R.4104.A
MECHANISM ANO PRINCIPLE | 1. Coaxial Coarse and Fine Focus Unit |
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MECHANISM ANO PRINCIPLE
1. Coaxial Coarse and Fine Focus Unit
Fig. 24
1)Transmission of turning force of fine focus knob
e Tuming force of the fine focus knob ( C@D or @> is transmitted to the pinion
shaft ( (@) to move the rack (®) vertically through the gear system (@ , @ ,
@.@. ®· @,@, @, @),@).
eln this transmission with such a reduction ratio as from @ to @ , the weight of the stage and substage, which exerts force to rotate @ , is overcome by the friction offered by spring (e[!])) to the sliding surfaces of @ and @ .
eThus, even though some backlash is provided for each gear to enable smooth gearing, almost no slack will be seen in the rising and lowering directions of the stage, by virtue of the rotation force of the gears work.ing in one direction under the wetght of the stage.
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