AUTOMATIC GEARS.

Auckland Star, Volume LXXI, Issue 215, 10 September 1940, Page 12

AUTOMATIC GEARS.

Motor Notes.

POSSIBLE SOLUTION. EFFECT UPON DRIVERS. A possible solution to the multiplicities that confront the engineer in trying to work out the problems involved in the much-sought automatic transmission for the modern car, is contained in a recent dispatch from Detroit. L'.S.A. It is suggested that some modification of the turbine drive. might furnish the logical development from flip fluid coupling which has been recently employed. , The bringing of an oil-cushioned, flexible drive into the line, would appear to provide an adjunct to the smooth linal device which it is hoped to achieve. Such a fluid coupling, however, as its name suggests, is only a coupling. It has no properties of lorijtie increase.. The next logical step, therefore, is a torque converter of the turbine type. Thiri is merely an extension and development of the fluid coii]>ling, havinu blades of a more highly developed form and a third member to take the fluid reaction. It has all the smoothness of ilie coupling and acts as a coupling, but. in addition, has properties of torque increase in that it is clutch, coupling and transmission all in itself. It re-quires no governors or controls, no effort nor special knowledge on the part of the driver. He merely steps on the throttle and drives. It makes no noise, and there, is nothing to adjust, wear out or replace. The whole scheme, however, seems so perfect, in the abstract, that one is led to reflect on the possible reactions of an experienced driver to such a eystem. After all, he may still wish to drive, and traffic conditions may cause him to do something that is not theoretically correct. If the automatic controls or brain of the transmission will not let him do this, he will not be satisfied with the results. Making the gear-shifting automatic is not enough. Most drivers will wish to retain at will almost, the same amount of control thev have always had. The promptness of the automatic change is particularly important. Having been used to certain motions in handshifting the gears, the psychological effect on the driver, if he has nothing to do but wait for the shift to occur, will be to make the time interval see.m longer than it actually is. Then, too, the driver should get what he expects. That is, the transmission should definitely go through the expected series and not sometimes startle the driver by doing something else, such as occasionally missing a speed. This is where the strictly automatic device is apt to be unsatisfactory. The driver must be able to control, to quite an extent, the moment at which the gear shift is made. He may, for acceleration purposes, wish to dwell longer in tbe geared speeds, or the situation may be such that he would like to get up into top speed quite promptly. He may also wish to remaiu in top or perhaps third at a comparatively slow speed for some indefinite distance. Such requirements arc most difficult to meet either by torque or speed controlled governors.