JPH0645849Y2 - Thrust clearance adjustment device for surveying instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a thrust clearance adjusting device for a rotary shaft in a surveying instrument, and more particularly to a thrust clearance adjusting device for a rotary shaft used in a telescope such as a level.

[Prior Art] Generally, when leveling work is performed in a surveying instrument, for example, a level, the telescope is rotated horizontally and the target is collimated by looking into the telescope. A rotary shaft for rotating the telescope body is provided integrally with the telescope body. In other words, the rotating shaft is mounted on the barrel, which is connected to the leveling table and is internally provided from the leveling table side into the telescope body. The rotating shaft is configured to rotate in this barrel. For example, FIGS. 2A and 2B show a conventional example, and as shown in these figures, the rotation of the telescope main body 21 includes a barrel 22 provided inside the telescope main body 21 and the barrel. twenty two
It is rotated by a rotating shaft 23 mounted inside. At the lower end of the rotary shaft 23, a small-diameter convex screw-engaging portion 23 directed downward.
a is formed, and the rotary shaft 23 is pulled out from the shaft cylinder 22 from above by screwing the press nut 24 into this convex screwing portion 23a or by locking a fixing ring (not shown). Was prevented. And in the case of such a configuration, always between the upper end surface 24a of the press nut 24 and the lower end surface 22a of the barrel 22,
It is required to form a constant gap to ensure rotation. That is, if the upper end surface 24a of the press nut 24 or the like and the lower end surface 22a of the shaft cylinder 22 come into firm contact with each other, the rotary shaft 23 is fixed by the shaft cylinder 22 and the press nut 24 when the telescope body 21 is rotated. It will be rotated and cannot be rotated. Therefore, in order to prevent such inconvenience, the rotary shaft 23 is processed to be slightly longer than the shaft cylinder 22, and the lower end shoulder surface 23b of the rotary shaft 23 is projected from the shaft cylinder 22 to form a gap. Was there.

[Problems to be Solved by the Invention] As described above, according to the conventional technique, the lower end shoulder surface 23 of the rotary shaft 23 is
It is necessary to process and form a little longer than the shaft cylinder 22 so that b is projected from the shaft cylinder 22. However, in a precision machine such as a surveying instrument, the allowable range of machining error is extremely small, and if the length of the rotary shaft 23 is too long, the gap between the presser nut 24 and the barrel 22 becomes too large. Although it is possible to prevent the rotary shaft 23 from coming off from above,
The gap causes looseness between the holding nut 24 and the telescope body 21.

Further, as shown in FIG. 2B, when the rotary shaft 23 is machined shorter than the shaft cylinder 22 and the lower end shoulder surface 23b does not project from the shaft cylinder 22, the upper end surface of the presser nut 24 'or the like is machined. hand,
The clearance between the barrel 22 and the press nut 24 'must be adjusted. Thus, in the thrust gap adjusting device for the rotary shaft using the conventional press nut 24 or the like, according to the processing state of the shaft cylinder and the rotary shaft, the related members are individually selected and processed, for example, the press nut and the like. There is a problem that the telescope is rotated smoothly, processing precision of the rotating shaft and the like is strictly required, and workability is poor.

The object of the present invention is that the workability is good without being affected by the processing accuracy of the rotating shafts and the like that make up the thrust clearance adjusting device of the surveying instrument.
Another object of the present invention is to provide a thrust clearance adjusting device for a surveying instrument that can prevent the rotation shaft of the surveying instrument from slipping off and maintain smooth rotation.

[Means for Solving the Problems] The present invention has been made to solve the above problems, and a thrust gap adjusting device of a surveying instrument according to the present invention is provided integrally with a telescope and has a threaded portion at its end. A rotation axis having
The press nut includes a shaft cylinder in which the rotary shaft is rotatably mounted on a leveling table, a press nut screwed into a screwing portion of the rotary shaft, and a press screw screwed into the press nut. A recess having a diameter substantially the same as that of the rotating shaft is formed on the upper surface, and a screwing recess that engages with a screwing portion of the rotating shaft is formed in the recess and a screwing hole that is continuous with the screwing recess. Is provided, and the pressing screw is screwed into the screw hole to press the rotating body.

Further, it is preferable to interpose a pressing piece between the rotary shaft and the pressing screw.

[Operation] According to the thrust clearance adjusting device of a surveying instrument of the present invention, when the rotary shaft provided integrally with the telescope is pressed by the press nut, the recess formed on the upper surface of the press nut has a diameter substantially the same as that of the rotary shaft. Thus, the rotary shaft can be housed, and the threaded recessed portion that engages with the threaded portion of the rotary shaft is formed in the recessed portion. The gap caused by the variation can be made constant by the press nut. At this time, a screw hole continuous with the screw recess is bored, and a cap screw is screwed into this screw hole to press the rotating body. Since the screw is held at two places, the press nut can be securely fixed to the rotating body.

In addition, by inserting a presser piece between the rotary shaft and the presser screw, pressurizing force is applied to the presser nut and the convex screwing part, and the gap between the shaft cylinder and the presser nut is maintained and the presser nut is securely fixed. You can

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. The members and the like described below are not intended to limit the present invention and can be variously modified within the scope of the present invention.

1A to 1C show one embodiment of the present invention, and the thrust gap adjusting device S of this embodiment shows an example used for the rotary shaft of a telescope of the level as a surveying instrument. . As shown in FIG. 1A, the thrust clearance adjusting device S of this example includes a cylindrical barrel 2, a rotary shaft 3 rotatably mounted in the barrel 2, a holding nut 4, and a holding piece. 5 and a cap screw 6.

The shaft cylinder 2 of this example is installed inside a level main body 1 as a surveying instrument, and the shaft cylinder 2 is configured so that a rotary shaft 3 formed integrally with a telescope as a rotary side main body is rotatable. It is attached to the leveling table. Therefore, the telescope rotates with respect to the leveling table via the rotating shaft 3. This rotating shaft 3 has an upper surface (first A
An engaging portion 3c having a diameter larger than the inner diameter of the barrel 2 is formed in the drawing), and the rotating shaft 3 is engaged with the barrel 2 at the upper end by the engaging portion 3c. A convex threaded portion 3a is formed at the end of the rotary shaft 3 opposite to the engaging portion 3c. A male screw is threaded on the convex screwing portion 3a,
The convex screwing portion 3a and the pressing nut 4 described below are screwed together with the screwing portion
It is screwed in.

The holding nut 4 of this example has a cylindrical shape, and the upper surface 4a is
A recess having a diameter slightly larger than the inner diameter α of the rotating shaft 3
4b is formed, in the center of the recessed portion 4b, a screwing recessed portion 4c in which a male screw to be screwed with the convex screwed portion 3a is threaded is provided, and is continuous with the screwed recessed portion 4c. A screwing hole 7 for screwing with a cap screw 6 described later is formed.

A pressing piece 5 is arranged between the convex screwing portion 3a in the screwing concave portion 4c and the screwing hole 7, and the pressing piece 5 of this example has a disk-like shape whose front and back surfaces are flat. is doing. The pressing piece 5 is arranged so as to press the rotary shaft 3 with the pressing screw 6 screwed into the screw hole 7. By using the pressing piece 5 as in this example, the convex screwing portion 3a and the pressing nut 4 are securely fixed by applying the pressing force of the rotary shaft 3 by the pressing screw 6.
Note that reference numeral 9 indicates a threaded portion between the threaded hole 7 and the cap screw 6,
Reference numeral 10 indicates a leveling screw.

Next, the operation of the thrust gap adjusting device S having the above configuration will be described together with the processing state of the barrel and the rotary shaft.

FIG. 1A shows a state in which the lower end shoulder surface 3b of the rotary shaft 3 is machined so as to slightly project from the barrel 2. In the case of this example, the presser nut 4 is coupled to the rotary shaft 3 by screwing a screwing recess 4c and a convex screwing portion 3a protruding from the lower end of the rotary shaft 3 into each other. At this time, the holding nut 4 can be rotated to form a certain small gap between the barrel 2 and the upper surface 4a of the holding nut 4. Then, after forming the gap, the holding screw 6 is screwed from below the screwing hole 7 of the holding nut 4, and the holding piece 5 is interposed between the holding screw 6 and the rotating shaft 3 to rotate the rotary shaft. Press 3. This way,
The convex threaded portion 3a and the presser nut 4 can be securely fixed, and the presser piece 5 is interposed so that the gap between the shaft cylinder and the presser nut can be easily adjusted.

FIG. 1B shows the case where the rotary shaft 3 is processed to be slightly longer than the shaft cylinder 2. At this time, the lower end shoulder surface 3b of the rotating shaft 3 which has been machined longer is housed in the recess 4b formed in the upper surface 4a of the press nut 4, and the space between the shaft cylinder 2 and the upper surface 4a of the press nut 4 is set. The gap can be made constant by rotating the holding nut 4 and adjusting its position, as in the case of FIG. 1A.

FIG. 1C shows the case where the rotary shaft 3 is processed short. That is, the convex threaded portion 3 does not project sufficiently downward from the shaft tube 2, but the threaded portion 8 between the threaded concave portion 4c of the presser nut 4 and the convex threaded portion 3a is adjusted. Thus, a constant gap can be provided between the shaft tube 2 and the upper surface 4a of the press nut 4. At this time, the holding nut 4 is stably fixed by screwing the holding screw 6 from below the holding nut 4 and pressing the rotating shaft 3 via the holding piece 5.

In the above embodiment, an example in which the thrust gap in the vertical rotation shaft is adjusted has been shown, but it goes without saying that it can also be applied to the horizontal shaft.

[Advantage of Invention] According to the thrust clearance adjusting device for a surveying instrument of the present invention, even if there is some variation in the length dimension of the rotating shaft as described above, the clearance between the presser nut and the shaft cylinder is Since it can be kept constant at all times, the rotation shaft of the surveying instrument can be prevented from coming off, and smooth rotation can always be maintained without play. Further, even if there is some variation in length and the like between the shaft cylinder and the rotating shaft, the thrust clearance can be adjusted, so that the manufacturing accuracy of the rotating shaft is not affected and the yield is good. Good workability. Furthermore, since the thrust clearance can be freely adjusted, replacement and repair work of related parts such as the rotary shaft can be reduced. In addition, the convex threaded portion and the presser nut can be securely fixed, and by interposing the presser piece, the gap between the shaft cylinder and the presser nut can be easily adjusted.

[Brief description of drawings]

1A to 1C show an embodiment of the present invention. FIG. 1A is a sectional view of a main part showing a state in which a rotary shaft is slightly protruded from a barrel, and FIG. 1B is a rotary barrel. 1C is a cross-sectional view of a main part showing a state in which the rotary shaft is shorter than the barrel, and FIGS. 2A and 2B are cross-sectional views of the main part showing a conventional example. is there. 1 ... Telescope main body, 2 ... Shaft cylinder, 3 ... Rotating shaft, 3a ... Convex threaded portion, 3b ... Bottom shoulder surface, 4 ... Press nut, 4a ... Press nut upper surface, 4b ... Concave surface, 4c ... Screw recess, 5 ... Presser piece 6 ... Presser screw, S ... Thrust clearance adjusting device for surveying instrument.

Claims (2)

[Scope of utility model registration request] 1. A rotary shaft provided integrally with a telescope and having a threaded portion at its end, a barrel having a rotary shaft rotatably mounted on a leveling table, and a screwed portion of the rotary shaft. A press nut to be fitted and a press screw to be screwed with the press nut,
A recess having a diameter substantially the same as that of the rotating shaft is formed on the upper surface of the press nut, and a screwing recess that engages with a screwing portion of the rotating shaft is provided in the recess and is continuous with the screwing recess. A thrust clearance adjusting device for a surveying instrument, wherein a screwing hole is provided, and the cap screw is screwed into the screwing hole to press the rotating body. 2. The thrust clearance adjusting device for a surveying instrument according to claim 1, wherein a pressing piece is interposed between said rotary shaft and said pressing screw.