Microsurgical operating unit

A microsurgical operating unit including a vertical support column mounted at its upper end at the ceiling of a room such as an operating theater, a sleeve rotatably supported on said vertical support column, a pivot arm for height adjustment, said pivot arm being rotatably mounted about a horizontal pivot axis disposed adjacent the free lower end of said sleeve, a vertical pendulum arm rotatably mounted at the free lower end of said pivot arm, a microscope mounted at an articulation on the free lower end of said pendulum arm, a pivot mounting for horizontal alignment of said miscroscope being interposed between said articulation and a microscope mounting, and a parallelogram-type control linkage including a chain drive for maintaining the microscope in a vertical orientation in any rotational position of said pendulum arm, with the pivot axes of said pivot arm, said pendulum arm pivot on said pivot arm, and said articulation pivot of said microscope on said pendulum arm all being arranged parallel to each other, with a first sprocket and said microscope mounting being rigidly secured to the articulation axis on the free lower end of said pendulum arm for alignment of said microscope in a vertical position during rotation of said pendulum arm, a second sprocket operatively coupled by a chain to said first lower sprocket, said second sprocket being rigidly secured to a shaft, said shaft being rotatably journalled in an upper articulation between said vertical pendulum arm and said pivot arm and operatively coupling said pivot arm to said pendulum arm, a lever secured to a projecting portion of said shaft, a connecting rod rotatively connected at its one end to the free end of said lever, and rotatably connected at its opposite end to a fixed pivot point on said sleeve rotatably mounted on said support column, said pendulum arm consisting of a hollow cylindrical member, said chain extending along the interior of said hollow cylindrical pendulum arm whereby said lever, said connecting rod and said chain form part of said parallelogram-type control linkage for said microscope.