| 摘要 |
<p>Automatic paper bail actuator for a printer having a rotating platen (1) or equivalent means for feeding a printing support consisting in an helicoidal spring (16) wound on the platen shaft and having two end arms (13,14), a first arm (13) being elongated to interfere with the bail and a first reference stop (15), the spring coil (16) being clamped on the shaft (2) by interference with the bail and opening the bail when the shaft (2) rotates in the direction opposite to the one providing normal forward feeding of a printing support, closing the bail when the shaft (2) rotates in the direction providing normal forward feeding until the first arm interferes with the first reference stop (15) and releases the spring coils; the second arm (14) interfering with a second reference stop (17) for a rotation of the shaft (2) in the direction opposite to the normal one and releasing the spring coils for a predetermined angular position of the spring and the first arm, hence for a predetermined open position of the bail.</p> |
