Radio Broadcast (Nov 1926-Apr 1927)

20 RADIO BROADCAST NOVEMBER, 1926 the famous anecdote, "You may doubt, if you will, whether the church can damn you; but if the judge says hang, you hang." You may doubt, if you will, whether the Langmuir patent on extra-high vacuum in a tube is a true invention at all; but if the United States Circuit Court of Appeals ultimately says that it is, you will thereafter make or sell such a tube at your peril of jail for contempt of court. ALMOST EVERY PATENT HAS ITS DAY IN COURT THAT example is only one of the hundreds of possibilities involved in the scores of important patent cases now pending in the Federal courts. Nearly every known method of accomplishing radio reception is patented by at least two rival claimants for the exclusive use of that method; and really every article of apparatus is similarly involved in an undecided lawsuit. Most people suppose that the Armstrong regenerative principle is the most strongly intrenched invention in radio, yet De Forest has recently attacked it head-on in the Federal Courts. De Forest was once almost universally believed to have blanketed the tube situation with his patent of the three-element tube, yet to-day De Forest is in legal dfficulties in the manufacture or sale of tubes. A dozen manufacturers are making neutrodyne sets under the Hazeltine patents, yet Hazeltine is being sued by the Armstrong licensees on the theory that his neutrodyne circuit involves regeneration, while, from exactly the opposite direction, he was sued by the Radio Corporation on the theory that his neutrodyne circuit did not involve regeneration and therefore infringes Rice and Hartley's neutralizing methods. This situation is brought about by the technical complexities in the construction and use of the radio-frequency amplifier. The most complicated patent situation of all surrounds the vacuum tube. There are 256 unexpired patents in this field alone covering everything from the relation of the grid to the plate, on to such details as the use of thorium in the making of a tungsten filament, and the various methods of exhausting the air and gases from the bulb. It would be hopeless to attempt to review all the important radio patents and their tangles in an article like this. The most condensed available statement of them occupies forty-two closely printed pages of the 1923 report of the Federal Trade Commission on the "Radio Industry" — and that statement gives only one side of the story and nowhere near all the details. A SUMMARY OF THE "KEY" RADIO PATENTS FOR present purposes, we shall have to be content with a summary view of half a dozen patents that now seem to be "key" patents, controlling various types of receiving sets. The tube is "the heart of the set," and perhaps the biggest battles of the hour are raging around the tube. Dr. Irving Lang muir, of the General Electric Company, filed an application in the Patent Office thirteen years ago, to cover his claim that he invented the idea of using an exceptionally high vacuum to increase the efficiency and lengthen the life of the tube. H. D. Arnold, of the Western Electric Company, made a similar improvement, and these two conflicting applications have been involved in what the Patent Office calls "interferences" ever since. Independent observers insist that the idea and the practice of high vacuum tubes are as old as the tube itself, and the Western Electric Company claims that it is not an "invention" at all — but, Photograph by R. H. Marriott U. S. RADIO PATENTS This stack of patents includes those which have been issued between the years of 1871 and 1924, more than two thousand in all. The picture shows, at the foot of the patents, one of DeForest's first "audions" beside a silver dollar piece. The "audion" has been the cause of some of the costly litigation in radio history. With so many patents, covering every branch of the subject, it is no wonder that decisions concerning patent rights are only arrived at after prolonged legal fray. The stack of patents illustrated is about two feet eight inches high as noted above, the Circuit Court of Appeals will settle the question some day, and its decision will be law. It could easily put all but one tube manufacturer out of business. Another tube patent of vital importance is the Coolidge patent, claiming to cover the thoriated tungsten filament. Ordinary tungsten filament soon crystallizes under incandescent heat, and breaks. The addition of thorium considerably lengthens the life and increases the efficiency of the filament. The Coolidge patent covers a practical method of drawing thoriated tungsten wire, and claims to cover the use of such wire. The General Electric Company, owner of the Coolidge patent, has a test case against De Forest pending in the District Federal Court in Delaware. Here, again, a court decision can put all but one manufacturer out of business. Passing from the tube to the circuit, we come first upon Armstrong's patent covering regeneration. The courts have decided that this invention dominates the vacuum tube oscillator and the regenerative circuit. Armstrong licensed twenty concerns under this patent before selling it to the Westinghouse Electric Company. This patent is about the most securely adjudicated in the whole radio field, but, as remarked above, De Forest has recently attacked it. The various forms of grid leaks are covered by patents issued to De Forest, and Langmuir. The last named is broad enough, if sustained by the courts, to control this feature absolutely. It is owned by the General Electric Company. THE IMPORTANT NEUTRALIZATION PATENTS NEUTRALIZED circuits are covered by patents issued to Hazeltine, Rice, and Hartley. Fourteen licensees are manufacturing sets under the Hazeltine patent. Rice is a General Electric inventor and Hartley an American Telephone & Telegraph (closely associated with the Western Electric Company) inventor. A battle royal is waging here between Hazeltine, independent, and the Radio Corporation as licensee under all General Electric and Western Electric radio patents. The Radio Corporation sought to affirm the Rice and Hartley patents in a suit against the Twentieth Century Company in the Federal Court for the Eastern District of New York; while Hazeltine sought to affirm his patents in a suit against the Electrical Service Engineering Corporation in the Federal Court for the Southern District of New York. The first action by R. C. A. against the Twentieth Century Company was decided in favor of Hazletine. The action by Hazletine and his licensees against the Electric Service Engineering Corporation was also won by Hazletine. Doubtless these cases will ultimately go to the Federal Circuit Court of Appeals. The Hazeltine patents are also involved in a suit against A. H. Grebe & Company. Here, again, it is possible that the final court decision could rule out of the field all but one patentee. There are two or three other patents of great present importance, but enough has been said above for our immediate purpose. First, it should be observed that the critical patents today are not the critical patents of a few years ago. With the rapid advance of the art, the control of a basic idea does not rest in the basic patent, but rests in the patent upon some more recent refinement of