Quick-release toilet lid capable of being detached only by working personnel and detaching method of quick-release toilet lid

Abstract

The invention discloses a closestool technology, and aims to provide a quick-release closestool cover which can only be detached by a worker and a detaching method of the quick-release closestool cover. According to the technical scheme, the quick-release closestool cover comprises a closestool cover body connected with a closestool through a hinge, and the hinge comprises at least one locking mechanism; the locking mechanism comprises a hinge piece, a steel column, a steel ball and a magnet capable of activating the mechanism; the hinge piece is installed on the toilet lid, the whole hinge piece is square, a cavity for containing the steel ball is formed in the hinge piece, and a channel communicated with the cavity and allowing the steel column to be inserted therein is further formed in the hinge piece; the whole steel column is T-shaped and comprises an insertion part and a limiting part, the insertion part is cylindrical, annular grooves are symmetrically formed in the insertion part, the insertion part can be inserted into the hinge piece along the channel of the hinge piece and makes contact with the steel balls in the cavity in the insertion process, and the steel balls are pushed away to allow the steel column to enter the cavity; the invention is applicable to the technical field of closestools.

Description

Technical Field

[0001] The present invention relates to a toilet technology, and more particularly to a quick-detachable toilet cover which can only be detached by staff and a detaching method thereof. Background Art

[0002] In public places such as public toilets, trains, and airplanes, the toilet seat is an important sanitary facility. Due to the frequent use of toilet seats, they are prone to damage, dirt accumulation, and the need for cleaning and maintenance. Usually, staff need to regularly inspect and clean these facilities. However, many current toilet seat designs allow users to easily disassemble them, resulting in improper use and difficulties in cleaning and maintenance.

[0003] In the prior art, in order to prevent users from disassembling toilet covers at will, many designs make toilet covers inconvenient to disassemble, which makes it very troublesome for workers to repair or clean the toilet covers. Therefore, it is particularly important to be able to realize a convenient and quick-disassembly toilet cover that can be disassembled by only workers. Summary of the invention

[0004] In view of the deficiencies in the prior art, the object of the present invention is to provide a quick-release toilet cover that can only be disassembled by staff and a disassembly method thereof.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solutions: a quick-detachable toilet cover that can only be disassembled by a staff member, comprising a toilet cover connected to the toilet via a hinge, the hinge comprising at least one locking mechanism, the locking mechanism comprising a hinge member, a steel column, a steel ball, and a magnet that can activate the mechanism;

[0006] The hinge is installed on the toilet cover, and the hinge is square in shape as a whole. A cavity for accommodating a steel ball is provided inside the hinge, and a channel communicating with the cavity and for inserting a steel column is also provided on the hinge.

[0007] The steel column is T-shaped as a whole, including an insertion part and a limiting part. The insertion part is cylindrical, and an annular groove is symmetrically provided on the insertion part. The insertion part can be inserted into the hinge part along the channel of the hinge part, and contacts with the steel ball in the cavity during the insertion process. The steel ball is pushed away to allow the steel column to enter the cavity, and when the steel column is fully inserted, the steel ball is stuck in the annular groove of the steel column to prevent the steel column from being pulled out;

[0008] The magnet can act on the steel ball. When the magnet is close to the top of the hinge, the steel ball is attracted by the magnetic force and moves upward, thereby releasing the lock of the steel ball on the steel column, allowing the steel column to be pulled out, thereby realizing the disassembly of the toilet cover.

[0009] The present invention is further configured as follows: the locking mechanism is arranged at the hinge joint of the toilet cover, and the length of the steel column is adapted to the thickness of the toilet cover to ensure that the steel column is not easy to loosen when it is fully inserted into the locking mechanism; the matching accuracy between the steel ball of the locking mechanism and the annular groove on the steel column is 0.2mm to ensure that no loosening or misoperation occurs during operation.

[0010] The present invention is further configured as follows: the size and magnetic strength of the magnet are designed so that when the staff places the magnet, the steel ball moves upward only under the action of the magnetic force, and the magnetic force of the magnet has nothing to do with the strength of daily use, ensuring that the user cannot disassemble it by ordinary tools or force.

[0011] The present invention is further configured as follows: the locking mechanism also includes a spring assembly, which can automatically press the steel ball back to its original position after the magnet is removed; the ratio of the elastic force of the spring assembly to the friction force between the steel ball and the steel column is 1:1-1:2.5, so as to ensure that the steel ball can quickly return to the locked state after the magnet is removed, while avoiding excessive compression of the spring or falling off of the steel ball during the disassembly process.

[0012] A method for disassembling a quick-release toilet cover that can only be disassembled by staff, characterized in that it comprises the following steps:

[0013] S1. Prepare tools: The staff needs to prepare special magnets, the magnetic strength of which should be strong enough to attract the steel balls in the locking mechanism;

[0014] S2, confirming the status: first confirming the status of the toilet cover installed on the toilet, and checking whether the toilet cover is in a locked state;

[0015] S3. Positioning magnet: Place the magnet above the hinge in the locking mechanism, ensuring that the center of the magnet is aligned with the locking part of the locking mechanism;

[0016] S4, attracting steel balls: The magnetic force of the magnet acts on the steel balls in the locking mechanism, and the steel balls begin to move from the annular groove of the steel column in the locking mechanism, and gradually break away from the clamping position of the steel column;

[0017] S5. Observe the unlocking status: Under the magnetic force of the magnet, the steel column begins to unlock. The staff needs to observe whether the steel ball is completely detached and ensure that the position of the magnet does not shift;

[0018] S6. Pull out the steel column: When the steel ball is completely detached, the staff should gently pull out the steel column to ensure that excessive force is not used to damage the locking mechanism components;

[0019] S7. Disassembling the toilet seat: After pulling out the steel column, the toilet seat can be completely disassembled from the hinge joint. The staff should carefully place the disassembled toilet seat;

[0020] S8. Check the installation status: After disassembly, the staff should check the locking mechanism to ensure that the disassembly operation does not cause damage to other components and that they can be successfully installed back to their original position.

[0021] The present invention is further configured as follows: in S3, the staff can use a special positioning device to ensure that the magnet is aligned with the center of the locking mechanism, and the accuracy of the positioning device should reach ±0.5mm; the matching ratio of the accuracy of the positioning device and the magnetic strength of the magnet is 1:10-1:20, so as to ensure the accuracy of the operation during the unlocking process and avoid operation failure due to uneven magnetic force or positioning error.

[0022] The beneficial effects of the present invention are:

[0023] 1. Compared with the prior art, the quick-release toilet cover of the present invention, which can only be disassembled by staff, adopts an innovative locking mechanism, which combines the design of hinges, steel columns, steel balls and magnets, significantly improving the safety and disassembly difficulty of the toilet cover; by using magnets to release the lock of the steel column by the steel ball, it is ensured that only staff with special tools can disassemble it, and ordinary users cannot disassemble it at will; the locking mechanism is exquisitely designed, and the steel column and the steel ball have high matching precision, which can effectively prevent the toilet cover from loosening or misoperation in daily use; in addition, the design improves the durability and stability of the toilet cover, and avoids the problem of loosening or disassembly caused by improper operation or external force; in general, this quick-release toilet cover not only enhances the safety of use, but also improves the efficiency and simplicity of the disassembly process, and reduces the risk of misoperation by non-professionals, which can effectively improve the user experience and service life.

[0024] 2. The quick-release toilet cover of the present invention, which can be removed only by the staff, can ensure that the steel column has good stability and locking effect when it is fully inserted into the locking mechanism by accurately matching the length of the steel column with the thickness of the toilet cover; this design can prevent the steel column from loosening or falling off during use, thereby further enhancing the safety and firmness of the toilet cover; combined with the precise locking mechanism and the matching accuracy requirements between the steel ball and the annular groove of the steel column, it ensures that the friction force and locking effect between the steel column and the steel ball are in the best state, and it is not easy to loosen due to external vibration or friction; in addition, this precise matching also effectively reduces the possibility of misoperation, ensuring that the user will not easily remove the toilet cover even when performing maintenance and cleaning, avoiding safety hazards caused by unauthorized operation.

[0025] 3. In the present invention, the size and magnetic strength of the magnet are designed so that when the staff places the magnet, the steel ball moves upward only under the action of the magnetic force, and the magnetic force of the magnet has nothing to do with the strength of daily use, ensuring that the user cannot disassemble it with ordinary tools or force; this design ensures the exclusivity and safety of the toilet cover disassembly process, and avoids ordinary users or non-professionals from disassembling or misoperating the toilet cover without professional tools. Since the magnetic force of the magnet only acts on the steel ball in the locking mechanism and will not be disturbed by common forces in daily use, the user will not feel any inconvenience or unsafe situation during daily use. This not only improves the safety of disassembly, but also avoids the problem of affecting the disassembly effect due to excessive or weak magnetic force. In general, this design not only protects the safety of users, but also effectively avoids equipment damage or improper use due to non-professional operation.

[0026] 4. The present invention has a reasonable structure, a manufacturing method, and is easy to operate, avoiding the defects of the prior art and is suitable for popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a structural diagram of a toilet.

[0028] Figure 2 This is a cross-sectional structural diagram of a toilet.

[0029] Figure 3 The figure shows the disassembly process of the locking mechanism.

[0030] Figure 1-3 Figure numerals: 1. toilet; 2. toilet lid; 3. locking mechanism; 4. hinge; 5. steel column; 6. steel ball; 7. magnet. DETAILED DESCRIPTION

[0031] Reference Figure 1-3 The quick-detachable toilet seat cover that can only be detached by staff and the embodiment of the detachable method thereof of the present invention are further described.

[0032] For ease of explanation, spatial relative terms such as "upper", "lower", "left", "right" and the like are used in the embodiments to illustrate the relationship of one element or feature shown in the figure relative to another element or feature. It should be understood that, in addition to the orientation shown in the figure, the spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is inverted, the element described as being "under" other elements or features will be positioned "on" other elements or features. Therefore, the exemplary term "under" can include both upper and lower orientations. The device can be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here can be interpreted accordingly.

[0033] Furthermore, relational terms such as “first” and “second” and the like are merely used to distinguish one component from another having the same name, but do not necessarily require or imply any such actual relationship or order between these components.

[0034] Figures 1 to 3 A quick-release toilet cover that can only be removed by staff is shown, comprising a toilet cover 2 connected to a toilet 1 via a hinge, wherein the hinge comprises at least one locking mechanism 3, wherein the locking mechanism 3 comprises a hinge member 4, a steel column 5, a steel ball 6, and a magnet 7 that can activate the mechanism;

[0035] The hinge 4 is mounted on the toilet cover 2, and the hinge 4 is square in shape as a whole. A cavity for accommodating the steel ball 6 is provided in the hinge 4, and a channel communicating with the cavity and for inserting the steel column 5 is also provided on the hinge 4.

[0036] The steel column 5 is T-shaped as a whole, including an insertion portion and a limiting portion. The insertion portion is cylindrical, and an annular groove is symmetrically provided on the insertion portion. The insertion portion can be inserted into the hinge member 4 along the channel of the hinge member 4, and contacts with the steel ball 6 in the cavity during the insertion process. The steel ball 6 is pushed away to allow the steel column 5 to enter the cavity, and when the steel column 5 is fully inserted, the steel ball 6 is stuck in the annular groove of the steel column 5 to prevent the steel column 5 from being pulled out;

[0037] The magnet 7 can act on the steel ball 6. When the magnet 7 is close to the top of the hinge, the steel ball 6 is attracted by the magnetic force and moves upward, thereby releasing the lock of the steel ball 6 on the steel column 5, allowing the steel column 5 to be pulled out, thereby realizing the disassembly of the toilet cover 2;

[0038] Compared with the prior art, the quick-release toilet cover of the present invention, which can only be disassembled by staff, adopts an innovative locking mechanism, which combines the design of hinge 4, steel column 5, steel ball 6 and magnet 7, significantly improving the safety and disassembly difficulty of the toilet cover 2; by using magnet 7 to release the lock of steel ball 6 on steel column 5, it is ensured that only staff with special tools can disassemble it, and ordinary users cannot disassemble it at will; the locking mechanism is exquisitely designed, and the steel column 5 and steel ball 6 have high matching accuracy, which can effectively prevent the toilet cover 2 from loosening or misoperation during daily use; in addition, the design improves the durability and stability of the toilet cover 2, and avoids loosening or disassembly problems caused by improper operation or external force; in general, this quick-release toilet cover 2 not only enhances the safety of use, but also improves the efficiency and simplicity of the disassembly process, and reduces the risk of misoperation by non-professionals, which can effectively improve the user experience and service life.

[0039] The locking mechanism 3 is arranged at the hinge joint of the toilet cover 2, and the length of the steel column 5 is adapted to the thickness of the toilet cover 2, so as to ensure that the steel column 5 is not easy to loosen when fully inserted into the locking mechanism 3; the matching accuracy between the steel ball 6 of the locking mechanism 3 and the annular groove on the steel column 5 is 0.2mm, so as to ensure that there is no loosening or misoperation during the working process;

[0040] By precisely matching the length of the steel column 5 with the thickness of the toilet cover 2, it can be ensured that the steel column 5 has good stability and locking effect when it is fully inserted into the locking mechanism 3; this design can prevent the steel column 5 from loosening or falling off during use, thereby further enhancing the safety and firmness of the toilet cover 2; combined with the precise locking mechanism 3 and the matching accuracy requirements between the steel ball 6 and the annular groove of the steel column 5, it is ensured that the friction force and locking effect between the steel column 5 and the steel ball 6 are in the best state, and are not easily loosened due to external vibration or friction; in addition, this precise matching also effectively reduces the possibility of misoperation, ensuring that the user will not easily remove the toilet cover 2 even during maintenance and cleaning, avoiding safety hazards caused by unauthorized operation.

[0041] The size and magnetic strength of the magnet 7 are designed so that when the staff places the magnet 7, the steel ball 6 moves upward only under the action of the magnetic force, and the magnetic force of the magnet 7 has nothing to do with the strength of daily use, ensuring that the user cannot disassemble it by ordinary tools or force;

[0042] This design ensures the exclusivity and safety of the disassembly process of the toilet cover 2, and prevents ordinary users or non-professionals from disassembling or misoperating the toilet cover 2 without professional tools. Since the magnetic force of the magnet 7 only acts on the steel ball 6 in the locking mechanism 3 and will not be disturbed by common forces in daily use, the user will not feel any inconvenience or unsafe situation during daily use. This not only improves the safety of disassembly, but also avoids the problem of affecting the disassembly effect due to excessive or weak magnetic force. In general, this design not only protects the safety of users, but also effectively avoids equipment damage or improper use due to non-professional operation.

[0043] The locking mechanism 3 also includes a spring assembly, which can automatically press the steel ball 6 back to its original position after the magnet 7 is removed; the ratio of the elastic force of the spring assembly to the friction force between the steel ball 6 and the steel column 5 is 1:1-1:2.5, so as to ensure that the steel ball 6 can quickly return to the locked state after the magnet 7 is removed, and avoid excessive compression of the spring or falling off of the steel ball 6 during the disassembly process;

[0044] The design of the spring assembly not only ensures that the steel ball 6 can quickly return to the locked state after the magnet 7 is removed, preventing the toilet cover 2 from loosening or falling due to improper operation during the disassembly process, but also avoids problems such as excessive compression of the spring or falling of the steel ball 6, ensuring the stability of the locking mechanism 3 and the reliability of long-term use. In addition, this design can effectively reduce the damage to the locking mechanism 3 caused by improper disassembly and extend the service life of the toilet cover 2. By reasonably designing the ratio of the elastic force of the spring assembly to the friction force between the steel ball 6 and the steel column 5, it is ensured that the locking mechanism can maintain the best working state in daily use, and it is not easy to cause the problem of locking failure due to spring failure, thereby improving the safety and reliability of the overall structure.

[0045] A method for disassembling a quick-release toilet cover that can only be disassembled by staff, characterized in that it comprises the following steps:

[0046] S1. Prepare tools: The staff needs to prepare a special magnet 7, the magnetic strength of which should be sufficient to attract the steel ball 6 in the locking mechanism 3;

[0047] S2, confirming the status: first confirming the status of the toilet cover 2 installed on the toilet 1, and checking whether the toilet cover 2 is in a locked state;

[0048] S3, positioning magnet 7: placing magnet 7 above hinge 4 in locking mechanism 3, ensuring that the center of magnet 7 is aligned with the locking part of locking mechanism 3;

[0049] S4, attracting the steel ball 6: the magnetic force of the magnet 7 acts on the steel ball 6 in the locking mechanism 3, and the steel ball 6 begins to move from the annular groove of the steel column 5 in the locking mechanism 3, and gradually leaves the position of the steel column 5;

[0050] S5. Observe the unlocking status: Under the magnetic force of the magnet 7, the steel column 5 begins to unlock. The staff needs to observe whether the steel ball 6 is completely detached and ensure that the position of the magnet 7 does not shift;

[0051] S6. Pull out the steel column 5: When the steel ball 6 is completely detached, the staff should gently pull out the steel column 5 to ensure that excessive force is not used to cause damage to the locking mechanism 3 components;

[0052] S7. Disassembling the toilet cover 2: After pulling out the steel column 5, the toilet cover 2 can be completely disassembled from the hinge joint. The staff should carefully place the disassembled toilet cover 2;

[0053] S8. Check the installation status: After the disassembly is completed, the staff should check the locking mechanism 3 to ensure that the disassembly operation does not cause damage to other components and can be successfully installed back to the original position;

[0054] The disassembly method provided by the present invention is detailed and systematic, ensuring that the staff can operate safely and efficiently when disassembling the toilet cover 2. First, the staff needs to confirm the tool and the locking state to ensure that no misoperation occurs before disassembly. By placing the magnet 7 above the hinge 4 and using the magnetic force to release the locking state, the steel column 5 can be pulled out smoothly, avoiding damage to the locking mechanism 3 due to improper operation or excessive force. Each step in the disassembly process is precisely specified, so that the staff can operate in accordance with the specifications to ensure that no unnecessary risks or misoperations occur during the disassembly process. In addition, the systematic design of the disassembly steps improves the accuracy and efficiency of the operation, and reduces the time waste or equipment damage caused by unskilled operation of personnel; on the whole, this disassembly method not only ensures safety, but also improves the simplicity and standardization of operation, and reduces the safety hazards caused by human factors.

[0055] In S3, the staff can use a special positioning device to ensure that the magnet 7 is aligned with the center of the locking mechanism 3. The accuracy of the positioning device should reach ±0.5mm. The matching ratio of the accuracy of the positioning device and the magnetic strength of the magnet 7 is 1:10-1:20, so as to ensure the accuracy of the operation during the unlocking process and avoid operation failure due to uneven magnetic force or positioning error.

[0056] The accuracy and reliability of the disassembly operation are further improved. The accuracy of the positioning device is required to be ±0.5mm, so that the magnet 7 can accurately act on the key position in the locking mechanism 3 when attracting the steel ball 6, avoiding unlocking failure due to uneven magnetic force or positioning error. This high-precision operation can ensure that the disassembly process is not disturbed by the outside world and avoid unnecessary problems caused by position offset of the magnet 7 or uneven magnetic force distribution. The matching ratio of the positioning device and the magnet 7 enables the disassembly operation to be carried out efficiently and accurately, reducing the operating difficulty and risk of the staff and improving the safety of the disassembly process. By ensuring the correct positioning of the magnet 7 and the precise control of the magnetic force, it can effectively avoid equipment damage or failure of the locking mechanism 3 due to disassembly misoperation, further improving the overall operating efficiency and reliability.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A quick-release toilet cover that can only be disassembled by staff, characterized in that: The invention comprises a toilet cover (2) connected to a toilet (1) via a hinge, wherein the hinge comprises at least one locking mechanism (3), wherein the locking mechanism (3) comprises a hinge member (4), a steel column (5), a steel ball (6) and a magnet (7) capable of activating the mechanism; The hinge (4) is mounted on the toilet cover (2), and the hinge (4) is square in shape as a whole. A cavity for accommodating the steel ball (6) is provided in the hinge (4), and a channel communicating with the cavity and for inserting the steel column (5) is also provided on the hinge (4); The steel column (5) is T-shaped as a whole, and includes an insertion portion and a limiting portion. The insertion portion is cylindrical and symmetrically provided with an annular groove. The insertion portion can be inserted into the hinge member (4) along the channel of the hinge member (4), and during the insertion process, it comes into contact with the steel ball (6) in the cavity. The steel ball (6) is pushed away to allow the steel column (5) to enter the cavity. When the steel column (5) is fully inserted, the steel ball (6) is stuck in the annular groove of the steel column (5) to prevent the steel column (5) from being pulled out. The magnet (7) can act on the steel ball (6). When the magnet (7) is close to the top of the hinge, the steel ball (6) is attracted by the magnetic force and moves upward, thereby releasing the lock of the steel ball (6) on the steel column (5), allowing the steel column (5) to be pulled out, thereby realizing the disassembly of the toilet cover (2).

2. The quick-release toilet cover that can only be removed by staff according to claim 1, characterized in that: The locking mechanism (3) is arranged at the hinge joint of the toilet cover (2), and the length of the steel column (5) is adapted to the thickness of the toilet cover (2) to ensure that the steel column (5) is not easily loosened when fully inserted into the locking mechanism (3); the matching accuracy between the steel ball (6) of the locking mechanism (3) and the annular groove on the steel column (5) is 0.2 mm to ensure that no loosening or misoperation occurs during operation.

3. The quick-release toilet cover that can only be removed by staff according to claim 1, characterized in that: The size and magnetic strength of the magnet (7) are designed so that when a worker places the magnet (7), the steel ball (6) moves upward only under the action of the magnetic force, and the magnetic force of the magnet (7) has nothing to do with the strength of daily use, ensuring that the user cannot disassemble it by ordinary tools or force.

4. The quick-release toilet cover that can only be removed by staff according to claim 1, characterized in that: The locking mechanism (3) further comprises a spring assembly capable of automatically pressing the steel ball (6) back to its original position after the magnet (7) is removed; the ratio of the elastic force of the spring assembly to the friction force between the steel ball (6) and the steel column (5) is 1:1-1:2.5, so as to ensure that the steel ball (6) can quickly return to the locked state after the magnet (7) is removed, while preventing the spring from being over-compressed or the steel ball (6) from falling off during the disassembly process.

5. A method for disassembling a quick-release toilet cover that can only be disassembled by staff according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Prepare tools: The staff needs to prepare a special magnet (7) whose magnetic strength should be sufficient to attract the steel ball (6) in the locking mechanism (3); S2, confirming the status: first confirming the status of the toilet cover (2) installed on the toilet (1), and checking whether the toilet cover (2) is in a locked state; S3, positioning the magnet (7): placing the magnet (7) above the hinge (4) in the locking mechanism (3), ensuring that the center of the magnet (7) is aligned with the locking portion of the locking mechanism (3); S4, attracting the steel ball (6): the magnetic force of the magnet (7) acts on the steel ball (6) in the locking mechanism (3), and the steel ball (6) begins to move from the annular groove of the steel column (5) in the locking mechanism (3), and gradually escapes from the position of the steel column (5); S5. Observe the unlocking state: Under the magnetic force of the magnet (7), the steel column (5) begins to unlock, and the staff needs to observe whether the steel ball (6) is completely detached and ensure that the position of the magnet (7) does not shift; S6. Pull out the steel column (5): When the steel ball (6) is completely detached, the staff should gently pull out the steel column (5), ensuring that excessive force is not applied to cause damage to the locking mechanism (3) components; S7. Disassembling the toilet cover (2): After pulling out the steel column (5), the toilet cover (2) can be completely disassembled from the hinge joint. The staff should carefully place the disassembled toilet cover (2); S8. Check the installation status: After the disassembly is completed, the staff should check the locking mechanism (3) to ensure that the disassembly operation has not caused damage to other components and that it can be successfully installed back to the original position.

6. The method for disassembling a quick-release toilet cover that can only be disassembled by staff according to claim 5, characterized in that: In S3, the staff can use a special positioning device to ensure that the magnet (7) is aligned with the center of the locking mechanism (3). The accuracy of the positioning device should reach ±0.5mm; the matching ratio of the accuracy of the positioning device and the magnetic strength of the magnet (7) is 1:10-1:20, so as to ensure the accuracy of the operation during the unlocking process and avoid operation failure due to uneven magnetic force or positioning error.

Images