[438]. Double toothed-cam and lever combination.
[439]. Double lever and link motion, with increasing pressure. The strains are self-contained, and this plan is very suitable where an increasing pressure is required.
[440]. Lever and toggle motion (see [Section 63]). Many variations are in use for stone breakers, &c. See [Section 13].
Knapping toggle motion. See [Nos. 269], [251].
Section 23.—CONVEYING MOTION TO MOVABLE PARTS OF MACHINERY.
Motion may be conveyed to such parts of a machine as require to be movable, or to distinct machinery which has no fixed location, by the following means:—
[441]. Is an endless rope or other round section belt, kept tight in any position in the plane of the driving pulley by a weighted pulley. In this plan the machine can be moved to any position in the plane of the driving pulley, the weighted pulley taking up the slack of the belt.
[442]. Flexible shaft for light driving. It admits of considerable flexure, and is useful for drilling and similar incidental driving purposes in difficult positions.
[443]. Radiating arm and belt. The movable machine can be driven at any point in circumference of the circle described by the arm head.