611 F.2d 156 (6th Cir. 1979), 77-1444, Hanson v. Alpine Valley Ski Area, Inc.

Docket Nº:77-1444.
Citation:611 F.2d 156
Party Name:204 U.S.P.Q. 803 Alden W. HANSON, Plaintiff-Appellee, v. ALPINE VALLEY SKI AREA, INC., Defendant-Appellant.
Case Date:December 18, 1979
Court:United States Courts of Appeals, Court of Appeals for the Sixth Circuit

Page 156

611 F.2d 156 (6th Cir. 1979)

204 U.S.P.Q. 803

Alden W. HANSON, Plaintiff-Appellee,


ALPINE VALLEY SKI AREA, INC., Defendant-Appellant.

No. 77-1444.

United States Court of Appeals, Sixth Circuit

December 18, 1979

Argued June 5, 1979.

Page 157

Peter P. Price, Price, Heneveld, Huizenga & Cooper, John F. DeWitt, Grand Rapids, Mich., Julius Tabin, John F. Flannery, Fitch, Even, Tabin & Luedeka, Chicago, Ill, for defendant-appellant.

Bernd W. Sandt, Midland, Mich., for plaintiff-appellee.

Before LIVELY and MERRITT, Circuit Judges, and BROWN [*], District Judge.

BAILEY BROWN, District Judge.

This is an action alleging patent infringement, and the patent alleged to be infringed is a process for making snow for winter sports. The plaintiff below, appellee here, is Alden W. Hanson (Hanson), who is the inventor and patentee of the patent. The defendant below, appellant here, is Alpine Valley Ski Area, Inc. (Alpine). Alpine's defenses are that the patent is invalid and that, in any event, it is not infringed by Alpine, as is alleged by Hanson, in using snow-making equipment purchased by it from Hedco, Inc. (Hedco). 1 The case was tried before District Judge James Harvey who filed findings and conclusions to the effect that four of the claims of the patents are valid and that three of these were infringed.

It appears that there has been a great increase in winter sports in recent years but that, even in the northern parts of the United States, there is frequently a shortage of snow. This has created a need for snow making at winter sports locations.

In 1954, a patent was issued to W. M. Pierce, Jr., no. 2,676,471 (the "Pierce, Jr. 471 patent"), which claims a method of making snow to meet the needs of winter sports, particularly for skiing. In general, this patent teaches a method whereby a parallel system of two pipes, one carrying compressed air and one carrying water under pressure, is placed alongside a ski run. The water and the compressed air concurrently fed to a series of fine nozzles which emit the combined compressed air and water, the expanding air creating a sufficient decrease in temperature to convert the water into snow. This system, or variations of it, has been used extensively but it has drawbacks, one of which is the tendency of the nozzles to freeze up and thereby become inoperative and another of which is the substantial capital investment necessary for the installation of such a system.

In 1961, the patent in suit was issued to Hanson (no. 2,968,164, the "Hanson 164 patent"). It claims a method of making snow that does not require a system of pipes and does not require compressed air. In general, this patent teaches that snow can be produced if, with the ambient temperature at or below 30 degrees F, a large volume of air is produced, as with a motor driven propeller, and water is projected into this fast-moving stream of air. The preferred embodiment, as set out in the specification, is to place a concave cup on the hub of the propeller and to project the water countercurrent to the air into the cup as a deflector with the result that the water splashes into drops in front of the propeller. The drops are carried by the airstream and are then cooled, become snow, and are deposited as such. The patent also teaches that the use of dirty water or water mixed with crushed ice increased the snowmaking capacity of such equipment because the dirt and ice particles act as nuclei and aid in crystallization of the water drops. So using crushed ice is included in the description of the preferred embodiment. Finally, the patent teaches that the apparatus for making snow is movable as needed.

Page 158

The process of freezing water is more complicated than commonly understood. Essentially it involves the removal of heat energy from water. However, when the temperature of water is brought down to the freezing point (32 degrees F), a barrier is reached in that a great deal more energy must be removed to reduce the temperature by one degree than is necessary to reduce it by one degree when the temperature is higher than 32 degrees F or to reduce it by one degree (after it is frozen) when it is below that point. Further, water will not freeze at 32 degrees F unless "nucleation" occurs. This was, as has been indicated, recognized to some extent by the specification of the Hanson 164 patent, though nucleation was not fully understood at that time. Nucleation initiates the solidifying process and, to create ice, the presence of a nucleating agent in each particle of water is required. Minute clay particles can act as nucleating agents, and minute ice particles, whether introduced as such or whether formed spontaneously when the temperature reaches -40 degrees F, will also act as nucleating agents. In the process taught by the Pierce, Jr. 471 patent, nucleating agents can be clay particles in the water or can be ice particles formed spontaneously by the sharp reduction in temperature caused by expansion of compressed air. On the other hand, in the process taught by the Hanson 164 patent, nucleating agents can be clay particles in the water or ice particles mixed with the water. Moreover, when the method taught by the preferred embodiment of the Hanson 164 patent is used, spontaneous nucleation will occur in the vortices of air at the tips of the propeller, extremely cold temperature being created there by air expansion. Snow cannot be made, of course, unless the water is finely divided into drops from which heat is removed and in which nucleation occurs.

The trial court held that claims 1, 2, 5 and 6 of the Hanson 164 patent are valid.

Claim 1 calls for:


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