§1035. Evidence under the Twelfth Defence: Ambiguity of the Description. The twelfth defence avers the ambiguity of the description. It raises the issue whether the disclosure of the invention is sufficient to enable persons skilled in the art to practise it without the exercise of their own inventive faculties. The patent makes a prima facie case for the plaintiff on this issue, and the defendant must contradict it by satisfactory evidence.1 The testimony most pertinent and convincing is that of practical mechanics, who have endeavored to construct and use the invention by following the directions given in the patent.2 The evidence of scientific experts on this point is also proper. A single instance of success or failure in the endeavor of a practical mechanic to employ the invention is, however, of more weight and value than numerous opinions to the contrary. No question as to the intention of the inventor arises under this defence, and evidence indicating the existence of a fraudulent purpose is, therefore, inadmissible." § 1036. Evidence Claims. under the Thirteenth Defence: Excessive The thirteenth defence asserts that the Claim of the patent is excessive and has not been cured within a reasonable time by a disclaimer. Whether the Claim is excessive is a mixed see Wood v. Underhill (1847), 5 How. ; 2 Robb, 588. sary to show fraudulent intent is for the jury to decide, see Gray v. James (1817), Peters, C. C. 394; 1 Robb, 120. That the claim of ambiguity in the See also as to this subject §§ 494, description is rebutted by the testimony 969, and notes, ante. § 1035. That the patent is prima facie evidence that the specification is sufficient, see Poppenhusen v. New York Gutta Percha Comb Co. (1858), 2 Fisher, 62. That the burden of proof as to the uncertainty of the patent rests on the defendant, see Westlake v. Cartter (1873), 4 O. G. 636; 6 Fisher, 519. 2 That the jury are to say on the evidence of persons skilled in the art whether the description is clear enough to enable them to make the invention, of competent mechanics that they could construct the device from it, see Wayne v. Holmes (1856), 2 Fisher, 20; 1 Bond, 27. 8 That the defendant need not prove that the plaintiff intended to deceive by his erroneous specification, see Grant v. Raymond (1832), 6 Peters, 218; 1 Robb, 604. As to the sufficiency of the description, see §§ 490-493, and notes, ante. As to this defence in general, see § 970 and notes, ante. question of law and fact. The court is to construe the Claim as matter of law and instruct the jury as to the nature of the invention which it purports to embrace. The jury are to decide from the evidence whether the Claim as thus interpreted includes more than the actual invention.2 Upon this point of the defence the patent is prima facie evidence of the correctness of the Claim. The defendant must, therefore, prove the essential characteristics of the true invention and show that it does not comprise all the substantial features covered by the Claim. The evidence on both sides consists of specimens, drawings, or descriptions of the actual invention, illustrated and explained by expert witnesses. Upon the question whether an excessive Claim has been cured by a disclaimer within reasonable time, the patent furnishes no evidence. The burden of proof properly falls upon the plaintiff, and he should be prepared to show either that he has filed the disclaimer without unreasonable delay, or that a reasonable time for filing it has not elapsed since he became aware of the existence of his error. An inventor is not chargeable with notice that his Claim is excessive until it has received judicial interpretation in the court of last resort, except in cases where the excess is evident upon its face. The reasonableness or unreasonableness of the delay is matter of law for the court upon the facts disclosed by the evidence. If the amendment is made immediately upon the discovery of its necessity, there is no delay. When the delay is unavoidable it cannot be unreasonable. Although avoidable, it will not be unreasonable unless protracted to an extreme degree, where no other interests are at stake and the public are not liable to be misled. § 1036. 1 That the Claims of a patent are construed by the court as matter of law, see §§ 732, 733, and notes, ante. 2 That the jury are to decide whether the Claims set forth the actual invention, see Teese v. Phelps (1855), 1 McAllister, 48; Orr v. Burwell (1849), 15 Ala. 378. 8 That no duty to disclaim arises until the plaintiff becomes chargeable with knowledge of the excess, see Kittle v. Hall (1887), 30 Fed. Rep. 239; and cases cited in notes to § 646, ante. 4 That the court must decide as to reasonable delay, see § 646 and notes, and § 690, notes 5 and 8, ante. 5 That an unavoidable delay is not unreasonable, see Hartshorn v. Eagle Shade Roller Co. (1883), 18 Fed. Rep. 90; 25 O. G. 1191. 6 That the effect of a delay upon other parties may show whether or not it is unreasonable, see Stutz v. Arm If the plaintiff maintains that a disclaimer has been filed, it may be proved by a certified copy from the Patent Office. The evidence in reference to delay must show when the inventor first discovered that his Claim embraced more than the actual invention, and the circumstances which compelled him to postpone the amendment of his patent. Upon this portion of the issue the defendant may produce any testimony tending to fix an earlier date for the discovery of the error, or to prove that the delay of the inventor was unjustifiable in view of his own condition or that of others interested in the invention. When this defence applies to more than one Claim in the patent, evidence appropriate to each must be introduced.7 § 1037. Evidence under the Fourteenth Defence: Ambiguity of the Claim. The fourteenth defence asserts the ambiguity of the Claim. This defence raises a question of law for the court, and except in certain rare cases presents no issue for the jury. A Claim is ambiguous when the court is unable to ascertain from it what the patentee intended to protect as his invention.1 The allowance of the patent by the Patent Office is a decision that its Claims are not ambiguous, and this decision is prima facie correct. The courts, however, in the discharge of their duty in construing the patent must encounter this question and settle it, though every presumption is in favor of the plaintiff, and the patent will, if possible, be sustained. For this purpose not only the Claim itself, with the Description and drawings, will be considered, but extraneous evidence may be offered to show the meaning of technical terms, or any other facts generally known in the art by which its obscure phrase strong (1884), 28 O. G. 367; 20 Fed. Rep. 843; and cases cited in note 7, § 690, ante. ▾ That each Claim of the patent may be contested on the ground of excess, see 537, note 4, ante. See on the matter of excessive Claims §§ 537, 643, 971, and notes, ante. On the matter of disclaimer, see §§ 640-652, and notes, ante. § 1037. For ambiguity of Claim, see §§ 512-515, 537, 972, and notes, ante. That whether the Claims are ambiguous is a question of law for the court, see Wayne v. Holmes (1856), 2 Fisher, 20; 1 Bond, 27. ology may be rendered intelligible. The introduction of such evidence by the parties is not a matter of right, but of judicial discretion. It consists principally of the testimony of experts, and of persons practically acquainted with the art, or of copies of papers in the Patent Office relating to the invention. When the Claim itself refers to facts, the existence and character of which must be determined before the Claim can be construed, evidence concerning these facts may be submitted to the jury, whose finding thereon thus enters into and becomes an element in the interpretation of the Claim.5 § 1038. Evidence under the Fifteenth Defence: Surrender of the Letters-Patent. The fifteenth defence alleges that the patent described in the declaration has been surrendered to the government. The production of the patent by the plaintiff is prima facie evidence that it is still in force, and the defendant must therefore prove the contrary. His evidence consists of certified copies from the records of the Patent Office showing the fact of surrender, the ownership of the patent by the parties who surrendered it, and its cancellation or the re-issue of an amended patent in its stead.1 §1039. Evidence under the Sixteenth Defence: Repeal of the Letters-Patent. The sixteenth defence avers that the patent described in the declaration has either been repealed in toto by a judgment 2 That the court in construing a Claim may resort to extraneous evidence, see §§ 739-741, and notes, ante. 8 That evidence is not admissible, as a matter of right, to aid the court in construing the Claim, see § 732, and notes, ante. 4 That the court may avail itself of expert testimony, see Day v. Stellman (1859), 1 Fisher, 487. That a drawing may be used in evidence to interpret an ambiguous specifi cation, but cannot supply the entire want of any part of a specification or Claim,.see Tinker v. Wilbers Eureka Mower & Reaper Mfg. Co. (1880), 1 That the jury apply the construction given by the court to the facts, and if the construction given is condi. tioned on the existence of extraneous facts, the jury are to find such facts and then apply the Claim as interpreted by the court, see Silsby v. Foote (1852), 14 How. 218; Emerson v. Hogg (1845), 2 Blatch. 1. § 1038. 1 For a statement of the requisites and mode of a surrender, see §§ 696-699, and notes, ante. See as to this defence § 973 and notes, ante. in favor of the United States against the owner of the patent, or has been annulled in whole or in part in a proceeding instituted or defended by some person interested in an interfering patent. On both these issues the patent is prima facie evidence for the plaintiff. The defendant may show its repeal by a properly authenticated copy of the judgment, or where the patent, in pursuance of this judgment, has been returned to the Patent Office and been cancelled he may produce a certified copy of the record of such cancellation. In proving that the patent has been annulled, the fact and scope of the judgment of avoidance may be evidenced by a copy from the records of the court, while copies of the record title in the Patent Office disclose that the plaintiff or his assignor was the party against whose interest in the patent such judgment was rendered.2 § 1040. Evidence under the Seventeenth Defence: Want of Title in the Plaintiff. The seventeenth defence denies the legal title of the plaintiff to the patent. When the plaintiff is the patentee, the patent is prima facie evidence upon this point in his favor, and the defendant must sustain his denial by satisfactory proof. But where the plaintiff is an assignee or grantee, the burden rests upon him to establish the conveyances by which he claims to have derived his title from the patentee. The original assignment or grant is admissible for this purpose, though not recorded before the action was commenced, and is sufficient if in writing and executed in conformity with the local law. In the absence of the original instruments, certi § 1039. 1 As to the repeal of patents see §§ 725-730, and notes, ante. 2 As to the annulling of patents, see §§ 721-724, and notes, ante. See as to this defence § 974 and notes, ante. § 1040. 1 That the patent is prima facie evidence that the patentee owns the patented invention unless the contrary is proved, see Fischer v. Neil (1881), 6 Fed. Rep. 89; 19 O. G. 603. As to this defence see §§ 937, 975, and notes, ante. 2 That an assignment may be of fered in evidence, whether recorded before or after suit, see Pitts v. Whitman (1843), 2 Story, 609; 2 Robb, 189. That the assignment of a patent duly acknowledged before a notary may be put in evidence in New York, and the signatures of the assignors need not be proved, such assignment being valid by the laws of that State, see New York Pharmical Association v. Tilden (1883), 21 Blatch. 190; 23 O. G. 272; 14 Fed. Rep. 740. |