WO2017105311A1 - Deformation resistant filter - Google Patents

Deformation resistant filter Download PDF

Info

Publication number
WO2017105311A1
WO2017105311A1 PCT/SE2016/000068 SE2016000068W WO2017105311A1 WO 2017105311 A1 WO2017105311 A1 WO 2017105311A1 SE 2016000068 W SE2016000068 W SE 2016000068W WO 2017105311 A1 WO2017105311 A1 WO 2017105311A1
Authority
WO
WIPO (PCT)
Prior art keywords
filter
layers
net
frame
pretensioned
Prior art date
Application number
PCT/SE2016/000068
Other languages
French (fr)
Inventor
Bo DOLK-PETERSSON
Original Assignee
Qleanair Scandinavia Ab
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Qleanair Scandinavia Ab filed Critical Qleanair Scandinavia Ab
Priority to JP2018527732A priority Critical patent/JP2018537278A/en
Priority to EP16876138.5A priority patent/EP3389824A4/en
Publication of WO2017105311A1 publication Critical patent/WO2017105311A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/10—Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/30—Particle separators, e.g. dust precipitators, using loose filtering material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
    • B01D53/04—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography with stationary adsorbents
    • B01D53/0407—Constructional details of adsorbing systems
    • B01D53/0415—Beds in cartridges
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/10—Inorganic adsorbents
    • B01D2253/102—Carbon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/10—Inorganic adsorbents
    • B01D2253/106—Silica or silicates
    • B01D2253/108—Zeolites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/06—Polluted air
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2275/00—Filter media structures for filters specially adapted for separating dispersed particles from gases or vapours
    • B01D2275/10—Multiple layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2275/00—Filter media structures for filters specially adapted for separating dispersed particles from gases or vapours
    • B01D2275/50—Stabilised filter material, stabilised by, e.g. structuring, calendering

Definitions

  • the present invention relates to a deformation resistant filter according to the introductory portion of the independent claim.
  • Filters typically consist of a frame like arrangement enclosed on two sides by a net, where a filtering substance is held in the closed space formed by the frame and the net.
  • the substance is often in granulate form, which may set if exposed to shaking and loads. If the net gives way to the load, voids that lacks filter substance may form in the interior of the filter, and the fluid that should have been filtered by the substance may then pass through the filter unfiltered.
  • An object of the invention is therefore to provide a deformation resistant filter which minimizes the risk that voids that lacks filter substance form in the filter.
  • the invention relates to a filter 4a-b comprising at least one cell delimited by a frame element 1, 2a-b and two permeable layers 3, 3a-b.
  • the at least one cell contains a filter substance.
  • the permeable layers 3, 3a-b are attached to the frame in such a way, that the layers are pretensioned, which has the advantage that the permeable layers tend towards a well defined shape, and if the layers are exposed to a load, the pretensioning acts against changes in the shape.
  • the permeable layers 3, 3a-b may be attached to the frame in such a way, that the layers are pretensioned along at least one axis.
  • the permeable layers 3, 3a- b are attached to the frame in such a way, that the layers are pretensioned along at least two axes, typically arranged orthogonally to each other.
  • Fig. 1 shows a filter seen from the front without a pretensioned net
  • Fig. 2 shows the filter seen from the side without the pretensioned net
  • Fig. 3 shows a first embodiment of a filter with a pretensioned net seen from the front
  • Fig. 4 shows the first embodiment of the filter with a pretensioned net seen from the side
  • Fig. 5 shows a second embodiment of a filter with a pretensioned net seen from the side
  • the invention relates to a filter that may be used for filtration of gases or liquids, but the application in mind in the description is intended for filtration of air.
  • the filters consist of a filter cassette that in its interior contain a filter substance, typically constituted by active coal, but it may alternatively for example be constituted by salt or zeolites in granulate form of filter matter in a cloth or felt like form such as a HEPA-filter.
  • filter substances in granulate form may sink together and change volume under the influence of shaking, so it is important that the filter substance is kept in place such that it doesn't sink together and leaves voids where the air may pass unfiltered.
  • Fig. 1 shows a filter 4a seen from the front without a pretensioned net.
  • the filter comprises a filter cassette with a set of seven horizontal cross bars 1 and two side bars 2a-b, which jointly forms a frame with a set of filter cells.
  • a net 3a-b is arranged, and the net in conjunction with the frame forms six closed filter cells filled with a filter substance.
  • the filter is typically arranged upright, such that what in the image plane is upwards, in use constitutes the vertical axis.
  • Fig. 2 shows the filter 4a seen from the side without the pretensioned net 3a-b seen from the side, and it illustrates how the weight of the filter substance makes the net bulge outwards.
  • the bulging is highly exaggerated in order to illustrate the principle, but in reality some such bulging of the net takes place.
  • the figure illustrates how the net bulges outwards as a result of the weight of the filter substance itself, but the net may also often have internal stresses that makes it spontaneously form randomly distributed bulges, which in a corresponding fashion leave an opportunity for the filter substance to be redistributed and leave portions of the cells void of filter substance.
  • Fig. 3 shows a first embodiment of a filter 4a with a pretensioned net seen from the front
  • an here arrows illustrate the pretensioning of the net intending to force it to attain a shape that is as flat as possible and remain in that shape.
  • the arrows are directed from the upper and lower edges of the filter, and from its sides, where all the arrows are directed at an orthogonal angle to the upper and lower edges of the filter, and from its sides, respectively.
  • the arrows indicate the direction of the force with which the pretensioning of the net is set.
  • the net is thus tensioned such that it gets pretensioned in the way the arrows indicate, and it is the fastened onto the frame in a pretensioned state.
  • the net is fastened at a large number of points on the frame and it may alternatively be glued onto the frame such that it is attached to all the upper and lower surfaces that are exposed upwards and downwards, respectively, that is towards and away from the viewer of the figurer. In this way, the net remains tensioned across all the cells and is forced onto a nearly fully plane state. If exposed to a load, the pretensioning will in addition act to counteract the load and prevent the net from bulging out to the extent it would have without pretensioning.
  • the pretensioning may be achieved with a pretensioning setup comprising a set of moveable attachment elements that resiliently tension the net in the directions that the arrows show, and the net remains being tensioned by the
  • Fig. 4 shows the first embodiment of the filter 4a with a pretensioned net 3a-b seen from the side.
  • the figure illustrates how the net bulges out even here, but significantly less than how much it bulges out in the non pretensioned version in fig. 2.
  • the bulging illustrated in the figure is a severe exaggeration that is just intended to illustrate the principle.
  • Fig. 5 shows a second embodiment of a filter 4 with a pretensioned net 3 seen at in a view slightly angled from the side towards the upper side.
  • the filter is here not embodied as a rectangular parallelepiped as in the first embodiment, but is embodied as a cylindrical element.
  • the element has a comparatively thin wall with a thickness roughly comparable to that of the first embodiment, and this wall contains the filter substance. Air is forced through this wall into the interior of the cylinder and air is drawn from the interior of the cylinder or is alternatively pushed into the interior of the cylinder.
  • the cylinder is normally provided with a lid at either opening, and is attached to a pump or a fan at the opposite opening, but neither is illustrated.
  • the arrows only extend upwards from the cylinder top and downwards from the cylinder bottom.
  • the pretensioning is present only in a direction parallel to the centre axis of the cylinder. Had pretensioning existed along the circumference of the cylinder, it would have acted to force the net towards the cylinder centre axis, which may be acceptable under certain circumstances.
  • the selected pretensioning along only one axis forces the net to form a so nearly cylindrical shape as possible, and if exposed to a load, the pretensioning acts to counteract this load.
  • a pretensioning setup comprising a set of moveable attachment elements, that resiliently tensions the net upwards and downwards, such that the net remains tensioned by the pretensioning setup until the net is finally fastened to the cylindrical frame.
  • the filter cassettes are described as a set of bars, but clearly the filter cassettes may be embodied in many other ways that achieves essentially the same shape. Filters may obviously also be embodied in many other ways than as cylindrical tubes or as thin rectangular parallelepipeds, but these two embodiments are common.
  • the pretensioning must be adapted in a corresponding fashion. The two examples show pretensioning along one direction and along directions being orthogonal to each other, respectively. Obviously, the pretensioning may be arranged in many other ways, as long as pretensioning of some kind is present.
  • the elements that here are denoted nets are often nets made from plastic or metal wires, but it can obviously be replaced with many different types of permeable cloth like, net like or ply like elements

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Filtering Of Dispersed Particles In Gases (AREA)
  • Filtering Materials (AREA)

Abstract

The invention relates to a filter (4a-b) with cells delimited by a frame element (1, 2a-b) and two permeable layers (3, 3a-b). The cells contain a filter substance. The permeable layers (3, 3a-b) are attached to the frame in such a way, that the layers are pretensioned, which makes the permeable layers tend towards a well defined shape, and if the layers are exposed to a load, the pretensioning acts against changes in the shape. The permeable layers (3, 3a-b) may be attached to the frame in such a way, that the layers are pretensioned along at least one axis. In one embodiment, the permeable layers (3, 3a-b) are attached to the frame in such a way, that the layers are pretensioned along at least two axes, typically arranged orthogonally to each other.

Description

Deformation resistant filter
The present invention relates to a deformation resistant filter according to the introductory portion of the independent claim.
Background of the invention
Filters typically consist of a frame like arrangement enclosed on two sides by a net, where a filtering substance is held in the closed space formed by the frame and the net. The substance is often in granulate form, which may set if exposed to shaking and loads. If the net gives way to the load, voids that lacks filter substance may form in the interior of the filter, and the fluid that should have been filtered by the substance may then pass through the filter unfiltered.
An object of the invention is therefore to provide a deformation resistant filter which minimizes the risk that voids that lacks filter substance form in the filter.
These and other objects are attained by a deformation resistant filter according to the
characterising portion of the independent claim.
Summary of the invention
The invention relates to a filter 4a-b comprising at least one cell delimited by a frame element 1, 2a-b and two permeable layers 3, 3a-b. The at least one cell contains a filter substance. The permeable layers 3, 3a-b are attached to the frame in such a way, that the layers are pretensioned, which has the advantage that the permeable layers tend towards a well defined shape, and if the layers are exposed to a load, the pretensioning acts against changes in the shape.
The permeable layers 3, 3a-b may be attached to the frame in such a way, that the layers are pretensioned along at least one axis. In an advantageous embodiment, the permeable layers 3, 3a- b are attached to the frame in such a way, that the layers are pretensioned along at least two axes, typically arranged orthogonally to each other. Brief description of the drawings
Fig. 1 shows a filter seen from the front without a pretensioned net
Fig. 2 shows the filter seen from the side without the pretensioned net
Fig. 3 shows a first embodiment of a filter with a pretensioned net seen from the front
Fig. 4 shows the first embodiment of the filter with a pretensioned net seen from the side
Fig. 5 shows a second embodiment of a filter with a pretensioned net seen from the side
Description of preferred embodiments
The invention relates to a filter that may be used for filtration of gases or liquids, but the application in mind in the description is intended for filtration of air. The filters consist of a filter cassette that in its interior contain a filter substance, typically constituted by active coal, but it may alternatively for example be constituted by salt or zeolites in granulate form of filter matter in a cloth or felt like form such as a HEPA-filter. In particular filter substances in granulate form may sink together and change volume under the influence of shaking, so it is important that the filter substance is kept in place such that it doesn't sink together and leaves voids where the air may pass unfiltered.
Fig. 1 shows a filter 4a seen from the front without a pretensioned net. The filter comprises a filter cassette with a set of seven horizontal cross bars 1 and two side bars 2a-b, which jointly forms a frame with a set of filter cells. On the front and rear sides of the frame, a net 3a-b is arranged, and the net in conjunction with the frame forms six closed filter cells filled with a filter substance. In use, the filter is typically arranged upright, such that what in the image plane is upwards, in use constitutes the vertical axis.
Fig. 2 shows the filter 4a seen from the side without the pretensioned net 3a-b seen from the side, and it illustrates how the weight of the filter substance makes the net bulge outwards. The bulging is highly exaggerated in order to illustrate the principle, but in reality some such bulging of the net takes place. This gives the filter substance an opportunity to sink downwards and some distance outwards from the centre plane of the filter, such that in a worst case a void is formed at the upper portion of each cell. In this way, part of the air that passes through the filter may flow through such a void and pass through the filter unfiltered. The figure illustrates how the net bulges outwards as a result of the weight of the filter substance itself, but the net may also often have internal stresses that makes it spontaneously form randomly distributed bulges, which in a corresponding fashion leave an opportunity for the filter substance to be redistributed and leave portions of the cells void of filter substance.
Fig. 3 shows a first embodiment of a filter 4a with a pretensioned net seen from the front, an here arrows illustrate the pretensioning of the net intending to force it to attain a shape that is as flat as possible and remain in that shape. The arrows are directed from the upper and lower edges of the filter, and from its sides, where all the arrows are directed at an orthogonal angle to the upper and lower edges of the filter, and from its sides, respectively. The arrows indicate the direction of the force with which the pretensioning of the net is set.
During production, the net is thus tensioned such that it gets pretensioned in the way the arrows indicate, and it is the fastened onto the frame in a pretensioned state. The net is fastened at a large number of points on the frame and it may alternatively be glued onto the frame such that it is attached to all the upper and lower surfaces that are exposed upwards and downwards, respectively, that is towards and away from the viewer of the figurer. In this way, the net remains tensioned across all the cells and is forced onto a nearly fully plane state. If exposed to a load, the pretensioning will in addition act to counteract the load and prevent the net from bulging out to the extent it would have without pretensioning. The pretensioning may be achieved with a pretensioning setup comprising a set of moveable attachment elements that resiliently tension the net in the directions that the arrows show, and the net remains being tensioned by the
pretensioning setup until the net is finally fastened onto the frame.
Fig. 4 shows the first embodiment of the filter 4a with a pretensioned net 3a-b seen from the side. The figure illustrates how the net bulges out even here, but significantly less than how much it bulges out in the non pretensioned version in fig. 2. To completely avoid any degree of bulging is of course not possible, but with pretensioning the degree of bulging decreases significantly, and the bulging illustrated in the figure is a severe exaggeration that is just intended to illustrate the principle.
Fig. 5 shows a second embodiment of a filter 4 with a pretensioned net 3 seen at in a view slightly angled from the side towards the upper side. The filter is here not embodied as a rectangular parallelepiped as in the first embodiment, but is embodied as a cylindrical element. The element has a comparatively thin wall with a thickness roughly comparable to that of the first embodiment, and this wall contains the filter substance. Air is forced through this wall into the interior of the cylinder and air is drawn from the interior of the cylinder or is alternatively pushed into the interior of the cylinder. The cylinder is normally provided with a lid at either opening, and is attached to a pump or a fan at the opposite opening, but neither is illustrated.
The figure illustrates the pretensioning with arrows in the same fashion as in the first
embodiment, but the arrows only extend upwards from the cylinder top and downwards from the cylinder bottom. In this embodiment, the pretensioning is present only in a direction parallel to the centre axis of the cylinder. Had pretensioning existed along the circumference of the cylinder, it would have acted to force the net towards the cylinder centre axis, which may be acceptable under certain circumstances. The selected pretensioning along only one axis, forces the net to form a so nearly cylindrical shape as possible, and if exposed to a load, the pretensioning acts to counteract this load.
Here too, it is of course suitable to use a pretensioning setup comprising a set of moveable attachment elements, that resiliently tensions the net upwards and downwards, such that the net remains tensioned by the pretensioning setup until the net is finally fastened to the cylindrical frame.
In both embodiments shown, the filter cassettes are described as a set of bars, but clearly the filter cassettes may be embodied in many other ways that achieves essentially the same shape. Filters may obviously also be embodied in many other ways than as cylindrical tubes or as thin rectangular parallelepipeds, but these two embodiments are common. Depending on how the filter cassettes are designed and which shape the filters are intended to have, the pretensioning must be adapted in a corresponding fashion. The two examples show pretensioning along one direction and along directions being orthogonal to each other, respectively. Obviously, the pretensioning may be arranged in many other ways, as long as pretensioning of some kind is present. The elements that here are denoted nets, are often nets made from plastic or metal wires, but it can obviously be replaced with many different types of permeable cloth like, net like or ply like elements

Claims

3
WO 2017/105311 PCT/SE2016/000068
Claims
1 A filter (4a-b) comprising at least one cell delimited by a frame element (1, 2a-b) and two
permeable layers (3, 3a-b), where the at least one cell contains a filter substance,
characterised in that the permeable layers (3, 3a-b) are attached to the frame in such a way, that the layers are pretensioned.
2 A filter (4a-b) according to claim 1 , characterised in that the permeable layers (3, 3a-b) are attached to the frame in such a way, that the layers are pretensioned along at least one axis.
3 A filter (4a-b) according to claims 1 or 2, characterised in that the permeable layers (3, 3a-b) are attached to the frame in such a way, that the layers are pretensioned along at least two axes.
4 A filter (4a-b) according to claim 3, characterised in that the permeable layers (3, 3a-b) are attached to the frame in such a way, that the layers are pretensioned along at least two axes, where the axes are arranged orthogonally to each other.
PCT/SE2016/000068 2015-12-15 2016-11-15 Deformation resistant filter WO2017105311A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2018527732A JP2018537278A (en) 2015-12-15 2016-11-15 Anti-deformation filter
EP16876138.5A EP3389824A4 (en) 2015-12-15 2016-11-15 Deformation resistant filter

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE1500511A SE541212C2 (en) 2015-12-15 2015-12-15 Shape-stable filter with prestressed permeable layers
SESE1500511-9 2015-12-15

Publications (1)

Publication Number Publication Date
WO2017105311A1 true WO2017105311A1 (en) 2017-06-22

Family

ID=59057406

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE2016/000068 WO2017105311A1 (en) 2015-12-15 2016-11-15 Deformation resistant filter

Country Status (4)

Country Link
EP (1) EP3389824A4 (en)
JP (1) JP2018537278A (en)
SE (1) SE541212C2 (en)
WO (1) WO2017105311A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE1700284A1 (en) * 2017-11-22 2019-05-23 Qleanair Scandinavia Ab Filter magazine with membrane

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3136617A (en) * 1960-12-05 1964-06-09 Drager Otto H Air filter container
US3853519A (en) * 1972-10-03 1974-12-10 American Air Filter Co Gas filter
US4543112A (en) * 1984-04-30 1985-09-24 Figgie International Inc. Sorbent type filter assembly for a respirator and method of making same

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE314377C (en) *
DE3514038A1 (en) * 1985-04-18 1986-10-23 Hölter, Heinz, Dipl.-Ing., 4390 Gladbeck Elastic packed bed filters for vehicles
JP2013034961A (en) * 2011-08-09 2013-02-21 Hitachi Appliances Inc Air cleaner

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3136617A (en) * 1960-12-05 1964-06-09 Drager Otto H Air filter container
US3853519A (en) * 1972-10-03 1974-12-10 American Air Filter Co Gas filter
US4543112A (en) * 1984-04-30 1985-09-24 Figgie International Inc. Sorbent type filter assembly for a respirator and method of making same

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3389824A4 *

Also Published As

Publication number Publication date
SE1500511A1 (en) 2017-06-16
EP3389824A1 (en) 2018-10-24
JP2018537278A (en) 2018-12-20
EP3389824A4 (en) 2019-07-24
SE541212C2 (en) 2019-04-30

Similar Documents

Publication Publication Date Title
US8197570B2 (en) Canister air filter and method for fabricating the same
US5553648A (en) Portable wall system
KR101431887B1 (en) Filter cassette, filter arrangement, and gas turbine with such filter cassette
US8763814B2 (en) Sifting screen
CN102413897A (en) Filter assembly for gas turbine with mounting flange extension
US7563301B2 (en) Air filter with partial-depth, open-cell stabilizer to reduce detrimental shifting and settling of granular filter materials within the filter
EP3129118B1 (en) Filtration device
WO2017105311A1 (en) Deformation resistant filter
US20140291242A1 (en) Membrane module for organophilic pervaporation
US20160354712A1 (en) High pressure resistant filter
CA2847251A1 (en) A filter segment with a light weight frame
AU2011227813A1 (en) Support carrier
DE202015102184U1 (en) Plastic spring element
JP2019502538A (en) Filter cassette
RU2651852C2 (en) Screen frame
CN109225848A (en) A kind of shape anti-blocked sieving board
CN210078996U (en) Vibrating screen device
KR101520543B1 (en) Air filter with reinforcing band
WO2021193930A1 (en) Hollow fiber membrane module
CN214077732U (en) Vibrating screen for shaking-dispersing type bundling machine
KR200479380Y1 (en) Magnetic filter for organic solid fuel
CN109277279A (en) A kind of sieve plate
JPH09141008A (en) Floating type filter medium
CN109248857A (en) A kind of sieve plate easy to repair
DE8005625U1 (en) SPEAKER BOX, ESPECIALLY FOR THE LOW-TONE RANGE

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16876138

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2018527732

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE