| 摘要 |
The measurement prods (15) are controlled by moving equipment constituted by an axially moving rod (7a), on which a cylinder (11a) can slide, which cylinder is subjected to the action of a main spring (13) which pushes it towards a position in which it bears against a stop (19) integral with the rod (7a). This rod is furthermore pushed by a second, weaker spring (16) which acts in the opposite direction to the main spring. The trigger (17) which makes it possible to act on the cylinder (11a) can be actuated as far as its end of travel without the rod (6) of the comparator fixed to the body (1, 2) of the instrument ever being subjected to a pressure greater than the force of the second spring (16). This makes it possible to avoid the drawback of direct action of the trigger on the part of the moving equipment which acts on the feeler (10) of the comparator, and which can by virtue of this fact cause sliding of this rod in the tightening bush (4) and consequent reading errors. <IMAGE>
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