| 摘要 |
PURPOSE:To accurately move forth and back each developing device only by the rotation of an interlocking cam by engaging an interlocking element which couples with the interlocking mechanism of a developing device with the profile groove of the interlocking cam. CONSTITUTION:The interlocking cam 77 consists integrally of a cam body 83 formed by forming a projection 82 at part of the peripheral surface of a disk and guide walls 85 which are arranged along the peripheral surface of the cam body 83 and has the profile groove 84 between the cam body and guide wall. Rotary rollers 87 and 88 are provided as interlocking elements to one-end sides of interlocking arms 75 and 76 and those rotary rollers 87 and 88 are fitted in a free rolling state at constant intervals from the profile groove 84. When the 2nd developing device 7 is selected by an operator, a motor 79 is started to rotate the interlocking cam 77 and as the projection leaves the cam, the rotary roller 87 is drawn forcibly along the profile groove 84 to rotate the interlocking arm 75 counterclockwise, so that the 1st developing device 6 moves back away from a photosensitive drum 4 through said operation. |
