Cycle Clutch Trigger
Original Publication Date: 1979-Jan-01
Included in the Prior Art Database: 2005-Feb-19
Experimental results have shown that impact force variations in certain typewriters are in some measure caused by fluctuations in print shaft velocity (RPM). A major cause of this RPM variation is the 120 Hz torque variation inherent in AC motors (caused by 60 Hz AC line voltage). Attempts to mechanically remove this variation generally prove unsuitable to production machines. With the advent of electronic control of typewriter mechanics it becomes possible to synchronize machine timing with this torque variation and thereby reduce printshaft input variations at any particular instant in the print cycle. In particular, by synchronizing cycle clutch pick timing with AC line frequency, impact force variations for repeats of the same character on a typewriter are reduced 30-60 percent.