Large eccentrics cause great loss from friction, unless provided with friction rollers in the sheave; but are sometimes used to avoid an additional crank in shaft.
[186]. Eccentric motion for multiplying travel of eccentric by leverage.
[187]. Crank motion to turn an angle instead of bevil gear and shaft, the cranks being of the form of [Nos. 174] or [175].
[188]. Shifting or variable throw eccentric. The sheave is slotted to fit the shaft, and its throw is governed by a disc having a spiral slot and locking bolt.
[189]. Another form of shifting eccentric. The sliding block is arranged to lock in any part of the slot in the sheave.
[190]. Another form of shifting eccentric, in which the sheave is loose on an eccentric boss cast with the worm wheel, and is revolved by the worm, the bearings of which are fixed to the sheave.
See also [Nos. 606], [712], [720], [728], [729].
See also [Sections 40] and [79].