Patent ID: 8315542

Claim:
A power transmission apparatus for transmitting driving power from a driving power source to at least first and second movable members of an image forming apparatus, the driving power being a bi-directional rotational power in first and second directions of rotation, the power transmission apparatus comprising: a bi-directional power conveyance mechanism to receive a driving power from the driving power source; a driving unit configured to receive the driving power transmitted from the bi-directional power conveyance mechanism and to convey the driving power to the first movable member so as to cause the first movable member to rotate in the first and second directions; a driven unit coupled to the second movable member; and an elastic clutch provided directly between and in contact with both the driving unit and the driven unit to selectively couple the driving unit and the driven unit, the elastic clutch being configured to elastically couple the driving unit and the driven unit to allow the driven unit to receive the driving power from the driving unit, and to transmit the driving power to the second movable member to cause the second movable member to rotate in the first direction when the driving power is in the first direction, the elastic clutch being further configured to decouple the driving unit and the driven unit when the driving power is in the second direction so that the driving power in the second direction is not transmitted to the second movable member.