A lot of rackmount server case are equipped with hot-swappable tray. Rackmount case brand might have different design of hot-swappable tray but the mechanical engineering can be actually or almost the same.
I have no experience with engineering and the prototype will probably be built by Manufacturer in China. The engineer will come up with the the locking mechanism design somehow.
Does the locking mechanism has to be different that is not patented? but the tray design will be quite different.