[Fig. 75]. Clutches.—This is a piece of mechanism which is required in so many kinds of machinery, that we show several of the most approved types.
[Fig. 76]. Ball and Socket Joints.—The most practical form of ball and socket joints is simply a head in which is a bowl-shaped cavity the depth of one-half of the ball. A plate with a central opening small enough to hold in the ball, and[p. 74] still large enough at the neck to permit the arm carrying the ball to swing a limited distance, is secured by threads, or by bolts, to the head. The first figure shows this.
[Fig. 77] illustrates a simple manner of tightening the ball so as to hold the standard in any desired position.
[Fig. 78]. Tripping Devices.—These are usually in the form of hooks, so arranged that a slight pull on the tripping lever will cause the suspended articles to drop.
[Fig. 79]. Anchor Bolt.—These are used in brick or cement walls. The bolt itself screws into a sleeve which is split, and draws a wedge nut up to the split end of the sleeve. As a result the split sleeve opens or spreads out and binds against the wall sufficiently to prevent the bolt from being withdrawn.
[Fig. 80]. Lazy Tongs.—One of the simplest and most effective instruments for carrying ice, boxes or heavy objects, which are bulky or inconvenient to carry. It grasps the article firmly, and the heavier the weight the tighter is its grasp.
[Fig. 81]. Disc Shears.—This is a useful tool either for cutting tin or paper, pasteboard and the like. It will cut by the act of drawing the material through it, but if power is applied to one or to both of the shafts the work is much facilitated,[p. 75] particularly in thick or hard material.