DRIVEN MACHINES 111 



Pump Jacks and Speed Jacks. Farm pumps and 

 speed-reducing jacks are partners in farm pumping. 



Figure 124. Speed Jack, for reducing speed between engine and 

 tumbling rod or to increase speed between tumbling rod and the 

 driven machine. 



Figure 125. The Speed Jack on the left is used either to reduce 

 or increase tumbling rod speed and to reverse the motion. The 

 Speed Jack on the right transfers power either from belt to tumbling 

 rod or reverse. It transforms high belt speed to low tumbling rod 

 speed, or vice versa. 



Force-pumps should not run faster than forty strokes 

 per minute. Considerable power is required to move 

 the piston when the water is drawn from a deep well 



