The Janney/knuckle coupler was patented in 1873, so it's use would have started from shortly before then. The transition was slow at first and really picked up in the late 1880s, and knuckle couplers were mandated by 1906.The original Janney knuckle was designed with the link slot for the transition, and you can still see these knuckles in limited use at various museum operations, so the actual use period is now almost 150 years. IIRC the Miller Hook couplers (appeared late 1860s - 1890s) also accepted links, so the split Janney knuckles could also be used for towing those equipped cars (mostly passenger equipment).
Side note - In the pic you used, the coupler body is marked AAR and looks more like a type E or very late D, and the AAR didn't exist before 1934, so it wasn't made until at least 28 years after link and pin couplers were outlawed. Later (post 1906/7) transition knuckle revenue users would have been logging roads, traction roads, industries and other special users, not mainline RRs.
