Patent ID: 8414434

Claim:
A transmission device for a cycle, said device comprising: a bottom bracket fixed relative to a cycle frame, said bottom bracket including a cylindrical main body centered about a first axis and a secondary body centered about a second axis, said second axis being parallel to, but not merged with, said first axis; a crankset rotationally mounted along the first axis relative to the main body, said crankset comprising: a pair of cranks; a first circular toothed element centered on the first axis; a second circular toothed element centered on the first axis; a chainwheel rotationally mounted along the second axis relative to the secondary body, said chainwheel comprising: a third circular toothed element centered on the second axis; a fourth circular toothed element centered on the second axis; said first and third toothed elements constituting a first gear train and said second and fourth toothed elements constituting a second gear train; at least one of said first, second, third and fourth toothed elements having radially internal teeth; a disengageable blocking device to block selectively the following: rotation of the first toothed element relative to the crankset or rotation of the third toothed element relative to the chainwheel; and rotation of the second toothed element relative to the crankset or rotation of the fourth toothed element relative to the chainwheel.