Figure 122.—Post Pump Jack. This arrangement is used in factories when floor space is valuable. The wide-face driving-pulley is shown to the left.
Figure 123.—Three Jacks for Different Purposes. At the left is a reverse motion jack having the same speed turning either right or left. The little jack in the center is for light work at high belt speed. To the right is a powerful jack intended for slow speeds such as hoisting or elevating grain.
Figure 124.—Speed Jack, for reducing speed between engine and tumbling rod or to increase speed between tumbling rod and the driven machine.