R-4104.A
MECHANISM ANO PRINCIPLE | 1. Coaxial Coarse and Fine Focus Unit |
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2)Transmission of turning force of coarse focus knob
e No drop of the stage, which otherwise would occur while the coarse and fine focus knob is not operated, is due to the friction giVen by the spring (@) to the coarse focus knob, in the sarne way as in the case where the rotation force, produced under the weight of the stage and substage, even reduced through the whole system of gears, to tum the fine focus knob, is surmounted by the friction caused by the spring ( (@).
•ln such a situation, when the coarse and fine focus knob (@ or C@3) ) is turned,
since no relative rotation between the coarse and fine focus knobs will take place, thus the gears @. @. @, @ will not rotate on their axis in the coarse
focus mechanism, but make the sarne rotation as the coarse focus knob, i.e. a revolution round the center of the pinion shaft.
•Therefore, when the coarse focus knob is turned, the gear @ will make the sarne rotation as the coarse focus knob causing rotation to the pinion with the reduction ratio @ to @, @ to @.
Furthermore, in the staying position, even though the stage does not drop under its weight. the coarse focus knob will be moved by the tuming of the fine focus knob.
This is on account of the fact that the change of the rotation force as well as the friction factor in the rotation position differ from those in the staying position owing to lubricant or the like.
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