A wall tilt detection device for building construction

By using a sector wheel and rotating wheel structure to amplify the measurement angle in the wall tilt detection device, and combining it with a flatness detection mechanism and marking components, the problem of insufficient detection accuracy is solved, and a high-precision wall tilt detection and repair solution is achieved.

CN116878464BActive Publication Date: 2026-06-30RUIZHOU CONSTR GRP CO LTD

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
RUIZHOU CONSTR GRP CO LTD
Filing Date
2023-07-10
Publication Date
2026-06-30

AI Technical Summary

Technical Problem

The existing wall tilt detection device is not accurate enough, and the large range of the angle sensor leads to large measurement errors, which affects the detection results.

Method used

The system employs a combination of fan-shaped wheels and rotating wheels to amplify the rotation angle of the measuring plate, and improves detection accuracy and provides a visual repair solution through a flatness detection mechanism and marking components.

Benefits of technology

It improves the accuracy of wall tilt detection, can accurately mark the position of the groove and adjust the amount of pigment according to the depth of the groove, making it convenient for construction workers to plan repairs reasonably.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN116878464B_ABST
    Figure CN116878464B_ABST
Patent Text Reader

Abstract

This invention discloses a wall tilt detection device for building construction. A universal wheel is fixed to the bottom of the base. A lateral displacement component is fixed to the base, and the lateral displacement component includes a sliding seat. A longitudinal displacement component is vertically fixed to the sliding seat, and the longitudinal displacement component includes a lifting seat. A measuring plate is hinged to one end of the bottom of the lifting seat. A sector wheel is fixed to the inner side of the measuring plate. A rotating wheel is rotatably connected to the side wall of the lifting seat, and the rotating wheel and the sector wheel are in frictional contact. A winding wheel is coaxially fixed to one side of the rotating wheel, and a rope is wound on the winding wheel. The free end of the rope is fixedly connected to a tension gauge, which is fixed to the lifting seat. A flatness detection mechanism is also fixed to the measuring plate. This invention, through the cooperation of the sector wheel, rotating wheel, and other structures, can amplify the rotation angle of the measuring plate, avoiding angle measurement errors caused by a large measuring range, thereby improving detection accuracy.
Need to check novelty before this filing date? Find Prior Art

Description

Technical Field

[0001] This invention relates to the field of wall tilt detection technology, and more specifically, to a wall tilt detection device for building construction. Background Technology

[0002] In the prior art, such as Chinese invention patent with publication number CN115839705B, a wall tilt detection device for building construction is disclosed. It is equipped with a flatness detection mechanism. The detection rod is attached to the wall surface. The flatness detection mechanism collects gas and adds gas to the inside of the telescopic sleeve through the gas supply pipe, causing the sleeve to extend. The pressure sensor at one end of each telescopic sleeve is independently controlled. When the pressure sensor touches the wall surface, the individual telescopic sleeve stops extending. When all of them stop, the gas flow rate can be detected by the gas flow meter. The gas flow rate data is transmitted to the transmitter through the transmission line. By comparing the data with the extension length data of the telescopic sleeve, the flatness of the wall surface can be determined.

[0003] However, the above technical solutions have the following defects: According to the notice issued by the Ministry of Construction regarding the release of the industry standard "Standard for Identification of Dangerous Buildings", it is clearly stipulated that when a wall or column tilts and its tilt rate is greater than 0.7%, or when the connection between adjacent walls is broken into a continuous crack, it should be assessed as a dangerous point. That is, the tilt of the building wall is usually less than 0.7%, which makes the rotation angle of the detection rod small and can only output a relatively narrow voltage range. However, the range of the angle sensor is usually relatively large, resulting in a large angle measurement error value, which affects the accuracy of the detection results. Summary of the Invention

[0004] The technical problem this invention aims to solve is that existing wall tilt detection devices lack sufficient detection accuracy. To overcome the shortcomings of the prior art, this invention proposes a wall tilt detection device for building construction. Through the cooperation of structures such as fan-shaped wheels and rotating wheels, the rotation angle of the measuring plate can be amplified to avoid angle measurement errors caused by a large measuring range, thereby improving detection accuracy.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] This invention provides a wall tilt detection device for building construction, including a base, casters, a tilt detection mechanism, and a flatness detection mechanism. The casters are fixed to the bottom of the base, and the tilt detection mechanism is fixed to the base. The tilt detection mechanism includes a lateral displacement component, a longitudinal displacement component, a measuring plate, a fan-shaped wheel, a rotating wheel, a winding wheel, a rope, and a tension gauge. The lateral displacement component is fixed to the base and includes a sliding seat. A longitudinal displacement component is vertically fixed to the sliding seat, and the longitudinal displacement component includes a lifting seat. A measuring plate is hinged to one end of the bottom of the lifting seat. A fan-shaped wheel is fixed to the inner side of the measuring plate. A rotating wheel is rotatably connected to the side wall of the lifting seat and is frictionally connected to the fan-shaped wheel. A winding wheel is coaxially fixed to one side of the rotating wheel, and a rope is wound on the winding wheel. The free end of the rope is fixedly connected to a tension gauge, which is fixed to the lifting seat. A flatness detection mechanism is also fixed to the measuring plate.

[0007] In a preferred embodiment of the present invention, the lateral displacement assembly further includes a first motor and a first lead screw. The first motor is fixed on the base, and the first lead screw is fixed on the power output end of the first motor. A first sliding groove is provided on the base, and the sliding seat is slidably connected in the first sliding groove. The first lead screw is threadedly connected to the sliding seat.

[0008] In a preferred embodiment of the present invention, the longitudinal displacement assembly further includes a sliding guide rail, a second motor, and a second lead screw. The sliding guide rail is vertically fixed on the sliding seat, and the lifting seat is slidably connected to the sliding guide rail. The second motor is fixed on the sliding seat, and the second lead screw is fixed to the power output end of the second motor, and the second lead screw is threadedly connected to the lifting seat.

[0009] In a preferred embodiment of the present invention, the flatness detection mechanism includes an outer tube, an inner tube, a ball socket, a steel ball, a first piston, an air inlet pipe, a diverter pipe, and an air pump. Two or more outer tubes are uniformly fixed on the side of the measuring plate away from the lifting seat. An inner tube is slidably connected inside the outer tube. A ball socket is fixed at one end of the inner tube, and a steel ball is fixed inside the ball socket. A first piston is fixed at the other end of the inner tube and is slidably connected inside the outer tube. An air inlet pipe is fixed on one side of the measuring plate and is connected to the outer tube through a diverter pipe. An air pump is also fixed on the air inlet pipe.

[0010] In a preferred embodiment of the present invention, a limiting block is also fixed on the inner wall of the outer tube.

[0011] In a preferred embodiment of the present invention, the flatness detection mechanism further includes a marking assembly, which includes a second piston, a permanent magnet, a connecting rod, an iron core, and an electromagnetic coil. The second piston is slidably connected to the inner side of the inner tube, the permanent magnet is embedded in the second piston, the iron core is slidably connected to the outer tube, and the iron core is connected to the first piston through the connecting rod. The electromagnetic coil is embedded in the inner wall of the outer tube, and the surface of the steel ball is also provided with a through hole, which communicates with the inner tube.

[0012] In a preferred embodiment of the present invention, the marking assembly further includes a pigment tube, a retractable hose, and a one-way valve. The pigment tube is fixed to the measuring plate, and a discharge port is provided on one side of the pigment tube. One end of the retractable hose is connected to the discharge port, and the other end of the retractable hose is fixed to the second piston. A one-way valve is also fixed to the discharge port.

[0013] In a preferred embodiment of the present invention, a level is also fixed on the base.

[0014] The beneficial effects of this invention are as follows:

[0015] This invention proposes a wall tilt detection device for building construction. Through the cooperation of structures such as fan-shaped wheels and rotating wheels, the rotation angle of the measuring plate can be amplified to avoid angle measurement errors caused by a large measuring range, thereby improving detection accuracy. The flatness detection mechanism can detect the flatness of the wall surface and mark the grooved areas to facilitate later repairs by workers. Furthermore, the marking component can adjust the amount of pigment used according to the groove depth, making the marking results more intuitive and facilitating workers to plan repair schemes rationally. Attached Figure Description

[0016] Figure 1 This is a structural schematic diagram of a wall tilt detection device for building construction provided in a specific embodiment of the present invention;

[0017] Figure 2 yes Figure 1 A magnified view of a section at point A in the middle;

[0018] Figure 3 yes Figure 1 The right view;

[0019] Figure 4 yes Figure 3 A magnified view of a section at point B.

[0020] In the picture:

[0021] 1. Base; 2. Casters; 3. Inclination detection mechanism; 31. Lateral displacement assembly; 311. Sliding seat; 312. First motor; 313. First lead screw; 314. First slide rail; 32. Longitudinal displacement assembly; 321. Lifting seat; 322. Sliding guide rail; 323. Second motor; 324. Second lead screw; 33. Measuring plate; 34. Sector wheel; 35. Rotating wheel; 36. Winding wheel; 37. Rope; 38. Pulling rod 4. Force gauge; 4. Flatness testing mechanism; 41. Outer tube; 42. Inner tube; 43. Ball socket; 44. Steel ball; 45. First piston; 46. Air inlet pipe; 47. Diverter pipe; 48. Air pump; 49. Limiting block; 5. Marking assembly; 51. Second piston; 52. Permanent magnet; 53. Connecting rod; 54. Iron core; 55. Electromagnetic coil; 56. Through hole; 57. Pigment tube; 58. Telescopic flexible hose; 59. One-way valve; 6. Level. Detailed Implementation

[0022] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] like Figure 1-4As shown, the embodiment provides a wall tilt detection device for building construction, including a base 1, casters 2, tilt detection mechanism 3, and flatness detection mechanism 4. Casters 2 are fixed to the bottom of the base 1, and the tilt detection mechanism 3 is fixed to the base 1. The tilt detection mechanism 3 includes a lateral displacement component 31, a longitudinal displacement component 32, a measuring plate 33, a sector wheel 34, a rotating wheel 35, a winding wheel 36, a rope 37, and a tension gauge 38. The lateral displacement component 31 is fixed to the base 1 and includes a sliding seat 311. A vertical... A longitudinal displacement assembly 32 is fixedly provided, including a lifting base 321. A measuring plate 33 is hinged to one end of the bottom of the lifting base 321. A sector wheel 34 is fixedly provided on the inner side of the measuring plate 33. A rotating wheel 35 is rotatably connected to the side wall of the lifting base 321, and the rotating wheel 35 is in frictional contact with the sector wheel 34. A winding wheel 36 is coaxially fixed on one side of the rotating wheel 35. A rope 37 is wound on the winding wheel 36. The free end of the rope 37 is fixedly connected to a tension gauge 38, which is fixedly mounted on the lifting base 321. A flatness detection mechanism 4 is also fixedly provided on the measuring plate 33. In this embodiment, a universal wheel 2 is fixedly provided at each of the four corners of the bottom of the base 1, so as to facilitate pushing the equipment to the construction position. The tilt detection mechanism 3 is used to detect the tilt of the wall surface. The lateral displacement component 31 and the longitudinal displacement component 32 cooperate to adjust the position of the measuring plate 33, allowing for measurement of multiple parts of the wall surface without changing the reference plane, thus improving detection efficiency. The lifting seat 321 has an L-shaped structure, with the measuring plate 33 positioned below it and its top hinged to the bottom of the lifting seat 321, enabling the measuring plate 33 to rotate. A sector wheel 34 is vertically positioned on one side of the lifting seat 321 and is fixedly connected to the measuring plate 33, allowing the measuring plate 33 to rotate. The sector wheel 34 does not interfere with the lifting seat 321. At the same time, the diameter of the sector wheel 34 should be much larger than the diameter of the rotating wheel 35, thereby amplifying the rotation angle of the sector wheel 34. The amplification factor is the ratio of the diameters of the sector wheel 34 and the rotating wheel 35. The tension gauge 38 is a spring tension gauge. The spring deformation can be obtained through the elastic coefficient and tension value of the tension gauge 38, and then the rotation angle of the rotating wheel 35 can be calculated. Then, by dividing by the amplification factor, the rotation angles of the sector wheel 34 and the measuring plate 33 can be obtained. Compared with the existing detection device, the reading is more accurate. The flatness detection mechanism 4 is used to detect the flatness of the wall surface.

[0024] Specifically, the lateral displacement assembly 31 also includes a first motor 312 and a first lead screw 313. The first motor 312 is fixed to the base 1, and the first lead screw 313 is fixed to the power output end of the first motor 312. A first sliding groove 314 is provided on the base 1, and a sliding seat 311 is slidably connected to the first sliding groove 314, with the first lead screw 313 threadedly connected to the sliding seat 311. In this embodiment, the first sliding groove 314 is arranged parallel to the wall, allowing the sliding seat 311 to move parallel to the wall to adjust the position of the measuring plate 33. The first motor 312 drives the first lead screw 313 to rotate, thereby causing the sliding seat 311 to slide within the first sliding groove 314.

[0025] Specifically, the longitudinal displacement component 32 further includes a sliding guide rail 322, a second motor 323, and a second lead screw 324. The sliding guide rail 322 is vertically fixed on the sliding seat 311, and a lifting seat 321 is slidably connected to the sliding guide rail 322. The second motor 323 is fixed on the sliding seat 311, and the second lead screw 324 is fixed to the power output end of the second motor 323, and the second lead screw 324 is threadedly connected to the lifting seat 321. In this embodiment, the sliding guide rail 322 is vertically arranged, allowing the lifting seat 321 to move up and down to adjust the height of the measuring plate 33. The second motor 323 drives the second lead screw 324 to move, thereby causing the lifting seat 321 to slide.

[0026] Specifically, the flatness testing mechanism 4 includes an outer tube 41, an inner tube 42, a ball socket 43, a steel ball 44, a first piston 45, an air inlet pipe 46, a diverter pipe 47, and an air pump 48. Two or more outer tubes 41 are uniformly fixed on the side of the measuring plate 33 away from the lifting seat 321. An inner tube 42 is slidably connected inside the outer tube 41. A ball socket 43 is fixed at one end of the inner tube 42, and a steel ball 44 is fixed inside the ball socket 43. A first piston 45 is fixed at the other end of the inner tube 42 and is slidably connected inside the outer tube 41. The air inlet pipe 46 is fixed on one side of the measuring plate 33 and communicates with the outer tube 41 through the diverter pipe 47. An air pump 48 is also fixed on the air inlet pipe 46. In this embodiment, two or more outer tubes 41 are uniformly arranged along the length of the measuring plate 33, and the outer tubes 41 are arranged perpendicular to the measuring plate 33. Each outer tube 41 is equipped with an inner tube 42, and the length of the inner tube 42 should be less than the length of the outer tube 41 so that the inner tube 42 can be completely housed within the outer tube 41. One end of the steel ball 44 protrudes from the socket 43. Since the contact point between the steel ball 44 and the wall surface is extremely small, it is not easily affected by the flatness of the area around the contact point with the wall surface. This avoids the situation where the contact area between the detection part and the wall surface is too large, causing it to fail to contact the small recess, thereby improving the accuracy of the detection. The first piston 45 can seal the cavity on the right side, so that when the air pump 48 inflates or deflates the outer tube 41, it can push the first piston 45 to slide inside the outer tube 41 to control the extension or retraction of the inner tube 42.

[0027] Specifically, a limiting block 49 is also fixed on the inner wall of the outer tube 41. In this embodiment, the movement range of the inner tube 42 can be limited by setting the limiting block 49.

[0028] Specifically, the flatness detection mechanism 4 also includes a marking component 5. The marking component 5 includes a second piston 51, a permanent magnet 52, a connecting rod 53, an iron core 54, and an electromagnetic coil 55. The second piston 51 is slidably connected to the inner side of the inner tube 42, the permanent magnet 52 is embedded in the second piston 51, the iron core 54 is slidably connected to the outer tube 41, and the iron core 54 is connected to the first piston 45 through the connecting rod 53. The electromagnetic coil 55 is embedded in the inner wall of the outer tube 41, and a through hole 56 is also provided on the surface of the steel ball 44, which communicates with the inner tube 42. In this embodiment, the marking component 5 is used to mark the location of wall depressions, which facilitates later repairs by construction personnel. The inner tube 42 contains pigment, which is squeezed through the through hole 56 into the recessed area of ​​the wall to achieve the purpose of marking. The length of the iron core 54 is the same as the length of the electromagnetic coil 55. Utilizing the principle that the more turns of the electromagnetic coil 55 wound on the iron core 54, the greater the electromagnetic force, the deeper the wall recess, the longer the inner tube 42 extends. At this time, the inner tube 42 will drive the iron core 54 to move synchronously, which will increase the number of turns of the electromagnetic coil 55 wound on the iron core 54, thereby increasing the magnetic force of the electromagnetic coil 55. The increased magnetism of the electromagnetic coil 55 will push the displacement of the second piston 51 to increase, thereby increasing the amount of pigment squeezed out. That is, the deeper the recess, the more pigment is in the groove, which makes it easier for the staff to reasonably plan the repair scheme.

[0029] Specifically, the marking component 5 also includes a pigment tube 57, a retractable hose 58, and a one-way valve 59. The pigment tube 57 is fixed to the measuring plate 33, and a discharge port is provided on one side of the pigment tube 57. One end of the retractable hose 58 is connected to the discharge port, and the other end of the retractable hose 58 is fixed to the second piston 51. A one-way valve 59 is also fixed to the discharge port. In this embodiment, the pigment tube 57 stores pigment, and the pigment tube 57 is also provided with a squeezing plate. One end of the pressing handle is fixed to the squeezing plate, so that the pigment in the pigment tube 57 can be manually squeezed into the inner tube 42 to replenish the pigment. The retractable hose 58 is made of flexible material and can be freely extended and retracted. The one-way valve 59 can prevent the pigment in the inner tube 42 from flowing back into the pigment tube 57 during the squeezing process of the second piston 51.

[0030] Specifically, a level 6 is also fixed on the base 1. In this embodiment, by setting the level 6, it is convenient for the staff to adjust the base 1 to a horizontal state, so as to ensure the accuracy of the measurement results.

[0031] Working principle: When using this device, first move the base 1 to the position to be constructed, and gradually press the measuring plate 33 against the wall. At this time, the measuring plate 33 will rotate until it is parallel to the wall. During the rotation of the measuring plate 33, the sector wheel 34 will rotate synchronously. The rotation of the sector wheel 34 will drive the rotating wheel 35 to rotate, and the rotation of the rotating wheel 35 will drive the winding wheel 36 to rotate. The rotation of the winding wheel 36 will wind the rope 37, which will cause the tension gauge 38 to stretch. The operator can obtain the spring deformation by the elastic coefficient and tension value of the tension gauge 38, and then calculate the rotation angle of the rotating wheel 35. Then, divide by the magnification factor to obtain the rotation angle of the sector wheel 34 and the measuring plate 33, that is, the inclination of the wall. The reading is more accurate after the angle is magnified.

[0032] Then, the air pump 48 is started. The air pump 48 inflates the outer tube 41 through the air inlet pipe 46 and the diverter pipe 47, thereby pushing the first piston 45 to slide inside the outer tube 41. The sliding of the first piston 45 causes the inner tube 42 to extend out of the outer tube 41, and the steel ball 44 to abut against the groove on the wall. At the same time, the sliding of the first piston 45 will cause the iron core 54 to be inserted into the electromagnetic coil 55. At this time, the electromagnetic coil 55 is energized. After the electromagnetic coil 55 generates magnetic force, it will repel the permanent magnet 52, thereby causing the second piston 51 to move away from the first piston 45, thereby squeezing the pigment in the inner tube 42 through the through hole 56 to the groove on the wall, achieving the marking effect. After the wall flatness test is completed, the electromagnetic coil 55 is energized in reverse, so that the electromagnetic coil 55 and the permanent magnet 52 are attracted, thereby causing the second piston 51 to reset. Then, the air pump 48 evacuates air outward, causing the inner tube 42 to reset, completing the entire test process.

[0033] This invention has been described through preferred embodiments. Those skilled in the art will understand that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. This invention is not limited to the specific embodiments disclosed herein; other embodiments falling within the scope of the claims are also within the protection scope of this invention.

Claims

1. A wall tilt detection device for building construction, characterized in that: The system includes a base (1), casters (2), a tilt detection mechanism (3), and a flatness detection mechanism (4). The base (1) is fixed with casters (2) at its bottom and tilt detection mechanism (3) is fixed on the base (1). The tilt detection mechanism (3) includes a lateral displacement component (31), a longitudinal displacement component (32), a measuring plate (33), a fan-shaped wheel (34), a rotating wheel (35), a winding wheel (36), a rope (37), and a tension gauge (38). The lateral displacement component (31) is fixed on the base (1) and includes a sliding seat (311). The longitudinal displacement component (38) is vertically fixed on the sliding seat (311). 2) The longitudinal displacement component (32) includes a lifting seat (321), a measuring plate (33) is hinged to one end of the bottom of the lifting seat (321), a fan-shaped wheel (34) is fixed on the inner side of the measuring plate (33), a rotating wheel (35) is rotatably connected to the side wall of the lifting seat (321), and the rotating wheel (35) is frictionally connected to the fan-shaped wheel (34). A winding wheel (36) is coaxially fixed on one side of the rotating wheel (35), a rope (37) is wound on the winding wheel (36), the free end of the rope (37) is fixedly connected to the tension gauge (38), and the tension gauge (38) is fixed on the lifting seat (321). A flatness detection mechanism (4) is also fixed on the measuring plate (33). The flatness testing mechanism (4) includes an outer tube (41), an inner tube (42), a ball socket (43), a steel ball (44), a first piston (45), an air inlet pipe (46), a diverter pipe (47), and an air pump (48). Two or more outer tubes (41) are uniformly fixed on the side of the measuring plate (33) away from the lifting seat (321). The inner tube (42) is slidably connected inside the outer tube (41). A ball socket (43) is fixed at one end of the inner tube (42), and a steel ball (44) is fixed inside the ball socket (43). The first piston (45) is fixed at the other end of the inner tube (42), and the first piston (45) is slidably connected inside the outer tube (41). The air inlet pipe (46) is fixed on one side of the measuring plate (33), and the air inlet pipe (46) is connected to the outer tube (41) through the diverter pipe (47). An air pump (48) is also fixed on the air inlet pipe (46). The flatness detection mechanism (4) further includes a marking component (5), which includes a second piston (51), a permanent magnet (52), a connecting rod (53), an iron core (54), and an electromagnetic coil (55). The second piston (51) is slidably connected to the inner side of the inner tube (42), the permanent magnet (52) is embedded in the second piston (51), the iron core (54) is slidably connected to the outer tube (41), and the iron core (54) is connected to the first piston (45) through the connecting rod (53). The electromagnetic coil (55) is embedded in the inner wall of the outer tube (41). The surface of the steel ball (44) is also provided with a through hole (56), and the through hole (56) is connected to the inner tube (42).

2. The wall tilt detection device for building construction according to claim 1, characterized in that: The lateral displacement assembly (31) further includes a first motor (312) and a first lead screw (313). The first motor (312) is fixed on the base (1), and the first lead screw (313) is fixed on the power output end of the first motor (312). A first sliding groove (314) is provided on the base (1). The sliding seat (311) is slidably connected in the first sliding groove (314), and the first lead screw (313) is threadedly connected to the sliding seat (311).

3. The wall tilt detection device for building construction according to claim 1, characterized in that: The longitudinal displacement component (32) further includes a sliding guide rail (322), a second motor (323), and a second lead screw (324). The sliding guide rail (322) is vertically fixed on the sliding seat (311), and the lifting seat (321) is slidably connected to the sliding guide rail (322). The second motor (323) is fixed on the sliding seat (311), and the second lead screw (324) is fixed at the power output end of the second motor (323), and the second lead screw (324) is threadedly connected to the lifting seat (321).

4. The wall tilt detection device for building construction according to claim 3, characterized in that: A limiting block (49) is also fixed on the inner wall of the outer tube (41).

5. A wall tilt detection device for building construction according to claim 1, characterized in that: The marking assembly (5) also includes a pigment tube (57), a retractable hose (58), and a one-way valve (59). The pigment tube (57) is fixed on the measuring plate (33). A discharge port is provided on one side of the pigment tube (57). One end of the retractable hose (58) is connected to the discharge port. The other end of the retractable hose (58) is fixed on the second piston (51). A one-way valve (59) is also fixed on the discharge port.

6. The wall tilt detection device for building construction according to claim 1, characterized in that: A level (6) is also fixed on the base (1).