A contactless vertical lifting electroplating device

Abstract

The present invention discloses a non-contact vertical lifting electroplating device, which includes a fixed platform, support columns and channel steels; it is characterized in that: the fixed platform, support columns and channel steels jointly constitute the main frame structure of the electroplating device; a buckled U-shaped steel is fixedly connected to the middle of the upper surface of the fixed platform; a vertically arranged oil cylinder is fixedly connected to the middle part of the U-shaped steel through a first support plate; a connecting plate is fixedly connected to the output end of the oil cylinder; the circuit board on the hanging tool can be vertically lifted and horizontally transferred in a non-contact manner; since the circuit board on the hanging tool does not contact objects such as rollers and the inner wall of the electroplating tank, there will be no problems such as bump damage and roller marks that affect the subsequent electroplating effect. In addition, due to the compact structure and good electroplating continuity, there is no need to contact other carriers such as transfer racks during the transfer of the circuit board, and there are fewer external interference factors, the electroplating effect is relatively stable, and the rejection rate of product quality is relatively low.

Description

Technical Field

[0001] The present invention belongs to the technical field of electroplating fixtures, and particularly relates to a non-contact vertical lifting electroplating device. Background Art

[0002] PCB, that is, printed circuit board, its electroplating process plays a crucial role in the production of printed circuit boards. By applying an electrolyte containing copper ions in an electroplating bath and using electrolysis, a layer of copper foil is evenly deposited on the surface of the PCB. This process significantly improves the electrical conductivity, corrosion resistance, and welding performance of the circuit board, ensuring the stability and reliability of circuit connections.

[0003] In the current circuit board electroplating process, a roller conveyor system is usually used to send the circuit board to treatment tanks such as electroplating, water washing, and pickling. In this process, the circuit board serves as the cathode, and the electroplating solution serves as the anode. When the circuit board is immersed in the electroplating bath, a layer of copper foil will be deposited on its surface.

[0004] However, during the electroplating transfer process of the circuit board, since it must be in contact with the rollers for transportation, the contact points between the rollers and the circuit board are extremely likely to leave marks during the transfer process and may rub against the wall of the electroplating bath. These damages will directly affect the quality of subsequent electroplating. Summary of the Invention

[0005] The purpose of the present invention is to provide a non-contact vertical lifting electroplating device to solve the technical problem in the prior art that during the transfer process of the circuit board, it comes into contact with the rollers and the wall of the electroplating bath, which easily generates imprints and frictional damages on the surface of the circuit board, resulting in affecting the subsequent electroplating effect.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A contactless vertical lifting electroplating device, comprising a fixed platform, support columns and channel steels; the fixed platform, support columns and channel steels together constitute the main frame structure of the electroplating device; a U-shaped steel is fixedly connected to the middle of the upper surface of the fixed platform in an inverted manner; a vertically arranged oil cylinder is fixedly connected to the middle of the U-shaped steel through a first support plate; the output end of the oil cylinder is fixedly connected with a connecting plate; columns are arranged on both sides between the U-shaped steel and the channel steel; chain conveying mechanisms are arranged at both the upper and lower ends of the columns; a hoisting mechanism is slidably arranged on the columns; evenly distributed second guide wheels are symmetrically arranged up and down inside the formed main frame; an activity frame that can move horizontally is also symmetrically arranged up and down inside the formed main frame; a first joint is connected to the activity frame in a symmetrical manner; a second joint is connected to one end of the activity frame close to the oil cylinder and the four corners of the connecting plate; a rotatable first guide wheel is fixedly arranged at the position of the channel steel corresponding to the column; a supporting steel wire rope is fixedly connected to the first joint; a main steel wire rope is fixedly connected to the second joint; a moving platform is arranged in the middle inside the formed main frame.

[0008] Preferably, the hoisting mechanism includes a boom slidably arranged on the column, and the boom presents an L-shaped structure; a hanger is hung at the outer end of the boom; two first rollers are rotatably connected to the inner end of the boom, and the first rollers are slidably connected to the inner groove of the column to maintain the horizontal arrangement state of the boom; L-shaped steels are fixedly connected to the end faces on both sides of the moving platform; a fixed rod is fixedly connected to the side of the boom close to the L-shaped steel; a second roller is rotatably connected to the fixed rod.

[0009] Preferably, the main steel wire ropes on the same side are a main steel wire rope group, and there are only four main steel wire rope groups, which are respectively located on both sides of the oil cylinder; the supporting steel wire ropes corresponding to each other up and down are a supporting steel wire rope group; the main steel wire rope group on the same side and any other group of supporting steel wire rope groups form a rectangular rope structure with the head and tail connected.

[0010] Preferably, a bearing seat located above the main frame is fixedly connected to the position of the column corresponding to the bottom of the channel steel; a bearing seat located below the main frame is fixedly connected to the upper surface of the fixed platform through a second support plate; a shaft rod is jointly connected between the bearing seats along the width direction of the main frame.

[0011] Preferably, the second guide wheels located above the main frame inside and the second guide wheels located below the main frame inside are respectively fixedly connected to the corresponding shaft rods.

[0012] Preferably, there are two groups of the activity frames, which are respectively located on both sides of the oil cylinder; the first guide wheels are slidably connected to the activity frames.

[0013] Preferably, the branch wire rope and the main wire rope are respectively wound and connected to the corresponding second guide wheels; there are multiple second guide wheels, which are divided into two groups and are respectively located on both sides of the oil cylinder; the connecting plate is in an I-shaped structure, and the second joint is connected to the four corners on both sides of the connecting plate; one end of the main wire rope away from the second joint is connected to the connecting plate; the ends of the upper and lower corresponding branch wire ropes away from the first joint are fixedly connected to the moving platform through a C-shaped plate.

[0014] Preferably, the fixed platform and the channel steel are parallel to each other, and the channel steel is located above the fixed platform; both sides of the fixed platform and the channel steel are connected to each other through support columns.

[0015] Preferably, a plurality of uniformly arranged cross plates are fixedly connected to the movable frame; the first joints are respectively connected to both sides of the movable frame near one end of the U-shaped steel and both ends of the cross plates.

[0016] Preferably, when the moving platform rises, the L-shaped steel can apply an upward force to all the second rollers thereon, so that the boom moves upward on the column. When the moving platform descends, the boom will automatically follow and descend under the action of gravity, and always keep the second rollers in contact with the upper surface of the L-shaped steel.

[0017] Advantages of the present invention:

[0018] Through the cooperation of the main wire rope and the branch wire rope, the present invention can drive the moving platform to move vertically on the column, and through the chain conveying mechanism, the column can move horizontally within the formed main frame. Therefore, the circuit board on the hanger can be lifted vertically and transferred horizontally without contact; since the circuit board on the hanger does not contact objects such as rollers and the wall of the electroplating tank, problems such as bump damage and roller marks that affect the subsequent electroplating effect will not occur. In addition, due to the compact structure and good electroplating continuity, there is no need to contact other carriers such as transfer racks during the transfer of the circuit board, and there are fewer external interference factors, the electroplating effect is relatively stable, and the rejection rate of product quality is relatively low. Description of the drawings

[0019] The present invention will be further described below with reference to the drawings.

[0020] Figure 1 is a side view of the present invention;

[0021] Figure 2 is Figure 1 a partial enlarged view of A in

[0022] Figure 3 is a front view of the present invention;

[0023] Figure 4 is Figure 3 a partial enlarged view of B in

[0024] Figure 5 is Figure 3 a partial enlarged view at position C in

[0025] Figure 6 is Figure 3 a partial enlarged view at position D in

[0026] Figure 7 a schematic diagram of the cooperation between the main wire rope group and the branch wire rope group in the present invention;

[0027] Figure 8 is a top view of the movable frame in the present invention;

[0028] Figure 9 is a front view of the movable frame in the present invention.

[0029] In the figure: 1, fixed platform; 2, U-shaped steel; 3, support feet; 4, first support plate; 5, oil cylinder; 6, connecting plate; 7, column; 8, first roller; 81, fixed rod; 82, second roller; 9, channel steel; 91, support column; 10, L-shaped steel; 11, first guide wheel; 12, second guide wheel; 13, shaft rod; 14, second support plate; 15, movable frame; 16, cross plate; 17, first joint; 18, main wire rope; 19, branch wire rope; 20, second joint; 21, movable platform; 22, C-shaped plate; 23, bearing seat; 24, boom; 25, hanger. Specific embodiments

[0030] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0031] Please refer to Figure 1 , Figure 3 , the figure and the figure shown. A non-contact vertical lifting electroplating device includes a fixed platform 1 supported on the ground by support feet 3, a support column 91, and a channel steel 9; the fixed platform 1 and the channel steel 9 are parallel to each other, and the channel steel 9 is located above the fixed platform 1; both sides of the fixed platform 1 and the channel steel 9 are connected to each other through the support column 91; the fixed platform 1, the support column 91, and the channel steel 9 together form a main frame structure.

[0032] Please refer to again Figure 1As shown, a U-shaped steel 2 is fixedly connected to the middle of the upper surface of the fixed platform 1 in an inverted manner; columns 7 are arranged on both sides between the U-shaped steel 2 and the channel steel 9; chain conveying mechanisms are arranged at both the upper and lower ends of the column 7, and the chain conveying mechanism includes a sprocket, a chain, and a motor (not shown in the figure), and the chain conveying mechanism is used to drive the column 7 to horizontally move inside the main frame.

[0033] Please refer to again Figure 1 and Figure 2 As shown, a hoisting mechanism is slidably arranged on the column 7; the hoisting mechanism includes a boom 24 slidably arranged on the column 7, and the boom 24 presents an L-shaped structure; a hanger 25 for clamping the circuit board is hung at the outer end of the boom 24; two first rollers 8 are rotatably connected to the inner end of the boom 24, and the first rollers 8 are slidably connected to the inner groove of the column 7 and maintain the horizontal arrangement state of the boom 24.

[0034] Please refer to again Figure 3 and Figure 5 As shown, a vertically arranged oil cylinder 5 is fixedly connected to the middle of the U-shaped steel 2 through an I-shaped first support plate 4; a connecting plate 6 is fixedly connected to the output end of the oil cylinder 5, and the connecting plate 6 presents an I-shaped structure, and second joints 20 are connected to the four corners on both sides of the connecting plate 6.

[0035] Please refer to again Figure 1 、 Figure 3 as well as Figure 6 As shown, uniformly distributed second guide wheels 12 are symmetrically arranged up and down inside the main frame formed, and there are two groups of the second guide wheels 12, and they are respectively located on both sides of the oil cylinder 5; a bearing seat 23 located above the main frame is fixedly connected to the position of the column 7 corresponding to the bottom of the channel steel 9; a bearing seat 23 located below the main frame is fixedly connected to the upper surface of the fixed platform 1 through a second support plate 14; a shaft rod 13 is commonly connected between the bearing seats 23 along the width direction of the main frame, and the second guide wheels 12 located above and the second guide wheels 12 located below are respectively fixedly connected to the corresponding shaft rod 13.

[0036] Please refer to again Figure 1 、 Figure 3 、 Figure 6 、 Figure 8 as well as Figure 9 As shown, movable frames 15 that can move horizontally are also symmetrically arranged up and down inside the main frame formed, and there are two groups of the movable frames 15, and they are respectively located on both sides of the oil cylinder 5; a plurality of uniformly arranged cross plates 16 are fixedly connected to the movable frames 15; symmetrically arranged first joints 17 are connected to both sides of one end of the movable frame 15 close to the U-shaped steel 2 and both ends of the cross plates 16; a second joint 20 is also connected to one end of the movable frame 15 close to the oil cylinder 5, and the first joint 17 and the second joint 20 are used to connect the steel wire ropes.

[0037] Please refer to againFigure 1 and Figure 3 As shown in Figure 3 , rotatable first guide wheels 11 are fixedly arranged at positions of the channel steel 9 corresponding to the columns 7. The first guide wheels 11 are slidably connected to the movable frame 15 and are used to reduce the friction force when the movable frame 15 moves.

[0038] Please refer to again Figure 3 and Figure 4 As shown in Figure 4 , a supporting steel wire rope 19 is fixedly connected to the first joint 17. The supporting steel wire rope 19 is wound and connected with the corresponding second guide wheel 12; the end parts of the mutually corresponding upper and lower supporting steel wire ropes 19 far away from the first joint 17 are fixedly connected with a vertically movable moving platform 21 through a C-shaped plate 22.

[0039] Please refer to again Figure 1 and Figure 2 As shown in Figure 2 , L-shaped steels 10 are fixedly connected to the end faces on both sides of the moving platform 21; a fixing rod 81 is fixedly connected to one side of the boom 24 close to the L-shaped steel 10; a second roller 82 is rotatably connected to the fixing rod 81, and the second roller 82 is located above the L-shaped steel 10.

[0040] Please refer to again Figure 3 , Figure 5 and Figure 6 As shown in Figure 6 , a main steel wire rope 18 is fixedly connected to the second joint 20. The main steel wire rope 18 is also wound and connected with the corresponding second guide wheel 12; one end of the main steel wire rope 18 far away from the second joint 20 is connected to the connecting plate 6 and is used to drive the main steel wire rope 18 to move through the cooperation of the oil cylinder 5 and the connecting plate 6.

[0041] It should be noted here that: as Figure 7 shown in Figure 7 , since each main steel wire rope 18 is connected with a movable frame 15, and the main steel wire ropes 18 on the same side (which can be regarded as a group of main steel wire ropes 18, and there are only four such groups of main steel wire ropes 18, which are respectively located on both sides of the oil cylinder 5) are connected to each other through the connecting plate 6, while the mutually corresponding upper and lower supporting steel wire ropes 19 (which can be regarded as a group of supporting steel wire ropes 19, and there are multiple such groups of supporting steel wire ropes 19, which are also located on both sides of the oil cylinder 5) are connected to each other through the C-shaped plate 22. Therefore, a group of main steel wire ropes 18 on the same side and any other group of supporting steel wire ropes 19 can be regarded as forming a rectangular rope structure with end-to-end connection.

[0042] Furthermore, both the main steel wire rope 18 and the supporting steel wire rope 19 can be replaced by chains. Correspondingly, the second guide wheel 12 needs to be replaced by a gear.

[0043] To facilitate the understanding of the above technical solutions of the present invention, the working principle or operation method of the present invention in the actual process will be described in detail below:

[0044] First, clamp and fix the circuit board to be processed on the hanger 25, then hang the hanger 25 on both sides of the moving platform 21 respectively, and then use the oil cylinder 5 to drive the connecting plate 6 to move up and down.

[0045] When the connecting plate 6 moves upward, since the 18 groups of main steel wires ropes on the same side and any other 19 groups of branch steel wire ropes can be regarded as constituting a rectangular rope structure with head and tail connected, one group of main steel wire ropes 18 can cooperate with one group of branch steel wire ropes 19 to drive the movable frame 15 to move. Also, since the other 19 groups of branch steel wire ropes are connected to the movable frame 15, all 19 groups of branch steel wire ropes can move synchronously. At this time, because the branch steel wire ropes 19 are connected to the moving platform 21 through the C-shaped plates 22, under the guiding action of the second guide wheels 12, the moving platform 21 can rise synchronously, so that the hangers 25 carried thereon rise synchronously, and the balance on both sides of the moving platform 21 is better. In addition, since the main steel wire ropes 18 and branch steel wire ropes 19 located in the upper part and the main steel wire ropes 18 and branch steel wire ropes 19 located in the lower part are both connected to the moving platform 21, balance can be achieved during the rising process, maintaining the balance of the moving platform 21 in all directions around and up and down, and ensuring that the moving platform 21 will not tip over.

[0046] Using the same mechanical mechanism, when the connecting plate 6 moves downward, the moving platform 21 can be stably lowered within the formed main frame structure, so as to realize the function of the moving platform 21 carrying the hanger 25 to rise and fall freely.

[0047] During this process:

[0048] Since the oil cylinder 5 cooperates with the main steel wire ropes 18, branch steel wire ropes 19 and the movable frame 15, the moving platform 21 and the hoisting mechanism carried thereon can be stably vertically lifted from one of the electroplating tanks and lifted to a position above the electroplating tank. Then, the motor in the chain conveying mechanism drives the sprocket to rotate, and the sprocket drives the column 7 to move horizontally at the upper and lower ends of the column 7 through the chain respectively, so that the hoisting mechanism can move horizontally smoothly. After that, move it above another electroplating tank, and then the oil cylinder 5 can be used to stably vertically lower the moving platform 21 again, so as to achieve the purpose of immersing the hanger 25 in another electroplating, pickling and water washing tanks.

[0049] Among them, when the moving platform 21 rises, the L-shaped steel 10 can apply an upward force to all the second rollers 82 thereon, so that the boom 24 moves upward on the column 7. When the moving platform 21 descends, the boom 24 will automatically follow and descend under the action of gravity, always keeping the second rollers 82 in contact with the upper surface of the L-shaped steel 10.

[0050] Among them, through the cooperation of the main wire rope 18 and the branch wire rope 19, the moving platform 21 can be driven to move vertically on the column 7, and through the chain conveying mechanism, the column 7 can be moved horizontally within the formed main frame. Therefore, the circuit board on the fixture 25 can be lifted vertically and transferred horizontally without contact. Since the circuit board on the fixture 25 does not contact objects such as rollers and the wall of the electroplating tank, problems such as bump damage and roller marks that affect the subsequent electroplating effect will not occur. In addition, due to the compact structure and good electroplating continuity, there is no need to contact other carriers such as transfer racks during the transfer of the circuit board, and there are fewer external interference factors, the electroplating effect is relatively stable, and the rejection rate of product quality is relatively low.

[0051] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0052] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A contactless vertical lifting electroplating device, comprising a fixed platform (1), a support column (91) and a channel steel (9); characterized in that: The fixed platform (1), the support column (91) and the channel steel (9) together constitute the main frame structure of the electroplating device; a U-shaped steel (2) buckled is fixedly connected to the middle of the upper surface of the fixed platform (1); a vertically arranged oil cylinder (5) is fixedly connected to the middle of the U-shaped steel (2) through a first support plate (4); a connecting plate (6) is fixedly connected to the output end of the oil cylinder (5); Columns (7) are arranged on both sides between the U-shaped steel (2) and the channel steel (9); chain conveying mechanisms are arranged at both the upper and lower ends of the columns (7); a hoisting mechanism is slidably arranged on the columns (7); Evenly distributed second guide wheels (12) are symmetrically arranged up and down inside the main frame formed; an activity frame (15) that can move horizontally is also symmetrically arranged up and down inside the main frame formed; symmetrically arranged first joints (17) are connected to the activity frame (15); second joints (20) are connected to one end of the activity frame (15) close to the oil cylinder (5) and the four corners of the connecting plate (6); rotatable first guide wheels (11) are fixedly arranged at the positions of the channel steel (9) corresponding to the columns (7); a supporting steel wire rope (19) is fixedly connected to the first joint (17); a main steel wire rope (18) is fixedly connected to the second joint (20); a moving platform (21) is arranged in the middle inside the main frame formed; First, clamp and fix the circuit board to be processed on the hanger, then hang the hangers on both sides of the moving platform respectively, and then drive the connecting plate to move up and down by using the oil cylinder; when the connecting plate moves upward, since the main steel wire rope group on the same side and any other group of supporting steel wire rope groups are regarded as forming a rectangular rope structure with end-to-end connection, a main steel wire rope group cooperates with one of the supporting steel wire rope groups to drive the activity frame to move; and because the other supporting steel wire rope groups are connected to the activity frame, all the supporting steel wire rope groups move synchronously; at this time, because the supporting steel wire rope is connected to the moving platform through a U-shaped plate, under the guiding action of the second guide wheel, the moving platform rises synchronously, so that the hangers carried on it rise synchronously, and the balance of both sides of the moving platform is better; in addition, because the main steel wire ropes and supporting steel wire ropes in the upper part and the main steel wire ropes and supporting steel wire ropes in the lower part are all connected to the moving platform, balance is achieved during the rising process, and the balance of the moving platform in all directions around and up and down is maintained, ensuring that the moving platform will not tip over; Using the same mechanical mechanism, when the connecting plate moves downward, the moving platform is stably lowered within the main frame structure formed, so as to realize the function of the moving platform carrying the hanger rising and falling freely.

2. The non-contact vertical lifting electroplating equipment according to claim 1 is characterized in that: The hoisting mechanism includes a boom (24) slidably arranged on the column (7), and the boom (24) presents an L-shaped structure; a hanger (25) is hung at the outer end of the boom (24); two first rollers (8) are rotatably connected to the inner end of the boom (24), and the first rollers (8) are slidably connected to the inner groove of the column (7) and maintain the horizontal arrangement state of the boom (24); L-shaped steel (10) is fixedly connected to the end surfaces on both sides of the mobile platform (21); a fixing rod (81) is fixedly connected to a side of the suspension arm (24) close to the L-shaped steel (10); and a second roller (82) is rotatably connected to the fixing rod (81).

3. The non-contact vertical lifting electroplating equipment according to claim 1 is characterized in that: The main steel wire ropes (18) on the same side form a main steel wire rope (18) group, which has only four main steel wire ropes (18) and are respectively located on both sides of the oil cylinder (5); the upper and lower corresponding branch steel wire ropes (19) form a branch steel wire rope (19) group; The main steel wire rope (18) group and any other group of branch steel wire ropes (19) on the same side form a rectangular rope structure connected end to end.

4. The non-contact vertical lifting electroplating equipment according to claim 1 is characterized in that: The column (7) is fixedly connected to a bearing seat (23) located above the main frame at a position corresponding to the bottom of the channel steel (9); the upper surface of the fixed platform (1) is fixedly connected to a bearing seat (23) located below the main frame via a second support plate (14); and a shaft (13) is commonly connected between the bearing seats (23) along the width direction of the main frame.

5. The non-contact vertical lifting electroplating equipment according to claim 4 is characterized in that: The second guide wheel (12) located at the upper part of the main frame and the second guide wheel (12) located at the lower part of the main frame are respectively fixedly connected to corresponding shaft rods (13).

6. The non-contact vertical lifting electroplating equipment according to claim 1, characterized in that: The movable frames (15) are provided in two groups and are respectively located on both sides of the oil cylinder (5); the first guide wheel (11) is slidably connected to the movable frame (15).

7. The non-contact vertical lifting electroplating equipment according to claim 1, characterized in that: The support steel wire rope (19) and the main steel wire rope (18) are respectively wound and connected to the corresponding second guide wheels (12); a plurality of second guide wheels (12) are provided, and the second guide wheels (12) are divided into two groups, which are respectively located on both sides of the oil cylinder (5); The connecting plate (6) is in an I-shaped structure, and the second joints (20) are connected to the four corners on both sides of the connecting plate (6); one end of the main steel wire rope (18) away from the second joint (20) is connected to the connecting plate (6); The ends of the upper and lower corresponding support wire ropes (19) away from the first joint (17) are fixedly connected to the mobile platform (21) via the shaped plate (22).

8. The non-contact vertical lifting electroplating equipment according to claim 1, characterized in that: The fixed platform (1) and the channel steel (9) are parallel to each other, and the channel steel (9) is located above the fixed platform (1); the fixed platform (1) and the channel steel (9) are connected to each other on both sides via support columns (91).

9. The non-contact vertical lifting electroplating equipment according to claim 1, characterized in that: The movable frame (15) is fixedly connected to a plurality of evenly distributed transverse plates (16); the first joints (17) are respectively connected to two sides of the movable frame (15) close to one end of the U-shaped steel (2) and two ends of the transverse plates (16).

10. The non-contact vertical lifting electroplating equipment according to claim 2, characterized in that: When the mobile platform (21) rises, the L-shaped steel (10) applies an upward force to all the second rollers (82) thereon, thereby causing the boom (24) to move upward on the column (7); when the mobile platform (21) descends, the boom (24) automatically follows the descent under the action of gravity, always keeping the second rollers (82) in contact with the upper surface of the L-shaped steel (10).

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