Abstract: The present invention provides a pivotable optical assembly for a surgical microscope, specifically a zero-degree assistant's device, the assembly comprising: a microscope body interface for mounting the assembly on a microscope body; an assistant's module including an interface for an assistant's tube, the assistant's module being pivotable about a pivot axis relative to the microscope body; and a retaining system that blocks pivoting the assistant's module about the pivot axis. The retaining system comprises: a retaining element being moveable from a locking position into a release position, a biasing member forcing the retaining element into the locking position, and a hand-operable control element acting on the retaining element for moving it from the locking position into the release position, as well as a pivotable optical assembly comprising said retaining system according to the invention, whose retaining element, in its blocking position, blocks pivoting the assistant's module about the pivot axis.

Abstract: The present invention provides a pivotable optical assembly for a surgical microscope, specifically a zero-degree assistant's device, the assembly comprising: a microscope body interface for mounting the assembly on a microscope body; an assistant's module including an interface for an assistant's tube, the assistant's module being pivotable about a pivot axis relative to the microscope body; and a retaining system that blocks pivoting the assistant's module about the pivot axis. The retaining system comprises: a retaining element being moveable from a locking position into a release position, a biasing member forcing the retaining element into the locking position, and a hand-operable control element acting on the retaining element for moving it from the locking position into the release position, as well as a pivotable optical assembly comprising said retaining system according to the invention, whose retaining element, in its blocking position, blocks pivoting the assistant's module about the pivot axis.