JPS641607Y2 - - Google Patents

Description

[Detailed explanation of the invention] In order to keep the surveying instrument in a horizontal state, this invention
This invention relates to a leveling mechanism for a leveling screw attached to a leveling base of a surveying instrument.

As an example of a known adjustment mechanism for the leveling screw of a surveying instrument, as shown in FIGS. Leveling screws 2 are installed at three locations, and the tips of the shaft portions 2a of the leveling screws 2 are supported on the bottom plate 4.
A presser plate contact portion 3 whose upper corner portion has a spherical surface 3a is formed on the shaft portion 2a. A holding plate 5 having a substantially equilateral triangular shape in plan is located between the bottom plate 4 and the leveling screw.
The holding plate 5 has its female threaded cylinder fitting hole 5a fitted into the upper part of the female threaded cylinder 4a for attaching the centering rod provided in the bottom plate 4, and is tightened with a nut 6, and the three parts of the holding plate 4 are The bifurcated portions 5b and 5c are provided by providing inwardly recessed holes 7 at positions corresponding to the two apexes. The width of the strip hole 7 is formed to a width that allows the threaded rod portion 2a of the leveling screw 2 to be inserted therethrough, and the opposing inner walls 5d and 5e of the strip hole 7 are formed as tapered walls in the shape of a square, and the tapered inner walls 5d, 5e is pressed against and supported by the spherical surface 3a of the holding plate contact portion 3 of the leveling screw 2.

Other examples of known leveling screw adjustment mechanisms for surveying instruments include those shown in FIGS. 2 and 6.
In the above-mentioned known example shown in FIGS. 1 and 5, the female threaded cylinder fitting hole 5a of the presser plate 5 is fitted into the upper part of the female threaded cylinder 4a and the bottom plate 4 is not tightened with the nut 6. From the back side of the bottom plate 4, presser plate 5
Nuts 9 and 10 are screwed and tightened onto an adjustment screw 8 that passes through the. 1 in Figures 2 and 6.
The same reference numerals as in FIGS. 4 and 5 indicate the same parts.

In the above-mentioned two known examples, the tapered inner walls 5d, 5e of the forked portions 5b, 5c of the presser plate 5
Since there is no device to properly adjust and maintain the contact pressure between the leveling screw 2 and the spherical surface 3a at the upper corner of the presser plate contact portion 3, it is necessary to adjust the contact pressure by bending the presser plate 5. Not only is the adjustment operation extremely complicated, but also the leveling table 1 must be
When the leveling screw is tilted, the torque of one of the three leveling screws increases, making leveling difficult, especially fine adjustment.

This invention maintains the contact pressure between the presser plate and the corner spherical surface of the presser plate contact area appropriately without requiring complicated operations, and even if the leveling table is tilted with respect to the bottom plate, it can be adjusted to any leveling position. The purpose of the present invention is to provide a leveling mechanism for a leveling screw attached to a leveling stand of a surveying instrument, which allows leveling, especially fine adjustment, to be easily performed without applying a particularly large torque to the screw. That is.

The present invention will be described below with reference to the embodiments shown in the drawings.

Leveling stand 11 of the surveying instrument as shown in Figures 3 and 7
Attach the leveling screws 12 at three symmetrical positions surrounding the female threaded hole 21 for attaching the centering rod.
The tip of the second shaft rod portion 12a is supported on the bottom plate 14. A presser plate contact portion 13 whose upper corner portion has a spherical surface 13a is formed on the shaft portion 12a. A holding plate 15 having a substantially equilateral triangular shape is interposed between the bottom plate 14 and the leveling screw 12. The above presser plate 15
The bifurcated portion 15 is formed by providing inwardly recessed holes 17 at positions corresponding to the three vertices.
b, 15c are provided. The width of the above-mentioned strip hole is formed so that the threaded rod portion 12a of the leveling screw 12 can be inserted therethrough, and the opposing inner walls 15d and 15e of the strip hole 17 are formed as tapered walls in the shape of a square, as shown in FIG. As shown, the tapered inner walls 15d and 15e are supported in contact with the spherical surface 13a at the upper corner of the presser plate contact portion 13 of the leveling screw 12, and the presser plate 15 is provided with a screw hole 22. From the back side of the bottom plate 14, screw the adjustment screw 18 into the bottom plate 14 and the holding plate 15, screw the locking nut 19 onto the tip of the adjustment screw 18, and then screw the locking nut 19 onto the tip of the adjustment screw 18, and then connect the back side of the head 18a of the adjustment screw 18 and the back side of the bottom plate 14. A nut 19 is screwed and tightened onto the tip of the adjusting screw 18 with the disk spring 20 interposed between the screws 18 and 18. 21 is a female screw hole for attaching a centering rod.

In the present invention, when the nut 19 of the adjusting screw 18 is tightened, the presser plate 15 is
The opposing tapered inner walls 15d and 15e of the leveling screw 18 are pressed against the spherical surface 13a of the holding plate support portion 13 of the leveling screw 18, but the pressing force is caused by the elastic force of the disc spring 20. Therefore, the contact pressure can be maintained at an appropriate level.

The leveling base of a surveying instrument must be leveled horizontally regardless of the inclination of the mounting surface of the tripod, etc., and therefore it is necessary to adjust the rotation of the leveling screw, but in this invention, three leveling screws are required. Since the contact pressure between the adjusting screw and each presser plate can be kept constant, the leveling screw is always rotated with a constant torque, making it easy to make fine adjustments when leveling the vial. It has the following effects.

[Brief explanation of the drawing]

Figures 1 and 2 are plan views of known presser plates, and Figure 3 is a plan view of a known presser plate.
The figure is a plan view of the presser plate of the present invention, Figure 4 is Figure 1,
An enlarged vertical cross-sectional view of the X-X' section in Figures 2 and 3,
Fig. 5 is an enlarged vertical sectional view of Fig. 1 Y-Y', Fig. 6 is an enlarged longitudinal sectional view of Fig. 2 Y-Y', and Fig. 7 is an enlarged longitudinal sectional view of Fig. 3.
It is an enlarged longitudinal cross-sectional view of figure YY'. 10... Leveling stand, 12... Leveling screw, 12a...
...Threaded part of the leveling screw, 13... Presser plate contact part, 1
3a... Spherical surface, 14... Bottom plate, 15... Pressing plate,
15b, 15c... bifurcated portion, 15d, 15e...
... Tapered inner wall, 17 ... Strip hole, 18 ... Adjustment screw, 18a ... Adjustment screw head, 19 ... Nut, 20 ... Belleville spring, 21 ... Centering rod mounting screw hole, 22 ... screw hole.

Claims (1)

[Scope of utility model registration request] The tip of the screw of the leveling screw provided on the leveling base of the surveying instrument is supported on the bottom plate, and the presser plate interposed between the bottom plate and the leveling screw has a bifurcated tapered inner wall. In the leveling screw adjustment mechanism of a surveying instrument, the adjustment mechanism for the leveling screw of a surveying instrument is provided with a screw hole in the presser plate, and the tapered inner wall of the forked portion is supported by a presser plate support portion provided on the threaded rod portion, and a screw hole is provided in the presser plate, and the back surface of the bottom plate is The structure consists of a presser plate screwed together with an adjustment screw, a locking nut screwed together, and a spring interposed between the head of the adjustment screw and the bottom plate.