In this vice the gripping surface of the jaws are always parallel one to the other, and attachments are employed to grip taper work as wedges.
Fig. 2086.
Fig. 2087.
In [Fig. 2086] is represented a patent adjustable jaw vice, which is also shown in [Fig. 2087] with the adjustable jaw removed and upside down. From the construction it is apparent that the groove g, being an arc of a circle of which c is the centre, the jaw is, as it were, pivoted horizontally, and can swing so as to let the plane of the jaw surfaces conform to the plane of the work; hence a wedge can be gripped all along the length enveloped by the jaws, and not at one corner or end only. When the pin a is inserted the jaw stands fixed parallel to the sliding jaw. The pin a engages in a ratchet in the base below it to secure the back vice jaw in position when it is set to any required angle.
A second convenience in this vice is that the whole vice can be swivelled upon the base that bolts to the bench, which is provided with a central hole and annular groove into which the base of the field jaw pivots; at b is a spring pin passing into holes in the bench plate, so that by lifting the pin b, the whole vice can be swung or rotated upon the base or bench plate, until the pin b falls into another hole in the base plate, which is provided with eight of these holes. The movable jaw is here operated by a screw and nut.