Watt patented the application of the sun and planet gear to steam in 1781 and a steam locomotive in 1784, both of which have strong claims to have been invented by Murdoch. The patent was never contested by Murdoch, however, and Boulton and Watt's firm continued to use the sun and planet gear in their rotative engines, even long after the patent for the crank expired in 1794. Murdoch was made a partner of the firm in 1810, where he remained until his retirement 20 years later at the age of 76.
Watt patented the application of the sun and planet gear to s,team in 1781 and a steam locomotive in 1784, both of which have strong claims to have been invented by Murdoch. The patent was never contested by Murdoch, however, and Boulton and Watt's firm continued to use the sun and planet gear in their rotative engines, even long after the patent for the crank expired in 1:794. Murdoch was made a partner of the firm in 1810, where he remained until his retirement 20 years later at the age of 76.