This new mechanical transmission relies on a completely new method, which enables manufacturing very efficient automatic stepped gearboxes.

The main innovation is that the transmission ratio varies automatically
according to the transmitted torque.

The goal is to generate very significant energy savings by always running engines under the conditions in which they perform best.

Unlike the variable ratio transmissions of the prior art, this new automatic gearbox produces neither acyclism nor vibration, and provides at all times the best possible performance.

There is no friction, no slippage, and the movement is transmitted only by only a pair of classical toothed gears.

We have already built this first model which is working satisfactorily, and we have discloses a video on LinkedIn which has been viewed more than 7,000 times the first week after it was posted. It proposes three possible transmission ratios: three primary gears are driven by the motor, and three secondary gears are driving the output shaft.

Alltogether there are three pairs of gears that are always connecte although one only is transferring the torque.

French version

How it works

This first presentation does not explain everything... and the complete information is transferred only to industrial groups having signed an appropriate NDA.

However, we can allready disclose two first details:

  • Each primary gear is transferring the movement to the relevant secondary one only if the torque to which it is subjected is comprised between two predetermined values. This may happen because there is a very specific and very innovative torque limiter between the primary shaft and the primary gears.
  • The output shaft rotates at the speed of the secondary gear which rotates the fastest, because the secondary gears are each connected to it by a free wheel.

As a result, the transmission ratio is allways the best possible one, which will provide energy savings to the very many possible applications.

The design is extremely simple and inexpensive. Adding an gear ratio requires only two gears, our very specific torque limiter and a freewheel.

Below are all the components of this first working model of a fully automatic gearbox, although some of them are voluntarily not made visible at this stage.

As one can see, it is quite easy to have a very large number of gear ratios which pass by themselves as required, without any electronics.

More features...

One can determine in real time the rule of shifting according to the torque. When such a transmission is implemented for a car for example, one can thus pass progressively or instantly from a "sport" mode to an "economic" mode on a simple command.

This command also allows to change gear manually if desired.

An automatic clutch may be added to the device, just as an additional gear ratio, and our method will also make it work without friction or slippage

An reverse gear may also be added to the device, also just as an additional gear ratio.

It is possible to combine these automatic transmissions in series. The output shaft of the first gearbox is in this case the input shaft of the second, and the input and output shafts of the assembly can be aligned. Another advantage is that the number of possible gear ratios is then the product of the number of gear ratios of each of the two combined transmissions.

A few examples...

The main target markets are cars and trucks, bicycles and all types of vehicles, liners and all kinds of boats, robots, winches, power generators, etc.

One very important application is downsizing engines, especially the electric ones. At the present time, their power is chosen so that they support the maximum torque to which they risk being subjected. It means they are too powerful in normal conditions. With this new transmission, a smaller engine, which is at the same time cheaper and lighter, which uses less energy and needs less space, will become sufficient. This is important for all industries, from home appliance or toys to very powerful machines.

New bikes will no more have a dirty chain or complicated mechanisms, as our new gearbox will automatically adapt the gear ratio to the road conditions. The cyclist will no more change speed manually but only select his preferred mode at any value comprised between a sport or relax cycling mode.

We shall also renew the conception of all manual or electric winches of sailing boats. At the present time, best winches are 2-speed. One has to choose manually the one which is best adapted depending on the wind conditions and the status of the sail. With this new transmission, it becomes completely different: the sail will be hauled in quickly as long as it does not take the wind, but the transmission ratio of the winch will be automatically demultiplied when time comes to harden the sheet. It is exactly the same that will happen with a fishing reel, quickening the time necessary to rewind the line, but facilitating the work when there is a big fish to bring aboard.

If you want to know more

The first patent applications have been filed, and will be extended in many countries.

We have signed some agreements with industrial groups, some of which are already enjoying exclusivities.

Download the official publication which exists also in French.

Do not hesitate to contact me by mail at or by LinkedIn.

Franck Guigan
February 14. 2020