Examples of stalling of operation of imaging devices are described herein. In an example, the imaging device includes an input roller assembly to transport a medium in the imaging device and a line feed roller assembly disengagably coupled to the input roller assembly to selectively drive the input roller assembly. To stall the operation of the imaging device, a line feed shaft of the line feed roller assembly can be automatically disengaged from the input roller assembly to discontinue advance of the medium along a print path.

An image forming apparatus includes a reconveying unit including a reconveying roller; and a second transmission mechanism. The second transmission mechanism transmits a drive force to the reconveying roller and includes an input gear; an output gear; an intermediate gear including first and second gears; and first and second swinging gears. The first toothless part of the first gear and the second toothless part of the second gear are provided at such a position that, when the intermediate gear is rotated by a drive force transmitted from the input gear through the second swinging gear while the second swinging gear meshes with the second toothed part of the second gear and the output gear meshes with the first toothed part of the first gear, the first toothless part reaches a position confronting the output gear and then the second toothless part reaches a position confronting the second swinging gear.

An assembly of a device having a component, the assembly including a damper having a damper gearwheel coupled to a damper member. The damper member has a first condition restricting motion of the component of the device to a first rate in a first direction and a second condition restricting motion of the component of the device to a second rate in the first direction slower than the first rate. The damper gearwheel is rotationally fixed relative to the damper member when the damper is in the first condition. The damper gearwheel is rotatable relative to the damper member when the damper is in the second condition.

A lifter gear that is engaged with a drive gear when a sheet feeding cassette is mounted, and that releases the engagement with the drive gear when the sheet feeding cassette is dismounted, wherein when the engagement with the drive gear is released and when the lift plate is lowered, braking force caused by frictional force is applied to the lifter gear from a brake unit and a buffer member absorbs force exerted to the lifter gear.

An image forming apparatus includes: an image-forming mechanism; a reconveying roller; an electric motor; and a transmission mechanism. The transmission mechanism is configured to operate in one of a reverse-rotation transmission mode for reversing a direction of a rotational force received from the electric motor to transmit the reversed rotational force to the reconveying roller and a normal-rotation transmission mode for transmitting the rotational force to the reconveying roller without reversing the direction of the rotational force. The transmission mechanism includes an interrupting unit for interrupting transmission of a rotational force from the reconveying roller to the electric motor at least when a sheet is being conveyed in the image-forming mechanism. The transmission mechanism is configured to interrupt transmission of the rotational force received from the electric motor to the reconveying roller when a sheet is being conveyed in the image-forming mechanism.

An image forming apparatus includes: a reconveying unit including a reconveying roller; and a second transmission mechanism. The second transmission mechanism transmits a drive force to the reconveying roller and includes: an input gear; an output gear; an intermediate gear including first and second gears; and first and second swinging gears. The first toothless part of the first gear and the second toothless part of the second gear are provided at such a position that, when the intermediate gear is rotated by a drive force transmitted from the input gear through the second swinging gear while the second swinging gear meshes with the second toothed part of the second gear and the output gear meshes with the first toothed part of the first gear, the first toothless part reaches a position confronting the output gear and then the second toothless part reaches a position confronting the second swinging gear.

The present disclosure provides a drive transmission apparatus including a swing gear mechanism and capable of reducing the workload during assembly and improving efficiency of the assembly operation. A first swing gear, which transmits rotation of a first input gear that is driven by a driving force, is held by a first swing member. The first swing member includes a first engagement potion engaging with a supporting portion, and swings around an axis of the first input gear. The first engagement portion is formed so as to be attached to and detached from the supporting portion if the first swing member is moved in a radial direction with respect to the axis.

A sheet feeding device includes a driving transmission member, a feeding unit, and a switching member. The feeding unit is detachable from the sheet feeding device and includes a driven transmission member that receives a driving force from the driving transmission member, a feeding member, and a holding member that holds the driven transmission member and the feeding member. The switching member abuts the holding member and moves the feeding member between a second position and a first position lowered from the second position. When the driving force is transmitted to the driven transmission member, the feeding unit is positioned to the sheet feeding device by receiving a positioning force in an attachment direction of the feeding unit. When the driving force is not transmitted to the driven transmission member, the feeding unit is regulated by the switching member in movement in a direction opposite to the attachment direction.

A conveyor includes: a first power transmitting mechanism configured to transmit one of forward rotation and reverse rotation of a motor to a first roller and not to transmit the other from a driven member to the first roller; and a second power transmitting mechanism configured to transmit the other rotation to the first roller and not to transmit the one rotation to the first roller. The first power transmitting mechanism includes a transmission delayer that does not transmit rotation of the motor from the driven member to the first roller until the motor is rotated by a particular amount from a time point at which the motor starts to be rotated in a rotational direction of the one rotation when rotation transmitted from the motor to the driven member is changed from the other rotation to the one rotation.

A conveyor includes: a conveyor roller unit including a conveyor roller; a transmission mechanism; a driven roller unit including a driven roller; a supporting member which supports the conveyor roller unit and the driven roller unit to allow the conveyor roller unit and the driven roller unit to take a conveyance position or a retracted position; and a movable member which is movable between a first position where the conveyor roller and the driven roller take the conveyance position and a second position where the conveyor roller and the driven roller take the refracted position. The movable member moves from the second position to the first position when the conveyor roller in the second position rotates in one direction.