Fig. 1526.
Fig. 1527.
In [Fig. 1526] it is shown without, and in [Fig. 1527] with a swivel motion. The arrangement of the jaws upon the base in [Fig. 1526] is similar to that of the chuck shown in [Fig. 1522], but instead of there being a key to secure the piece f to the base, there is provided on each side of the base a row of ratchet teeth, and there is within f a circular piece g (in [Fig. 1528]) which is serrated to engage the ratchet teeth. This piece may be lifted clear of the ratchet teeth by means of the pin at h, and then the piece f may be moved freely by hand backwards or forwards upon the base and swung at any required angle, as in [Fig. 1528], or set parallel as in [Fig. 1527]; f becoming locked, so far as its backward motion is concerned, so soon as h is released and g engages with the ratchet teeth on the base. But f may be pushed forward toward the fixed jaw without lifting h, hence the adjustment of the sliding jaw to the work may be made instantaneously without requiring any moving or setting of locking keys or other devices.
Fig. 1528.
It is obvious that it is the capability of g to rotate in their sockets that enables f to be set at an angle and still have the teeth of g engage properly with those on the base plate.