Automatic Transmissions

  • John Jewkes
  • David Sawers
  • Richard Stillerman


The story of the attempts to replace the manually operated gear-box and clutch of the motor-car by automatic transmissions giving smoother and simpler driving without an unacceptable loss of efficiency is a long and intricate one and only the bare outlines can be given here. The two main types of automatic transmission now used involve:
  1. (a)

    the combination of a hydraulic coupling with an automatically controlled epi- cyclic gear-box. This was the first fully automatic transmission to be introduced commercially, as the Hydra-Matic gear, by the General Motors Corporation of the United States;

  2. (b)

    the combination of a hydraulic converter-coupling (i.e. a torque converter in which the reactor is mounted on a free wheel, so that the features of a torque converter and a hydraulic coupling are combined) also with an automatically controlled epicyclic gear-box.



Speed Ratio Automatic Transmission Torque Converter Consult Engineer Individual Inventor 
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  1. 1.
    Föttinger, H., contribution to discussion on paper, ‘Recent Developments in Hydraulic Couplings’, Inst. Mech. Eng. Proc., 1935, pp. 158–61.Google Scholar
  2. 2.
    Heidt, P. M., Torque Converters, 1942.Google Scholar
  3. 3.
    Shorter, L. J., ‘Transmission Gear Developments’, Inst. Automobile Eng. Proc., 1937– 1938, P. 337.Google Scholar
  4. 4.
    M’Ewen, E., ‘Recent Developments in Automobile Transmissions’, Inst. Mech. Eng. (Automobile Division) Proc., 1947–48, p. 97.Google Scholar
  5. 5.
    Letter from C. A. Chayne, Vice-President, General Motors, Jan. 25, 1956.Google Scholar
  6. Letter from A. W. Hallpike, May 30, 1956.Google Scholar
  7. 7.
    Letters from J. N. Fieldhouse, Vickers-Armstrongs Ltd., June 13 and 14, 1956.Google Scholar
  8. 8.
    Letter from E. W. Spannhake, June 26, 1956.Google Scholar
  9. 9.
    Chayne, C. A., ‘Automatic Transmissions in America’, Inst. Mech. Eng. (Automobile Division) Proceedings, 1952–53, Pt. 1.Google Scholar

Copyright information

© John Jewkes, David Sawers and Richard Stillerman 1969

Authors and Affiliations

  • John Jewkes
  • David Sawers
  • Richard Stillerman

There are no affiliations available

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