EP2068796A1 - Sound-limiting device, filter and method of manufacture - Google Patents
Sound-limiting device, filter and method of manufactureInfo
- Publication number
- EP2068796A1 EP2068796A1 EP07834534A EP07834534A EP2068796A1 EP 2068796 A1 EP2068796 A1 EP 2068796A1 EP 07834534 A EP07834534 A EP 07834534A EP 07834534 A EP07834534 A EP 07834534A EP 2068796 A1 EP2068796 A1 EP 2068796A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- filter
- sound
- limiting device
- auditory canal
- steps
- 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.)
- Withdrawn
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F11/00—Methods or devices for treatment of the ears or hearing sense; Non-electric hearing aids; Methods or devices for enabling ear patients to achieve auditory perception through physiological senses other than hearing sense; Protective devices for the ears, carried on the body or in the hand
- A61F11/06—Protective devices for the ears
- A61F11/08—Protective devices for the ears internal, e.g. earplugs
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F11/00—Methods or devices for treatment of the ears or hearing sense; Non-electric hearing aids; Methods or devices for enabling ear patients to achieve auditory perception through physiological senses other than hearing sense; Protective devices for the ears, carried on the body or in the hand
- A61F11/06—Protective devices for the ears
- A61F11/08—Protective devices for the ears internal, e.g. earplugs
- A61F11/085—Protective devices for the ears internal, e.g. earplugs including an inner channel
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/10—Sintering only
- B22F3/1017—Multiple heating or additional steps
- B22F3/1021—Removal of binder or filler
- B22F3/1025—Removal of binder or filler not by heating only
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/22—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces for producing castings from a slip
- B22F3/225—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces for producing castings from a slip by injection molding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
- B28B1/00—Producing shaped prefabricated articles from the material
- B28B1/24—Producing shaped prefabricated articles from the material by injection moulding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C33/00—Moulds or cores; Details thereof or accessories therefor
- B29C33/38—Moulds or cores; Details thereof or accessories therefor characterised by the material or the manufacturing process
- B29C33/3842—Manufacturing moulds, e.g. shaping the mould surface by machining
- B29C33/3857—Manufacturing moulds, e.g. shaping the mould surface by machining by making impressions of one or more parts of models, e.g. shaped articles and including possible subsequent assembly of the parts
Definitions
- the present invention relates to a sound-limiting device for protecting an ear against excessive noise.
- the present invention also relates to a filter for a sound-limiting device.
- the present invention further relates to a method for manufacturing a filter for a sound-limiting device.
- the present invention further relates to a method for manufacturing a sound-limiting device.
- Earplugs are generally used to protect the ear from excessive noise. High-intensity sound of short duration can result in damage to hearing, as can longer-term exposure to sound with a lower intensity.
- the known earplugs used to protect the ear have a number of operating principles. It is for instance possible to use earplugs consisting of a kneadable, solid material. It is also possible to use earplugs consisting of a foam-like material. It is further known to use earplugs consisting of a number of circular lamellas arranged in an array.
- earplugs which have a shape adapted to the auditory canal and which are provided with an open channel with a small diameter through which the sound can pass in damped form. The damping here depends partly on the diameter.
- a drawback of such existing earplugs is that the known production technologies of such filters result in relatively inaccurate production results, with the consequence of an unreliable damping factor, and therefore unintended damage to hearing.
- the present invention provides a sound-limiting device for protecting an ear against excessive noise, comprising:
- the filter comprises at least a metal component.
- the filter preferably comprises a ceramic material comprising a metal.
- a metal component is defined as a metal which is suitable to be able to form part of a ceramic material, but also as a metal per se.
- suitable ceramic materials are oxides such as zirconium oxide, silicon oxide, silicon carbide, aluminium oxide and mixtures thereof.
- Such a sound-limiting device include being able to achieve a precise sectional profile or diameter of the channel on the basis of production parameters. Greater damping factors can also be achieved in that the diameters of such a filter according to the present invention can be small. Diameters are possible here of for instance smaller than 0.3 mm, preferably smaller than 0.2 mm, more preferably smaller than 0.1 mm.
- the filter is manufactured making use of a binder, preferably an organic agent.
- a binder preferably an organic agent.
- At least one heat treatment is preferably applied in the manufacture of the filter, preferably two heat treatments.
- the first heat treatment serves for debinding and the second heat treatment preferably serves to coalesce the ceramic material, for instance by means of sintering.
- a further advantage of the heat treatments, and the sintering in particular, is that a large measure of shrinkage can be achieved here, this shrinkage being to a large extent achieved in predictable manner under the influence of process parameters to be set. Owing to this large measure of predictable shrinkage, on the one hand a diameter of the channel is achieved which is smaller than the diameter of the mould in which the channel is formed and on the other a high degree of accuracy of the desired and achieved channel diameter can be obtained with the production parameters to be selected.
- the auditory canal member extends in the position of use in an auditory canal of the ear beyond the first bend in the auditory canal, and preferably beyond the second bend in the auditory canal. This achieves that the damping through the channel is not counteracted by a leakage of sound between the auditory canal member and the wall of the auditory canal.
- the auditory canal member here preferably comprises a plastic, and more preferably a gel-like material, thereby also achieving a good material tolerance by the bodily material of the auditory canal.
- a further aspect according to the present invention relates to a filter for a sound-limiting device, comprising:
- a housing having preferably a substantially cylindrical form, - a channel extending through the housing and comprising at least one part with a sound-limiting sectional profile, wherein the housing comprises a metal component.
- a further aspect according to the present invention relates to a sound- limiting device according to the present invention, comprising a filter according to the present invention.
- a further aspect according to the present invention relates to a method for manufacturing a filter for a sound-limiting device or a filter according to claim 13, comprising steps for:
- An advantage of such a method is that a filter or a sound-limiting device according to the present invention can be obtained with great sound- damping properties and high production accuracy.
- a further aspect according to the present invention relates to a method for manufacturing a sound-limiting device comprising a filter according to the present invention, comprising steps for:
- Fig. 1 is a schematic representation of a method according to the present invention
- FIG. 2 is a schematic view of a first preferred embodiment according to the present invention of a filter
- FIG. 3 is a top view of a limiting device comprising a filter as according to Fig. 2;
- FIG. 4 is a schematic view of a first preferred embodiment according to the present invention of a filter.
- a preferred embodiment (Fig. 2) according to the present invention relates to a filter 1 for application in hearing protectors.
- a filter provides such protection in that sound waves are only allowed in damped form through the narrow channel inside filter body 2.
- the channel comprises for this purpose a narrowed portion which can be manufactured according to the present invention with great precision and great reproducibility. The chance of damage to hearing occurring due to deviations is hereby greatly reduced.
- body 2 comprises ceramic materials such as for instance aluminium oxide. Other materials or metals are also possible in alternative embodiments. A preferred embodiment of a method for manufacturing such a filter and hearing protection is described by way of example below.
- the filter of the embodiment of Fig. 1 is given a technically functional form as a substantially cylindrical tube which is truncated at the position of respective outer walls 4, 3, with a channel extending substantially around the central axis thereof.
- This channel has a form substantially similar to the form of a venturi with an elongate narrow central part in which the sound waves are damped to a significant extent. It is important here that the damping factor is readily predictable so as to enable a reliable protection.
- the channel is bounded by wall parts 5 and 6, which form respectively the narrowing and widening of the channel, and wall part 7 which forms the narrowed part.
- a method for manufacturing a filter according to the embodiment of Fig. 2 is described on the basis of the flow diagram of Fig. 1.
- the method begins in step 11 with a powdered material being provided and a binder being provided in step 12.
- the powdered material in this example is a very fine aluminium oxide powder (AIO 2 ).
- Alternative ceramic materials or precursors thereof are likewise possible.
- the binder can be chosen in suitable manner and has as its most important property that it is suitable for application as a binder in a method according to the present invention.
- the binder of the example is a so-called solvent debinder.
- step 13 these materials are then mixed to form a mixture wherein the binder is melted.
- the mixture is subsequently kneaded and further mixed.
- step 14 After the mixing of the mixing method of step 13, the mixture meanwhile obtained is formed in step 14 into small granules or globules, i.e. granulated.
- the granules are suitable for processing in an injection moulding-like process.
- this globule mixture is then brought substantially into the form of the filter in step 15, although shrinkage will occur in subsequent steps.
- step 16 a large part of the binder is then extracted from the formed material under precise control of process parameters.
- An alternative designation for the extraction is debinding.
- the workpiece is subjected for this purpose to a heat treatment at temperatures up to 500 degrees Celsius.
- the result hereof is a fragile hollow tube substantially in the form of the injection mould, albeit that the workpiece may undergo some shrinkage during this step.
- step 17 the workpiece resulting from step 16 is sintered at temperatures up to 1750 degrees Celsius while applying an accurately predetermined temperature-time curve. Further shrinkage of the workpiece occurs here as a result of compaction.
- the sintering further causes a mutual adhesion of the material of the granules, thus creating a very strong and stable tube, or the filter as described with reference to Fig. 2. Use is made here of, among other factors, internal stress in the ceramic particles. Solvent residue debinding of the material will also take place due to the sintering.
- step 18 the product is then finished by means of for instance smoothing of the outside, and the method is ended in step 19.
- an acid such as a nitric acid is preferably applied in a gas in the applied atmosphere. During the debinding step this acid will act on the organic components, such as the resins serving as binder.
- the filter in Fig. 4 differs from that of Fig. 2 in that on one side the inclining wall runs such that it leaves space for an edge 9 which extends around an end of channel 7.
- the advantage of this edge is that it can be used to support the filter thereon during one or more production stages of the filter.
- Shrinkage occurs in the workpiece during the extrusion and sintering. This shrinkage has been determined during tests as being in the order of magnitude of 20 to 30 percent. Other percentages may be possible when other process parameters are applied, and these can be determined experimentally during application of the present invention.
- An advantage of achieving this shrinkage is that a smaller diameter of the damping channel can be obtained than without such a shrinkage.
- a very predictable shrinkage factor can further be obtained with the application of suitably chosen process parameters. By applying such a method for obtaining the filters for the application, a reliable filter can surprisingly be hereby obtained for use thereof in a hearing protector according to the present invention.
- a further advantage of the shrinkage is that filter body 2 is further strengthened.
- the ceramic materials applied according to the present invention for the filter of hearing protectors have for instance been applied in the field of semiconductor technology because of the material properties of a good conductivity of electric current and good properties for generating magnetic fields.
- very small channel diameters of 0.1-0.4 mm, preferably 0.15-0.18 mm or 0.1-0.15 mm, are further possible by means of the described method and with use of these materials.
- Other possible dimensions are 0.18-0.21 mm, 0.21-0.25 mm, 0.25-0.30 mm, 0.30-0.35 mm and for instance 0.35-0.40 mm.
- Fig. 3 shows a schematic view of a hearing protector 21 or earplug according to the present invention.
- Hearing protector 21 here comprises an auditory canal part for insertion thereof into the auditory canal.
- the auditory canal can hereby be closed against sound vibrations, except substantially those which can pass through the hearing protector.
- the hearing protector further comprises a handle and/or fastening part 28 for handling and/or fastening of a cord thereto so as to prevent loss of the hearing protector.
- the auditory canal part further comprises at the substantially narrow end part thereof an opening which forms the beginning of a sound channel 25.
- This sound channel debouches on the other side thereof into a filter chamber 24, which is in turn provided with an opening 23.
- This filter chamber is suitable for permanent or semi-permanent placing of a filter 1 as known from Fig. 2 and/or which can be manufactured as according to the method of Fig. 1.
- a fixing means and/or sound-damping means can be applied between the filter and the wall of the filter chamber for the purpose of fixing the filter.
- the hearing protector It is of further importance for the hearing protector that it is per se manufactured in a manner such that it fits closely onto an individual ear and/or auditory canal of the user.
- a cast is made of the auditory canal, preferably up to a position beyond the second bend of the auditory canal.
- a body is then manufactured with the shape of the auditory canal, which body can serve as the hearing protector according to the present invention with a filter according to the present invention.
- the filter chamber for attaching the filter is formed in this body. This can be carried out during or after forming of the body.
- filters with very small channel dimensions via for instance three-dimensional print technologies.
- the filters are here constructed integrally on the basis of a predefined shape.
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL1032464 | 2006-09-08 | ||
PCT/NL2007/000218 WO2008030090A1 (en) | 2006-09-08 | 2007-09-10 | Sound-limiting device, filter and method of manufacture |
Publications (1)
Publication Number | Publication Date |
---|---|
EP2068796A1 true EP2068796A1 (en) | 2009-06-17 |
Family
ID=38925474
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP07834534A Withdrawn EP2068796A1 (en) | 2006-09-08 | 2007-09-10 | Sound-limiting device, filter and method of manufacture |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP2068796A1 (en) |
WO (1) | WO2008030090A1 (en) |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1795160A1 (en) * | 2005-12-07 | 2007-06-13 | Phonak AG | Hearing protection device with acoustic filter element and method for manufacturing the same |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2717596A (en) * | 1954-04-26 | 1955-09-13 | John S Knight | Cushion mounting for mass impedance resonance filter |
JPS6031748A (en) * | 1983-08-03 | 1985-02-18 | アサオカ株式会社 | Ear plug |
US5755234A (en) * | 1994-08-16 | 1998-05-26 | House Ear Institute | Pressure-regulating ear plug |
US7697706B2 (en) * | 2003-11-03 | 2010-04-13 | 3M Innovative Properties Company | Low sound attenuating hearing protection device |
US20060045284A1 (en) * | 2004-08-25 | 2006-03-02 | Phonak Ag | Hearing protection earplug, method for manufacturing the same and method for detecting an earplug |
-
2007
- 2007-09-10 WO PCT/NL2007/000218 patent/WO2008030090A1/en active Application Filing
- 2007-09-10 EP EP07834534A patent/EP2068796A1/en not_active Withdrawn
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1795160A1 (en) * | 2005-12-07 | 2007-06-13 | Phonak AG | Hearing protection device with acoustic filter element and method for manufacturing the same |
Also Published As
Publication number | Publication date |
---|---|
WO2008030090A1 (en) | 2008-03-13 |
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Legal Events
Date | Code | Title | Description |
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PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
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17P | Request for examination filed |
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AK | Designated contracting states |
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AX | Request for extension of the european patent |
Extension state: AL BA HR MK RS |
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DAX | Request for extension of the european patent (deleted) | ||
17Q | First examination report despatched |
Effective date: 20131113 |
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GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
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RIC1 | Information provided on ipc code assigned before grant |
Ipc: B28B 1/24 20060101ALI20180221BHEP Ipc: A61F 11/08 20060101AFI20180221BHEP Ipc: B22F 3/10 20060101ALI20180221BHEP Ipc: B29C 33/38 20060101ALI20180221BHEP Ipc: B22F 3/22 20060101ALI20180221BHEP |
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INTG | Intention to grant announced |
Effective date: 20180327 |
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GRAS | Grant fee paid |
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STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
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18D | Application deemed to be withdrawn |
Effective date: 20180807 |