22. Any person may appear and show cause against the extension of the patent. But if, after all is done, the commissioner is fully satisfied that, having due regard to the public interest, it is just and proper that the term of the patent should be extended, by reason of the patentee, without neglect or fault on his part, having failed to obtain from the use and sale of his invention a reason able remuneration for the time, ingenuity, and expense bestowed upon the same and tlate introduction thereof into use, it is rendered his duty to grant the extension as prayed for. And thereupon the patent has the same effect in law as though it had been originally granted for the term of• twenty-one years. The • extension enures only to the benefit of ,the patentee, and not of his assignees, unless 'he has contracted to conley to them an inte - rest or right therein. But the assignee has right to continue the use by himself of the ,patented machine. which he is using at the time of the renewal, 4 Hovv. 646, 709, 712 ; 19 id. 211 • 3 McLean, C.•C. 250 ; 4 id. 526 ; Blatchf 'C. C. 167, 258 ; 2 id. 471; 3 Stor.
C. C. 122, 1,71 ; and a purchaser may repair his own machine, when necessary, though the repair consist in the replacement of an essentiai part of the combination patented. 9 How. 109. Upon the granting of an ex tension, al. additional fee of fifty dollars is .required A.et c.f 1861, f 10.
The act ot the commissioner in granting the extension is conclusive, in the absence of fraud or excess of jurisdiction. , 2 Curt. C. C. 506.
23. Of the assignment of patents. The, eleventh section of the act of 1836 authorizes, the assignment of• a patent, either .in whole, .or in' part, by any instrument in writing,— which assignment must be recorded in the ,patent cifice within three months from the execution thereof. But it has been held that this provision for recording i's directory merely, for the• protection of' bond fide pur-, !chasers without, notice, and not an absolute prerequisite to the validity of the asaignment .2 Stu. CI C. 526 2 Blatchf. C. C. 144; 3 McLean, C. O. 427 ; 4 td. 527 ; 6 Ind. 428 ; .28 Mo. 539 ;, 2 N 11. 61 ; 18 Conn. 377. It .has been. accordingly,' determined that the• !recording, might . take place uot only after• 'the expiration of , three ritonths, but even ;after suit. brought. 2 Stor. e. C. 609.
24. Strictly,speaking, the. wIrd " assign ment" applies to the transfer of the enure, (interest of the inventor, or to a fraction that, entire interest running -throughout the' .whole United: States. , A conveyance ot an exclusive interest within -and throughout any ,specified part or portion of 'the United Sta,tes.
:is more properlY lerhiminated a grant • A. mere authoritylor. permission to nse, sell, or manufacture the thing patented.. either in the whole United 'States in any specific .portion. thereof, is known as a license_ But all three. are sometimes included under the, gtneral term of an assignment. Where the, 'assignment, however, is not. ot the patent Itself, or. of any undivided part thereol, or 'of any right therein limited• Ms, particular 'locality, but oonstitutes mcrely a license or .authority from the patentee, not •exclusive and riot transferring any interest in the 'patent itself, •it has, been held that it need mot be recorded. 2 Stor. 0, C. 5-41. Acts in pais will sometimes justify the presump tion of a license. 1, How. 202 ; 17 Pet. 228; 3 -Stor. C. .0. 402. As to the distinction 'between a license and assignment, see 10 ,How. 477.
An assignment may be Made prior to the granting of a patent. And when duly made and recorded,. the patent may be issued to the assignees. See Act of 1836, !0 6. This. however, only applies to cases of assign ments proper, as contradistinguished from grants or licenses. The application must, however, in such cases he made and the specification sworn to by the. inventor. See 5 McLean, C. C. 131 ; 4 Wash. C. C. 71 ; 4 Mas. C. C. 15 ; 1 Blatchf. C. C. 506. The assignment transfers the right to the as signee although the patent should be after wards issued to the assignor. 10 How. 477. See 1 Wash. C. C. 168 ; 4 Mas. C. C. 15 ; 7 Ham. 249.
It has also been held by the attorney-gene ral of the United States that, if the inventor desires the patent to issue to himself and another person jointly, it is not enough for him to convey an interest to the other party, retaining the remainder himself ; but he must make a joint conveyance to himself and the other party.
The fee for recording an assignment, if it does not contain more than three hundred words, is one dollar ; if more than three hundred and not more than one thousand, it is two dollars ; and if more than one thousand, it is three dollars.
25. Of joint inventors. The patent must in all cases issue to the inventor, if alive and if he has not assigned his interest. And if the invention is made jointly hy two in ventors, the patent must issue to them both. This is equally the case where one makes a portion of the invention at one time and another at another time. A failure to ob serve this rule may prove fatal to the validity of the patent. See 1 Mas. C. C. 447.