A multiplex PCR quantitative detector

Abstract

The present invention relates to the field of PCR detection, and particularly to a multiplex PCR quantitative detector, which includes a quantitative detector and a placement table extending at the front end of the quantitative detector. A lower push seat and an upper push seat are respectively slidably installed at the rear part of the upper end of the placement table. The upper push seat is located above the lower push seat, and the upper push seat is elastically connected to the lower push seat. A sliding sleeve is slidably installed on the side surface of the lower push seat, and a push frame is rotatably installed between the upper end of the sliding sleeve and one side of the upper push seat. A fixing frame is fixedly installed near the edge of the upper end of the placement table, a bag supporting member is arranged on the fixing frame, and two L-shaped seats are symmetrically arranged on the side surface of the fixing frame. The present invention can adapt to the sample liquid in the bag for detection, effectively meets the use requirements, and avoids the phenomenon that the sample liquid in the bag continuously discharges and overflows the disposable tray to contaminate the equipment.

Description

Technical Field

[0001] The present invention relates to the field of PCR detection, and particularly to a multiplex PCR quantitative detector. Background Art

[0002] Multiplex PCR quantitative detection is based on ordinary PCR technology, but multiple pairs of specific primers are added to the same reaction system. These primers can specifically bind to different regions of the template DNA, so as to amplify multiple target fragments in the same reaction. Combining detection means such as fluorescent probes or fluorescent dyes can achieve real-time quantitative detection of multiple targets.

[0003] When the detection device is working, the detection pipette in the device will extend and move downward to insert into the sample solution to aspirate the sample solution so that it enters the device for detection. For some volatile or easily contaminated samples, using a bag with good sealing performance for encapsulation can effectively prevent the volatilization or contamination of the sample and ensure the integrity of the sample. However, there are drawbacks in detecting bagged samples. The sample solution is wrapped by the bag body, making it difficult for the detection device to aspirate the sample solution, that is, the phenomenon of unable to detect occurs, so it is difficult to meet the usage requirements. Summary of the Invention

[0004] The purpose of the present invention is to solve the drawbacks existing in the background art, and a multiplex PCR quantitative detector is proposed.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: a multiplex PCR quantitative detector, including a quantitative detector and a placement table extending at the front end of the quantitative detector. A lower push seat and an upper push seat are respectively and slidably installed at the rear part of the upper end of the placement table. The upper push seat is located above the lower push seat, and the upper push seat is elastically connected to the lower push seat. A sliding sleeve is slidably installed on the side surface of the lower push seat. A push frame is rotatably installed between the upper end of the sliding sleeve and one side of the upper push seat. A fixing frame is fixedly installed near the edge of the upper end of the placement table. A bag supporting member is arranged on the fixing frame. Two L-shaped seats are symmetrically arranged on the side surface of the fixing frame. A pressing plate is arranged above the L-shaped seats. The pressing plate is connected to the lower push seat. A U-shaped seat is fixedly installed between the side surfaces of the two L-shaped seats. A pulling frame extends from the front end of the sliding sleeve. Three upper clamping rings are fixedly installed at the end of the pulling frame in a T-shaped distribution. A lower frame is slidably arranged below the pulling frame. The lower frame is slidably connected to the fixing frame. Three lower clamping rings are fixedly installed at the end of the lower frame in a T-shaped distribution.

[0006] Preferably, an extending frame is fixedly installed between the lower ends of the two L-shaped seats. The end of the extending frame is fixed to the fixing frame. A plate frame is fixedly installed at the upper end of the pressing plate. The end of the plate frame is fixed to the lower push seat. A square frame is slidably installed through the inside of the sliding sleeve. The square frame penetrates out from both sides of the sliding sleeve. The end of the square frame is fixed to the lower push seat.

[0007] Preferably, a carrier is fixedly installed at the rear part of the upper end of the storage table. Two second groove columns are symmetrically and fixedly installed at the upper end of the carrier. The upper push seat and the lower push seat are slidably installed on the surface of the second groove columns. A spring body is wound around the outer side of the second groove columns. One end of the spring body is fixed to the lower end of the upper push seat, and the other end of the spring body is fixed to the upper end of the lower push seat.

[0008] Preferably, a servo push cylinder is fixedly installed at the lower end of the storage table. A pull rod is fixedly installed at the output end of the servo push cylinder. The pull rod sequentially passes through the storage table, the carrier, and the lower push seat. The pull rod is slidably connected to the storage table, the carrier, and the lower push seat. The upper push seat is embedded at the end of the pull rod. Arc-shaped positioning edges extend at the corners of the upper end of the storage table. Anti-slip patterns are provided on the opposite surfaces of the L-shaped seat and the pressing plate.

[0009] Preferably, a synchronous column is fixedly installed at the rear end of the lower frame. The pulling frame is slidably installed on the outer surface of the synchronous column. A guide frame is fixedly installed at the lower end of the lower frame. A guide sleeve is slidably installed on the outer surface of the guide frame. The end of the guide sleeve is fixed to the fixed frame.

[0010] Preferably, the bag supporting member includes a plate shaft rotatably installed at the end of the fixed frame. A bag supporting plate is embedded on the outer surface of the plate shaft. The bag supporting plate inclines downward. Two limiting edges symmetrically extend at the upper end of the bag supporting plate.

[0011] Preferably, a gear is coaxially embedded at the rear end of the plate shaft. A toothed plate is meshed with the side of the gear. The toothed plate is elastically connected to the fixed frame. A push claw is arranged above the toothed plate. The end of the push claw is fixed to the other side of the upper push seat.

[0012] Preferably, a first groove column is fixedly installed in the middle of the toothed plate. A column frame is slidably installed on the outer surface of the first groove column. The end of the column frame is fixed to the fixed frame. A return spring is wound around the outer side of the first groove column. The upper end of the return spring is fixed to the toothed plate, and the lower end of the return spring is fixed to the upper end of the column frame. A column cap is coaxially embedded at the lower end of the first groove column. The column cap fits against the lower end of the column frame.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. Place the bag body on the bag support plate. At this time, the bottom of the bag body is located at the L-shaped seat, the discharge pipe is located in the U-shaped seat, and the pipe plug is located in the lower clamping ring. Then, the upper push seat moves downward, and through the spring body, it pushes the lower push seat, enabling the pressing plate and the upper clamping ring on the lower push seat to move downward. The pressing plate is used to clamp and fix the bottom of the bag body on the L-shaped seat, and at the same time, the upper clamping ring fixes the pipe plug in the lower clamping ring. Subsequently, the upper push seat continues to move downward. At this time, supported by the L-shaped seat and the lower clamping ring, the lower push seat will remain stationary, while the continuously descending upper push seat will drive the push frame to move, causing the sliding sleeve to slide on the square frame, thereby driving the fixed pipe plug to move laterally and pulling the pipe plug out of the discharge pipe on the bag body, allowing the sample liquid in the bag body to flow into the disposable tray through the discharge pipe and be sucked by the quantitative detector for detection, so as to adapt to the detection of the sample liquid in the bag body and meet its usage requirements.

[0015] 2. Under the action of the bag support plate being inclined downward, the sample liquid in the bag body can be gathered at the top of the bag body. After the pipe plug is pulled out, the push claw on the upper push seat just contacts the toothed plate. At this time, the upper push seat continues to move downward, causing the push claw to push the toothed plate, flipping the gear, and then driving the bag support plate to slowly turn upward, enabling the sample liquid in the bag body to flow to the discharge pipe for discharge, thereby achieving the purpose of controlling the discharge of the sample liquid and avoiding the continuous discharge of the sample liquid in the bag body from overflowing the disposable tray and contaminating the equipment. Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of a multiplex PCR quantitative detector of the present invention;

[0017] Figure 2 It is a schematic diagram of the bag support plate of a multiplex PCR quantitative detector of the present invention;

[0018] Figure 3 It is a schematic diagram of the L-shaped seat of a multiplex PCR quantitative detector of the present invention;

[0019] Figure 4 It is a schematic diagram of the synchronous column of a multiplex PCR quantitative detector of the present invention;

[0020] Figure 5 It is another perspective schematic diagram of the bag support plate of a multiplex PCR quantitative detector of the present invention;

[0021] Figure 6 It is a schematic diagram of the gear of a multiplex PCR quantitative detector of the present invention;

[0022] Figure 7 It is a schematic diagram of the placement table of a multiplex PCR quantitative detector of the present invention;

[0023] Figure 8 It is a placement view of the bag body of a multiplex PCR quantitative detector of the present invention;

[0024] Figure 9 Schematic diagram of the bag body of a multiplex PCR quantitative detector of the present invention.

[0025] In the figure: 1. Quantitative detector; 2. Object placing table; 3. Bag supporting plate; 4. Limiting edge; 5. Fixed frame; 6. Plate shaft; 7. Extending frame; 8. L-shaped seat; 9. Pressing plate; 10. Plate frame; 11. Lower pushing seat; 12. Pushing claw; 13. Sliding sleeve; 14. Pulling frame; 15. Synchronous column; 16. Lower clamping ring; 17. Anti-slip pattern; 18. U-shaped seat; 19. Disposable receiving tray; 20. Guide sleeve; 21. Guide frame; 22. Lower frame; 23. First groove column; 24. Column cap; 25. Upper clamping ring; 26. Column frame; 27. Return spring; 28. Gear; 29. Servo push cylinder; 30. Pull rod; 31. Carrying frame; 32. Second groove column; 33. Square frame; 34. Pushing frame; 35. Upper pushing seat; 36. Spring body; 37. Arc-shaped positioning edge; 38. Tooth plate; 39. Bag body; 40. Discharge pipe; 41. Pipe plug. Specific embodiments

[0026] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations.

[0027] Such as Figures 1-9A multiple PCR quantitative detector shown in the figure includes a quantitative detector 1 and a placement table 2 extending at the front end of the quantitative detector 1. The detection pipette in the quantitative detector 1 extends out and moves down to insert into the sample solution to aspirate the sample solution and make it enter the inside of the quantitative detector 1 for detection. Since this kind of detection operation is an existing technology and has been widely used, it is not elaborated in detail here. A lower push seat 11 and an upper push seat 35 are slidably installed at the rear part of the upper end of the placement table 2. The upper push seat 35 is located above the lower push seat 11, and the upper push seat 35 is elastically connected to the lower push seat 11. A sliding sleeve 13 is slidably installed on the side of the lower push seat 11. The sliding sleeve 13 can drive the pulling frame 14 to move sideways to pull out the tube plug 41 from the discharge pipe 40 on the bag body 39. A push frame 34 is rotatably installed between the upper end of the sliding sleeve 13 and one side of the upper push seat 35. The push frame 34 can move under the drive of the upper push seat 35 to push the sliding sleeve 13. A fixing frame 5 is fixedly installed near the edge of the upper end of the placement table 2. A bag supporting member is arranged on the fixing frame 5. The fixing frame 5 plays a role of bearing. Two L-shaped seats 8 are symmetrically arranged on the side of the fixing frame 5. A pressing plate 9 is arranged above the L-shaped seats 8. The L-shaped seats 8 and the pressing plate 9 play a role of clamping and fixing the bottom of the bag body 39. The vertical side of the L-shaped seat 8 can block the bag body 39 to prevent the bag body 39 from moving sideways. The pressing plate 9 is connected to the lower push seat 11. A U-shaped seat 18 is fixedly installed between the sides of the two L-shaped seats 8. The U-shaped seat 18 plays a role of supporting the discharge pipe 40. The front end of the sliding sleeve 13 extends with a pulling frame 14. Three upper clamping rings 25 are fixedly installed at the end of the pulling frame 14 in a T-shaped distribution. The pulling frame 14 plays a role of bearing the upper clamping rings 25. A lower frame 22 is slidably arranged below the pulling frame 14. The lower frame 22 is slidably connected to the fixing frame 5. Three lower clamping rings 16 are fixedly installed at the end of the lower frame 22 in a T-shaped distribution. The lower frame 22 plays a role of bearing the lower clamping rings 16. The lower clamping rings 16 and the upper clamping rings 25 are in a T-shaped distribution and can be clamped and fixed to adapt to the shape of the tube plug 41.

[0028] An extension frame 7 is fixedly installed between the lower ends of the two L-shaped seats 8. The end of the extension frame 7 is fixed to the fixing frame 5. The extension frame 7 plays a role of fixing the L-shaped seats 8. A plate frame 10 is fixedly installed at the upper end of the pressing plate 9. The end of the plate frame 10 is fixed to the lower push seat 11. The plate frame 10 plays a role of fixing the pressing plate 9. A square frame 33 is slidably installed through the inside of the sliding sleeve 13. The square frame 33 passes through both sides of the sliding sleeve 13. The end of the square frame 33 is fixed to the lower push seat 11. The square frame 33 plays a role of providing a sliding path for the sliding sleeve 13.

[0029] At the rear part of the upper end of the placement table 2, a carrier 31 is fixedly installed. At the upper end of the carrier 31, two second groove columns 32 are symmetrically and fixedly installed. The carrier 31 serves to support and fix the second groove columns 32. The upper pusher seat 35 and the lower pusher seat 11 are slidably installed on the surface of the second groove columns 32. The second groove columns 32 serve to allow the upper pusher seat 35 and the lower pusher seat 11 to slide. A spring body 36 is wound around the outside of the second groove columns 32. One end of the spring body 36 is fixed to the lower end of the upper pusher seat 35, and the other end of the spring body 36 is fixed to the upper end of the lower pusher seat 11. When the lower pusher seat 11 remains stationary, the spring body 36 can ensure the normal downward movement of the upper pusher seat 35.

[0030] At the lower end of the placement table 2, a servo push cylinder 29 is fixedly installed. At the output end of the servo push cylinder 29, a pull rod 30 is fixedly installed. The servo push cylinder 29 serves to drive the movement of the pull rod 30. The pull rod 30 sequentially passes through the placement table 2, the carrier 31, and the lower pusher seat 11. The pull rod 30 is slidably connected to the placement table 2, the carrier 31, and the lower pusher seat 11. The upper pusher seat 35 is embedded at the end of the pull rod 30. The pull rod 30 serves to drive the up and down movement of the upper pusher seat 35. At the corner of the upper end of the placement table 2, an arc-shaped positioning edge 37 extends. The arc-shaped positioning edge 37 can position the disposable receiving tray 19, enabling the sample liquid in the bag body 39 to flow into the disposable receiving tray 19 normally. The disposable design of the disposable receiving tray 19 can avoid sample liquid contamination. Anti-slip patterns 17 are provided on the opposite surfaces of the L-shaped seat 8 and the pressing plate 9. The anti-slip patterns 17 serve to increase the fixing force of the L-shaped seat 8 and the pressing plate 9 on the bag body 39.

[0031] At the rear end of the lower frame 22, a synchronous column 15 is fixedly installed. The pulling frame 14 is slidably installed on the outer surface of the synchronous column 15. The synchronous column 15 serves to synchronize the movement of the lower frame 22 and the pulling frame 14. At the lower end of the lower frame 22, a guiding frame 21 is fixedly installed. A guiding sleeve 20 is slidably installed on the outer surface of the guiding frame 21. The end of the guiding sleeve 20 is fixed to the fixed frame 5. The guiding frame 21 and the guiding sleeve 20 serve to guide the lower frame 22.

[0032] The bag supporting member includes a plate shaft 6 rotatably installed at the end of the fixed frame 5. A bag supporting plate 3 is embedded on the outer surface of the plate shaft 6. The plate shaft 6 serves to allow the bag supporting plate 3 to flip. The bag supporting plate 3 inclines downward, enabling the sample liquid in the bag body 39 to gather at the top of the bag body 39. At the upper end of the bag supporting plate 3, two limiting edges 4 symmetrically extend. The limiting edges 4 serve to position the bag body 39.

[0033] The rear end of the plate shaft 6 is coaxially inlaid with a gear 28. A toothed plate 38 is engaged with the side surface of the gear 28. The cooperation between the gear 28 and the toothed plate 38 can make the bag support plate 3 turn up slowly, so that the sample liquid in the bag body 39 can flow to the discharge pipe 40, and an appropriate amount of sample liquid is discharged into the disposable tray 19. The toothed plate 38 is elastically connected to the fixed frame 5. A push claw 12 is arranged above the toothed plate 38. The end of the push claw 12 is fixed to the other side of the upper push seat 35. The push claw 12 plays a role in pushing the toothed plate 38.

[0034] A first groove column 23 is fixedly installed in the middle of the toothed plate 38. The groove design on the first groove column 23 can ensure that the toothed plate 38 will not rotate. A column frame 26 is slidably installed on the outer surface of the first groove column 23. The end of the column frame 26 is fixed to the fixed frame 5. The cooperation between the column frame 26 and the first groove column 23 plays a role in guiding the toothed plate 38. A return spring 27 is wound around the outside of the first groove column 23. The upper end of the return spring 27 is fixed to the toothed plate 38, and the lower end of the return spring 27 is fixed to the upper end of the column frame 26. The return spring 27 plays a role in resetting the moved toothed plate 38. A column cap 24 is coaxially inlaid at the lower end of the first groove column 23. The column cap 24 plays a role in positioning the reset position of the toothed plate 38. The column cap 24 fits against the lower end of the column frame 26.

[0035] During detection, place the bag body 39 on the bag supporting plate 3. At this time, the bottom of the bag body 39 is located at the L-shaped seat 8, the discharge pipe 40 is located in the U-shaped seat 18, and the pipe plug 41 is located in the lower clamping ring 16. At the same time, under the action of the downward inclination of the bag supporting plate 3, the sample liquid in the bag body 39 will gather at the top of the bag body 39. Subsequently, the servo push cylinder 29 operates to drive the upper push seat 35 on the pull rod 30 to move downward, so as to push the lower push seat 11 through the spring body 36, enabling the pressing plate 9 and the upper clamping ring 25 on the lower push seat 11 to move downward, so as to clamp and fix the bottom of the bag body 39 on the L-shaped seat 8 by using the pressing plate 9. At the same time, the upper clamping ring 25 clamps the pipe plug 41 in the lower clamping ring 16 for fixation. Subsequently, the upper push seat 35 continues to move downward. At this time, supported by the L-shaped seat 8 and the lower clamping ring 16, the lower push seat 11 will remain stationary, while the continuously downward moving upper push seat 35 will drive the push frame 34 to move, causing the sliding sleeve 13 to slide on the square frame 33, thereby driving the fixed pipe plug 41 to move laterally to pull out the pipe plug 41 from the discharge pipe 40 on the bag body 39. At this time, the push claw 12 on the upper push seat 35 just contacts the toothed plate 38. Subsequently, the upper push seat 35 continues to move downward, enabling the push claw 12 to push the toothed plate 38, causing the gear 28 to flip, thereby driving the bag supporting plate 3 to slowly turn upward, allowing the sample liquid in the bag body 39 to flow to the discharge pipe 40 and discharging an appropriate amount of sample liquid into the disposable receiving tray 19. Subsequently, the upper push seat 35 moves upward to reset the bag supporting plate 3 to stop the discharge of the sample liquid in the bag body 39. Then, the detection suction pipe in the quantitative detector 1 extends and moves downward to insert into the disposable receiving tray 19 to suck the discharged sample liquid, enabling it to enter the interior of the quantitative detector 1 for detection. Subsequently, the upper push seat 35 continues to move upward to reset, and during the reset process, the pipe plug 41 is reinserted into the discharge pipe 40 and the fixation on the bag body 39 is released. Subsequently, the bag body 39 can be removed.

[0036] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A multiplex PCR quantitative detector, comprising a quantitative detector (1) and a storage platform (2) extending at the front end of the quantitative detector (1), characterized in that: A lower push seat (11) and an upper push seat (35) are slidably mounted on the rear portion of the upper end of the storage platform (2), respectively. The upper push seat (35) is located above the lower push seat (11), and the upper push seat (35) is elastically connected to the lower push seat (11). A sliding sleeve (13) is slidably mounted on the side of the lower push seat (11), and a push frame (34) is rotatably mounted between the upper end of the sliding sleeve (13) and one side of the upper push seat (35). A fixing frame (5) is fixedly mounted near the edge of the upper end of the storage platform (2), and a bag holding member is arranged on the fixing frame (5). Two symmetrical sides of the fixing frame (5) are provided. An L-shaped seat (8), a pressure plate (9) is arranged above the L-shaped seat (8), the pressure plate (9) is connected to the lower push seat (11), a U-shaped seat (18) is fixedly installed between the sides of the two L-shaped seats (8), a pull-out frame (14) is extended from the front end of the sliding sleeve (13), the end of the pull-out frame (14) is fixedly installed with three upper clamping rings (25) in a T-shaped distribution, a lower frame (22) is slidably arranged below the pull-out frame (14), the lower frame (22) is slidably connected to the fixed frame (5), and the end of the lower frame (22) is fixedly installed with three lower clamping rings (16) in a T-shaped distribution; A carrier (31) is fixedly installed at the rear of the upper end of the storage table (2), and two No. 2 slot columns (32) are symmetrically fixedly installed at the upper end of the carrier (31). The upper push seat (35) and the lower push seat (11) are slidably installed on the surface of the No. 2 slot column (32), and a spring body (36) is wound around the outer side of the No. 2 slot column (32), one end of the spring body (36) is fixed to the lower end of the upper push seat (35), and the other end of the spring body (36) is fixed to the upper end of the lower push seat (11); A servo push cylinder (29) is fixedly installed at the lower end of the storage table (2), and a pull rod (30) is fixedly installed at the output end of the servo push cylinder (29). The pull rod (30) passes through the storage table (2), the carrier (31), and the lower push seat (11) in sequence. The pull rod (30) is slidably connected with the storage table (2), the carrier (31), and the lower push seat (11). The upper push seat (35) is embedded in the end of the pull rod (30). An arc-shaped positioning edge (37) extends from the upper corner of the storage table (2), and the opposite surfaces of the L-shaped seat (8) and the pressure plate (9) are provided with anti-slip grooves (17); The bag holding member comprises a plate shaft (6) rotatably mounted on the end of a fixing frame (5); the outer surface of the plate shaft (6) is inlaid with a bag holding plate (3); the bag holding plate (3) is inclined downward, and two limiting edges (4) extend symmetrically from the upper end of the bag holding plate (3); A gear (28) is coaxially embedded at the rear end of the plate shaft (6), a toothed plate (38) is meshed on the side of the gear (28), the toothed plate (38) is elastically connected to the fixing frame (5), a push claw (12) is arranged above the toothed plate (38), and an end of the push claw (12) is fixed to the other side of the upper push seat (35); A bag body (39) is placed on the bag supporting plate (3), the bottom of the bag body (39) is located at the L-shaped seat (8), the discharge pipe (40) of the bag body (39) is located in the U-shaped seat (18), and the pipe plug (41) of the bag body (39) is located in the lower clamp ring (16).

2. A multiplex PCR quantitative detector according to claim 1, characterized in that: An extension frame (7) is fixedly installed between the lower ends of the two L-shaped seats (8), and the end of the extension frame (7) is fixed to the fixed frame (5). A plate frame (10) is fixedly installed on the upper end of the pressure plate (9), and the end of the plate frame (10) is fixed to the lower push seat (11). A square frame (33) is slidably installed inside the sliding sleeve (13), and the square frame (33) passes through both sides of the sliding sleeve (13), and the end of the square frame (33) is fixed to the lower push seat (11).

3. A multiplex PCR quantitative detector according to claim 1, characterized in that: A synchronous column (15) is fixedly mounted on the rear end of the lower frame (22); the pull-out frame (14) is slidably mounted on the outer surface of the synchronous column (15); a guide frame (21) is fixedly mounted on the lower end of the lower frame (22); a guide sleeve (20) is slidably mounted on the outer surface of the guide frame (21); and an end of the guide sleeve (20) is fixed to the fixed frame (5).

4. A multiplex PCR quantitative detector according to claim 1, characterized in that: A No. 1 slot column (23) is fixedly installed in the middle of the tooth plate (38), a column frame (26) is slidably installed on the outer surface of the No. 1 slot column (23), the end of the column frame (26) is fixed to the fixed frame (5), a return spring (27) is wound around the outer side of the No. 1 slot column (23), the upper end of the return spring (27) is fixed to the tooth plate (38), the lower end of the return spring (27) is fixed to the upper end of the column frame (26), and a column cap (24) is coaxially inlaid at the lower end of the No. 1 slot column (23), and the column cap (24) is fitted to the lower end of the column frame (26).

Images