Blowing dust removal device for impressing roller
By designing an imprint roller air blow dust removal device including vacuuming and blowing components, the problem of contamination and temperature increase in the printing process is solved, effective cleaning and cooling effects are achieved, and the service life of the printing equipment is extended.
Patent Information
- Application Number
- CN202422209019.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2025-06-03
- Estimated Expiration
- 2034-09-09
AI Technical Summary
In the printing process, the imprinting roller may be contaminated by dust, impurities, etc., resulting in surface potholes or knife wires forming, affecting the quality of the printed product. At the same time, the use of the rubber imprinting roller under high pressure will cause temperature rise and aging, shortening its service life.
An imprint roller air blow dust removal device is designed, including a left bracket, a right bracket, an imprint roller body, a plate roller, a vacuum cleaner assembly and an air blow assembly. The vacuum cleaner assembly forms negative pressure through the left vacuum cleaner and the right vacuum cleaner to absorb debris on the roller body; the air blowing assembly blows gas through the left air blowing pipe and the right air blowing pipe to form an air flow to clean the surface of the roller body, and cool the air through a heat exchanger.
Effectively clean impurities on the surface of the imprint roller, prevent potholes and cutters from forming, extending service life, and at the same time, increasing heat loss by accelerating air flow and cooling to extend the service life of the roller body.
Smart Images
Figure CN222933552U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of printing equipment, and particularly relates to a blowing and dust-removing device for an impression roller. Background Art
[0002] In the printing process, as a core component, the impression roller mainly contacts the printing substrate during printing, and transfers the ink to the printing substrate through the patterns or textures on its surface to form the required graphic information. This process not only requires the impression roller to have high precision and stability, but also needs to ensure that its surface is clean and free of dirt to fully guarantee the final quality of the printed matter. However, during the printing production process, the impression roller may be affected by various pollution sources, including dust in the workshop environment, impurities in the raw materials, etc. These pollution sources may adhere to the surface of the impression roller through air flow, ink transfer or mechanical contact. If not cleaned for a long time, these pollutants will stick tightly to the surface of the impression roller and cause pitting, or these pollutants will fall into the ink tank to form wire drawing, seriously affecting the product quality of the printed matter. At the same time, the impression roller contacts the printing plate and paper under high pressure for a long time, which causes the temperature of the rubber impression roller to rise, resulting in rubber aging and shortening the service life of the impression roller. Content of the Utility Model
[0003] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a blowing and dust-removing device for an impression roller that can clean the surface of the printing plate roller and cool the surface of the impression roller at the same time.
[0004] To solve the above technical problem, the technical solution adopted by the utility model is: to provide a blowing and dust-removing device for an impression roller, which includes a left bracket, a right bracket, an impression roller body and a printing plate roller installed between the left bracket and the right bracket, and further includes a dust suction component. The dust suction component includes a left dust suction pipe and a right dust suction pipe arranged on the left bracket and the right bracket. The ends of the left dust suction pipe and the right dust suction pipe facing the impression roller body are respectively provided with a left dust suction nozzle and a right dust suction nozzle; above the impression roller body, a blowing component for blowing air to the impression roller body is arranged between the left bracket and the right bracket along the length direction of the impression roller body. The blowing component is distributed along the length direction of the impression roller body, and the length of the blowing component is adapted to the length of the printing roller body.
[0005] Further, the opposite surfaces of the left dust suction nozzle and the right dust suction nozzle are respectively formed with a left inclined surface and a right inclined surface. Both the left inclined surface and the right inclined surface are inclined from the bottom to the top in opposite directions, and a plurality of dust suction holes are arranged on both the left inclined surface and the right inclined surface.
[0006] Further, the air blowing assembly includes a left air blowing pipe connected to the left dust suction nozzle, a right air blowing pipe connected to the right dust suction nozzle, and a connecting pipe group connected between the left air blowing pipe and the right air blowing pipe. A plurality of left air blowing holes and right air blowing holes are respectively arranged on the left air blowing pipe and the right air blowing pipe along their respective lengths. Each left air blowing hole is arranged to incline downward and to the left, and each right air blowing hole is arranged to incline downward and to the right.
[0007] Further, the connecting pipe group includes two side pipelines and a middle pipeline arranged therebetween. The middle pipeline is communicated with the right air blowing pipe, and a plurality of right inclined holes are formed in the middle pipeline. Both of the two side pipelines are communicated with the left air blowing pipe, and a plurality of left inclined holes are formed in both of the two side pipelines.
[0008] Further, a first opening and a second opening are respectively arranged on the left dust suction pipe and the right dust suction pipe. A first elbow and a second elbow are respectively fixedly connected to the first opening and the second opening. The opposite ends of the first elbow and the second elbow respectively extend into the left dust suction pipe and the right dust suction pipe, and are respectively communicated with the left air blowing pipe and the right air blowing pipe. The opposite ends of the first elbow and the second elbow away from each other are respectively connected with a first air blowing device and a second air blowing device through connecting pipes.
[0009] Further, a left support seat and a right support seat are respectively slidably connected to the left support and the right support. The plate cylinder is rotatably connected between the left support seat and the right support seat.
[0010] Further, a first insertion slot and a second insertion slot for inserting the left support and the right support are respectively arranged on the left support seat and the right support seat. The first insertion slot and the second insertion slot respectively penetrate through the left and right sides of the left support seat and the right support seat. Two track bars are respectively fixedly connected to the front and rear sides of the left support and the right support. Two track slots adapted to the two track bars are respectively formed on the front and rear side walls of the first insertion slot and the second insertion slot. The four track bars are respectively slidably connected to the four track slots.
[0011] Further, lower connecting frames are respectively fixedly connected to the two outer sides of the left support seat and the right support seat. Upper connecting frames adapted to the lower connecting frames are respectively fixedly connected to the outer sides of the left support and the right support. A pressure adjusting assembly for adjusting the pressure between the impression cylinder body and the plate cylinder is arranged between the upper connecting frame and the lower connecting frame.
[0012] Further, the pressure regulating assembly includes a bolt rod, a spring and a threaded sleeve. The bolt rod is disposed through the lower connecting frame from bottom to top. One end of the threaded sleeve is threadedly connected to the bolt rod, and the other end of the threaded sleeve is disposed through the upper connecting frame. A limiting portion with an outer diameter larger than the outer diameter of the threaded sleeve is formed at one end of the threaded sleeve close to the bolt rod. A limiting plate for preventing the threaded sleeve from disengaging from the upper connecting frame is disposed at the other end of the threaded sleeve away from the limiting portion. The spring is sleeved outside the threaded sleeve, and two ends of the spring respectively abut against the limiting portion and the upper connecting frame.
[0013] Further, a section of the threaded sleeve away from the limiting portion is a rectangular tube with a rectangular cross-section, and a rectangular through hole for the rectangular tube to pass through is disposed on the upper connecting frame.
[0014] A stamping roller air blowing and dust removing device of the present utility model forms a relative action with respect to the stamping roller body by feeding gas into the left air blowing pipe and the right air blowing pipe, and the gas is discharged through the left inclined holes and the right inclined holes. A stronger air flow forms the cleaning of the surface of the stamping roller body. Meanwhile, negative pressure adsorption is formed with respect to the stamping roller body through the left dust suction nozzle and the right dust suction nozzle, so as to realize the adsorption and cleaning of the sundries on the stamping roller body blown up by the gas flow in the previous link. During this process, the air flow efficiency on the surface of the stamping roller body is also improved. Therefore, the heat dissipation on the surface of the stamping roller body can be accelerated, and the air cooled by the heat exchanger with a cooling function is fed into the left air blowing pipe and the right air blowing pipe, which can further cool the stamping roller body while realizing the basic auxiliary cleaning of the stamping roller body. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 is the overall structural schematic diagram of an embodiment of the present utility model.
[0016] Figure 2 is the connection structural schematic diagram of the left bracket and the left support seat in the present utility model.
[0017] Figure 3 is the connection structural schematic diagram of the bolt rod, the threaded sleeve and the spring in the present utility model.
[0018] Figure 4 is the structural schematic diagram of the left dust suction nozzle and the right dust suction nozzle of an embodiment of the present utility model.
[0019] Figure 5 is the partial sectional structural schematic diagram of the air blowing assembly in an embodiment of the present utility model.
[0020] The meanings of the reference numerals in the drawings are as follows: left support 1; left support base 11; first insertion slot 111; right support 2; right support base 21; second insertion slot 211; embossing roller body 3; printing plate roller 4; dust suction assembly 5; left dust suction pipe 51; first opening 511; first elbow 512; right dust suction pipe 52; second opening 521; second elbow 522; left dust suction nozzle 53; left inclined surface 531; right dust suction nozzle 54; right inclined surface 541; air blowing assembly 6; left air blowing pipe 61; left air blowing hole 611; right air blowing pipe 62; right air blowing hole 621; connecting pipe group 63; side pipeline 631; left inclined hole 6311; middle pipeline 632; right inclined hole 6321; first air blowing device 7; second air blowing device 8; track bar 9; track groove 91; pressure regulating assembly 10; bolt rod 101; spring 102; threaded sleeve 103; limiting portion 1031; limiting plate 1032; rectangular cylinder 1033; lower connecting frame a; upper connecting frame b; rectangular through hole b1. Detailed implementation manners
[0021] The following is a further detailed description through specific implementation manners:
[0022] Please refer to Figure 1 、 Figure 2 and Figure 3 As shown in, and, a blowing and dust removing device for an embossing roller of the present utility model includes a left support 1, a right support 2, and an embossing roller body 3 and a printing plate roller 4 installed between the left support 1 and the right support 2. It further includes a dust suction assembly 5. The dust suction assembly 5 includes a left dust suction pipe 51 and a right dust suction pipe 52 provided on the left support 1 and the right support 2. Left dust suction nozzles 53 and right dust suction nozzles 54 are respectively provided at one ends of the left dust suction pipe 51 and the right dust suction pipe 52 facing the embossing roller body 3. An air blowing assembly 6 for blowing air to the embossing roller body 3 is arranged between the left support 1 and the right support 2 above the embossing roller body 3 along the length direction of the embossing roller body 3. The air blowing assembly 6 is distributed along the length direction of the embossing roller body 3, and the length of the air blowing assembly 6 is adapted to the length of the printing roller body 3. Through the air blowing assembly 6, a blowing effect is formed relative to the embossing roller body 3. During the gas flow process, a strong air flow forms a cleaning of the surface of the embossing roller body 3 and can also accelerate the removal of the heat on the surface of the embossing roller body 3 to cool the embossing roller body 3; at the same time, a negative pressure adsorption is formed relative to the embossing roller body 3 through the left dust suction nozzles 53 and the right dust suction nozzles 54, so as to realize the adsorption and cleaning of the sundries on the embossing roller body 3 blown up by the gas flow in the previous link.
[0023] Please continue to refer to Figure 4 and Figure 5, for the convenience of the installation and disassembly of the overall device, the left support base 11 and the right support base 21 are respectively slidably connected to the left bracket 1 and the right bracket 2. The plate cylinder 4 is rotatably connected between the left support base 11 and the right support base 21, and the impression roller body 3 is rotatably connected between the left bracket 1 and the right bracket 2 and above the plate cylinder 4. Specifically, first insertion slots 111 and second insertion slots 211 into which the left bracket 1 and the right bracket 2 are inserted are respectively provided on the left support base 11 and the right support base 21. The first insertion slots 111 and the second insertion slots 211 respectively penetrate through the left and right sides of the left support base 11 and the right support base 21. Two track bars 9 are fixedly connected to the front and rear sides of the left bracket 1 and the right bracket 2. Two track grooves 91 adapted to the two track bars 9 are respectively formed on the front and rear side walls of the first insertion slots 111 and the second insertion slots 211. The four track bars 9 are respectively slidably connected to the four track grooves 91. During installation, first, the left support base 11 and the right support base 21 are locked and fixed by bolts, and then the left bracket 1 and the right bracket 2 are inserted into the first insertion slots 111 and the second insertion slots 211. In this embodiment, the cross sections of the four track bars 9 and the four track grooves 91 are both swallowtail-shaped. Through this design, the accuracy and stability of the movement of mechanical components can be ensured, and loosening and shaking are not likely to occur.
[0024] During the printing process, due to different printing materials, different printing materials need to withstand different pressures, otherwise it may affect the quality of the printed matter. In order to change the pressure between the impression cylinder 3 and the printing plate cylinder 4 to suit printing items of different materials, lower connecting frames a are fixedly connected to both outer sides of the left support base 11 and the right support base 21. Upper connecting frames b adapted to the lower connecting frames a are fixedly connected to the outer sides of the left bracket 1 and the right bracket 2. A pressure adjusting assembly 10 for adjusting the pressure between the impression cylinder 3 and the printing plate cylinder 4 is provided between the upper connecting frame b and the lower connecting frame a. Specifically, the pressure adjusting assembly 10 includes a bolt rod 101, a spring 102, and a threaded sleeve 103. The bolt rod 101 is inserted into the lower connecting frame a from bottom to top. One end of the threaded sleeve 103 is threadedly connected to the bolt rod 101, and the other end of the threaded sleeve 103 is inserted into the upper connecting frame b. A limiting portion 1031 with an outer diameter larger than the outer diameter of the threaded sleeve 103 is formed at one end of the threaded sleeve 103 close to the bolt rod 101. A limiting plate 1032 for preventing the threaded sleeve 103 from disengaging from the upper connecting frame b is provided at the end of the threaded sleeve 103 far from the limiting portion 1031. The spring 102 is sleeved outside the threaded sleeve 103, and both ends of the spring 102 are respectively abutted against the limiting portion 1031 and the upper connecting frame b. When in use, after fixing the threaded sleeve 103 and rotating the bolt rod 101, the corresponding adjustment of the height of the threaded sleeve 103 on the bolt rod 101 can be realized. Since the distance between the corresponding upper and lower connecting frames a and b is the overall height formed by the cooperation of the spring 102, the threaded sleeve 103, and the bolt rod 101, by adjusting the relative position of the threaded sleeve 103 relative to the bolt rod 101, the insertion height of the spring 102 between the limiting portion 1031 and the upper connecting frame 18 can be controlled. By adjusting the stretch of the spring 102, the supporting force provided by the spring 102 can be changed, thereby achieving the adjustment of the relative pressure between the impression cylinder 3 and the printing plate cylinder 4 to suit different printing materials. Since the threaded sleeve 103 is inserted into the upper connecting frame b, during the movement of the threaded sleeve 103, the limiting plate 1032 can prevent the threaded sleeve 103 from disengaging from the upper connecting frame b and affecting the acting force of the spring 102. When the threaded sleeve 103 moves to the limit position, the limiting plate 1032 will abut against the upper surface of the upper connecting frame b to prevent the threaded sleeve 103 from moving further. Specifically, the limiting plate 1032 is fixedly connected to the threaded sleeve 103 by bolts, so it will not affect the overall disassembly and installation. For more convenient use, a rectangular tube 1033 with a rectangular cross-section is designed at the end of the threaded sleeve 103 far from the limiting portion 1031. At the same time, a rectangular through-hole b1 for the rectangular tube 1033 to pass through is provided on the upper connecting frame b.With this design, when the bolt rod 101 is rotated, due to the restriction of the rectangular perforation b1 on the rectangular cylinder 1033, the threaded sleeve 103 cannot rotate with the bolt rod 101 when adjusting the rotation of the bolt rod 101. The threaded sleeve 103 can only move up and down. Therefore, when in use, there is no need to manually fix the threaded sleeve 103. Only by rotating the bolt rod 101 can the adjustment be completed, which is more convenient to use.
[0025] In order to enable the left suction nozzle 53 and the right suction nozzle to better adsorb the impurities on the impression roller body 3, a left inclined surface 531 and a right inclined surface 541 are respectively formed on the opposite surfaces of the left suction nozzle 53 and the right suction nozzle 54. The left inclined surface 531 and the right inclined surface 541 are both inclined from the bottom to the top in the opposite direction. A plurality of suction holes are provided on both the left inclined surface 531 and the right inclined surface 541. With this design, the left suction nozzle 53 and the right suction nozzle 54 can be made to face the surface of the impression roller body 3 as much as possible. In this embodiment, the blowing assembly 6 includes a left blowing pipe 61 connected to the left suction nozzle 53, a right blowing pipe 62 connected to the right suction nozzle 54, and a connecting pipe group 63 connected between the left blowing pipe 61 and the right blowing pipe 62. First openings 511 and second openings 521 are respectively provided on the left suction pipe 51 and the right suction pipe 52. A first elbow 512 and a second elbow 522 are respectively fixedly connected to the first opening 511 and the second opening 521. The opposite ends of the first elbow 512 and the second elbow 522 respectively extend into the left suction pipe 51 and the right suction pipe 52 and are respectively communicated with the left blowing pipe 61 and the right blowing pipe 62. The opposite ends of the first elbow 512 and the second elbow 522 away from each other are respectively connected with a first blowing device 7 and a second blowing device 8 through connecting pipes. The first blowing device 7 and the second blowing device 8 are respectively fixed on the left support seat 11 and the right support seat 12. In order to cool the outer surface of the impression roller body 3, in this embodiment, heat exchangers are provided in both the first blowing device 7 and the second blowing device 8. The cooled air is blown out from the left blowing pipe 61 and the right blowing pipe 62 by using the heat exchangers. The gas blown out from the left blowing pipe 61 and the right blowing pipe 62 can accelerate the dissipation of the heat on the surface of the impression roller body 3. Coupled with the cooled air, it can further enhance the cooling treatment of the impression roller body 3.
[0026] Since the left suction nozzle 53 and the right suction nozzle 54 are located on both sides of the embossing roller body 3, in order to facilitate the adsorption of the left suction nozzle 53 and the right suction nozzle 54, a plurality of left blowing holes 611 and right blowing holes 621 distributed along their respective lengths are respectively provided on the left blowing pipe 61 and the right blowing pipe 62. Each left blowing hole 611 is arranged to incline downward and to the left, and each right blowing hole 621 is arranged to incline downward and to the right. During use, the left blowing holes 611 blow air towards the direction of the left suction nozzle 53, and the right blowing holes 621 blow air towards the direction of the right suction nozzle 54. The blowing path can be changed through the left blowing holes 611 and the right blowing holes 621, so that the blown air is directed towards both sides, thereby blowing the impurities towards the left and right sides to facilitate the adsorption of the left suction nozzle 53 and the right suction nozzle 54. During this process, the middle part of the printing roller body 3 cannot be covered, which will cause debris to remain. The solution given in this embodiment is that two side pipelines 631 and a middle pipeline 632 arranged therein are provided in the connecting pipe group 63. The middle pipeline 632 is communicated with the right blowing pipe 62, and a plurality of right inclined holes 6321 are opened on the middle pipeline 632. Both side pipelines 631 are communicated with the left blowing pipe 61, and a plurality of left inclined holes 6311 are opened on both side pipelines 631. Through this design, the blowing and dust removal operation on the area between the left blowing pipe 61 and the right blowing pipe 62 on the embossing roller body 3 is realized, so that the intersection between the right blowing holes 111 and the left blowing holes 101 can be well covered, and the area on the embossing roller body 3 that cannot be cleaned by blowing and dust removal is reduced. At the same time, a plurality of left inclined holes 6311 and a plurality of right inclined holes 6321 are arranged at intervals alternately, improving the covering effect of the left inclined holes 6311 and the right inclined holes 6321 relative to the middle area on the embossing roller body 3, enabling it to be completely covered without any area that cannot be cleared, which is more reasonable.
[0027] The above are only the embodiments of the present invention, and common knowledge such as specific structures and characteristics known in the solutions is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can still be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the present invention.
Claims
1. An air blowing dust removal device for an embossing roller, comprising a left bracket, a right bracket, and an embossing roller body and a printing plate roller installed between the left bracket and the right bracket, characterized in that: It also includes a dust suction component, which includes a left dust suction pipe and a right dust suction pipe arranged on the left bracket and the right bracket, and the left dust suction pipe and the right dust suction pipe are respectively provided with a left dust suction nozzle and a right dust suction nozzle at one end facing the embossing roller body; a blowing component for blowing air to the embossing roller body is provided above the embossing roller body along the length direction of the embossing roller body and is located between the left bracket and the right bracket, the blowing component is distributed along the length direction of the embossing roller body, and the length of the blowing component is adapted to the length of the embossing roller body.
2. The air blowing dust removal device for the embossing roller according to claim 1, characterized in that: The opposite surfaces of the left dust suction nozzle and the right dust suction nozzle are respectively formed with a left inclined surface and a right inclined surface, and the left inclined surface and the right inclined surface are both inclined in opposite directions from the bottom to the top, and a plurality of dust suction holes are arranged on the left inclined surface and the right inclined surface.
3. The air blowing dust removal device for the embossing roller according to claim 1, characterized in that: The air blowing assembly includes a left air blowing pipe connected to the left dust suction nozzle, a right air blowing pipe connected to the right dust suction nozzle, and a connecting pipe group connected between the left air blowing pipe and the right air blowing pipe. The left air blowing pipe and the right air blowing pipe are respectively provided with a plurality of left air blowing holes and right air blowing holes distributed along their respective length directions. Each of the left air blowing holes is arranged downward and inclined to the left, and each of the right air blowing holes is arranged downward and inclined to the right.
4. The air blowing dust removal device for the embossing roller according to claim 3, characterized in that: The connecting pipe group includes two side pipes and a middle pipe arranged therebetween, the middle pipe is connected to the right air blowing pipe, a plurality of right inclined holes are opened on the middle pipe, the two side pipes are connected to the left air blowing pipe, and a plurality of left inclined holes are opened on the two side pipes.
5. The air blowing dust removal device for the embossing roller according to claim 3, characterized in that: The left dust suction pipe and the right dust suction pipe are respectively provided with a first opening and a second opening, and the first opening and the second opening are respectively fixedly connected with a first elbow and a second elbow, and the ends opposite to each other of the first elbow and the second elbow extend into the left dust suction pipe and the right dust suction pipe, respectively, and are respectively connected with the left air blowing pipe and the right air blowing pipe, and the ends of the first elbow and the second elbow away from each other are respectively connected with a first air blowing device and a second air blowing device through a connecting pipe.
6. The air blowing dust removal device for the embossing roller according to claim 1, characterized in that: The left bracket and the right bracket are respectively slidably connected to a left supporting seat and a right supporting seat, and the printing plate roller is rotatably connected between the left supporting seat and the right supporting seat.
7. The air blowing dust removal device for the embossing roller according to claim 6, characterized in that: The left support seat and the right support seat are respectively provided with a first plugging slot and a second plugging slot for inserting the left bracket and the right bracket, the first plugging slot and the second plugging slot respectively penetrate the left and right sides of the left support seat and the right support seat, the front and rear sides of the left bracket and the right bracket are fixedly connected with two track bars, the front and rear side walls of the first plugging slot and the second plugging slot are respectively provided with two track grooves adapted to the two track bars, and the four track bars are respectively slidably connected with the four track grooves.
8. The air blowing dust removal device for the embossing roller according to claim 7, characterized in that: The outer sides of the left support seat and the right support seat are fixedly connected with lower connecting frames, and the outer sides of the left bracket and the right bracket are fixedly connected with upper connecting frames adapted to the lower connecting frames, and a pressure regulating component for regulating the pressure between the stamping roller body and the printing plate roller is arranged between the upper connecting frame and the lower connecting frame.
9. The air blowing dust removal device for the embossing roller according to claim 8, characterized in that: The pressure regulating assembly includes a bolt rod, a spring and a threaded sleeve, the bolt rod is inserted into the lower connecting frame from bottom to top, one end of the threaded sleeve is threadedly connected to the bolt rod, and the other end of the threaded sleeve is inserted into the upper connecting frame, and a limiting portion with an outer diameter larger than the outer diameter of the threaded sleeve is formed at one end of the threaded sleeve close to the bolt rod, and a limiting plate is provided at one end of the threaded sleeve away from the limiting portion to prevent the threaded sleeve from being separated from the upper connecting frame, the spring is sleeved outside the threaded sleeve and two ends of the spring are respectively abutted against the limiting portion and the upper connecting frame.
10. The air blowing dust removal device for the embossing roller according to claim 9, characterized in that: A section of the threaded sleeve away from the limiting portion is a rectangular tube with a rectangular cross section, and the upper connecting frame is provided with a rectangular through hole for the rectangular tube to pass through.