The coupling for the ends of two shafts (1,2) rotating on a common axis (X-X) comprises a tooth (5) and a notch (6) fixed respectively to the two shaft ends. They extend perpendicular to the common axis and have conjugate sections so that the tooth engages in the notch. A sleeve (3) surrounds the shaft ends and has two support ends (24,25) perpendicular to the axis. A spring (4) inside the sleeve is supported on one (25) of the sleeve end faces connected to one (1) of the shafts. The spring applies the shaft ends against the other end support face of the sleeve. A hub (26) and a slot (29) enable a pin (33) mounted in the shaft to pass through the slot and hold the sleeve in place during engagement of the tooth in the notch. <IMAGE>
