Microscope adjustment mechanism with coaxial coarse and fine adjustment shafts and differential screw means

Claim 1

IN A MICROSCOPE, A FRAME HAVING A BASE, AN UPRIGHT PORTION AND AN ARM PORTION OVERHANGING SAID BASE, A STAGE CARRIED BY SAID UPRIGHT PORTION, CARRIAGE MEANS WITHIN SAID FRAME INCLUDING A GENERALLY HORIZONTAL ARM MEMBER RECEIVED WITHIN SAID ARM PORTION OF THE FRAME, AND A LINKAGE ASSEMBLY FIXED TO ONE END OF SAID ARM MEMBER AND DEPENDING THEREFROM WITHIN THE CONFINES OF SAID UPRIGHT PORTION, MEANS SUPPORTING SAID CARRIAGE MEANS FOR VERTICAL SLIDING MOTION WITHIN SAID FRAME, MICROSCOPE OBJECTIVE MEANS SUPPORTED BY THE FREE END OF SAID ARM MEMBER FOR VERTICAL ADJUSTMENT THEREWITH RELATIVE TO SAID STAGE, A BELL CRANK PIVOTALLY MOUNTED WITHIN SAID UPRIGHT PORTION AND ENGAGING SAID LINKAGE ASSEMBLY TO VERTICALLY MOVE SAID CARRIAGE MEANS, AND ADJUSTMENT MECHANISM INCLUDING A CYLINDRICAL CAM WITH WHICH SAID BELL CRANK IS ENGAGED; A COARSE ADJUSTMENT QUILL SHAFT, MEANS SLIDABLY KEYING SAID CYLINDRICAL CAM UPON SAID QUILL SHAFT; A FINE ADJUSTMENT