Hall Signal Co. v. General Ry. Signal Co.

169 F. 290, 94 C.C.A. 580, 1909 U.S. App. LEXIS 4582
CourtCourt of Appeals for the Second Circuit
DecidedMarch 16, 1909
DocketNo. 241
StatusPublished
Cited by3 cases

This text of 169 F. 290 (Hall Signal Co. v. General Ry. Signal Co.) is published on Counsel Stack Legal Research, covering Court of Appeals for the Second Circuit primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Hall Signal Co. v. General Ry. Signal Co., 169 F. 290, 94 C.C.A. 580, 1909 U.S. App. LEXIS 4582 (2d Cir. 1909).

Opinion

COXE, Circuit Judge.

This is an equity action for the infringement of letters patent No. 470,813 granted March 15, 1892, to Adoniram J. Wilson, assignor to the complainant, for an improvement in automatic electric block signals for railways. The application was filed November 9, 1891, which must be regarded as the date of the invention.

The drawings represent, diagrammatically, the invention applied to a series of seven blocks on a line of railway, the sections varying in length to meet the requirements of different railways. The intermediate blocks—those between the first and the seventh as shown—may be duplicated indefinitely. The specification describes, by reference to the drawings, the successive operation of a train upon the signal devices in passing over the track sections represented. In the preferred arrangement shown in the drawings it is intended that each alternate signal shall be merely a cautionary signal which the engineer may pass but he does this with notice to look out’ sharply for the next signal. The intervening signals are absolute signals, which he should never pass except when they stand at safety, and if they do not clear before him he must stop until they do. In the broad invention the rail circuits are normally closed and the signaling circuits are normally open at a circuit closer which is constructed to be closed by the action of the train upon one of the rail circuits. The signaling circuit' is also capable of being broken by one or more normally closed circuit breakers which are constructed to be opened by the action of the train on one or more., of the next succeeding rail circuits of the line.

The claim involved is as follows:

“1. In a block signaling apparatus, the combination, with a series of normal-ly-elosed rail-circuits, of a series of normally open or broken signaling-circuits,. [292]*292each signáling-cireuit including a normally-open circuit-closer constructed to be closed by the action of the train upon one of the rail-circuits and also including a normally-closed circuit-breaker constructed to be opened by the action of the train upon the next succeeding rail-circuit of the line, substantially as and for the purpose set forth.”

It is a combination claim for a block signaling apparatus, having the following element's:

(1) A series of normally closed rail circuits.

(2) A series of normally open signaling circuits.

(3) Each signaling circuit including (1) a normally open circuit closer, constructed to be closed by the action of the train upon one of the rail circuits and also including (2) a normally closed circuit breaker constructed to be opened by the action of the train upon the next succeeding rail circuit of the line.

The defense is that the claim, if broadly construed, is invalid in view of the prior art, and, if limited to the device shown and described, is not infringed.

The patent relates to the so-called normal danger system as distinguished from the normal safety system, it being contended that the patentee was the first to make the former a safe, reliable, simple and workable system—having marked advantages over the systems of the prior art.

The record presents' such a- wilderness of irrelevant matter that it is not easy to deduce therefrom a perfectly clear understanding of the respective advantages and defect's of these rival systems. We understand, however, that the normal danger system is equipped with nor- . mally open signaling circuits so arranged that the force which sets the signal at safety never operates except when a train is approaching. .The signal is held by gravity in the position indicating danger so long as no trains are present and is sent to safety by the on-coming train.

• Under the normal safety system, when the engine driver approaches a block the semaphore at the entrance is in an inclined position by day • and shows a green light by night indicating that the track ahead is clear and that he may safely proceed unless the signal rises to a horizontal position, or shows a red light. In other words he is to assume that the track ahead is clear and safe until the contrary appears by the appearance of a danger signal.

The normal danger system, on the contrary, always shows a red light at night and a horizontal semaphore by day, indicating danger; ..the safety signal appearing only on the approach of a train and when • the block to be protected is clear. In the first system the assumption is that all is safe ahead till “danger” appears, and, in the second, that .all is unsafe ahead until “safety” appears.

In the one, if there be no movement of the signals, the engine driver keeps on, in the other, unless there be movement of the signals, he .stops.. To quote from the pamphlet said to have been written Iw the president of the defendant:

“Consistency argues that all the signals shall indicate danger, except where they are cleared for the passage of a train.”

From the viewpoint of safety it seems to us that the preponderance of evidence is clearly in favor of the complainants’ system. If, through [293]*293climatic or other influences, the signals cease to operate' it seems obvious that it is much safer that they should clog in the danger rather than in the safety position. In the one case the failure of the signal to operate might result in the unnecessary stopping of-a train, in the other it might result in a rear-end collision. It is not at all improbable that laymen may give greater weight to this feature of the system than practical railroad men, but it' seems to us that an improvement which reduces, in any degree, the chances of derailment and collision, and thus safeguards life and property, is entitled to greater consideration than one which deals only with economics.

We do not intend to intimate that the Wilson system does not, from a practical point of view, compare favorably with the normal safety plan. Quite the contrary appears. As the electric current is in operation during the comparatively short time that the signal stands at clear it is obvious that there is very much less consumption of battery material. As one of the witnesses points out, the expense of maintenance increases only in proportion to the amount of use, whereas in the normally clear system the expense is greatest when apparatus is least used. Scientific men, versed in the art of railway signaling had early recognized that the logic of the situation was all with the normal danger theory. Thus, in 1842, Sir William Cooke writes:

“I think it highly desirable that the ordinary or quiescent condition of the station signal should be a state of danger, and not a state 'of safety, so that a train should never run into a station without special guaranty that it was prepared to receive it.”

This was before the days of automatically controlled block signaling but it shows that early in the art of railroading it was recognized that the ideal position of the signal was one indicating normal danger. The difficulty was not with the theory but with the means to make the theory practicable. This was an easy task when applied to a manually operated system but the record shows that its practical application to an automatic system was obstructed by impediments which it was found impossible wholly to remove, although many skillful and scientific men were at work on the problem. At the date of Wilson’s invention, in 1891, the art of railway signaling was in an embryonic condition.

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169 F. 290, 94 C.C.A. 580, 1909 U.S. App. LEXIS 4582, Counsel Stack Legal Research, https://law.counselstack.com/opinion/hall-signal-co-v-general-ry-signal-co-ca2-1909.