Fig. 814.
[Fig. 814] shows a follower rest in position on the cross slide of a lathe.
Chucks and Chucking.
There is a large class of small work that could be held between the lathe centres, but that can be more conveniently held in chucks. Chucks are devices for holding work to the live spindle, and may be divided into classes as follows:
1st. Those in which the work is secured by a simple set-screw.
2nd. Drill chucks, which are applied mainly to drive drills, but which may also be used to drive very small work to be operated upon by cutting tools, the mechanism causing the jaws to move simultaneously to grip or release the work.
3rd. Independent chucks, in which the jaws are operated separately.
4th. Universal chucks, which are larger than drill chucks, and in which the jaws operate simultaneously.
5th. Combination chucks, in which the jaws may be operated either separately or simultaneously as may be required.