Ranging equipment for forestry investigation

Abstract

The utility model relates to the field of distance measuring equipment, in particular to distance measuring equipment for forestry investigation, which comprises a bottom plate. A guide rod is fixedly connected to the upper end of the bottom plate, a first measuring block sleeves the side wall of the guide rod, a moving mechanism is arranged at the lower end of the bottom plate, and a first groove penetrates through the upper end of the first measuring block. According to the utility model, the second measuring block is pulled out, the limiting block slides along the groove of the first groove body, the extension length is rapidly read through the first scale line groove and the second scale line groove, the rotating block is matched to rotate around the second fixing column by a proper angle, and the second electric cylinder accurately inserts the output shaft into the positioning hole, so that the rotating block is parallel to the first measuring block; and finally, reference positioning in the horizontal direction is achieved through the measuring rod in the fixing cylinder, the next planting point position can be rapidly determined conveniently, and the problem that in the prior art, equal-distance rapid distance measurement is difficult to conduct on the point positions needing planting on the land in the forest farm at different heights, and consequently the point position uniformity is not high is solved.

Description

Technical Field

[0001] The utility model belongs to the field of ranging devices, and particularly relates to a ranging device for forestry surveying and mapping. Background Technique

[0002] Forestry surveying and mapping is an important basic work for forest resource management, ecological protection and forestry project planning. One of its core tasks is to accurately measure the terrain, vegetation distribution, tree parameters, etc. in the forest area. In traditional forestry surveying and mapping, the accuracy and efficiency of ranging devices directly affect the quality and cost of data collection.

[0003] At present, the utility model with the patent number CN202321678502.0 discloses a ranging device for forestry tree planting, which can be driven by a driving device. The ranging device performs fixed ranging on the ground, and cooperates with a recording device to leave ranging marks on the ground for convenient tree planting, thereby reducing the working steps of the device, improving the working efficiency of the device, and increasing the practicability. However, due to the different soil elevations in the forest farm, the existing forestry surveying and mapping ranging devices are difficult to perform equidistant and rapid ranging on the points to be planted on the land in the forest farm at different heights, and cannot improve the uniformity of the points to be planted, so further improvement is needed. Content of the Utility Model

[0004] In order to overcome the problem in the prior art that it is difficult to perform equidistant and rapid ranging on the points to be planted on the land in the forest farm at different heights, resulting in low point uniformity, a ranging device for forestry surveying and mapping is proposed.

[0005] The technical solution of the utility model is as follows: A ranging device for forestry surveying and mapping includes a bottom plate; a guiding rod is fixedly connected to the upper end of the bottom plate, a first measuring block is sleeved on the side wall of the guiding rod, a moving mechanism is arranged at the lower end of the bottom plate, a first groove is opened through the upper end of the first measuring block, grooves are opened on both sides of the inner wall of the first groove, a second measuring block is slidably arranged on the inner walls of the two grooves, a second fixing column is fixedly connected through the upper end of the second measuring block, a rotating block is sleeved on the side wall of the second fixing column, the side of the rotating block is U-shaped, a second electric cylinder is fixedly connected to the concave part of the rotating block, a positioning hole is opened at the side end of the second fixing column, and the positioning hole is adapted to the output shaft of the second electric cylinder. When the output shaft of the second electric cylinder is inserted into the positioning hole, the rotating block and the first measuring block are parallel to each other;

[0006] A positioning mechanism is installed on the rotating block, and a measuring rod is slidably arranged through the upper end of the rotating block;

[0007] A support block is fixedly connected to the upper end of the bottom plate, the side of the support block is L-shaped, and the upper end of the middle part of the support block is in contact with the lower end of the first measuring block;

[0008] A first scale wire groove is arranged at the upper end of the first measuring block, and a second scale wire groove is arranged at the upper end of the second measuring block;

[0009] The moving mechanism includes a first electric cylinder, a first fixed column, and rollers; two first electric cylinders are fixedly connected to the lower end of the bottom plate, the lower end of the output shaft of the first electric cylinder is fixedly connected to the first fixed column, and rollers are rotatably installed on both sides of the first fixed column;

[0010] A locking mechanism is provided on the second measuring block and the first measuring block together.

[0011] Furthermore, the outer diameter of the roller is greater than the outer diameter of the first fixed column, the upper end of the first measuring block is fixedly connected in a penetrating manner with a sliding cylinder, and the inner wall of the sliding cylinder fits against the side wall of the guide rod.

[0012] Furthermore, the positioning mechanism includes a limiting rod, an inner ring, an outer ring, a sleeve block, and an insertion rod. The lower end of the rotating block is fixedly connected to the limiting rod, the upper end of the bottom plate is fixedly connected to the inner ring and the outer ring. The outer diameter of the inner ring is smaller than the inner diameter of the outer ring. An insertion rod is slidably arranged on the inner wall of the annular groove between the inner ring and the outer ring. A sleeve block is sleeved on the side wall of the insertion rod, and the sleeve block is also sleeved on the side wall of the limiting rod. The lower end of the sleeve block fits against the upper end of the inner ring, and the upper ends of the inner ring and the outer ring are flush.

[0013] Furthermore, an arc-shaped block is fixedly connected to one side of the bottom plate, a limiting cylinder is fixedly connected to the upper end of the arc-shaped block, the inner diameter of the limiting cylinder is equal to the outer diameter of the measuring rod, and after the rotating block rotates along the central axis of the second fixed column, when the measuring rod moves upward and then is lowered, it will enter the inner wall of the limiting cylinder.

[0014] Furthermore, a storage battery and a controller are fixedly connected to the upper end of the bottom plate, and the first electric cylinder and the second electric cylinder are both electrically connected to the storage battery.

[0015] Furthermore, a U-shaped block is fixedly connected to the side end of the first measuring block, and the inner wall of the U-shaped block fits against the side wall of the support block.

[0016] Furthermore, a handle is fixedly connected in a penetrating manner to the upper parts of the side walls of the guide rod and the support block, and the top view of the handle is in a frame shape.

[0017] Furthermore, the locking mechanism includes a first screw hole, a second screw hole, and a bolt. A row of uniformly distributed first screw holes are penetrated and opened on one side of the first measuring block, uniformly distributed second screw holes are penetrated and opened on one side of the second measuring block, and a bolt is threadedly installed in the inner walls of the second screw hole and the first screw hole together.

[0018] Furthermore, limiting blocks are fixedly connected to both the upper and lower ends of the second measuring block, and both sides of the limiting blocks are respectively in contact with both side surfaces of the inner wall of the first groove body.

[0019] Furthermore, a fixed cylinder is fixedly connected in a penetrating manner to the upper end of the rotating block, and the inner wall of the fixed cylinder fits against the side wall of the measuring rod.

[0020] The beneficial effects of the present utility model:

[0021] 1. When the first electric cylinder drives the first fixed column to move up and down, the height of the roller is adjusted in real time to fit the ground with different slopes, ensuring that the guide rod is always perpendicular. After the first measuring block slides freely along the guide rod cylinder to the target height, a three-point support is formed through the L-shaped structure of the U-shaped block and the support block. At this time, the second measuring block is pulled out, and its limiting block slides along the groove of the first groove body. The extended length is quickly read through the first and second scale wire grooves. By rotating the rotating block around the second fixed column by an appropriate angle, the second electric cylinder accurately inserts the output shaft into the positioning hole to make the rotating block parallel to the first measuring block. Finally, the measuring rod in the fixed cylinder realizes the horizontal reference positioning, which is convenient for quickly determining the next planting point, solving the problem in the prior art that it is difficult to perform equidistant and rapid distance measurement on the points to be planted on the land in the forest farm at different heights, resulting in low point uniformity.

[0022] 2. After the insertion rod of the positioning mechanism is inserted into the soil, the sleeve block slides down along the limiting rod to the top surface of the inner ring, forming a triple limiting structure of the inner ring, outer ring and sleeve block, improving the anti-tilting ability of the device. By sequentially passing the bolts of the locking mechanism through the first screw hole and the second screw hole, the measuring block assembly is rigidly fixed. When the measuring rod completes the positioning, the measuring rod automatically falls into the guiding hole of the limiting cylinder when the rotating block resets, which is convenient for the temporary storage of the measuring rod when it is not in use and is easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The three-dimensional structure diagram of the present utility model is shown;

[0024] Figure 2 The three-dimensional structure diagram of the moving mechanism of the present utility model is shown;

[0025] Figure 3 The three-dimensional structure diagram of the second measuring block of the present utility model is shown;

[0026] Figure 4 The three-dimensional structure diagram of the first measuring block of the present utility model is shown;

[0027] Figure 5 The three-dimensional structure diagram of the support block of the present utility model is shown;

[0028] Figure 6 The three-dimensional structure diagram of the positioning mechanism of the present utility model is shown;

[0029] Figure 7 The three-dimensional structure diagram of the handle of the present utility model is shown.

[0030] The labels in the attached drawings are: 1, bottom plate; 2, guide rod; 3, first measuring block; 4, moving mechanism; 41, first electric cylinder; 42, first fixed column; 43, roller; 5, first groove; 6, recess; 7, second measuring block; 8, second fixed column; 9, rotating block; 10, second electric cylinder; 11, positioning hole; 12, first screw hole; 13, second screw hole; 14, bolt; 15, limiting block; 16, fixed cylinder; 17, measuring rod; 18, limiting rod; 19, support block; 20, U-shaped block; 21, storage battery; 22, controller; 23, arc-shaped block; 24, limiting cylinder; 25, inner ring; 26, outer ring; 27, sleeve block; 28, inserting rod; 29, handle. Detailed implementation mode

[0031] The present utility model will be further described below in conjunction with the attached drawings and embodiments.

[0032] Embodiment 1: Please refer to Figures 1-7 , a distance measuring device for forestry survey, comprising a bottom plate 1; a guide rod 2 is fixedly connected to the upper end of the bottom plate 1, a first measuring block 3 is sleeved on the side wall of the guide rod 2, a moving mechanism 4 is arranged at the lower end of the bottom plate 1, a first groove 5 is opened through the upper end of the first measuring block 3, grooves 6 are opened on both sides of the inner wall of the first groove 5, a second measuring block 7 is slidably arranged on the inner walls of the two grooves 6, a second fixed column 8 is fixedly connected through the upper end of the second measuring block 7, a rotating block 9 is sleeved on the side wall of the second fixed column 8, the side of the rotating block 9 is U-shaped, a second electric cylinder 10 is fixedly connected to the recess of the rotating block 9, a positioning hole 11 is opened at the side end of the second fixed column 8, the positioning hole 11 is adapted to the output shaft of the second electric cylinder 10, and when the output shaft of the second electric cylinder 10 is inserted into the positioning hole 11, the rotating block 9 and the first measuring block 3 are parallel to each other;

[0033] A positioning mechanism is installed on the rotating block 9, and a measuring rod 17 is slidably arranged through the upper end of the rotating block 9;

[0034] A support block 19 is fixedly connected to the upper end of the bottom plate 1, the side of the support block 19 is L-shaped, and the upper end of the middle part of the support block 19 is in contact with the lower end of the first measuring block 3;

[0035] A first scale line groove is arranged at the upper end of the first measuring block 3, and a second scale line groove is arranged at the upper end of the second measuring block 7;

[0036] The moving mechanism 4 includes a first electric cylinder 41, a first fixed column 42 and a roller 43; two first electric cylinders 41 are fixedly connected to the lower end of the bottom plate 1, the lower end of the output shaft of the first electric cylinder 41 is fixedly connected to the first fixed column 42, and rollers 43 are rotatably installed on both sides of the first fixed column 42;

[0037] A locking mechanism is jointly arranged on the second measuring block 7 and the first measuring block 3.

[0038] During use, the first measuring block 3 can slide along the side wall of the guide rod 2. The first measuring block 3 can be placed on the upper end of the support block 19. Taking the position where the guide rod 2 is located as the origin, the second measuring block 7 is drawn out from the inner wall of the first measuring block 3. According to the first scale groove and the second scale groove, the distance of the second measuring block 7 relative to the first measuring block 3 can be quickly judged. Then, the rotating block 9 is rotated, and the second electric cylinder 10 is activated so that the output shaft of the second electric cylinder 10 is inserted into the positioning hole 11. Since the length of the rotating block 9 is fixed, the position of the measuring rod 17 relative to the guide rod 2 can be quickly judged. Activating the first electric cylinder 41 can adjust the height of the first fixing column 42. Therefore, the guide rod 2 and the measuring rod 17 can be made to stand upright on the ground at different slopes, facilitating the quick measurement of the next planting point. Manually adjusting the positioning mechanism can facilitate the quick positioning of the device.

[0039] Please refer to Figure 1 , in this embodiment, the outer diameter of the roller 43 is larger than the outer diameter of the first fixing column 42. The upper end of the first measuring block 3 is fixedly connected in a penetrating manner with a sliding cylinder, and the inner wall of the sliding cylinder is in contact with the side wall of the guide rod 2. The precise fit between the sliding cylinder and the guide rod 2 ensures that the first measuring block 3 slides smoothly and without deviation.

[0040] Please refer to Figure 1 and Figure 6 , in this embodiment, an arc-shaped block 23 is fixedly connected to one side of the bottom plate 1, a limiting cylinder 24 is fixedly connected to the upper end of the arc-shaped block 23, the inner diameter of the limiting cylinder 24 is equal to the outer diameter of the measuring rod 17, and after the rotating block 9 rotates along the central axis of the second fixing column 8, when the measuring rod 17 moves upward and then is lowered, it will enter the inner wall of the limiting cylinder 24, which is beneficial to the stable placement of the measuring rod 17.

[0041] Please refer to Figure 1 and Figure 5 , in this embodiment, a storage battery 21 and a controller 22 are fixedly connected to the upper end of the bottom plate 1. The first electric cylinder 41 and the second electric cylinder 10 are both electrically connected to the storage battery 21, which is convenient for the device to be used in the wild.

[0042] Please refer to Figure 1 and Figure 5 , in this embodiment, a U-shaped block 20 is fixedly connected to the side end of the first measuring block 3, the inner wall of the U-shaped block 20 is in contact with the side wall of the support block 19, and the L-shaped structure of the U-shaped block 20 and the support block 19 forms a three-point rigid support, improving the stability of the first measuring block 3 during movement.

[0043] Please refer to Figure 1 and Figure 7 , in this embodiment, a handle 29 is fixedly connected in a penetrating manner to the upper parts of the side walls of the guide rod 2 and the support block 19. The top view of the handle 29 is in a frame shape, which is convenient for moving the device.

[0044] Please refer to Figure 1 and Figure 4 In this embodiment, a fixing cylinder 16 is fixedly connected through the upper end of the rotating block 9, and the inner wall of the fixing cylinder 16 is attached to the side wall of the measuring rod 17, facilitating the stable movement of the measuring rod 17 in the vertical direction.

[0045] Please refer to Figure 1 、 Figure 3 and Figure 4 In this embodiment, limiting blocks 15 are fixedly connected to both the upper and lower ends of the second measuring block 7, and both sides of the limiting blocks 15 are respectively attached to both side surfaces of the inner wall of the first groove body 5, facilitating the stable movement of the second measuring block 7.

[0046] Embodiment 2: Please refer to Figure 1 、 Figure 3 and Figure 4 On the basis of Embodiment 1, the present application provides a technical solution: The locking mechanism includes a first screw hole 12, a second screw hole 13, and a bolt 14. A row of uniformly distributed first screw holes 12 are formed through one side of the first measuring block 3, and uniformly distributed second screw holes 13 are formed through one side of the second measuring block 7. The inner walls of the second screw hole 13 and the first screw hole 12 are commonly threadedly installed with the bolt 14. Threadedly installing the bolt 14 into the inner walls of the second screw hole 13 and the first screw hole 12 at the same time can conveniently fix the second measuring block 7 on the first measuring block 3.

[0047] Embodiment 3: Please refer to Figure 3 、 Figure 4 and Figure 6 On the basis of Embodiment 1, the present application provides a technical solution: The positioning mechanism includes a limiting rod 18, an inner ring 25, an outer ring 26, a sleeve block 27, and a plug rod 28. The lower end of the rotating block 9 is fixedly connected with the limiting rod 18, the upper end of the bottom plate 1 is fixedly connected with the inner ring 25 and the outer ring 26. The outer diameter of the inner ring 25 is smaller than the inner diameter of the outer ring 26. A plug rod 28 is slidably arranged on the inner wall of the annular groove between the inner ring 25 and the outer ring 26. A sleeve block 27 is sleeved on the side wall of the plug rod 28, and the sleeve block 27 is also sleeved on the side wall of the limiting rod 18. The lower end of the sleeve block 27 is attached to the upper end of the inner ring 25, and the upper ends of the inner ring 25 and the outer ring 26 are flush. Inserting the plug rod 28 into the soil can improve the stability of the device when it is placed statically.

[0048] Working principle: When carrying out forestry exploration and ranging work, first use the moving mechanism 4 to adjust the position and height of the entire device to adapt to different terrains. Turn on the first electric cylinder 41, and adjust the height of the first fixed column 42 through the telescopic movement of its output shaft, so that the guide rod 2 and the measuring rod 17 can stand upright on the ground with different slopes;

[0049] After moving the device to the starting position of the measurement, use the positioning mechanism to improve the stability of the device when it is stationary. Insert the insertion rod 28 into the soil, and the sleeve block 27 slides down along the limit rod 18 and is placed at the upper ends of the inner ring 25 and the outer ring 26, so that the device can be stably placed on the ground;

[0050] Next, start the ranging operation. Pull out the second measuring block 7 from the inner wall of the first measuring block 3. By observing the first scale groove at the upper end of the first measuring block 3 and the second scale groove at the upper end of the second measuring block 7, the distance of the second measuring block 7 relative to the first measuring block 3 can be quickly judged;

[0051] When the second measuring block 7 is pulled out to the appropriate position, use the locking mechanism to fix the second measuring block 7 on the first measuring block 3. Thread the bolt 14 into the inner walls of the second screw hole 13 and the first screw hole 12 at the same time to complete the fixation;

[0052] Then rotate the rotating block 9. The side of the rotating block 9 is U-shaped, and a second electric cylinder 10 is fixedly connected to its concave part. A positioning hole 11 is opened at the side end of the second fixed column 8. The positioning hole 11 is adapted to the output shaft of the second electric cylinder 10. When the rotating block 9 rotates to the appropriate angle, turn on the second electric cylinder 10 so that the output shaft of the second electric cylinder 10 is inserted into the positioning hole 11. At this time, the rotating block 9 and the first measuring block 3 are parallel to each other;

[0053] Since the length of the rotating block 9 is fixed, combined with the previously measured distance of the second measuring block 7 relative to the first measuring block 3, the position of the measuring rod 17 relative to the guide rod 2 can be quickly judged. Manually mark the lower end of the measuring rod 17 to determine this point;

[0054] The upper end of the rotating block 9 is fixedly connected through the fixed cylinder 16. The inner wall of the fixed cylinder 16 fits with the side wall of the measuring rod 17, which is convenient for the stable movement of the measuring rod 17 in the vertical direction;

[0055] After the measurement is completed, the measuring rod 17 can be moved upward. After the rotating block 9 rotates along the central axis of the second fixed column 8, the measuring rod 17 is placed into the inner wall of the limit cylinder 24, which is convenient for storing the measuring rod 17;

[0056] During the whole operation process, a storage battery 21 and a controller 22 are fixedly connected to the upper end of the bottom plate 1. The first electric cylinder 41 and the second electric cylinder 10 are both electrically connected to the storage battery 21, which is convenient for the device to be used in the wild. At the same time, a handle 29 is fixedly connected through the upper parts of the side walls of the guide rod 2 and the support block 19. The top view of the handle 29 is frame-shaped, which is convenient for moving the device for the next measurement operation.

Claims

1. A distance measuring device for forestry survey, comprising a base plate (1); characterized in that: A guide rod (2) is fixedly connected to the upper end of the bottom plate (1), a first measuring block (3) is sleeved on the side wall of the guide rod (2), a moving mechanism (4) is provided on the lower end of the bottom plate (1), a first slot body (5) is penetrated through the upper end of the first measuring block (3), grooves (6) are provided on both sides of the inner wall of the first slot body (5), second measuring blocks (7) are slidably provided on the inner walls of the two grooves (6), a second fixed column (8) is penetrated and fixedly connected to the upper end of the second measuring block (7), a rotating block (9) is sleeved on the side wall of the second fixed column (8), the side surface of the rotating block (9) is U-shaped, a second electric cylinder (10) is fixedly connected to the recessed part of the rotating block (9), a positioning hole (11) is provided on the side end of the second fixed column (8), the positioning hole (11) is matched with the output shaft of the second electric cylinder (10), and when the output shaft of the second electric cylinder (10) is inserted into the positioning hole (11), the rotating block (9) and the first measuring block (3) are parallel to each other; A positioning mechanism is installed on the rotating block (9), and a measuring rod (17) is slidably provided through the upper end of the rotating block (9); A support block (19) is fixedly connected to the upper end of the bottom plate (1), the side surface of the support block (19) is L-shaped, and the upper end of the middle portion of the support block (19) is in contact with the lower end of the first measuring block (3); The first measuring block (3) has a first scale line groove at its upper end, and the second measuring block (7) has a second scale line groove at its upper end; The moving mechanism (4) comprises a first electric cylinder (41), a first fixed column (42) and a roller (43); the lower end of the base plate (1) is fixedly connected to two first electric cylinders (41), the lower end of the output shaft of the first electric cylinder (41) is fixedly connected to the first fixed column (42), and rollers (43) are rotatably mounted on both sides of the first fixed column (42); The second measuring block (7) and the first measuring block (3) are both provided with a locking mechanism.

2. The distance measuring device for forestry survey according to claim 1, characterized in that: The outer diameter of the roller (43) is greater than the outer diameter of the first fixed column (42); a slide cylinder is fixedly connected through the upper end of the first measuring block (3); and the inner wall of the slide cylinder is in contact with the side wall of the guide rod (2).

3. The distance measuring device for forestry survey according to claim 1, characterized in that: The positioning mechanism comprises a limit rod (18), an inner ring (25), an outer ring (26), a sleeve block (27) and an insertion rod (28). The lower end of the rotating block (9) is fixedly connected to the limit rod (18), the upper end of the bottom plate (1) is fixedly connected to the inner ring (25) and the outer ring (26), the outer diameter of the inner ring (25) is smaller than the inner diameter of the outer ring (26), the insertion rod (28) is slidably arranged on the inner wall of the annular groove between the inner ring (25) and the outer ring (26), the side wall of the insertion rod (28) is sleeved with a sleeve block (27), the sleeve block (27) is also sleeved on the side wall of the limit rod (18), the lower end of the sleeve block (27) is in contact with the upper end of the inner ring (25), and the upper ends of the inner ring (25) and the outer ring (26) are flush.

4. The distance measuring device for forestry survey according to claim 1, characterized in that: An arc block (23) is fixedly connected to one side of the bottom plate (1), and an upper end of the arc block (23) is fixedly connected to a limiting cylinder (24). The inner diameter of the limiting cylinder (24) is equal to the outer diameter of the measuring rod (17). After the rotating block (9) rotates along the central axis of the second fixed column (8), the measuring rod (17) moves upward and then lowers to enter the inner wall of the limiting cylinder (24).

5. The distance measuring device for forestry survey according to claim 1, characterized in that: A storage battery (21) and a controller (22) are fixedly connected to the upper end of the base plate (1), and both the first electric cylinder (41) and the second electric cylinder (10) are electrically connected to the storage battery (21).

6. The distance measuring device for forestry survey according to claim 1, characterized in that: A U-shaped block (20) is fixedly connected to the side end of the first measuring block (3), and the inner wall of the U-shaped block (20) is in contact with the side wall of the supporting block (19).

7. The distance measuring device for forestry survey according to claim 1, characterized in that: A handle (29) is fixedly connected to the upper part of the side wall of the guide rod (2) and the support block (19) through the handle (29), and the top surface of the handle (29) is frame-shaped.

8. The distance measuring device for forestry survey according to claim 1, characterized in that: The locking mechanism comprises a first screw hole (12), a second screw hole (13) and a bolt (14); one side of the first measuring block (3) is penetrated by a row of evenly distributed first screw holes (12); one side of the second measuring block (7) is penetrated by a evenly distributed second screw holes (13); and the inner walls of the second screw holes (13) and the first screw holes (12) are threadedly mounted with the bolt (14).

9. The distance measuring device for forestry survey according to claim 1, characterized in that: The upper and lower ends of the second measuring block (7) are fixedly connected to the limit blocks (15), and the two sides of the limit blocks (15) are respectively fitted with the two side surfaces of the inner wall of the first trough body (5).

10. The distance measuring device for forestry survey according to claim 1, characterized in that: A fixed cylinder (16) is fixedly connected to the upper end of the rotating block (9) in a penetrating manner, and the inner wall of the fixed cylinder (16) is in contact with the side wall of the measuring rod (17).

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