"1931 's greatest contribution to motorcar performance ! "
Interesting.
I have been reading about old cars since, well, learning to read ( about 40-some years), and I have never run across this gizmo or heard of the "Automatic Drive and Transmission Co."....
Taking a somewhat educated guess from the advertising blather and the photo, my hunch is that this was essentially a centrifugal clutch device to replace the stock clutch. What is most interesting is that the driver has a control to select between full -manual operation, or "auto-matic drive"....
The theory of operation probably involved putting the car in 2nd or high gear and leaving it there. I'll bet the clutch facings burned-out pretty quickly for those folks who tried to drive this rig in high-gear.
The Fluid Drive introduced by Chrysler Corporation in 1939 on Chrysler, De Soto and Dodge, utilitized the same operating theory, but used a fluid-coupling with a conventional disc clutch and three-speed manual transmission behind it. In 1941, they added a four-speed semi-automatic gear box. This option lasted through 1953. In 1954 Chrysler Corp. brought out their first modern, truly "automatic" transmission: the 2 Speed Powerflite. In 1956, they added the legendary three-speed Torqueflite.
I would like to clarify that Chrysler's "Fluid Drive" cars, in their various forms, did NOT employ a "torque converter"; they used a "fluid-coupling", which produced no torque-multiplication, and in actual performance, achieved a little less than a 1:1 connection between input and output. Some old timers will say that the MoPar Fluid Drive was based on "slippage"... they are correct to a degree... instead of the "slippage" of the drive coupling resulting in burned-out friction facings, in the Fluid coupling, it was simply converted to heat.
Having owned several "Fluid Drive" MoPars, I can say that while their get-away performance was fairly embarassing, they were excellent in snow, and usually better on cruising on the highway than their dry-clutch cousins, as Fluid Drive equipped cars usually had taller gears in the rear end.
Getting back to the centrifugal clutch idea, REO introduced a "Self-Shifter" transmission in 1933, that used planetary gearing and centrifugal weights for shifting... there was a clutch pedal for stopping and getting under-way, but no gearshift lever - instead, there was a gear selector mounted under the dash, looking much like the T-handle emergency brake release in early Falcons and Mustangs.
And, the first "automatic" transmissions offered by Olds and Buick in 1938 were completely mechanical - there was no fluid coupling...
The first "true" modern automatic transmission ( Liquid coupling, planetary gear sets and bands, able to up-shift under load, etc.) was the GM Hydramatic, introduced in 1939-40.
I have to believe that the "Self-Operating Clutch" described in the ad was not a success, otherwise I think more of us would have heard about it down through the years...
It would be neat to find one though...
