CN212444944U - Locking device for overhauling main steam valve of steam turbine - Google Patents
Locking device for overhauling main steam valve of steam turbine Download PDFInfo
- Publication number
- CN212444944U CN212444944U CN202021288342.5U CN202021288342U CN212444944U CN 212444944 U CN212444944 U CN 212444944U CN 202021288342 U CN202021288342 U CN 202021288342U CN 212444944 U CN212444944 U CN 212444944U
- Authority
- CN
- China
- Prior art keywords
- steam valve
- screw
- main steam
- lead screw
- screw rod
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Control Of Turbines (AREA)
Abstract
The utility model discloses a steam turbine main steam valve overhauls and uses locking device relates to power plant steam turbine technical field, the device includes at least a set of loading board and connects the spliced pole between a set of loading board, loading board and spliced pole are equipped with one or more screw respectively, the butt end of first lead screw and second lead screw passes screw and the main steam disk seat on the loading board that corresponds separately on the screw of second steam valve wall butt third lead screw and fourth lead screw respectively and the butt end passes screw and the main steam disk seat on the spliced pole on first steam valve wall butt. The utility model discloses in, thereby through the displacement of restriction main steam valve seat restriction main steam valve when main steam valve overhauls, can not produce extra power and moment to the equipment interface because of the displacement of main steam valve when guaranteeing to overhaul.
Description
Technical Field
The utility model relates to a power plant steam turbine technical field particularly, relates to a steam turbine main steam valve overhauls and uses locking device.
Background
In thermal power plants and nuclear power plants, steam turbines are key equipment for converting thermal energy into mechanical energy. In the thermodynamic system of the steam turbine, the main valve is an important component of the whole steam turbine steam inlet system. The main valve is installed at a high pressure steam inlet side of the steam turbine, and a spring bracket is generally provided near the main valve for closing the main valve in order to absorb thermal expansion of the high temperature steam pipe. The floating main valve can be displaced during maintenance, and the displacement can damage an equipment interface. The displacement of the main valve will have a certain force on the equipment interface in the maintenance state, and this force will damage the equipment, which is in contradiction with the technical regulation that the installation and maintenance required by the steam turbine manufacturer must be carried out in the stress-free state.
Referring to fig. 1, a main steam valve seat of the prior art includes a first steam valve wall and a second steam valve wall vertically connected to a middle portion of the first steam valve wall; in general, when a main throttle valve of a steam turbine is overhauled, a field overhaul unit generally takes temporary measures, a manufacturer does not give professional technical guidance, the field is mostly constructed by profile steel, holes are directly punched in the profile steel, no relevant technical specification exists, and no specific requirement and guidance are provided for limiting displacement and direction. The displacement of main steam valve seat when overhauing can lead to the power and the moment to the pipeline port under the maintenance state of shutting down, and power and moment under this kind of cold attitude can produce certain effort to the equipment with the pipeline interface, can't satisfy the requirement of some steam turbines unstressed installation and maintenance. Moreover, temporary measures set on site by a construction unit have the problems of lack of standardization in design and construction, and potential safety hazards can be generated; and the design of locking angle and allowable displacement is not standardized, so that the installation precision is low, the air leakage of the door rod is increased, and the safety and the economy of the unit are threatened.
SUMMERY OF THE UTILITY MODEL
In order to overcome above-mentioned problem or solve above-mentioned problem at least partially, the embodiment of the utility model provides a steam turbine main steam valve overhauls uses locking device, thereby through the displacement of restriction main steam valve seat restriction main steam valve when main steam valve overhauls, can not produce extra power and moment to the equipment interface because of the displacement of main steam valve when guaranteeing to overhaul.
The embodiment of the utility model is realized like this:
the utility model provides a steam turbine main steam valve overhauls and uses locking device, include at least a set of loading board and connect the spliced pole between a set of loading board, loading board and spliced pole are equipped with one or more screw respectively, two loading boards are connected with first lead screw and second lead screw respectively, be equipped with the screw with screw hole adaptation on first lead screw and the second lead screw, the butt end of first lead screw and second lead screw passes screw on the loading board that corresponds separately and second steam valve wall butt on the steam valve seat respectively, be connected with third lead screw and fourth lead screw on the spliced pole, also be equipped with the screw with screw hole adaptation on third lead screw and the fourth lead screw, the butt end of third lead screw and fourth lead screw passes screw on the spliced pole and first steam valve wall butt on the steam valve seat respectively.
The design principle is as follows: through long-term research and practice, the applicant of the application finds that in the prior art, the displacement of the main steam valve seat during maintenance can cause force and moment on a pipeline port in a shutdown maintenance state, and the force and the moment in a cold state can generate certain acting force on equipment connected with a pipeline, so that the stress-free installation and maintenance requirements of some steam turbines cannot be met. Moreover, temporary measures set on site by a construction unit have the problems of lack of standardization in design and construction, and potential safety hazards can be generated; and the design of locking angle and allowable displacement is not standardized, so that the installation precision is low, the air leakage of the door rod is increased, and the safety and the economy of the unit are threatened. In view of the above, the present application provides a locking device for overhauling a main steam valve of a steam turbine;
when the locking device is used, the locking device is aligned to a main steam valve seat after being assembled, the first lead screw and the second lead screw are rotated to enable the first lead screw and the second lead screw to approach the second steam valve wall until the first lead screw abuts against the second steam valve wall, at the moment, the first lead screw and the second lead screw clamp and fix the second steam valve wall, the third lead screw and the fourth lead screw are rotated to enable the third lead screw and the fourth lead screw to approach the first steam valve wall until the third lead screw abuts against the first steam valve wall, and the first steam valve wall and the second steam valve wall are limited through the first lead screw, the second lead screw, the third lead screw and the fourth lead screw so as to fix the main steam valve seat; the device has a simple structure, is convenient to operate and adjust, fixes the main steam valve seat through the screw rod, can be detached when the main steam valve seat operates, can be installed when the main steam valve needs to be overhauled, and cannot cause any influence on a normally operating main steam pipeline; the bearing plate and the connecting column can be provided with a plurality of screw holes due to the design of threaded connection, the position of the screw rod is adjusted according to the specific situation on site, and the operation is convenient for site construction; the locking effect is good, the locking is carried out from the transverse direction and the longitudinal direction, and the safety and the reliability of the main steam valve seat in an early locking state are ensured.
The utility model discloses an in some embodiments, a steam turbine main steam valve overhauls and uses locking device, the operating end of first lead screw, second lead screw, third lead screw and or fourth lead screw is connected with the handle.
In some embodiments of the present invention, a locking device for repairing a main steam valve of a steam turbine, wherein an elastic pad is connected to a butt end of the first lead screw, the second lead screw, the third lead screw and/or the fourth lead screw.
The utility model discloses an in some embodiments, a steam turbine main steam valve overhauls and uses locking device, a set of loading board include two loading boards, and two loading board symmetries set up.
In some embodiments of the present invention, a locking device for steam turbine main steam valve maintenance, the central lines of the screw holes on the two bearing plates coincide.
In some embodiments of the present invention, a locking device for steam turbine main steam valve maintenance, the screw holes on the connecting column are at the same level.
In some embodiments of the present invention, a locking device for steam turbine main steam valve maintenance, the position of the screw hole on two bearing plates is higher than the position of the screw hole on the connecting column.
In some embodiments of the present invention, a locking device for steam turbine main steam valve maintenance, the position of the screw hole on two bearing plates is lower than the position of the screw hole on the connecting column.
The utility model discloses an in some embodiments, a steam turbine main steam valve overhauls uses locking device, the distance between the loading board is greater than the width of first steam valve wall, when having a plurality of screws on the spliced pole, and the distance between two arbitrary screws is less than the width of first steam valve wall.
The utility model discloses an in some embodiments, a steam turbine main steam valve overhauls and uses locking device, spliced pole and loading board are detachable connection.
The embodiment of the utility model provides an at least, have following advantage or beneficial effect:
after the locking device is assembled, the locking device is aligned with a main steam valve seat and placed, the first lead screw and the second lead screw are rotated to enable the first lead screw and the second lead screw to approach the second steam valve wall until the first lead screw abuts against the second steam valve wall, at the moment, the first lead screw and the second lead screw clamp and fix the second steam valve wall, the third lead screw and the fourth lead screw are rotated to enable the third lead screw and the fourth lead screw to approach the first steam valve wall until the third lead screw abuts against the first steam valve wall, and the first steam valve wall and the second steam valve wall are limited through the first lead screw, the second lead screw, the third lead screw and the fourth lead screw so as to fix the main steam valve seat;
the device has a simple structure, is convenient to operate and adjust, fixes the main steam valve seat through the screw rod, can be detached when the main steam valve seat operates, can be installed when the main steam valve needs to be overhauled, and cannot cause any influence on a normally operating main steam pipeline;
the device is convenient to adjust, and due to the design of threaded connection, the bearing plate and the connecting column can be provided with a plurality of screw holes, so that the position of the screw rod is adjusted according to the specific situation on site to carry out operation, and the site construction operation is facilitated;
the locking device has good locking effect, and can lock from the transverse direction and the longitudinal direction, thereby ensuring the safety and reliability of the main steam valve seat in the early locking state.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
FIG. 1 is a schematic structural view of a main steam valve seat in the prior art;
fig. 2 is a schematic structural view of an embodiment of the locking device for overhauling the main steam valve of the steam turbine of the present invention;
fig. 3 is the utility model relates to a steam turbine main steam valve overhauls with locking device locking main steam valve seat's structural schematic.
Icon: 1-main steam valve seat, 11-first steam valve wall, 12-second steam valve wall, 2-bearing plate, 3-connecting column, 4-first screw rod, 5-second screw rod, 6-third screw rod, 7-fourth screw rod, 8-handle and 9-elastic pad.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
In the description of the embodiments of the present invention, it should be noted that if the position or positional relationship indicated by the term "middle" or the like is based on the position or positional relationship shown in the drawings, or the position or positional relationship that the utility model is usually placed when using, it is only for convenience of description and simplification of the description, but it is not indicated or suggested that the device or element to be referred to must have a specific position, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.
Furthermore, the term "horizontal" and the like, if present, does not require that the components be absolutely horizontal or overhanging, but may be slightly inclined.
In the description of the embodiments of the present invention, "a plurality" means at least 2.
In the description of the embodiments of the present invention, it should be further noted that unless explicitly stated or limited otherwise, the terms "provided" and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.
Example 1
Referring to fig. 1-3, the embodiment provides a locking device for overhauling a main steam valve of a steam turbine, which comprises at least one group of bearing plates 2 and a connecting column 3 connected between the group of bearing plates 2, wherein the bearing plates 2 and the connecting column 3 are respectively provided with one or more screw holes, the two bearing plates 2 are respectively connected with a first screw rod 4 and a second screw rod 5, the first screw rod 4 and the second screw rod 5 are provided with threads matched with the screw holes, the abutting ends of the first screw rod 4 and the second screw rod 5 respectively penetrate through the screw holes on the corresponding bearing plates 2 to abut against a second steam valve wall 12 on the main steam valve seat 1, the connecting column 3 is connected with a third screw rod 6 and a fourth screw rod 7, the third screw rod 6 and the fourth screw rod 7 are also provided with threads matched with the screw holes, and the abutting ends of the third screw rod 6 and the fourth screw rod 7 respectively penetrate through the screw holes on the connecting column 3 to abut against a first steam valve wall 11 on the main steam valve seat 1.
The design principle is as follows: through long-term research and practice, the applicant of the present application finds that, in the prior art, the displacement of the main steam valve seat 1 during maintenance can cause force and moment on a pipeline port in a shutdown maintenance state, and the force and moment in a cold state can generate certain acting force on equipment connected with a pipeline, so that the requirements of stress-free installation and maintenance of some steam turbines cannot be met. Moreover, temporary measures set on site by a construction unit have the problems of lack of standardization in design and construction, and potential safety hazards can be generated; and the design of locking angle and allowable displacement is not standardized, so that the installation precision is low, the air leakage of the door rod is increased, and the safety and the economy of the unit are threatened. In view of the above, the present application provides a locking device for overhauling a main steam valve of a steam turbine;
when the locking device is used, the locking device is aligned to a main steam valve seat 1 after being assembled, the first lead screw 4 and the second lead screw 5 are rotated to enable the first lead screw 4 and the second lead screw to approach towards a second steam valve wall 12 until the first lead screw abuts against the second steam valve wall 12, at the moment, the first lead screw 4 and the second lead screw 5 clamp and fix the second steam valve wall 12, the third lead screw 6 and the fourth lead screw 7 are rotated to enable the third lead screw 6 and the fourth lead screw 7 to approach towards the first steam valve wall 11 until the third lead screw abuts against the first steam valve wall 11, and the first steam valve wall 11 and the second steam valve wall 12 are limited through the first lead screw 4, the second lead screw 5, the third lead screw 6 and the fourth lead screw 7 so as to fix the main steam valve seat 1; the device has a simple structure, is convenient to operate and adjust, fixes the main steam valve seat 1 through the screw rod, can be detached when the main steam valve seat 1 operates, can be installed when the main steam valve needs to be overhauled, and cannot cause any influence on a normally operating main steam pipeline; the adjustment is convenient, the design of threaded connection can be realized, a plurality of screw holes can be formed in the bearing plate 2 and the connecting column 3, the position of the screw rod is adjusted according to the specific situation on site, and the site construction operation is convenient; the locking effect is good, the locking is carried out from the transverse direction and the longitudinal direction, and the safety and the reliability of the main steam valve seat 1 in an early locking state are ensured.
Example 2
Referring to fig. 2, the present embodiment is a further improvement on embodiment 1, and the difference between the present embodiment and embodiment 1 is that in the present embodiment, the operating end of the first lead screw 4, the second lead screw 5, the third lead screw 6 and/or the fourth lead screw 7 is connected to a handle 8. The first screw rod 4, the second screw rod 5, the third screw rod 6 and/or the fourth screw rod 7 are driven to rotate through the rotating handle 8, so that manual operation is facilitated, and labor is saved.
Further, considering that the main steam valve seat 1 is inevitably damaged after the lead screw is abutted to the main steam valve seat 1 for multiple times, in view of the above, the elastic pad 9 is arranged at the abutting end of the first lead screw 4, the second lead screw 5, the third lead screw 6 and/or the fourth lead screw 7, the elastic pad 9 can be made of rubber, the elastic pad 9 has buffering force, the contact area between the lead screw and the main steam valve seat 1 is increased, the main steam valve seat 1 is effectively protected from being damaged, and the service life of the device is prolonged.
Illustratively, a set of bearing plate 2 includes two bearing plates 2, and two bearing plates 2 are arranged symmetrically, when making the mould, be convenient for integrated into one piece.
Exemplarily, the center lines of the screw holes of the two bearing plates 2 coincide, and the purpose of this is to enable the first lead screw 4 and the second lead screw 5 to be accurately clamped and fixed to the second steam valve wall 12.
Exemplarily, the screw holes on the connecting column 3 are at the same horizontal height, the screw holes on the two bearing plates 2 are higher or lower than the screw holes on the connecting column 3, exemplarily, the distance between the bearing plates 2 is greater than the width of the first steam valve wall 11, and when the connecting column 3 has a plurality of screw holes, the distance between any two screw holes is less than the width of the first steam valve wall 11. The purpose of this is to make the first screw 4 and the third screw 6 arranged in a staggered manner and to facilitate the fixing of the main steam valve seat 1.
Exemplarily, the connecting column 3 and the bearing plate 2 are detachably connected, so that the carrying is convenient.
To sum up, the embodiment of the utility model provides a steam turbine main steam valve overhauls and uses locking device, during the use, will assemble the locking device of this application after aim at main steam valve seat 1 and place, rotatory first lead screw 4 and second lead screw 5 make first lead screw 4 and second lead screw near to second steam valve wall 12 until conflict second steam valve wall 12, at this moment, first lead screw 4 and second lead screw 5 carry out centre gripping fixed to second steam valve wall 12, rotate third lead screw 6 and fourth lead screw 7 again, make third lead screw 6 and fourth lead screw 7 near to first steam valve wall 11 until conflict first steam valve wall 11, carry out spacing thus to first steam valve wall 11 and second steam valve wall 12 through first lead screw 4, second lead screw 5 third lead screw 6 and fourth lead screw 7 and fix main steam valve seat 1;
the device has a simple structure, is convenient to operate and adjust, fixes the main steam valve seat 1 through the screw rod, can be detached when the main steam valve seat 1 operates, can be installed when the main steam valve needs to be overhauled, and cannot cause any influence on a normally operating main steam pipeline;
the device is convenient to adjust, and due to the design of threaded connection, a plurality of screw holes can be formed in the bearing plate 2 and the connecting column 3, so that the position of the screw rod is adjusted to work according to the specific situation on site, and the site construction work is facilitated;
the locking device has good locking effect, and can lock from the transverse direction and the longitudinal direction, thereby ensuring the safety and reliability of the main steam valve seat 1 in the early locking state.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
It will be evident to those skilled in the art that the present application is not limited to the details of the foregoing illustrative embodiments, and that the present application may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Claims (10)
1. A locking device for overhauling a main steam valve of a steam turbine is characterized by comprising at least one group of bearing plates and a connecting column connected between the bearing plates, wherein one group of the bearing plates comprises two bearing plates, the bearing plate and the connecting column are respectively provided with one or more screw holes, the two bearing plates are respectively connected with a first screw rod and a second screw rod, the first screw rod and the second screw rod are provided with threads matched with the screw holes, the abutting ends of the first screw rod and the second screw rod respectively penetrate through the screw holes on the corresponding bearing plates and abut against the second steam valve wall on the main steam valve seat, a third screw rod and a fourth screw rod are connected on the connecting column, threads matched with the screw holes are also arranged on the third screw rod and the fourth screw rod, and the butt joint ends of the third screw rod and the fourth screw rod respectively penetrate through the screw hole on the connecting column to be in butt joint with the first steam valve wall on the main steam valve seat.
2. The locking device for overhauling the main steam valve of the steam turbine as claimed in claim 1, wherein the operating ends of the first lead screw, the second lead screw, the third lead screw and the fourth lead screw are connected with a handle.
3. The locking device for overhauling the main steam valve of the steam turbine as claimed in claim 1, wherein the abutting ends of the first screw rod, the second screw rod, the third screw rod and the fourth screw rod are connected with elastic pads.
4. The steam turbine main steam valve servicing locking apparatus of claim 1, wherein two of said bearing plates are symmetrically disposed.
5. The steam turbine main steam valve servicing locking apparatus of claim 2, wherein the center lines of the threaded holes in both of said bearing plates coincide.
6. The steam turbine main steam valve service locking device of claim 1, wherein the screw holes of the connecting column are at the same level.
7. The steam turbine main steam valve service locking device as claimed in claim 1, wherein the screw holes of said two bearing plates are higher than the screw holes of the connecting column.
8. The steam turbine main steam valve service locking device as claimed in claim 1, wherein the screw holes of said two bearing plates are located lower than the screw holes of the connecting column.
9. The steam turbine main steam valve servicing locking apparatus of claim 1, wherein the distance between said bearing plates is greater than the width of said first steam valve wall, and when a plurality of said threaded holes are provided in the connecting column, the distance between any two of said threaded holes is less than the width of said first steam valve wall.
10. The locking device for overhauling a main steam valve of a steam turbine as claimed in claim 1, wherein the connecting column is detachably connected with the bearing plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021288342.5U CN212444944U (en) | 2020-07-01 | 2020-07-01 | Locking device for overhauling main steam valve of steam turbine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021288342.5U CN212444944U (en) | 2020-07-01 | 2020-07-01 | Locking device for overhauling main steam valve of steam turbine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN212444944U true CN212444944U (en) | 2021-02-02 |
Family
ID=74484240
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202021288342.5U Active CN212444944U (en) | 2020-07-01 | 2020-07-01 | Locking device for overhauling main steam valve of steam turbine |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN212444944U (en) |
-
2020
- 2020-07-01 CN CN202021288342.5U patent/CN212444944U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7896302B2 (en) | Jet pump sensing line T-bolt clamp assembly | |
| KR20180026129A (en) | Pipe line alignment jig for welding equipment | |
| US6435839B1 (en) | Jet pump sensing line clamp assembly and methods | |
| US20080296470A1 (en) | Method and apparatus for repairing a jet pump line support | |
| CN212444944U (en) | Locking device for overhauling main steam valve of steam turbine | |
| JP5188679B2 (en) | Method and apparatus for repairing the attachment of a jet pump riser brace to a reactor vessel pad in a nuclear reactor | |
| CN219220708U (en) | Fracturing pump valve box angle adjustment bearing structure | |
| CN106505805B (en) | The installation method of generator unit stator portion, nuclear power plant set | |
| CN109379032A (en) | It is a kind of for protecting the frame fixed structure of solar panel | |
| CN206093215U (en) | Pipeline clip utensil | |
| CN210757508U (en) | Transformer gas relay dismouting appurtenance | |
| CN212319145U (en) | Natural gas line protective structure | |
| CN205129717U (en) | Flange Gap Expander | |
| CN209069184U (en) | One kind is for optical cable static state radius of curvature assisted tester in rapid verification substation | |
| CN209912399U (en) | Mosaic module capable of being spliced | |
| CN216803268U (en) | Valve dismouting appurtenance | |
| CN220706756U (en) | Water supply and drainage pipeline | |
| CN215215187U (en) | Auxiliary positioning device for mounting flange and valve of secondary water supply equipment | |
| CN217572631U (en) | Asymmetric test fixture of blade root bolt | |
| CN220647008U (en) | Pipeline positioning protection mechanism | |
| CN220957035U (en) | High-pressure speed-regulating valve rod anti-drop device of steam turbine | |
| CN205111650U (en) | Cooling turbine is experimental with integration anchor clamps | |
| CN214249050U (en) | Special lossless clamp | |
| CN219933738U (en) | Gas pressure regulating box convenient to overhaul | |
| CN218877510U (en) | Quick-assembly locking device for navigation mark body |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |