[1] The opinions of Judge Hand and Judge Mayer 1 set forth in detail the device of the patent and may be referred to. The apparatus of the patent relates to self-playing pianos, in which the keys are put in action by drawing a perforated note sheet transversely over a tracker bar which contains a series of apertures, each communicating by a tube to the pneumatic device for operating the corresponding striker of the note. As the perforations uncover the apertures in sequence the proper actions are successively struck in order to render the musical composition. It is of supreme importance that the note sheet register always with the tracker bar, so that each perforation will come only over the particular aperture for which it is cut. There is a tendency in playing a long piece for the note sheet to shift sideways over the tracker bar; a tendency which must be at once overcome. This is a very delicate operation, involving the attainment of accuracy in order to be commercially successful. Restoration of register may be effected, either by shifting the note sheet back to its old position, or by shifting the tracker bar to a position in proper register with the note sheet. The patent discloses and describes both methods.
The invention of O’Connor was a highly meritorious one and broadly new. The prior art contains nothing which should require it to be narrowly construed. Judge Mayer says:
•‘It undoubtedly represents the first automatic adjusting device which will maintain automatically correct lateral register between the note sheet and *278the tracker bar.” “Complainant and its licensee were the first to produce a successful piano player which would operate properly all the 88 actions of a piano.”
The record abundantly sustains these findings. In the patent, original and reissue alike, what is shown is a device consisting of two bellows rnotors; each motor is operated by air rushing into it through a tube; each tube leads to an aperture in the tracker bar. When such aperture is covered by the note sheet, no air rushes in and nothing happens. When by a sidewise slip of the note sheet one of the apertures is uncovered, air enters and the bellows motor with which the aperture is connected is put in action, moving the tracker bar in one direction; such movement at once re-covering the aperture and putting that bellows motor out of commission. A shifting of the note sheet towards the other side produces similar action by the other bellows motor; one motor moving the tracker bar to the left, and the other moving it to the right. In this way a perfect register is' maintained throughout the entire forward movement of the note sheet, and the note apertures always register with note perforations.
The claims here in controversy are these:
3. The combination with the marginal surface of a traveling sheet, or web, of means for guiding or restoring the web to its normal path when diverted therefrom, a tracker bar, and means contacting with the marginal surface.of the web and held out of operation when the web is in its normal position, for inaugurating the operation of the guiding means.
5. The combination, with a traveling sheet or web, of a tracker bar and means, maintained in inoperative condition by the sheet when in its normal position, for restoring the normal relation of the sheet and the tracker bar when uncovered by the edge of the sheet.
8. In a web-driving apparatus, means for restoring the web and the apparatus into normal relations when deflected therefrom, consisting of rolls for guiding the web, and a tracker bar provided with an aperture adjacent to and wjthin the normal position of the web so as to be covered thereby, and pneumatic devices, the operation of which is inaugurated by the uncovering of the aperture, for restoring the web or the tracker bar to normal position.
10. The combination, with a traveler sheet or web, of a tracker bar, and means, maintained in inoperative condition by the sheet when in. its normal position, for restoring the normal relation of the sheet and the tracker bar when uncovered by the sheet.
21. The combination of a tracker bar having a series of music apertures, means for drawing a perforated note sheet forward over the tracker bar, a pneumatic control opening appurtenant to the trackei bar and arranged so that a lateral deviation of the note sheet will change its condition, a pneumatic motor connected to adjust the lateral relation between the note sheet and tracker bar, and connections between said control opening and said, pneumatic motor arranged so that, when a lateral deviation of the note sheet changes the condition of the control opening, the pneumatic motor will operate to-restore the normal lateral relation between the tracker bar and note sheet before the forward run of the note sheet in abnormal lateral position can produce discord.
22. The combination of the tracker bar having a series of music apertures,, means for drawing a perforated note sheet forward over the tracker bar, a pneumatic guide opening appurtenant to the tracker bar and arranged so that a lateral deviation of the note sheet will uncover the same, a' pneumatic motor connected to adjust the lateral relation between the note sheet and tracker bar, and connections between said guide opening the said pneumatic motor, arranged so that, when a lateral deviation of the note sheet uncovers the guide-opening, the pneumatic motor will operate to restore the normal lateral rela-*279fton between 1be tracker bar and note sheet before the forward run of the note sheet in abnormal lateral position can produce discord.
Claims 3, S, 8, and 19 are identical with claims similarly numbered in the original patent.
Tile defendant uses one bellows motor, instead of two, as shown in O’Comior’s description and drawings. This bellows motor is operated iu one direction or the other by pneumatic action — in one direction by pneumatic pressure directly; in the other by the expansion of a spring, which has been contracted by pneumatic pressure. Defendant has one aperture only, because it has only one bellows to move, and contends that it has avoided infringement by dispensing with the second bellows and aperture.
We arc satisfied that infringement is not avoided by this simple change, since the patent is a pioneer one, entitled to a liberal construction and a broad range of equivalents. If part of a combination is stated to be a square table on four legs, and neither the shape of the table nor the number of legs is a matter of any importance, so long as the table is large enough and is maintained in a horizontal position, a triangular table on three legs would be an equivalent of the element specified. The defendant’s double bellows is in fact two bellows placed together and working by a combination of air pressure and spring alternately in opposite directions. The exact location of each of these bellows is not of the essence of the invention, so long as each performs its function of producing a correct register between the perforations in the note sheet and the note apertures in the tracker bar. None of the claims here relied on is limited to two bellows and two apertures, nor does anything in the prior art require that they should be so limited in order to save them. If other prior inventors had employed a double acting bellows operated .through a single opening, of course O’Connor would he held strictly to liis two bellows construction; but as he was a pioneer so far as this improvement is concerned — the first to restore register by moving tracker bar or note sheet by the action of bellows motors, set in motion by uncovering auxiliary apertures in the tracker bar — infringers cannot escape these claims by locating their bellows or one member of their bellows in a different place.
Defendant, further seeks to avoid infringement because in its device the aperture in the tracker bar is never fully covered by the note sheet, some air is always passing in. But when the note sheet is in a normal position the small amount of air thus passing in is so neutralized by springs, etc., about the motors that its effect is nil. Whenever the aperture is by a displacement of the note sheet more widely uncovered, air which enters sets the bellows in motion to produce action in one direction. Whenever by a different displacement of the web the aperture is more fully covered, less air enters and there is a contrary action of the bellows. Defendant’s device may evidence improvement, possibly' even patentable improvement, in simplification of structure or saving of cost; but that will, not negative infringement, when in substantially the same way substantially the same results are produced, and the prior art justifies a broad construction of the claims. Defendant’s device is a plain equivalent of what is shown and claimed in the patent; its *280double action bellows has substantially the same parts, acting in substantially the same way to accomplish the same results, viz., to move the tracker bar one way or the other, so as to maintain a proper register at all times between note sheet and tracker bar.
If the original patent had never been changed, or if this second reissue were the original patent, the state of the art being shown in the record before us, we are satisfied that defendant’s device complained' of (Exhibit 4) is an infringement of the claims above quoted. Does its reissue history call for any different conclusion?
In the suit against the Amphion Company, supra, the defendant’s device was held not to infringe. The O’Connor patent, as we have seen, automatically sets the motors in operation by uncovering an aperture in the tracker bar. The note sheet, which runs smoothly, slides off or on the aperture; the surface of the sheet is either superimposed over the aperture or is withdrawn therefrom. This is spoken of as “surface control.” In the Amphion device the automatic action was the engagement of the edge of the note sheet (whenever it slipped out of register) with the end of a lever. This is spoken of as “edge control.” It was held in the Amphion Case that the language of the specifications and claims precluded a construction which would cover a device operating automatically under “edge control.”
The owner of the patent — O’Connor had sold and assigned it to complainant — was dissatisfied with this result and consulted a lawyer who had not theretofore had anything to do with the case. He recommended applying, for a reissue, modifying the language of the patent so as to cover “edge control,” and prepared the papers and made the application. Apparently he formed the impression that the prior art was such that the claims of the original patent were too broad. In the proposed reissue patent he struck them all out, and substituted- four claims, each of which was restricted to “two bellows motors” and “two guide openings.” The proposed reissue also contained seven specific disclaimers, none of which affected the number of bellows motors or apertures. This reissue, as asked for, was granted August 15, 1911; it was applied for April 1, 1911, less than a month after final decision in the Amphion Case.
After this reissue was received by the owner of the patent, it realized that a very serious change had been made from the original patent. It took the matter up with counsel, other than the one who had obtained the'first reissue and in December of the same year applied for a second reissue, pointing out that the error of the first reissue was:
“That the specification thereof is not sufficient, and that said insufficiency consists particularly in the omission to include in said reissue patent the claims appearing in applicant’s original letters patent No. 789,053, dated May 2, 1905, and in the omission to claim a combination substantially the same as the claims of said first reissue, but covering only a single guide opening, as particularized in a large number of the claims of said original patent.”
No change was sought to be made in the descriptive part of the specification of the first reissue, which set forth two bellows motors and two apertures, as indeed the original description did. The proposed second reissue contained the original claims, which had been *281dropped in tlie first reissue. These include 3, 5, 8, and 19, supra. Some additional claims were added, among which are 21 and 22, supra. The application was made in the usual form, accompanied by oath that:
"The errors which render said prior reissue patent so inoperative arose from inadvertence, accident, or mistake, and without any fraudulent or deceptive intention on the part of deponent.”
[2] The second reissue was granted as prayed April 2, 1912. The statute (Rev. St. § 4916 [Comp. St. 1913, § 9461]), authorizing reissue when error has arisen “through inadvertence, accident, or mistake, and without fraud or deceptive intention,” is undoubtedly intended for relief of meritorious inventors who are likely to lose their invention through some accident or mistake. When no intervening rights appear, it should be and has repeatedly been liberally construed. It may be noted that we have not here the situation presented in some of the authorities, where the reissue contains a claim which, after controversy with the Patent Office pending his earlier application, the inventor abandoned, acquiescing in its rej ection.
[3] Every one of these claims 3, 5, 8, and 19 was allowed by the Patent Office, and the only “abandonment” of them relied upon is their omission from the first reissue. Defendant’s position seems to be that there never can be a reissue of a claim once allowed in the original and omitted from a first reissue; but to this proposition we do not assent. Giant Powder Co. v. Safety Nitro Powder Co. (C. C.) 19 Fed. 510; Celluloid Manufacturing Co. v. Zylonite Brush & Comb Co. (C. C.) 27 Fed. 293; Sawyer Spindle Co. v. Eureka Co. (C. C.) 33 Fed. 836. It may be noted, also, that the claims here are not broader than the original claims, as they were in many of the cases cited on the argument. Inasmuch as the statute provides for “inadvertence, accident, or mistake,” not, as defendant paraphrases it, “mistake inadvertently committed,” there is no reason why the mistake should not be corrected even though it occurred in an attempt to amend.
The first reissue was certainly not obtained by “inadvertence.” It was the result of the deliberate attempt of a patent solicitor to modify an existing patent; but it was, so far as we can see, none the less a mistake, and not merely a mistake of judgment, as when applicant’s solicitor submits to rejections by the Patent Office. The mistake was as to what the prior art contained. It was believed to be much more extensive than the patentee supposed it to be when he applied for his original patent, so broad that his claims could not be sustained unless they were strictly confined-to two bellows motors and two apertures. But, now that the prior art is displayed, it is apparent that it is not so broad as the owner of the patent and his solicitor supposed it was when application was made for the first reissue. When this misconception as to condition of the prior art was discovered, application was promptly made for a second reissue, and the affidavit on which such application was based truthfully stated— at least, there is nothing shown to negative its truthfulness — that the omission from the first reissue of the original claims was a “mistake.” That there was “any fraudulent or deceptive intention” we find no evidence at all.
*282Before the second reissue was granted, however, and while the public was advised that the rights which complainant claimed were those only announced to the public in the first reissue, defendant began the manufacture of player piano actions with automatic regulation of the register between note sheet and tracker bar. It used the fundamental idea of O’Connor, viz., moving the tracker bar to one side or the other, so- as to keep its apertures in register with the note sheet perforations, effecting this motion by the operation of a bellows motor, setting the motor in operation by the admission of air to it through an auxiliary aperture in the tracker bar, and automatically regulating the initiation of such motion by means of the note sheet moving over the auxiliary aperture. The defendant’s device, however, consisted of a single bellows motor, moved one way or the other as it was exposed to pressure or suction. This device (Exhibit N), was not covered by the first .reissue, the claims of which were confined, to two motors and apertures. That defendant entered.upon the manufacture and sale of these automatic trackers before the grant of the second reissue madé public the fact that complainant was making claim to the broad invention covered by the claims here in issue is' fully established. That only five of these player piano actions were actually sold is immaterial. Not only the five are free from this reissue, but- the business of manufacturing and selling automatic trackers of the type shown in Exhibit N, which was entered into in the belief, warranted by complainant’s conduct and mistakes, that defendant’s, tracker would not be challenged as an infringement under either the original patent, which had been given up, or the reissue, which did not cover it, cannot be interfered with under this second reissue.
The defendant is now making and selling a modification of this Exhibit N,. which is known as Exhibit 4. In its original double acting bellows motor the air which came through the auxiliary aperture impinges upon a diaphragm which raised or lowered a stem carrying two valves, the movements of which brought to the bellows motor alternatively “pressure air” or “suction air.” In the present type the diaphragm, stem, and v.alves are discarded, and the air from the aperture is brought directly to the inside of the bellows motor; connection between the bellows motor and the air chest being regulated by a small disk having a so-called'bleed opening therethrough. The improvement simplifies structure, presumably costs less, and is said to be more efficient, operating more quickly. We do not see, however, that it has so changed the type shown in Exhibit N as to make it no longer free from the claims of the second reissue.
We therefore reach the conclusion that complainant is estopped from claiming infringement by this particular defendant in continuing the manufacture and sale which it entered upon while the first reissue was the only public announcement of complainant’s alleged monopoly.
The decree is affirmed, with costs.
See note at end of case.