James Watt - Patents

Patents

Watt was the sole inventor listed on his six patents:

• Patent 913 A method of lessening the consumption of steam in steam engines-the separate condenser. The specification was accepted on 5 January 1769; enrolled on 29 April 1769, and extended to June 1800 by an act of Parliament in 1775.
• Patent 1,244 A new method of copying letters; The specification was accepted on 14 February 1780 and enrolled on 31 May 1780.
• Patent 1,306 New methods to produce a continued rotation motion – sun and planet. The specification was accepted on 25 October 1781 and enrolled on 23 February 1782.
• Patent 1,321 New improvements upon steam engines – expansive and double acting. The specification was accepted on 14 March 1782 and enrolled on 4 July 1782.
• Patent 1,432 New improvements upon steam engines – three bar motion and steam carriage. The specification was accepted on 28 April 1782 and enrolled on 25 August 1782.
• Patent 1,485 Newly improved methods of constructing furnaces. The specification was accepted on 14 June 1785 and enrolled on 9 July 1785.