Modular high performance liquid chromatography column homogenizer jar

Abstract

The utility model discloses modularization high -efficient liquid chromatography column homogenate jar, including assembly jar and connecting ring, the assembly jar is multiple, and the bottom of assembly jar all is provided with connecting ring, and the volume of assembly jar is 10ML, connecting ring is connected with assembly jar thread, and a group of assembly jar can be connected with another group of assembly jar up and down arrangement through connecting ring, the top of assembly jar is provided with the shunt head, and the shunt head is connected with assembly jar thread, the bottom of connecting ring is provided with liquid outlet portion, and liquid outlet portion is connected with connecting ring thread, the bottom of liquid outlet portion is provided with liquid outlet pipe, the inside of liquid outlet pipe is provided with the plugging screw, and the plugging screw is connected with liquid outlet pipe thread. The utility model not only realized modularization assembly use, facilitated the adaptation different volume's chromatographic column and dismouting independent cleaning, avoided the filler residual in the dead angle, reduced the cost expenditure, and improved the flexibility of use.

Description

Technical Field

[0001] This utility model relates to the field of homogenizer technology, specifically a modular high-performance liquid chromatography column homogenizer. Background Technology

[0002] Traditional homogenizers are single-chamber containers with fixed volumes. Different sized chromatographic columns require specific containers, and laboratories need to purchase multiple sizes of containers, which is costly and inflexible. Small-volume containers cannot be adapted to large-sized preparative columns, while filling small columns into large-volume containers can easily lead to waste of packing material and homogenate, as well as wasted filling time. To improve this situation, a modular high-performance liquid chromatography column homogenizer is proposed.

[0003] As disclosed in CN219647299U, a high-pressure homogenizer for packing a liquid chromatography column includes a tank body. One end of the tank body is provided with a first outlet, and a switch valve is installed at the first outlet. The other end of the tank body is connected to an inlet pipe. A rotatable collar is fitted on the outside of the inlet pipe. A sleeve is fitted on the lower outer side of the tank body. The tank body and the sleeve can rotate relative to each other. The outer side of the tank body is provided with a spiral groove. The tank body also includes a cover. One end of the cover is open. The inner diameter of the cover opening is the same as the diameter of the tank body. The cover is inserted into the outside of the tank body from the top through the opening at one end. A spring is connected between the top of the collar and the inner side of the top of the cover. A feed pipe is coaxially connected inside the inlet pipe. One end of the feed pipe extends to the outside of the inlet pipe and is provided with a feed port. A foldable end cap is connected to the feed port. The other end of the feed pipe passes through a stirring component and communicates with the inside of the tank body.

[0004] Although this high-pressure homogenizer for packing liquid chromatography columns is equipped with a cover, when the cover moves downwards, it can drive the stirring head of the stirring component to squeeze the packing material and homogenate. At the same time, when the cover moves downwards, the ball bearings slide in the spiral groove, which can drive the tank to rotate. Then, the protrusions on the outside of the stirring head can uniformly stir the homogenate and packing material. This high-pressure homogenizer for packing liquid chromatography columns is equipped with a stirring component. The displacement liquid entering through the inlet pipe is discharged from the second outlet, enters the groove through the through hole, and finally enters the tank through the drain port. Since the drain port is set circumferentially along the inner wall of the groove, the displacement liquid squeezed in by pressure does not directly collide with the homogenate. Instead, it first passes through the top plate and enters the groove, and then is sprayed from the drain port onto the inner wall of the tank and flows down into the tank. This makes the homogenate in the tank stable and less prone to impact, thus improving the uniformity of the column bed.

[0005] However, this does not solve the problem that existing homogenizers are not conducive to modular assembly and use, are not suitable for chromatographic columns of different volumes, and are difficult to disassemble and clean independently, thus affecting the flexibility of use. Utility Model Content

[0006] The purpose of this invention is to provide a modular high-performance liquid chromatography column homogenizer to solve the problems mentioned in the background art, such as the inconvenience of modular assembly and use of homogenizers, the difficulty in adapting to chromatographic columns of different volumes and the inability to disassemble and clean them independently, which affects the flexibility of use.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a modular high-performance liquid chromatography column homogenizer, comprising an assembly tank and a connecting ring. Multiple assembly tanks are provided, and each assembly tank has a connecting ring at its bottom. The volume of each assembly tank is 10 ml. The connecting ring is threadedly connected to the assembly tank, and one set of assembly tanks can be connected vertically to another set of assembly tanks via the connecting ring. A flow divider is provided at the top of each assembly tank and is threadedly connected to the assembly tank. A liquid outlet is provided at the bottom of the connecting ring and is threadedly connected to the connecting ring. A liquid outlet pipe is provided at the bottom of the liquid outlet pipe, and a sealing screw is provided inside the liquid outlet pipe and is threadedly connected to the liquid outlet pipe.

[0008] Preferably, a diversion valve is provided at the top of the diversion head, a handle is provided on the outside of the diversion head, and a clamping frame is provided on the side wall of the handle. A rack is slidably provided inside the clamping frame, and an adjusting claw is provided at one end of the rack. The two ends of the adjusting claw are respectively connected to the rack and the clamping frame.

[0009] Preferably, a transmission gear is movably installed inside the clamping frame on one side of the rack, and the transmission gear meshes with the rack. A driven gear is movably installed inside the clamping frame on one side of the transmission gear, and the driven gear meshes with the transmission gear.

[0010] Preferably, a fixed gripper is installed on the side wall of the clamping frame, and an adjusting gripper is installed on the side wall of the driven gear, and the adjusting gripper is slidably connected to the clamping frame.

[0011] Preferably, the outer wall of the diversion valve is provided with a connecting pipe and a liquid injection pipe, and the side wall of the diversion valve is provided with a limit ring, the surface of which is provided with multiple sets of limit pin holes at equal intervals.

[0012] Preferably, a valve body is movably installed inside the diversion valve, and the valve body is provided with a first channel and a second channel, wherein the first channel is connected to the injection pipe and the second channel is connected to the connecting pipe.

[0013] Preferably, a hinge shaft is installed at the center of the valve body, and the hinge shaft extends to the outside of the diverter valve, and an adjusting arm is fitted on the surface of the hinge shaft outside the diverter valve.

[0014] Preferably, a limit frame is provided on the side wall of the adjusting arm, a limit post is slidably provided inside the limit frame, a spring is provided on the surface of the limit post, and the two ends of the spring are respectively connected to the limit post and the limit frame, and the limit post can be inserted into the interior of the limit pin hole.

[0015] Compared with the prior art, the beneficial effects of this utility model are: the homogenizer not only realizes modular assembly and use, which facilitates the adaptation to chromatographic columns of different volumes and independent disassembly and cleaning, avoids packing material residue in dead corners, reduces cost expenditure, but also improves the flexibility of use.

[0016] (1) Calculate the required volume according to the column size, take the corresponding number of assembly tanks according to the volume, connect multiple assembly tanks with connecting rings to form the homogenizing tank required for the corresponding volume, and then pour the corresponding packing and homogenizing liquid into the tank according to the operation procedure. After the homogenizing liquid and packing are ultrasonically dispersed, the sealing screw is removed, the outlet pipe is connected to the column, the pneumatic pump is connected, and the displacement liquid is pressed into the tank through the split head to inject the homogenizing liquid into the column. After the injection is completed, the multiple assembly tanks are disassembled, and the inside and outside of the assembly tanks can be rinsed to avoid residual liquid in dead corners. This realizes modular assembly and use, which is convenient for adapting to different volumes of columns and independent cleaning, avoids packing residue in dead corners, reduces cost expenditure, and improves the flexibility of use.

[0017] (2) Hold the handle and press the rack. The rack will cause the second spring to contract, and the rack will drive the driven gear to rotate through the transmission gear. The transmission gear and the driven gear rotate in opposite directions to move the adjusting jaw away from the fixed jaw. Place the fixed jaw and the adjusting jaw on both sides of the tank. Release the rack. Under the elastic cooperation of the second spring, the second spring will drive the rack to reset. The rack will drive the transmission gear and the driven gear to rotate in opposite directions to move the adjusting jaw closer to the tank. With the cooperation of the fixed jaw, the adjusting jaw and the fixed jaw will clamp and fix the tank. Then, hold the handle to move the tank. Place the packing inside the tank. Connect the distributor head to the top assembly tank. Connect the connecting pipe to the air pump. Connect the injection pipe to the slurry source. Before adding the slurry, the air inside the tank needs to be extracted. The air pump extracts air into the tank through the connecting pipe, the second channel and the distributor head. After the air is discharged, pull the limiting column. Under the limiting cooperation of the limiting frame, the limiting column will drive the adjusting jaw closer to the tank. The spring contracts to pull the limiting column out of the limiting pin hole. Rotating the adjusting arm rotates the hinge shaft, which in turn rotates the valve body, sealing the connecting pipe. Then, the spring is released, and with its elasticity, the limiting column resets and inserts into the corresponding limiting pin hole, maintaining the valve body in its current state. This rotates the first channel to the connection position between the injection tube and the splitter head, creating an open channel. The homogenate source is injected into the tank through the injection tube, first channel, and splitter head. After injection, the homogenate is ultrasonically dissolved and dispersed with the packing material. The outlet tube is then connected to the chromatographic column. The adjusting arm is rotated in the opposite direction to block the injection tube and open the connecting pipe. At this point, the gas pump switches from suction mode to delivery mode, injecting replacement fluid into the connecting pipe while simultaneously injecting gas. The gas moves the replacement fluid, which then presses the mixed packing material into the chromatographic column, thus completing the packing process. Attached Figure Description

[0018] Figure 1 This is a three-dimensional exploded structure diagram of the present invention;

[0019] Figure 2 This is a three-dimensional structural diagram of the present invention;

[0020] Figure 3 This is a three-dimensional exploded structure diagram of the present invention;

[0021] Figure 4 This is a three-dimensional structural diagram of the diversion valve of this utility model;

[0022] Figure 5 This is a front view cross-sectional structural diagram of the diversion valve of this utility model;

[0023] Figure 6This is a top view cross-sectional structural diagram of the clamping frame of this utility model.

[0024] In the diagram: 1. Assembly tank; 2. Diverter valve; 3. Fixed gripper; 4. Handle; 5. Rack; 6. Connecting ring; 7. Transmission gear; 8. Discharge section; 9. Sealing screw; 10. Diverter head; 11. Adjusting gripper; 12. Connecting pipe; 13. Injection pipe; 14. Clamping frame; 15. Discharge pipe; 16. Limiting ring; 17. Hinge shaft; 18. Adjusting arm; 19. Limiting pin hole; 20. Limiting post; 21. Limiting frame; 22. Spring; 23. Valve body; 24. Driven gear; 25. First channel; 26. Second channel; 27. Second spring. Detailed Implementation

[0025] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0026] Please see Figure 1-6 The present invention provides an embodiment of a modular high-performance liquid chromatography column homogenizer, comprising an assembly tank 1 and a connecting ring 6. The assembly tank 1 is in multiple sets, and each assembly tank 1 is provided with a connecting ring 6 at its bottom end. The volume of the assembly tank 1 is 10 ml. The connecting ring 6 is threadedly connected to the assembly tank 1. One set of assembly tank 1 can be connected to another set of assembly tank 1 vertically through the connecting ring 6. The top of the assembly tank 1 is provided with a split head 10, and the split head 10 is threadedly connected to the assembly tank 1. The bottom end of the connecting ring 6 is provided with a liquid outlet 8, and the liquid outlet 8 is threadedly connected to the connecting ring 6. The bottom end of the liquid outlet 8 is provided with a liquid outlet pipe 15. The inside of the liquid outlet pipe 15 is provided with a sealing screw 9, and the sealing screw 9 is threadedly connected to the liquid outlet pipe 15.

[0027] Calculate the required volume based on the column size, take the corresponding number of assembly tanks 1 according to the volume, and connect multiple sets of assembly tanks 1 through connecting rings 6 to form the homogenizing tank body required for the corresponding volume. Then, according to the operation procedure, pour the corresponding packing material and homogenate into the tank body. After the homogenate and packing material are ultrasonically dispersed, remove the sealing screws 9, connect the liquid outlet pipe 15 to the column, connect the pneumatic pump, and press the displacement liquid into the tank body through the splitter head 10 to inject the homogenate into the column. After the injection is completed, disassemble multiple sets of assembly tanks 1, and then rinse the inside and outside of the assembly tanks 1 to avoid residual liquid remaining in dead corners. This realizes modular assembly and use, which is convenient for adapting to columns of different volumes and independent cleaning, avoids packing material residue in dead corners, reduces cost expenditure, and improves the flexibility of use.

[0028] A diversion valve 2 is provided at the top of the diversion head 10, a handle 4 is provided on the outside of the diversion head 10, and a clamping frame 14 is provided on the side wall of the handle 4. A rack 5 is slidably provided inside the clamping frame 14. An adjusting claw 11 is provided at one end of the rack 5, and the two ends of the adjusting claw 11 are respectively connected to the rack 5 and the clamping frame 14.

[0029] A transmission gear 7 is movably installed inside the clamping frame 14 on one side of the rack 5, and the transmission gear 7 meshes with the rack 5. A driven gear 24 is movably installed inside the clamping frame 14 on one side of the transmission gear 7, and the driven gear 24 meshes with the transmission gear 7.

[0030] A fixed gripper 3 is installed on the side wall of the clamping frame 14, and an adjusting gripper 11 is installed on the side wall of the driven gear 24, and the adjusting gripper 11 is slidably connected to the clamping frame 14.

[0031] The outer wall of the diversion valve 2 is provided with a connecting pipe 12 and a liquid injection pipe 13 respectively. The side wall of the diversion valve 2 is provided with a limit ring 16. The surface of the limit ring 16 is provided with multiple sets of limit pin holes 19 at equal intervals.

[0032] The diversion valve 2 has a valve body 23 movably installed inside. The valve body 23 has a first channel 25 and a second channel 26 respectively. The first channel 25 is connected to the injection pipe 13, and the second channel 26 is connected to the connecting pipe 12.

[0033] A hinge shaft 17 is installed at the center of the valve body 23, and the hinge shaft 17 extends to the outside of the diversion valve 2, and an adjusting arm 18 is fitted on the surface of the hinge shaft 17 outside the diversion valve 2.

[0034] A limit frame 21 is provided on the side wall of the adjusting arm 18. A limit post 20 is slidably provided inside the limit frame 21. A first spring 22 is provided on the surface of the limit post 20. The two ends of the first spring 22 are respectively connected to the limit post 20 and the limit frame 21. The limit post 20 can be inserted into the inside of the limit pin hole 19.

[0035] After the multiple sets of assembly tanks 1 are assembled, to avoid temperature changes in the tank due to handling and thus affecting the performance of the packing, hold the handle 4 and press the rack 5. The rack 5 will drive the second spring 27 to contract. Under the mutual meshing of the rack 5 and the transmission gear 7, and the mutual meshing of the driven gear 24 and the transmission gear 7, the rack 5 drives the driven gear 24 to rotate through the transmission gear 7. The transmission gear 7 and the driven gear 24 rotate in opposite directions, so that the adjusting jaw 11 moves away from the fixed jaw 3. Place the fixed jaw 3 and the adjusting jaw 11 on both sides of the tank body, release the rack 5, and under the elastic cooperation of the adjusting jaw 11, the adjusting jaw 11 will move away from the fixed jaw 3. The clamp 11 drives the rack 5 to reset, and the rack 5 drives the transmission gear 7 and the driven gear 24 to rotate in opposite directions, so that the adjusting clamp 11 moves closer to the tank body. With the cooperation of the fixed clamp 3, the adjusting clamp 11 and the fixed clamp 3 clamp and fix the tank body. Then, by holding the handle 4, the tank body can be moved to place the packing material into the tank body. Connect the distributor head 10 to the top assembly tank 1, connect the connecting pipe 12 to the air pump, and connect the injection pipe 13 to the homogenizing liquid source. Before adding the homogenizing liquid, the air in the tank body needs to be extracted. Turn on the air pump, and the air pump will extract air into the tank body through the connecting pipe 12, the second channel 26 and the distributor head 10. After the body is discharged, pull out the limiting post 20. Under the limiting action of the limiting frame 21, the limiting post 20 drives the first spring 22 to retract, thus pulling the limiting post 20 out of the limiting pin hole 19. Rotate the adjusting arm 18, which drives the hinge shaft 17 to rotate. The hinge shaft 17 then drives the valve body 23 to rotate, thus blocking the connecting pipe 12. After that, release the first spring 22. Under the elastic action of the first spring 22, the limiting post 20 returns to its original position and inserts into the corresponding limiting pin hole 19, keeping the valve body 23 in its current state. This rotates the first channel 25 to the connection position between the injection pipe 13 and the diverter head 10. Position the injection tube 13, the first channel 25, and the splitter head 10 to form an open channel. Inject the homogenate source into the tank through the injection tube 13, the first channel 25, and the splitter head 10. After the homogenate is injected, it is ultrasonically fused and dispersed with the packing material. Then, connect the outlet tube 15 to the chromatographic column. Rotate the adjusting arm 18 in the opposite direction again to block the channel of the injection tube 13 and open the channel of the connecting tube 12. At this time, the gas pump changes from the gas extraction mode to the gas delivery mode. While injecting gas, the replacement liquid is injected into the connecting tube 12. The gas drives the replacement liquid to move, and the replacement liquid presses the mixed packing material into the chromatographic column, thereby completing the packing work of the chromatographic column.

[0036] Working principle: First, calculate the required volume based on the column size. Take the corresponding number of assembly tanks 1 according to the volume, and connect multiple sets of assembly tanks 1 using connecting rings 6 to form the homogenizing tank body required for the corresponding volume. Then, according to the operating procedure, pour the corresponding packing material and homogenate into the tank body. After ultrasonically dispersing the homogenate and packing material, remove the sealing screws 9, connect the outlet pipe 15 to the column, and connect the pneumatic pump to force the displacement liquid into the tank body through the splitter head 10, thus injecting the homogenate into the column. After injection, disassemble the multiple sets of assembly tanks 1 to rinse the inside and outside of the assembly tanks 1 to prevent residual liquid from remaining in dead corners. After multiple sets of assembly tanks 1 are assembled, to avoid temperature changes caused by handling the tank body, [further steps are needed]. This affects the performance of the packing. Holding the handle 4, press the rack 5. The rack 5 drives the second spring 27 to contract. Under the mutual meshing of the rack 5 and the transmission gear 7, the rack 5 drives the driven gear 24 to rotate through the transmission gear 7. The transmission gear 7 and the driven gear 24 rotate in opposite directions, so that the adjusting jaw 11 moves away from the fixed jaw 3. Place the fixed jaw 3 and the adjusting jaw 11 on both sides of the tank. Release the rack 5. Under the elastic cooperation of the second spring 27, the second spring 27 drives the rack 5 to return to its original position. The rack 5 drives the transmission gear 7 and the driven gear 24 to rotate in opposite directions, so that the adjusting jaw 11 moves closer to the tank. With the cooperation of the fixed jaw 3, the adjusting jaw 11 and the fixed jaw 3 clamp and fix the tank. Then, holding the handle... 4. This will move the tank body, place the packing material inside the tank, connect the distributor head 10 to the top assembly tank 1, connect the connecting pipe 12 to the air pump, and connect the injection pipe 13 to the slurry source. Before adding the slurry, the air inside the tank needs to be extracted. The air pump extracts air into the tank through the connecting pipe 12, the second channel 26, and the distributor head 10. After the air is discharged, pull out the limiting post 20. Under the limiting action of the limiting frame 21, the limiting post 20 drives the first spring 22 to retract, thereby pulling the limiting post 20 out of the limiting pin hole 19. Rotate the adjusting arm 18, which drives the hinge shaft 17 to rotate. The hinge shaft 17 drives the valve body 23 to rotate, and the valve body 23 blocks the connecting pipe 12. Then, release the first spring 22. Under the elastic action of spring 22, the first spring 22 drives the limiting post 20 to reset and insert into the corresponding limiting pin hole 19, keeping the valve body 23 in its current state. This rotates the first channel 25 to the connection position between the injection tube 13 and the splitter head 10, forming an open channel between the injection tube 13, the first channel 25, and the splitter head 10. The homogenate source is injected into the tank through the injection tube 13, the first channel 25, and the splitter head 10. After the homogenate is injected, it is ultrasonically dissolved and dispersed with the packing material. The outlet tube 15 is then connected to the chromatographic column. The adjusting arm 18 is rotated in the opposite direction again to block the channel of the injection tube 13 and open the channel of the connecting tube 12. At this time, the gas pump changes from the suction mode to the delivery mode, injecting replacement fluid into the connecting tube 12 while injecting gas.The gas drives the replacement fluid, which in turn forces the mixed packing material into the chromatographic column, thus completing the packing process.

[0037] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any indirect modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A modular high-performance liquid chromatography column homogenizer, comprising an assembly tank (1) and a connecting ring (6), characterized in that: The assembly tank (1) consists of multiple sets, and each assembly tank (1) is provided with a connecting ring (6) at its bottom end. The volume of the assembly tank (1) is 10ML. The connecting ring (6) is threadedly connected to the assembly tank (1). One set of assembly tanks (1) can be connected to another set of assembly tanks (1) vertically through the connecting ring (6). The top of the assembly tank (1) is provided with a diverter head (10), and the diverter head (10) is threadedly connected to the assembly tank (1). The bottom end of the connecting ring (6) is provided with a liquid outlet (8), and the liquid outlet (8) is threadedly connected to the connecting ring (6). The bottom end of the liquid outlet (8) is provided with a liquid outlet pipe (15), and the inside of the liquid outlet pipe (15) is provided with a sealing screw (9), and the sealing screw (9) is threadedly connected to the liquid outlet pipe (15).

2. The modular high-performance liquid chromatography column homogenizer according to claim 1, characterized in that: The top of the diverter (10) is provided with a diverter valve (2), the outside of the diverter (10) is provided with a handle (4), and a clamping frame (14) is provided on the side wall of the handle (4). A rack (5) is slidably provided inside the clamping frame (14). A second spring (27) is provided at one end of the rack (5), and the two ends of the second spring (27) are respectively connected to the rack (5) and the clamping frame (14).

3. The modular high-performance liquid chromatography column homogenizer according to claim 2, characterized in that: A transmission gear (7) is movably installed inside the clamping frame (14) on one side of the rack (5), and the transmission gear (7) meshes with the rack (5). A driven gear (24) is movably installed inside the clamping frame (14) on one side of the transmission gear (7), and the driven gear (24) meshes with the transmission gear (7).

4. The modular high-performance liquid chromatography column homogenizer according to claim 2, characterized in that: The clamping frame (14) has a fixed clamping claw (3) installed on its side wall, and the driven gear (24) has an adjusting clamping claw (11) installed on its side wall, and the adjusting clamping claw (11) is slidably connected to the clamping frame (14).

5. The modular high-performance liquid chromatography column homogenizer according to claim 2, characterized in that: The outer wall of the diversion valve (2) is provided with a connecting pipe (12) and an injection pipe (13). The side wall of the diversion valve (2) is provided with a limit ring (16). The surface of the limit ring (16) is provided with multiple sets of limit pin holes (19) at equal intervals.

6. The modular high-performance liquid chromatography column homogenizer according to claim 2, characterized in that: The diverter valve (2) has a valve body (23) installed inside. The valve body (23) has a first channel (25) and a second channel (26) inside. The first channel (25) is connected to the injection pipe (13), and the second channel (26) is connected to the connecting pipe (12).

7. The modular high-performance liquid chromatography column homogenizer according to claim 6, characterized in that: A hinge shaft (17) is installed at the center of the valve body (23), and the hinge shaft (17) extends to the outside of the diversion valve (2), and an adjusting arm (18) is fitted on the surface of the hinge shaft (17) outside the diversion valve (2).

8. The modular high-performance liquid chromatography column homogenizer according to claim 7, characterized in that: A limit frame (21) is provided on the side wall of the adjusting arm (18). A limit post (20) is slidably provided inside the limit frame (21). A first spring (22) is provided on the surface of the limit post (20). The two ends of the first spring (22) are connected to the limit post (20) and the limit frame (21) respectively. The limit post (20) can be inserted into the inside of the limit pin hole (19).

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