JP3515497B2 - Surveying tripod - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a tripod for a surveying instrument.

[0002]

2. Description of the Related Art As a conventional tripod for a surveying instrument, three extendable leg portions, a leg head for swingably connecting the upper ends of the three leg portions, and a leg head attached to the upper surface of the leg head. It was known to have a level of In the case of this tripod, a plumb bob is hung on the lower surface of the leg head at the survey site,
A leveling instrument called a mover is attached to the upper surface of the leg head, and a surveying instrument is attached to the upper surface of the mover for assembly. Then, while positioning the plumb bob at a fixed point, while watching the level, each leg is expanded and contracted to set the upper surface of the head of the leg almost horizontally, and the mover is used to finely adjust the surveying instrument so that it is closer to horizontal. , The final perfect leveling will be done by adjusting the screw of the surveying instrument, and the preparation for surveying will be completed, but since the tripod installation is in consideration, if the levelness of the leg head is poor, the range of fine adjustment As a result, the tripod will be exceeded, and the tripod will often be re-installed so that the tripod is closer to the fixed point.

[0003]

The work of installing a tripod at a fixed point requires a high degree of skill and intuition, but in a conventional tripod for a surveying instrument, a level gauge is used because a mover is attached to the upper surface of the leg head. It was hard to see, and there was a problem that even an expert would take time. In addition, there is a problem that the cost is high because a moving device having a complicated and precise structure is required.

Therefore, the present invention does not require a high degree of skill,
Moreover, it is an object of the present invention to provide a tripod for a surveying instrument that can be used at low cost without the need for any other leveling device.

[0005]

In order to achieve the above-mentioned object, a tripod for a surveying instrument according to the present invention holds three legs and the upper ends of the three legs in a swingable manner. A tripod for a surveying instrument having a leg head, and a level level attached to the outer surfaces of the upper ends of the three leg portions.

Further, a horizontal adjustment mechanism for finely adjusting the upper surface of the leg head to a horizontal state is provided at the lower end of at least one leg, and the horizontal adjustment mechanism is provided at the lower end of the leg via a pivot shaft. A swing claw member pivotally mounted so as to be swingable, a screw hole formed in the lower end of the leg portion in a direction orthogonal to the pivot shaft, and a male screw portion screwed into the screw hole, and the male screw And a screw member having a pressing portion that is integrally provided to the portion and that pushes and swings the swing claw member in a direction in which the swing claw advances and retracts.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail with reference to the drawings showing the embodiments.

FIG. 1 shows an embodiment of a tripod for a surveying instrument according to the present invention. This surveying instrument tripod has three legs 1 ...
And a leg head 2 for swingably connecting and holding the upper ends 3 of the three legs 1, and a bubble level 5 having bubbles on the outer surface 4 of the upper ends 3 of the three legs 1. Each is attached (see FIG. 5).

More specifically, as shown in FIGS. 1, 2 and 5, the leg head 2 having a substantially hexagonal disk shape has a central screw hole 6 formed in the vertical direction and an outer surface. At center angle 1
Three recesses 7 ... Are formed at intervals of 20 °. In addition,
At the time of use, the mounting member 24 is screwed into the central screw hole portion 6, and the swing 25 is hung from the mounting member 24.

The leg portion 1 is slidably inserted from the upper end into an outer rod portion 8 having a convex portion 10 which is inserted into the concave portion 7 of the leg head portion 2 and pivotally attached to the outer rod portion 8. In addition, the lower end portion is provided with an inner rod portion 9 having a grounding claw, and is configured to be expandable and contractible. In addition, 11 is a screw for adjusting the slide projection size of the inner rod 9.

The level 5 is a rectangular parallelepiped type made of transparent plastic in which liquid and air bubbles are hermetically contained.
Is attached to the outer surface 4 of the upper end 3 of the outer rod portion 8 in the lateral direction (direction orthogonal to the longitudinal direction of the leg portion 1). In addition, 13 is a level 5
Are the bubbles inside.

Therefore, as shown in FIGS. 1 and 3, at least one of the three legs 1 has a lower end 18 at the lower end 18.
A horizontal adjusting mechanism 14 is provided for finely adjusting the upper surface 12 of the leg head 2 to a horizontal state with high accuracy. The present embodiment exemplifies a case where the horizontal adjusting mechanism 14 is provided on one leg 1.

As shown in FIG. 3A, the horizontal adjusting mechanism 14 has a swinging pawl pivotally attached to a lower end 18 of the inner rod 9 of the leg 1 via a pivot shaft 15. The member 16 and the screw hole 17 formed in the lower end 18 of the inner rod portion 9 of the leg 1 in the direction orthogonal to the pivot shaft 15
And a screw having a male screw portion 19 that is screwed into the screw hole 17 and a pressing portion 20 that is integrally provided on the male screw portion 19 and that pushes and swings the swinging claw member 16 in a direction of screwing forward and backward. Member 21
And are equipped with.

The swinging claw member 16 is the lower end of the inner rod portion 9 of the leg portion 1.
The swing hole 23 has a notch recess 27 into which the screw 18 is inserted, and a swing piece 23 projecting from one opening side of the screw hole 17, and a long hole for inserting the screw member 21 into the swing piece 23. 22 are formed. The pressing portion 20 of the screw member 21 is composed of a pair of hemispherical convex portions 20a and 20b integrally provided on both sides of the elongated hole 22,
The spherical surfaces of the hemispherical projections 20a and 20b are arranged close to the swing piece 23. The elongated hole 22 may be a U-shaped groove.

The horizontal adjusting mechanism 14 thus constructed is
One hemispherical convex portion 20 arranged at the end of the screw member 21.
By rotating b to move it back and forth,
As shown in FIG. 2, the two hemispherical projections 20a and 20b press the rocking piece 23 in the screw advancing / retreating direction, whereby the tip of the rocking claw member 16 is pushed.
16a swings. That is, in the state where the tripod is landed and installed, the pivot shaft 15 swings together with the swing claw member 16 with the tip 16a of the grounded swing claw member 16 as a fulcrum, whereby the pivot shaft 15 side. The inclination of the leg 1 and the other two legs 1, 1 is slightly changed, and the upper surface 12 of the leg head 2 is finely adjusted to be more horizontal (see FIG. 1).

Next, an example of a procedure for installing a tripod for a surveying instrument at a surveying site will be briefly described. As shown in FIGS. 4 and 5, first, the leg 1 (1a) facing the worker 30 is landed on the extension line 31 of the fixed point P. Then, the worker 30 stands between the other two legs 1 (1b) and 1 (1c),
While moving the legs 1b and 1c up and down in the air around a, the plumb bob 25 (weight) at the center of the leg is aligned with the fixed point P, and at the same time, the legs 1a, 1b and 1c The air bubbles 13 of each attached level 5 (see FIG. 2) are guided to the center. And bubbles 13 of each level 5 ...
Since the position where all are centered is the correct height and position of the leg head 2, the two legs 1b, 1c are expanded and contracted while holding the bubbles 13 of each spirit level 5 at the center position. To land. At this time, the bubbles can be easily and reliably visually observed regardless of the opening (inclination) angle of the legs 1a, 1b, 1c.

When the tripod is installed at the fixed point P in this manner, the upper surface 12 of the leg head 2 is in a substantially horizontal state. Then, after the surveying instrument 26 is set on the upper surface 12 side of the leg head 2, the horizontal adjustment mechanism 14 is finely adjusted as described above to bring the upper surface 12 of the leg head 2 closer to the horizontal, and the final perfection is obtained. The horizontal adjustment is performed by adjusting the screw of the surveying instrument. In this way, the preparation for surveying is completed. The procedure for installing the tripod is not limited to this, and a surveying instrument may be first attached to the leg head 2 in some cases.

The present invention is not limited to the above-described embodiment, and for example, the horizontal adjusting mechanism 14 may be provided in each of the two leg portions 1, 1 or the three leg portions 1, ... The upper surface 12 of the leg head 2 can be finely and horizontally adjusted with high accuracy.

[0019]

Since the present invention is configured as described above, it has the following effects.

The level 5 attached to each leg portion 1 (according to claim 1) is capable of visually observing air bubbles inside regardless of whether the leg portion 1 is open (the inclination angle is large or small). The top of the leg head 2 can always be confirmed to be horizontal. In this way, the upper surface 12 of the leg head 2 can be installed in a substantially horizontal shape easily and quickly without requiring skill.

After the tripod is installed (according to claim 2), the swinging claw member 16 of the leveling mechanism 14 is swingably operated to finely adjust the upper surface 12 of the leg head 2 to be closer to horizontal. be able to. Therefore, there is no need for a moving device for horizontal adjustment mounted between the conventional tripod and the surveying instrument, and it can be used at a low cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a tripod for a surveying instrument according to the present invention.

FIG. 2 is an explanatory view showing a spirit level attached to a leg portion.

FIG. 3 is an operation explanatory view showing a horizontal adjustment mechanism.

FIG. 4 is a first explanatory diagram illustrating an installation procedure.

FIG. 5 is a second explanatory diagram illustrating an installation procedure.

[Explanation of symbols]

1 leg 2 leg head 3 upper end 4 outside 5 level 12 Top 14 Leveling mechanism 15 pivot 16 Swing claw member 17 screw holes 18 bottom 19 Male thread 20 Pressing part 21 screw member

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields investigated (Int.Cl. ⁷ , DB name) G01C 15/00-15/14 G03B 17/56 F16M 11/00-11/42

Claims (2)

(57) [Claims] 1. A tripod for a surveying instrument, comprising three legs 1, ... And a leg head 2 which swingably holds upper ends 3 of the three legs 1. On the outer surface 4 of the upper end 3 of the leg portion 1 of the book,
A tripod for a surveying instrument, which is equipped with a level 5 respectively. 2. A horizontal adjustment mechanism 14 for finely adjusting the upper surface 12 of the leg head 2 to a horizontal state, and a lower end 18 of at least one leg portion 1.
The horizontal adjustment mechanism 14 is provided on the leg 1 via a pivot shaft 15.
A swinging pawl member 16 pivotably attached to a lower end 18 of the leg 1, a screw hole 17 formed in the lower end 18 of the leg 1 in a direction orthogonal to the pivot shaft 15, and screwed into the screw hole 17. And a screw member 21 having a male screw portion 19 and a pressing portion 20 that is integrally provided on the male screw portion 19 and that pushes and swings the swing claw member 16 in a screw forward and backward direction. The tripod for a surveying instrument according to claim 1.