Rockwell Automation Motion Analyzer Software - Manual (Page 97)

Rockwell Automation Publication MOTION-UM004B-EN-P - October 2012 97
Sizing Your System Chapter 2
2.1.4.1. Press Roll Feed (constant time/constant angle)
This application is typically cutting strip material such as steel into pre-set lengths
by means of a press shear (heavy-duty knife). The material must be stationary
when the cut is made and the cut takes place over a fixed amount of time or a
fixed angle of the driving crank whose speed is varied to match the cut rate.
Strip material is unwound from a reel at constant surface speed and fed via
separately driven leveler rolls into one end of a looping pit (a free-hanging loop of
material providing storage). On the other side of the loop, a pair of feeder rolls
grips the material and moves it forward the required cut length and then stops.
After the cut is complete, the material is moved again. The average velocity of the
nip/feeder rolls must be equal to the constant velocity of the unwinder and
leveler rolls.
Figure 78 - Press Roll Feed - Constant Time
Figure 79 - Press Roll Feed - Constant Angle