JPH07260478A - Survey machine - Google Patents

Abstract

PURPOSE:To prevent static electricity charged to a cover from affecting a compensation device by mounting a conductive shielding plate so that the pendulum of the compensation device is covered between a synthetic resin cover fitted to the opening of a mirror cylinder and the compensation device and by connecting the shielding plate to the mirror cylinder. CONSTITUTION:A synthetic resin cover 13 is inexpensive but can be easily charged since it is exposed externally and hence the static electricity prevents normal operation of a horizontal compensation device 30. However, by providing a conductive shielding plate 23 between the cover 13 and the compensation device 30, the generated static electricity escapes to a mirror cylinder 12 via a suspension frame 22 even if the shielding plate 23 is electrified, thus preventing the compensation device 30, especially a damping plate 34 from being affected. The shielding plate 23 can be mounted simply by fixing four corners of the rectangular shielding plate to the upper edge of the suspension frame 22 with fixing screw 28, thus reducing cost as compared with a case when a conductive metal is used for the cover 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surveying instrument having a compensating device arranged to keep the collimation axis horizontal when the telescope barrel is tilted with respect to the horizon.

[0002]

2. Description of the Related Art Conventionally, as a surveying instrument, there is known a surveying instrument having a correcting device configured to keep the collimation axis horizontal even when the barrel of the telescope is inclined with respect to the horizontal line. This correction device has a pendulum composed of an optical member suspended by a plurality of strings (strip-shaped plates). When the lens barrel is tilted from the horizontal position, the optical path between the objective lens and the eyepiece lens is changed by the optical member. It is bent, which keeps the collimation axis horizontal.

In such a surveying instrument, a cover, which is provided above the correcting device and closes the opening of the lens barrel, is often molded from synthetic resin in order to reduce weight and cost. However, since the cover is exposed to the outside, there are many opportunities for friction to occur on the surface, and in the case of ordinary synthetic resin,
Static electricity is easily charged. This static electricity prevents normal movement of the pendulum in the correction device. As a countermeasure, Japanese Utility Model Publication No. 4-48490 proposes a structure in which a conductive film is formed on the inner wall surface of a synthetic resin cover by painting or plating.

[0004]

However, there is a problem that the manufacturing process of the cover having such a conductive film is complicated and the manufacturing cost is high. On the other hand, it is possible to use a conductive resin material for the cover itself, but since the conductive resin material is inferior in appearance to general resin materials, it is necessary to apply cosmetic coating on the surface, resulting in cost reduction. There is a problem that it takes.

The present invention has been made in view of the above problems, and prevents static electricity charged on the cover from affecting the correction device and is easy to manufacture.
It is an object of the present invention to provide a surveying instrument whose manufacturing cost can be kept low.

[0006]

A surveying instrument according to the present invention comprises:
A correction device that is provided in the barrel of the telescope and that keeps the collimation axis horizontal even when the barrel tilts with respect to the horizontal line,
The cover is made of a synthetic resin attached to the opening of the lens barrel, and the conductive blocking plate is provided between the cover and the correction device to cover the pendulum of the correction device. It is characterized in that the blocking plate is electrically connected to the lens barrel.

[0007]

The present invention will be described below with reference to illustrated embodiments. 1 is a partial sectional view of a surveying instrument according to a first embodiment of the present invention. This surveying instrument has a lens barrel 12, and measures the angle and distance from the horizontal line. The lens barrel 12 has a cylindrical shape, and is formed of a conductive metal or the like in order to maintain the accuracy of assembling internal parts and the like. The reflection prism 15 and the reflection roof prism 16 are fixed to a suspension frame 22 of a pendulum 30 described later, and an eyepiece lens 14 is provided at one end of the lens barrel 12. An opening 12a is formed in the lens barrel 12, and a cover 13 is attached to the opening 12a. Cover 13
Is molded from a non-metallic synthetic resin or the like to reduce the weight and cost.

The correction device 21 is provided in the lens barrel 12 at a position below the cover 13. The configuration of the correction device 21
This will be described with reference to FIGS. 2 is a perspective view of the correction device 21, and FIG. 3 is a sectional view of the correction device 21.
2 and 3, the reflecting prism 15, the reflecting roof prism 16 (FIG. 1) and the like are omitted in order to simplify the description.

The suspension frame 22 is fixed to the lens barrel 12 via screws 17, and a conductive blocking plate 23 is fixed to the upper end of the suspension frame 22 with fixing screws 28. An opening 22a is formed in the suspension frame 22, and a magnet mounting frame 24 is fixed to the conductive blocking plate 23 in the opening 22a. The magnet mounting frame 24 is formed in a U shape, and both legs of the magnet mounting frame 24 extend downward. Magnets 25 are attached to both legs of the magnet mounting frame 24.
Are fixed, and these magnets 25 face a braking plate 34 described later. The suspension frame 22 and the conductive blocking plate 23 are formed of a conductive metal material, a conductive resin material, or the like, and are electrically connected to the lens barrel 12 via the suspension frame 22.

The pendulum 30 is a suspension band 2 connected to a suspension frame 22.
6, it is suspended with respect to the suspension frame 22 on the basis of the gravity direction. The pendulum 30 has a bottom portion 31 and a support portion 33 extending upward from the bottom portion 31. A suspension mirror 32 is attached to the bottom portion 31 substantially horizontally, and the suspension mirror 32 reflects the optical axis incident from the reflection prism 15 (FIG. 1) and bends it toward the reflection roof prism 16 (FIG. 1). .

The braking plate 34 is formed of a material having an extremely high electric conductivity such as copper, and is fixed to the supporting portion 33 with a screw 35. The braking plate 34 is usually located at a substantially equal distance from each of the facing magnets 25. A limiting plate 27 is attached to the suspension frame 22, and the adjusting screw 27 a screwed to the limiting plate 27 extends toward the support portion 33 of the pendulum 30. The tip of the adjusting screw 27a faces the support portion 33 with a predetermined gap, and restricts the movement of the pendulum 30 in the direction toward the magnet 25.

When this surveying instrument is installed horizontally with respect to the ground, the optical path of the incident light beam of the object incident from the objective lens (not shown) in FIG. After being bent by the mirror 32, the light enters the eyepiece lens 14. On the other hand, when the surveying instrument is installed with a slight inclination and the lens barrel 12 is inclined with respect to the horizontal line, the suspension mirror 18 is inclined by a predetermined amount from the reference position, whereby the optical path of the incident light beam is changed and collimation is performed. The axis is kept horizontal. Since this operation is conventionally known, its description is omitted.

When the surveying instrument vibrates, the pendulum 30 also tends to vibrate. However, if the braking plate 34 of the pendulum 30 is the magnet 2
When vibrating in a direction parallel to the direction 5, a line of magnetic force generated between the pair of magnets 25 is crossed vertically, so that an eddy current is generated in the braking plate 34. This eddy current damps the movement of the braking plate 34, resulting in a magnet damper effect. This magnet damper effect suppresses the vibration of the pendulum 30 in the direction parallel to the magnet 25. Further, the vibration of the pendulum 30 in the direction toward the magnet 25 is suppressed by the support portion 33 coming into contact with the adjusting screw 27a. As described above, the operation of the pendulum 30 is stable, and good surveying is performed.

Since the cover 13 is exposed to the outside of the surveying instrument and is made of synthetic resin, it is easily charged with static electricity. However, due to this static electricity, the conductive blocking plate 2
Even if 3 is charged, the static electricity generated in the conductive blocking plate 23 escapes to the lens barrel 12 via the suspension frame 22, so that the correction device 30 (particularly the braking plate 34) may be affected by the static electricity. Instead, a good correction of the collimation axis is performed.

To mount the conductive blocking plate 23, the four corners of the rectangular conductive blocking plate 23 are fixed to the upper end of the suspension frame 22 by the fixing screws 2.
It is extremely easy because it only needs to be fixed at 8. The conductive blocking plate 23 is not particularly limited as long as it is conductive,
In addition, it is not necessary to attach it with high precision. Therefore, a commercially available material can be used, and the manufacturing cost can be kept low. Further, since the magnet mounting frame 24 to which the magnet 25 is mounted is fixed to the conductive blocking plate 24, the structure of the magnet mounting frame 24 can be made very simple and the manufacturing cost can be kept low.

FIG. 4 is a partial sectional view of a surveying instrument according to a second embodiment of the present invention, FIG. 5 is a perspective view of the correction device 21, and FIG. 6 is a sectional view taken along line VI-VI of FIG. FIG. The configuration of the second embodiment will be described with reference to FIGS. The same or corresponding parts as those in the first embodiment are designated by the same reference numerals, and the duplicated description will be omitted.

In the second embodiment, the balance weight 35 is attached to the upper end of the braking plate 34. The conductive blocking plate 23 is formed into a truncated cone shape so as to cover the balance weight 35, and is attached to the suspension frame 22 with a fixing screw 28. The magnet mounting frame 24 has a horseshoe shape, and is composed of an arc-shaped intermediate portion 24a and bent portions 24b that are bent outward at both legs.
It is fixed to the suspension frame 22 at 4b.

In the surveying instrument of this embodiment, the same effect as that of the first embodiment is obtained, and in addition, the step of attaching the conductive blocking plate 23 and the magnet 25 and the magnet attachment frame 24 are also provided.
The magnet 25 can be attached more easily because the attaching step is a separate step.

[0019]

As described above, according to the present invention, it is possible to provide a surveying instrument that prevents static electricity charged on the cover from affecting the correction device, is easy to manufacture, and is low in manufacturing cost. You can

[Brief description of drawings]

FIG. 1 is a partial sectional view of a surveying instrument according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a correction device of the surveying instrument of FIG.

FIG. 3 is a sectional view of a correction device of the surveying instrument of FIG.

FIG. 4 is a partial sectional view of a surveying instrument according to a second embodiment of the present invention.

5 is a perspective view of a correction device of the surveying instrument of FIG. 4. FIG.

6 is a sectional view taken along line VI-VI of 5 in FIG.

[Explanation of symbols]

 11 Telescope 12 Lens Tube 12a Opening 13 Cover 21 Corrector 23 Conductive Blocking Plate 30 Pendulum

Claims (3)

[Claims] 1. A correcting device provided in a lens barrel of a telescope, for keeping the collimation axis always horizontal even when the lens barrel is tilted with respect to a horizontal line, and a correction device mounted in an opening of the lens barrel. A cover made of synthetic resin and a conductive blocking plate provided between the cover and the correction device and provided so as to cover the pendulum of the correction device are provided, and the conductive blocking plate is attached to the lens barrel. A surveying instrument characterized by being electrically connected. 2. The surveying instrument according to claim 1, wherein a magnet that suppresses vibration of a pendulum of the correction device is attached to a lower surface of the conductive blocking plate. 3. The surveying instrument according to claim 1, wherein the blocking plate is made of a metal material or a conductive resin material.