A blackboard lamp with an anti-glare structure

Abstract

The present invention provides a blackboard lamp with an anti-glare structure, which comprises a lamp body, an LED lamp board, and a plurality of lenses. The lamp body includes a housing and end caps provided at both ends of the housing. The housing is provided with a lamp board fixing groove and a receiving cavity extending along the long side direction of the housing. The lamp board fixing groove communicates with the receiving cavity. An opening is provided on one side of the receiving cavity away from the fixing groove. The LED lamp board is arranged in the lamp board fixing groove and is arranged facing the opening; a plurality of lenses are arranged in the receiving cavity, and an anti-glare sheet is arranged between every two adjacent lenses, and the cross-sectional shape of the anti-glare sheet is the same as the cross-sectional shape of the lens. An anti-glare sheet is arranged between adjacent lenses to divide the light beam generated by the LED lamp board, thereby improving the anti-glare ability of the lamp; the anti-glare sheet is clamped between the lenses, and the cross-sectional shapes of the two are the same, so as to hide the anti-glare sheet in the lens, making the lamp thinner and lighter while having an anti-glare effect, which is beneficial to reducing the manufacturing cost of the lamp.

Description

Technical Field

[0001] The present invention relates to the field of lighting, and particularly to a blackboard lamp with an anti-glare structure. Background Art

[0002] At night or in a poor light environment, it is necessary to use blackboard lights to provide lighting so that students can observe the content on the blackboard. In the above usage scenarios, the role of the blackboard light is to illuminate the blackboard, and the students' gazes in the classroom are mainly concentrated on the blackboard. Therefore, the blackboard light should have good anti-glare ability.

[0003] Among them, setting an anti-glare component at the emission end of the light source is a common anti-glare means. However, this external anti-glare component will cause the volume of the lamp to become larger and bloated; on the other hand, fixing the anti-glare component requires increasing the volume of the outer shell, and additional accessories for fixing the anti-glare component need to be made, increasing the manufacturing cost of the lamp. Summary of the Invention

[0004] An object of the present invention is to overcome the deficiencies in the prior art and provide a blackboard lamp with an anti-glare structure.

[0005] The object of the present invention is achieved by the following technical solutions:

[0006] A blackboard lamp with an anti-glare structure, comprising: a lamp body, an LED lamp board, and a plurality of lenses;

[0007] The lamp body includes an outer shell and end caps provided at both ends of the outer shell. The outer shell is provided with a lamp board fixing groove and a receiving cavity extending along the long side direction of the outer shell. The lamp board fixing groove communicates with the receiving cavity. An opening is provided on one side of the receiving cavity away from the fixing groove. The LED lamp board is disposed in the lamp board fixing groove and the LED lamp board faces the opening;

[0008] A plurality of the lenses are disposed in the receiving cavity. An anti-glare sheet is provided between every two adjacent lenses, and the cross-sectional shape of the anti-glare sheet is the same as the cross-sectional shape of the lens.

[0009] In one embodiment, the anti-glare sheet is an aluminum sheet.

[0010] In one embodiment, the lamp body further includes a protective cover. The protective cover is provided with a guard plate and a fixing sleeve. The guard plate is used to close the opening, and the fixing sleeve is connected to the end cap.

[0011] In one embodiment, a limiting portion is provided on the outer wall of the fixing sleeve, and the limiting portion is used to abut against the outer wall of the outer shell.

[0012] In one embodiment, a first limiting strip and a second limiting strip are provided on the outer shell. The first limiting strip and the inner wall of the receiving cavity cooperate to form a first sliding track, and the second limiting strip and the inner wall of the receiving cavity cooperate to form a second sliding track. A first anti-detachment edge and a second anti-detachment edge are provided on the outer wall of the lens. The first anti-detachment edge is located in the first sliding track, and the second anti-detachment edge is located in the second sliding track.

[0013] In one embodiment, the second limiting strip includes a plurality of anti-detachment monomers. The length of the anti-detachment monomer is L1, the length of the lens is L2, and the thickness of the anti-glare sheet is H. L1 = L2 + H. The anti-detachment monomer has a bending portion connected to the outer shell, a contact portion for pressing the second anti-detachment edge, and an elastic bending portion located between the bending portion and the contact portion.

[0014] In one embodiment, a reinforcing rib is provided between the bending portion and the opening.

[0015] In one embodiment, an inclined surface is provided at one end of the lens, and a guiding surface matching the inclined surface is provided on the anti-glare sheet.

[0016] In one embodiment, the lens has a positioning boss located at the edge of the inclined surface, and the positioning boss is inserted into the anti-glare sheet.

[0017] In one embodiment, the lamp body further includes a suspension arm, a special-shaped nut, and a screw. A chute matching the special-shaped nut is provided on the outer shell. A flange is provided on the suspension arm. The screw passes through the flange and is threadedly connected to the special-shaped nut.

[0018] The above-mentioned blackboard lamp with an anti-glare structure has the following advantages:

[0019] 1. An anti-glare sheet is provided between adjacent lenses to divide the light beam generated by the LED lamp board, thereby improving the anti-glare ability of the lamp.

[0020] 2. The anti-glare sheet is clamped between the lenses, and the cross-sectional shapes of the two are the same, so as to hide the anti-glare sheet in the lens. The lamp body does not need to reserve an additional installation position for the anti-glare sheet, making the lamp thinner and lighter while having an anti-glare effect. There is no need to separately set fixing accessories for the anti-glare sheet, which is beneficial to reducing the manufacturing cost of the lamp. Description of the Drawings

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the attached drawings required in the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic structural diagram of a blackboard lamp with an anti-glare structure;

[0023] Figure 2 It is a schematic exploded view of the lamp body;

[0024] Figure 3 It is a schematic cross-sectional view of the housing;

[0025] Figure 4 It is a schematic cross-sectional view of a blackboard lamp with an anti-glare structure;

[0026] Figure 5 It is a diagram (one) of the mating state of the housing and the lens;

[0027] Figure 6 It is a diagram (two) of the mating state of the housing and the lens;

[0028] Figure 7 It is a schematic structural diagram of the lens and the anti-glare sheet;

[0029] Figure 8 It is a schematic mating diagram of the lens and the anti-glare sheet. Detailed implementation manners

[0030] To facilitate the understanding of the present invention, the following will describe the present invention more comprehensively with reference to the relevant attached drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0031] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate 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 intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only embodiments.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0033] Please refer to Figure 1 and Figure 2 , the present invention provides a blackboard lamp 10 with an anti-glare structure, including: a lamp body 100, an LED lamp board 200, and a plurality of lenses 300.

[0034] Please refer to Figure 1 and Figure 3 , the lamp body 100 includes a housing 110 and end caps 120 provided at both ends of the housing 110. The housing 110 is a hollow structure, and the housing 110 is provided with a lamp board fixing groove 111 and a receiving cavity 112 extending along the long side direction of the housing 110 ( Figure 3 the area shown by the dashed line in), the lamp board fixing groove 111 communicates with the receiving cavity 112, and an opening 113 is provided on one side of the receiving cavity 112 away from the fixing groove. The LED lamp board 200 is disposed in the lamp board fixing groove 111, and the LED lamp board 200 is disposed facing the opening 113.

[0035] Please refer to Figure 2 and Figure 3 , a plurality of lenses 300 are disposed in the receiving cavity 112, and an anti-glare sheet 400 is provided between every two adjacent lenses 300. The cross-sectional shape of the anti-glare sheet 400 is the same as the cross-sectional shape of the lens 300 (as Figure 7 shown). That is, the lens 300 and the anti-glare sheet 400 are both located in the receiving cavity 112, and the lens 300 and the anti-glare sheet 400 are alternately arranged. The adjacent lenses 300 are separated by the anti-glare sheet 400. In this way, a grid-shaped anti-glare structure is formed by a plurality of anti-glare sheets 400 in the receiving cavity 112, which can divide the light beam emitted by the LED lamp board 200, effectively block and filter part of the strong light, reduce the reflection and glare effect of the light, and thus enable students to clearly see the information recorded on the blackboard.

[0036] It should be emphasized that the cross-sectional shape of the anti-glare sheet 400 is the same as the cross-sectional shape of the lens 300, and the anti-glare sheet 400 and the lens 300 are substantially alternately stacked in the receiving cavity 112 (as Figure 2As shown in the figure, it is equivalent to integrating the anti-glare structure inside the lens 300, achieving a hidden installation of the anti-glare structure, which can effectively reduce the thickness of the lamp body 100, is beneficial to reducing the volume of the lamp body 100, making the blackboard lamp overall lighter and more beautiful in appearance. On the other hand, the hidden design of the anti-glare sheet 400 makes the anti-glare sheet 400 stacked with the lens 300, without the need to additionally add fixing accessories for the anti-glare sheet 400. At the same time, the anti-glare sheets 400 are not connected to each other, saving materials and reducing the manufacturing cost of the lamp. Among them, the anti-glare sheet 400 is made of common anti-glare materials, such as opaque materials like aluminum sheets, polyester fibers, and black cardboard.

[0037] The assembly method of the blackboard lamp 10 with an anti-glare structure is as follows:

[0038] First, fix one of the end caps 120 to the end of the housing 110;

[0039] On the side where the end cap 120 is not installed, assemble the LED lamp board 200, the lens 300, and the anti-glare sheet. Specifically, first insert the LED lamp board 200 into the lamp board fixing groove 111 so that the lamp beads on the LED lamp board 200 face the opening 113;

[0040] Then, place the lens 300 into the receiving cavity 112, slide it along the receiving cavity 112 until it abuts against the end cap 120, place the anti-glare sheet 400, slide it along the receiving cavity 112 until it fits with the lens 300, and then place the lens 300 into the receiving cavity 112. And so on, alternately place the lens 300 and the anti-glare sheet 400 until the receiving cavity 112 is filled with the anti-glare sheet 400 and the lens 300. Install other accessories inside the lamp (such as a power distributor, a circuit board, etc.) into the housing 110. Finally, install the other end cap 120 to complete the assembly.

[0041] The above-mentioned blackboard lamp 10 with an anti-glare structure has the following advantages:

[0042] 1. An anti-glare sheet 400 is provided between adjacent lenses 300 to divide the light beam generated by the LED lamp board 200, thereby improving the anti-glare ability of the lamp;

[0043] 2. The anti-glare sheet 400 is sandwiched between adjacent lenses 300, and their cross-sectional shapes are the same. In this way, the anti-glare sheet 400 is hidden in the lens 300, and the lamp body 100 does not need to additionally reserve an installation position for the anti-glare sheet 400, making the lamp thinner and lighter while having an anti-glare effect, and not requiring a separate fixing accessory for the anti-glare sheet 400, which is beneficial to reducing the manufacturing cost of the lamp.

[0044] In one embodiment, please refer to Figure 5 and Figure 6, the lamp body 100 further includes a protective cover 130. The protective cover 130 is provided with a guard plate 131 and a fixing sleeve 132. The guard plate 131 covers the opening 113 for closing the opening 113. The fixing sleeve 132 is connected to the end cap 120, and the end cap 120 and the fixing sleeve 132 are locked by screws. After loosening the screws, the guard plate 131 can be toggled to rotate the guard plate 131 around the connection position between the end cap 120 and the fixing sleeve 132, thereby adjusting the angle of the guard plate 131. Wherein, a limiting portion 133 is provided on the outer wall of the fixing sleeve 132 to limit the rotation angle of the guard plate 131 by using the limiting portion 133. When the limiting portion 133 abuts against the outer wall of the housing 110 (such as Figure 5 shown), the guard plate 131 cannot rotate further, avoiding misoperation during the assembly of the lamp to dial the guard plate 131 into the receiving cavity 112, resulting in the inability to normally install the lens 300 and the anti-glare sheet 400.

[0045] Please refer to Figure 3 and Figure 4 , in order to make the assembly process of the lens 300 and the anti-glare sheet 400 simpler, a first limiting strip 114 and a second limiting strip 115 are provided on the housing 110. The first limiting strip 114 and the inner wall of the receiving cavity 112 cooperate to form a first sliding track 11, and the second limiting strip 115 and the inner wall of the receiving cavity 112 cooperate to form a second sliding track 12. A first anti-disengagement edge 310 and a second anti-disengagement edge 320 are provided on the outer wall of the lens 300. During assembly, the first anti-disengagement edge 310 on the lens 300 is aligned with the first sliding track 11, and the second anti-disengagement edge 320 is aligned with the second sliding track 12. After the lens 300 is placed into the receiving cavity 112, the lens 300 can slide along the extending direction of the receiving cavity 112, and the first anti-disengagement edge 310 is located in the first sliding track 11, and the second anti-disengagement edge 320 is located in the second sliding track 12. While providing guidance for the sliding of the lens 300, it can limit the lens 300 to prevent jamming during the sliding process and avoid the deviation of the fixing angle of the lens 300.

[0046] It should be emphasized again that the cross-sectional shape of the anti-glare sheet 400 is the same as the cross-sectional shape of the lens 300, that is, the anti-glare sheet 400 is also provided with structures having the same shape as the first anti-disengagement edge 310 and the second anti-disengagement edge 320. As Figure 7 shown, a third anti-disengagement edge 420 and a fourth anti-disengagement edge 430 are provided on the outer wall of the anti-glare sheet 400 (as Figure 7 shown). After the anti-glare sheet 400 is assembled into the receiving cavity 112, the third anti-disengagement edge 420 is located in the first sliding track 11, and the fourth anti-disengagement edge 430 is located in the second sliding track 12. And the functions of the third anti-disengagement edge 420 and the fourth anti-disengagement edge 430 are the same as those of the first anti-disengagement edge 310 and the second anti-disengagement edge 320, which are used to guide the sliding of the anti-glare sheet 400 and prevent it from deviating.

[0047] It should be noted that in the blackboard lamp disclosed in the present invention, both the lens 300 and the anti-glare sheet 400 are multiple non-connected monomers, which are alternately stacked in the receiving cavity 112. After the lamp is assembled, it is necessary to conduct a power-on test to determine whether the LED lamp board 200 is normally lit and whether the lighting effect is qualified. Among them, since the process of installing the lens 300 into the receiving cavity 112 involves sliding, there is a probability of scratching the outer shell 110 during the assembly process. Therefore, the lens 300 may be scratched during the assembly process or have other defects that cannot be directly observed visually, resulting in a decrease in the light transmission performance at the defective position or obvious shadows when projected onto the blackboard. Therefore, it is necessary to remove the defective lens 300. When the defective lens 300 is located at the end of the outer shell 110, it can be quickly removed by simply disassembling the end cover 120. However, if the defective lens 300 is located in the center of the outer shell 110, after disassembling the end cover 120, it is necessary to first remove the other lenses 300 and anti-glare sheets 400 pressing on this lens 300 before the target lens 300 can be disassembled. The rework process requires removing the non-defective other lenses 300, which affects the rework efficiency. On the other hand, it is necessary to reinstall the removed lens 300 back to its original position, and both the removal and reinstallation processes will increase the risk of scratching the lens 300.

[0048] To solve the above problems, please refer to Figure 2 and Figure 5 , the second limiting strip 115 includes a plurality of anti-detachment monomers 20. The length of the anti-detachment monomer 20 is L1, the length of the lens 300 is L2, and the thickness of the anti-glare sheet 400 is H. L1 = L2 + H. The anti-detachment monomer 20 has a bending portion 21 connected to the outer shell 110, a contact portion 22 for pressing the second anti-detachment edge 320, and an elastic bending portion 23 located between the bending portion 21 and the contact portion 22.

[0049] Preferably, a reinforcing rib 116 is provided between the bending portion 21 and the opening 113.

[0050] Furthermore, please refer to Figure 8 , one end of the lens 300 is provided with an inclined surface 330, and the anti-glare sheet 400 is provided with a guiding surface 410 matching the inclined surface 330. The lens 300 has a positioning boss 340, and the positioning boss 340 is located on the edge of the inclined surface 330. The positioning boss 340 is inserted into the anti-glare sheet 400.

[0051] Among them, the second limit strip 115 and the housing 110 are an integrally formed structure, a gap is provided between adjacent anti-slipping monomers 20, and each anti-slipping monomer 20 is integrally formed with the housing 110, the portion where the anti-slipping monomer 20 is connected to the housing 110 is a curved portion 21, and when no external force is applied, the contact portion 22 and the inner wall of the receiving cavity 112 together form a second slideway 12. After the lens 300 is loaded into the receiving cavity 112, the second anti-slipping edge 320 abuts against the contact portion 22 under the action of gravity.

[0052] After the position of the defective lens 300 is confirmed by inspection, it is only necessary to loosen the screws connected to the protective cover 130, and move the protective plate 131 to flip the protective plate 131 to the side away from the opening 113, so that the lens 300 is exposed (such as Figure 6 shown).

[0053] Next, confirm the anti-detachment monomer 20 that the target lens 300 contacts, apply force to press the contact portion 22 on the anti-detachment monomer 20, bend the elastic bending portion 23, push the contact portion 22 toward the bending portion 21, and thus make the contact portion 22 staggered with the second anti-detachment edge 320 (such as Figure 6 shown).

[0054] The second anti-slip edge 320 on the target lens 300 loses its limit, and the lens 300 tilts toward the side where the second anti-slip edge 320 is located under the action of its own gravity. At this time, the lens 300 can be flipped by simply moving the second anti-slip edge 320 in a direction away from the opening 113, allowing the first anti-slip edge 310 to disengage from the first slide 11, and then the target lens 300 can be taken out.

[0055] When the target lens 300 is removed, an anti-glare sheet 400 affixed to the upper inclined surface 330 thereof will also be taken out, ensuring that there is only one anti-glare sheet 400 between two adjacent lenses 300. Finally, the end cap 120 is opened, and a new lens 300 and anti-glare sheet 400 are loaded on the side where the end cap 120 is located.

[0056] It should be emphasized that there is a gap between adjacent anti-slipping monomers 20, and each anti-slipping monomer 20 contacts and supports the second anti-slipping edge 320 on a lens 300. After confirming the position of the defective lens 300, the anti-slipping monomer 20 in contact with the lens 300 can be directly pressed to make the upper contact portion 22 of the lens 300 staggered with the second anti-slipping edge 320, thereby releasing the lock on the second anti-slipping edge 320. Among them, the present invention is to lock the lens 300 in the receiving cavity 112 by limiting the first anti-slipping edge 310 and the second anti-slipping edge 320 at the same time. When the second anti-slipping edge 320 is staggered with the contact portion 22, there is no other component on the side of the second anti-slipping edge 320 to limit the movement of the lens 300, so the lock on the lens 300 is also released, thereby achieving the purpose of quickly removing the defective lens 300.

[0057] The structural improvement of the second anti-slip edge 320 has the following advantages:

[0058] 1. The defective lens 300 can be quickly taken out from the receiving chamber 112 alone without disassembling other components. The process of taking out the defective lens 300 only requires pressing the anti-detachment monomer 20 and moving the lens 300. The operation is simple and convenient, which reduces the parts that need to be disassembled and assembled during the rework process and greatly improves the rework efficiency of the blackboard lamp.

[0059] 2. The process of picking out defective lenses 300 does not require disassembling other lenses 300 around them, which improves the efficiency of disassembling defective lenses 300 on the one hand, and avoids the wear of other lenses 300 during the disassembly and assembly process on the other hand.

[0060] 3. An inclined structure (inclined surface 330 and guide surface 410) is provided at the contact portion between the lens 300 and the adjacent anti-glare sheet 400, thereby increasing the contact area and increasing the friction between the lens 300 and the anti-glare sheet 400, making it less likely to be misaligned. Furthermore, when the lens 300 contacts the anti-glare sheet 400, the positioning boss 340 is embedded in the anti-glare sheet 400, so that the lens 300 and the anti-glare sheet 400 remain flush. On the other hand, due to the presence of the inclined structure and the positioning boss 340, an anti-glare sheet 400 adjacent to the defective lens 300 (on the side where the inclined surface 330 is located) can be removed at the same time, without the need for additional operations to remove the anti-glare sheet 400, thereby ensuring that only a single anti-glare sheet 400 is present between adjacent lenses 300.

[0061] See also Figure 4 In one embodiment, the lamp body 100 further includes a suspension arm 140, a special-shaped nut 150 and a screw 160. The housing 110 is provided with a slide groove 117 matching the special-shaped nut 150. The suspension arm 140 is provided with a flange 141. The screw 160 passes through the flange 141, and the screw 160 is threadedly connected with the special-shaped nut 150. The suspension arm 140 is fixed on the ceiling, and is connected to the housing 110 through the flange 141, the screw 160 and the special-shaped nut 150, so as to suspend the blackboard lamp above the blackboard, and the special-shaped nut 150 can slide in the slide groove 117, and the position of the suspension arm 140 can be flexibly adjusted according to actual conditions to meet the installation requirements of different environments.

[0062] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A blackboard lamp with an anti-glare structure, characterized in that: include: Lamp body, LED light board, multiple lenses; The lamp body comprises a shell and end covers arranged at both ends of the shell, the shell is provided with a lamp board fixing groove and a receiving cavity extending along the long side direction of the shell, the lamp board fixing groove is communicated with the receiving cavity, an opening is arranged on a side of the receiving cavity away from the fixing groove, the LED lamp board is arranged in the lamp board fixing groove, and the LED lamp board is arranged toward the opening; A plurality of the lenses are arranged in the receiving cavity, an anti-glare sheet is arranged between each two adjacent lenses, and the cross-sectional shape of the anti-glare sheet is consistent with the cross-sectional shape of the lens; The shell is provided with a first limit strip and a second limit strip, the first limit strip cooperates with the inner wall of the accommodating cavity to form a first slide, and the second limit strip cooperates with the inner wall of the accommodating cavity to form a second slide, the outer wall of the lens is provided with a first anti-slip edge and a second anti-slip edge, the first anti-slip edge is located in the first slide, and the second anti-slip edge is located in the second slide; the second limit strip includes a plurality of anti-slip monomers, the length of the anti-slip monomer is L1, the length of the lens is L2, the thickness of the anti-glare sheet is H, L1=L2+H; the anti-slip monomer has a curved portion connected to the shell, a contact portion for pressing the second anti-slip edge and an elastic bending portion located between the curved portion and the contact portion; an inclined surface is provided on one end of the lens, and a guiding surface matching the inclined surface is provided on the anti-glare sheet; the lens has a positioning boss, the positioning boss is located on the edge of the inclined surface, and the positioning boss is inserted into the anti-glare sheet.

2. The blackboard lamp with an anti-glare structure according to claim 1, characterized in that: The anti-glare sheet is an aluminum sheet.

3. The blackboard lamp with an anti-glare structure according to claim 1, characterized in that: The lamp body also includes a protective cover, which is provided with a protective plate and a fixing sleeve, wherein the protective plate is used to close the opening, and the fixing sleeve is connected to the end cover.

4. The blackboard lamp with an anti-glare structure according to claim 3, characterized in that: A limiting portion is provided on the outer wall of the fixing sleeve, and the limiting portion is used to abut against the outer wall of the shell.

5. The blackboard lamp with an anti-glare structure according to claim 1, characterized in that: A reinforcing rib is provided between the bent portion and the opening.

6. The blackboard lamp with an anti-glare structure according to claim 1, characterized in that: The lamp body also includes a hanging arm, a special-shaped nut and a screw. The shell is provided with a slide groove matching the special-shaped nut. The hanging arm is provided with a flange. The screw passes through the flange and is threadedly connected to the special-shaped nut.

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