Troubleshooting for the Condenser Lifting Mechanism of the Microscope
(1) The condenser lifting mechanism of the straight-tube microscope is shown in Figure 10-3-2: 1, 5. Celluloid washers 2. Round-head screw 3. Eccentric toothed rod sleeve 4. Toothed rod 6. Lifting handwheel 7. Double-eye nut
For adjustment: Insert the double-eye nut wrench into the double-eye nut on the end face of the handwheel with one hand, and insert a screwdriver into the slot of the round-head screw at the other end with the other hand. Tighten firmly to stop self-slipping.
(2) The condenser lifting mechanism of the inclined-tube microscope is shown in Figure 10-3-3:
For adjustment: First, back off the setscrew 2 in the middle of the double-eye nut by 1–2 turns with a screwdriver. The bearing washer 3 is press-fitted with the setscrew 2, so it will back off together and separate from the end face of the toothed rod 10. Next, screw the double-eye nut 1 inward toward the adjusting seat 5 using the double-eye nut wrench. At the same time, turn the handwheel with the other hand for testing. Stop turning the double-eye nut once the lifting mechanism has proper tightness and can hold any position. Finally, screw the setscrew back in until the bearing washer contacts the toothed rod 10.
This adjustment resolves the fault because the inner bore of the adjusting seat 5 is tapered. The tapered shaft sleeve 4 has axial slots, as shown in Figure 10-3-4. When the double-eye nut 1 is screwed inward, it pushes the tapered sleeve forward. As the sleeve advances, its slots narrow and the inner bore contracts, clamping the toothed rod 10 more tightly. This increases the frictional resistance against gear rotation and prevents automatic downward movement.
