Corkscrew mechanism

Leonardo invented this "corkscrew" mechanism : He recommended the use of this feature to prevent the wheel's inverse rotation.

By pressing on multiple wheel cogs the force is distributed.

Credit : HK Sciences Museum.

Autolock device

The use of this device is essential above all in machines designed for lifting great weights. It consists of a wheel with teeth set at an acute angle and of a flat-tipped hook that engage the teeth one at a time so that the wheel cannot turn backwards.

Credit : HK Sciences Museum.

Ball bearings

Leonardo attempted to find ingenious techniques for reducing friction.

Here eight concave-sided spindles rotating on their own axes prevent lateral movements by the balls, which can however rotate freely.

The ball-and-spindle system reduces friction, allowing the top platform to turn easily even when carrying a heavy load.

Credit : HK Sciences Museum.

Three ball bearings

The application of this principle is still widely used today. A series of balls is placed between two moving surfaces that would otherwise rub together creating a great deal of friction, and thus, greater damage to the parts.

In this instance Leonardo improved upon this principle by devising a ring-shaped track along which the balls could move without coming into contact with each other.

Credit : HK Sciences Museum.

Car powered by springs

This is one of the most famous Leonardo's inventions. It is a self moving car propelled by a complicated mechanism powered by leaf springs (balestre). The car system suggests that an operator would have to hand-load the leaf springs.

The stored energy is transmitted to the diving wheels by means of a complex set of gears.

He also incorporated a small rubber-wheel to steer the car.

Credit : HK Sciences Museum.

Cam hammer

Leonardo often made use of cams, the projection on a rotating part which generates reciprocating motion or regular percussive motion from a rotary.

Because of the cam, the action is regular.

Credit : HK Sciences Museum.

Tongs

The greater the weight held by this lifting tong, the better and stronger it will be supported.

Credit : HK Sciences Museum.

Fly wheel

After studying carefully the physical principles involved Leonardo came up with this demonstration machine.

The device is able to build momentum in order to overcome inertia and thus, reduce effort.

Credit : HK Sciences Museum.

Chains

Leonardo studied many different types of flexible chains, used for transmission of continuous motion. However, the square shape of the teeth and the weights hanging on them lead us to believe that they were meant to transmit discontinuous motion and in particular were conceived for release mechanisms like clocks.

Chains are also used in one of the most famous machines : the bicycle.

Credit : HK Sciences Museum.

Jack

This machine is easy to understand for anyone who has tried to change the tyre.

It is made from a crank, reduction gear and rod with teeth that can move up and down.

Credit : HK Sciences Museum.

Study of perpetual motion

Leonardo using drawings and comments proved the impossibility of perpetual motion, the subject of many discussions in his time.

The instrument drawn here is built from sticks with weights attached to the ends.

Credit : HK Sciences Museum.

Gear with a circular mechanism

This system for producing motion appears often in Leonardo's machines.

In order to produce rotary movement, he frequently used the cogwheel. But Leonardo also tells us that the cogs wear down moving big loads, thus suggested using 'corkscrew' mechanism instead.

Credit : HK Sciences Museum.

Flapping wing experiment

Leonardo thought that if it was possible to lower the long lever rapidly enough, the wing would have lifted the plank mounted on it (about the weight of a man). Leonardo calculated the measurement of the wings span on the basis of his observations of birds.

The correct measurement of the wings must have been 12 meters long by 12 meters wide.

Credit : HK Sciences Museum.

Study of forces and rotational motion

A bovine pulling 9 ropes attached to a pole in front of 4 wheels representing the wheels of a cart. ... "Any object struck or pulled at a distance from suo nascimento / its birthplace (fulcrum) is more easily pulled to the ground".

The tree trunk shown will be pulled to the ground by a single bull if pulled by rope 9.

As a consequence, Leonardo explains that it is easier to pull (or rotate) the larger wheel if it is of equal weight to the smaller ones.

In this experiment, Leonardo demonstrates that the further the distance of the applied force to the fulcrum of an object (suo nascimento/ its birthplace), the more easily it is rotated.

Credit : HK Sciences Museum.

Study of the mechanical wing

Leonardo was not contented to put feathers on people's arms as in Greek Mythology; he was determined to create the mechanism to give man flight.

In a series of revolutionary drawings, such as the "Flapping Wing" and the "Mechanical Wing", he showed details of the first prototype of a fully mechanised flying machine. In this particular study of the wing, Leonardo mimicked the birds ; flapping structure with levers, pulleys and flexing of rods and ropes for tendons.

These studies would lead him to the discovery of a modern day invention - the Gilder.

Credit : HK Sciences Museum.

Flying machine

This is one of the most famous drawings by Leonardo da Vinci.

It is very precise and is accompanied by useful explanations.

The man lies stretched out on the platform and puts his feet in the stirrups, which raises the wing while the other lowers it.

Credit : HK Sciences Museum.

Study of a wing in one piece

After his studies on bird anatomy, Leonardo decided to apply the same laws to his flying machines. He directed his interest towards an united wing which, like that of a bat, was supposed to have a single cloth stretched over a structure of wood and cane.

Credit : HK Sciences Museum.

Air Screw

This is certainly one of Leonardo's most famous designs since it one recognizes an ancestor of the helicopter.

This craft made of reeds, linen, and iron thread would have been operated by four men who, by rotating a shaft, could lift themselves off the ground.

It is clear that the mechanism so conceived could never have taken off, but the idea remains that with the force of an adequate motor, the machine would actually have spun itself into the air and off the earth.

Credit : HK Sciences Museum.

Anemometer

Leonardo showed his great talent with this machine.

He created not only the flying machines, but also the instrument to control flight.

One of these instruments is the anemometer which measures the power of the wind. In its simplicity it is just a graduated stick with a hanging blade which is moved by the wind.

Credit : HK Sciences Museum.

Inclinometer

This instrument serves to regulate flight.

It consists of a pendulum inserted in a glass bell so as to protect it from the influence of wind.

The position of the ball of the pendulum indicates the position of the craft in relation to the horizontal.

Credit : HK Sciences Museum.