Frederick A. Mosby

Biography
Fred, born Frederick Anderson Mosby on October 24, 1924, is a native of Morgantown, West Virginia¹. In 1943, at age nineteen, Fred joined the U.S. Navy and was sent to the Great Lakes Naval Training Station in Chicago for boot training. From there he went to Hampton Institute in Hampton, Virginia for training to become an Electrician. After completion of the Electrician course Fred was retained as an instructor. He taught for awhile and was then selected for officer's schooling.

Fred's selection for officer training enabled him to pursue studies at the University of Rochester in Rochester, New York. In 1947 he graduated, earning a Bachelor of Science degree in Mechanical Engineering and was commissioned an Ensign in the Naval Reserve. From 1948 to 1952 Fred worked as a Mechanical Design Draftsman for the Electric Storage Battery Company in Philadelphia, Pennsylvania.

In 1952 Fred Mosby joined the General Electric Company in Schenectady, New York as Electrical Designer in the Aeronautic and Ordnance System Division. In 1955 he transferred to the Incandescent Lamp Department in East Cleveland, Ohio.

Fred married twice. His first wife, Dorothy M. Gaffin, passed away at a relatively early age. Together they had three children, two girls and one boy. Fred married a second time, to Julia I. Jones. They were blessed with two sons. He passed away on June 26 2018 at the age of 93.

The Invention of the Halogen Lamp
The use of halogens in lamps was trialled as early as 1882 by Edwin A Scribner of the United States Electric Lighting Company, who patented a chlorine-filled lamp which was not successful. The idea was picked up again in 1892 by John Waring of the Waring Electric Company, who patented his Novak Lamp as a circumvention of the Edison patents. As the name implies this lamp contains no vacuum, but has a smal pressure of bromine inside the bulb. This was also not successful - probably the bromine had very little effect. Although it was declared that Waring's lamp was still in violation of the Edison patents, he escaped closure as the Edison patent itself expired in 1894 - after which his company reverted to vacuum lamps.

The next noteworthy attempt to use a halogen occurred in the early 1950s following the formation of a small group, for the purpose of developing a heat lamp, at the General Electric lighting headquarters of Nela Park, in E. Cleveland, Ohio. The group was under the leadership of Alton Foote. The lamp, which was to be used for drying purposes, was to have a small diameter outer envelope of fused quartz instead of the traditional larger reflector type bulb. A marked difference between the reflector type of bulb and the quartz bulb is that the quartz can withstand much higher temperatures. During operation it is possible for the quartz to become red hot.

Linear quartz heat lamps were made in the laboratory but sometimes it was found that they would blacken. One of the workers in the group was Elmer G. Fridrich. Fridrich's assignment to that group resulted in an unforseen benefit to the lighting industry that was to be realized many months later. Elmer had read about a refining process for exotic metals in a chemistry and metallurgy magazine; the process utilized a halogen cycle. For about six months the similarity of the refining apparatus and a vertically burning quartz heat lamp continued to intrigue Elmer. One day, after the chores of the workday had been completed (that is, following the making of a certain number of heat lamps), Elmer asked Al Foote if he could pursue an idea that he had; the idea was to put some iodine in the lamp to determine its effect. Permission was granted, and Elmer then consulted with some of the older technical personnel, including Carl Kenty. It was during these consultations that Elmer learned that halogens had been tried in (carbon filament) lamps before. At least two patents had been granted, as mentioned above. As a result of these consultations it was decided to proceed with the idea to add iodine to some lamps.

One of the engineers at that time was William F. Hodge. Bill was nearing retirement and in his laboratory he had an unused vacuum system that was offered to Elmer for lamp processing. In addition to allowing Elmer to use his vacuum system, Bill supplied Elmer with tubulated clear quartz heat lamps which had tungsten supports. Another colleague, Mary Jaffe, supplied Elmer with iodine. At that time Elmer had no experience in "tipping off" lamps and so he approached another colleague and friend, Emmett H. Wiley, who did have the necessary experience in tipping off lamps from a vacuum system. The stage was now set for the first quartz tungsten filament halogen lamp to be made with a measured amount of iodine. Unlike many initial attempts at invention, this one was to be, in Elmer's own words, "A howling success." The promise of a workable lamp seemed assured. It was to be found out later, however, that short lamp life was experienced. It became clear that additional investigations were required in order to result in a product that was consistent in its performance.

One of the key members in the engineering group who helped establish the necessary lamp design and manufacturing equipment for the dependable operation of the iodine cycle was Fred Mosby.

It was found during the investigation of blackening that impurities in the tungsten wire played a role. In the case of iodine lamps Mosby said¹:

"Because oxygen, as part of the iodine cycle, is required for it to operate, it is essential that a quantity of oxygen is available throughout life of the lamp. Tungsten impurities, if not controlled, form stable oxygen compounds that deplete oxygen thus causing the lamp to blacken. It is very difficult to control oxygen and impurities in the iodine cycle lamp."

Fred participated as a co-worker with Ed Zubler, helping to determine satisfactory iodine and oxygen levels as well as the tolerable wire impurity levels. In addition, he participated in the design and development of other halogen lamps. Developments such as these are often result of combined efforts of several individuals. Unlike the more usual effort of one individual in days past, synergism is the key to success today.

After working as a process engineer, Fred then did design work and later was Manager of Quartzline Engineering. He then became Manager of Special Incandescent Engineering and after that became a Consultant on incandescent lamps. He retired from the General Electric Company in January, 1990.

Fred Mosby was granted eight U.S. patents that pertain to the incandescent lamp; seven of these relate to the tungsten-halogen lamp. These patents are listed in the section below.

The First Halogen Lamps
It's of some historical interest to identify the first halogen lamps that appeared for public use. The following is the response received from Fred¹ regarding that question:

"The first tungsten halogen lamps sold were 45-watt, 6.6-ampere lamps used to pinpoint capital cities on the world sphere at the 1960 World's Fair in New York City. Of course the number of lamps sold was rather small. However, the first halogen lamp sold in large quantities was the 28-volt, 150-watt aircraft wing tip marker. The lamp was designed and produced in the Large Lamp Department for a short time for the Miniature Lamp Department which had design and production responsibility for aircraft lighting. Stan Ackerman was the design engineer from Miniature Lamp who had responsibility for wing tip lamps. Thus, Large Lamp produced the lamp, but it was sold by the Miniature Lamp Department."

From a review of Mosby's patents it is interesting to note that he was also the inventor of the now ubiquitous recessed contact base, known as the type R7s. The first commercial halogen lamps described above by Mosby are believed to be the types 1958 and 1959, which exmployed complex end terminals made from folded metal strips to serve as the electrical and mechanical interface between the lamp and its luminaire. It would have been expensive and cumbersome to apply a similar interface for mass-produced lamps for general lighting. Thus Mosby's development of the compact, simple and low-cost recessed base cannot be underestimated in simplifying and further stimulating the tungsten-halogen business. Indeed the same type of base has since been adopted for a broad variety of double-ended metal halide and high pressure sodium discharge lamps.

The Halogen A-Line Concept
One project Fred undertook on his own was to develop a tungsten-halogen lamp that could be mounted inside an A-line bulb. Such a lamp would provide improved light output and life when compared with the common household lamp. The structure design in Fred's U. S. Patent No. 3,243,634 is shown below. Details in the patent drawing that are of no interest here were deleted from the drawing. The glass bulb was made thicker in the event the pressurized halogen lamp should ever rupture.

Of interest, of course, is the performance difference between a typical A-line, or household lamp, and the high pressure halogen lamp discussed here. Such a comparison was made in the patent description and it follows:

"Thereby, as compared to conventional household lamps operating at, for example, about 16 lumens per watt for 750 hours in the popular 100 watt size, lamps of the halogen-cycle type may be operated at efficiencies of, for example, 20 to 25 lumens per watt for a life in excess of 2000 hours and with virtually no depreciation in light output during life."

Management made the decision not to market the lamp at the time, apparently because of its high cost. Another reason for not marketing the lamp was the fact that compact fluorescent lamps, with their higher efficacies were being considered. Additionally it is believed that at the time of this patent, there were still considerable problems associated with the implementation of high voltage and low wattage incandescent coils in halogen atmospheres.

Eventually GE did market a lamp based on Mosby's principal, in the form of the GE Performance-Plus Halogen launched in 1987. This was marketed as an energy-saving alternative to the incandescent lamp delivering the same luminous flux, with 2-3 times longer life. It is notable that the efficacy of the commercially developed models is considerably lower than that which was predicted in Mosby's original patent application, owing to the previously mentioned difficulties of achieving high performance from long-life high voltage and low power halogen lamps. The thick-walled glass envelope also made the lamp heavy and expensive. As a result, this lamp and others like it were not terribly successful.

The concept of a halogen capsule within an A-line lamp only became a real success following three refinements of Mosby's original idea. The first of these was perfected around 1983 by Thorn Lighting of England, which solved the problems associated with achieving long life and high efficacy from high voltage low power halogen lamps. The second challenge was overcome in 1987 by Philips Lighting of the Netherlands, which solved the problem of end-of-life explosions of such halogen capsules and enabled the use of thin-wall soft glass envelopes as used on ordinary incandescent lamps. This brought the price of such halogen lamps down to the level that consumers could afford. The final hurdle was not overcome unti around 2004 by Osram GmbH of Germany, which was the first to raise the efficacy of this kind of lamp such that it approached the levels foreseen in Mosby's original patent on the concept. Thus it required the combination of the ideas of four competing manufacturers developed over a period of three decades to bring Mosby's idea to commercial readiness. This enormous investment of effort may help to paint a picture of just how complex the challenges were, and enable the reader to understand why GE was not in a position to capitalise on Mosby's original idea at the time of its invention. Perhapas regrettably, the original patent had expired long before the time these additional refinements were achieved.

Acknowledgements
The writer appreciates the information and comments given Fred Mosby regarding this major advance in the performance of the incandescent lamp. Fred Mosby kindly supplied his photograph, which is appropriate for the time of his lamp work.