Patent ID: 7669496

Claim:
A driving force transmission apparatus comprising: a driving gear which rotates by receiving a driving force from a driving source; a driven gear which rotates by rotation of said driving gear; a toothed clutch which transmits the driving force from said driving source from said driving gear to said driven gear, the toothed clutch including a driving-side ratchet and a driven-side ratchet engageable with the driving-side ratchet and movable between a first position and a second position in an axial direction of the toothed clutch, the first position being a position in which the driven-side ratchet completely engages with the driving-side ratchet in the axial direction of the toothed clutch, the second position being a position in which a tip end of a pawl of the driven-side ratchet is located at a position which is the same as a tip end of a pawl of the driving-side ratchet in the axial direction of the toothed clutch, and a biasing member which biases the driven-side ratchet toward the driving-side ratchet, wherein, when the driven-side ratchet is located at the second position, a biasing force by the biasing member acts on the driven-side ratchet, and when the driven-side ratchet is located at the first position, the biasing force by the biasing member does not act on the driven-side ratchet.