1841-1850
It was in 1841 that F. E. Sickels invented the drop cut-off valve gear, and the Corliss valve gear was patented in 1849 and 1851. Nasmyth’s steam hammer was invented in 1842.
Hoe’s revolving printing press was invented in 1845. The next year Sloan patented the gimlet-pointed screw. In 1847 Savage invented the time lock, and in 1849 Hibbert patented the latch needle for knitting machines. American machine-made watches appeared in 1850. However, the most important invention of the decade was Howe’s sewing machine in 1845.