding of what is required of the connection and how it is intended to function. It is an object of the invention to design a connection that would remain intact during manufacturing and handling, where it would be subjected to tension and shear forces, but that would break easily as part of the normal attaching operation, where it would be twisted off from the clip, that is, subjected to torsional forces. Col. 2, lines 39-48. The significance of the differentiation between torsion and tension is, thus, apparent in the specification, and these claims adequately detail the relationship between the two. Claims 4 and 10 define the paddle connection as comprising “a short, narrow length of material and dimensions such as to have a substantially greater resistance to breaking when tensioned than when twisted.” Claim 4 is dependent upon and incorporates the limitation of Claim 2, while Claim 10 depends directly upon Claim 1. Defendant admits that Claims 4 and 10 further define the nature of the connection, but contends that they nevertheless are vague and indefinite. Tr. 2337, 2782-84. We disagree. Although the claims do not specify how short and narrow the connection must be, the specification defines the properties of the connection, describes how it is to perform, and even sets forth Lank-ton’s “best mode”, 35 U.S.C. § 112, giving the exact dimensions of the connection favored by Lankton. When read in the light of the specification and drawings, the meaning of “short” and “narrow” would be readily apparent to one skilled in the art. Thus, we find that the article claims in suit are not invalid for failure to particularly point out and distinctly claim the subject matter of the invention. We turn our attention next to the method claims and consider whether each of these meets the specificity requirements of 35 U.S.C. § 112. Defendant attacks Claims 14 and 16 on the grounds that they “merely recite the sequence of severing and that the second connection is severed outside of the attaching device. Undefined are the nature of the connection and the method of severing same, essential limitations in these claims.” Defendant’s Post-Trial Brief, 16. That the method claims fail to define the nature of the connection is no shortcoming. A process or method is patentable in and of itself, 35 U.S.C. §§ 100(b) and 101, there being no requirement that a structure be disclosed in a method claim. As to the argument that Claims 14 and 16 are unspecific in that they fail to specify when and how the paddle connection is severed, resort to the specification provides the necessary definiteness. As we noted above, both the device of Figures 1-13 and that of Col. 8, lines 26-36, the batch embodiment, are 'encompassed by the language of Claims 14 and 16. And, as we also noted above, the fact that these claims can be interpreted to encompass both devices and methods of severing their connections does not invalidate the claims, as long as both are defined with the requisite specificity, as they are here. Nor are Claims 15 and 17 indefinite. Defendant argues that they suffer the same infirmity as Claims 14 and 16, the claims upon which they respectively depend; that is, that they do not specify how or when the second connection is to be broken and include within their scope the batch embodiment. We disagree that these claims encompass the batch embodiment. Claims 15 and 17 accomplish the separation of the leading attachment from the clip “by rotating said attachment relative to said clip, thereby . . . exertpng] a substantial torsional force” on the paddle connection. In the batch embodiment, the paddle connection is “highly strain-resistant” and is broken “by cutting it with a knife or scissors.” Col. 8, lines 26-36. Thus Claims 15 and 17 do not read on the batch embodiment but are confined to the devices depicted in Figures 1-13, in which the leading attachment is separated from the clip by rotating it relative to the clip as part of a normal attaching operation. For the foregoing reasons, we conclude that none of the claims in suit are invalid for failure to point out and distinctly claim the subject matter of Lankton’s invention. B. “ Overclaiming ” Because the claims in suit omit the critical limitations required to define Lankton’s invention, defendant argues, they encompass not only his invention but vast areas of the art not properly a part of the patentee’s monopoly. These omissions, it is argued, invalidate the claims because they fail to comply with the mandate of 35 U.S.C. § 112 that: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Since Lankton’s conception was limited to the short filament/protrusion embodiment of Col. 6, lines 18-36, defendant contends that the claims in suit, none of which are so limited, are invalid because they do not claim “the subject matter which the applicant regards as his invention.” None of the authorities cited by defendant supports this argument. Over-claiming is properly asserted as a defense when the claims include by their breadth “that which is conceded to have been known in the prior art — that which the prior art anticipated or made obvious.” Wayne Knitting Mills v. Russell Hosiery Mills, Inc., 400 F.2d 964, 968 (4th Cir. 1968), cert. denied, 393 U.S. 1064, 89 S.Ct. 717, 21 L.Ed.2d 707 (1969); accord, Wilcox Mfg. Co. v. Eastern Gas & Fuel Associates, 400 F.2d 960, 964 (4th Cir. 1968), cert. denied, 393 U.S. 1051, 89 S.Ct. 691, 21 L.Ed.2d 693 (1969); see Jamesbury Corp. v. Litton Industrial Products, Inc., 586 F.2d 917 (2d Cir. 1978). Defendant does not argue that the claims in suit were anticipated by the prior art, and the issue of obviousness is one which we shall discuss in great detail, infra. It has also been recognized as a defense where the claims were not limited to a structure essential to accomplish the advantage claimed for the invention. Murton v. Ladd, 122 U.S.App.D.C. 274, 276, 352 F.2d 942, 944 (1965). But that is not the situation here, for we find that the claims in suit disclose and are limited to a structure which is essential to carry out the advantages set forth in the specification and drawings. That they vary from Lankton’s actual conception of the structure necessary to accomplish the results he envisioned does not detract from their validity. Claims will almost always be broader than the inventor’s own conception as revealed in the specification and drawings, since he is only required to set forth the “best mode”, 35 U.S.C. § 112, of carrying out the invention. American Photocopy Equipment Co. v. Rovico, Inc., 257 F.Supp. 192, 196 (N.D.Ill.1966), aff’d, 384 F.2d 813 (7th Cir. 1967), cert. denied, 390 U.S. 945, 88 S.Ct. 1030, 19 L.Ed.2d 1133 (1968). The breadth of the claims does not itself cause their invalidity — it merely enhances the risk that the claims will be anticipated or made obvious by the prior art. Id. VI. Obviousness The pivotal issue in this lawsuit is that the claims in suit are invalid because they are obvious in light of the prior art. Before turning to an analysis of the prior art and its teachings, it is appropriate to set forth as background some principles of law which pertain to that analysis. As we stated above, a patent is presumed valid, and the burden of proof rests on one who asserts its invalidity. 35 U.S.C. § 282; e. g., Lorenz v. F. W. Woolworth Co., supra, 305 F.2d at 105. However, the patent in suit, being a combination of old and known elements relying for its patentability on the assertedly new and different function produced by the combination, should be subjected to more careful scrutiny than a patent which introduces novel elements into the art. Courts should scrutinize combination patent claims with a care proportioned to the difficulty and improbability of finding invention in an assembly of old elements. The function of a patent is to add to the sum of useful knowledge. Patents cannot be sustained when, on the contrary, their effect is to subtract from former resources freely available to skilled artisans. A patent for a combination which only unites old elements with no change in their respective functions obviously withdraws what already is known into the field of its monopoly and diminishes the resources available to skillful men. Great Atlantic & Pacific Tea Co. v. Supermarket Equipment Corp., supra, 340 U.S. at 152-53, 71 S.Ct. at 130; accord, Sakraida v. Ag Pro, Inc., 425 U.S. 273, 281, 96 S.Ct. 1532, 47 L.Ed.2d 784 (1976); Anderson’s- Black Rock, Inc. v. Pavement Salvage Co., Inc., 396 U.S. 57, 60-61, 90 S.Ct. 305, 24 L.Ed.2d 258 (1969); Julie Research Laboratories, Inc. v. Guildline Instruments, Inc., 501 F.2d 1131, 1136 (2d Cir. 1974). In addition to this caveat, defendant urges that the presumption of validity of the claims in suit is weakened or negated by the fact that the Patent Office did not have before it all the pertinent prior art when it examined Lankton’s application. While it is true that the failure on the part of an applicant to bring to the attention of the Patent Office pertinent prior art may weaken the presumption of validity of the claims, to have that effect the omitted prior art must be more than merely cumulative. Julie Research Laboratories, Inc. v. Guildline Instruments, Inc., supra, 501 F.2d at 1136 (“significant” prior art not before patent examiner); Reeves Brothers, Inc. v. U. S. Laminating Corp., supra, 417 F.2d at 871 — 72 (“certain relevant prior patents”, which essentially disclosed applicant’s invention, were not cited to Patent Office); Lerner v. Child Guidance Products, Inc., supra, 406 F.Supp. at 563 (strength of the presumption depends on whether the Patent Office had before it “the most relevant prior art”); Kahn v. Dynamics Corporation of America, 367 F.Supp. 63, 67 (S.D.N.Y. 1973), aff’d, 508 F.2d 939 (2d Cir.), cert. denied, 421 U.S. 930, 95 S.Ct. 1657, 44 L.Ed.2d 88 (1975) (“applicable prior art” was not before the Patent Office, as applicant had misrepresented the teachings of a prior patent over which applicant’s invention had to define in order to be patentable). Here, as will be evident from our discussion of the prior art, the patent examiner had before him prior art no less relevant to the claims of the patent in suit than the references cited to us by defendant. The presumption of validity, therefore, remains intact and is, in fact, strengthened. Lerner v. Child Guidance Products, Inc., supra, 406 F.Supp. at 563. A. The “John Deere” Inquiry Although the ultimate question of patent validity is one of law, Graham v. John Deere Co., 383 U.S. 1, 17, 86 S.Ct. 684, 15 L.Ed.2d 545 (1966), the obviousness or non-obviousness of the subject matter is to be determined against a factual background. Under § 103, the scope and content of the prior art are to be determined; differences between the prior art and the claims at issue are to be ascertained; and the level of ordinary skill in the pertinent art resolved. Id. As evidence of obviousness, defendant presented prior patents as well as the testimony of its two expert witnesses. The first, Harvey W. Samo, a mechanical engineer with some study in and a great deal of practical experience with plastic molding technology, testified to the obviousness of Lankton’s invention in light of the prior patents and the plastic molding art in general. Defendant’s second expert was Maurice A. Crews, a “largely retired” patent attorney who had been employed at one time by the Patent Office and who, by his own admission, had practically no experience in the marking field, Tr. at 2693, no experience in plastic molding, Tr. at 2694, and no contact other than in connection with this lawsuit with the guns and attachments in issue. Tr. at 2694. Mr. Crews’ particular expertise with respect to this lawsuit consisted almost entirely of that garnered from his study of the patent in suit and of the prior art references pertinent to this litigation. Tr. at 2694. A large portion of his testimony was an interpretation of the claims of the patent in suit in connection with defendant’s indefiniteness argument, and, despite his lack of familiarity with the plastic molding and attaching arts, a discussion of modifications of the prior patents that might be made by one skilled in the art. Plaintiff’s expert, Michael Rabins, a mechanical engineer and chairman of the department of mechanical engineering at Wayne State University, possessed academic expertise in the fields of statics, strength of materials, kinematics and machine design. His qualifications also included experience as a consultant and expert witness in a previous trial involving the attaching field, and consulting work for toy companies involving plastic, plastic molding and the behavior of plastic parts. Tr. 1325-26. Professor Rabins’ testimony was concerned mostly with the infringement issue, but he also commented on the prior art. On the question of obviousness, therefore, the most relevant, credible and significant evidence is the prior art publications, and the testimony of Samo and, to a lesser extent because of his lack of specialized knowledge of the plastic molding and attaching arts, Rabins. Scope and Content of the Prior Art Scope The parties dispute the scope and content of the pertinent prior art. Plaintiff has taken somewhat inconsistent positions with respect to the prior art against which the claims of the patent in suit are to be measured. In prosecuting this patent, the applicant took a limited view of the scope of the prior art. Each and every reference cited to the patent examiner was drawn from the tag or tag-attaching art (the Schumm patent, infra, was independently cited by the examiner). In its Trial Brief, at 69, plaintiff suggests that the relevant prior art “is that of molded plastic attaching devices of the type exemplified by Super Swiftachments,” a narrow view but one claimed to be “strictly commensurate with the claim language”. In its Post-Trial Brief, at 53, plaintiff repeats its assertion that its view of the relevant prior art is “strictly commensurate with the claim language” but fails to say what its view is of the prior art. Finally, in its Reply Brief, at 24, plaintiff seemingly retreats from its earlier position and states simply that “a flexible plastic special purpose attachment is not a rigid nail,” arguing that the Keck patent, infra, should not be considered prior art because of the different considerations applicable to rigid nails as opposed to flexible plastic attachments. Defendant has consistently argued that the pertinent prior art should be “the plastic molding art and the attaching or fastening art.” Post-Trial Brief, 25. For the reasons that follow, we agree with defendant’s position. In Digitronics Corp. v. New York Racing Ass’n, Inc., 553 F.2d 740 (2d Cir.), cert. denied, 434 U.S. 860, 98 S.Ct. 187, 54 L.Ed.2d 133 (1977), the court considered as relevant prior art the data processing art in general rather than data processing as applied to the totalisator art, relying on Dann v. Johnston, 425 U.S. 219, 96 S.Ct. 1393, 47 L.Ed.2d 692 (1976) (a case very similar to Digitronics on its facts — Court applied as prior art computer technology generally rather than computer technology in the banking industry). The court stated: In determining the scope of the relevant prior art with which the hypothetical ordinarily skilled person must be presumed to be familiar, we hold simply that the court must look, in light of . both the training of the patentee and the elements in the claimed invention which give it its novel quality, at what arts the patentee could reasonably be expected to consult in doing the inventing. Digitronics Corp. v. New York Racing Ass’n, Inc., supra, 553 F.2d at 745. The first consideration, the training of the patentee, presents no difficulty. Lankton’s academic training was as a mechanical engineer and his professional experience up to the time of his testimony in this trial consisted of twenty or more years in the plastic molding field, involving the manufacture of a wide variety of products. Tr. at 892-93. Moreover, his familiarity with the plastic molding field covers the full range of thermoplastic materials. Tr. at 894. Therefore, Lankton could reasonably be expected to consult the entire plastic molding art in devising his invention. The second consideration, the elements of the invention which give it its claimed novel quality, requires that we also look to the claims to determine the scope of the pertinent prior art. It is the “claims which define the boundaries of a patent monopoly.” Great Atlantic & Pacific Tea Co. v. Supermarket Equipment Corp., supra, 340 U.S. at 149, 71 S.Ct. at 129; Maclaren v. B-I-W Group Inc., supra, 535 F.2d at 1372. Since by the granting of a patent a patentee is granted a monopoly as broad as his claims may reach, “[i]t is but an evenhanded application to require that those persons granted the benefit of a patent monopoly be charged with an awareness”, Deere, supra, 383 U.S. at 19, 86 S.Ct. at 695, of the applicable art. The breadth of the claims, therefore, in part determines the scope of the prior art. Maclaren v. B-I-W Group Inc., supra, 535 F.2d at 1376. Claim 1 of the patent in suit is not limited to “molded plastic attaching devices of the type exemplified by Super Swiftachments,” or to “flexible plastic special purpose attachment^],” definitions of the relevant prior art alternatively offered by plaintiff, but is a broad claim describing “a clip of a plurality of attached-together attachments.” This claim is easily broad enough to include within its scope the Keck device whose claims describe “an assemblage of collated fasteners” as well as many other devices in the attaching or fastening art. The same may be said of the remainder of the article claims in suit, which depend directly or indirectly upon Claim 1, and of the method claims in suit. Further, although the specification refers to attaching devices molded of thermoplastic material, none of the claims in suit is limited to molded plastic attaching devices or to flexible plastic special purpose attachments; rather, each claim relates to attachments or clips of attachments in general without specifying the materials from which the attachments are to be fashioned. The breadth of the claims appears to be a result not of oversight, but of intention. While Lankton’s application as originally submitted for Patent Office consideration contained dependent claims (Claims 14-20) which specified clips “constituted by a one-piece assembly of molded plastic material,” Defendant’s Exhibit A, the amended claims omit any reference to materials. From this, it seems evident that the claims in suit, which are not so limited, were intended from the start to encompass within their scope “clip[s] of a plurality of attached-together attachments,” regardless of their material composition. Therefore, plaintiff may not now limit the relevant prior art to plastic molded attaching devices. See Maclaren v. B-I-W Group Inc., supra, 535 F.2d at 1373. Rather, the scope of the relevant art, as defined by the claims in suit, should include, as defendant suggests, the attaching or fastening art in general. See Deere, supra, 383 U.S. at 19, 86 S.Ct. 684. Having determined that the relevant pri- or arts include both the plastic molding art and the attaching or fastening arts, we now turn to the question of the content of those arts as they relate to the claims in suit. Content In determining the content of the prior arts which are relevant to the claims in suit, we consider those prior art references cited by the patent examiner in granting the patent in suit, those additional references cited by plaintiff in the application which were not cited by the examiner, and the patents and prior art cited by defendant which were not before the examiner. In prosecuting its application for the patent in suit, plaintiff applied for and was granted special status, subjecting the application to accelerated examination. In fulfilment of the applicant’s obligation under the accelerated examination procedure to make a detailed disclosure of prior art references, plaintiff listed eleven prior patents. In rejecting as obvious nineteen of the twenty-four claims of plaintiff’s application (and objecting to the remaining five as dependent upon the obvious claims), the patent examiner cited a twelfth prior patent. We begin by analyzing the disclosures contained in these twelve patents and then proceed to examine the eight prior art references (seven U.S. patents and one Japanese Utility Model Publication) cited by defendant that were not brought to the attention of or cited by the patent examiner. First, we consider the three patents cited by the patent examiner in allowing the claims of the patent in suit: Bone 3,103,666, Schumm 3,147,522 and Flood 2,825,162. Bone 3,103,666, patented September 17, 1963 and assigned to Dennison, is entitled Tag Attaching Apparatus and relates to “bar-lock” tag attachments. The bar-lock attachments with which Bone’s apparatus, or gun, is to be used are integrally molded in a strip of plastic material, each bar-lock consisting of a bar, a button and a filament joining the two. The bars are joined to a runner bar, forming a clip which is fed through Bone’s gun. The specification of the Bone patent mentions that previous attachments, namely the “bar-string-button” devices, with their string filaments, were susceptible to tangling and could not conveniently be attached by use of an automatic device. The improved plastic-molded bar-lock device lent itself easily to use in an automatic attaching device, the subject of Bone’s patent, and impliedly eliminated the tangling problem. Schumm 3,147,522, patented September 8, 1964 and entitled Flexible Tie, discloses a tightening device designed to be drawn in the form of a loop about an article such as the open end of a bag. The devices are molded parallel to one another and “connected by a plurality of narrow connecting portions integral with the enlarged end portions, which connecting portions may be easily severed to provide thus for a plurality of separate strips.” The advantage obtained by connecting the devices one to another is that the clip of fasteners may be fed into “a packing, machine in which the connecting portions . may be severed and in which each of the thus severed strips may automatically be formed into a loop and tightened about an end portion of a filled bag to close the same. . . . ” Thus, Schumm teaches a clip of fasteners, each of which is joined to its adjacent fasteners at each end by narrow connecting portions, which results in its suitability for use in conjunction with an automatic packaging machine. Both connections are severed in the machine. Flood 2,825,162, patented March 4, 1958, assigned to Dennison and denominated String Tag Attachment Device, discloses a loop of string with a bar receiving the ends of the loop and a button affixed at the loop’s midpoint. “The devices are grouped together in a row with the bars in parallel juxtaposition and a strip o*f material extending along the row, the strip being temporarily joined to each device of the group with adhesive which holds the group together but which permits the devices to be detached individually.” The strip, whose purpose as disclosed in the patent is to permit convenient dispensing, preferably is joined to the string of each device, but may instead be secured to the bars. The patent teaches that the bar of the leading attachment may be placed in the needle before the leading attachment is peeled away from the adhesive strip. In addition to these patents which were cited by the examiner, the specification of the patent in suit refers to two prior art patents: Bone 3,444,597 and Kirk 3,380,122. Bone 3,444,597, patented May 20, 1969, assigned to Dennison and entitled Filament Type Attachment, teaches a one-piece, molded plastic attachment device which claims to improve upon the devices to which Bone 3,103,666, relates (the molded plastic bar-lock devices) by stretching the portion which connects the bar and the button (the string), thus adding flexibility and strength to the string portion. In its preferred form, “. . . a plurality of the devices are molded together, the devices being connected by a rod . . . integrally joined to the cross-bars by necks . . . .” Bone 3,444,597 discloses the Dennison Swiftachment device, a clip of attachments with stretched strings, each attachment being connected at one point to a runner bar "by a neck that is designed to be severed in a machine or apparatus. The patent was disclaimed and dedicated to the public on October 24, 1970. Kirk 3,380,122, also assigned to Dennison, was patented April 30, 1968. Entitled Mold for Making an Attachment Device, the patented device is intended to perform the stretching of the strings of the molded devices of Bone 3,103,666. The patent recites that “[preferably a plurality of the devices are molded together, the devices being connected by a rod . . . integrally joined to the cross-bars by necks. . . . [Pjreferably the devices are left interconnected in groups until they are used and are then severed successively as needed.” The following seven patents complete the list of those cited to the examiner by Dennison in its application and statement in support of special status, resulting in the accelerated examination referred to above: Kohnle 1,416,665, Kohnle 2,112,627, Flood 2,915,177, Marshall 2,937,464, Tamaccio 2,950,555, Marshall et al. 2,987,840 and Rieger et al. 3,273,705. The two Kohnle patents, Marshall 2,937,464 and Tamaccio require little discussion. They disclose paper tags manufactured in strip form, each tag to be separated from the strip in a machine. Tamaccio is perhaps the most relevant of these four patents in that the material joining each tag is slightly weakened by crenelation or perforation to allow easy separation. Marshall et al. 2,987,840 also discloses tags in strip form, but joins each tag to its neighbors by thin portions of the tag strip material at the top and bottom of each tag. Flood 2,915,177 is a continuation-in-part of Flood 2,825,162, cited by the examiner, and adds nothing of substance. Finally, Rieger et al. 3,273,705, Fastener, patented September 20, 1966, discloses an integrally molded plastic fastener with a needle at one end and an eyelet at the other. It is intended to be used either manually or with a gun. The attachments are assembled in clip form, with thin connections between the needles that are easily severed as the needle is projected out of the gun. While it is certainly more relevant as prior art than the six patents discussed immediately before it, it is not as relevant as Bone 3,103,666, cited by the examiner. Thus, of these twelve patents (the eleven cited by plaintiff in its application for accelerated examination plus Schumm) we need consider only those cited by the examiner in allowing the claims of the patent in suit, for the remaining references are merely cumulative with the Bone, Schumm and Flood patents cited. The prior art references cited by defendant which neither the Patent Office nor plaintiff cited are: Spinner 2,435,561, Paxton 3,164,250, Spinney 3,285,404, Powers 3,348,669, Hauck 3,492,907, Keck 3,756,391, Rieger 3,185,367 and Japanese Utility Model Publication 45/1970-30363 (“JUMP”). Spinner, Paxton, Spinney, Powers and Hauck are cited by defendant in support of its statement that “[t]he prior art is replete with examples of the connection of a series of devices in a parallel array by connecting the devices at both ends thereof.” Defendant’s Proposed Finding No. 68. These five patents cumulatively disclose integrally-molded structures of plastic material having more than one thin, easily severable connection between the individual units in the assembly. In each of the patents, both connections are of the same strength and are severed simultaneously. Clearly, none of these patents adds anything to Schumm’s plastic fasteners, which are “connected by a plurality of narrow connecting portions integral with the enlarged end portions, which connecting portions may be easily severed to provide thus for a plurality of separate strips.” Rieger 3,185,367 teaches a fastener gun which is intended for use in conjunction with the barbed needle/eyelet type of device disclosed in Rieger et al. 3,273,705, cited to the examiner by plaintiff. Thus, it adds nothing to our inquiry. This brings us to the linchpins of defendant’s argument that the claims of the patent in suit are invalid because they are obvious: Keck and JUMP. Keck 3,756,391, Fastener Assemblage, although patented on September 4, 1973, after the date of Lank-ton’s alleged discovery, was filed on November 26, 1971. Fasteners, such as nails, are encircled by two (or more if the fasteners’ length so requires) sleeves and held in a parallel, spaced relationship by thin webs connecting the sleeves. The web strips are designed to be one weaker than the other, to provide controlled fracturing. Because of the angular placement of a rib of plastic across the top web connection, the top connection is more prone to fracture when the nail is driven than is the bottom connection, which is traversed by a rib of plastic parallel to the top and bottom edges of the connecting strip. The top rib breaks by compression prior to the breaking of the bottom rib, which breaks by exertion of tension. JUMP 45/1970-30363 is entitled A Pin Assembly for Attaching a Price Tag to a Cloth Product, and was published on November 20, 1970. The publication discloses attaching devices comprising a sharp, piercing bar, a string and an engaging piece, a group of which is held in assembly by adhesive applied to the outer edges of the bar and the engaging piece. The attachment of a tag to a piece of fabric is “executed” by use of an attaching device which JUMP fails to illustrate or describe. The attaching device is loaded with a clip of the pins, the sharp piercing portion of the pin is passed through the hole of a price tag, and “[a]t this moment” the leading attachment is separated from the pin assembly. The adhesive method disclosed in JUMP is claimed to be cheaper to manufacture than pin units connected “at one edge”. In addition to these seven patents and JUMP, defendant cites as prior art the entire plastic molding art, where, according to Samo’s testimony, connections of the sort Lankton devised were commonly known. This aspect of the plastic molding technology, known as “gating”, adds nothing specific to the content of the prior art, but certainly is part of the storehouse of skills and knowledge upon which one skilled in the pertinent arts would reasonably be expected to draw in devising a solution to a problem in the art. Having thus determined the scope and content of the prior art, our task now is to ascertain the differences between that art and the claims at issue. Differences Between the Prior Art and the Claims in Suit It is undisputed that each of the elements of the claimed invention is disclosed in the prior art — plaintiff does not claim that any single feature of the patented structure rises to the level of invention. What is claimed to be unobvious is the way each of these known elements has been combined to produce a useful and unexpected result. The combination may be unobvious even though each of its components is known in the prior art. Maclaren v. B-I-W Group Inc., supra, 535 F.2d at 1377-78. It is also undisputed that none of the prior art references, standing alone, discloses all of the features of Lankton’s invention. Our task, therefore, is to examine the prior art and determine “whether the difference between the prior art and the subject matter in question ‘is a difference sufficient to render the claimed subject matter unobvious to one skilled in the applicable art . ’ ” Dann v. Johnston, supra, 425 U.S. at 228, 96 S.Ct. at 1398. The disclosures of Bone 3,103,666 meet the language of the first nine lines of Claim 1, which describes a clip of attachments in which the penetrating parts are connected by relatively sturdy frangible means which are adapted to be severed in an attaching device. However, the remainder of Claim 1, the dependent article claims and the method claims differ from Bone in that they describe and claim a clip of attachments whose paddle ends are joined by a connection described in the article claims and the method of manipulating the clip whose paddle ends are connected. The predecessors of the Bone patent, Flood 2,825,162 and Flood 2,915,177, disclose bar-string-button attachments mounted in spaced relationship on an adhesive strip to provide for convenient and ready dispensing, adding nothing to Bone. Schumm teaches plastic flexible ties joined in a strip by connections between the enlarged end portions of each tie. However, Schumm’s connections, like those of the Spinner, Paxton, Spinney, Power and Hauck patents cited by defendant, and unlike those of the patent in suit, are not one more readily severable than the other, are not broken at different times, and are not broken by different means and forces in different operations. The connections in Schumm do not differ from one another in any of these respects. The differences between the claims in suit and JUMP are in part similar to those between the claims and Schumm. JUMP, like Schumm, does not disclose connections of different strengths or connections that are to be severed sequentially or by different means. Thus, JUMP fails to meet the disclosures of the claims of the patent in suit relating to comparative severability, sequential severing and th