| 摘要 |
<p>A number of motor-driven rollers at intervals haul the strip along and a first variable potentiometer is connected to a part of each motor and to a power source. All first potentiometers are coupled together for simultaneous adjustment, while a second variable potentiometer is connected to another part of each motor and to a power source. A strip tension detector reacts to variations in tension and is coupled to each of the second potentiometers, varying the speed of an individual motor and its respective roller independent of the others. Each detector can have a feeler bar capable of angular movement and situated where the strip is guided or diverted. Thus when tension alters it moves in the direction of the strip and actuates the second potentiometer via a coupling.</p> |
