Nash Engineering Co. v. Cashin

• Decision Date: 17 August 1926
• Docket Number: No. 1900.,1900.
• Citation: 13 F.2d 718
• Parties: NASH ENGINEERING CO. v. CASHIN et al.
• Court: U.S. Court of Appeals — First Circuit

13 F.2d 718 (1926)

NASH ENGINEERING CO. v. CASHIN et al.

No. 1900.

Circuit Court of Appeals, First Circuit.

July 2, 1926.

Rehearing Denied August 17, 1926.

Louis W. Southgate, of Worcester, Mass. (Charles T. Hawley, of Worcester, Mass., on the brief), for appellant.

Lynn A. Williams, of Chicago, Ill., and J. Lewis Stackpole, of Boston, Mass., (Ross O. Hinkle and Williams, Bradbury, McCaleb & Hinkle, all of Chicago, Ill., and Fish, Richardson & Neave, of Boston, Mass., on the brief), for appellees.

Before BINGHAM, JOHNSON, and ANDERSON, Circuit Judges.

ANDERSON, Circuit Judge.

In this patent infringement suit, the court below found no infringement, and dismissed the bill. The patent sued upon is the Jennings patent, No. 15,637, a reissue — on an application filed May 5, 1923, and issued June 26, 1923 — of No. 1,447,854, issued March 6, 1923, on an application filed June 15, 1917.

The patent covers a combination of old elements, and relates to a so-called wet vacuum heating system, through which a partial vacuum is established in the return pipes from the radiators in a steam-heating system. In outline, such a vacuum system consists of a low pressure boiler, in which the steam is developed; pipes connecting the boiler with the radiators; return pipes, trapped at their outlets, to permit the condensed steam, or water, to flow back; a tank or receiver for the returns of water and air; and pumps to create the requisite vacuum and to force the water back to the boiler.

In the early days of steam heating, the circulation was attained by pressure from the boiler. The vacuum system, by which the steam is drawn, instead of forced, through the pipes, was years ago found to give a more uniform and more easily regulated heat in the radiators, to lessen troubles with leaks in the system, and to be more economical.

In the earlier development of the vacuum type, reciprocating pumps were commonly used, but they were found unsatisfactory. The returns are made up of gritty water, mingled with air and other gases. Gritty water is obviously destructive of the ordinary reciprocating pumps; they wear, become noisy, and are expensive to maintain. To avoid these difficulties, various attempts were made to use rotary air and water pumps, but, for various reasons, without complete success, until Mr. Jennings made his invention, which was so successful that over 8,100 installations of his apparatus were made in about six years prior to the trial, which began in November, 1924. His claim that it has revolutionized the vacuum steam-heating art is, as the court below found, fairly supported by the evidence.

A sketch of the genesis of the Jennings invention and patent will be a convenient approach to the present problem:

About 1908, Jennings, who had been educated as a mechanical engineer, became connected with the Nash Engineering Company, which was then starting in a small way to develop the inventions of Lewis H. Nash, among which was a rotary air pump or compressor, using water for its pumping action. For this device Nash applied for a patent February 24, 1910; it was granted March 31, 1914, No. 1,091,529. This Nash rotary air pump or compressor is a wheel in an elliptical casing, partly filled with a liquid — in common practice, water, though mercury might probably be used. The wheel is divided by radial plates, thus making buckets or displacement chambers. When the wheel is rotated rapidly, the resultant centrifugal force carries the water outward towards the periphery of the wheel, so that, as the wheel passes the longer diameter of the ellipse, the inner portions of the opposite displacement chambers are left void, and then, as these displacement chambers approach the smaller diameter of the casing, the water is forced back, filling the displacement chambers. Inlet ports or apertures are so placed that air will be drawn into the partially emptied chambers as they pass the longer diameter of the ellipse, and be forced out on the other side of the pump through outlet ports, as the chambers fill with water in passing the shorter diameter of the ellipse. The water in these displacement chambers thus operates like a piston in the ordinary pump. The result is that, as the pump whirls very rapidly, the air is drawn in on one side and forced out on the other side, and the pump can be used either as a suction pump or as a compressor for air. On this record, it is not an efficient pump for water.

In 1913 or 1914, Jennings undertook to put this pump to use in a wet vacuum steam-heating system. He found, as his evidence shows, that the chief difficulties with the pumps then in use were that they wore, became noisy, and also required too much power to operate. At about that time electrical motors were coming into common use for such purposes. One of his chief objects was to reduce the amount of power required. Jennings found that, in the returns in a vacuum system, the air was in a much larger proportion than the water; that the water came intermittently or in slugs, while the air required practically constant pumping. He testifies that, under the methods then in use, the practice was to "discharge both air and water against boiler pressure"; that it occurred to him that, if he could develop a unit which would have the air pump relieved of the discharge head, there would be a substantial resultant economy and efficiency. He accordingly experimented with combining on a single shaft, electrically operated, two pumps — a centrifugal water pump and the Nash air pump. He attained an operative device of this combination in 1915; but he had trouble with the operation of his centrifugal pump, in that it would become "air-bound" when there was no water for it to pump. But in 1917 he overcame this difficulty by connecting the water pump with the tank, some inches above the bottom, so that the tank always retained sufficient priming water. Details of the priming arrangement are not now material. The general result was success. His invention is well described in the language of his original application, filed, as above noted, on June 15, 1917. In the specification he says:

"This invention relates to a wet vacuum pumping apparatus. The object of the invention is to provide an apparatus in which the air and water are separated, and the air exhausted by means of a pump and delivered into the atmosphere; the water being withdrawn by a separate pump and discharged against any desired pressure. Automatic means may be provided whereby the operation of the pumps is controlled according to the vacuum or the quantity of water returned, or by both. * * * Briefly stated, my apparatus comprises a receiver into which the returns of air and water are discharged, the water collecting in the bottom and the air in the upper portion of the receiver. A pumping unit is provided, which comprises a centrifugal water pump and a hydro-turbine air pump. The latter is connected to the top of the receiver, to exhaust the air from the same and discharge it into the atmosphere. The water pump is connected to the lower portion of the receiver, and withdraws the water from the latter and discharges it where desired. Means are provided whereby the operation of the water pump is controlled by the quantity of water in the receiver, and the operation of the air pump is controlled by the air pressure in the receiver."

After a lengthy description of the apparatus, with references to the accompanying drawings, and a detailed statement of the functions performed by each part of the combination, the specification ends as follows:

"Although I have described a specific arrangement of the receiver, pumps, and piping, it is very apparent that my invention is not limited to the particular embodiment shown and described, but that the details thereof may be varied within wide limits; the only requirement being that there shall be a receiver for the returns, a water pump and an air pump each separately taking its respective fluid from the receiver." (Italics supplied.)

This sentence simply emphasizes what otherwise appears in the drawings and description of the apparatus found in the specification and in the account there given of the method of operating the apparatus, as well as in all the claims made in the original application. In this original application were 11 claims, the first of which may, for present purposes, be taken as typical of all and is as follows:

"A water and air pumping system, comprising a receiver for air and water, a pump for withdrawing water from said receiver, and a second pump separately connected to said receiver for withdrawing air therefrom."

In every one of these claims both pumps are referred to as pumping from the receiver — the centrifugal pump taking the water from the receiver to the boiler, and the hydro-turbine or Nash pump the air from the receiver. The original specification, the drawings, and all the claims excluded any pumping of the returns into the tank. Nothing could be clearer than that the applicant provided that all the pumping of the returns was to be done after they had flowed into the tank.

This patent had a long and rather stormy passage through the Patent Office. Most aspects of the matters there in controversy have no bearing on the present issues. The Examiner originally disallowed most of the claims, on the Mohn patent for a condensing apparatus, No. 1,005,997. There was an appeal to the Board of Examiners in Chief, and an elaborate argument, mainly on the contention that the substitution of the Nash pump for reciprocating pumps, together with other elements, all old, entering into efficient combination, involved invention. The applicant contended that, "in the few years in which the apparatus of the patent * * * has been in use over 5,000 plants have been installed in the United States alone." Presumably the argument of commercial success went far to convince the Patent Office that Jennings had made a real invention. During...