This illustration from WattΓÇÖs rotary engine patent shows one method Watt proposed using for converting parallel motion into rotary motion. This method involved using a pulley attached to one end of the connecting beam of the engine to pull on a wheel. The top part of this figure shows a top view of the wheel that was being turned by the engine. The bottom part of the figure shows a side view. The pulley is the line connected to the right side.
STEAM ENGINE PATENT (1785)
This patent illustration, from WattΓÇÖs 1785 patent, shows a new type of piston called an oscillating piston. This device was actually invented by William Murdock, who was WattΓÇÖs chief engineer.
DUPLICATING PRESS PATENT (1780)
Watt invented the copying press because he grew tired of copying his correspondence by hand. His patent includes specifications for two different types of copying presses-a roller press and a screw-down press. The presses were used to duplicate both letters and drawings.
ROTARY ENGINE PATENT (1781)
This illustration from WattΓÇÖs rotary engine patent shows one method Watt considered using for creating rotary motion. The diagram shows how the connecting rod is attached to both the piston and a rotating device, such as a wheel. In this picture, the rotating device is not included, but would be attached to the line on the left.
ROTARY ENGINE PATENT (1781)
WattΓÇÖs rotary engine patent included five different gear systems that would convert up-and-down motion into circular motion. This patent illustration shows one of these methods.
ROTARY ENGINE PATENT (1781)
This patent illustration from WattΓÇÖs rotary engine patent shows a second gear system for converting parallel motion into rotary motion. This gear system was known as an eccentric gear because the gears did not move in an circle around a center point.
ROTARY ENGINE PATENT (1781)
This diagram from WattΓÇÖs rotary engine patent shows a variation on the sun-and-planet gear system. In this set-up, the smaller gear moves inside the larger gear.
ROTARY ENGINE PATENT (1781)
This diagram from the rotary engine patent shows the sun-and-planet gear system that was eventually used in WattΓÇÖs rotary engines.
STEAM ENGINE PATENT (1784)
WattΓÇÖs 1784 steam engine patent included methods for using steam power to move mills. This diagram shows a cross section of a iron-slitting mill. The cross beam of the engine is connected to the beam along the top at the point labeled A.
STEAM ENGINE PATENT (1784)
WattΓÇÖs 1784 steam engine patent included methods for using steam power to move mills. This diagram shows how the connecting rod of the engine is attached to the gear wheels that are used to turn the mill.
DOUBLE-ACTING ENGINE PATENT (1782)
This patent diagram shows one version of WattΓÇÖs double-acting steam engine. The tooth-like sections along the top of the piston rod and the edge of the connecting beam allowed the piston to move up and down inside the cylinder.