Springs, levers and toothed-wheel mechanisms
Studies of steel and lead springs driving levers that engage the teeth of a wheel
The sheet is filled with small studies of springs, levers, crossbow-like frames and gear-and-rack fittings, with notes that repeatedly test the material of the spring. Leonardo labels one part 'a spring' and another 'the steel spring', but concludes that in any case a lead spring is required. A lever is shown running along a member and engaging the teeth of a wheel, and at the lower left a windlass or bench mechanism appears. The Ambrosiana index files the sheet under bombards.
On this page
Lever engaging the teeth of a wheel
A note explains the lever that catches the teeth of the wheel, describing how the lever must run along one member and be supported upon another, with a labelled point 'a - - a'. The surrounding drawings show the toothed wheel and the spring-loaded lever fittings.
A spring — steel versus lead
Successive notes label the parts as 'a spring', 'the steel spring', and 'lead for the spring', weighing the material to use. Leonardo concludes on the lower margin that in any case there must be a lead spring.
Crossbow and spring-actuated firing frames
Among the mechanisms are drawn bow-and-frame devices and spring-driven fittings of the kind used in light artillery and crossbows; the Ambrosiana index records the sheet under bombards. These military mechanisms are not covered by the transcribed captions.