Vischer Products Co. v. National Pressure Cooker Co.

71 F. Supp. 973, 73 U.S.P.Q. (BNA) 214, 1947 U.S. Dist. LEXIS 2637
CourtDistrict Court, W.D. Wisconsin
DecidedApril 24, 1947
DocketCivil Action 1310
StatusPublished
Cited by8 cases

This text of 71 F. Supp. 973 (Vischer Products Co. v. National Pressure Cooker Co.) is published on Counsel Stack Legal Research, covering District Court, W.D. Wisconsin primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Vischer Products Co. v. National Pressure Cooker Co., 71 F. Supp. 973, 73 U.S.P.Q. (BNA) 214, 1947 U.S. Dist. LEXIS 2637 (W.D. Wis. 1947).

Opinion

STONE, District Judge.

This is an action brought by plaintiff against defendant for infringement of Claims 6, 7, 8, 9 and 10 of Patent No. 2,301,724 issued to plaintiff on November 10, 1942, on application dated May 18, 1938.

The claims in issue, set forth in the margin, are for alleged improvements in pressure cookers and a pressure relief device. 1

Defendant denies the validity of the said claims and their infringement.

Pressure cooking is an old art. It is a method of preparing food in a closed vessel, from which air has been expelled, and in which steam pressure is generated from a source of heat. By increasing the pressure in a cooking container, the temperature inside the vessel can be raised beyond the usual boiling point of water, 212° F. A desirable and commonly used pressure in pressure cookers is fifteen pounds per square inch. At that pressure a temperature of 250° F. can be reached within the container. Cooking food at this tempera *975 ture in a pressure cooker requires a much shorter period of time than ordinary cooking, avoids oxidation of the food and is alleged to preserve vitamins, minerals and food values ordinarily lost in other methods of cooking.

The pressure relief device disclosed in the patent in suit is a synthetic rubber plug' which seals an aperture in the cooker cover under ordinary cooking pressures. When an excessive pressure, which may be predetermined, is reached, the rubber device is distorted by the pressure, the portions of the plug seated around the aperture being pulled away therefrom, and the plug is expelled, opening the hole in the cover and releasing the excess pressure. If it is blown out it may be reinserted in the cover for further use.

Plaintiff first sold its pressure cooker with the Vischer pressure relief plug in 1938. Thereafter, in 1944, it learned that defendant was using on its pressure cooker as an auxiliary pressure relief device a short metal tube screwed into an aperture in its cooker cover, at the top of which tube the metal was cut away to form an overhanging lip or seating surface, over which was placed a synthetic rubber cap having in its interior a flange which engaged the underside or seating surface of the metal lip. Under excessive pressure, the cap would be distorted, pulling the flanges away from the seating surface. The cap would then be blown off, opening the aperture and releasing the pressure. This plug is marked Exhibit No. 27.

In October 1944 defendant commenced the manufacture of a pressure relief valve in a second and different form. In this form an aperture is made in the cooker cover on the inner side of which are formed little ears or lugs. A synthetic rubber disc, larger than the aperture, is inserted between the ears and the aperture. When pressure is built up within the cooker, the disc is forced upwardly so that its outer edges seat against the surface of the cover around the aperture, sealing it. When excessive pressures are produced, the disc becomes distorted, the edges pulling away from the seating surface around the aperture, and the disc is forced through the hole in the cover, opening it and relieving the pressure. This plug is illustrated in Exhibit No. 29.

On discovery of the alleged infringement and prior to the commencement of this action, notice was sent by plaintiff to defendant, charging that both forms of defendant’s device infringed plaintiff’s patent.

In this action, Claims 6, 8 and 10 of the patent in suit, No. 2,301,724, are charged to be infringed by defendant’s first form of structure. Exhibit No. 27. Claims 6, 7, 8, 9 and 10 of said patent are charged to be infringed by defendant’s second form of structure, illustrated in Exhibit No. 29.

The pressure relief devices of both plaintiff and defendant are made of Neoprene, a synthetic rubber, which was not invented by plaintiff but was known to the art as early as 1931, when it was then foreseen that it could be used as a resilient product in the manufacture of “diaphragms”, “valves” and “valve discs”. Both plugs are designed to blow out and do blow out at a pressure in excess of thirty pounds. The plugs can be made from either natural or synthetic rubber, but synthetics such as “Duprene”, “Neoprene” and “Perbunan” are claimed to be preferable because of their alleged superior resistance to oils, greases, heat and oxidation.

There is no evidence in this record that any pressure cooker was ever sold or used without a pressure escape device. It does appear from the evidence that prior to the application for the patent in suit, all pressure cookers offered to the public were equipped with an auxiliary pressure escape valve in addition to the service valve that was intended to operate at a higher pressure than ordinary cooking pressure. The auxiliary pressure relief devices then and now in use included the ball and spring service valve, the gravity type valve and the fusible plug. In the ball and spring device the ball is held in place over a hole in the cover by the tension of two springs, and blown from its seat by excessive pressure. The gravity type valve is simply a weight over a hole, without springs, that operated by gravity. The fusible plug was, prior to 1938, and is now extensively used in pressure cookers. It is a practical and an efficient plug. It is a metal plug inserted in the cover of the cooker and has a *976 core of soft alloy metal that melts when the temperature gets high enough, opening a hole in the cover to release excess pressure. There is no proof in the record that any of the foregoing plugs failed to operate under excessive pressure. Both temperature and pressure affect the release of either a fusible or rubber plug.

Defendant makes several objections to the validity of the claims in suit; namely, that the claims are invalid for want of invention over prior art; that they are invalid because of their functional limitations without adequate, full, clear and concise descriptions as prescribed by R.S. Sec. 4888, 35 U.S.C.A. § 33, and that they are drawn to an exhausted combination.

Plaintiff relies much upon the presumption of validity. However, the presumption is no stronger than the facts upon which it is founded. The facts do not support this claimed presumption. The Examiner in the Patent Office rejected all of Vischer’s claims as showing no invention over Weil, Carlsson and Nelson. Representations of fact were made to the Board of Appeals that are not found in this record.

Vischer represented to the Board of Appeals that it was not and is not unusual to read of injuries, sometimes fatal, from explosions of pressure cookers; that these explosions made it necessary for manufacturers to secure insurance “at high premium rates” to protect themselves against claims arising out of such accidents; that by virtue of his invention the hazard incidental to the use of pressure cookers had practically disappeared so that insurance can be obtained at a nominal premium rate. There is no evidence in this record about insurance rates, and no witness has identified by name or address, any person as having suffered injury or damage as a result of operating a pressure cooker equipped with a pressure relief device. The plaintiff’s brief filed with the Board of Appeals contained the language:

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71 F. Supp. 973, 73 U.S.P.Q. (BNA) 214, 1947 U.S. Dist. LEXIS 2637, Counsel Stack Legal Research, https://law.counselstack.com/opinion/vischer-products-co-v-national-pressure-cooker-co-wiwd-1947.