Foundation pit supporting pile

Abstract

The utility model relates to the technical field of foundation pit supporting, and discloses a foundation pit supporting pile which comprises a fixed pile, supporting rods are fixedly connected to the periphery of the outer wall of the fixed pile, a rotating shaft is rotationally connected to one side of the outer wall of each supporting rod, and a telescopic pile is rotationally connected to the other side of the outer wall of each rotating shaft. A limiting rod is rotatably connected to the middle of the outer wall of the telescopic pile, a sliding block is arranged at the bottom of the outer wall of the hydraulic push rod and slidably connected to the middle of the inner wall of the adjusting plate, and a connecting mechanism is fixedly connected to the top of the fixed pile and used for achieving rapid clamping and fixing. According to the foundation pit supporting structure, the fixed pile serves as a foundation support, the supporting rod connected with the fixed pile is used for expanding the supporting range, flexibly adjusting the stretching angle of the telescopic pile and ensuring stable action of the hydraulic push rod, the foundation pit supporting structure is particularly suitable for narrow or complex terrains, material and design optimization reduces cost, and construction efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of foundation pit support technology, and in particular to a foundation pit support pile. Background Technology

[0002] Pit support piles are an important support structure widely used in the construction of foundation pits in building engineering. They are made of reinforced concrete and other materials, and are vertically installed around the perimeter of the foundation pit using pile forming processes such as bored piles and precast piles. During the excavation of the foundation pit, a support structure is required to ensure the stability of the foundation pit and construction safety. As a common form of foundation pit support, support piles are widely used in various foundation pit projects due to their advantages of strong bearing capacity, convenient construction, and strong adaptability. However, with the continuous expansion of the scale of foundation pit projects and the increasing complexity of geological conditions, higher requirements are placed on the performance of support piles.

[0003] A search revealed Chinese Patent Publication No. CN114934521B, which discloses a foundation pit support pile, specifically relating to the field of foundation pit support. The pile includes a first support mechanism and a second support mechanism, with a third support mechanism fixedly installed between the two. The first support mechanism includes a first limiting support plate fixedly installed on one side of the wall. The second support mechanism includes a second limiting support plate fixedly installed on the ground. The third support mechanism includes a third limiting support plate supported between the first limiting support plate and a supporting column. Connecting blocks are hinged to both sides of the third limiting support plate, and connecting plates are fixedly installed on both sides of the connecting blocks. The first and second limiting support plates are arranged in a U-shape. This invention is based on the solution color within the reaction chamber... The color change allows workers to initially determine if the wall has tilted, and the presence or absence of water in the storage tank indicates ground tilt, making it easier to use in practice. However, in existing foundation pit support piles, under complex geological conditions, the bearing capacity of the support piles is insufficient to meet engineering requirements. When construction conditions are complex, in narrow spaces and complex terrain areas, space constraints increase the difficulty of support pile construction, making it difficult to guarantee construction quality. In large-scale foundation pit projects, the large number and specifications of support piles required lead to a significant increase in construction costs. Insufficient bearing capacity leads to the demand for higher-specification support piles, further increasing costs. The high construction difficulty not only affects quality but also further increases costs, restricting the application and development of foundation pit support pile technology in actual engineering projects. Utility Model Content

[0004] To overcome the above shortcomings, this utility model provides a foundation pit support pile, which aims to improve the existing technology in complex geological conditions, where it is difficult to meet engineering requirements, and where construction conditions are complex. In narrow spaces and complex terrain areas, the construction difficulty of support piles increases, thereby increasing costs and further pushing up costs, which restricts the application and development of foundation pit support pile technology in actual engineering.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a foundation pit support pile, comprising a fixed pile, with support rods fixedly connected to the outer wall of the fixed pile around its perimeter. A rotating shaft is rotatably connected to one side of the outer wall of each of the support rods. A telescopic pile is rotatably connected to the other side of the outer wall of the rotating shaft. A limit rod is rotatably connected to the middle of the outer wall of the telescopic pile. An adjusting plate is rotatably connected to the other end of the telescopic pile. Support blocks are fixedly connected at equal intervals to the inner wall of the adjusting plate. Hydraulic push rods are rotatably connected to the bottom perimeter of the fixed pile. One end of the hydraulic push rod is rotatably connected to the top of the outer wall of the telescopic pile. A slider is provided at the bottom of the outer wall of the hydraulic push rod. The slider is slidably connected to the middle of the inner wall of the adjusting plate. A connecting mechanism is fixedly connected to the top of the fixed pile, and the connecting mechanism is used to achieve quick locking and fixing.

[0006] The above technical solution utilizes fixed piles as the foundation support in the foundation pit support structure. Connected support rods extend the support range. A rotating shaft allows the support rods and telescopic piles to rotate relative to each other to adapt to different foundation pit requirements. Limiting rods restrict the telescopic range of the telescopic piles to ensure safe operation. Adjusting plates further adjust the support angle and position. Support blocks provide multi-point support to enhance stability. Hydraulic push rods connect to the telescopic piles, adjusting the support force through telescopic movements. Slider blocks assist in adjusting angle changes to ensure smooth operation. The entire structure can be flexibly adjusted according to the foundation pit conditions, providing stable support, enhancing load-bearing capacity, reducing costs and environmental impact, and is suitable for complex terrain. Optimized materials and design improve construction efficiency.

[0007] As a further description of the above technical solution:

[0008] The connecting mechanism includes a docking groove, which is fixedly connected to the middle of the inner wall of the fixed pile. Limiting plates are fixedly connected to the front and rear sides of the outer wall of the docking groove. A locking ring is fixedly connected to the top of the outer wall of the docking groove. A fixing rod is rotatably connected to the left side of the outer wall of the locking ring. A limiting block is threadedly connected to the front side of the outer wall of the fixing rod. A fixing groove is fixedly connected to the bottom of the inner wall of the fixed pile. A limiting ring is fixedly connected to the top of the outer wall of the fixing groove.

[0009] Through the above technical solution: the connecting mechanism can quickly connect and fix with the fixed pile through its internal structure. The docking groove is located in the middle of the inner wall of the fixed pile. The limiting plate prevents the components from moving back and forth, ensuring precise docking. The locking ring and the fixing rod work together to rotate and lock the fixing rod, preventing the components from coming off upwards. The fixing groove provides a bottom installation position. The limiting ring prevents the components from moving vertically, ensuring structural stability. The components are precisely limited and fixed from multiple directions, improving the efficiency and stability of the foundation pit support pile structure.

[0010] As a further description of the above technical solution:

[0011] The top of the outer wall of the fixing groove is provided with a groove, and a wear-resistant pad is fixedly connected to the top of the outer wall of the groove.

[0012] The above technical solution involves providing a groove on the top outer wall of the fixing groove, which enhances the connection and sealing of the structure. A wear-resistant pad is also fixed on the top outer wall of the groove to reduce wear and extend the equipment life.

[0013] As a further description of the above technical solution:

[0014] Each of the sliders has a fixed plate fixedly connected to the top of its outer wall, and the top of the fixed plate has multiple bolts threadedly connected to its outer wall.

[0015] The above technical solution involves connecting the top of the slider to a fixed plate, which enhances stability and facilitates assembly. The top of the fixed plate is threaded for connecting bolts, ensuring a robust structure and facilitating disassembly and maintenance.

[0016] As a further description of the above technical solution:

[0017] A funnel is slidably connected to the top of the outer wall of the fixed pile, and multiple bolts are threaded around the outer wall of the funnel.

[0018] The above technical solution involves connecting the funnel to the top of the fixed pile, with its outer wall secured by multiple bolts. This facilitates the pouring operation. The bolts not only ensure a stable connection between the funnel and the pile but also allow for horizontal adjustment to adapt to different work requirements and environments.

[0019] As a further description of the above technical solution:

[0020] A sealing ring is fixedly connected to the middle of the inner wall of the fixed pile, and multiple circular holes are opened on the top of the outer wall of the fixed pile.

[0021] The above technical solution involves installing a sealing ring in the middle of the inner wall of the fixed pile to improve the sealing effect, prevent fluid leakage, ensure connection stability and environmental protection, and use the circular hole at the top of the outer wall for connecting bolts and balancing the air pressure inside the wall. During construction, it helps concrete penetration and enhances the anchoring force.

[0022] As a further description of the above technical solution:

[0023] A rotating shaft is fixedly connected to one side of the inner wall of each of the multiple support rods, and bolts are threadedly connected to the front and rear sides of the outer wall of each of the multiple rotating shafts.

[0024] The above technical solution involves connecting the support rods via a rotating shaft, and adjusting the angle of the bolts to adapt to different foundation pit conditions, thereby enhancing the stability of the support structure.

[0025] As a further description of the above technical solution:

[0026] A support ring is fixedly connected to the bottom of the outer wall of the fixing groove, and a fixing ring is fixedly connected to the outer wall of the support ring at equal intervals.

[0027] The above technical solution provides additional support at the bottom of the fixing groove, while the fixing ring connects to the auxiliary support components, enhancing installation accuracy and stability.

[0028] This utility model has the following beneficial effects:

[0029] 1. In this utility model, in the foundation pit support structure, fixed piles serve as the foundation support, and the support rods connected to them are used to expand the support range. The rotating shaft causes the support rods and telescopic piles to rotate relative to each other, flexibly adjusting the extension angle of the telescopic piles. The limiting rod restricts the excessive extension and retraction of the telescopic piles. The adjusting plate further adjusts the support angle and position. The hydraulic push rod is connected to the top of the telescopic pile and adjusts the support force through the extension and retraction action. The slider is slidably connected to the adjusting plate to assist in adjusting the angle of the telescopic piles, enhancing the bearing capacity of the support piles, simplifying the construction process, reducing costs and environmental impact. By utilizing composite structures and high-strength materials, performance is maintained in complex geological conditions. The standardized and modular design simplifies construction, making it particularly suitable for narrow or complex terrain. Material and design optimization reduces costs and improves construction efficiency.

[0030] 2. In this utility model, the connecting mechanism is connected to the fixed pile through its internal structure to achieve quick connection and fixation. The docking groove is located in the middle of the inner wall of the fixed pile. The limiting plate can prevent the component from moving back and forth. The locking ring works in conjunction with the fixing rod. By rotating the fixing rod and locking it, the stability of the component is ensured. The fixing groove provides an installation position for the bottom, while the limiting ring prevents the component from moving in the vertical direction. Through multi-directional precise limiting and fixing, the connecting mechanism effectively improves the efficiency and stability of the foundation pit support pile structure. Attached Figure Description

[0031] Figure 1 This is a perspective view of a foundation pit support pile proposed in this utility model;

[0032] Figure 2 This is a front view of a foundation pit support pile proposed in this utility model;

[0033] Figure 3 This is a top view of a foundation pit support pile proposed in this utility model;

[0034] Figure 4 This is a partial structural diagram of a foundation pit support pile proposed in this utility model;

[0035] Figure 5 This is a split diagram of the connection mechanism of a foundation pit support pile proposed in this utility model.

[0036] Legend:

[0037] 1. Fixed pile; 2. Connecting mechanism; 201. Docking groove; 202. Limiting plate; 203. Engaging ring; 204. Fixed rod; 205. Limiting block; 206. Fixed groove; 207. Limiting ring; 3. Support rod; 4. Rotating shaft; 5. Telescopic pile; 6. Limiting rod; 7. Adjusting plate; 8. Support block; 9. Hydraulic push rod; 10. Sliding block; 11. Groove; 12. Wear-resistant pad; 13. Fixed plate; 14. Bolt one; 15. Funnel; 16. Bolt two; 17. Sealing ring; 18. Circular hole; 19. Rotating shaft; 20. Bolt three; 21. Support ring; 22. Fixed ring. Detailed Implementation

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0039] Reference Figure 1 , Figure 3 and Figure 4 An embodiment of this utility model provides: a foundation pit support pile, including a fixed pile 1, with support rods 3 fixedly connected around the outer wall of the fixed pile 1, a rotating shaft 4 rotatably connected to one side of the outer wall of each of the support rods 3, a telescopic pile 5 rotatably connected to the other side of the outer wall of the rotating shaft 4, a limit rod 6 rotatably connected to the middle of the outer wall of the telescopic pile 5, an adjusting plate 7 rotatably connected to the other end of the telescopic pile 5, support blocks 8 equidistantly fixedly connected to the inner wall of the adjusting plate 7, a hydraulic push rod 9 rotatably connected around the bottom of the fixed pile 1, one end of the hydraulic push rod 9 rotatably connected to the top of the outer wall of the telescopic pile 5, a slider 10 provided at the bottom of the outer wall of the hydraulic push rod 9, the slider 10 slidably connected to the middle of the inner wall of the adjusting plate 7, a connecting mechanism 2 fixedly connected to the top of the fixed pile 1, the connecting mechanism 2 being used to achieve quick locking and fixing, a funnel 15 slidably connected to the top of the outer wall of the fixed pile 1, and multiple bolts 16 threadedly connected around the outer wall of the funnel 15;

[0040] Specifically, in the foundation pit support structure, fixed pile 1 serves as the foundation support, and the connected support rod 3 is used to expand the support range. Rotating shaft 4 allows the support rod 3 and telescopic pile 5 to rotate relative to each other, flexibly adjusting the extension angle of the telescopic pile 5 to adapt to different foundation pit requirements. Limiting rod 6 restricts excessive extension and retraction of the telescopic pile 5, ensuring a safe working range. Adjusting plate 7 further adjusts the support angle and position, and its inner wall support block 8 provides multi-point support to enhance stability. Hydraulic push rod 9 is connected to the top of the telescopic pile 5, adjusting the support force through telescopic movement. The slider 10 is slidably connected to the adjusting plate 7 to assist in adjusting the angle of the telescopic pile 5 and ensure the smooth operation of the hydraulic push rod 9. The top of the fixed pile 1 is fixedly connected to the connecting mechanism 2, which is used to achieve quick locking and fixing. The funnel 15 is connected to the top of the outer wall of the fixed pile 1. Multiple bolts 16 are threaded around the outer wall of the funnel 15 to facilitate the convenience and efficiency of pouring. This not only ensures the stable connection between the funnel 15 and the fixed pile 1, but also allows the funnel 15 to be horizontally adjusted within a certain range by adjusting the bolts 16, thereby adapting to different working needs and environmental conditions.

[0041] Reference Figure 1 , Figure 2 and Figure 5 The connecting mechanism 2 includes a docking groove 201, which is fixedly connected to the middle of the inner wall of the fixed pile 1. Limiting plates 202 are fixedly connected to the front and rear sides of the outer wall of the docking groove 201. A locking ring 203 is fixedly connected to the top of the outer wall of the docking groove 201. A fixing rod 204 is rotatably connected to the left side of the outer wall of the locking ring 203. A limiting block 205 is threadedly connected to the front side of the outer wall of the fixing rod 204. A fixing groove 206 is fixedly connected to the bottom of the inner wall of the fixed pile 1. A limiting ring 207 is fixedly connected to the top of the outer wall of the fixing groove 206. A groove 11 is opened on the top of the outer wall of the fixing groove 206. A wear-resistant pad 12 is fixedly connected to the top of the outer wall of the groove 11. A fixing plate 13 is fixedly connected to the top of the outer wall of the multiple sliders 10. A multiple bolts 14 are threadedly connected to the top of the outer wall of the fixing plate 13.

[0042] Specifically, the connecting mechanism 2 connects to the fixed pile 1 through its internal structure, enabling quick connection and fixation. The docking groove 201 is located in the middle of the inner wall of the fixed pile 1, and the limiting plate 202 prevents the components from moving back and forth, ensuring precise docking. The locking ring 203 and the fixing rod 204 work together to rotate and lock the fixing rod 204, preventing the components from coming off upwards. The fixing groove 206 provides a bottom mounting position, and the limiting ring 207 prevents the components from moving vertically, ensuring structural stability. It precisely limits and fixes the components from multiple directions, improving the efficiency and stability of the foundation pit support pile structure. A groove 11 is opened on the top of the outer wall of the fixing groove 206. This groove 11 not only adds sealing to the connection of the structure, but also has a wear-resistant pad 12 fixedly connected to the top of the outer wall of the groove 11. The wear-resistant pad 12 effectively reduces wear and extends the service life of the equipment. Fixing plates 13 are fixedly connected to the top of the outer wall of multiple sliders 10. The fixing plates 13 not only stabilize the position of the sliders 10, but also provide convenience for subsequent assembly. Multiple bolts 14 are threadedly connected to the top of the outer wall of the fixing plates 13. The setting of these bolts 14 makes the entire structure more robust and also facilitates disassembly and maintenance.

[0043] Reference Figure 1 , Figure 2 and Figure 3 A sealing ring 17 is fixedly connected to the middle of the inner wall of the fixed pile 1. Multiple circular holes 18 are opened at the top of the outer wall of the fixed pile 1. A rotating shaft 19 is fixedly connected to the adjacent side of the inner wall of multiple support rods 3. Bolts 20 are threadedly connected to the front and rear sides of the outer wall of multiple rotating shafts 19. A support ring 21 is fixedly connected to the bottom of the outer wall of the fixed groove 206. A fixing ring 22 is fixedly connected to the outer wall of the support ring 21 at equal intervals.

[0044] Specifically, a sealing ring 17 is provided in the middle of the inner wall of the fixed pile 1 to enhance the sealing with the inserted component, prevent fluid leakage, ensure connection stability and environmental protection. The circular hole 18 at the top of the outer wall of the fixed pile 1 can be used to balance the connecting bolts and the air pressure of the inner wall, help concrete penetration during construction, and enhance the anchoring force. The support rod 3 is rotatably connected through the rotating shaft 19. Bolt 3 20 is used to adjust the relative angle of the support rod 3 to adapt to different foundation pit conditions and enhance the stability of the support structure. The support ring 21 at the bottom of the fixing groove 206 provides additional support force, while the fixing ring 22 is used to connect auxiliary support components to improve installation accuracy and stability.

[0045] Working Principle: In the foundation pit support pile structure, the fixed pile 1 serves as the foundation support structure. The support rods 3 connected around its outer wall extend the support range. When foundation pit support is required, the rotating shaft 4 allows the support rods 3 and the telescopic piles 5 to rotate relative to each other, thereby flexibly adjusting the extension angle of the telescopic piles 5 to adapt to foundation pits of different shapes and requirements. The limiting rod 6 is rotatably connected to the middle of the telescopic pile 5, limiting the excessive extension or retraction of the telescopic pile 5 and ensuring that it works within a safe and effective range. The adjusting plate 7 is rotatably connected to the other end of the telescopic pile 5 to further adjust the support angle and position. The support blocks 8 evenly distributed on the inner wall of the adjusting plate 7 can contact the foundation pit wall, providing multi-point support and enhancing stability. The hydraulic push rods 9 around the bottom of the fixed pile 1 are responsible for achieving support. The key component for force adjustment is the hydraulic push rod 9, one end of which is connected to the top of the outer wall of the telescopic pile 5. By telescoping, it changes the inclination angle and support height of the telescopic pile 5, thereby adjusting the support force of the entire support structure on the pit wall. The slider 10 at the bottom of the outer wall of the hydraulic push rod 9 is slidably connected to the middle of the inner wall of the adjusting plate 7. When the hydraulic push rod 9 telescops, the slider 10 slides in the adjusting plate 7 to assist in adjusting the angle change of the telescopic pile 5, while ensuring the smooth movement of the hydraulic push rod 9. This allows the entire support structure to be flexibly adjusted according to the actual situation of the pit, providing stable support, enhancing the bearing capacity of the support pile, reducing costs and environmental impact. Utilizing composite structures and high-strength materials, it is especially suitable for narrow or complex terrain. Material and design optimizations reduce costs and improve construction efficiency.

[0046] The connecting mechanism 2 surrounds the internal structure of the fixed pile 1, enabling quick connection and fixation. The docking groove 201 is fixed in the middle of the inner wall of the fixed pile 1 and is an important interface for docking. The limiting plates 202 on the front and rear sides of its outer wall prevent the docked parts from moving excessively in the front and rear directions, thus limiting the movement and ensuring the accuracy and stability of the docking. The locking ring 203 at the top of the outer wall of the docking groove 201 works in conjunction with the fixing rod 204 rotatably connected to the left side of its outer wall. When it is necessary to fix the docked parts, the fixing rod 204 is rotated to rotate around the locking ring 203 to the appropriate position, and then the fixing rod 204 is fixed by the front side of the outer wall of the fixing rod 204. The side threaded connection limiting block 205 locks the fixing rod 204, thereby fixing the component connected to the docking groove 201 at the top and preventing it from coming off upwards. The fixing groove 206 at the bottom of the inner wall of the fixing pile 1 provides the bottom installation position for the fixing pile 1. The limiting ring 207 at the top of its outer wall limits the component installed in the fixing groove 206 axially, preventing the component from moving excessively or coming off in the vertical direction, ensuring the stability of the entire structure in the vertical direction. The component connected to the fixing pile 1 is precisely limited and fixed from multiple directions, ensuring the efficiency and stability of the docking of the foundation pit support pile structure during use.

[0047] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A foundation pit support pile comprising a fixed pile (1), characterized in that: The outer wall of the fixed pile (1) is fixedly connected with a support rod (3), the outer wall of the support rod (3) is rotatably connected with a rotating shaft (4), the outer wall of the rotating shaft (4) is rotatably connected with a telescopic pile (5), the outer wall of the telescopic pile (5) is rotatably connected with a limiting rod (6) in the middle, the other end of the telescopic pile (5) is rotatably connected with an adjusting plate (7), the inner wall of the adjusting plate (7) is fixedly connected with a support block (8) at equal intervals, the bottom of the fixed pile (1) is rotatably connected with a hydraulic push rod (9), one end of the hydraulic push rod (9) is rotatably connected to the top of the outer wall of the telescopic pile (5), the outer wall of the hydraulic push rod (9) is provided with a sliding block (10), the sliding block (10) is slidably connected to the inner wall of the middle of the adjusting plate (7), the top of the fixed pile (1) is fixedly connected with a connecting mechanism (2), and the connecting mechanism (2) is used for realizing quick clamping and fixing.

2. The retaining pile according to claim 1, wherein: The connecting mechanism (2) comprises a butt joint groove (201), the butt joint groove (201) is fixedly connected to the inner wall of the middle of the fixed pile (1), the outer wall of the butt joint groove (201) is fixedly connected with a limiting plate (202) on the front and back sides, the outer wall of the butt joint groove (201) is fixedly connected with a clamping ring (203) on the top, the outer wall of the left side of the clamping ring (203) is rotatably connected with a fixed rod (204), the outer wall of the front side of the fixed rod (204) is threadedly connected with a limiting block (205), the inner wall of the bottom of the fixed pile (1) is fixedly connected with a fixed groove (206), and the outer wall of the top of the fixed groove (206) is fixedly connected with a limiting ring (207).

3. A retaining pile according to claim 2, wherein: The outer wall of the top of the fixed groove (206) is provided with a groove (11), and the outer wall of the top of the groove (11) is fixedly connected with a wear-resistant pad (12).

4. The retaining pile of claim 1, wherein: The outer wall of the top of the sliding block (10) is fixedly connected with a fixed plate (13), and the outer wall of the top of the fixed plate (13) is threadedly connected with a plurality of bolts (14).

5. The retaining pile of claim 1, wherein: The outer wall of the top of the fixed pile (1) is slidably connected with a funnel (15), and the outer wall of the funnel (15) is threadedly connected with a plurality of bolts (16) around.

6. The retaining pile of claim 1, wherein: The inner wall of the middle of the fixed pile (1) is fixedly connected with a sealing ring (17), and the outer wall of the top of the fixed pile (1) is provided with a plurality of circular holes (18).

7. The retaining pile of claim 1, wherein: The inner wall of the adjacent side of the support rod (3) is fixedly connected with a rotating shaft (19), and the outer wall of the front and back sides of the rotating shaft (19) is threadedly connected with a bolt (20).

8. The retaining pile of claim 2, wherein: The outer wall of the bottom of the fixed groove (206) is fixedly connected with a support ring (21), and the outer wall of the support ring (21) is fixedly connected with a fixed ring (22) at equal intervals.

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