JPH0247452Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] The invention of this application relates to an improvement of an alidade used for flat surveying. As shown in Fig. 4, the conventional alidade has collimating plates 2a and 2b foldably attached to the front and rear ends of a base 1, respectively, and a collimating thread 3 is provided on the front collimating plate 2a. Further, an extraction plate 5 having a collimating hole 4 is fitted into the rear collimating plate 2b so as to be able to be pulled out in the vertical direction. With this type of alidade, the sighting hole 4 is only on one sighting plate and not on the other sighting plate, so during surveying work, the sighting plate with this sighting hole is located in front of the surveyor. Therefore, the surveyor has to identify which of the two sighting plates has the sighting hole, and this hassle is caused by the need for a large number of survey points. This cannot be ignored, especially when surveying is required.

In order to eliminate such trouble, the invention of this application aims to provide an alidade that allows normal work to be carried out without the need to distinguish between the front and rear sighting plates, regardless of whether they are located in front of the surveyor. That is.

[Structure of the idea]

As shown in FIGS. 1 to 3, the embodiment according to the invention of this application has collimating plates 2a and 2b attached to the front and rear ends of a base 1 so as to be foldable with respect to the base. Each of the quasi-plates 2a and 2b has a central part missing in the longitudinal direction, and the whole is approximately U-shaped, and there is an elongated extraction plate 5 therein.
a and 5b are fitted together so that they can be taken in and out. The two extraction plates 5a, 5b have substantially the same structure, that is, the extraction plates 5a, 5b have holes elongated in the longitudinal direction, ie, elongated holes 6a, 7a, 6b, as shown in FIGS. 1 to 3. , 7b are formed in a row, and in each of the elongated holes, a collimating thread 3a, 3a, 3b, 3b is connected to an extraction plate 5a, 5b.
It is stretched in the longitudinal direction. Further, the long holes 6a, 7a of the extraction plates 5a, 5b and the long holes 6b, 7
There are collimation holes 4 in the part between b and the upper and lower ends of the extraction plate.
a and 4b are provided.

Next, the usage mode of the alidade according to this invention will be explained. If the sighting plate in front of the surveyor is the left sighting plate 2b in the example of FIG. When the pole (not shown) at a distant survey point is seen through the sighting hole 4b, it is pulled out so as to be at an appropriate height for the surveyor, or without being pulled out, and fitted into the front sighting plate 2a. The alidade base 1 is moved on a flat plate (not shown) so that the collimating thread 3a of the extracting plate 5a that is being aligned is on the center line of the pole. In that case, the pole is the extraction plate 5a
When the field of vision is obstructed in the area between the elongated holes 6a and 7a, that is, the area near the collimating hole 4a, as shown in FIG.
By pulling it out from the collimation hole 4b, it becomes possible to see through the long hole 6a or 7a of the extracting plate 4a to a distant pole. And sight hole 4b
When the sight line 3a is positioned on the center line of the pole when looking at the far pole from the center, the direction of the base 1 is facing the survey point, so the subsequent work is different from that using the conventional alidade. do not have. That is,
The actual distance between the flat plate installation position and the survey point is drawn at a predetermined scale using the ruler 8 of the alidade base 1.

The above example shows the case when looking through the sighting hole 4b of the extraction plate 5b fitted to the sighting plate 2a, but since both sighting plates have substantially the same structure, the other sighting plate 2a It is easily understood that the same is true when looking through the collimation hole 4a of the fitted extraction plate 5a.

[Effect of idea]

As mentioned above, if the alidade of this invention is used, it has both sighting holes and sighting threads on both sighting plates, so when capturing a large number of survey points on a flat plate, it is possible to measure them one by one as before. This eliminates the trouble of identifying the sighting plate with the sighting hole and bringing it to the front, which contributes to improving the efficiency of surveying work.

In addition, the ruler 8 attached to the alidade base 1
may be provided only on one side of the base as in the conventional case, or may be provided on both sides of the base. When rulers 8 are provided on both sides of the base, two collimating plates 2
The advantage is that you can always draw a line using the ruler on the right side, no matter which one is in front of you, a or 2b. In addition, in the embodiments shown in FIGS. 1 to 3, extraction plates 5a, 5b
Although two elongated holes are formed, the number should not be limited to two, and may be three, for example. Furthermore, as shown in FIG. 1 or 2, if scales are attached to both the collimation plate and the extraction plate, stadia surveying can be carried out, similar to the conventional alidade.

[Brief explanation of the drawing]

1 and 2 are perspective views of an alidade according to the present invention. Figure 3 is a top view of this alidade when folded. FIG. 4 is a perspective view of a conventional alidade. 1... Alidade base, 2a, 2b... Sighting plate, 3a, 3b... Sighting thread, 4a, 4b... Sighting hole, 5a, 5b... Extraction plate, 6a, 7a, 6b,
7b... Long hole, 8... Ruler.

Claims (1)

[Scope of utility model registration request] In the case where extraction plates 5a and 5b are removably fitted to two front and rear collimation plates provided on the alidade base 1, each of the extraction plates 5a and 5b has a plurality of elongated holes 6a, 7a, 6b, and 7b. They are formed in a line in the longitudinal direction, and collimating threads 3a, 3b are stretched in the center of each of the elongated holes, and elongated holes 6a, 6b of the extraction plates 5a, 5b
A collimating hole 4a is provided between the long holes 7a and 7b.
An alidade for flat plate surveying formed with 4b.