Coarse adjustment and fine adjustment linear moving mechanism

Abstract

The invention relates to a coarse adjustment and fine adjustment linear moving mechanism which comprises a fixed seat, a movable seat, a coarse adjustment screw bar and a fine adjustment toothed bar, wherein the fixed seat is provided with a first screw hole; the movable seat is movably arranged on the fixed seat and provided with a second screw hole; the coarse adjustment screw bar is provided with a threaded section and a smooth section; the threaded section is screwed with the first screw hole; and the fine adjustment toothed bar is rotatably sleeved on the smooth section of the coarse adjustment screw bar and screwed in the second screw hole. Therefore, a user can respectively rotate the coarse adjustment screw bar and the fine adjustment toothed bar to enable the movable seat to quickly move or finely move, and because the two movements are respectively driven by the coarse adjustment screw bar and the fine adjustment toothed bar with different thread pitches, the fast-moving speed and the fine-moving accuracy can be compromised.

Description

technical field [0001] The present invention relates to a linear movement mechanism, in particular to a linear movement mechanism that allows a user to manually adjust the position of a platform and can take into account both movement speed and accuracy. Background technique [0002] Manual linear movement mechanism has been widely used in microscopes, measuring machines and machine tools. The known linear movement mechanism with coarse and fine adjustment functions, as disclosed in U.S. Patent No. 4,919,001, includes a base block, a moving platform (stage) and a feed screw shaft, and the screw rod is rotatable The way is set on the base, and engaged with a stage supporting member (stage supporting member) on the bottom side of the mobile platform. When it is necessary to move the platform quickly, the user can use a coarse adjustment handle to rotate the screw to drive the platform to move linearly; when it is necessary to move the platform finely, the user needs to rotate...

AI Technical Summary

Problems solved by technology

[0003] The linear movement mechanism is driven by the same screw regardless of coarse adjustment or fine adjustment. If the pitch of the screw is too small, the moving speed of the platform during coarse adjustment will be very slow, so the user needs to rotate a considerable number of turns to move the platform. Move to the desired position, and if the pitch of the screw is too large, the backlash between the external thread of the screw and the internal thread of the platform support will be relatively enlarged, so that the rotation of the fine-tuning knob cannot fully reflect the movement of the platform support , thus reducing the accuracy of fine movements

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