Welding machine for stainless steel pipeline fitting machining

Abstract

The invention discloses a welding machine for stainless steel pipeline pipe fitting machining, and belongs to the technical field of stainless steel pipeline welding. The welding machine comprises a machine body, a vertical plate is arranged on the upper surface of the machine body, a motor is connected to the surface of the vertical plate through bolts, a mechanical arm is arranged on the upper surface of the machine body, and the machine body completes welding through the mechanical arm; the output end of the motor is fixedly connected with a connecting shaft; a supporting block is arranged on the upper surface of the machine body, and a long pin is rotationally arranged in the supporting block. According to the welding machine for stainless steel pipeline pipe fitting machining, when a pipeline needs to be clamped, the pipeline is placed on a lower clamping plate, then an upper clamping plate is rotated, after an auxiliary plate enters a connecting block, a clamping block enters a clamping groove, at the moment, the pipeline is clamped and fixed through the upper clamping plate and the lower clamping plate, and in the working process, a motor can drive the pipeline to rotate; and meanwhile, the cleaning plate is in a working state, so that the welding slag is not adhered to the machine body, and the cleaning of workers is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of stainless steel pipeline welding, in particular to a welding machine used for processing stainless steel pipeline fittings. Background Art

[0002] Stainless steel pipes have excellent corrosion resistance, strength and hygiene, and are widely used in industries such as industry, food and construction. When stainless steel pipes are processed or used, they need to be welded, so that stainless steel pipes can be produced and used according to actual conditions, which improves the flexibility of stainless steel pipes. In the welding process, a welding machine is needed. When the welding machine is used, the pipe needs to be clamped and fixed quickly to facilitate the stability of welding. If the pipe cannot be clamped and fixed quickly, the welding efficiency will be affected. In order to overcome this defect, prior art 1 (application number 201711160487.X, Chinese patent application application date 2017-11-20) is a natural gas pipeline welding machine. During use, the structure is provided with a pipeline locking structure. The upper and lower clamps only clamp the pipeline without shaking, so that the welding is carried out smoothly, the welding effect is improved, and the pipeline can be used more stably. The service life is increased and the safety hazards in use are reduced. Prior art 2 (Chinese patent application with application number 202320886780.9 and application date 2023-04-19) is an elbow welding machine. During use, when it is necessary to weld the bottom of the pipe connection, the first handle is rotated. When the first handle is rotated, it will drive the first bidirectional screw to rotate, thereby causing the two first clamping plates to move. When the two first clamping plates are released from the fixation of the elbow pipe, the locking handle is pulled to cause the locking plate to disengage from the locking groove under the action of the locking handle. When the locking plate is released from the locking groove, the rotating plate is released from the control of the locking plate, so that the rotating plate can rotate freely in the rotating groove, and then the round pipe is rotated to adjust the unwelded part of the pipe to a suitable position, thereby facilitating the welding worker to operate the welding machine body to weld the pipe. When the round pipe is rotated to a suitable angle, the locking handle is released, and the locking plate will be stuck in the locking groove under the action of the spring, thereby fixing the rotating plate.

[0003] During the operation of the welding machine, a large amount of welding slag is generated. However, the device in the above application does not have a welding slag processing structure, which will cause the welding slag to adhere to the machine body, causing unnecessary trouble for subsequent cleaning by the staff. Summary of the Invention

[0004] The purpose of the present invention is to provide a welding machine for processing stainless steel pipe fittings, so as to solve the problem proposed in the above background technology that there is no welding slag processing structure, which will cause the welding slag to stick to the machine body, causing unnecessary trouble for subsequent cleaning by the staff.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a welding machine for processing stainless steel pipe fittings, comprising a body, the upper surface of the body is provided with a vertical plate, and the surface of the vertical plate is bolted to a motor, and a mechanical arm is provided on the upper surface of the body, the body completes welding through the mechanical arm, and the output end of the motor is fixedly connected to a connecting shaft; a circular plate is provided on the inner side of the vertical plate, and the inner side of the circular plate is fixedly connected to a lower clamping plate, and the lower clamping plate is connected to the upper clamping plate through a locking mechanism; a support block is provided on the upper surface of the body, and a long pin is provided for rotation inside the support block, and a sliding frame is movably provided on the inner side of the support block, and the sliding frame is connected to a cleaning plate through a swinging mechanism; a docking plate is fixedly connected to the upper surface of the body, and an airbag is bonded to the surface of the docking plate; a long plate is provided on the upper surface of the cleaning plate, and a nozzle is fixedly connected to the lower surface of the long plate.

[0006] Preferably, the connecting shaft is fixedly connected to the circular plate, the circular plates are symmetrically distributed on both sides of the body, and a support plate is fixedly connected to the upper surface of the body, and a ball is rotatably provided inside the support plate, and the surface of the ball fits the surface of the circular plate, and one end of the lower splint and one end of the upper splint are connected by a hinge, and the locking mechanism includes a fixed block fixedly connected to the surface of the upper splint, and also includes a connecting block fixedly connected to the surface of the lower splint.

[0007] Preferably, the lower surface of the fixed block is fixedly connected to an auxiliary plate, and a card slot is provided on both the left and right sides of the auxiliary plate. A card block corresponding to the card slot is slidingly provided inside the connecting block, and the outer end of the card block is convex, and the inner surface of the card block is inclined.

[0008] Preferably, a first spring is fixedly connected to the end protrusion of the blocking block, and the other side of the first spring is fixedly connected to the inner wall of the connecting block. A push rod is slidingly provided inside the connecting block, and a second spring is fixedly connected between the lower surface of the push rod and the connecting block.

[0009] Preferably, the connecting shaft is connected to the long pin through a pulley, a slider is fixedly connected to the upper surface of the sliding frame, and tooth blocks are arranged at equal intervals on the inner wall of the sliding frame, a limiting rod is fixedly connected to the inner wall of the support block, and the limiting rod is an inverted "U" shape when viewed from above, and the surface of the limiting rod is sleeved with the slider.

[0010] Preferably, the swing mechanism includes a working gear fixedly connected to the end of the long pin, and the working gear is a non-full gear structure, and the working gear is meshed with the gear block, and the lower surface of the sliding frame is fixedly connected with a lower connecting block.

[0011] Preferably, an inner connecting plate is slidingly provided inside the lower connecting block, and a groove is provided on the upper surface of the inner connecting plate. An auxiliary rod is fixedly connected to the inner wall of the support block, and the auxiliary rod is an inverted "L" structure when viewed from the front.

[0012] Preferably, the end of the auxiliary rod is located inside the groove, and the groove is curved, and the cleaning plate is inserted inside the inner plate.

[0013] Preferably, a delivery pipe is fixedly connected to the surface of the long board, an air inlet pipe is fixedly connected to the left side of the airbag, and an air outlet pipe is fixedly connected to the right side of the airbag, and the air outlet pipe is connected to the delivery pipe through an external hose.

[0014] Preferably, the end of the delivery pipe is located at the lower side of the cleaning plate, and an inclined guide plate is provided on the upper surface of the cleaning plate, and the delivery pipes are distributed at equal intervals on the lower surface of the long plate.

[0015] Compared with the prior art, the present invention has the following beneficial effects: a novel structural design is adopted, and the upper and lower clamping plates are provided to quickly fix the pipe. Then, during welding, the pipe is rotated by a motor according to actual needs. During this process, the cleaning plate is in a reciprocating state, which can maximize the cleaning effect, making it easier for workers to clean the welding slag after welding. In addition, an air bag and a nozzle are provided to cool the welding slag, making it easier to clean the welding slag and improving work efficiency. The specific contents are as follows: (1) The welding machine used for processing stainless steel pipe fittings, when it is necessary to clamp the pipe, the pipe is placed on the lower clamping plate, and then the upper clamping plate is rotated. After the auxiliary plate enters the interior of the connecting block, the clamping block will enter the interior of the clamping groove. At this time, the upper and lower clamping plates clamp and fix the pipe. During the working process, the motor can drive the pipe to rotate, and the cleaning plate is in a working state, which can prevent the welding slag from adhering to the machine body, making it easier for the staff to clean.

[0016] Furthermore, when the upper splint needs to be opened, the card block is pulled to move the end of the card block out of the card slot. At this time, the fixed block and the connecting block are not in a locked state, and then the push rod and the second spring push the upper splint open. The push rod and the second spring play a role in assisting disassembly, thereby improving work efficiency.

[0017] (2) The welding machine used for processing stainless steel pipe fittings, during operation, when the motor drives the circular plate to rotate through the connecting shaft, the connecting shaft drives the long pin to rotate through the pulley. At this time, the sliding frame performs reciprocating linear motion in the horizontal direction, and the sliding frame drives the lower connecting block, the inner connecting plate and the cleaning plate to move synchronously. At this time, the cleaning plate can clean the welding slag very well, so that the welding slag does not stick to the machine body. At the same time, the guide plate on the upper surface of the cleaning plate also plays a role in concentrating the welding slag, which is convenient for collecting the welding slag.

[0018] Furthermore, during the movement of the inner connecting plate and the cleaning plate, the inner connecting plate and the groove are equivalent to the movement of the auxiliary rod. At this time, the auxiliary rod drives the inner connecting plate to move inside the lower connecting block through the groove. At this time, the movement range of the cleaning plate is increased, and the cleaning effect is optimized.

[0019] (3) In the welding machine used for processing stainless steel pipe fittings, during the movement of the lower connecting block, the lower connecting block will intermittently squeeze the air bag on the surface of the docking plate. At this time, the air bag will supply air to the nozzle through the outlet pipe and the delivery pipe, so that the nozzle can cool the welding slag, making it easier for the welding slag to be quickly cleaned. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the connection structure between the body and the lower splint of the present invention; Figure 2 This is a schematic diagram of the connection structure between the lower and upper splints of the present invention; Figure 3 This is a structural diagram of the distribution state of the fixed blocks and the connecting blocks of the present invention; Figure 4 This is a schematic structural diagram of a cross-section state of the connecting block of the present invention; Figure 5 This is a schematic diagram of the connection structure between the connecting block and the push rod of the present invention; Figure 6 This is a schematic diagram of the connection structure between the support block and the long pin of the present invention; Figure 7 This is a schematic diagram of the connection structure between the sliding frame and the slider of the present invention; Figure 8 This is a schematic diagram of the gear block distribution structure of the present invention; Figure 9 This is a schematic diagram of the groove distribution structure of the present invention; Figure 10 This is a schematic diagram of the connection structure between the docking plate and the airbag of the present invention; Figure 11 This is a schematic diagram of the nozzle distribution structure of the present invention.

[0021] In the figure: 1. body; 2. vertical plate; 3. motor; 4. support plate; 5. connecting shaft; 6. circular plate; 7. lower clamping plate; 8. upper clamping plate; 9. long pin; 10. fixing block; 11. connecting block; 12. clamping block; 13. auxiliary plate; 14. clamping groove; 15. first spring; 16. push rod; 17. second spring; 18. support block; 19. limit rod; 20. slider; 21. sliding frame; 22. gear block; 23. working gear; 24. auxiliary rod; 25. lower connecting block; 26. cleaning plate; 27. inner connecting plate; 28. groove; 29. long plate; 30. conveying pipe; 31. nozzle; 32. docking plate; 33. airbag. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] The present invention provides the following technical solution: a welding machine for processing stainless steel pipelines and pipe fittings.

[0024] Embodiment 1: By setting the lower clamping plate 7 and the upper clamping plate 8, the pipe can be clamped and fixed quickly, such as Figure 1-Figure 5 As shown, it includes a body 1, a vertical plate 2 is provided on the upper surface of the body 1, and a motor 3 is bolted to the surface of the vertical plate 2, and a mechanical arm is provided on the upper surface of the body 1, and the body 1 is welded by the mechanical arm, and the output end of the motor 3 is fixedly connected to the connecting shaft 5; a circular plate 6 is provided on the inner side of the vertical plate 2, and a lower clamping plate 7 is fixedly connected to the inner side of the circular plate 6, and the lower clamping plate 7 is connected to the upper clamping plate 8 through a locking mechanism; The connecting shaft 5 is fixedly connected to the circular plate 6, and the circular plates 6 are symmetrically distributed on both sides of the body 1. The upper surface of the body 1 is fixedly connected to the support plate 4, and a ball is provided inside the support plate 4 for rotation. The surface of the ball fits the surface of the circular plate 6. The end of one side of the lower splint 7 and the end of one side of the upper splint 8 are connected by a hinge. The locking mechanism includes a fixed block 10 fixedly connected to the surface of the upper splint 8, and also includes a connecting block 11 fixedly connected to the surface of the lower splint 7.

[0025] An auxiliary plate 13 is fixedly connected to the lower surface of the fixed block 10, and a card slot 14 is provided on the left and right sides of the auxiliary plate 13. A card block 12 corresponding to the card slot 14 is slidingly provided inside the connecting block 11, and the outer end of the card block 12 is convex, and the inner surface of the card block 12 is inclined. The end convex position of the card block 12 is fixedly connected to the first spring 15, and the other side of the first spring 15 is fixedly connected to the inner wall of the connecting block 11. A push rod 16 is slidingly provided inside the connecting block 11, and a second spring 17 is fixedly connected between the lower surface of the push rod 16 and the connecting block 11.

[0026] When it is necessary to fix the pipe to be processed, the pipe is placed in the lower clamping plate 7. At this time, the upper clamping plate 8 is rotated, and the auxiliary plate 13 on the lower surface of the fixed block 10 will enter the interior of the connecting block 11, and the auxiliary plate 13 will push the clamping block 12, so that the clamping block 12 moves in the direction of stretching the first spring 15. When the upper clamping plate 8 is rotated, the clamping block 12 and the clamping slot 14 are in the same horizontal direction, and the clamping block 12 enters the interior of the clamping slot 14 under the action of the first spring 15. At this time, the lower clamping plate 7 and the upper clamping plate 8 are engaged, and the pipe is clamped. After that, the welding is completed by the mechanical arm on the upper surface of the body 1 and the welding head set on the mechanical arm. In this process, the fixed block 10 will push the push rod 16, so that the push rod 16 squeezes the second spring 17.

[0027] During the welding process, when the angle needs to be adjusted, the motor 3 can be started. The motor 3 drives the circular plate 6 to rotate through the connecting shaft 5, and then the pipe rotates, which improves the flexibility of welding. After the welding is completed, when the upper clamping plate 8 needs to be opened, the clamping block 12 is pulled to move the end of the clamping block 12 out of the clamping slot 14. At this time, the push rod 16 pushes the upper clamping plate 8 under the action of the second spring 17, so that the upper clamping plate 8 can be opened more quickly, and the pipe can be taken out more quickly, thereby improving work efficiency.

[0028] Embodiment 2: The difference from embodiment 1 is that the cleaning plate 26 is provided to clean the welding slag so that the welding slag will not adhere to the machine body 1. Figure 6-Figure 9 As shown, a support block 18 is provided on the upper surface of the body 1, and a long pin 9 is rotatably provided inside the support block 18, and a sliding frame 21 is movably provided on the inner side of the support block 18, and the sliding frame 21 is connected to the cleaning plate 26 through a swinging mechanism; the connecting shaft 5 is connected to the long pin 9 through a pulley, and a slider 20 is fixedly connected to the upper surface of the sliding frame 21, and tooth blocks 22 are evenly spaced on the inner wall of the sliding frame 21, and a limiting rod 19 is fixedly connected to the inner wall of the support block 18, and the limiting rod 19 is an inverted "U" shape when viewed from above, and the surface of the limiting rod 19 is sleeved with a slider 20.

[0029] The swing mechanism includes a working gear 23 fixedly connected to the end of the long pin 9, and the working gear 23 is a non-full gear structure, and the working gear 23 is meshed with the gear block 22, and the lower surface of the sliding frame 21 is fixedly connected with a lower connecting block 25.

[0030] An internal connecting plate 27 is slidingly provided inside the lower connecting block 25, and a groove 28 is provided on the upper surface of the internal connecting plate 27. An auxiliary rod 24 is fixedly connected to the inner wall of the support block 18, and the auxiliary rod 24 is an inverted "L" structure when viewed from the front. The end of the auxiliary rod 24 is located inside the groove 28, and the groove 28 is curved. The cleaning plate 26 is inserted inside the internal connecting plate 27.

[0031] When the connecting shaft 5 rotates, the long pin 9 rotates under the action of the pulley. At this time, the long pin 9 drives the working gear 23 to rotate. The working gear 23 is a non-full gear structure, and cooperates with the sliding frame 21 and the tooth block 22 to move the sliding frame 21 (the slider 20 and the limit rod 19 make the sliding frame 21 move only in the horizontal direction). At this time, the sliding frame 21 drives the lower connecting block 25, the internal connecting plate 27 and the cleaning plate 26 to work, and then the cleaning plate 26 can clean the welding slag and prevent the welding slag from sticking. The guide plate on the upper surface of the cleaning plate 26 plays the role of guiding and collecting welding slag. The guide plate is in a moving and shaking state, and no welding slag remains, which facilitates the falling of welding slag.

[0032] When the lower connecting block 25 drives the inner connecting plate 27 and the cleaning plate 26 to move, the inner connecting plate 27 and the groove 28 move relative to the auxiliary rod 24. At this time, the auxiliary rod 24 and the groove 28 cooperate to make the inner connecting plate 27 slide inside the lower connecting block 25. At this time, the inner connecting plate 27 and the cleaning plate 26 move telescopically inside the lower connecting block 25, thereby increasing the moving path of the cleaning plate 26 and optimizing the cleaning effect.

[0033] Embodiment 3: Different from embodiment 2, the air bag 33 and the nozzle 31 are provided to quickly cool down the welding slag. Figure 10-11 As shown, a docking plate 32 is fixedly connected to the upper surface of the body 1, and an airbag 33 is adhered to the surface of the docking plate 32; a long plate 29 is provided on the upper surface of the cleaning plate 26, and a nozzle 31 is fixedly connected to the lower surface of the long plate 29.

[0034] A delivery pipe 30 is fixedly connected to the surface of the long plate 29, an air inlet pipe is fixedly connected to the left side of the airbag 33, and an air outlet pipe is fixedly connected to the right side of the airbag 33, and the air outlet pipe is connected to the delivery pipe 30 through an external hose. The end of the delivery pipe 30 is located on the lower side of the cleaning plate 26, and an inclined guide plate is provided on the upper surface of the cleaning plate 26, and the delivery pipes 30 are evenly spaced on the lower surface of the long plate 29.

[0035] During the movement of the lower connecting block 25, the lower connecting block 25 will intermittently squeeze the airbag 33 on the surface of the docking plate 32. When the airbag 33 is squeezed, the airbag 33 will supply air to the nozzle 31 through the air outlet pipe and the delivery pipe 30, so that the nozzle 31 can cool the welding slag, which is convenient for the welding slag to be quickly cleaned. When the airbag 33 is not squeezed, the airbag 33 takes in air through the air inlet pipe, which is convenient for the next use of the airbag 33. At the same time, the surfaces of the air inlet pipe and the air outlet pipe are both provided with one-way valves, so that the airflow only flows from the airbag 33 to the nozzle 31, ensuring the stability of the airflow operation.

[0036] The above is the working process of the entire device, and the contents not described in detail in this specification belong to the existing technology known to professional and technical personnel in this field.

[0037] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A welding machine for processing stainless steel pipe fittings, comprising a machine body (1), wherein a vertical plate (2) is provided on the upper surface of the machine body (1), and a motor (3) is connected to the surface of the vertical plate (2) by bolts, and a mechanical arm is provided on the upper surface of the machine body (1), and the machine body (1) completes welding by the mechanical arm, and an output end of the motor (3) is fixedly connected to a connecting shaft (5); Its characteristics are: A circular plate (6) is provided on the inner side of the vertical plate (2), and a lower clamping plate (7) is fixedly connected to the inner side of the circular plate (6), and the lower clamping plate (7) is connected to the upper clamping plate (8) via a snap-fit mechanism; A support block (18) is provided on the upper surface of the machine body (1), and a long pin (9) is rotatably provided inside the support block (18), and a sliding frame (21) is movably provided inside the support block (18), and the sliding frame (21) is connected to a cleaning plate (26) via a swing mechanism; A docking plate (32) is fixedly connected to the upper surface of the body (1), and an airbag (33) is bonded to the surface of the docking plate (32); The upper surface of the cleaning plate (26) is provided with a long plate (29), and the lower surface of the long plate (29) is fixedly connected with a nozzle (31).

2. A welding machine for processing stainless steel pipes and fittings according to claim 1, characterized in that: The connecting shaft (5) is fixedly connected to the circular plate (6), and the circular plates (6) are symmetrically distributed on both sides of the body (1). The upper surface of the body (1) is fixedly connected to a support plate (4), and a ball is rotatably provided inside the support plate (4). The surface of the ball fits the surface of the circular plate (6). The end of one side of the lower splint (7) and the end of one side of the upper splint (8) are connected by a hinge. The locking mechanism includes a fixed block (10) fixedly connected to the surface of the upper splint (8), and also includes a connecting block (11) fixedly connected to the surface of the lower splint (7).

3. A welding machine for processing stainless steel pipes and fittings according to claim 2, characterized in that: The lower surface of the fixed block (10) is fixedly connected to an auxiliary plate (13), and a card slot (14) is provided on both the left and right sides of the auxiliary plate (13). A card block (12) corresponding to the card slot (14) is slidably provided inside the connecting block (11), and the outer end of the card block (12) is convex, and the inner surface of the card block (12) is inclined.

4. A welding machine for processing stainless steel pipes and fittings according to claim 3, characterized in that: A first spring (15) is fixedly connected to a raised position at the end of the clamping block (12), and the other side of the first spring (15) is fixedly connected to the inner wall of the connecting block (11). A push rod (16) is slidably provided inside the connecting block (11), and a second spring (17) is fixedly connected between the lower surface of the push rod (16) and the connecting block (11).

5. The welding machine for processing stainless steel pipes and fittings according to claim 1, characterized in that: The connecting shaft (5) is connected to the long pin (9) via a pulley, a slider (20) is fixedly connected to the upper surface of the sliding frame (21), and tooth blocks (22) are arranged at equal intervals on the inner wall of the sliding frame (21), a limiting rod (19) is fixedly connected to the inner wall of the support block (18), and the limiting rod (19) is an inverted "U" shape when viewed from above, and the surface of the limiting rod (19) is sleeved with the slider (20).

6. The welding machine for processing stainless steel pipes and pipe fittings according to claim 5, characterized in that: The swing mechanism includes a working gear (23) fixedly connected to the end of the long pin (9), and the working gear (23) is a non-full gear structure, and the working gear (23) is meshed and connected with the tooth block (22), and the lower surface of the sliding frame (21) is fixedly connected with a lower connecting block (25).

7. The welding machine for processing stainless steel pipes and pipe fittings according to claim 6, characterized in that: An inner connecting plate (27) is slidingly provided inside the lower connecting block (25), and a groove (28) is provided on the upper surface of the inner connecting plate (27). An auxiliary rod (24) is fixedly connected to the inner wall of the supporting block (18), and the front view of the auxiliary rod (24) is an inverted "L" structure.

8. The welding machine for processing stainless steel pipes and pipe fittings according to claim 7, characterized in that: The end of the auxiliary rod (24) is located inside the groove (28), and the groove (28) is curved. The cleaning plate (26) is inserted inside the inner plate (27).

9. The welding machine for processing stainless steel pipes and pipe fittings according to claim 1, characterized in that: A delivery pipe (30) is fixedly connected to the surface of the long plate (29), an air inlet pipe is fixedly connected to the left side of the air bag (33), and an air outlet pipe is fixedly connected to the right side of the air bag (33), and the air outlet pipe is connected to the delivery pipe (30) via an external hose.

10. The welding machine for processing stainless steel pipes and fittings according to claim 9, characterized in that: The ends of the delivery pipes (30) are located on the lower side of the cleaning plate (26), and an inclined guide plate is provided on the upper surface of the cleaning plate (26), and the delivery pipes (30) are distributed at equal intervals on the lower surface of the long plate (29).

Images