Idler
1, An idle wheel. 2, A wheel for transmitting motion from one wheel to another, either by contact or by means of belts, as the wheel on a countershaft, or overhead fixture. 3, An intermediate wheel used for reversing motion. Figs. 172 and 173 illustrate two forms of idlers, sometimes called overhead fixtures. The supports for the idlers are adjustable in all directions. They are especially valuable for use on slide rest tools, such as polisher, milling attachments, etc., to give a vertical direction to the belts. The rods are about 20 inches long and the pattern shown in Fig. 172 has a ball and socket joint where it is screwed to the bench. The radial arms which hold the pulleys may be adjusted to any position on the rod by means of a thumb screw, and the pulleys have a lateral play of 3/4 of an inch to aid in maintaining greater freedom of the belt during the travel of the tool on the slide rest. The idlers shown were designed by A. W. Johanson, and have hard rubber pulleys 1 3/4 inches in diameter, having brass bushings. The style shown in Fig. 173 is intended to be clamped on the swiveled bearing of the counter shafts which are supported on standards.