DEVICE FOR SWITCHING DRIVING FORCE

摘要

PURPOSE:To keep an idler in its neutral posture until it is displaced from its neutral position into contact with a driving rotary member, by providing a member which is located in contact with the idler at its two diametrally symmetric points when the idler is located between both driven rotary members. CONSTITUTION:Two protrusion 18a on the tip of a friction rod 18 are brought into contact with an idler 17 by a kick spring 20. Although an idler base 15 can be swung right and left about a control pin 14, the idler base is kept in the neutral state because a rightward and a leftward equal forces are applied to the center shaft of the idler 17 by the two protrusions 18a of the friction rod 18. When the idler base 15 is moved toward a driving roller 1, the idler 17 is continuously pushed by the protrusions 18a of the friction rod 18 so that the idler on the idler base is kept in the neutral state until the idler is displaced into contact with the driving roller 1.