During the second half of the nineteenth century the fast expanding small craft industry developed a need to replace steam engines with cheaper and lighter machines. This led first to the use of natural (city) gas as engine driving fuel. However, since natural gas was not available everywhere, it was desirable to replace it in turn with liquid fuels which could more easily be transported in containers. As early as in 1838, William Barett, an English engineer and the German Siegfried Marcus experimented with primitive surface evaporators, to make a gas out of heated kerosene. Their purpose was to replace natural gas with kerosene engine fuel. These experiments met with little success. Surface evaporators could only be used with stationary engines, because they were bulky, and the heating of kerosene represented a constant fire hazard, especially so on moving vehicles.
The famous original gas engine of Lenoir (1860) as perfected by August Otto and Eugene Langen, resulted in the first four-stroke engine. These engines were fueled exclusively by natural gas.
In 1883, John Csonka’s 3 HP gas engine was patented. It could use either natural gas, or kerosene. Although this was a four-stroke engine, it eluded the still valid patent of Otto, by using an ingenious link-disk combination instead of the 2 : 1 gear ratio specified in the Otto patent.
In 1886 Csonka and Donát Bánki, both excellent designers, started a joint effort to improve gas engines. At this time Csonka had already designed and built several engines, including a greatly improved model, built in 1879. All their joint inventions were published under the name of „Bánki-Csonka.” This sequence of names was used for alphabetic reasons only.
Several gas engine designers have tried unsuccessfully to develop a system which could replace the dangerous and bulky surface evaporator used in those days. Csonka and Bánki were also working hard to find a solution to this problem. On a spring evening in 1890, after a tiring day at the Technical University in Budapest, Hungary, the two good friends walked to a nearby coffee-house. On one street corner Csonka caught sight of a flower-girl who sprayed her flowers with water, using an air blowing atomizer, operated by a rubber bulb. Csonka pointed to the girl and exclaimed: „Look at that girl! There is the solution! We should feed the liquid fuel into the engine, atomized by air flow!”
Then he stepped up to the girl, gave her a large bill and said: „I want no flowers, I only wish to remunerate you for the idea you have just inspired in me.” Wiht those words the two friends left the astonished flower girl, and entered the coffee house.
There they immediately drew a sketch of a liquid fuel atomizer on the white marble table. This time they did not read the newspapers, as they normally would have, but hurried back to the University. Working late into the night, the first design of the carburetor was created. Csonka machined and mounted it on their newly built kerosene engine. The engine started up at once, and ran on kerosene, fed only through the carburetor, without the use of a surface evaporator. Thus, in the summer of 1890, the carburetor was born. The first model of the carburetor had the peculiarity that its float was not made of a tinned plate, but of solid cork.
Although the first carburetor was fully operational by the summer of 1890, according to the documents quoted below, the two friends did not apply for a patent until February 11, 1893. Their application might have been delayed even further, had an unexpected event not taken place the day before, on Feb. 10, 1893. On that day Pál Lázár, professor at the Technical University in Budapest, delivered a public lecture on the topic of „Farm Engines”, and in the course of his talk he described the Bánki-Csonka atomizing carburetor. This unexpected turn of events forced the two inventors to act at once to protect their rights. Accordingly, the patent application was submitted in great haste, the very next day. The Hungarian patent was issued on May 3, 1894, 10891/1893.
Csonka was an extremely modest man and did not care much for publicity, thus for a long time the invention of the atomizing carburetor did not appear in the technical literature. However, it just so happened that not much later the German Daimler company’s famous chief engineer, Wilhelm Maybach, also designed an atomizing carburetor. There is no evidence to suggest that he obtained this idea from the work of Bánki and Csonka. It appears that he re-invented the device independently. When Maybach applied for a German patent, his request was rejected, because the patent office already knew about the Bánki-Csonka carburetor. In order to receive at least some patent coverage, despite the German rejection, Maybach applied for a French patent on August 17, 1893. This time he did manage to receive a patent, No. 232 230, since the French patent office in those days did not carry out any preliminary investigation of existing foreign patents before issuing a French patent. This patent had, of course, little practical value.
It is a fact that the Bánki-Csonka patent had six months and six days priority over the Maybach patent. Furthermore, the first Bánki-Csonka carburetor was built long before the inventors applied for the Hungarian patent. An article by Dr. P. Vajda, edited by the publishing house of the Hungarian Academy of Sciences, quotes Oscar Glatz, a former foreman of Csonka who was still alive in 1941: „By the autumn of 1891, the carburetor was completed after a year and a half of experimentation and preparatory work, including the carburetor’s float valve chamber and the float-valve control.” He was able to pinpoint the time as the autumn of 1891, since it was then that Oscar Glatz was called up for military service. By then, with the carburetor completed, the two inventors turned their attention to improving the ignition system (Their new system was the patented ignition tube, designed to replace the flame ignition system used in those days, which represented a major fire hazard).
It is also a fact that Maybach employed a petrol dropping apparatus with his first carburetor, while in the Bánki-Csonka invention the float secured a constant fuel level. It is clear, therefore, that the Bánki-Csonka device not only had priority, but was of a superior design. In spite of this, in most of the technical literature available today, including the majority of reference volumes, W. Maybach is listed as the inventor of the carburetor.
Maybach himself, however, was fully aware that the Bánki-Csonka patent had priority over his, and in a letter to Bánki he acknowledged this fact.
More recently, in a document dated October 7, 1982 and addressed to Albert B. Csonka, son of John Csonka, the Deutches Museum in Munich, Germany, which owns an original Bánki-Csonka carburetor, also confirmed the world priority of the Bánki-Csonka atomizing carburetor.
On November 30, 1896, the two Hungarian inventors also applied for patent protection for their carburetor in the United States. As a result the United States Patent Office issued patent 595, 552.
During the next century or so, the carburetor was greatly improved, but in spite of these modifications all carburetors in the world today still operate in the manner originally conceived by Bánki-Csonka. The so-called „Micro-Carburetor” was one of the most significant improvements of this kind, patented some 80 years after the original invention. It is interesting that its inventors, in turn, were the two younger sons of John Csonka.
The first model of the Bánki-Csonka atomizing carburetor (pulverizer) is now preserved at the National Museum of Science and Technology in Budapest, Hungary. It was on display at the 1958 World’s Fair in Brussels and many other fairs.
In conclusion, it should be noted that the word „carburetor” does not correctly reflect the operation of the device. It was derived from the French word „carburateur”, originally used to describe the heating equipment of early steam-engine driven vehicles. A more appropriate name would be „atomizer”, because the carburetor’s main function is to deliver to the engine a mixture of air and atomized liquid fuel, i. e. one in which tiny fuel droplets float in air. Indeed, in Hungary where the first carburetor was made, it is still called „porlasztó”, meaning pulverizer, because that was the name given to it by its inventors.