Pivotable optical assembly for a surgical microscope, in particular 0DEG-assistant's device, and a retaining system therefor

The present invention relates to a pivotable optical assembly (1) for a surgical microscope, in particular a zero-degree assistant's device (2), the assembly comprising: a microscope body interface (3) for mounting the assembly (1) on a microscope body; an assistant's module (5) including an interface (6) for an assistant's tube, the assistant's module (5) being pivotable about a pivot axis (11) relative to the microscope body (3); and a retaining system (7) that blocks pivoting the assistant's module (5) about the pivot axis (11). The present invention furhter relates to a retaining system (7) for such pivotable optical assembly (1) of a surgical microscope. In order to provide a pivotable optical assembly for a surgical microscope and a retaining system therefor, that allows the assistant to change sides quickly, easily and without the requirement of separate equipment, the invention provides a retaining system (7) comprising a retaining element (12) being moveable from a locking position (L) into a release