Abstract: In a microscope, a nosepiece support assembly and a coarse and fine adjustment mechanism in direct operative control of the support assembly, the support assembly including a nosepiece mounting carriage with a depending rod rigid therewith and mounting a cam follower which rides on the edge of a cam, rotation of which is controlled by the adjustment mechanism. The adjustment mechanism in turn includes a reduction gear assembly utilizing dual gear trains and mounted to a cam-mounting shaft externally of the frame of the microscope and housed within a coarse adjustment handwheel for immediate access thereto. One of the gear trains incorporates a compound gear having a torsion spring between the individual gears to enhance gear train interengagement throughout the gear assembly.

Abstract: In a microscope, a nosepiece support assembly and a coarse and fine adjustment mechanism in direct operative control of the support assembly, the support assembly including a nosepiece mounting carriage with a depending rod rigid therewith and mounting a cam follower which rides on the edge of a cam, rotation of which is controlled by the adjustment mechanism. The adjustment mechanism in turn includes a reduction gear assembly utilizing dual gear trains and mounted to a cam-mounting shaft externally of the frame of the microscope and housed within a coarse adjustment handwheel for immediate access thereto. One of the gear trains incorporates a compound gear having a torsion spring between the individual gears to enhance gear train interengagement throughout the gear assembly.