Soil retaining and scraping mechanism and soil preparation machine tool
By designing an adjustable buffer mechanism on the ground leveling machine, the elastic buffering force of the soil retaining scraper plate is enhanced, which solves the problem of insufficient spring pressure in the existing technology, achieves better soil crushing and surface leveling effects, and adapts to various soil conditions and obstacle impacts.
Patent Information
- Application Number
- CN202422652272.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2025-10-17
- Estimated Expiration
- 2034-10-31
AI Technical Summary
The soil retaining and scraping mechanism of existing land preparation equipment has weak soil crushing ability due to insufficient spring pressure, the soil is not easily fully crushed, the surface flatness is poor, it is difficult to adapt to different soil conditions and farming needs, and it is easy to be damaged when encountering obstacles.
An adjustable buffer mechanism is designed, including a soil retaining scraper plate, a telescopic adjustment member and a buffer member. By adjusting the upper and lower elastic members, an elastic buffer force is provided to enhance the downward pressure and adaptability of the soil retaining scraper plate to adapt to different soil conditions and obstacle impacts.
The soil crushing capacity and surface flatness of the retaining and scraping mechanism are improved, the risk of machine damage is reduced, and good land preparation effects can be maintained under different soil conditions.
Smart Images
Figure CN223437352U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to ploughing and soil preparation equipment technical field, concretely relates to a soil retaining and scraping mechanism and a soil preparation machine. BACKGROUND
[0002] The soil preparation machine can level the ground, eliminate unevenness and pit phenomenon, improve the flatness of farmland, and is beneficial to subsequent seeding, irrigation, fertilization and other mechanized operations. After the treatment of the soil preparation machine, the physical and chemical properties of the soil are improved, providing a better growth environment for crop growth. Good soil conditions and growth environment are conducive to the growth and development of crops, thereby improving the yield and quality of crops.
[0003] The soil retaining and scraping mechanism is mainly used to limit the soil brought up by the high-speed rotating blade of the soil preparation machine, prevent it from splashing out of the machine, and improve the soil breaking rate of the soil preparation machine. At the same time, the soil retaining and scraping mechanism drags, scrapes and arranges the uneven ground to make it flat, providing good soil conditions for subsequent operations. In addition to leveling the soil, the soil retaining and scraping mechanism also has the functions of breaking and compacting the soil. During the dragging and scraping process, the soil retaining and scraping mechanism further breaks and compacts the soil, making the soil particles finer and more compact, which is conducive to the growth of crop roots and the retention of soil moisture. The leveled soil helps the operation of the seeding machine, reduces the waste of seeds, and improves the uniformity and consistency of seeding. After leveling the soil with the drag plate, the seeding machine can run more smoothly on the field, reducing the jamming and missed planting caused by uneven soil, thereby improving the seeding efficiency. The soil retaining and scraping mechanism of the soil preparation machine has multiple functions such as adjusting the plowing depth, leveling the soil, improving the seeding efficiency, breaking and compacting the soil, and removing straw and weeds, etc. It is one of the important auxiliary components of the soil preparation machine, and has important significance for improving the agricultural production efficiency and crop yield.
[0004] The conventional land leveling tool part is provided with a scraper and the like, but due to its light weight and simple structure, the spring pressure is insufficient, the buffer stroke is small, and the like, and thus the following problems exist: the small spring pressure means that the pressure of the scraper on the soil is insufficient, which can result in the soil breaking ability of the rotary cultivator being weakened during the cultivation process, the soil can not be broken sufficiently, large soil clumps are formed, and the cultivation quality is affected; the small spring pressure of the scraper also results in the strength of the scraper being weakened when the scraper is used to level the ground, which can result in the ground not being leveled sufficiently, leaving gullies, depressions and the like, and the effect of compacting the soil being poor. At the same time, due to the small spring stroke, the adjustable range is limited, and it is difficult to adapt to changes in different soil conditions and cultivation requirements, and when uneven ground or a large resistance is encountered, due to the limited spring stroke, the buffer and adjustment cannot be effectively performed, and the operation effect is poor.
[0005] In order to solve these problems, the utility model discloses a kind of buffer function's earth retaining scraping mechanism and the land leveling tool of application of the mechanism, by optimizing structure design, convenient adjustment and the like Measure to improve the effect of earth retaining scraping structure. Utility model contents
[0006] The technical problem to be solved by the utility model is to provide an earth retaining scraping mechanism, which has a buffering function and can adjust the buffering range, thereby improving the effect of earth retaining scraping during land leveling.
[0007] To solve the above technical problems, the utility model adopts the following technical scheme: an earth retaining scraping mechanism, comprising an earth retaining scraping plate and an adjustable buffer mechanism, the earth retaining scraping plate is provided with a first turnover connecting part and a buffer connecting part, the adjustable buffer mechanism comprises a telescopic adjusting part and a buffer part, the fixed part of the telescopic adjusting part is provided with a second turnover connecting part, the telescopic part of the telescopic adjusting part is provided with an adjustable guide part, the adjustable guide part is provided with a main guide channel, the guide direction of the main guide channel is parallel to the telescopic direction of the telescopic adjusting part, the buffer part passes through the main guide channel and moves relative to the adjustable guide part, the buffer part is provided with an upper elastic part and a lower elastic part above and below the adjustable guide part respectively, and is provided with an upper stop part and a lower stop part above and below the upper elastic part and the lower elastic part respectively, the bottom end of the buffer part is rotatably connected with the buffer connecting part, and the earth retaining scraping plate is rotatable relative to the first turnover connecting part to drive the buffer part to move along the main guide channel. When used on a land leveling tool, the adjustable buffer mechanism not only provides a buffering force for the earth retaining scraping plate, so that the earth retaining scraping plate can elastically swing relative to the land leveling tool, but also the buffering effect of the adjustable buffer mechanism can be adjusted, so as to adaptively adjust according to the environment or the aging degree of the parts used by the land leveling tool, so that the earth retaining scraping plate can maintain the best use state.
[0008] As a preferred scheme of the utility model, the upper pin hole is arranged above the adjustable guide piece on the buffer piece, an upper blocking pin is arranged in the upper pin hole, and the upper blocking pin is an upper blocking piece.
[0009] As a preferred scheme of the utility model, at least two upper pin holes are arranged on the buffer piece along the length direction above the adjustable guide piece, and the upper blocking pin is detachably arranged in one of the upper pin holes; at least two lower pin holes are arranged on the buffer piece along the length direction below the adjustable guide piece, and the lower blocking pin is detachably arranged in one of the lower pin holes. The upper pin hole and the lower pin hole are arranged as multiple, and the position of the upper pin hole and the lower pin hole can be adjusted to realize the pre-adjustment of the upper elastic piece and the lower elastic piece.
[0010] As a preferred scheme of the utility model, the buffer piece is a round rod, and the upper elastic piece and the lower elastic piece are springs sleeved on the buffer piece.
[0011] As a preferred scheme of the utility model, a blocking ring is arranged between the upper elastic piece and the upper blocking pin and between the lower elastic piece and the lower blocking pin on the buffer piece. The blocking ring is arranged between the upper elastic piece and the upper blocking pin and between the lower elastic piece and the lower blocking pin, which is beneficial to improving the stability of the installation of the upper elastic piece and the lower elastic piece and reducing the deformation risk of the upper blocking pin and the lower blocking pin.
[0012] As a preferred scheme of the utility model, the fixing part of the telescopic adjusting piece is provided with an auxiliary guide piece, the auxiliary guide piece is provided with an auxiliary guide channel, the auxiliary guide channel is coaxial with the main guide channel, the buffer piece passes through the auxiliary guide channel, and a gap is reserved between the auxiliary guide piece and the upper elastic piece. The buffer piece passes through the main guide channel and the auxiliary guide channel at the same time, which further ensures the reverse movement of the buffer piece and avoids the influence of the deviation of the movement direction of the buffer piece on the buffering function of the soil retaining and scraping plate.
[0013] As a preferred scheme of the utility model, the adjustable guide piece and the auxiliary guide piece are guide plates provided with guide holes on the plate surface, and the buffer piece passes through the guide holes of the guide plates.
[0014] As a preferred scheme of the utility model, the top of the soil retaining and scraping plate is provided with a first turnover connecting part, and the back of the soil retaining and scraping plate is provided with a buffer connecting part.
[0015] Based on the same concept, the utility model also provides a land preparation machine tool which comprises a machine tool main body, a tamping mechanism, a soil retaining and scraping mechanism, a first turnover connecting part, a second turnover connecting part, a telescopic adjusting piece and a buffer piece. The first turnover connecting part is connected with the machine tool main body and the soil retaining and scraping plate is turned relative to the connection of the machine tool main body, the second turnover connecting part is connected with the tamping mechanism mounting frame and the telescopic adjusting piece is rotated relative to the connection of the tamping mechanism. The land preparation machine tool is provided with the soil retaining and scraping mechanism with the buffering function, which is beneficial to improving the land preparation effect on the land.
[0016] As a preferred scheme of the utility model, the back of the earth retaining and scraping plate is provided with a connecting lug, the buffer member is provided with a connecting hole, and the connecting lug is connected with the buffer member through a connecting pin and the buffer member rotates relative to the connecting lug.
[0017] Compared with the prior art, the utility model has the beneficial effects that the adjustable buffer mechanism buffers the earth scraping plate, the earth scraping plate has strong pressing force, strong soil crushing capacity and good earth leveling effect, the buffering effect of the adjustable buffer mechanism can be adjusted, the earth scraping plate can adapt to various soil adjustment and various plowing requirements, and good land leveling effect can be achieved on uneven ground or when encountering large resistance, and good soil conditions are provided for subsequent operation. BRIEF DESCRIPTION OF DRAWINGS
[0018] In order to more clearly illustrate the technical schemes in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings can be obtained by those skilled in the art without creative labor on the premise of the drawings.
[0019] Figure 1 It is a structural schematic view of the earth retaining and scraping mechanism.
[0020] Figure 2 It is a structural schematic view of the land leveling machine.
[0021] In the drawing: 1, earth retaining and scraping plate, 11, first overturning connecting part, 12, buffer connecting part, 2, adjustable buffer mechanism, 21, telescopic adjusting part, 22, buffer member, 23, second overturning connecting part, 24, adjustable guide part, 25, upper elastic part, 26, lower elastic part, 27, auxiliary guide part, 3, machine body, 4, compacting mechanism. DETAILED DESCRIPTION
[0022] The technical schemes in the embodiments of the utility model will be clearly and completely described in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only some embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.
[0023] Embodiment 1
[0024] Please refer to Figure 1The soil retaining and scraping mechanism comprises a soil retaining and scraping plate 1 and an adjustable buffer mechanism 2. The soil retaining and scraping plate 1 is provided with a first overturning connecting part 11 and a buffer connecting part 12. The first overturning connecting part 11 is in the form of a connecting lug or the like and is used for connecting with the land preparation tool. The first overturning connecting part 11 is arranged at the top of the soil retaining and scraping plate 1. The buffer connecting part 12 is used for connecting with the adjustable buffer mechanism 2 and is arranged at the lower back of the soil retaining and scraping plate 1. When the soil retaining and scraping mechanism is installed on the land preparation tool and used, the soil retaining and scraping plate 1 is overturned relative to the connecting part of the land preparation tool. The adjustable buffer mechanism 2 is installed on the land preparation tool and the acting part thereof is connected with the buffer connecting part 12 of the soil retaining and scraping plate 1. During the land preparation process, the soil retaining and scraping plate 1 interacts with the soil, which causes the soil retaining and scraping plate 1 to be overturned relative to the land preparation tool. The elastic part of the adjustable buffer mechanism 2 is deformed, so that the soil retaining and scraping plate 1 has a buffering function.
[0025] The adjustable buffer mechanism 2 comprises a telescopic adjusting part 21 and a buffer part 22. The telescopic adjusting part 21 is in the form of a telescopic power part such as an oil cylinder or a hand-operated jack. The fixed part of the telescopic adjusting part 21 is provided with a second overturning connecting part 23. The second overturning connecting part 23 is used for connecting with the land preparation tool. The second overturning connecting part 23 can be a connecting ring or a connecting cylinder which is fixed on the fixed part of the telescopic adjusting part 21 and is suitable for a pin shaft to pass through. After the second overturning connecting part 23 is connected with the land preparation tool through the pin shaft, the telescopic adjusting part 21 can rotate relative to the connecting part of the land preparation tool. The telescopic part of the telescopic adjusting part 21 is provided with an adjustable guide part 24. The adjustable guide part 24 is provided with a main guide channel. The guide direction of the main guide channel is parallel to the telescopic direction of the telescopic adjusting part 21. The buffer part 22 is arranged on the adjustable guide part 24. The buffer part 22 passes through the main guide channel and can move along the main guide channel relative to the adjustable guide part 24. The buffer part 22 is provided with an upper elastic part 25 above the adjustable guide part 24. The buffer part 22 is provided with an upper stop part above the upper elastic part 25. The buffer part 22 is provided with a lower elastic part 26 below the adjustable guide part 24. The buffer part 22 is provided with a lower stop part below the lower elastic part 26. The elastic forces of the upper elastic part 25 and the lower elastic part 26 act on the buffer part 22. The movement of the buffer part 22 along the main guide channel causes the elastic deformation of the upper elastic part 25 and the lower elastic part 26.
[0026] When the soil retaining and scraping plate 1 is overturned relative to the first overturning connecting part 11, the buffer part 22 is moved along the main guide channel, which causes the elastic deformation of the upper elastic part 25 and the lower elastic part 26. The two elastic parts provide the buffering force for the soil retaining and scraping plate 1. The telescopic movement of the telescopic adjusting part 21 can drive the adjustable guide part 24 to move, and then drive the buffer part 22 to move. The pre-tightening force of the upper elastic part 25 and the lower elastic part 26 changes, so that the buffering effect of the soil retaining and scraping plate 1 is adjusted.
[0027] The soil blocking and scraping mechanism is used on the land preparation machine tool, the soil blocking and scraping plate 1 can scrape the soil, when the machine tool encounters obstacles such as stones and roots, the adjustable buffer mechanism 2 can reduce the impact of the obstacles on the land preparation machine tool, reduce the damage risk of the land preparation machine tool, the elastic force state of the upper elastic element 25 and the lower elastic element 26 can be adjusted through the telescopic adjusting element 21, so that the buffering effect on the soil blocking and scraping plate 1 is adjusted.
[0028] Specifically, the upper buffer element 22 is provided with an upper pin hole above the adjustable guide element 24, an upper blocking pin is arranged in the upper pin hole, the upper blocking pin is an upper blocking element, the upper end of the upper buffer element 22 is in contact with the upper blocking element, and the lower end is in contact with the buffer element 22, preferably, the upper buffer element 22 is provided with at least two upper pin holes along the length direction above the adjustable guide element 24, the upper blocking pin is detachably arranged in one of the upper pin holes, and the pre-tightening force of the upper elastic element 25 can be adjusted by adjusting the mounting position of the upper blocking pin; the buffer element 22 is provided with a lower pin hole below the adjustable guide element 24, a lower blocking pin is arranged in the lower pin hole, the lower blocking pin is a lower blocking element, the upper end of the lower buffer element 22 is in contact with the buffer element 22, and the lower end is in contact with the lower blocking pin, preferably, the buffer element 22 is provided with at least two lower pin holes along the length direction below the adjustable guide element 24, the lower blocking pin is detachably arranged in one of the lower pin holes, and the pre-tightening force of the lower elastic element 26 can be adjusted by adjusting the mounting position of the lower blocking pin.
[0029] The buffer element 22 is preferably a round rod, the upper elastic element 25 and the lower elastic element 26 are springs sleeved on the buffer element 22, and the buffer element 22 is provided with a blocking ring between the upper elastic element 25 and the upper blocking pin and between the lower elastic element 26 and the lower blocking pin.
[0030] As an optional embodiment, the fixed part of the telescopic adjusting element 21 is provided with an auxiliary guide element 27, the auxiliary guide element 27 is provided with an auxiliary guide channel, the auxiliary guide channel is coaxial with the main guide channel, the buffer element 22 passes through the main guide channel and the auxiliary guide channel, the moving direction of the buffer element 22 is parallel to the telescopic direction of the telescopic adjusting element 21, so that the stability of the buffering effect is ensured, and a gap is reserved between the auxiliary guide element 27 and the upper elastic element 25, so that the auxiliary guide element 27 does not affect the upper elastic element 25.
[0031] The adjustable guide element 24 and the auxiliary guide element 27 can be guide plates, the guide plates are provided with guide holes, and the buffer element 22 simultaneously passes through the guide holes of the two guide plates, so that the moving direction of the buffer element 22 is limited.
[0032] Embodiment 2
[0033] Please refer to Figure 1 and Figure 2The land preparation machine comprises a machine body 3, a compacting mechanism 4, and a soil blocking and scraping mechanism, the soil blocking and scraping mechanism is the soil blocking and scraping mechanism described in Embodiment 1, the first overturning connecting part 11 of the soil blocking and scraping plate 1 is connected with the machine body 3 and the soil blocking and scraping plate 1 can overturn relative to the connecting part of the machine body 3, and the second overturning connecting part 23 of the adjustable buffer mechanism 2 is connected with the mounting frame of the compacting mechanism 4 and the telescopic adjusting part 21 can rotate relative to the connecting part of the compacting mechanism 4.
[0034] The back of the soil blocking and scraping plate 1 is provided with a connecting lug, the connecting lug is the buffer connecting part 12, the bottom end of the buffer part 22 is provided with a connecting hole, a connecting pin is arranged in the connecting hole, and the connecting pin is connected with the connecting lug, so that the buffer part 22 is connected with the connecting lug and rotates relative to the connecting lug.
[0035] During the operation of the land preparation machine, the rotating blade in front of the soil blocking and scraping plate 1 throws the soil blocks to the soil blocking and scraping plate 1 at a high speed, part of the larger soil blocks are crushed in the process of collision, and part of the soil blocks that are not completely crushed are gathered at the bottom of the soil blocking and scraping plate 1, the rotating blade crushes the soil blocks for multiple times, so that the effect of crushing the soil is achieved, and in this process, the upper elastic part 25 and the lower elastic part 26 of the adjustable buffer mechanism 2 play a buffering role to reduce the vibration in the operation process; during the operation, due to the uneven ground, the soil blocking and scraping plate 1 plays a role of ground profiling due to the elastic force of the upper elastic part 25 and the lower elastic part 26 of the adjustable buffer mechanism 2, drags, scrapes and arranges the uneven ground, so that the ground becomes flat, and good soil conditions are provided for subsequent operation.
[0036] The telescopic adjusting part 21 is rotatably arranged on the mounting frame of the compacting mechanism 4, and when the soil blocking and scraping plate 1 is overturned upward, the rising force is transmitted to the compacting mechanism 4 through the lower elastic part 26 and the telescopic adjusting part 21, and because the compacting mechanism 4 has a large weight, the resistance is large when the soil blocking and scraping plate 1 is overturned upward, so the soil blocking and scraping plate 1 is not easy to overturn upward, thereby having good effects of soil blocking, scraping, soil crushing and compaction.
[0037] In the embodiment, the soil blocking and scraping mechanism with the buffering function can more effectively control the soil scraping process, reduce the unevenness of the soil surface, and improve the flatness of the land preparation, in the operation process, the machine may encounter obstacles such as stones and roots, the adjustable buffer mechanism 2 can reduce the impact of the obstacles on the soil blocking and scraping plate 1, reduce the damage risk of the machine, and the soil blocking and scraping mechanism with the buffering function can better adapt to different soil conditions of hardness, humidity and viscosity, and ensure that good land preparation effects can be achieved in various soil environments.
[0038] In the description of the present specification, the description referring to the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.
[0039] The above description is merely preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art, according to the technical solution and the inventive concept of the present application, can make equivalent substitutions or changes within the technical range disclosed by the present application, which should be included in the protection scope of the present application.
Claims
1. A soil retaining and leveling mechanism, characterized in that: The invention comprises a soil retaining scraper plate (1) and an adjustable buffer mechanism (2), wherein the soil retaining scraper plate (1) is provided with a first flip connection portion (11) and a buffer connection portion (12), the adjustable buffer mechanism (2) comprises a telescopic adjustment member (21) and a buffer member (22), the fixed portion of the telescopic adjustment member (21) is provided with a second flip connection portion (23), the telescopic portion of the telescopic adjustment member (21) is provided with an adjustable guide member (24), the adjustable guide member (24) is provided with a main guide channel, and the guiding direction of the main guide channel is parallel to the telescopic direction of the telescopic adjustment member (21). The buffer member (22) passes through the main guide channel and moves relative to the adjustable guide member (24). An upper elastic member (25) and a lower elastic member (26) are respectively provided on the buffer member (22) above and below the adjustable guide member (24), and an upper stop member and a lower stop member are respectively provided above the upper elastic member (25) and below the lower elastic member (26). The bottom end of the buffer member (22) is rotatably connected to the buffer connection portion (12), and the retaining scraper plate (1) rotates relative to the first flip connection portion (11) to drive the buffer member (22) to move along the main guide channel.
2. The soil retaining and leveling mechanism according to claim 1, characterized in that: An upper pin hole is provided on the buffer member (22) above the adjustable guide member (24), an upper stop pin is provided in the upper pin hole, and the upper stop pin is an upper stop member; a lower pin hole is provided on the buffer member (22) below the adjustable guide member (24), a lower stop pin is provided in the lower pin hole, and the lower stop pin is a lower stop member.
3. The soil retaining and leveling mechanism according to claim 2, characterized in that: At least two upper pin holes are provided on the buffer member (22) above the adjustable guide member (24) along the length direction, and the upper stop pin is detachably provided in one of the upper pin holes; at least two lower pin holes are provided on the buffer member (22) below the adjustable guide member (24) along the length direction, and the lower stop pin is detachably provided in one of the lower pin holes.
4. The soil retaining and leveling mechanism according to claim 3, characterized in that: The buffer member (22) is a round rod, and the upper elastic member (25) and the lower elastic member (26) are springs sleeved on the buffer member (22).
5. The soil retaining and leveling mechanism according to claim 4, characterized in that: A retaining ring is provided on the buffer member (22) between the upper elastic member (25) and the upper retaining pin and between the lower elastic member (26) and the lower retaining pin.
6. The soil retaining and leveling mechanism according to claim 4, characterized in that: The fixed portion of the telescopic adjustment member (21) is provided with an auxiliary guide member (27), and the auxiliary guide member (27) is provided with an auxiliary guide channel. The auxiliary guide channel is coaxial with the main guide channel, and the buffer member (22) passes through the auxiliary guide channel. A gap is reserved between the auxiliary guide member (27) and the upper elastic member (25).
7. The soil retaining and leveling mechanism according to claim 6, characterized in that: The adjustable guide member (24) and the auxiliary guide member (27) are guide plates with guide holes formed on the plate surface, and the buffer member (22) passes through the guide holes of each guide plate.
8. The soil retaining and leveling mechanism according to claim 1, characterized in that: A first flip connection portion (11) is provided on the top of the soil retaining scraping plate (1), and a buffer connection portion (12) is provided on the back of the soil retaining scraping plate (1).
9. A land leveling machine, comprising a machine body (3) and a pressing mechanism (4), characterized in that: It also includes a soil retaining and scraping mechanism as described in any one of claims 1 to 7, wherein the first flip connection part (11) is connected to the machine body (3) and the soil retaining and scraping plate (1) is flipped relative to the connection with the machine body (3), and the second flip connection part (23) is connected to the pressing mechanism (4) mounting frame and the telescopic adjustment member (21) rotates relative to the connection with the pressing mechanism (4).
10. The soil preparation machine according to claim 9, characterized in that: A connecting ear is provided on the back of the soil retaining scraper plate (1), a connecting hole is provided on the buffer (22), the connecting ear and the buffer (22) are connected via a connecting pin, and the buffer (22) rotates relative to the connecting ear.