Using 1 motor for 2 different functions

[marinmersenne]

I believe this is what is meant by a 4-bar transmission as mentioned by Xenon27:

Differential transmission - power takeoff from the drivetrain motors

[Vex differential transmission animation] In mechanical engineering Differential is primarily associated with a specific drivetrain component connecting axles of the powered left and right side wheels. But formally it is defined as: A differential is a gear train with three shafts that has the property that the rotational speed of one shaft is the average of the speeds of the others, or a fixed multiple of that average. For whatever reason, in vex context, any power sharing s…

We personally use one of these 4-bar transmissions on our robot and it works great but it requires two motors not one.

An alternative to the double ratchet would be this:

The below image only has one of the two output gears connected.

(Edit to clarify):
The design relies on the friction of the ‘drive arm’ with the motor axle to swing the arm into engagement with one of the two output gears depending on the direction the motor is turning.