London : Longman, Rees, Orme, Brown, Green, and Longman · leaf 234
at its upper end, consists of a fork (z z), with a strap-link at eachextremity, which takes the crank-pin (o^) at each side of the disk,or solid wheel {a), with teeth on its edge, and wrought by a pinionand winch, as before described. At each side of this disk is castto it a roller (o o), or drum,… … L._x-J 1 I L J L 10 ^% and relieves the moving power of the weight of the valve andstalk; but, as soon as the valve has been raised a little, and, con- 222 Improved Methods of constructmg Valves or Sluices,
Architecture
Internet Archive · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer03inte-133-72.webp)
