>>9437682https://worldwide.espacenet.com/patent/search/family/065036768/publication/EP3737481A1?q=pn%3DEP3737481A1>A toy gearbox comprising at least one gear shaft (1, 2) rotatably supported by a gear support construction and having at least one spline, and at least one gear wheel (21, 22, 23, 24) rotatably arranged on the gear shaft (1, 2), a first clutch member (50) being attached to the gear wheel (21, 22, 23, 24) and rotatably arranged on the gear shaft (1, 2) and a second clutch member comprising a driving ring (41, 42) being fixed against rotation about and slidably arranged on the gear shaft (1, 2) and comprising a guide member (45) and at least one claw clutch (46, 47) for selectively engaging or disengaging with the first clutch member (50) and thereby engaging or disengaging the gear wheel (21, 22, 23, 24) from rotating along with the gear shaft and where an axial cam (10) arranged on a gear shifter axle (11) being mounted in the gear support construction and having an axis of symmetry extending parallel with the gear shaft (1, 2), so that the guide member (45) on the axially slidable driving ring (41, 42) engages with the axial cam (10).tl;dr
Selling models that infringe this patent isn't a good idea. The CaDA Master sets can't be sold anymore. Shops aren't willing to take the risk and it's close to impossible to find certain sets.
