P. 9


            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.
            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)
            ATZ worldwide  09|2018                                                                            7
   4   5   6   7   8   9   10   11   12   13   14