Print Band Height Control Servo
Original Publication Date: 1986-Jun-01
Included in the Prior Art Database: 2005-Mar-09
The servo control for maintaining a selected print band height can be made less sensitive to height variations by requiring a predetermined count accumulation before permitting servo response to an out-of-limit condition. Referring to Figs. 1 and 2, endless print band 1 is constantly driven on flat drive and crowned idler pulleys (not shown) and passes through transducer 2 that senses the height of the lower edge of the band. A reversible motor is connected to the idler pulley shaft to adjust the pulley height and, hence, the band. Transducer 2, which may be a magnetic sensor, provides an analog output signal to sensor circuit 3 that energizes line A or B, indicating that the band is either too high or too low, respectively.