Necking mechanism and necking device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WUXI LEAD INTELLIGENT EQUIP CO LTD
- Filing Date
- 2025-05-27
- Publication Date
- 2026-06-12
AI Technical Summary
Existing shrinking machines are prone to jamming and wear due to lack of lubrication during long-term use, which shortens the service life of the equipment and reduces the shrinking quality of battery steel shells.
A narrowing mechanism was designed, which uses an oil reservoir and a connecting hole between the fixed bushing and the movable bushing to inject lubricating oil through the oil injection hole, thereby achieving lubrication among the three components, avoiding jamming, and reducing wear.
It effectively avoids jamming, reduces wear, extends the service life of the equipment, and improves the quality of the battery steel casing's seam reduction.
Smart Images
Figure CN224346813U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery manufacturing equipment technology, specifically a necking mechanism and necking device. Background Technology
[0002] During the production of cylindrical batteries, the opening of the cylindrical battery steel casing needs to be narrowed, that is, the diameter of the opening of the battery steel casing needs to be reduced, in order to prevent the internal structure of the battery steel casing (such as the battery cell) from coming out of the opening.
[0003] However, the shrinking machine consists of multiple interlocking moving shafts. Due to lack of lubrication during long-term use, it is prone to jamming and excessive wear, which greatly shortens the service life of the shrinking machine and reduces the shrinking quality of the battery steel shell. Utility Model Content
[0004] Therefore, it is necessary to provide a necking mechanism and necking device that can fully lubricate the moving shafts, avoid jamming, greatly reduce wear, extend the service life of the equipment, and improve the necking quality of the battery steel shell to address the above problems.
[0005] A necking mechanism, comprising:
[0006] Fixed bushing;
[0007] A movable bushing is fitted inside the fixed bushing and is axially movable relative to the fixed bushing.
[0008] An intermediate shaft is sleeved inside the movable bushing and is axially movable relative to the movable bushing; and
[0009] A constriction die, comprising an inner die and an outer die respectively connected to the intermediate shaft and the movable bushing;
[0010] A first oil reservoir is formed between the fixed bushing and the movable bushing. The fixed bushing has an oil injection hole that connects the first oil reservoir to the outside of the fixed bushing. A second oil reservoir is formed between the movable bushing and the intermediate shaft. The movable bushing has a connecting hole that connects the first oil reservoir and the second oil reservoir.
[0011] In some embodiments, the oil injection hole penetrates both the inner and outer walls of the fixed bushing.
[0012] In some embodiments, the narrowing mechanism further includes an oil injection nozzle mounted on the oil injection hole.
[0013] In some embodiments, the outer wall of the movable bushing is recessed to form the first oil reservoir.
[0014] In some embodiments, the outer wall of the intermediate shaft is recessed to form the second oil reservoir.
[0015] In some embodiments, the oil injection hole is connected to the end of the first oil reservoir facing the constriction mold.
[0016] In some embodiments, the connecting hole is connected to the end of the first oil storage tank facing the narrowing mold, and the connecting hole is connected to the end of the second oil storage tank facing the narrowing mold.
[0017] In some embodiments, the fixed bushing is provided with a first clearance groove, which extends longitudinally along the axial direction of the fixed bushing.
[0018] The narrowing mechanism also includes a first follower, which is connected to the movable bushing and extends through the first clearance groove to the outside of the fixed bushing.
[0019] In some embodiments, the movable bushing is provided with a second clearance groove, which extends longitudinally along the axial direction of the movable bushing.
[0020] The narrowing mechanism also includes a second follower, which is connected to the intermediate shaft and extends through the second clearance groove and the first clearance groove to the outside of the fixed shaft sleeve.
[0021] In some embodiments, the end of the movable bushing opposite to the outer mold protrudes axially from the fixed bushing and the intermediate shaft;
[0022] The narrowing mechanism also includes a third follower, which is connected to the end of the movable bushing that is away from the outer mold.
[0023] A necking device includes a turntable, a material positioning component, and a necking mechanism as described in any of the above embodiments. The material positioning component is mounted on the turntable for loading material to be necked. A fixed bushing is mounted on the turntable. The inner mold and the outer mold are opposite to the material on the material positioning component in a direction parallel to the rotation axis of the turntable.
[0024] In some embodiments, the narrowing device further includes a cam assembly arranged around the turntable and capable of guiding and engaging with the first follower and the second follower.
[0025] The aforementioned necking mechanism and necking device, by opening a connecting hole on the movable bushing, connects the first oil reservoir and the second oil reservoir. This allows the lubricating oil in the first oil reservoir to enter the second oil reservoir through the connecting hole when lubricating oil is injected into the first oil reservoir through the oil injection hole. This achieves lubrication between the intermediate shaft, the movable bushing, and the fixed bushing, preventing jamming, greatly reducing wear on all three components, improving the service life of the intermediate shaft, the movable bushing, and the fixed bushing, and enhancing the necking processing quality of the battery steel shell. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the narrowing device in one embodiment of this application;
[0027] Figure 2 for Figure 1 A side view of the necking mechanism of the necking device shown;
[0028] Figure 3 for Figure 2 A cross-sectional view of the constriction mechanism shown;
[0029] Figure 4 for Figure 1 Front view of the necking mechanism of the necking device shown;
[0030] Figure 5 for Figure 4 The cross-sectional view of the constriction mechanism shown. Detailed Implementation
[0031] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0032] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0034] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0035] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0036] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.
[0037] Please see Figure 1This application provides a necking device, including a turntable 10, a necking mechanism 20, and a material positioning component 30. The turntable 10 is rotatably arranged around its own axis. The material positioning component 30 and the necking mechanism 20 are both mounted on the turntable 10, so that the turntable 10 can drive the material positioning component 30 and the necking mechanism 20 to rotate together. During the rotation of the turntable 10, the battery steel shell A to be necked is fed onto the material positioning component 30, and the necking mechanism 20 performs necking processing on the battery steel shell A on the material positioning component 30. After the necking processing is completed, the battery steel shell A on the material positioning component 30 is unloaded.
[0038] To improve production efficiency, multiple material positioning components 30 and multiple necking mechanisms 20 are used, with each material positioning component 30 and each necking mechanism 20 corresponding to one another. Each necking mechanism 20 and its corresponding material positioning component 30 are arranged at intervals along a direction parallel to the rotation axis of the turntable 10, so that each necking mechanism 20 can perform necking processing on the battery steel shell A on its corresponding material positioning component 30.
[0039] It should be noted that in this embodiment, the necking mechanism 20 performs necking processing on the battery steel casing A; that is, the material to be necked is the battery steel casing A. Of course, in other embodiments, the material to be necked can be other workpieces, and this is not limited here. For ease of understanding, this article uses the battery steel casing A as an example for illustration.
[0040] Please see Figure 2 and Figure 3 In the embodiments of this application, the necking mechanism 20 includes a fixed bushing 21, a movable bushing 22, an intermediate shaft 23, and a necking mold 24. The movable bushing 22 is sleeved inside the fixed bushing 21 and is axially movable relative to the fixed bushing 21. The intermediate shaft 23 is sleeved inside the movable bushing 22 and is axially movable relative to the movable bushing 22. That is, the fixed bushing 21, the movable bushing 22, and the intermediate shaft 23 are sequentially sleeved on each other from the outside to the inside, and their axial directions are consistent. The necking mold 24 includes an inner mold 243 and an outer mold 241. The inner mold 243 is connected to the intermediate shaft 23, so that the intermediate shaft 23 can drive the inner mold 243 to move axially. The outer mold 241 is connected to the movable bushing 22, so that the movable bushing 22 can drive the outer mold 241 to move axially.
[0041] Thus, in actual use, the intermediate shaft 23 can drive the inner mold 243 to move axially towards the battery steel shell A on the material positioning component 30, so that the inner mold 243 enters the battery steel shell A through the opening; the movable bushing 22 can drive the outer mold 241 to move axially towards the battery steel shell A on the material positioning component 30, so that the outer mold 241 is fitted on the outside of the end of the battery steel shell A with the opening, thereby causing the shell wall of the battery steel shell A to be squeezed inward by the outer mold 241 and deform inward (i.e., shrinking). Since the inner mold 243 is inside the battery steel shell A when the outer mold 241 shrinks the shell A, the shell wall of the battery steel shell A is confined between the inner mold 243 and the outer mold 241, which greatly reduces the risk of wrinkles and helps to improve the shrinking quality.
[0042] In a specific embodiment, a first oil reservoir B1 is formed between the fixed bushing 21 and the movable bushing 22. The fixed bushing 21 has an oil injection hole 211 that connects the first oil reservoir B1 with the outside of the fixed bushing 21. Lubricating oil can be injected into the first oil reservoir B1 through the oil injection hole 211, and the lubricating oil in the first oil reservoir B1 can be used to lubricate between the fixed bushing 21 and the movable bushing 22, so as to avoid jamming between the fixed bushing 21 and the movable bushing 22 and greatly reduce the wear of the fixed bushing 21 and the movable bushing 22.
[0043] A second oil reservoir B2 is formed between the movable bushing 22 and the intermediate shaft 23. The movable bushing 22 has a connecting hole 221 that connects the first oil reservoir B1 and the second oil reservoir B2. Thus, the lubricating oil injected into the first oil reservoir B1 can enter the second oil reservoir B2 through the connecting hole 221. The lubricating oil in the second oil reservoir B2 is then used to lubricate the movable bushing 22 and the intermediate shaft 23, preventing jamming between the movable bushing 22 and the intermediate shaft 23 and greatly reducing the wear of the movable bushing 22 and the intermediate shaft 23.
[0044] Thus, by opening a connecting hole 221 on the movable bushing 22, the first oil reservoir B1 and the second oil reservoir B2 are connected through the connecting hole 221. This allows the lubricating oil in the first oil reservoir B1 to enter the second oil reservoir B2 through the connecting hole 221 when lubricating oil is injected into the first oil reservoir B1 through the oil injection hole 211. This achieves lubrication between the intermediate shaft 23, the movable bushing 22, and the fixed bushing 21, preventing jamming, greatly reducing wear on all three components, improving the service life of the intermediate shaft 23, the movable bushing 22, and the fixed bushing 21, and improving the quality of the necking process of the battery steel shell A.
[0045] Specifically, in this embodiment, the oil injection hole 211 penetrates both the inner and outer walls of the fixed bushing 21. That is, the oil injection hole 211 is located on the side wall of the fixed bushing 21, rather than at its top. If the oil injection hole 211 were located at the top of the fixed bushing 21, the space at the top of the fixed bushing 21 would be limited due to the constriction die 24 being positioned at the tops of the movable bushing 22 and the intermediate shaft 23, making oil injection difficult. Therefore, in this application, the oil injection hole 211 is positioned on the side wall of the fixed bushing 21, significantly reducing the difficulty of oil injection.
[0046] In a specific embodiment, the narrowing mechanism 20 further includes an oil injection nozzle 25, which is installed in the oil injection hole 211, allowing lubricating oil to be injected into the first oil reservoir B1 through the oil injection nozzle 25. When not injecting oil, the oil injection nozzle 25 is used to block the oil injection hole 211 to prevent lubricating oil from leaking out of the first oil reservoir B1.
[0047] In a specific embodiment, the inner mold 243 and outer mold 241 of the constriction mold 24 are arranged at the top of the intermediate shaft 23 and the movable bushing 22. The oil injection hole 211 is connected to the end of the first oil reservoir B1 facing the constriction mold 24, that is, the oil injection hole 211 is connected to the top of the first oil reservoir B1, which makes the position of the oil injection hole 211 higher and greatly reduces the risk of oil leakage from the oil injection hole 211.
[0048] In a specific embodiment, the connecting hole 221 is connected to the end of the first oil reservoir B1 facing the reducing mold 24, and also to the end of the second oil reservoir B2 facing the reducing mold 24. That is, the connecting hole 221 is located at the top of the first oil reservoir B1 and the second oil reservoir B2. During oil filling, lubricating oil first enters the first oil reservoir B1. After the first oil reservoir B1 is full, the lubricating oil in the first oil reservoir B1 overflows into the second oil reservoir B2 through the connecting hole 221 until the second oil reservoir B2 is full. Thus, by arranging the connecting hole 221 at the top of the first oil reservoir B1 and the second oil reservoir B2, it is ensured that the amount of lubricating oil in the first oil reservoir B1 and the second oil reservoir B2 is sufficient, further improving the lubrication effect.
[0049] In a specific embodiment, the outer wall of the movable bushing 22 is recessed to form the aforementioned first oil reservoir B1. That is, the first oil reservoir B1 is formed on the outer wall of the movable bushing 22, which helps reduce machining difficulty. Of course, in other embodiments, the first oil reservoir B1 can also be formed on the inner wall of the fixed bushing 21. In still other embodiments, grooves can be formed on both the inner wall of the fixed bushing 21 and the outer wall of the movable bushing 22, so that the grooves on the inner wall of the fixed bushing 21 and the grooves on the outer wall of the movable bushing 22 together form the first oil reservoir B1; this is not limited here.
[0050] In a specific embodiment, the outer wall of the intermediate shaft 23 is recessed to form the aforementioned second oil reservoir B2. That is, placing the second oil reservoir B2 on the outer wall of the intermediate shaft 23 helps reduce machining difficulty. Of course, in other embodiments, the second oil reservoir B2 can also be formed on the inner wall of the movable bushing 22. In still other embodiments, grooves can be formed on both the inner wall of the movable bushing 22 and the outer wall of the intermediate shaft 23, so that the grooves on the inner wall of the movable bushing 22 and the grooves on the outer wall of the intermediate shaft 23 combine to form the second oil reservoir B2; this is not limited to any particular embodiment.
[0051] Please see Figure 4 and Figure 5 In the embodiments of this application, the fixed bushing 21 is provided with a first clearance groove 213, which penetrates the inner wall and outer wall of the fixed bushing 21 and extends longitudinally along the axial direction of the fixed bushing 21, that is, the first clearance groove 213 is a long strip extending longitudinally along the axial direction of the fixed bushing 21. The narrowing mechanism 20 also includes a first follower 26. The first follower 26 is connected to the movable bushing 22 and passes through the first clearance groove 213 to the outer side of the fixed bushing 21.
[0052] The necking device also includes a cam assembly 40 (see Figure 1 The cam assembly 40 is arranged around the turntable 10 and can be guided and engaged with the first follower 26. Thus, as the turntable 10 drives the narrowing mechanism 20 to rotate, it can drive the first follower 26 to contact the cam assembly 40, thereby driving the first follower 26 to move axially in the movable bushing 22 under the guidance of the cam assembly 40, thereby driving the outer mold 241 to move closer to or away from the battery steel shell A on the material positioning member 30.
[0053] It should be noted that by using the cam assembly 40 in conjunction with the first follower 26, the rotational motion of the turntable 10 is converted into the axial movement of the outer mold 241 along the movable bushing 22. Compared with the scheme of using a linear drive to drive the movable bushing 22 to move axially, this method is beneficial to reducing equipment costs.
[0054] Furthermore, the first follower 26 can be a roller. During the rotation of the narrowing mechanism 20 driven by the turntable 10, the first follower 26 can roll with the cam assembly 40, that is, the first follower 26 rolls along the cam assembly 40, thereby using the guiding effect of the cam assembly 40 to drive the first follower 26, the movable bushing 22 and the outer mold 241 to generate axial displacement.
[0055] Specifically, in this embodiment, the movable bushing 22 has a second clearance groove 223, which penetrates the inner and outer walls of the movable bushing 22 and extends longitudinally along the axial direction of the movable bushing 22, i.e., the second clearance groove 223 is a long strip extending longitudinally along the axial direction of the movable bushing 22. The narrowing mechanism 20 also includes a second follower 27, which is connected to the intermediate shaft 23 and extends through the second clearance groove 223 and the first clearance groove 213 to the outer side of the fixed bushing 21. During the rotation of the turntable 10, the second follower 27 can be driven to contact the cam assembly 40, thereby driving the second follower 27 to move axially along the intermediate shaft 23 under the guidance of the cam assembly 40, thereby causing the inner mold 243 to move closer to or away from the battery steel shell A on the material positioning member 30.
[0056] It should be noted that by using the cam assembly 40 in conjunction with the second follower 27, the rotational motion of the turntable 10 is converted into the axial movement of the inner mold 243 along the intermediate shaft 23. Compared with the scheme of using a linear drive to drive the intermediate shaft 23 to move axially, this method is beneficial to reducing equipment costs.
[0057] Furthermore, the second follower 27 can be a roller. During the rotation of the narrowing mechanism 20 driven by the turntable 10, the second follower 27 can roll with the cam assembly 40, that is, the second follower 27 rolls along the cam assembly 40, thereby using the guiding effect of the cam assembly 40 to drive the second follower 27, the intermediate shaft 23 and the inner mold 243 to generate axial displacement.
[0058] In a specific embodiment, the end of the movable bushing 22 that is away from the outer mold 241 (i.e., as shown in the example) Figure 5 The bottom end of the movable shaft (shown) protrudes axially from the fixed bushing 21 and the intermediate shaft 23. The narrowing mechanism 20 also includes a third follower 28, which is mounted on the end of the movable bushing 22 opposite to the outer mold 241. During the rotation of the narrowing mechanism 20 driven by the turntable 10, the third follower 28 can be supported on the cam assembly 40, thereby supporting the movable bushing 22 and the intermediate shaft 23.
[0059] Furthermore, the third follower 28 can be a roller. During the rotation of the narrowing mechanism 20 driven by the turntable 10, the third follower 28 can be supported on the cam assembly 40 and roll along the cam assembly 40.
[0060] It should be noted that the movement of the movable sleeve 22 and the intermediate shaft 23 along the axis is not limited to using the cam assembly 40. In other embodiments, two linear drives may be provided. The movable sleeve 22 is connected to the drive end of one of the linear drives, thereby driving the movable sleeve 22 to move axially using the linear drive. The intermediate shaft 23 is connected to the drive end of the other linear drive, thereby driving the intermediate shaft 23 to move axially using the linear drive. Optionally, the linear drive may be a cylinder, an electric cylinder, etc.
[0061] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0062] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A necking mechanism, characterized in that, include: Fixed bushing (21); The movable bushing (22) is fitted inside the fixed bushing (21) and is axially movable relative to the fixed bushing (21); An intermediate shaft (23) is sleeved inside the movable bushing (22) and is axially movable relative to the movable bushing (22); and The constriction mold (24) includes an inner mold (243) and an outer mold (241) respectively connected to the intermediate shaft (23) and the movable bushing (22); A first oil reservoir (B1) is formed between the fixed bushing (21) and the movable bushing (22). The fixed bushing (21) has an oil injection hole (211) that connects the first oil reservoir (B1) to the outside of the fixed bushing (21). A second oil reservoir (B2) is formed between the movable bushing (22) and the intermediate shaft (23). The movable bushing (22) has a connecting hole (221) that connects the first oil reservoir (B1) and the second oil reservoir (B2).
2. The narrowing mechanism according to claim 1, characterized in that, The oil injection hole (211) penetrates the inner and outer walls of the fixed bushing (21).
3. The narrowing mechanism according to claim 1, characterized in that, The narrowing mechanism (20) also includes an oil injection nozzle (25), which is installed in the oil injection hole (211).
4. The narrowing mechanism according to claim 1, characterized in that, The outer wall of the movable bushing (22) is recessed to form the first oil reservoir (B1).
5. The narrowing mechanism according to claim 1, characterized in that, The outer wall of the intermediate shaft (23) is recessed to form the second oil storage tank (B2).
6. The narrowing mechanism according to claim 1, characterized in that, The oil injection hole (211) is connected to the end of the first oil storage tank (B1) facing the constriction mold (24).
7. The narrowing mechanism according to claim 1, characterized in that, The connecting hole (221) is connected to one end of the first oil storage tank (B1) facing the constriction mold (24), and the connecting hole (221) is connected to one end of the second oil storage tank (B2) facing the constriction mold (24).
8. The narrowing mechanism according to claim 1, characterized in that, The fixed bushing (21) is provided with a first clearance groove (213), which extends longitudinally along the axial direction of the fixed bushing (21). The narrowing mechanism (20) further includes a first follower (26), which is connected to the movable bushing (22) and extends through the first clearance groove (213) to the outside of the fixed bushing (21).
9. The narrowing mechanism according to claim 8, characterized in that, The movable bushing (22) is provided with a second clearance groove (223), which extends longitudinally along the axial direction of the movable bushing (22); The narrowing mechanism (20) further includes a second follower (27), which is connected to the intermediate shaft (23) and extends through the second clearance groove (223) and the first clearance groove (213) to the outside of the fixed bushing (21).
10. The narrowing mechanism according to claim 1, characterized in that, The end of the movable bushing (22) facing away from the outer mold (241) protrudes axially from the fixed bushing (21) and the intermediate shaft (23). The narrowing mechanism (20) also includes a third follower (28), which is connected to the end of the movable bushing (22) away from the outer mold (241).
11. A necking device, characterized in that, The device includes a turntable (10), a material positioning component (30), and a necking mechanism (20) as described in any one of claims 1 to 10. The material positioning component (30) is mounted on the turntable (10) for loading the material to be necked. The fixed bushing (21) is mounted on the turntable (10). The inner mold (243) and the outer mold (241) are opposite to the material on the material positioning component (30) in a direction parallel to the rotation axis of the turntable (10).
12. The necking device according to claim 11, characterized in that, The narrowing device also includes a cam assembly (40) arranged around the turntable (10) and capable of guiding and cooperating with the first follower (26) and the second follower (27).