Legal Opinion
Magnaflux Corporation v. Coe
Court of Appeals for the D.C. Circuit
Decided December 20, 1943No. 8359PublishedCited by 10 opinions
1Opinion of the Court
EDGERTON, Associate Justice.
Appellant seeks to patent a method and means for detecting flaws in steel by magnetism. Both the Patent Office and the District Court rejected the claims for lack of invention.
Appellant admits that the elements of the scheme are old. It was known that steel can be tested by magnetizing it and sprinkling it with para-magnetic particles. The particles were known to adhere over any minute crack or sub-surface defect. The use of alternating current for magnetizing purposes was known. Hauser showed that the breaking of the circuit at the zero point would produce maximum…
2Cases cited7 opinions
- Cuno Engineering Corp. v. Automatic Devices Corp.Supreme Court of the United States · 1942
- Marconi Wireless Co. v. United StatesSupreme Court of the United States · 1943
- Marconi Wireless Telegraph Company of America v. United StatesSupreme Court of the United States · 1943
- Abbott v. CoeCourt of Appeals for the D.C. Circuit · 1939
- Kirsch Mfg. Co. v. Gould Mersereau Co.Court of Appeals for the Second Circuit · 1925
2 more not listed; retrieve them via the Exa API.
3Cited by10 opinions
- Kwikset Locks, Inc. v. Hillgren. Hillgren v. Kwikset Locks, Inc.Court of Appeals for the Ninth Circuit · 1954
- Standard Oil Development Co. v. Marzall, Commissioner of PatentsCourt of Appeals for the D.C. Circuit · 1950
- Application of Jack H. HofstetterCourt of Customs and Patent Appeals · 1966
- Besser v. OomsCourt of Appeals for the D.C. Circuit · 1946
- National Lead Co. v. KingslandDistrict Court, District of Columbia · 1948
5 more not listed; retrieve them via the Exa API.