Majority — Holmes J.
Syllabus
CERTIORARI TO THE CIRCUIT COURT OF APPEARS FOR THE SIXTH CIRCUIT.delivered the opinion of the court.
These are bills in equity brought by the petitioners to restrain the infringement of Letters Patent No. 589342, issued to- the assignee of Edward J. Dolan, and dated August 31, 1897. The patent was held invalid by the Circuit Court of Apeals for the Sixth Circuit. American Lava Co. v. Steward, 155 Fed. Rep. 731 and 740; S. C., 84 C. C. A. 157 and 166. It had been sustained by the Circuit Court of Appeals for the Second Circuit, Kirchberger v. American Acetylene Burner Co., 128 Fed. Rep. 599 ; S. C., 64 C. C. A. 107 , and a writ of certiorari was . granted by this court to the first-mentioned Circuit Court of Appeals.
The-patent, so, far as it comes in question here, is for a tip for acetylene gas burners and for the process of burning acety
A few words as to the conditions and knowledge at the time of the alleged invention will help to make the discussion plain. Acetylene gas began to be produced on a large scale for commercial purposes about 1895. It is very rich in carbon, and therefore has great illuminating power, but for the same reason coupled with the relatively low heát at which it dissociates and sets carbon free, it deposited soot or unconsumed carbon and soon clogged the burners then in use. It was possible to secure a complete consumption of carbon by means of the well-known Bunsen burner. This consists of 'a tube or cylinder pierced on the sides with holes for the admission of the air, into one end of which a fine stream of gas is projected through a minute aperture and from the other end of which it escapes and then is burned. A high pressure is necessary for the gas' in order to prevent its burning back. The ordinary use of the Bunsen burner is to develop beat and to that end a complete combustion of course is desired. But with an immediately complete combustion there is little light. The yellow light of candles and gas jets is due to free particles of carbon at a red heat, but not yet combined, with oxygen, or, as we commonly say, consumed. On the appearance of acetylene gas inventors at once sought to apply the principle of the Bunsen burner with such modifications as would produce this result. In doing so they found it best to use duplex burners, that is, burners the outlets of which were inclined toward each other so that the meeting of the two streams of gas formed a flat flame, and to let in less air.
In this state of things Dolan filed his application on February 18, 1897. The object was said to be “to provide'a burner the use of which will result in perfect combustion of the gas and the production of a flame which will afford the greatest
1 The following are copies of Dolan’s Fig. 1, and Fig. 2.
In the new specification, however, it was said that the operation 'seems to be’ that the gas draws in on all sides an envelope of air through the .openings a, &c., so far stating the Bunsen principle, but adding that “the result of this arrangement seems to be to so cool the outside,of the flame as to prevent any deposit of carbon at the point of egress.” And another paragraph was as follows: “The structure of my burner is such that if all of the burner were cut off in a horizontal plane, immediately above the outlet C [the point where the gas enters the upper chamber] the general shape and condition of the flame would not be modified, but in this case an immediate combustion would occur at the outlet. Under the conditions of this burner the point where the gas reaches its kindling temperature is carried upward, but the general shape of the escaping gas body is not materially modified.” It was stated earlier that “the result here accomplished would not be accomplished in an ordinary air-mixing burner in which the air was mingled generally with the body of the gas,” and that “in my burner an absolutely unobstructed passage is provided for the escape of the original jet' of gas formed by the constricted opening C. By reason of this fact it is substantially necessary to have two jets if a flame of considerable candle power is desired.”
The claims allowed and in controversy here are as follows:
“1. The process of burning acetylene gas, which consists in projecting a small cylinder of gas, in surrounding the same with an envelop of air insufficient to cause combustion of all the gas, and in finally supplying the gas with an additional amount of oxygen by allowing the stream of gas to expand
above the burner-tip into contact with the air, thereby burning the same, substantially as described.
“ 2. The process of burning acetylene gas, which consists in projecting toward each other two cylinders of acetylene gas, in surrounding the same with envelops of air insufficient to produce combustion of all the gas, and in finally causing the cylinders of gas to impinge upon each other and produce a flat flame, substantially as described.
“3. The combination in an acetylene-burner of the block. A having-the minute opening C, the cylindrical opening É, opening without obstruction to. the atmosphere, and the air-passages a, substantially as described.”
The ground upon which these claims are maintained is the theory indicated in one of the passages that we have quoted, to the effect that the gas emerges to the air surrounded by a mainly unmixed flow of air carried with it from the cylinder containing the holes a, a, and that this so cools the outside of the flame as to prevent a deposit of carbon. If this theory is not true and if all there is to the Dolan tip or burner is to provide for a mixture of air with the gas in the cylinder sufficient to secure complete combustion-of all that is burned near the point of emergence, but insufficient to bum all the gas, the patent must fail. For this latter contrivance-was well known, and if the shortness of the Dolan tip, which we are about to mention, has no other effect than to diminish the amount of ■ air received it does nothing new. Moreover, unless the theory ' of the cooling envelop so dominates the specification as to explain what is doubtful and ambiguous in it, the claim would not be for what now is said to be the characteristic of the Dolan tip. The characteristic of the Dolan tip now is said to lie in the fact that the cylinder is very short, as, it is said, it must be for it to be true that the shape of the flame would not be modified by cutting it off. The shortness of the cylinder is supposed to prevent .the mixing of the air and to produce the result desired.
But this theory of cooling not only is disputed in the testi
As we have said, the only passage indicating, even by indirection, the length of the cylinder, if that does, is the paragraph stating that if the burner were cut off the general shape and condition of the flamé would be the same, which is thought to reproduce more exactly a suggestion in Dolan’s specification as to a funnel shaped flame, said by him to result from the issue of gas with pressure through a small opening. But if the relative shortness of the cylinder had been understood to be an essential thing the patent naturally would have said so. • It is suggested that the shortness is implied by the word tip in the patent, but the patent equally is said to relate to an improvement in burners, and the length of burners depends on. the principle-involved. In fact, all that directly bears upon length is the statement, which we have not. yet mentioned, that the contracted opening for the gas into the cylinder is at or near the longitudinal center of the block constituting the tip. As the block may be longer or shorter, with no limits fixed, while the cylinder extends from the longitudinal center to the outlet
If, as now is said, á rat-tail flame is the mark of Dolan’s burner, the words “funnel shaped” in the original application were not apt to describe it, and did not purport to indicate a test. They were used merely to show, how the perfect combustion was achieved which is the declared object throughout. The cause assigned was not peculiar to Dolan’s tip. The amendment, in the passage as to the unaltered shape of the flame when the burner is cut off, goes on to say that ‘ of course ’ the shape, though cylindrical as it issues from the round hole, increases in diameter, ‘approximating in some degree to the form of an inverted cone.’ This of. itself almost excludes the notion that the rat-tail shape is the test, and no reader would draw that or any similar notion from the specification as a whole.
The patent was held void below on the further ground that it had been anticipated. We turn to this last because the question is complicated with .the theory that we have mentioned. If the Dolan patent had unreservedly committed itself to the notion of a cooling envelope with a contrivance made very short' for the purpose of securing that result, the argument in defense of it would be that the leading earlier patents proceeded upon the opposite theory of mixture and admitted, if
Decrees affirmed.
Mr. Justice McKenna dissents.
Cases cited
- Railway Co. v. Sayles 97 U. S. 554 p. 168
- Eagleton Manufacturing Co. v. West, Bradley & Carey Manufacturing Co. 111 U. S. 490 p. 168
- Kennedy v. Hazelton 128 U. S. 667 p. 168
- De La Vergne Refrigerating Machine Co. v. Featherstone 147 U. S. 209 p. 168