within the second class. His was not a pioneer invention. His improvement was too narrow and limited to entitle it to protection by such a breadth of signification of the term "mechanical equivalent" as would make the rectangular frame built up out of four separate bars and the complicated clutch mechanism of the Little Wonder the mechanical equivalent of Henderson's U-shaped bar, the drum and the means of operating it rotatably supported on the side members of his bar. The application of a meaning of this term much more restricted would render the patent to Henderson void, for his hoisting machine with the U-shaped bar and the drum rotatably supported on its side bars as described in Murray's patent is much nearer to the mechanical equivalent of Murray's device than the Little Wonder with its rectangular frame built out of four separate bars and its complicated clutch mechanism is to the mechanical equivalent of Henderson's hoisting machine.

[4] 3. Again, the statute requires the inventor to "particularly point out and distinctly claim the part, improvement, or combination which he claims as his invention or discovery." Revised Stat. § 4888; 8 U. S. Comp. Stat. 1916, § 9432, p. 10214. When under this statute the inventor has done this, he has thereby disclaimed and dedicated to the public all other improvements and combinations apparent from his specification and claims that are not evasions of the combination or device he claims as his own, and has estopped himself as against those who subsequently use them from claiming or securing any monopoly

thereof.

*

*

*

"The purpose of a claim in a patent is to notify the public of the extent of the monopoly secured to the inventor, and, while it is notice of his exclusive privileges, it is no less a notice, and a legal notice, upon which every one has a right to rely, that he disclaims, and dedicates to the public, any combination or improvement, not a mere evasion of his own, which he has not there pointed out and distinctly claimed as his discovery or invention. Every one has the right to use every machine, combination, device, and improvement not claimed by the patentee, without molestation from him." Adams Electric R. Co. v. Lindell R. Co., 77 Fed. 432, 451, 23 С. С. А. 223, 242; Keystone Bridge Co. v. Phoenix Iron Co., 95 U. S. 274, 278, 24 L. Ed. 344; Miller v. Brass Co., 104 U. S. 350, 352, 26 L. Ed. 783; McClain v. Ortmayer, 141 U. S. 419, 424, 12 Sup. Ct. 76, 35 L. Ed. 800; Dobson v. Cubley, 149 U. S. 117, 121, 13 Sup. Ct. 796, 37 L. Ed. 671; Stirrat v. Mfg. Co., 61 Fed. 980, 984, 10 C. C. A. 216, 220; McBride v. Kingman, 97 Fed. 217, 223, 38 С. С. А. 123, 129; Expanded Metal Co. v. Board of Education, 111 Fed. 395, 397, 398, 49 С. С. А. 406, 408; Ο. H. Jewell Filter Co. v. Jackson, 140 Fed. 340, 347, 72 С. С. А. 304, 311.

In each of Claims 1 and 3 of his patent, Henderson specifically claimed a combination with other mechanical elements of the crossbeams or putlogs of a scaffold and one or more hoisting devices, and expressly specified that each hoisting device he claimed consisted of a U-shaped metal bar and a hoisting drum rotatably supported by the side members of that bar. He might have described and claimed a hoisting device consisting of the U-shaped bar and the drum rotatably supported on the side members thereof and a rectangular frame built up out of four metal rods and the complicated clutch mechanism made by Whitney. He did not do so. He confined his claim to a hoisting device consisting of his U-shaped frame bearing a drum rotatably supported on the side members thereof and thereby disclaimed, dedicated to the public, and estopped himself from successfully asserting a claim of a monopoly of the manufacture, sale, or use in his combinations of a hoisting machine which has neither U-shaped bar nor drum supported by the side members thereof, but consists of the rectangular frame and clutch mechanism of the Little Wonder.

For the reasons which have now been sufficiently stated, the evidence in this case does not, in the opinion of the court, sustain the conclusion that the manufacture and sale of the Little Wonder, whether used edgewise or broadside to the wall of the building, constitutes contributory infringement of either of the combinations described in Claims 1 and 3 of the patent to Henderson. The interlocutory decree granting the injunction against the manufacture and sale of that machine by Mr. Whitney must therefore be reversed, and it is so ordered.

(243 Fed. 188)

GENERAL ELECTRIC CO. v. ELECTRIC CONTROLLER & MFG. CO. * (Circuit Court of Appeals, Sixth Circuit. May 18, 1917.) No. 2884.

1. PATENTS 328-VALIDITY AND INFRINGEMENT CONTROLLER FOR ELECTRIC MOTORS.

The Carichoff patent, No. 763,658, for a controller for electric motors, claim 7, was not anticipated, and discloses invention, covering a meritorious improvement; also held infringed.

2. PATENTS230-INFRINGEMENT

"EQUIVALENCY."

"Equivalency" in the patent law is not necessarily mutual, and whether the device of a defendant is the equivalent of that of complainant's patent depends upon the scope of the claim in suit.

[Ed. Note.-For other cases, see Patents, Cent. Dig. § 367.

For other definitions, see Words and Phrases, First and Second Series, Equivalent.]

3. PATENTS 112(4)-INFRINGEMENT-PRESUMPTION FROM ISSUE OF LATER PATENT.

The issue of a later patent raises no presumption of noninfringement of an earlier, and usually does not even tend to establish that conclusion. [Ed. Note. For other cases, see Patents, Cent. Dig. § 165.]

Appeal from the District Court of the United States for the Eastern Division of the Northern District of Ohio; John H. Clarke, Judge. Suit in equity by the General Electric Company against the Electric Controller & Manufacturing Company. Decree for defendant, and complainant appeals. Reversed.

W. K. Richardson, of Boston, Mass., for appellant.
Karl Fenning, of Cleveland, Ohio, for appellee.

Before KNAPPEN and DENISON, Circuit Judges, and HOLLISTER, District Judge.

DENISON, Circuit Judge. The appellant filed in the court below the usual infringement suit, based upon claims 5, 6, 7, 28, 29, 30, 31,

For other cases see same topic & KEY-NUMBER in all Key-Numbered Digests & Indexes • For opinion on application to modify mandate, see 243 Fed. 1007, 156 C. С. А. 664.

32, 45, and 47 of patent No. 763,658, issued June 28, 1904, to the Sprague Electric Company as assignee of the inventor, Carrichoff. Upon the argument below, it relied chiefly, if not wholly, upon 5, 6, and 7. The bill was dismissed by a decree adjudging all the 10 claims void for want of invention. Upon this appeal, complainant assigns error in the conclusion as to each of these claims; but, by its brief in this court, it rests its appeal solely upon claims 6 and 7. It does this, coupled with an express disclaimer of acquiescence in the decree as to the remaining claims affected, but for the purpose, as it says, of simplifying the issue.

[1] The patent relates to a controller for an electric motor. Claims 5, 6, and 7 are given in the margin.1

We do not attempt any complete statement of construction or operation. The general aspect of these matters is familiar to counsel and to the parties, and to all who might be interested in patents involving the same subject-matter; to others they are not important. We do not undertake to achieve perfect accuracy either in the use of the technical terminology or with reference to operative conditions; we propose only so much of statement as to make our conclusions intelligible. The rotation of the armature of an electric motor, resulting from the current conducted thereto over the line from the source of power, creates a counter electromotive force which (so to speak) neutralizes or dams back a large part of the original electromotive force. The net resultant becomes the effective operating power, and the motor is so built as to be adapted and fitted for only this net resultant. For example, it may be supposed that the line will furnish 100 power units, and that the counter electromotive force, at the preferred motor speed, will be 80 units. The motor will then be so constructed that it will best operate under a net load of 20 units, but will be able to carry 40 without injury, while it will be destroyed by the total load of 100, and, indeed, will be liable to injury by much more than 40. Accordingly, the current is taken from the line to the motor through a series of resistances, which, in this supposed case, allow only 40 to pass. As the motor speeds up, and the counter electromotive force develops, the net current will be reduced to 8 units, and the device will be inefficient. To avoid this result, as soon as the net current falls to 20, a section of resistance should be cut out, and the amount of current admitted from the line increased to 60, and, in the same way, the amount should be successively stepped up to 80 and 100. The device by which the resistance is thus cut out step by step, and the current controlled, is called a rheostat, and it consists of a switch maintaining at one pole a constant contact with the line and at the other end selective contact with the resistances. In its simplest form, this is manually operated, as in the familiar instances of the controller of the electric street car or automobile. For many uses manual control is not practicable, and automatic electric control becomes necessary.

Before Carrichoff's improvement, this automatic control had been accomplished with more or less success by three classes or types of apparatus. In the first or time limit class, some timing device was arranged to operate the successive resistance cut-outs at predetermined and fixed time intervals. This is so far from Carrichoff's system that it, together with the manual control type, needs no further consideration.

In the second type, the current generated by the motor and representing the counter electromotive force, is led through a series of switches, the solenoid magnets of which are so wound that the first will be operated when this current reaches 40 units, and will then cut out a section of resistance; the second, when it reaches 60, and will then cut out another section, etc. It seems to be clearly established that this system, under many and perhaps under usual conditions, is efficient, but that under other conditions which are not uncommon, and which, with certain installations, are to be expected, is not satisfactory. It has direct bearing upon Carrichoff's improvement only in one respect hereafter to be mentioned.

The third type touched Carrichoff more closely. Indeed, this system was exemplified in the patent to Sprague, issued when he and Carrichoff were both in the employ of the Sprague Company, and Carrichoff, in his specifications, expressly declares his invention to be an improvement upon the plan of this Sprague patent. The Sprague plan, as far as it pertained to this particular subject, involved two features, which may be called his primary and his secondary features, and the claims of his patent (whether valid or not) seem to be partly generic, as resting solely on this primary feature, and partly specific, as resting upon this secondary feature, when employed as a means of carrying out his generic thought. The primary feature consisted in the use of an automatic throttle to control the action of the successive resistance cut-outs. This throttle consisted of a solenoid magnet switch, interposed in the main circuit. So long as the current exceeded (e. g.) 20, the magnet remained energized and its switch contacts were held up and open. When the current dropped below this point, the contacts dropped, an independent circuit from the master switch and leading through these throttle contacts was closed, and current was carried to and operated a resistance controller device, whereby some resistance was cut out, the line current admitted to the motor increased above 20, and the throttle switch contacts were again opened. This operation would be automatically repeated as often as the current fell below the predetermined point and until the resistances were all cut out.

For his secondary feature or specific form of controller mechanism, Sprague provided a revolving drum carrying contacts so arranged that, as it revolved, it would successively cut out the resistance sections. This part of the operation-the actual throwing of the switches which controlled the resistance sections-was as completely mechanical as if the drum had been revolved by hand; but he gave electrically automatic revolution to the drum by operating it with a small independent motor, called a pilot motor, and this motor was actuated by current through the throttle contacts, when they closed as above described. With each such closing of the throttle, the pilot motor would be operated until the drum had revolved enough to cut out one resistance, and so increased the line current in the motor and at the throttle, and so opened the throttle and stopped the pilot motor. As with reference to the system last described, this pilot motor drum system gave fairly good satisfaction, and was and is considerably used, but has certain comparative disadvantages.

We come, now, to the Carrichoff improvement. He adopted and employed what we have called the generic or primary part of Sprague's invention, viz., the solenoid magnet throttle, as the means of automatically sending out an electric messenger whenever the motor current fell to the point which called for an increased current from the line, which messenger should operate one step in the resistance-shunting process. For Sprague's pilot motor drum, Carrichoff substituted a series of solenoid magnet resistance shunting switches (which, for convenience, we will hereafter refer to merely as magnets 1, 2, 3, etc.). The current which is caused by the closing of the throttle contact, energizes magnet 1, whereby its contacts are raised and closed, one section of resistance is cut out, and the line current is shunted through this closed switch around that resistance section. The lifting of the core of magnet 1 at the same time lifts a plate, closing contacts in a circuit from the master switch through the magnet winding to the ground, whereby this magnet continues to be energized and so to cut out this section of resistance, regardless of the subsequent opening or closing of the throttle. The same lifting action also closes contacts between magnets 1 and 2, whereby there is completed a circuit from the master switch through magnets 2 and 1 to the throttle and ground, so that the closing of the throttle contacts thereafter will close this circuit and energize magnet 2. The same thing then happens as with magnet 1; another section of resistance is cut out, and a maintaining circuit for 2 is closed. The same steps occur in succession with the other magnets. The result is that, when the current in the motor circuit falls below 20 (continuing to use our arbitrary illustration), the throttle closes, the first magnet is energized, its section of resistance is cut out, it is released from control by the throttle, the next magnet is rendered subject to that control ready for the next step in the process, and so on.