Limiting structure and cantilever type wire feeder
By designing the restriction structure and control components for the cantilever wire feeder, the problem of the impact risk of the smoke hood in the non-working state and the untimely stopping of smoking work is solved, and a safe and reliable operating environment and automated control effect are achieved.
Patent Information
- Application Number
- CN202422109024.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-29
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-08-29
AI Technical Summary
In the non-working state, the smoke hood of the welding smoke dust removal and suction equipment is prone to impact staff or others. When multiple groups of cantilever wire feeders are running together, the smoking work will not stop in time after the single cantilever wire feeder stops working, and it is easy to forget to close.
A restriction structure is designed, including mounting shaft, cantilever, rotating block and telescopic tube. Through the coordination of the rotating restriction and telescopic restriction, the telescopic tube is retracted in a non-working state, the smoke hood is in a safe area, and the timely stop of smoking work is achieved through the control component.
It effectively avoids the risk of the smoke hood hitting staff or others in a non-working state, and solves the problem of smoking work not being stopped in time after a single cantilever wire feeder stops working, reducing the possibility of artificial forgetting to close.
Smart Images
Figure CN223028660U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of cantilever wire feeders, in particular to a limiting structure and a cantilever wire feeder. Background Art
[0002] The cantilever wire feeder is generally fixed on a fixed column and is in a hanging mode. The control module sends the welding wire to the position of the welding torch through the wire feeding nozzle module and is used in cooperation with the welding fume dust removal and suction device.
[0003] The cantilever wire feeder has a working state and a non-working state. In the non-working state, the staff generally rotates the cantilever away from the working area. During the process of moving from the working area to the non-working area or in the non-working area, the fume hood hanging down from the welding fume dust removal and suction device may hit the staff or others, which is likely to cause damage to the staff and equipment in this situation.
[0004] At the same time, when multiple groups of cantilever wire feeders operate together and use the same smoking main pipe, there will be a problem that the smoking work will not stop in time when a single cantilever wire feeder stops working, or it is necessary to manually close the single-control smoking structure, and it is easy for the staff to forget to close it after stopping the work of the cantilever wire feeder. Summary of the Utility Model
[0005] In view of the problem that in the process of the above-mentioned or existing cantilever wire feeder moving from the working area to the non-working area or in the non-working area, the fume hood hanging down from the welding fume dust removal and suction device may hit the staff or others, which is likely to cause damage to the staff and equipment in this situation, the present utility model is proposed.
[0006] Therefore, the purpose of the present utility model is to propose a limiting structure.
[0007] To solve the above technical problems, the present utility model proposes the following technical solution: a limiting structure, including a main body assembly composed of a mounting shaft, a cantilever, a rotating block and a telescopic tube, and an adjusting assembly composed of a rotation limiting member, a telescopic limiting member and a limiting hole. The cantilever is fixedly connected to the rotating block, the rotating block is arranged on the mounting shaft, the telescopic tube is arranged on the cantilever and is movably connected to the rotating block. The rotation limiting member is arranged in the rotating block, the telescopic limiting member is arranged in the rotating block, and the limiting hole is opened on the mounting shaft and is matched with the rotation limiting member and the telescopic limiting member.
[0008] As a preferred scheme of the limiting structure of the present utility model, wherein: the rotation limiting member includes a braking trigger member and a rotation braking member. The braking trigger member is arranged at one end of the telescopic tube extending into the rotating block, and the rotation braking member is arranged in the rotating block and is matched with the braking trigger member.
[0009] As a preferred embodiment of the limiting structure of the present utility model, the rotation braking member includes a pushing block, a braking rod, and a first spring. The pushing block is disposed within the rotating block. The braking rod is fixedly connected to the pushing block. The first spring is fixedly connected to the inner wall of the rotating block and the pushing block. The braking rod cooperates with the limiting hole.
[0010] As a preferred embodiment of the limiting structure of the present utility model, a pushing groove is formed on the pushing block, and the pushing groove cooperates with the inclined surface on the braking trigger member.
[0011] As a preferred embodiment of the limiting structure of the present utility model, the telescopic limiting member includes a telescopic braking member and a blocking member. The telescopic braking member is disposed within the rotating block and cooperates with the braking trigger member. The blocking member is disposed within the rotating block and cooperates with the limiting hole and the telescopic braking member.
[0012] As a preferred embodiment of the limiting structure of the present utility model, the telescopic braking member includes a limiting rod and a moving block. The limiting rod is fixedly connected to the moving block. One end of the limiting rod away from the moving block is a braking end, and the braking end cooperates with the spherical groove formed on the braking trigger member.
[0013] As a preferred embodiment of the limiting structure of the present utility model, the blocking member includes a second spring, a pressing block, and a spherical end. The second spring is fixedly connected within the rotating block and fixedly connected to the pressing block. The spherical end is disposed at one end of the pressing block away from the second spring.
[0014] As a preferred embodiment of the limiting structure of the present utility model, an activity groove is formed on the pressing block, and the shape of the activity groove corresponds to the shape of one end of the moving block away from the limiting rod.
[0015] The beneficial effect of the present utility model is as follows: Through the cooperation of the main body assembly and the adjustment assembly, in the non-working state of the cantilever wire feeder, the telescopic tube is ensured to be in a contracted state, so that the fume hood is always in a safe area in the non-working state, avoiding blocking the movement route of the staff and avoiding hitting the staff and bystanders.
[0016] In view of the problem that in the case of multiple cantilever wire feeders operating together and using the same smoking main pipe in the above-mentioned or existing cantilever wire feeders, when a single cantilever wire feeder stops working, the smoking work will not stop in time, or it is necessary to manually close the single-control smoking structure, and it is easy for the staff to forget to close it after stopping the work of the cantilever wire feeder, the present utility model is proposed.
[0017] To solve the above technical problems, the present utility model further provides the following technical solution: A cantilever wire feeder, comprising a control assembly composed of a support member, a trigger member, and a sealing member. The support member is disposed in a smoking pipe fixedly connected and communicating with the telescopic pipe. The trigger member is disposed within the support member, and the sealing member is disposed in the smoking pipe.
[0018] As a preferred embodiment of the cantilever wire feeder of the present utility model, wherein: The support member includes a support rod and a support cylinder. The support rod fixedly connects the inner wall of the smoking pipe and the support cylinder. The trigger member includes a trigger block and an elastic member. The trigger block includes a trigger end and a sealing end. The trigger end is disposed at one end of the trigger block extending into the telescopic pipe and cooperates with the telescopic pipe. The sealing end is disposed at the end away from the trigger end and extends out of the support cylinder. The elastic member is disposed within the trigger block and fixedly connected to the support cylinder. The sealing member includes a flue block disposed on the inner wall of the smoking pipe and a sealing ring disposed on the flue block. The flue block corresponds to the shape of the sealing end and is symmetrically disposed to form a valve port. The sealing ring cooperates with the sealing end.
[0019] The beneficial effects of the present utility model are as follows: Through the action of the main body assembly and the control assembly, the working cantilever stops the smoking work in a timely manner after stopping work, avoiding the problem that the smoking work of a single cantilever cannot be stopped when the continuous exhaust pipe is operating collectively or the problem of manually closing a single smoking structure, and avoiding the problem that the staff forgets to stop the smoking structure after stopping work. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. Among them:
[0021] Figure 1 Schematic diagram of the limiting structure and the overall device of the cantilever wire feeder.
[0022] Figure 2 Schematic diagram of the rotation locking state of the adjustment component structure.
[0023] Figure 3 Schematic diagram of the telescopic locking state of the adjustment component structure.
[0024] Figure 4 Schematic diagram of the position of the control component.
[0025] Figure 5 Schematic cross-sectional view of the control component structure. Detailed implementation manners
[0026] To make the above objects, features, and advantages of the present utility model more obvious and understandable, the following will describe the detailed implementation manners of the present utility model in conjunction with the accompanying drawings of the specification.
[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present utility model. However, the present utility model can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed below.
[0028] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation manner of the present utility model. The "in one embodiment" appearing in different places in this specification does not all refer to the same embodiment, nor is it a separate or alternative embodiment that excludes other embodiments.
[0029] Embodiment 1
[0030] Referring to Figures 1 to 3 , which is the first embodiment of the present utility model. This embodiment provides a limiting structure. The limiting structure includes a main body assembly 100 composed of a mounting shaft 101, a cantilever 102, a rotating block 103, and a telescopic tube 104, and an adjusting assembly 200 composed of a rotation limiting member 201, a telescopic limiting member 202, and a limiting hole 203.
[0031] Specifically, the cantilever 102 is fixedly connected to the rotating block 103. The rotating block 103 is arranged on the mounting shaft 101. The telescopic tube 104 is arranged on the cantilever 102 and is movably connected to the rotating block 103. The rotation limiting member 201 is arranged inside the rotating block 103. The limiting hole 203 is opened on the mounting shaft 101. The rotation limiting member 201 includes a braking trigger member 201a and a rotation braking member 201b. The braking trigger member 201a is arranged at one end of the telescopic tube 104 extending into the rotating block 103. The rotation braking member 201b is arranged inside the rotating block 103 and cooperates with the braking trigger member 201a. The rotation braking member 201b includes a pushing block 201b-1, a braking rod 201b-2, and a first spring 201b-3. The pushing block 201b-1 is arranged inside the rotating block 103. The braking rod 201b-2 is fixedly connected to the pushing block 201b-1. The first spring 201b-3 is fixedly connected to the inner wall of the rotating block 103 and the pushing block 201b-1. The braking rod 201b-2 cooperates with the limiting hole 203. A pushing groove 201b-1a is opened on the pushing block 201b-1. The pushing groove 201b-1a cooperates with the inclined surface 201a-1 on the braking trigger member 201a.
[0032] During use, when the cantilever 102 is in the working state, the brake lever 201b-2 is located within the limit hole 203, and the first spring 201b-3 is in its normal state without being stretched or compressed. At this time, since the brake lever 201b-2 is within the limit hole 203, the brake lever 201b-2 and the mounting shaft 101 where the limit hole 203 is located form mutual limitation, thereby preventing the rotating block 103 from rotating. When the cantilever 102 changes from the working state to the non-working state, the telescopic tube 104 contracts following the motor and, after the contraction is completed, still travels a short distance, driving the brake trigger 201a to move. As a result, the inclined surface 201a-1 on the brake trigger 201a contacts the propulsion groove 201b-1a on the propulsion block 201b-1, thereby changing the direction of the force, causing the first spring 201b-3 to contract, and causing the propulsion block 201b-1 to gradually disengage from the limit hole 203, releasing the limitation between the mounting shaft 101 and the rotating block 103, so that the cantilever 102 can rotate. Conversely, when the cantilever 102 changes from the non-working state to the working state, the telescopic tube 104 is moved to drive the brake trigger 201a to move, causing the inclined surface 201a-1 to disengage from the propulsion groove 201b-1a, thereby releasing the limitation on the propulsion block 201b-1. Furthermore, the first spring 201b-3 releases its elastic force, enabling the propulsion block 201b-1 to enter the limit hole 203 again, thus preventing the cantilever 102 from rotating in the working state.
[0033] In summary, by providing the rotation limiting member 201 within the rotating block 103, the cantilever 102 cannot rotate until the telescopic tube 104 is retracted to the safe area, avoiding the problem that the telescopic tube 104 fails to retract the fume hood to the safe area during the process of the cantilever 102 moving from the working area to the non-working area, resulting in collisions with staff and bystanders and causing damage to personnel and equipment.
[0034] Embodiment 2
[0035] Refer to Figures 1 to 3 , which is the second embodiment of the present invention. Different from the previous embodiment, this embodiment provides a limiting structure including a telescopic limiting member 202 composed of a telescopic braking member 202a and a blocking member 202b.
[0036] Specifically, the telescopic brake member 202a is disposed within the rotating block 103 and cooperates with the brake trigger member 201a. The blocking member 202b is disposed within the rotating block 103 and cooperates with the limiting hole 203 and the telescopic brake member 202a. The telescopic brake member 202a includes a limiting rod 202a-1 and a moving block 202a-2. The limiting rod 202a-1 is fixedly connected to the moving block 202a-2. One end of the limiting rod 202a-1 away from the moving block 202a-2 is a braking end 202a-1a. The braking end 202a-1a can enter the spherical groove 201a-2 formed on the brake trigger member 201a and can freely slide out of the spherical groove 201a-2 when subjected to force. The blocking member 202b includes a second spring 202b-1, a pressing block 202b-2, and a spherical end 202b-3. The second spring 202b-1 is fixedly connected within the rotating block 103 and is fixedly connected to the pressing block 202b-2. The second spring 202b-1 is in a contracted state when the telescopic tube 104 has not started to contract. The spherical end 202b-3 is disposed at one end of the pressing block 202b-2 away from the second spring 202b-1. The diameter of the spherical end 202b-3 is slightly smaller than the size of the limiting hole 203, such that the spherical end 202b-3 can enter the limiting hole 203 and the pressing block 202b-2 cannot enter the limiting hole 203. Also due to the spherical structure, the limiting hole 203 can push out the spherical end 202b-3 during rotation. An activity groove 202b-2a is formed on the pressing block 202b-2. The shape of the activity groove 202b-2a corresponds to the shape of the end of the moving block 202a-2 away from the limiting rod 202a-1. Then, the moving block 202a-2 can enter the activity groove 202b-2a.
[0037] During use, when the cantilever 102 transitions from the working state to the non-working state, as the triggering member 201a reaches its full position, the position of the spherical groove 201a-2 corresponds to the position of the braking end 202a-1a. The braking end 202a-1a can enter the position of the spherical groove 201a-2, thereby locking the position of the triggering member 201a. At the same time, the telescopic tube 104 can be fixed. At this time, the second spring 202b-1 fixedly connected to the extrusion block 202b-2 is no longer restricted by the moving block 202a-2. The second spring 202b-1 releases the extrusion force and pushes the extrusion block 202b-2 towards the mounting shaft 101. At this time, the moving block 202a-2 is blocked by the extrusion block 202b-2 and cannot move. And when the cantilever is in a stagnant state in the non-working area, the spherical end 202b-3 enters the limiting hole 203. Due to the extra distance traveled by the spherical end 202b-3, the inclined surface pushing structure of the moving block 202a-2 cannot contact the movable groove 202b-2a. Therefore, the moving block 202a-2 cannot move, causing the braking end 202a-1a to continuously stay in the spherical groove 201a-2, making the telescopic tube 104 unable to expand and contract. When the cantilever 102 is rotated and enters the working area, the spherical end 202b-3 is affected by the limiting hole 203 and is squeezed to compress the second spring 202b-1, enabling the moving block 202a-2 to enter the movable groove 202b-2a, allowing the moving block 202a-2 to move. Therefore, by pulling the triggering member 201a, the braking end 202a-1a of the moving block 202a-2 can be removed from the spherical groove 201a-2, and then the telescopic tube 104 can move freely.
[0038] In summary, through the combined action of the telescopic limiting member 202 and the main body assembly 100, the telescopic tube 104 of the cantilever wire feeder cannot expand and contract in the non-working state, and it must be rotated by the cantilever 102 before it can expand and contract. In the non-working state, the fume hood is stably positioned relatively close to the mounting shaft 101, increasing the path space for staff to pass under the cantilever and effectively avoiding damage to personnel and equipment caused by accidental collisions.
[0039] Embodiment 3
[0040] Referring to Figures 1 to 5 , this is the third embodiment of the present invention. The embodiment provides a cantilever wire feeder, which includes the limiting structure in Embodiments 1 and 2, and also includes a control assembly 300 composed of a support member 301, a triggering member 302, and a sealing member 303.
[0041] Specifically, the support member 301 is arranged in a smoking pipe 304 which is fixedly connected and communicated with the telescopic tube 104. The mechanisms of the smoking pipe 304 and the telescopic tube 104 are communicated to absorb and collect smoke in the working area. The trigger member 302 is arranged in the support member 301, and the sealing member 303 is arranged in the smoking pipe 304.
[0042] Furthermore, the support member 301 includes a support rod 301a and a support tube 301b. The support rod 301a is fixedly connected to the inner wall of the smoking tube 304 and the support tube 301b, and supports the trigger member 302 without affecting the movement of smoke. The trigger member 302 includes a trigger block 302a and an elastic member 302b. The trigger block 302a includes a trigger end 302a-1 and a sealing end 302a-2. The trigger end 302a-1 is arranged at one end of the trigger block 302a extending into the telescopic tube 104 and has a slope structure. The trigger end 302a-1 can obtain the thrust from the telescopic tube 104 and convert the thrust direction during the retraction of the telescopic tube 104, so that it can move toward the inside of the smoking tube 304. The sealing end 302a-2 is arranged away from the trigger end One end of 302a-1 extends out of the support tube 301b, which is used to contact the sealing member 303 and seal the flue. The elastic member 302b is arranged in the trigger block 302a and is fixedly connected to the support tube 301b, so as to reset the trigger block 302a after the telescopic tube 104 is extended, thereby releasing the blockage of the flue. The sealing member 303 includes a flue block 303a arranged on the inner wall of the smoking pipe 304 and a sealing ring 303b arranged on the flue block 303a. The flue block 303a corresponds to the shape of the sealing end 302a-2 and is symmetrically arranged to form a valve port 303a-1. The sealing ring 303b is squeezed and deformed by the sealing end 302a-2, so that the sealing end 302a-2 fits the flue block 303a more closely, thereby enhancing the smoke sealing effect.
[0043] During use, when the telescopic pipe 104 retracts during the process of stopping operation, when the telescopic pipe 104 is about to complete the contraction movement, it will first touch the trigger end 302a-1. Due to the inclined surface structure of the trigger end 302a-1, the trigger block 302a moves, thereby compressing the elastic member 302b. And as the trigger block 302a moves, the sealing end 302a-2 of the trigger block 302a also moves simultaneously until the sealing ring 303b is deformed and completely seals the valve port 303a-1. At this time, the telescopic pipe 104 is completely above the trigger block 302a, preventing the elastic member 302b from driving the trigger block 302a to rebound, so as to continuously block the valve port 303a-1, thus completing the blocking of the smoking pipe 304, enabling this device to stop the work of the smoking pipe 304 in time after stopping work, avoiding the problem that the smoking pipe 304 of a single device cannot be stopped when the continuous exhaust duct is operating collectively or the problem of needing to manually close the smoking pipe 304 of a single device, and avoiding the problem that the staff forgets to stop the smoking pipe 304 after stopping work.
[0044] In addition, in order to provide a concise description of the exemplary embodiments, not all features of the actual embodiments may be described (i.e., those features that are not relevant to the currently considered best mode of implementing the present invention or those features that are not relevant to implementing the present invention).
[0045] It should be understood that in the development process of any actual implementation, such as in any engineering or design project, a large number of specific implementation decisions may be made. Such development efforts may be complex and time-consuming, but for those ordinary technicians who benefit from this disclosure, without excessive experimentation, the development efforts will be a routine work of design, manufacturing, and production.
[0046] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.
Claims
1. A restriction structure, characterized in that: include, A main body component (100) comprises a mounting shaft (101), a cantilever (102), a rotating block (103) and a telescopic tube (104), wherein the cantilever (102) is fixedly connected to the rotating block (103), the rotating block (103) is arranged on the mounting shaft (101), and the telescopic tube (104) is arranged on the cantilever (102) and is movably connected to the rotating block (103); The adjustment assembly (200) comprises a rotation limiting member (201), a telescopic limiting member (202) and a limiting hole (203); the rotation limiting member (201) is arranged in the rotation block (103); the telescopic limiting member (202) is arranged in the rotation block (103); the limiting hole (203) is opened on the installation shaft (101) and cooperates with the rotation limiting member (201) and the telescopic limiting member (202).
2. The limiting structure according to claim 1, characterized in that: The rotation limiting member (201) comprises a braking trigger member (201a) and a rotation braking member (201b); the braking trigger member (201a) is arranged on one end of the telescopic tube (104) extending into the rotation block (103); the rotation braking member (201b) is arranged in the rotation block (103) and cooperates with the braking trigger member (201a).
3. The limiting structure according to claim 2, characterized in that: The rotating brake component (201b) comprises a propulsion block (201b-1), a brake rod (201b-2) and a first spring (201b-3); the propulsion block (201b-1) is arranged in the rotating block (103); the brake rod (201b-2) is fixedly connected to the propulsion block (201b-1); the first spring (201b-3) is fixedly connected to the inner wall of the rotating block (103) and the propulsion block (201b-1); and the brake rod (201b-2) cooperates with the limiting hole (203).
4. The limiting structure according to claim 3, characterized in that: The propulsion block (201b-1) is provided with a propulsion groove (201b-1a), and the propulsion groove (201b-1a) cooperates with the inclined surface (201a-1) on the brake triggering member (201a).
5. The limiting structure according to claim 4, characterized in that: The telescopic limiting member (202) comprises a telescopic braking member (202a) and a blocking member (202b); the telescopic braking member (202a) is arranged in the rotating block (103) and cooperates with the braking trigger member (201a); the blocking member (202b) is arranged in the rotating block (103) and cooperates with the limiting hole (203) and the telescopic braking member (202a).
6. The limiting structure according to claim 5, characterized in that: The telescopic brake component (202a) comprises a limit rod (202a-1) and a moving block (202a-2); the limit rod (202a-1) is fixedly connected to the moving block (202a-2); one end of the limit rod (202a-1) away from the moving block (202a-2) is a brake end (202a-1a); and the brake end (202a-1a) cooperates with a spherical groove (201a-2) provided on the brake trigger component (201a).
7. The limiting structure according to claim 6, characterized in that: The blocking member (202b) comprises a second spring (202b-1), an extrusion block (202b-2) and a spherical end (202b-3); the second spring (202b-1) is fixedly connected inside the rotating block (103) and fixedly connected to the extrusion block (202b-2); and the spherical end (202b-3) is arranged at one end of the extrusion block (202b-2) away from the second spring (202b-1).
8. The limiting structure according to claim 7, characterized in that: The extrusion block (202b-2) is provided with a movable groove (202b-2a), and the movable groove (202b-2a) corresponds in shape to an end of the moving block (202a-2) away from the limiting rod (202a-1).
9. A cantilever wire feeder, characterized in that: The invention comprises the restriction structure according to any one of claims 1 to 8, and The control assembly (300) comprises a support member (301), a trigger member (302) and a sealing member (303); the support member (301) is arranged in a smoking pipe (304) fixedly connected to and communicating with the telescopic pipe (104); the trigger member (302) is arranged in the support member (301); and the sealing member (303) is arranged in the smoking pipe (304).
10. The cantilever wire feeder according to claim 9, characterized in that: The support member (301) comprises a support rod (301a) and a support tube (301b), wherein the support rod (301a) is fixedly connected to the inner wall of the smoking tube (304) and the support tube (301b), and the trigger member (302) comprises a trigger block (302a) and an elastic member (302b), wherein the trigger block (302a) comprises a trigger end (302a-1) and a sealing end (302a-2), wherein the trigger end (302a-1) is arranged at one end of the trigger block (302a) extending into the telescopic tube (104) and cooperating with the telescopic tube (104), and the sealing end (302a-2) is arranged The support tube (301b) is extended outwardly from the end away from the trigger end (302a-1), the elastic member (302b) is arranged in the trigger block (302a) and is fixedly connected to the support tube (301b), the sealing member (303) comprises a flue block (303a) arranged on the inner wall of the smoking pipe (304) and a sealing ring (303b) arranged on the flue block (303a), the flue block (303a) and the sealing end (302a-2) have corresponding shapes and are symmetrically arranged to form a valve port (303a-1), and the sealing ring (303b) cooperates with the sealing end (302a-2).