| 摘要 |
PURPOSE:To prevent cleaning defects by reducing the force, with which two levers constrict a turning center shaft, very much by the tension of a spring which gives a pressing force to a cleaning blade. CONSTITUTION:The length of a detaining arm 21 is so set that a rise part 12b of the first lever 12 and an arm 13a of the second lever 13 are not brought into contact with each other. A contact B2 between the second lever 13 and the detaining arm 21 is distant from a shaft 11 but is near an attaching point D of a spring 14. A connection center point B1 between the first lever 12 and the detaining arm 21 is distant from the shaft 11 and is near an attaching point C of the spring 14. Points B1 and B2 are fulcrums when the first and the second levers 12 and 13 constrict the turning center shaft 11 by the tension of the spring 14. Since a constricting force F3=b/aF1 and b<<a are true, the force F3 is very weak. Consequently, the first and the second lever 12 and 13 do not bite the shaft 11 and are turned smoothly. Thus, cleaning defects due to impossibility of withdrawing of a solenoid 17 are prevented. |
