If, for example, the surface of the chuck requires to be used in setting the work, the jaws will often be in the way of the tools or instruments employed to set the work. Again, there may be projections on the work which will require the body of the work to be held too far from the face of the chuck to enable its jaws to grip the work.
To meet the requirements of these classes of work chucking devices, which may be classified as follows, are employed:—
1st. Chucking by bolting work to the face plate or chuck plate with bolts and plates.
2nd. Chucking between dogs movable about the face chuck plate, and holding the work from that plate.
3rd. Chucking with the aid of the angle plate, or with the angle plate employed in conjunction with the chuck plate.
Fig. 860.
