Intermittent motion
The mechanisms, either simple or complex, to transform motion from rotational into intermittent are based on the same principle: the crown gears, or pinion gears have the toothing placed in the middle of the surface; in this way the contact between the gears is intermittent with a cyclical rotation clockwise and vice versa. The element conducted can be a rack, a toothed gear or a rope.
Worm gear sttering
On the graphic-mechanic level, Leonardo’s project for a vehicle steering is modern. It is composed of a worm gear that interlocks a toothed sector; its rotation, right or left, affects movable rods and joints. The analogy with the system present in the steering of the Fiat car in the 60’s is amazing.
Winch hammer
The function of this “mechanism” is based on the fact that in handling the winch the rope wrapped around it makes the internal wheels (that are movable) shift toward the external pulleys (that are fixed).
This movement makes the shafts connected to the movable wheels spread out. Leonardo does not explain the exact use of this “mechanism”: probably he thinks of its application in the textile industry or a model that imitates a structure seen at courtly feasts where Leonardo was invited and appreciated.
