"It is now established in this circuit that when such a situation exists-at least when there is more than a single vessel at the pier head-and fog signals indicate the approach of another vessel, there should be sounded some warning of the presence of the obstructing vessels; not navigating or anchored signals, but some other sound, to take the place of sight, whether it be given by beating a pan, or blowing a mouth horn, or using a watchman's rattle or a megaphone. When the tug which had the tow in charge has been at hand, she has been held in fault for not giving such warning. When she is absent, reasonable care and prudence should be exercised by the master of a boat thus left tied up, when conditions indicate that danger threatens."

See, also, The Express, 212 Fed. 672, 129 C. C. A. 208 (1914).

In the instant case the Bern, which had the tow in charge and was bound to sound some warning of the presence of the obstructing tow, did nothing. Under these circumstances, the District Judge properly held the tug in fault, and that the libelant was entitled to contribution. Decree affirmed.

(243 Fed. 861)

BURROUGHS ADDING MACH, CO. v. FELT & TARRANT MFG. CO.

(Circuit Court of Appeals, Seventh Circuit. April 10, 1917.)

No. 2255.

1. PATENTS 167(1)—CONSTRUCTION OF CLAIMS-LIMITATION BY DRAWINGS AND SPECIFICATION.

The claims of a patent are to be construed in the light of the real invention as shown and described in the drawings and specifications.

2. PATENTS 167(1)-CONSTRUCTION OF CLAIMS-LIMITATION BY DRAWINGS AND SPECIFICATION.

While courts will always endeavor to distinguish the several claims of a patent, one from another and give a broadly stated claim a broader construction than one more narrowly stated, this rule is subject to the fundamental and controlling rule that a patentee's broadest claim can be no broader than his actual invention as disclosed in his drawings and specification.

3. PATENTS 328-VALIDITY AND INFRINGEMENT ADDING MACHINES.

The Felt patents, No. 762,520, No. 762,521, No. 767,107, and No. 960,528, all for improved mechanism for adding machines, construed, and held valid, but not infringed.

Appeal from the District Court of the United States for the Eastern Division of the Northern District of Illinois.

Suit in equity by the Felt & Tarrant Manufacturing Company against the Burroughs Adding Machine Company. Decree for complainant, and defendant appeals. Reversed.

Infringement suit on four patents issued to Dorr E. Felt on calculating machines. The patents are numbered 762,520, 762,521, 767,107, and 960,528, dated, respectively, June 14, 1904, June 14, 1904, August 29, 1904, and June 7, 1910. A reargument was directed by the court, and argument had June 9, 10, and 15, 1916. A rehearing was granted and argued March 10, 1916.

For other cases see same topic & KEY-NUMBER in all Key-Numbered Digests & Indexes

Edward Rector and Robert H. Parkinson, both of Chicago, Ill., for appellant.

Henry Love Clarke, of Chicago, Ill., for appellee.

Before MACK and ALSCHULER, Circuit Judges, and SANBORN, District Judge.

SANBORN, District Judge. These patents are for improvements on adding machines, for which Felt had taken out earlier patents expiring before this suit was begun. The chief question is whether the mechanism employed by defendant, different from that illustrated by the patents in suit, is an infringement. The improvements covered by the patents are many of them meritorious and valuable, and give the machine much greater flexibility and rapidity of action than the earlier forms. As to most of the improvements the Burroughs Company has sufficiently departed from the patented form to escape infringement, but as to one of them, particularly, there is question.

The principle of action of an adding or calculating machine is not difficult to understand, but there is much complication in the actual machine. Aside from the recording of results on paper, and restoring the machine from one operation so that another may be begun, known as "clearing the machine" or canceling the former operation, an adding machine depends on three points. These are: (1) The use of the numeral-wheel and column-actuator; (2) the carrying mechanism, by which the turning of the units wheel beyond a full revolution carries one to the next wheel, and so on through a hundred, a thousand, ten thousand, etc.; and (3) the employment of stop mechanism to prevent the wheels from overrunning, and thus turning up a greater number than the one struck.

The Numeral-Wheel Mechanism. On the periphery of the numeralwheel the digits 1 to 9 and the cipher are printed, and there are nine keys, marked 1 to 9. When a key is depressed the wheel will turn up to view the number which the key bears. Thus if the 6 key is touched the number 6 will come up, and if then the 2 in the same bank or column is touched the number 8 will appear, each key having the ability to turn the wheel that many tenths of a revolution corresponding to its own value. Depressing the 3 key turns the wheel three-tenths around, the 8 four-fifths, etc. If the 9 is struck and then the 1 the wheel will complete one revolution, and turn up the cipher. All this is accomplished by the relation of the key bars to the column-actuator and the numeral wheel, as shown by the accompanying cut, being plaintiff's Comparative Drawing No. 22, which needs only the number keys to give a clear idea of the latest form of calculating machine. With a bank of keys over each column-actuator the picture would be complete; but it may readily be understood that if the keys are so placed that they can depress the column-actuator, number 1 key being nearest the wheel and number 9 farthest away, the same depression of the latter may be made to depress the actuator 9 times as far as the former, since 9 is near the fulcrum of the actuator and 1 is farthest away.

Carrying Mechanism. When a column of figures is added with paper and pencil the tens, hundreds, etc., are carried from the units, tens, etc., columns. The same thing must be done mechanically in an adding machine by turning the tens wheel one-tenth of a revolution every time the units wheel makes a full revolution, two-tenths when it makes two revolutions, etc. In this way the values of all the operated keys are added in one common sum or total upon the series of numeral-wheels. When the units wheel completes a revolution the tens wheel moves forward one step, two steps when it completes two revolutions, and there is the same result in respect to the tens and hundreds, hundreds and thousands, etc., for as many banks of keys as the machine has. This carrying operation is brought about in the Felt construction by a ratchet and pawl construction, and in defendant's by a planetary gear. This is the point at which the main question of infringement comes up, the defendant claiming that it makes use of different means and operation.

The following figures will serve to illustrate plaintiff's carrying devices. Figure 5 is taken from the Felt patent 366,945, and 5a from appellant's brief.

The snail cam shown in different positions in both figures is attached to the hub of all the numeral-wheels except that of the highest order. When a lower order wheel completes a full revolution its cam, turning counter-clockwise, pushes out the pawl M', registering with the next higher wheel, by means of its shoulder m2, into the position shown by Figure 5a, and when the tail of the cam clears the rear end of the

shoulder the spring operates on the pawl and rotates the higher order. wheel one step, so that the figure 1 will show on the higher wheel and the cipher or some figure between that and 9 on the lower. Thus the carry is made, no matter what keys of the lower order wheel may be operated.

To illustrate this carrying operation suppose the 9 key in the units column is struck 12 times so that the sum will be 108. On the first stroke the units wheel turns nine-tenths of a revolution, and the tens wheel does not move because its pawl M' has not yet been actuated by the units wheel cam and the tens wheel pawl spring. But when the 9 is struck again the units wheel revolves another nine-tenths, and turns up an 8, and the carry has been made so as to move the tens wheel one step, and show 18 on the top of the two wheels. When the third stroke is made the units wheel will show 7 and another carry occurring the tens wheel will show 2. So with each successive stroke the units wheel goes nearly around, and the tens wheel advances one step until the eleventh, where it remains stationary because the units wheel was then starting as at the beginning with the cipher uppermost; but when the twelfth stroke is made the units wheel cam and the tens pawl move the tens wheel one step, and the tens wheel (having now completed one revolution) has by its cam and the hundreds wheel pawl operated on the hundreds wheel to move it one step, so that the final result of all the strokes on the 9 key is 1 on the hundreds wheel, a cipher on the tens and an 8 on the units, or 108.

A novel improvement on this carrying device, covered by claim 29 of the first patent in suit, No. 762,520, presents the chief question in the case, and will be explained after adverting to the third point, the stop mechanism.

The Stop Mechanism. The third requisite of an adding or calculating machine is to provide automatic catches or stops to prevent overrun of a wheel. Without such stops the rapid striking of a key might rotate the wheel so far as to produce an unauthorized carry. Thus if 99 was simultaneously struck in the units and tens columns both wheels might overrun so as to make a carry in both the tens and hundreds wheels, and show a total of 110 instead of 99. The most important of these stops operate on the column-actuators, and will be referred to later.

Improvement in Carrying: Claims 29 and 30. Referring to the cuts 5 and 5a it may be seen that there would be a loss of carry if, when the carry is being made, both the lower and higher order wheels are moving. As described by plaintiff's counsel:

"The thousands wheel might at one and the same time be receiving both an impulse from a key of its own and an impulse from the carrying mechanism of the hundreds wheel; and if there were not some special means for preserving both impulses the lesser or carrying impulse might be swallowed up in the greater or key-driven impulse that such thousands wheel was receiving."

The patentee refers to this feature as follows:

"In order to prevent the loss or swallowing of the carrying movements in the other and generally larger movements of the numeral-wheels received from