Model: Z07 Cone Coupling
This is a two parallel shaft mechanism driven by a spur gear pair. The second shaft is engaged by a truncated cone fitted into the inside rim of the driven shaft. The cone and rim are brought together with a hand actuated nut and screw pair. According to Reuleaux in his 4th edition of The Constructor, the cone angle "should not be taken at less than 10 degrees, in order that the parts may not become wedged together." When the conical surfaces are engaged, the crank on one shaft will drive the crank on the other shaft.

Francis Moon 2004-10-25

Reference :