Arnold Zähringer

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Arnold Zähringer (born May 9, 1869 in Furtwangen ; † January 1, 1942 in Stuttgart ) was a technician and operations manager at Robert Bosch in Stuttgart. He was the inventor of the magneto for high-speed engines, what was then known as the rotating sleeve magneto.

Professional life and magneto ignition

After completing an apprenticeship as a mechanic , Arnold Zähringer joined the “Robert Bosch Workshop for Precision Mechanics and Electrical Engineering”, Rotebühlstrasse 75 B in Stuttgart, founded by Robert Bosch in 1886 .

After an interlude a. a at Siemens he returned after approx. 15 months (August 10, 1890) back to Bosch.

Robert Bosch knew that he could entrust Arnold Zähringer with his company when he was visiting customers. In addition to Zähringer, the workforce consisted of a total of 10 men, consisting of 6 assistants, two apprentices , including Gottlob Honold (who later became director) and two house servants .

Since 1890 Arnold Zähringer has also worked on the engine ignition in order to achieve improvements for high-speed engines. His goal was to produce an everyday ignition for high-speed motor vehicle engines. In 1892 the company, which was now called the "Mechanical Workshop and Institute for Electrical Engineering", suffered a bad setback. From a total of 24 people and one apprentice, Robert Bosch had to fire 22 employees with a heavy heart. Only the mechanics Richard Schyle, Arnold Zähringer and the apprentice Gottlob Honold could stay. Soon more jobs came in and people were hired again. In the back house workshop for precision mechanics and electrical engineering in the new Stuttgart location, Zähringer tried out everything possible and the new apprentice Max Rall was also allowed to help.

There was a festival on September 6, 1896, because normal magneto-ignition production for slow-running stationary combustion engines had increased very gradually from 42 to 1,000 magneto-igniters from 1887 onwards. This detonator type “6” was delivered to the Körting company in Körtingsdorf near Hanover. This low-voltage device was still a magneto with a pendulum armature, which reached around 100 revolutions per minute. Robert Bosch assumed completion from 1,000. Ignition device as an occasion to take 13 employees of the 16-strong workforce on a trip to Geradstetten .

There were other ignitions, such as the very highly dangerous glow tube ignition by Gottlieb Daimler and the high-voltage battery ignition by Jean Josef Etienne Lenoir , also known as “buzzer ignition”, which currently only allowed a few dozen kilometers of operating range. In the case of hand-started automobiles, of course, the engine moved only slowly, as did the magneto armature. The result was a relatively weak spark that was not always enough to ignite the fuel mixture .

The breakthrough with the magneto came about in 1896 through the development work of Arnold Zähringer, who had finally made possible over 1000 speeds per minute with the low-voltage magneto ignition that was common at the time . Instead of the pendulum wound armature, Zähringer placed a rotating metal sleeve between magnets in the double-T armature , which was provided with a wire winding and which became the Bosch logo in 1919 , through which the armature could remain in the rest position between the magnets (DRP 99399 ). Thus, higher revolutions for high-speed internal combustion engines could now be achieved by the snap-on igniter, so that installation in the automobile could begin. However, the weak point in Zähringer's design remained the complicated breakaway rod. In order to generate the ignition spark in the combustion chamber, this linkage was required and had to be redesigned for each engine because it was maintenance-intensive and prone to failure.

The Bosch apprentice Max Rall had to make the first attempt with a magneto in a vehicle in 1897 during a test drive. With a motor vehicle, the Beeston -Voiturette (a British copy of the De Dion-Bouton three-wheeler, but with glow tube ignition), which was delivered to Stuttgart by the English Bosch representative Frederic R. Simms , who also placed the order, the exact speed should be determined of the engine can be determined. The previous ignitions delivered a maximum of 200 sparks per minute and the small Beeston engine now reached 600 revolutions, whereby a corresponding number of 300 ignition sparks was required.

This test drive, instructed by Arnold Zähringer, ended with an accident that went smoothly. Max Rall, who later became director of Robert Bosch GmbH , had made the first successful attempt with a built-in Bosch magneto in a motor vehicle and marked a milestone in Bosch and automotive history. The so-called invention by Zähringer, which he had actually only developed further, was patented for Bosch and was successfully marketed as the “Bosch breakaway ignition” from 1898 onwards. In 1897 the workshop was already too small again and from 1897 (until 1901) it moved to Kanzleistraße 22 and the company was now called "Elektrotechnische Fabrik".

From autumn 1898, Gottlieb Daimler offered the Phönix trucks he had manufactured to Daimler-Motoren-Gesellschaft (DMG) with a new Bosch low-voltage magneto ignition. As early as July 1898, Daimler's commercial vehicle was tested for five days in the Austrian Tyrolean Alps .

In 1900 Robert Bosch was able to acquire his own property with a house in Military Street, which was adjacent to Hoppenlaustraße. It became his first own factory. In 1901 Robert Bosch relocated his company to his first own factory building, which he had rebuilt on Hoppenlaustraße in Stuttgart. In that year, the further developments of the low-voltage magneto ignition with the revolving armature were made under the direction of Zähringer and in 1901 the revolving sleeve was completed. By 1900, Zähringer and Robert Bosch had already developed 12 different magneto models, which generated sales of around 295,000 Reichsmarks .

In the summer of 1901, Robert Bosch commissioned Gottlob Honold , who had just become an engineer with him , to design a magneto ignition without a breakaway rod, and after a few months Honold presented his improved magneto as a high-voltage magneto, also known as "arc ignition". In 1902, the magnetic-high voltage ignition with a grade was the spark plug , which now mechanical parts especially in the combustion chamber reduced and even higher speeds enabled the engines presented. On September 24th, Bosch delivered the first high-voltage magneto to Daimler-Motoren-Gesellschaft.

As operations manager, Zähringer continued to work on the requirements of the engine designers and was thus able to bring about further developments until 1913, which u. a. to the Bosch headlights and the alternator for supplying the starter battery as power storage, the regulator switch for even battery charging, the oiler as a motor lubricating pump , the taillights , position lights and the fog lamps . When, in 1914, an electric starter engine for starting motor vehicle engines was finally ready at Bosch , Zähringer had to leave the company that same spring for health reasons. He officially left the company "Elektrotechnische Fabrik Robert Bosch", which now has over 4,000 employees, on December 31st. After his recovery, Zähringer moved to the Grossag company in Schwäbisch Hall , where he acquired 49% of the company's shares.

Arnold Zähringer started with the first usable “magneto for automobiles” as a key product that Bosch became an international group as an automotive supplier.

Web links

Individual evidence

  1. ↑ Intermezzo , accessed on September 13, 2012
personal data
SURNAME Zähringer, Arnold
BRIEF DESCRIPTION German inventor of the magneto for high-speed engines
DATE OF BIRTH May 9, 1869
PLACE OF BIRTH Furtwangen
DATE OF DEATH January 1, 1942
Place of death Stuttgart