80 F.2d 912 (4th Cir. 1935), 3815, Hoeltke v. C.M. Kemp Mfg. Co.

Docket Nº:3815.
Citation:80 F.2d 912, 26 U.S.P.Q. 114
Party Name:HOELTKE v. C. M. KEMP MFG. CO.
Case Date:June 18, 1935
Court:United States Courts of Appeals, Court of Appeals for the Fourth Circuit

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80 F.2d 912 (4th Cir. 1935)

26 U.S.P.Q. 114




No. 3815.

United States Court of Appeals, Fourth Circuit.

June 18, 1935

On Rehearing Jan. 10, 1936.

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Appeal from the District Court of the United States for the District of Maryland, at Baltimore.

Frank Keiper, of Rochester, N. Y. (Robert R. Carman, of Baltimore, Md., on the brief), for appellant.

Arlon V. Cushman, of Washington, D. C., and Lewis W. Lake, of Baltimore, Md. (Cushman, Darby & Cushman, William M. Cushman, and C. Willard Hayes, all of Washington, D. C., on the brief), for appellee.

Before PARKER and SOPER, Circuit Judges, and HAYES, District Judge.

PARKER, Circuit Judge.

This was a suit instituted to enjoin infringement of patent No. 1,822,402 issued September 8, 1931, to William F. Hoeltke on an application filed April 6, 1929. Hoeltke, the patentee, was complainant. The defendant was the C. M. Kemp Manufacturing Company, of Baltimore, a corporation engaged among other things in the manufacture and sale of apparatus for mixing and distributing a mixture of air and gas for industrial purposes in factories. The complaint, in addition to asking damages for infringement of the patent and injunction against further infringement, prayed for an accounting by defendant of profits made on the sale of infringing apparatus prior to the grant of the patent, on the ground that defendant had obtained from complainant a disclosure as to the nature of the patent, and, in fraudulent breach of the confidence so reposed, had made and sold apparatus embodying complainant's invention and attempted to obtain a patent thereon. Defendant denied both the infringement and the fraud alleged, and pleaded in addition that the patent was anticipated in the prior art and was lacking in invention. The court below decided the issues so presented in favor of the defendant, and complainant has appealed.

The patent in suit covers an automatic fire check for use in connection with gas burners in such way as to prevent the ignition of the gas and air mixture in the pipe lines with consequent explosion and

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wrecking of the apparatus. Prior to complainant's invention, the only fire check in use consisted of a nipple, which contained a perforated refractory metal disk, and behind this a screen of copper wire gauze, and which was inserted between the end of the gas pipe line and the burner. This disk and screen permitted the mixture of gas and air to flow to the burner, but in case of backfire, arrested the flame and prevented its igniting the mixture of gas and air in the pipes for a considerable period. The nipple was painted with linseed oil and lamp black; and when a backfire occurred, the heating of the nipple caused these to give off an odor which warned the person in charge of the apparatus of the approaching danger, so that he could shut off the gas by means of a hand valve located behind the nipple. This fire check with the manually operated valve was satisfactory and sufficient if workmen were near when the backfire occurred; but, if no one was near enough to be warned by the odor, the flame burned through the disk and screen and ignited the gas and air mixture in the pipes, resulting in costly and dangerous explosions. The only other device in use for preventing backfires was the large 'backfire preventer' of the Kemp patent, which we shall describe later. It was located near the mixing machinery, and, while efficient in preventing the wrecking of the machinery by backfires, it did not prevent costly explosions in the pipe lines in cases where the backfire was allowed to burn through the fire check.

Complainant was a mechanic or millwright employed by the American Can Company in its plant in Brooklyn, N. Y., in which apparatus manufactured by defendant had been installed. An explosion resulting from a backfire occurred in that plant on April 24, 1928, which caused considerable damage and resulted in the shutting down of the plant for the day. Complainant made inquiry of an employee of defendant (through whom defendant later made application for patent covering complainant's invention) as to why defendant did not provide some device to prevent such occurrences, and was told by this employee that it was not possible to provide such device, and that if this had been possible, defendant would have provided it. Complainant thereupon went to work to evolve such a device and after a number of experiments invented an automatic valve to be used in connection with the fire check described. It consisted of a spring valve held open by a lever, which, in turn, was held in tension by a pin placed in front of the refractory disk of the old fire check. This pin was made in two parts and was fastened together by solder, or other fusible metal, so that a backfire would melt the fusible metal and cause the pin to part. This would release the lever, and the spring would thereupon close the valve. The figures and the pertinent part of the specification contained in the patent issued to complainant are as follows:

(Image Omitted)

'It sometimes happens that the flame of the burner strikes back through the burner into the line, and the flame will then burn at the refractory disk 15 and after a while this disk and nipple and the reducer will get hot enough so that the flame will strike back into the copper wire mat and will then melt out the copper and may even travel further back in the line and cause an explosion. To prevent this I perforate the reducer 10 at the top and bottom and pass through it a pin or rod 20, which pin is shown in Figure 3. This pin makes a close sliding fit in the reducer and is made with an enlarged head 21 at one end and is threaded at the lower end 22. The upper end 21 is forked and a screw passes through the forked end 21 and through the slot 6 in the end of the lever 5 and connects the lever and the pin together. The

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pin 20 is made of two parts which overlap each other and form a joint as indicated at 23 and the parts are soldered together at this place with a solder that has a rather low melting point. When the pin is in the position shown in Figure 1, a nut is placed thereon and screwed up to make contact with the reducer and hold the pin 20 so that the soldered joint 23 stands substantially centrally of the reducer 10. When the flame strikes back in the reducer, the solder quickly melts long before the refractory disk 15 can heat up and opens the joint in the pin 20. The spring in the valve housing 1 then expands pushing up the pin 2 and the lever 5 which is released by the melting of the joint 23 in the pin 20 and the value then closes thus shutting off the flow of gas upon which the flame at once goes out and the line cools off. This prevents any danger from fire or explosion, and also prevents the waste of gas.

'It will be understood that the brass rod 20 can be replaced by any metal having a low melting point, or a wood or vegetable fiber can be used that will quickly burn through.

'It will be seen that if a backfire occurs the flame will pass through the nipple 11 into the reducer 10, where for the time being the passage of the flame is arrested by the refractory element 15 at which point the flame will burn without passing through the element until the element has heated up. This takes some time, and during this time the flame is heating the soldered joint 23. This joint quickly reaches the melting point of the solder, and then the joint lets go and permits the valve to close. If the refractory element 15 were omitted the copper mat by itself would hold the flame in position to play on the soldered joint until the copper mat had heated up sufficiently so as to no longer cool the gas below the burning point. Thereafter the flame would gradually work its way through the copper mat, taking some minutes in so doing, but long before this could happen the soldered joint 23 would let go and permit the valve to close, thus cutting off the supply of gas and causing the flame to go out.'

The claims of the patent relied on in this suit are claims 1, 6, 8, 14 and 16. Claims 1 and 14 which may be taken as typical, are as follows:

'1. A safety gas cock for a gas line comprising a valve, a spring adapted to hold the valve closed, a lever adapted to normally hold the valve open against the spring, a pin adapted to hold said lever in position to hold said valve open, said pin extending into the gas line and being adapted to be separated intermediate its ends by a rise in temperature in the gas line, thereby releasing the lever and permitting the spring to close the valve.'

'14. A safety gas cock for a gas line comprising a valve and valve housing, a spring adapted to hold the valve closed, a lever pivoted on the housing, a pin extending into the housing between the valve and the lever, said lever being adapted to hold the valve open through said pin against the spring, a rod adapted to hold said lever in position to hold said valve open, the portion of said gas line between the rod and the valve having a flame check therein that will permit the gas to pass through it freely and will retard the passage of any flame that may get into the gas line, the lower end of said rod being located at the discharge end of said flame check and where it will be quickly heated by any flame burning thereon and being held in place in the gas line at normal temperatures by fusible material, which material will melt with a rise in temperature and release the rod and lever and permit the spring to close the valve before a flame can pass through the gas line from the rod to the valve.'

After complainant had perfected his device, he wrote defendant under date of December 4, 1928, calling attention to the explosion which had occurred...

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