| 摘要 |
A crank arm ( 1 ) is provided that is connected to the crank head ( 2 ) through an elastic rotation axis ( 6 ) and a lock axis ( 7 ) having a reduced diameter (D) in the middle of said lock axis ( 7 ), the crank arm ( 1 ) also comprises a lock device ( 4 ) that is connected to the push button ( 5 ) and both together are easily moved down and upward with the user's thumb to release and lock the crank arm ( 1 ) between its operative and folded position, when the lock device ( 4 ) is pulled down a retaining spring ( 3 ) is compressed allowing the upper end of the lock axis ( 7 ) to flush with the crank arm hole (H) and releasing the crank arm ( 1 ) to rotate freely along its longitudinal plane with a 180° rotation angle in relation to the elastic rotation axis ( 6 ), by releasing the lock device ( 4 ) to its upper position it will lock the crank arm ( 1 ) at its folded position, then the fixation of the pedal-sprocket on the head crank ( 2 ) is performed by means of a fastening nut ( 5 ) which fix the crank head ( 2 ) to any commercially available pedal-sprocket. |
