The jaws of the wood-worker’s vice are made then as in [Fig. 2083], and reach higher above the screw than the vices used for iron work, because the work is often of considerable depth, and being light will not lie still of its own weight, as is the case with iron.
Fig. 2084.
An example of the ordinary vice of the machine shop is shown in [Fig. 2084], which represents partly in section a patent swivel vice. a is the jaw in one piece with the body of the vice, and b is the movable jaw, being the one nearest to the operator. The movable jaw is allowed to slide freely through the fixed one (being pushed or pulled by hand), or is drawn upon and grips the work by operating the handle or lever h. The means of accomplishing this result are as follows: As shown in the cut, b is free to be moved in or out, but if h be pulled away from the vice, the shoulder c, meeting the shoulder n, will move the toggle g, and this, through the medium of g′, moves the tooth bar t, so as to engage with the teeth on the side of the movable jaw bar shown at t. As soon as the teeth t meet the teeth t the two travel together, and the jaw b closes on and grips the work. But as the motion is small in amount, the jaw b should be placed so to nearly or quite touch the work before h is operated. To unloose the work, the handle h is operated in an opposite direction, and the hook m meets m and pulls t to the position shown. The spring s operates upon a hook at u, to engage the teeth t, with the rack t, as soon as the handle h is moved in the tightening direction. The vice grips with great force, because during the tightening the toggle, g is nearly straight, and its movement less than would be the case with a screw-vice having the ordinary pitch of thread and under an equal amount of handle movement.
Fig. 2085.
In this vice the fixed jaw is made to fasten permanently to the work bench, but in others having a similar tightening mechanism the fixed jaw is so attached to the bench as to allow of being swivelled. The method of accomplishing this is shown in [Fig. 2085], in which s is the foot of the vice bored conical to receive a cone on the casting r, which is fastened to the bench b. w is a washer and h the double arm nut. Loosening this nut permits of the vice being rotated upon r.
When handle h is operated to release the movable jaw it can be moved rapidly to open and receive the work, and to close upon the work, when by a second handle movement the work can be gripped, the operation being much quicker than when the movable jaw is traversed by a screw and nut.