Page 9 - ATZ WORLDWIDE

Brakes

the Frankfurt Motor Show in 1925 in the Horch 10/45 and the
Mercedes 16/50 models.
At the time, some engineers were not convinced of the need
for servo brakes. E. A. wrote in ATZ 8/1926: “I maintain that
servo brakes of any sort are an unnecessarily complex and
costly solution in normal production models.” By contrast
W.‹Loewenthal explained in ATZ 26/1926: “The intensity of the
braking process should be controlled by feel in the form of the
resistance of the return springs (pedals, Ed.) and not by the
reaction of the braking force.”
The question of whether the same braking force needed to
be applied to all the wheels or whether it was sufficient to brake
only two wheels caused controversy for some time within the
industry. In ATZ 17/1926 Th. Kch. attempted to take an objec- 1927 The first servo brake for commercial vehicles (© Bosch)
tive approach to the situation at the time. His tables for calcu-
lating braking forces and distances became an important tool
in vehicle design over the decades that followed. J. Geiger
highlighted the issue of the increasing power of vehicles, which
placed greater demands on the braking systems. In ATZ 2/1937
he discussed the problem of the build-up of heat in clutches
and brakes.
The 1950s saw a major technological leap forward. H. Sitter-
ding reported on the first appearance of the disc brake in an
article about the 38 Frankfurt Motor Show in ATZ 11/1957.
th
Ernst Meier had already discussed experiences of open disc
brakes in ATZ 9/1957 and took a skeptical approach to the new
technology, which was first used in the BMW 503 model (in 1957 The BMW 503 was the first German car to come as standard with
1957). Porsche was also in the process of developing disc disc brakes (© BMW)
brakes. “The disc brake system designed by Porsche, which is
being manufactured by Teves, is used both in the Carrera-2 and
in the racing car, with the only difference being that the brake
caliper in the racing car is made from aluminum alloy rather
than steel,” explained E. Seifert in ATZ 2/1963.
Disc brakes soon became standard equipment. In ATZ 5/1963
H. Sitterding wrote: “Disc brakes are already becoming wide-
spread, even in small cars that travel at normal speeds.”
Against this background, the author calls for the single circuit
brake systems which were the norm in Europe at the time to
be replaced by dual circuit brakes “by all manufacturers in the
interests of road safety.”
Other innovations were being introduced at the same time.
In the 1960s, long before the invention of ABS, an anti-lock
device was designed to prevent overbraking of the rear wheels,
as reported by F. Beuchle in ATZ 8/1963. The ABS system that
Bosch launched in 1978 was adopted just as quickly as disc 2008 Carbon brake discs on a test rig (© Audi)
brakes had been. In ATZ 2/1987 the TÜV, the German testing
and product certification organization, confirmed after com-
prehensive tests that the new system had measurable advan-
tages. “During a total of 769 road trials, vehicles with normal
brakes got into difficult situations two-and-a-half times as often
as vehicles with ABS.”
Six years later in ATZ 11/1998 Wolf-Dieter Jonner and others
reported on the fifth generation of ABS and traction control.
The ESP system described for the first time in ATZ 11/1994 and
introduced in 1995 used the brakes for its interventions, as do
many current and future assistance systems. In the era of
autonomous driving, regardless of whether the driver or the
car is in control, accurate braking is still one of the essential
skills. 2017 The MK C1 brake system was upgraded to meet the additional
Stefan Schlott requirements of highly automated driving (© Continental)
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