CN113488325A - Low-noise dry-type transformer - Google Patents
Low-noise dry-type transformer Download PDFInfo
- Publication number
- CN113488325A CN113488325A CN202110752629.1A CN202110752629A CN113488325A CN 113488325 A CN113488325 A CN 113488325A CN 202110752629 A CN202110752629 A CN 202110752629A CN 113488325 A CN113488325 A CN 113488325A
- Authority
- CN
- China
- Prior art keywords
- damping
- dry
- type transformer
- transformer body
- fixedly connected
- 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.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/33—Arrangements for noise damping
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Regulation Of General Use Transformers (AREA)
Abstract
The invention belongs to the field of transformers, and discloses a low-noise dry-type transformer which comprises a dry-type transformer body, wherein the bottom of the dry-type transformer body is fixedly connected with a fixing plate, the bottom of the fixing plate is connected with a plurality of uniformly distributed damping devices, the bottoms of the damping devices are fixedly connected with mounting plates, and sound insulation plates are arranged on the inner side of the box wall of the dry-type transformer body. This scheme buffers the vibrations of the outside production of dry-type transformer body through damping device, and then falls the noise of making an uproar to the dry-type transformer body, through the inside acoustic celotex board of box, biography sound hole and wave form noise damping layer, carries out the amortization to the inside noise that produces of dry-type transformer body and falls the noise, and then falls the noise through the amortization to the dry-type transformer body outside and inside, reduces the noise that the dry-type transformer body produced to the at utmost, avoids influencing resident's normal life work and rest on every side.
Description
Technical Field
The present invention relates to the field of transformers, and more particularly, to low noise dry transformers.
Background
Dry transformers are widely used in local lighting, high-rise buildings, airports, wharf CNC machines and the like, and simply referred to as dry transformers are transformers in which the core and the winding are not immersed in insulating oil.
The dry type transformer can generate a large amount of noise during operation, the noise of the transformer can be roughly divided into internal noise and external noise, the noise of the transformer is generated in the transformer by more than 80%, the most of the internal noise is generated in an iron core of the transformer, most of the internal noise is generated in the operation process of the structure in the transformer, the external noise of the transformer mainly comes from vibration of a machine body during operation, and the noise generated during long-time operation of the transformer can influence normal daily lives and rest of surrounding residents, so that the low-noise dry type transformer is provided.
Disclosure of Invention
The invention aims to solve the defects in the prior art and provides a low-noise dry-type transformer.
In order to solve the above problems, the present invention adopts the following technical solutions.
Low noise dry-type transformer, including the dry-type transformer body, the bottom fixedly connected with fixed plate of dry-type transformer body, the bottom of fixed plate is connected with a plurality of evenly distributed's damping device, damping device's bottom fixedly connected with mounting panel, the tank wall inboard of dry-type transformer body is provided with the acoustic celotex board, the acoustic celotex board falls the chamber of making an uproar with constituting between its and the tank wall of dry-type transformer body, it is provided with the wave form amortization layer to fall the intracavity, a plurality of biography sound holes have been seted up on the acoustic celotex board.
As a further scheme of the invention:
the damping device comprises a connecting block, the top of the connecting block is fixedly connected with the bottom of a fixing plate, the bottom of the connecting block is connected with a first damping assembly, a damping shell is developed at the top of the mounting plate, the bottom end of the first damping assembly penetrates through and extends into the damping shell, the first damping assembly is connected with a fixing ring in the damping shell, the left surface, the right surface, the front surface and the back surface of the fixing ring are hinged with push-pull inclined rods, one end, away from the first damping assembly, of each push-pull inclined rod is hinged with a push-pull block, the left surface, the right surface, the front surface and the back surface of the first damping assembly are provided with second damping assemblies, the four second damping assemblies are all mounted on the inner bottom wall of the damping shell, and the four second damping assemblies are respectively connected with the four push-pull blocks.
As a further scheme of the invention:
the bottom fixedly connected with guide block of push-and-pull piece, the guide way has been seted up on the interior diapire of shock attenuation shell, guide block and guide way sliding connection.
As a further scheme of the invention:
the second damping assembly is the same as the first damping assembly in structure, the second damping assembly is transversely arranged, and the first damping assembly is vertically arranged.
As a further scheme of the invention:
fixedly connected with auxiliary spring on the interior diapire of shock attenuation shell, auxiliary spring is connected with first damper.
As a further scheme of the invention:
first damper includes the damper cylinder, the top and the connecting block fixed connection of damper cylinder, the inside that runs through and extend to the shock attenuation shell is established to the bottom of damper cylinder, solid fixed ring cover establish on the damper cylinder and with damper cylinder fixed connection, fixedly connected with damping spring on the interior roof of damper cylinder, damping spring's bottom fixedly connected with snubber block, two bumper block's two shock attenuation poles of bottom fixedly connected with, two the bumper bar runs through the inner diapire fixed connection of damper cylinder and auxiliary spring and shock attenuation shell respectively.
As a further scheme of the invention:
the equal fixedly connected with guide bar in the left and right sides of connecting block bottom, the bottom of guide bar run through and extend to in the shock attenuation shell and with first damper assembly's shock attenuation section of thick bamboo fixed connection.
As a further scheme of the invention:
the sound transmission holes are filled with sound absorption cotton, and the wave-shaped sound attenuation layer is made of foam rubber.
Compared with the prior art, the invention has the advantages that:
This scheme buffers the vibrations of the outside production of dry-type transformer body through damping device, and then falls the noise of making an uproar to the dry-type transformer body, through the inside acoustic celotex board of box, biography sound hole and wave form noise damping layer, carries out the amortization to the inside noise that produces of dry-type transformer body and falls the noise, and then falls the noise through the amortization to the dry-type transformer body outside and inside, reduces the noise that the dry-type transformer body produced to the at utmost, avoids influencing resident's normal life work and rest on every side.
Drawings
FIG. 1 is a schematic structural view of the present invention;
FIG. 2 is a schematic view of a waveform silencing layer structure according to the present invention;
FIG. 3 is a front sectional view of the shock absorbing device of FIG. 1 according to the present invention;
FIG. 4 is a top view of the first shock absorbing assembly attached to the second shock absorbing assembly in accordance with the present invention;
FIG. 5 is an enlarged view of the invention at A in FIG. 2.
The reference numbers in the figures illustrate:
1. a dry-type transformer body; 2. a fixing plate; 3. a damping device; 31. connecting blocks; 32. a first dampening member; 321. a damper cylinder; 322. a damping spring; 323. a damper block; 324. a shock-absorbing lever; 33. a shock-absorbing shell; 34. a fixing ring; 35. push-pull diagonal rods; 36. a push-pull block; 37. a second dampening member; 4. mounting a plate; 5. a sound insulating board; 6. a noise reduction cavity; 7. a waveform silencing layer; 8. a sound transmission hole; 9. a guide block; 10. a guide groove; 11. an auxiliary spring; 12. a guide bar; 13. and (5) sound absorption cotton.
Detailed Description
The technical solution in 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; it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and all other embodiments obtained by those skilled in the art without any inventive work are within the scope of the present invention.
Referring to fig. 1-5, a low noise dry type transformer includes a dry type transformer body 1, a fixing plate 2 is fixedly connected to the bottom of the dry type transformer body 1, a plurality of damping devices 3 are uniformly distributed and connected to the bottom of the fixing plate 2, a mounting plate 4 is fixedly connected to the bottom of the damping devices 3, a sound insulating plate 5 is disposed on the inner side of the tank wall of the dry type transformer body 1, a noise reduction cavity 6 is formed between the sound insulating plate 5 and the tank wall of the dry type transformer body 1, a waveform noise reduction layer 7 is disposed in the noise reduction cavity 6, and a plurality of sound transmission holes 8 are disposed on the sound insulating plate 5, according to the scheme, the vibration generated outside the dry type transformer body 1 is buffered by the damping devices 3, and then the noise reduction is performed on the dry type transformer body 1, and the noise generated inside the dry type transformer body 1 is reduced by the sound insulating plate 5, the sound transmission holes 8 and the waveform noise reduction layer 7 inside the tank, and then through the noise reduction to the outside of dry-type transformer body 1 and inside, reduce the noise that dry-type transformer body 1 produced to the at utmost, avoid influencing resident's around normal life work and rest.
Specifically, the damping device 3 includes a connecting block 31, the top of the connecting block 31 is fixedly connected with the bottom of the fixing plate 2, the bottom of the connecting block 31 is connected with a first damping assembly 32, a damping shell 33 is developed on the top of the mounting plate 4, the bottom end of the first damping assembly 32 penetrates and extends into the damping shell 33, a fixing ring 34 is connected on the first damping assembly 32 and is positioned inside the damping shell 33, the left, right, front and back surfaces of the fixing ring 34 are hinged with push-pull inclined rods 35, one end of each push-pull inclined rod 35 away from the first damping assembly 32 is hinged with a push-pull block 36, the left, right, front and back surfaces of the first damping assembly 32 are provided with second damping assemblies 37, four second damping assemblies 37 are all mounted on the inner bottom wall of the damping shell 33, the four second damping assemblies 37 are respectively connected with the four push-pull blocks 36, when the damping device 3 is in use, part of the force is buffered and offset through the first damping assembly 32, the other part of the force is converted into the horizontal direction through the fixed ring 34, the push-pull inclined rod 35 and the push-pull block 36, and the part of the force is buffered and offset through the second damping assembly 37, so that good damping and noise reduction effects are achieved.
Wherein, the bottom fixedly connected with guide block 9 of push-and-pull piece 36, seted up guide way 10 on the interior diapire of shock attenuation shell 33, guide block 9 and guide way 10 sliding connection, through mutually supporting of guide block 9 and guide way 10, carry out spacing and direction to push-and-pull piece 36.
In addition, second damper 37 is the same with first damper 32 structure, and second damper 37 is horizontal setting, and first damper 32 is vertical setting, fixedly connected with auxiliary spring 11 on the interior diapire of shock attenuation shell 33, and auxiliary spring 11 is connected with first damper 32, and auxiliary spring 11 can play the cushioning effect to first damper 32, can assist first damper 32 to carry out the shock attenuation simultaneously.
Specifically, the first damping assembly 32 includes a damping cylinder 321, the top end of the damping cylinder 321 is fixedly connected to the connecting block 31, the bottom of the damping cylinder 321 penetrates through and extends to the inside of the damping shell 33, the fixing ring 34 is sleeved on the damping cylinder 321 and is fixedly connected to the damping cylinder 321, the inner top wall of the damping cylinder 321 is fixedly connected to a damping spring 322, the bottom end of the damping spring 322 is fixedly connected to a damping block 323, the bottom of the damping block 323 is fixedly connected to two damping rods 324, the two damping rods 324 respectively penetrate through the damping cylinder 321 and the auxiliary spring 11 and are fixedly connected to the inner bottom wall of the damping shell 33, when the dry-type transformer body 1 vibrates, the damping cylinder 321 in the first damping assembly 32 is driven to move up and down relative to the damping rods 324, so that the damping spring 322 in the damping cylinder 321 is compressed and deformed to offset a part of the force, thereby achieving a damping effect;
Since the first damper assembly 32 and the second damper assembly 37 have the same structure, only the structure of the first damper assembly 32 will be described in detail herein, and the damping principle of the second damper assembly 37 is that after part of the force of the first damper assembly 32 is converted into horizontal direction by the fixing ring 34, the push-pull slant rod 35 and the push-pull block 36, the damper rod 324 in the second damper assembly 37 is pushed by the action of the push-pull block 36, so that the damper block 323 compresses the damper spring 322 to achieve damping and noise reduction.
Wherein, the equal fixedly connected with guide bar 12 of the left and right sides of connecting block 31 bottom, the bottom of guide bar 12 run through and extend to in the damper housing 33 and with first damper assembly 32's damper cylinder 321 fixed connection, can carry out spacing and direction to damper cylinder 321 through guide bar 12.
In addition, sound transmission hole 8 intussuseption is filled with and inhales sound cotton 13, wave form noise damping layer 7 is the foaming adhesive, the noise that produces during dry-type transformer body 1 can pass through sound transmission hole 8 on acoustic celotex board 5 and get into and fall the chamber 6 of making an uproar in, sound absorption cotton 13 can play the supplementary effect of inhaling the sound after the process that sound pierces through sound transmission hole 8, after sound gets into and falls the chamber 6 of making an uproar, again under the absorption of wave form noise damping layer 7 that comprises the foaming adhesive, effectively prevented the noise and propagated towards outdoor, and the foaming adhesive has fine amortization effect, has fire prevention ability simultaneously.
The working principle is as follows: when the dry-type transformer body 1 works, noise generated inside can enter the noise reduction cavity 6 through the sound transmission holes 8 in the sound insulation plate 5, the sound absorption cotton 13 can play a role in assisting sound absorption after the sound penetrates through the sound transmission holes 8, and after the sound enters the noise reduction cavity 6, the noise is effectively prevented from being transmitted outdoors under the absorption of the waveform noise elimination layer 7 formed by foaming adhesive;
and the vibrations of outside production are buffered the vibrations of the outside production of dry-type transformer body 1 through setting up multiunit damping device 3, and then fall the noise to dry-type transformer body 1, specifically do: the fixing plate 2 and the mounting plate 4 are connected into a whole through the connecting blocks 31, the first damping assemblies 32 and the damping shell 33 of the multiple groups of damping devices 3, the vibration direction of the dry-type transformer body 1 is limited in the vertical direction, and when the dry-type transformer body 1 vibrates, the damping cylinder 321 in the first damping assemblies 32 is driven to move up and down relative to the damping rod 324, so that the damping spring 322 in the damping cylinder 321 is compressed and deformed, elastic force is offset on partial stress, and the effects of damping and reducing noise are achieved;
the other part of the stress is converted into the horizontal direction by the fixed ring 34, the push-pull inclined rod 35 and the push-pull block 36, and then the shock absorption rod 324 in the second shock absorption assembly 37 is pushed by the movement of the push-pull block 36, so that the shock absorption block 323 compresses the shock absorption spring 322 to perform buffering and offsetting, and a better shock absorption and noise reduction effect is achieved;
To sum up this scheme is through making an uproar falls with the inside amortization to dry-type transformer body 1 outside, reduces the noise that dry-type transformer body 1 produced to the at utmost, avoids influencing resident's around normal life work and rest.
The foregoing is only a preferred embodiment of the present invention; the scope of the invention is not limited thereto. Any person skilled in the art should be able to cover the technical scope of the present invention by equivalent or modified solutions and modifications within the technical scope of the present invention.
Claims (8)
1. Low noise dry-type transformer, including dry-type transformer body (1), its characterized in that: the utility model discloses a damping device for dry-type transformer, including dry-type transformer body (1), the bottom fixedly connected with fixed plate (2) of dry-type transformer body (1), the bottom of fixed plate (2) is connected with a plurality of evenly distributed's damping device (3), the bottom fixedly connected with mounting panel (4) of damping device (3), the tank wall inboard of dry-type transformer body (1) is provided with acoustic celotex board (5), acoustic celotex board (5) fall the chamber (6) of making an uproar with the constitution between the tank wall of dry-type transformer body (1), it is provided with wave form noise damping layer (7) to fall in chamber (6) of making an uproar, a plurality of biography sound hole (8) have been seted up on acoustic celotex board (5).
2. The low noise dry transformer of claim 1, wherein: the damping device (3) comprises a connecting block (31), the top of the connecting block (31) is fixedly connected with the bottom of the fixing plate (2), the bottom of the connecting block (31) is connected with a first damping component (32), a damping shell (33) is developed at the top of the mounting plate (4), the bottom end of the first damping component (32) penetrates through and extends into the damping shell (33), a fixing ring (34) is connected to the first damping component (32) and is positioned in the damping shell (33), push-pull inclined rods (35) are hinged to the left surface, the right surface, the front surface and the back surface of the fixing ring (34), one end, far away from the first damping component (32), of each push-pull inclined rod (35) is hinged to a push-pull block (36), second damping components (37) are arranged on the left surface, the right surface, the front surface and the back surface of the first damping component (32), and four second damping components (37) are all mounted on the inner bottom wall of the damping shell (33), the four second shock absorption assemblies (37) are respectively connected with the four push-pull blocks (36).
3. The low noise dry transformer of claim 2, wherein: the bottom fixedly connected with guide block (9) of push-and-pull piece (36), guide way (10) have been seted up on the interior diapire of shock attenuation shell (33), guide block (9) and guide way (10) sliding connection.
4. The low noise dry transformer of claim 2, wherein: the structure of the second damping assembly (37) is the same as that of the first damping assembly (32), the second damping assembly (37) is arranged transversely, and the first damping assembly (32) is arranged vertically.
5. The low noise dry transformer of claim 4, wherein: fixedly connected with auxiliary spring (11) on the interior diapire of shock attenuation shell (33), auxiliary spring (11) are connected with first damper (32).
6. The low noise dry transformer of claim 5, wherein: first damper (32) are including damper cylinder (321), the top and connecting block (31) fixed connection of damper cylinder (321), the inside that runs through and extend to damper shell (33) in the bottom of damper cylinder (321), gu fixed ring (34) cover establish on damper cylinder (321) and with damper cylinder (321) fixed connection, fixedly connected with damping spring (322) on the interior roof of damper cylinder (321), the bottom fixedly connected with snubber block (323) of damping spring (322), two bumper rods (324) of the bottom fixedly connected with of snubber block (323), two bumper rods (324) run through the inner bottom wall fixed connection of damper cylinder (321) and auxiliary spring (11) and damper shell (33) respectively.
7. The low noise dry transformer of claim 6, wherein: the equal fixedly connected with guide bar (12) in the left and right sides of connecting block (31) bottom, the bottom of guide bar (12) is run through and is extended to in shock attenuation shell (33) and with damper cylinder (321) fixed connection of first damper (32).
8. The low noise dry transformer of claim 1, wherein: sound absorption cotton (13) are filled in the sound transmission holes (8), and the wave-shaped sound absorption layer (7) is made of foam rubber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110752629.1A CN113488325A (en) | 2021-07-03 | 2021-07-03 | Low-noise dry-type transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110752629.1A CN113488325A (en) | 2021-07-03 | 2021-07-03 | Low-noise dry-type transformer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113488325A true CN113488325A (en) | 2021-10-08 |
Family
ID=77939772
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110752629.1A Pending CN113488325A (en) | 2021-07-03 | 2021-07-03 | Low-noise dry-type transformer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113488325A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114141480A (en) * | 2021-12-27 | 2022-03-04 | 许昌中天宇光电气技术有限公司 | Low-noise dry-type transformer |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204809000U (en) * | 2015-05-22 | 2015-11-25 | 加能(上海)科技股份有限公司 | Dry -type transformer cabinet sound insulation muffler plate |
| KR20160026099A (en) * | 2014-08-29 | 2016-03-09 | 주식회사 군영 | Transformer cover noise reducing device |
| CN208093294U (en) * | 2018-04-26 | 2018-11-13 | 湖南天跃电气有限公司 | Noise reducing type box type transformer |
| CN210722722U (en) * | 2019-11-22 | 2020-06-09 | 重庆润泰电气有限公司 | Noise reduction device for dry-type transformer |
| CN211654500U (en) * | 2020-01-13 | 2020-10-09 | 山东鲁能超越电气有限公司 | Noise reduction structure for amorphous alloy transformer |
| CN212303348U (en) * | 2020-07-17 | 2021-01-05 | 临颍科源电气有限公司 | Novel dry-type transformer |
| CN113012911A (en) * | 2021-03-17 | 2021-06-22 | 高翠娟 | Amorphous alloy is damping and noise reduction frock for transformer |
-
2021
- 2021-07-03 CN CN202110752629.1A patent/CN113488325A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20160026099A (en) * | 2014-08-29 | 2016-03-09 | 주식회사 군영 | Transformer cover noise reducing device |
| CN204809000U (en) * | 2015-05-22 | 2015-11-25 | 加能(上海)科技股份有限公司 | Dry -type transformer cabinet sound insulation muffler plate |
| CN208093294U (en) * | 2018-04-26 | 2018-11-13 | 湖南天跃电气有限公司 | Noise reducing type box type transformer |
| CN210722722U (en) * | 2019-11-22 | 2020-06-09 | 重庆润泰电气有限公司 | Noise reduction device for dry-type transformer |
| CN211654500U (en) * | 2020-01-13 | 2020-10-09 | 山东鲁能超越电气有限公司 | Noise reduction structure for amorphous alloy transformer |
| CN212303348U (en) * | 2020-07-17 | 2021-01-05 | 临颍科源电气有限公司 | Novel dry-type transformer |
| CN113012911A (en) * | 2021-03-17 | 2021-06-22 | 高翠娟 | Amorphous alloy is damping and noise reduction frock for transformer |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114141480A (en) * | 2021-12-27 | 2022-03-04 | 许昌中天宇光电气技术有限公司 | Low-noise dry-type transformer |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110648826A (en) | Noise reduction structure of dry-type transformer | |
| CN211265181U (en) | Noise reduction type dry-type transformer | |
| CN113488325A (en) | Low-noise dry-type transformer | |
| CN214836718U (en) | Diesel generator silencing and damping device | |
| CN211288261U (en) | Efficient circulating water pump shell for steel rolling | |
| CN214534234U (en) | Vibration and noise reduction structure for generator assembly | |
| CN211382611U (en) | Noise-reducing mute fascia gun | |
| CN212562283U (en) | Shockproof noise-reducing composite aluminum alloy floor | |
| CN213211928U (en) | Dry-type transformer noise reduction and shock absorption structure | |
| CN211687849U (en) | Guide rail support frame and elevator | |
| CN210565373U (en) | HL type mounting box for pipeline centrifugal pump with mechanism of making an uproar is fallen | |
| CN108895116B (en) | A kind of electromechanical equipment damping is except device of making an uproar | |
| CN221003618U (en) | Fixing device for damping vibration attenuation and noise reduction of compressor | |
| CN210759546U (en) | Sound-insulation medium-density fiberboard | |
| CN210319235U (en) | Vibration/noise reduction fixing structure | |
| CN212462526U (en) | Electrical cabinet with anti-vibration support structure | |
| CN220353181U (en) | Decorative curtain wall | |
| CN217260315U (en) | EPP connecting cover plate for automobile engine | |
| CN210032556U (en) | Noise reduction structure of building construction platform | |
| CN215350567U (en) | Noise reduction type fascia gun | |
| CN215891408U (en) | Warm ventilation pipe is with shockproof structure in building | |
| CN217682155U (en) | Vacuum pump with vibration/noise reduction function | |
| CN220849847U (en) | Noise reduction device of diesel generating set | |
| CN219316348U (en) | Noise reduction type building construction platform | |
| CN219716458U (en) | Vibration rod noise suppression device for energy-saving construction |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20211008 |
|
| RJ01 | Rejection of invention patent application after publication |