CN210652451U

CN210652451U - Precise long-rod compasses

Info

Publication number: CN210652451U
Application number: CN201921006857.9U
Authority: CN
Inventors: 关高文; 翟梓曦
Original assignee: GUANGDONG LIGHT INDUSTRY SENIOR TECHNICIAN SCHOOL
Current assignee: GUANGDONG LIGHT INDUSTRY SENIOR TECHNICIAN SCHOOL
Priority date: 2019-06-28
Filing date: 2019-06-28
Publication date: 2020-06-02
Anticipated expiration: 2029-06-28

Abstract

The utility model discloses an accurate stock compasses, including long chi, first movable slider and second movable slider, be equipped with the scale mark on the long chi, first movable slider and second movable slider all set up to slide to the long chi; the first movable sliding block is provided with a first locking device, and when the first locking device is locked, the first movable sliding block is fixed relative to the long ruler; the second movable sliding block is provided with a second locking device, and when the second locking device is locked, the second movable sliding block is fixed relative to the long ruler; the first movable sliding block is provided with a centering needle, the second movable sliding block is provided with a drawing tool, and the centering needle and the drawing tool are parallel to the scale lines. The utility model discloses distance between the centering needle of accurate stock compasses and the drawing tool equals the distance that marks on the scale mark, and the distance can be greater than 1m, and the cooperation is nimble between each subassembly, simple to operate, and applicable occasion is extensive.

Description

Precise long-rod compasses

Technical Field

The utility model relates to a teaching tool field especially relates to an accurate stock compasses.

Background

Mathematics plays irreplaceable role in human historical development and social life, in the course of contemporary students, mathematics is also a course which must be repaired, along with the continuous development of economy, the living standard of people is continuously improved, people pay more and more attention to the education cause, the demand of learning equipment is continuously increased, take geometric drawing board for high school mathematics as an example, the geometric drawing board for high school mathematics students at present has different styles, wherein the geometric drawing board comprises compasses which are commonly used for drawing circles and making marking lines, but a plurality of problems exist to influence the use.

At present, compasses on the market have teaching or learning tools, can draw a circular arc radius not more than 50 centimeters, and have a small size range. The other compasses tool is used in woodworking, glass and building industries, the radius of a drawn arc often exceeds 1 meter, but the problems of inaccurate scale positioning, easy change, inaccurate arc drawing numerical value, complex numerical value adjustment, inflexibility and the like exist.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, the utility model aims to provide a novel accurate stock compasses to overcome the radius that draws circle or circular arc that current compasses exist short, the scale location is not accurate, produce the change easily, draw circular arc numerical value inaccuracy, adjustment numerical value loaded down with trivial details, inflexible scheduling problem.

The purpose of the utility model is realized by adopting the following technical scheme:

a precise long-rod compasses comprises a long ruler, a first movable sliding block and a second movable sliding block, wherein the long ruler is provided with scale marks, and the first movable sliding block and the second movable sliding block are both arranged to slide relative to the long ruler;

the first movable sliding block is provided with a first locking device, and when the first locking device is locked, the first movable sliding block is fixed relative to the long ruler; the second movable sliding block is provided with a second locking device, and when the second locking device is locked, the second movable sliding block is fixed relative to the long ruler;

the first movable sliding block is provided with a centering needle, the second movable sliding block is provided with a drawing tool, and the centering needle and the drawing tool are parallel to the scale lines.

Furthermore, the first movable sliding block comprises a first sleeving groove, two ends of the first sleeving groove are respectively provided with a first holding clamp, the second movable sliding block comprises a second sleeving groove, and two ends of the second sleeving groove are respectively provided with a second holding clamp;

the first sleeving groove and the second sleeving groove are sleeved with the long ruler, and the first holding clamp and the second holding clamp are abutted to one surface of the long ruler, which is provided with scale marks.

Furthermore, a first through hole and a first positioning hole which are perpendicular to each other are arranged on the first movable sliding block, and the first positioning hole extends to the first through hole;

during assembly, the centering needle penetrates through the first through hole, and the first positioning screw penetrates through the first positioning hole and abuts against the centering needle.

Furthermore, a second through hole and a second positioning hole which are perpendicular to each other are formed in the second movable sliding block, and the second positioning hole extends to the second through hole;

during assembly, the drawing tool penetrates through the second through hole, and the second positioning screw penetrates through the second positioning hole and abuts against the drawing tool.

Furthermore, the first locking device comprises a first locking screw and a first locking hole arranged on the first movable sliding block, and the second locking device comprises a second locking screw and a second locking hole arranged on the second movable sliding block;

during the equipment, first locking screw passes first locking hole and butt long chi, and second locking screw passes second locking hole and butt long chi.

The first clamping grooves are formed between the two ends of the first sleeving groove and the first holding clamp, and the second clamping grooves are formed between the two ends of the second sleeving groove and the second holding clamp;

during the equipment, first transparent plate embedding first joint groove, second transparent plate embedding second joint groove, first transparent plate and first cover connect the recess to enclose the length chi, and the second transparent plate and second cover connect the recess to enclose the length chi.

Furthermore, a pair of first balance holes are formed in the top of the first movable sliding block, the first balance holes extend to the first transparent plate, a pair of second balance holes are formed in the top of the second movable sliding block, and the second balance holes extend to the second transparent plate;

during assembly, one pair of balance screws respectively penetrate through the pair of first balance holes to abut against the first transparent plate, and the other pair of balance screws respectively penetrate through the pair of second balance holes to abut against the second transparent plate.

Further, all be marked with the location fine rule on first transparent plate and the second transparent plate, the location fine rule is parallel with the scale mark, and the location fine rule on the first transparent plate and the axis parallel and level of centering needle, location fine rule on the second transparent plate and drawing tool's axis parallel and level.

Further, the long ruler comprises a long rod and a graduated scale, the graduated scale is arranged along the long axis direction of the long rod, and the graduated scale is attached to the long rod.

Furthermore, the long rod is a square tube, two ends of the square tube are provided with ruler end plugs, and each ruler end plug comprises a plug seat and a plug head arranged on the plug seat;

the plug head is inserted into the square pipe, and on the cross section of the square pipe, the plug seat extends out of the cross section of the square pipe.

Compared with the prior art, the beneficial effects of the utility model reside in that:

the utility model discloses accurate stock compasses includes long chi, first activity slider and second activity slider, is equipped with the scale mark on the long chi, and first activity slider and second activity slider all set to the relative long chi and slide, from this through the distance between the first activity slider of scale mark accurate determination on the long chi and the second activity slider. Be equipped with first locking device on the first movable sliding block, when first locking device locked, first movable sliding block was fixed relatively long chi, from this fixes first movable sliding block on long chi through first locking device. And a second locking device is arranged on the second movable sliding block, and when the second locking device is locked, the second movable sliding block is fixed relative to the long ruler, so that the second movable sliding block is fixed on the long ruler through the second locking device. The first movable sliding block is provided with a centering needle, the second movable sliding block is provided with a drawing tool, and the centering needle and the drawing tool are parallel to the scale marks. After setting for the distance between first activity slider and the second activity slider, fix first activity slider and second activity slider through first locking device and second locking device, prevent not hard up of centering needle and drawing tool, in addition, centering needle and drawing tool parallel arrangement ensure that the distance between centering needle and the drawing tool strictly equals the distance that marks on the scale mark, and the distance can be greater than 1m, in addition, the cooperation is nimble between each subassembly, simple to operate, and application scenario is extensive.

Drawings

FIG. 1 is a schematic structural view of a precise long rod compass according to an embodiment of the present invention;

FIG. 2 is an enlarged view of a portion of the precision long rod compass of FIG. 1;

FIG. 3 is an enlarged view of a portion of the precision long rod compass of FIG. 1;

FIG. 4 is a schematic structural diagram of a first movable slider;

FIG. 5 is a schematic structural view of a second movable slider;

FIG. 6 is an exploded view of a first movable slider;

fig. 7 is a schematic view of a ruler end plug.

In the figure: 1. a long ruler; 11. a long rod; 12. a graduated scale; 2. a first movable slider; 21. a first locking device; 211. a first locking screw; 212. a first locking hole; 22. a centering pin; 23. a first nesting groove; 24. a first holding clamp; 25. a first through hole; 26. a first positioning hole; 27. a first clamping groove; 28. a first balance hole; 3. a second movable slider; 31. a second locking device; 32. a drawing tool; 33. a second sleeving connection groove; 34. a second holding clamp; 4. a first set screw; 5. a first transparent plate; 61. a plug seat; 62. a plug head.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that the embodiments or technical features described below can be arbitrarily combined to form a new embodiment without conflict.

Example 1

As shown in fig. 1, the present invention is a pair of precision long rod compasses. The precise long-rod compasses comprise a long ruler 1, a first movable sliding block 2 and a second movable sliding block 3, wherein the first movable sliding block 2 and the second movable sliding block 3 are respectively sleeved with the long ruler 1, namely, the first movable sliding block 2 and the second movable sliding block 3 both use the long ruler 1 as a sliding rail and slide left and right (corresponding to the up-down sliding in figure 1) relative to the long ruler 1. In addition, the long ruler 1 is provided with scale marks (standard scale marks, for example, scale marks with a precision of 1mm or 5 mm), and when the first movable slider 2 and the second movable slider 3 slide left and right relative to the long ruler 1, the horizontal distance between the first movable slider 2 and the second movable slider 3 can be measured by means of the long ruler 1, so that the radius of a circle drawn by the precision long-rod compass can be planned.

As shown in fig. 2-3, the first movable sliding block 2 is further provided with a first locking device 21, and when the first locking device 21 is locked, the first movable sliding block 2 is fixed relative to the long ruler 1; similarly, the second movable sliding block 3 is provided with a second locking device 31, and when the second locking device 31 is locked, the second movable sliding block 3 is fixed relative to the long ruler 1. Therefore, the first movable sliding block 2 is fixed at the fixed position of the long ruler 1 through the first locking device 21, the second movable sliding block 3 is fixed at the fixed position of the long ruler 1 through the second locking device 31, the distance between the first movable sliding block 2 and the second movable sliding block 3 is controlled when drawing is convenient, and drawing of circles or arcs with fixed radiuses is guaranteed. The first movable sliding block 2 is further provided with a centering needle 22, correspondingly, the second movable sliding block 3 is provided with a drawing tool 32, wherein the centering needle 22 and the drawing tool 32 are both parallel to the scale lines. During drawing, slide first movable slide block 2 and second movable slide block 3, measure the distance between first movable slide block 2 and the second movable slide block 3 through the scale mark on the long chi 1, rethread first locking device 21 is fixed first movable slide block 2, fix second movable slide block 3 through second locking device 31, centering needle 22 and drawing tool 32 are all parallel with the scale mark, and the distance between centering needle 22 and drawing tool 32 is fixed down. At this time, the centering pin 22 is fixed at a point of the drawing position, and the long ruler 1 is rotated around the centering pin 22 to perform a circle drawing process of the drawing tool 32. This accurate stock compasses have the circular arc radius not restricted relatively for traditional compasses (1 ~ 5m can be set to the length of long chi promptly and do not influence the use), and centering pin 22 is accurate fixed with drawing tool 32, draws the circle in-process and is difficult to not hard up, and the circular arc rule of drawing uses also more nimble, convenient.

In this embodiment, the centering pin 22 is preferably a metal tube with a steel pin at one end and the drawing instrument 32 is preferably a conventional cylindrical pencil. The positioning pin 22 can fix the drawing position well, and the pencil can be replaced at will and automatically drawn out, thereby facilitating drawing.

In this embodiment, the centering pin 22 is detachably connected with the first movable sliding block 2, correspondingly, the drawing tool 32 is detachably connected with the second movable sliding block 3, so that the user can conveniently install and use the precise long-rod compass, the head of the centering pin 22 and the distance between the head of the drawing tool 32 and the long rod 1 can be adjusted according to the field conditions in use, and the application range is wide. In other embodiments, the centering pin 22 may also be fixedly connected to the first movable slider 2, and the drawing tool 32 may also be fixedly connected to the second movable slider 3, only by ensuring that the connection line between the head of the centering pin 22 and the head of the drawing tool 32 is parallel to the long ruler 1, so that it can be ensured that the radius of the drawn circle or arc is strictly equal to the distance displayed on the long ruler 1.

As a preferred embodiment, as shown in fig. 4-5, the first movable sliding block 2 is provided with a first engaging groove 23, that is, the first movable sliding block 2 is shaped like a Chinese character 'ao', and a groove formed in the middle of the first movable sliding block 2 shaped like a Chinese character 'ao' is the first engaging groove 23. Two ends of first muffjoint recess 23 all are equipped with first armful pincers 24, and first muffjoint recess 23 is used for cup jointing the back (the one side that is not equipped with the scale mark) of long chi 1, and first armful pincers 24 detains the front (the one side that is equipped with the scale mark) of long chi 1 from the top and bottom of long chi 1, play supplementary first activity slider 2 and cup joint long chi 1's effect, prevent that first activity slider 2 from derailing. In a similar way, the second movable sliding block 3 is provided with a second sleeving groove 33, two ends of the second sleeving groove 33 are respectively provided with a second holding clamp 34, the second sleeving groove 33 is used for sleeving the long ruler 1, the second holding clamp 34 clamps the long ruler 1 from the upper side and the lower side of the long ruler 1, the effect of assisting the second movable sliding block 3 in sleeving the long ruler 1 is achieved, and derailment of the second movable sliding block 3 is prevented.

In the present embodiment, the first holding clamp 24 and the second holding clamp 34 both abut against a surface of the long ruler 1 provided with the scale marks, in other embodiments, the first holding clamp 24 and the second holding clamp 34 may abut against a surface of the long ruler 1 opposite to the scale marks, or the first movable slider 2 and the second movable slider 3 may be opposite to the direction in which the long ruler 1 is sleeved (i.e. the first holding clamp 24 and the second holding clamp 34 are opposite to the surface of the long ruler 1 abutting against).

In the present embodiment, the two ends of the first engaging groove 23 are both provided with the first clasping clamp 24, in other embodiments, one end of the first engaging groove 23 is provided with the first clasping clamp 24, and the first clasping clamp 24 abuts against the long ruler 1, so that the first movable slider 2 is also prevented from derailing. Similarly, the second movable sliding block 3 may also be provided with only the second clasping clamp 34.

As a preferred embodiment, as shown in fig. 6, the second movable slider 3 has the same shape and structure as the first movable slider 2, and the difference is only: the first movable slide block 2 is inserted with a centering needle 22, and the second movable slide block 3 is inserted with a drawing tool 32. The following describes the structure of the first movable slider 2 and the second movable slider 3 in detail, taking the first movable slider 2 as an example. The first movable slider 2 is provided with a first through hole 25 and a first positioning hole 26, the first through hole 25 and the first positioning hole 26 are perpendicular to each other, and the first positioning hole 26 extends to the first through hole 25. When the first movable slider 2 is assembled and used, the centering pin 22 is firstly inserted through the first through hole 25, the centering pin 22 is adjusted to a proper position, then the first positioning screw 4 is inserted through the first positioning hole 26, the first positioning screw 4 is screwed until the head of the first positioning screw 4 abuts against the centering pin 22, and the centering pin 22 is fixed. When the centering pin 22 needs to be adjusted to the position again, the first positioning screw 4 can be loosened, and the adjustment process of the centering pin 22 is facilitated. The same method is used for the second movable slider 3 to hold the drawing tool 32.

In this embodiment, the outer walls of the centering pin 22 and the drawing tool 32 may further be provided with a plurality of positioning holes or positioning grooves, for example, a positioning groove is provided at a distance of 5cm from the head of the centering pin 22, a positioning groove is provided at a distance of 10cm from the head of the centering pin 22, a positioning groove is provided at a distance of 15cm from the head of the centering pin 22, and a positioning groove is provided at a distance of 20cm from the head of the centering pin 22, and similarly, a positioning groove may be provided at a distance of 5cm from the head of the drawing tool 32, a positioning groove is provided at a distance of 10cm from the head of the drawing tool 32, a positioning groove is provided at a distance of 15cm from the head of the drawing tool 32, and a positioning groove is provided at a distance of 20cm from the head of the drawing tool 32, and when in use, the heads of the first positioning screws 4 are respectively inserted into the corresponding positioning grooves, thereby ensuring that a connection line, it is also possible to ensure accurate control of the distance between the head of the centering pin 22 and the head of the drawing tool 32 and the long ruler 1.

As a preferred embodiment, as shown in fig. 6, the first locking device 21 includes a first locking screw 211 and a first locking hole 212 provided on the first movable slider 2, wherein the first locking hole 212 extends from the top of the first movable slider 2 to the first sleeving groove 23. When this first movable slider 2 is used in the equipment, cup joint long chi 1 through its first cup joint recess 23 with first movable slider 2 earlier, slide first movable slider 2 to suitable position after, pass first locking hole 212 with butt long chi 1 with first locking screw 211 again, from this fix first movable slider 2 in the suitable position of long chi 1 through first locking device 21. The second movable slider 3 also fixes the second movable slider 3 in place on the long ruler 1 by the second locking means 31.

In this embodiment, a gasket, for example, a common silicone gasket, may be further installed in the first positioning hole 26, and when the first positioning screw 4 is inserted into the first positioning hole 26 to abut against the centering pin 22, the gasket is disposed between the first positioning screw 4 and the centering pin 22, so that the centering pin 22 can be fixed well by virtue of the elastic effect of the gasket, and the centering pin 22 is prevented from being loosened relative to the first positioning screw 4. Similarly, a washer is also installed in the first locking hole 212, and the first locking screw 211 abuts against the long ruler 1 by abutting against the washer, and also has a good function of fixing the long ruler 1.

As a preferred embodiment, as shown in fig. 6, the first transparent plate 5 covering the scale marks is further included, accordingly, first clamping grooves 27 are formed between both ends (U-shaped ends in the drawing) of the first engaging groove 23 and the upper and lower first claspers 24, and a pair of the first clamping grooves 27 clamp the first transparent plate 5 from the upper and lower ends, thereby performing the function of fixedly mounting the first transparent plate 5. In this embodiment, the first transparent board 5 is arranged in a shape like a Chinese character 'tu', two ends of the first transparent board 5 in the shape like a Chinese character 'tu' are respectively clamped into the first clamping grooves 27, and the middle part of the first transparent board 5 in the shape like a Chinese character 'tu' is flush with the first holding clamp 24, so that the flatness of the surface of the first movable slider 2 is ensured, and the experience of the use of the first movable slider is improved. The first transparent plate 5 covers the scale marks below the first transparent plate, and a user can read the position of the first movable slider 2 (i.e. the position of the centering pin 22) through the first transparent plate 5. Meanwhile, a second transparent plate (not shown) is also provided on the second movable slider 3, and functions the same as the first transparent plate 5.

In a preferred embodiment, the top of the first movable slider 2 is further provided with a pair of first balance holes 28, and the first balance holes 28 extend from the top of the first movable slider 2 to the first transparent plate 5. When the assembly is used, a pair of balance screws respectively penetrate through the pair of first balance holes 28 to abut against the first transparent plate 5, and the pair of balance screws respectively abut against two sides of the first transparent plate 5, so that the first transparent plate 5 is fixed. In other embodiments, only one first balancing hole 28 and balancing screw may be provided, and the balancing screw may abut against the middle position of the first transparent board 5, and may also have the function of fixing the first transparent board 5. Similarly, the top of the second movable slider 3 is also provided with a second balance hole through which a balance screw passes to abut against the second transparent plate.

In a preferred embodiment, the first transparent plate 5 and the second transparent plate are marked with positioning thin lines, the positioning thin lines are parallel to the scale marks (both in the vertical direction), the positioning thin lines on the first transparent plate 5 are flush with the central axis of the centering pins 22, and the positioning points of the centering pins 22 are located on the central axis of the centering pins 22, so that the positioning thin lines on the first transparent plate 5 correspond to the positioning points of the centering pins 22, and the positioning points of the centering pins 22 are determined by the positioning thin lines. Similarly, the positioning thin lines on the second transparent plate are flush with the central axis of the drawing tool 32, and the position of the pen point of the drawing tool 32 is also determined by the positioning thin lines on the second transparent plate. The distance between the centering pin 22 and the drawing tool 32 can be determined by the distance between the positioning thin lines on the first transparent plate 5 and the positioning thin lines on the second transparent plate.

In a preferred embodiment, the first transparent plate 5 and the second transparent plate are both transparent acrylic plates, and the transparent acrylic plates are colored with green pigment by cutting fine lines, so that the difference between the positioning fine lines and the scale marks on the long ruler 1 can be highlighted, and the centering pin 22 and the drawing tool 32 can be accurately positioned.

Example 2

Example 2 differs from example 1 only in that: long chi 1 in embodiment 2 includes stock 11 and scale 12, and scale 12 sets up along 11 major axis directions of stock, and scale 12 closely laminates with stock 11.

As preferred embodiment, as shown in FIG. 2, the long rod 11 adopts the hollow square aluminum alloy tube as the compass long rod, the whole weight is controlled under the condition of ensuring the stability, and the hollow square aluminum alloy tube can also splice a plurality of hollow square aluminum alloy tubes through the built-in bolt so as to realize the extension of the compass long rod. The graduated scale 12 uses an I-grade precision measuring tape as a graduated scale on the compasses, so that the precision of the graduated scale 12 can be ensured, and the graduated scale 12 can be tightly attached to the long rod 11. Many hollow square pipes of aluminum alloy can also splice through embedded socket joint spare (for example bolt) to the length of extension stock 11 is with the demand that satisfies the drawing of major radius circular arc.

In a preferred embodiment, the two ends of the square pipe are provided with a ruler end plug, and the ruler end plug comprises a plug seat 61 and a plug head 62 arranged on the plug seat 61. When in use, two ruler end plugs are respectively plugged into the left end and the right end of the long ruler 1, namely, the square pipe is inserted through the plug 62. In this embodiment, the bottom area of the plug seat 61 is larger than the cross-sectional area of the square tube, that is, the plug seat 61 blocks the square tube from the left and right ends, and the first movable slider 2 and the second movable slider 3 are prevented from slipping off the long ruler 1. In other embodiments, it is sufficient to ensure that the plug seat 62 has a portion that extends beyond the cross-section of the square tube, in the cross-section of the square tube.

the utility model discloses the radius scope of circle or circular arc can be adjusted in a flexible way as required to accurate stock compasses, and 1 scope of long ruler can install the extension rod additional according to the user's demand, draws the circular arc radius and surpasses 5 meters all can the I level in circular arc size precision steel tape measure industry standard QB/T2443-2011: (0.1+0.1L) mm.

Description of the operation:

firstly, a first movable slide block 2 and a second movable slide block 3 are installed according to the attached drawing 1, the distance between the first movable slide block 2 and the second movable slide block 3 is adjusted, and the first movable slide block 2 and the second movable slide block 3 are respectively fixed at the fixed positions of the long ruler 1 through a first locking device 21 and a second locking device 31.

Secondly, the first positioning screw 4 is loosened, the centering pin 22 is installed, the first positioning screw 4 is locked, and the centering pin 22 is fixed.

Thirdly, the second positioning screw is loosened, the pencil is installed, and the second positioning screw is locked, so that the distance from the head of the pencil to the long ruler 1 is equal to the distance from the head of the centering pin 22 to the long ruler 1.

Fourthly, the compasses are taken up, the center of the circular arc is firstly determined by the centering needle 22, the left centering needle 22 is pressed by the left hand, and the pencil is rotated by the right hand to draw the circular arc or the circle.

The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention cannot be limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are all within the protection scope of the present invention.

Claims

1. A precise long-rod compasses is characterized by comprising a long ruler, a first movable sliding block and a second movable sliding block, wherein scale marks are arranged on the long ruler, and the first movable sliding block and the second movable sliding block are arranged to slide relative to the long ruler;

2. The precise long-bar compass according to claim 1, wherein the first movable sliding block comprises a first sleeving groove, the two ends of the first sleeving groove are provided with first holding clamps, the second movable sliding block comprises a second sleeving groove, and the two ends of the second sleeving groove are provided with second holding clamps;

3. The precision long-bar compass according to claim 2, wherein the first movable slide block is provided with a first through hole and a first positioning hole which are perpendicular to each other, and the first positioning hole extends to the first through hole;

4. The precision long-bar compass according to claim 2, wherein the second movable slide block is provided with a second through hole and a second positioning hole which are perpendicular to each other, and the second positioning hole extends to the second through hole;

5. The precision long-bar compass of claim 2, wherein the first locking device comprises a first locking screw and a first locking hole provided on the first movable slide block, and the second locking device comprises a second locking screw and a second locking hole provided on the second movable slide block;

6. The precise long-bar compass according to claim 2, further comprising a first transparent plate and a second transparent plate covering the scale marks, wherein a first clamping groove is formed between each of two ends of the first sleeving groove and the first holding clamp, and a second clamping groove is formed between each of two ends of the second sleeving groove and the second holding clamp;

7. The precision long-bar compass according to claim 6, wherein the first movable slide block has a pair of first balance holes at the top thereof, the first balance holes extending to the first transparent plate, and the second movable slide block has a pair of second balance holes at the top thereof, the second balance holes extending to the second transparent plate;

8. The precision long-rod compass according to claim 7, wherein the first transparent plate and the second transparent plate are marked with positioning fine lines, the positioning fine lines are parallel to the scale marks, the positioning fine lines on the first transparent plate are flush with the central axis of the centering pin, and the positioning fine lines on the second transparent plate are flush with the central axis of the drawing tool.

9. The precision long-rod compass of claim 2, wherein the long rod comprises a long rod and a graduated scale, the graduated scale is arranged along the long axis of the long rod, and the graduated scale is attached to the long rod.

10. The precision long-bar compass of claim 9, wherein the long bar is a square tube, and both ends of the square tube are provided with ruler end plugs, and each ruler end plug comprises a plug seat and a plug head arranged on the plug seat;