Kuester v. Hoffman

152 F.2d 318, 68 U.S.P.Q. (BNA) 35, 1945 U.S. App. LEXIS 4492
CourtCourt of Appeals for the Seventh Circuit
DecidedDecember 20, 1945
DocketNo. 8846
StatusPublished

This text of 152 F.2d 318 (Kuester v. Hoffman) is published on Counsel Stack Legal Research, covering Court of Appeals for the Seventh Circuit primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Kuester v. Hoffman, 152 F.2d 318, 68 U.S.P.Q. (BNA) 35, 1945 U.S. App. LEXIS 4492 (7th Cir. 1945).

Opinion

SPARKS, Circuit Judge.

Plaintiffs charged defendants with infringement of claims 1 and 2 of their United States Patent No. 2,152,699, issued to them April 4, 1939, on their application of October 8, 1934. The defense was non-infringement and invalidity. The court found the facts specially, and that the claims were valid but not infringed. It concluded as a matter of law that the claims were not infringed, and decreed accordingly on December 29, 1944. It made no conclusion of law, nor did it decree, as to validity. From this decree notice of appeal was filed March 27, 1945.

The invention relates to improvements in heating or cooling processes and systems, and claim 2 1 is the only one relied upon here.

One object of the invention is to provide a heating - system in which heat disseminating means is separated from a source of high heat, and the temperature in the radiator system is separated from the source of high heat and is modulated at intervals, as required, by the establishment of circulation between the radiator system and the source.

The other object is to provide a heating system wherein a circulating and radiating system is provided with means for maintaining a forced, and substantially constant circulation therein of heated fluid, in [319]*319combination with a storage tank or other source of heated fluid at a relatively extremely high temperature, and means whereby the storage tank or supply is normally divorced from the circulating and radiating system, but is connected with it by means of a by-pass controlled by a valve which may interconnect the circulating and radiating system and the storage tank, whereby to supply to the radiating and circulating system a charge of hot water from the storage tank to modify the temperature of the fluid in the circulating system.

The ordinary and well known heating system includes a source of hot water, a supply main to the radiator and a return line from the latter to the source. The patent modifies such system in the following respects, although all the elements are quite old in the art. It provides a by-pass from the return to the supply line without passing through the boiler; it divorces the boiler from the circulatory system by providing a normally closed control valve by which the boiler is connected to the system at intervals; it provides a power driven circulating pump in continuous operation for circulating the water of the system, inclusive or exclusive of the boiler, as determined by the control valve; and it controls the intervals of opening of such valve, independently of the heat demand in the space to be heated, by so organizing the thermostatic control of the valve that upon each opening of it, the thermostat will temporarily be subjected to an artificially high heat which results in the closing of the valve regardless of the temperature of the air in the space to be heated.

By thus assuring the closing of the control valve, regardless of room temperature, time is given for the “slug of hot water” to produce its effect in the space to be heated without a continuation of hot water from the boiler into the circulating water. If that “slug of boiler water” is adequate to satisfy the heat demand of the space to be heated, the valve will not reopen; if not adequate, after the artificial heat environment has been dissipated, the thermostat will again open the control valve to admit another “slug of hot water” to the system. It is said the system thus automatically tests the demand after an equalizing interval following each “slug of hot water.” However, the “slug” cannot be stopped or decreased after the valve starts to open, until it opens completely and closes again.

Under the patent the water is normally circulated by the pump through the pipes to and through the radiators and through the return pipes back to the pump. When the temperature in the room in which the thermostat is located falls below the point at which the thermostat is set, an element of the latter moves to the left and contacts the wire which energizes the motor connected to the control valve, which in turn causes the crank arm and plunger of that valve to move the valve plug so as to close the port which shuts off circulation through the by-pass and permits circulation through the storage tank, thus introducing water at extreme temperature into the circulating circuit for a predetermined period. The control valve is adjustable, hence the time consumed in one opening and closing of it is variable, dependent upon such preadjustment. Mr. Kuester testified that at one time he had observed it through several operations, when it opened and closed in forty seconds. He further stated: “I should say about fifty per cent of the time there would be * * * yes more than that * * * a commingling of the hot and cold joining because of the opening and rising and closing of the valve, and only very briefly would the hot water exclusively be admitted to the system.”

At the time when the thermostatic element contacts the wire which energizes the motor to the control valve, there is a resistance or heating element within the thermostat casing which becomes energized, thus generating heat inside the thermostat casing which causes the thermostatic contact element to shift from the motor energizing the wire to its opposite contact, thus establishing a circuit which moves the crank arm of the motor in the opposite direction, and closes the port of the control valve, thus permitting circulation through the by-pass but not through the storage tank. Thermostats of this type are admitted to he old in the art.

It is clear that in the operation of the patent, the control valve which admits hot water from the tank immediately reverses itself, when fully opened, to cut off the flow of hot water from the tank. The valve automatically opens about once in every four minutes, and automatically opens and closes in about forty seconds. Even though the system calls for heat, the valve continues to thus open and close until the heat requirements of the system are satisfied. However, when the valve has opened [320]*320and clqsed once, it cannot reopen until the heating element in the thermostat has cooled to below the room temperature, which requires two to three minutes.

In the accused device, the supply of heated water for the radiating circuit is controlled by an outdoor temperature bulb and the water temperature bulb located in the supply main to the radiator circuit. These bulbs are connected to a temperature controller so constructed as to call for a different temperature of water going to the radiator circuit as the outside temperature varies. For each outside temperature, water at a definite temperature must be circulated through the radiator circuit to offset the heat losses from the building, and the temperature controller is designed to vary this temperature of the circulating water in accordance with the heat requirements demanded by variations of the outdoor temperature.

In actual operation, the addition of hot water to the radiator circuit is controlled by a rocker arm which rests upon the top of the plungers of two bellows connected respectively with the outdoor and the water temperature bulbs, and controls the operation of the switch which in turn controls the opening and closing of the control valve.

The control valve consists of a heat motor having a casing on the inside of which is an accordion type bellows which operates on the top of the valve stem connected to the control valve.

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138 F.2d 875 (Seventh Circuit, 1943)
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Cite This Page — Counsel Stack

Bluebook (online)
152 F.2d 318, 68 U.S.P.Q. (BNA) 35, 1945 U.S. App. LEXIS 4492, Counsel Stack Legal Research, https://law.counselstack.com/opinion/kuester-v-hoffman-ca7-1945.