Fig. 1622.
[Fig. 1622] represents a form of planer chuck used on the smaller sizes of planers, and commonly called planer centres. a is the base or frame bolted to the planer table at the lugs l; at b is a fixed head carrying what may be termed the live centre d, and c is a head similar to the tailstock of a lathe carrying a dead centre; f is an index plate having worm-teeth on its edge and being operated by the worm g. At s is a spring carrying at its end the pin for the index holes. To bring this pin opposite to the requisite circle of holes, the bolt holding s to a is eased back and s moved as required. On the live centre d is a clamp for securing the work or mandrel holding dog. Head c is split as shown, and is held to the surface of a by the bolt h, which is tapped into the metal on one side of the split.
It is obvious that polygons may be planed by placing the work between the centres and rotating it by means of g after each successive side of the polygon has been planed or shaped, the number of sides being determined by the amount of rotation of the index plate.
Fig. 1623.
[Fig. 1623] shows a useful chuck for holding cylindrical work, such as rolls. The base is split at e, so that by means of the bolt and nut d the V-block a may be gripped firmly; b and c are screws for adjusting the height of the V-block a. At f is the bolt for clamping the chuck to the planer table, and g is a cap to clamp the work w in the block a. It will be seen that this chuck can be set for taper as well as parallel work.