[1248]. Round grooved chain pulley.
[1249]. Double grooved chain pulley; prevents the chain twisting.
[1250]. Pitched chain snug pulley or sprocket pulley. The pitch of snugs should be slightly longer than the chain, to allow for wear and stretching of the chain.
[1251]. Chain sprocket wheel, for long link chain at slow speeds.
[1252]. Sprocket wheel, for long flat link pitched chains.
[1253] & [1254]. Sections of rim showing single and double links.
[1255]. Sprocket wheel, for Ewart’s patent pitched chains. See Chains &c., [Section 11].