Fig. 57.
A very handy arrangement for moving pulleys is a bolt and nut. Fig. 57 shows the bolt and nut with a piece of pipe attached. A piece of pipe can be cut to suit the distance between the nut and hub of one pulley while the bolt head is against the other hub. The nut is screwed back upon the bolt as far as possible. A washer is then placed against the nut, and a piece of pipe cut to suit. Of course, the pipe must be large enough in diameter to fit over the bolt. If we screw back upon the nut, a powerful strain can be brought to bear between the hubs and in all probability the pulley will move.
Fig. 58.
In taking down solid pulleys from main or counter shafting it sometimes happens that a hanger must be removed to permit the pulley to be taken off. A first-rate plan is to make a couple of long bolts hooked at the end as shown in Fig 58; pass the hook around the shaft and the threaded end through a hole in the stringer. By screwing up the nut as shown, the shaft and remaining pulleys can be kept in position, obviating the use of tackle, not to mention the labor required to hoist back the shaft into position. The application of this contrivance is especially valuable where heavy cone pulleys are required to be lowered or changed. It will be seen that if we employ a pipe thread we will be enabled to suit almost any condition of length that may arise between the shaft and stringer.
VII
PRACTICAL METHODS OF LOOSENING
PULLEYS
When a solid pulley is to be removed from a piece of shaft for any reason, it is not good policy to use sledge hammers on the spokes or hub to do it. Cast iron in pulleys is too liable to break or crack under repeated blows.