Foxboro Co. v. Taylor Instrument Companies, Civil Action No. 1034.

• Court: United States District Courts. 2nd Circuit. United States District Court of Western District of New York
• Writing for the Court: BURKE
• Citation: 58 F. Supp. 313
• Parties: FOXBORO CO. v. TAYLOR INSTRUMENT COMPANIES.
• Decision Date: 16 November 1944
• Docket Number: Civil Action No. 1034.

58 F. Supp. 313

FOXBORO CO.
v.
TAYLOR INSTRUMENT COMPANIES.

Civil Action No. 1034.

District Court, W. D. New York.

November 16, 1944.

58 F. Supp. 314

John B. Bean and Edwin T. Bean, both of Buffalo, N. Y. (Blair, Curtis & Hayward, Edward G. Curtis, and Charles C. Ladd, all of New York City, of counsel), for plaintiff.

Frederick R. Twelvetrees, of Buffalo, N. Y. (Cooper, Kerr & Dunham, Drury W. Cooper, and Allan C. Bakewell, all of New York City, of counsel), for defendant.

BURKE, District Judge.

This suit is for the infringement of three patents; Mason reissue No. 20,092; Bristol reissue No. 19,944 and Bristol No. 1,624,887, all owned by the plaintiff. The Mason patent covers a mechanism for automatic control of industrial processes involving temperature, humidity, flow, pressure, liquid level, chemical concentration and the like. Prior to Mason's invention there was no controller capable of automatically controlling difficult multi-capacity manufacturing processes, i. e., the maintenance of some condition of the process at a desired point or within certain desired limits by regulating some variable affecting the condition of the process, usually by means of a feed valve. Between the years 1920 and 1930 the simple "batch" process of manufacture was gradually being replaced by complex continuous methods of manufacture. With the advent of multi-capacity processes such as fractionating towers in the oil refining industry, process control began to present troublesome problems. Available controllers which had proved adequate for comparatively simple manufacturing processes were inadequate. Automatic control of such processes had baffled engineers and inventors and make-shifts of various sorts in the form of control aids were resorted to which left much to be desired in the way of control. The controller industry had failed to solve the new problems of automatic control. Application for the original Mason patent No. 1,897,135 was filed on September 15, 1930.

Mason's invention was a new combination of elements and principles long known

58 F. Supp. 315

to the controller industry. The principles of proportioning control and proportioning-plus-reset control had long been known but had not been successfully applied to control problems in many important industries. Unlike the simple on-off controller which causes the feed valve to either completely open or close, the action of a proportioning controller causes the feed valve to modulate its corrective action proportionally to the extent of the deviation of the process from the desired point of control. But this control is not enough on multi-capacity process where fresh demands are made on the process. The process will not return to its original control point, because to get increased flow it must be below it. Reset control supplies the deficiency. It keeps the feed valve operative as long as the process is deviated from the control point. Prior to Mason the only proportioning and proportioning-plus-reset controllers available on the market required powerful measuring elements to exert a force to operate the control mechanism. Such applications were limited in their use to the control of pressure and speed. The majority of such applications were in power plants and steel mills. None were available for controlling temperature, humidity or chemical reactions. Mason's controller was the first proportioning controller and the first proportioning-plus-reset controller that could be universally applied to all types of process. It could operate with low-power measuring elements because the measuring element was not required to exert and balance a force. Such low-power measuring elements were available for measuring all types of process conditions

Mason's invention embraces a measuring element sensitive to the condition being controlled (temperature, pressure, etc.) with a free end movable to positions corresponding to the value of the condition being controlled, a nozzle-flapper pilot valve supplied with a restricted flow of air which detects and responds to changes of position of the measuring element, a relay valve responsive to the pressure back of the nozzle and controlling the air supply to and waste from the power-exerting mechanism of the controller, a pressure-fluid-operated diaphragm motor with a movable end mechanically connected to move the nozzle and pneumatically connected with the output of the relay valve to maintain the nozzle tangent to the flapper. The output pressure of the relay valve is the pressure in the diaphragm motor and is also the output power-exerting pressure of the controller to operate any convenient type of valve motor regulating flow effecting the condition being controlled. Thus in operation the movements of the measuring element are caused to be followed by a proportioning motor through the agency of a pilot valve that detects the position of the measuring element and operates a relay valve which so regulates the supply of air pressure to the motor that the motor moves to follow exactly the movements of the measuring element. The pressure operating the motor is proportional to the position of the measuring element. In addition to this proportioning controller thus far outlined Mason provided a mechanism for reset action operated in opposition to the proportioning motor, consisting of another diaphragm motor counteracting the proportioning motor. The controlled pressure in the system is transmitted to the interior of the reset motor through a length of capillary tubing providing a retarded flow of air to permit a gradual change in the pressure within the reset diaphragm. The operation of the reset mechanism provides for throttling the feed valve as it approaches the control point and constitutes a balancing mechanism establishing a control balance at a definite point of control. There is always a tendency to establish equal pressures in the proportioning and reset motors through the capillary tubing. The combination permits a definite control point regardless of varying demands of the process being controlled.

The defendant contends that the Mason patent is invalid for lack of sufficient disclosure in that the specifications and drawings do not meet statutory requirements. 35 U.S.C.A. § 33. It must be remembered (the defendant points it out in the brief) that all of the instrumentalities used by Mason were old and well-known. It was the new combination of well-known elements that Mason claimed. There was no need to disclose the details of instrumentalities well known. United Chromium, Inc. v. International Silver Co., 2 Cir., 60 F.2d 913. Diaphragms, bellows, relay valves and the use of levers were common in the controller art prior to Mason's invention and their characteristics were well-known. Mason's invention did not go to the details of any of these basic elements.

58 F. Supp. 316

The defendant points out that the Mason patent drawings neither show the spring characteristic of Mason's diaphragms nor is it described in the specifications. But this characteristic and its part in the operation of the controller are made evident in the patent specifications for one skilled in the art and familiar with the use of diaphragms in common use as applied to prior commercial controllers and disclosed in many prior patents. The operation of Mason's controller as described would make it sufficiently clear that such operation could not take place without the inherent spring characteristic of the diaphragms either built in the diaphragms themselves or having the diaphragms opposed by external springs. For instance the Mason specifications discussing the operation of the controller as a proportioning controller point out that "pressure in diaphragms 39 and in the system is always directly proportional to the position of the flapper." If the diaphragms did not have a spring characteristic any pressure in the diaphragms would cause them to fully expand. To engineers skilled in the art, the drawings, specifications, and claims made it sufficiently evident that diaphragms with spring characteristics were intended although not specifically mentioned or described and that the controller could operate in no other manner. Inherent performances characteristic of known structures disclosed in a patent need not be described in the patent specification. Bickell v. Smith-Hamburg-Scott Welding Co., 2 Cir., 53 F.2d 356

Foxboro's commercial controller, Model -10 Reactor, embodied all the elements of the proportioning controller and the same arrangement of the elements as disclosed in the Mason patent. The operation of this controller as demonstrated at the trial showed that it operated in the manner disclosed by the Mason patent. The measuring element used in this controller is a conventional spiral Bourdon tube similar to the helical measuring element shown in the Mason patent. Instead of using the restriction provided in the hollow valve stem of the relay valve as shown in the Mason patent, the commercial instrument provided an outside tube for the restricted air supply. This, however, was merely a mechanical adaptation for simplification of manufacturing and did not change the operation as disclosed in the patent. The proportioning bellows of the commercial instrument is the equivalent and performs the same function as the diaphragms shown in the patent. Other band-shifting mechanism is provided in the commercial instrument but this mechanism performs the same function and is the equivalent of that shown in the patent, the change in the commercial instrument being to accommodate the mechanism to a round instrument case. Likewise the manner of adjusting the width of the proportioning band in the commercial instrument is the equivalent of the arrangement shown in the Mason patent.

Foxboro's proportioning-plus-reset controller, the Stabilog, embraces all the elements of the Reactor and adds the reset bellows and capillary tubing. The operation of...