Odd Gearboxes

Hobbs, Ljungstrom and Constantinescu.

On my day-off, I decided to build the Spontan Transmission Gear (S.M. 60 of 1934).

This interesting mechanism was originally invented by the Swedish engineer Fredrik Ljungström for use in cars. It never became a commercial success, though, as is was introduced during the Great Depression, and due to the fact that contemporary transmission fluids couldn't stand up - probably to the "whipping" movement of the swing arms at double engine speed.

How the Spontan Transmission works and how to build it

Another interesting type of gearbox using a centrifugal mechanism is the Hobbs Inertia Gear (S.M. 59 of 1934).

How the Hobbs Inertia works and how to build it

The Constantinescu Torque Converter (CTC for short) featured in the Meccano Magazine of April, 1924, wasn't a commercial success, either. According to contemporary literature, the main feature of this and other types of "gear-less box" was to liberate the driver from the drudgery of gear-changing. Synchromesh or not, driving an automatic car isn't half the fun of revving and shifting - not to speak of practising the fine art of "toe-and-heel" !