Seat-back tilting device

The invention concerns a seat-back tilting device, comprising a tilt control handle (1a, 1b) that can be chosen from a first control handle (1a) and a second control handle (1b), and a tilt control shaft (2) on which the control handle (1a, 1b) is arranged, characterised in that the control shaft (2) comprises: - an area (21) for receiving a first return member (15) combined with the first control handle (1a), - an area (22) for receiving a second return member (14) combined with the second control handle (1b), and - an area (23) for transmitting forces from the first control handle (1a) and from the second control handle (1b).