EP1282895A1 - Electro-aero-acoustic source and system for active noise control - Google Patents
Electro-aero-acoustic source and system for active noise controlInfo
- Publication number
- EP1282895A1 EP1282895A1 EP01934079A EP01934079A EP1282895A1 EP 1282895 A1 EP1282895 A1 EP 1282895A1 EP 01934079 A EP01934079 A EP 01934079A EP 01934079 A EP01934079 A EP 01934079A EP 1282895 A1 EP1282895 A1 EP 1282895A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- electroaeroacoustic
- source
- flow
- obstacle
- oscillating
- 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- Withdrawn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
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K1/00—Devices in which sound is produced by striking a resonating body, e.g. bells, chimes or gongs
- G10K1/28—Bells for towers or the like
- G10K1/30—Details or accessories
- G10K1/36—Means for silencing or damping
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/20—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of a vibrating fluid
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K7/00—Sirens
Definitions
- the present invention relates to an electroaeroacoustic source, as well as an electroaeroacoustic system comprising application of such a source, this source and this electroaeroacoustic system being in particular intended for active noise control, in a confined flow.
- connection ducts of alternative machines such as compressors and heat engines, or the outputs of rotating propeller or turbine machines, such as fans and pumps, are the seat of fluctuations in flow characteristics, which cause aeroacoustic emissions them -same sources of noise pollution.
- the latter can be attenuated passively by means of so-called “silent” devices, often ineffective in low sounds, because of their necessarily limited dimensions.
- the attenuation of the noise emitted by the aforementioned fluctuations can also be carried out by now well known methods of active absorption, using loudspeakers.
- the acoustic powers required here are very large, and this results in great difficulty in implementing the loudspeakers, which must have very large dimensions.
- the loudspeakers being light mobile mechanical structures, do not have the appropriate acoustic impedance to act in a fluid pipeline, which can also be the seat of a hot or corrosive flow, for example in outlets for heat engines or refrigeration compressors.
- the present invention aims to avoid these drawbacks, by providing a particularly effective device for eliminating noise pollution, and which can advantageously replace a loudspeaker under conditions where the latter is hardly usable for the reasons mentioned above, and in particular inside ⁇ conduits where a flow circulates. ⁇
- the subject of the invention is essentially an electroaeroacoustic source, consisting of an electrodynamic or electromagnetic motor means, capable of generating an oscillatory movement, and of at least one member coupled to said motor means, so as to describe a movement oscillatory, and able to be placed in a flow or in edge of a flow, obstructing the flow, so as to exert a dynamic action on this flow.
- electroaeroacoustic source The device object of the invention, called electroaeroacoustic source, and defined above, is based on the following theoretical principle:
- the emission of an acoustic wave results, for a movable wall, from the forces exerted by the wall on the fluid, the pressure fluctuations undergone by the wall constituting, for the fluid surrounding the wall, a source of acoustic radiation.
- a flow exerts on an obstacle drag and lift forces proportional to the square of the speed.
- an acoustic source is produced associated with the temporal variation of these forces.
- the acoustic emission thus obtained has the same spectral content as the fluctuation of the preceding forces.
- the electroaeroacoustic source according to the invention comprises a member constituting an obstacle, of. suitable shape, animated by an oscillatory movement, which exerts a dynamic action on the flow in which it is placed.
- the oscillatory movement is suitably controlled by a means such as a rotary or linear electric motor, preferably oscillating, or by an organ oscillating in a magnetic induction field, preferably an oscillating coil, this means being itself controlled from 'an electrical signal, in particular in the application to the production of an active noise control system.
- the electroaeroacoustic sources produced according to the invention can have significant powers, due to the amplifying effect of the flow for the fluctuating force exerted by the fluid on the wall of the obstacle-forming member.
- these elastic return means also provide support for the obstacle-forming member, by defining an "virtual" axis of rotation.
- This arrangement is particularly advantageous in the case where the use of mechanical rotational bearings, such as ball bearings, is to be avoided; this is particularly the case when the electroaeroacoustic source must operate in a hot and / or corrosive flow, such as refrigerant compressor fluids or combustion gases.
- the electroaeroacoustic source object of the invention, has different directivity properties, depending on the aerodynamic characteristics of the obstacle-forming member, under the conditions in which this member is placed.
- the directivity of the acoustic emission from such a source is fixed by the direction of the force exerted by the member forming an obstacle on the fluid.
- a member forming an obstacle of profiled or non-profiled shape, mounted oscillating around an axis transverse to the direction of flow, and creating a wake, has a directivity mainly oriented parallel to the direction of flow, insofar as said obstacle-forming member has no lift.
- An example of an obstacle-forming member is a substantially rectangular oscillating flap, the axis of oscillation preferably passing through the center of the flap.
- electroaeroacoustic sources having a directivity mainly oriented parallel to the direction of the flow, can be designated as “axial” electroaeroacoustic sources. It is also possible to produce electroaeroacoustic sources, in accordance with the invention, which have a directivity substantially perpendicular to the direction of flow, and which can be designated as “transverse” electroaeroacoustic sources. Unlike axial sources, a transverse electroaeroacoustic source must include an obstacle-forming member which has a strong lift relative to the flow. A typical example of such a member is an oscillating flap having a wing profile.
- electroaeroacoustic sources previously defined being simple sources, it is possible to multiply them to produce a multiple electroaeroacoustic source, associating two or more similar elementary electroacoustic sources, all of axial type or of transverse type; all these sources are arranged, in the flow, "in parallel” or “in series” or according to a combination of these arrangements, and they are animated by the same oscillatory movement.
- complex electroaeroacoustic sources which make it possible to obtain varied and specific effects, resulting on the one hand from the interaction of neighboring obstacles, fixed or mobile, and d on the other hand, different values of moments of inertia and aerodynamic forces, depending on the dimensions of the obstacles.
- complex electroaeroacoustic sources can be obtained:
- the electroaeroacoustic sources, defined above, were in relation to an indefinite flow, apart from its direction, this flow being either free or confined by walls, for example the walls of a pipe.
- the confinement of the flow by walls offers the advantageous possibility of increasing the efficiency of the electroaeroacoustic sources defined above, by placing such a source (single or multiple) at a suitable nozzle, locally creating a narrowing of the cross section of the pipe, therefore of the flow, and accelerating the flow, thereby increasing the force exerted by the electroaeroacoustic source on this flow.
- Such a nozzle can be formed by a simple fixed profiled sleeve, inserted in the pipe traversed by the flow, the electroaeroacoustic source being disposed inside the sleeve, in the reduced section delimited by this sleeve.
- the nozzle or the sleeve reducing the cross section available for the flow is produced by means of movable walls, in particular articulated around an axis, associated with mechanical control means; the fixed but adjustable position, given to these walls, makes it possible to modify the section available for the passage of the flow, therefore to increase or reduce the speed of the flow at the level of the electroaeroacoustic source, which makes it possible to control at will the efficiency of said source.
- the electroaeroacoustic source located at the edge of the flow, comprises an obstacle-forming member constituted by a part of an oscillating wall confining the flow, this part of the movable wall also making a narrowing of the cross section of the flow.
- the oscillating member forming an obstacle is located at the edge of the flow, and itself produces the nozzle.
- All the electroaeroacoustic sources, previously defined, can be used for active noise control, also designated as active acoustic absorption, in particular in confined flow with the configurations (nozzles) which have just been indicated.
- the invention provides an electroaeroacoustic system for active noise control, which essentially comprises at least one electroaeroacoustic source as defined above, with an electrodynamic or electromagnetic motor means and an obstacle-forming member, placed in a flow or at the edge of a flow, as well as a controller controlling said motor means, the controller itself being controlled from at least one microphone measuring the noise to be controlled.
- the controller can be a single channel controller.
- the controller will be a multi-channel type controller.
- the electroaeroacoustic systems for active noise control can use, as active means for combating noise, only electroaeroacoustic sources as defined above, in which case they are “pure” electroaeroacoustic systems. . “Mixed” systems can also be envisaged, which use on the one hand at least one electroaeroacoustic source, as defined above, and on the other hand an active or passive means of noise attenuation operating according to a different principle.
- a mixed system can comprise on the one hand at least one electroaeroacoustic source, and on the other hand a loudspeaker; the loudspeaker makes it possible to process acute frequencies here, which electroaeroacoustic sources can hardly emit.
- the loudspeaker can be replaced by another active means, such as a controlled electro-pneumatic source.
- a passive means associated with at least one electroaeroacoustic source, and more particularly a source placed in a nozzle (as defined above), provision is advantageously made for the nozzle to be made of a sleeve made of absorbent acoustic material.
- a sleeve made of absorbent acoustic material.
- Figure 1 is a block diagram, in perspective, of an electroaeroacoustic source according to the invention
- Figure 2 is a side view of the source of Figure 1, placed in a free flow and constituting an axial source;
- Figure 3 is a view similar to Figure 2, but illustrating another arrangement of this axial source
- Figure 4 is a perspective view of an electroaeroacoustic source according to the invention, of particular conformation
- Figure 5 is a side view of the source of Figure 4.
- FIG. 6 is a perspective view of another electroaeroacoustic source according to the invention, of particular configuration
- FIG. 7 is a perspective view illustrating a particular assembly of an electroaeroacoustic source, such as that of FIG. 6.
- Figure 8 is a side view of an electroaeroacoustic source such as that of Figure 1, placed in a flow and constituting a transverse source;
- Figure 9 is a block diagram of a complex electroaeroacoustic source
- Figure 10 is a block diagram of a multiple electroaeroacoustic source
- Figure 1 1 is a block diagram of another multiple electroaeroacoustic source;
- Figures 12 and 13 illustrate examples of particular complex sources;
- Figure 14 shows, in perspective and in section, an electroaeroacoustic source placed in a confined flow
- Figure 15 is a block diagram of another source placed in a confined flow, and usable for active noise control
- Figures 16, 17, 18, 19, 20 and 21 show / in the form of block diagrams, other examples of sources used for active noise control.
- an electroaeroacoustic source generally designated by the reference 2
- an electrodynamic driving member 5 or electromagnetic such as an oscillating electric motor or an oscillating coil in a magnetic induction field, powered by an electric current, which can give the angle ⁇ of the obstacle 3 a variation of the oscillatory type.
- electromagnetic such as an oscillating electric motor or an oscillating coil in a magnetic induction field, powered by an electric current, which can give the angle ⁇ of the obstacle 3 a variation of the oscillatory type.
- FIG. 2 shows an electroaeroacoustic source 2, as described above, placed in a free flow of speed V, the obstacle 3 forming an average angle ⁇ with the direction of this flow, and thus creating a wake of transverse dimension d .
- the same obstacle 3 forms a greater mean angle ⁇ , and it creates a wake of greater transverse dimension D.
- the drag force exerted by the velocity flow V on the obstacle 3 is greater in the case of FIG. 3 than in FIG. 2, while the lift force has hardly varied, for incidences where l flow is strongly unstuck.
- the force, of an oscillatory nature, exerted by the obstacle 3 on the fluid has been indicated at F.
- the directivity of the acoustic emission of the electroaeroacoustic source 2 is fixed by the direction of this force F; this directivity being mainly oriented parallel to the direction of flow, it is here a source "axial".
- FIGS. 4 to 7 illustrating examples of sources of particular profile which meet these requirements.
- the obstacle 3 is presented as a rectangular oscillating flap 6, which carries on its leading edge a first curved wall 7, and on its trailing edge a second curved wall
- the obstacle 3 consists of a rectangular flap 9, the leading and trailing edges are bent in opposite directions, as shown in 10 and 1 1, so as to give the flap 9 a profile "S".
- the curved edges 10 and 1 1 constitute, here also, curved walls ensuring obtaining the desired wake, the latter conformation allowing, in addition, easier industrial manufacture of the obstacle 3.
- FIG. 7 illustrates a particular arrangement of the electroaeroacoustic source 2, such as that of FIG. 6 with flap 9 with an “S” profile.
- the axis 4, coincident with the axis of symmetry of the flap 9, is supported by two bearings 12, each consisting of several leaf springs 13 fixed on a fixed part 14, the leaf spring 13 serving as supports for the axis 4, therefore to the obstacle 3, and elastic return means of this obstacle 3 in its average position, with respect to which it oscillates and produces a sound emission in interaction with the flow.
- the return function of the profiled obstacle 3 in its average position can also be achieved by a simple spiral spring 1 5, this variant being illustrated in FIG. 14 (described in detail below).
- FIG. 8 shows another electroaeroacoustic source 2 which, unlike the previous ones, constitutes a “transverse” source, that is to say that its directivity is substantially perpendicular to the direction of flow, of speed V.
- the source 2 comprises an obstacle 3 with wing profile, always oscillating under the action of a motor 5, such an obstacle 3 creating on the fluid a force F mainly due to the lift.
- FIG. 9 illustrates a first example of an electroaeroacoustic source known as “complex”, which consists of an axial source 2 with obstacle 3 oscillating under the action of a motor 5, as described above, which is placed in the vicinity of a fixed obstacle 16.
- the set of obstacles, mobile 3 and fixed 16 is placed in a flow of fluid, of speed V.
- the momentary increase in the incidence of the mobile obstacle 3 causes an increase in the speed of the fluid on the fixed obstacle 16, by deflection of the flow, which has the effect of increasing the pressure on this obstacle 16, in its instantaneous aeroacoustic emission.
- the set of two obstacles 3 and 16, one oscillating and motorized and the other fixed thus constitutes an electroaeroacoustic source of specific structure and functioning, and of efficiency greater than source 2 alone, which is here a axial source.
- FIG. 10 shows an electroaeroacoustic source called "multiple”, which consists of several simple sources 2, as described above.
- multiple an electroaeroacoustic source
- each source 2 comprising an oscillating flap 6 actuated by a motor 5.
- the three sources 2 are here identical in their shapes and dimensions, and driven by the same oscillatory movement.
- the replacement of a single electroaeroacoustic source, giving a variation in wake width of given amplitude, by synchronous electroaeroacoustic sources in parallel, of dimension reduced in proportion to the number n makes it possible to obtain a torque n 3 times more small for each source and, in total, an electromechanical power n 2 times smaller.
- the sound emission from sources 2 thus grouped is reinforced by their interaction effect, which is analogous to that described above for the association of a source 2 with oscillating obstacle 3 and a fixed obstacle 16 (FIG. 9).
- FIG. 11 it is also possible to group several simple electroacoustic sources 2, 2 ′, and 2 ′′ with different characteristics, in particular of different dimensions and adapted to the pulsations and amplitudes of different frequency bands, such a complex source allowing the 'obtaining various effects, reinforced by the interaction of flows around the respective obstacles 3, 3' and 3 ".
- the lowest frequencies are for example produced with a larger source than the medium frequencies and, a fortiori, than the lowest frequencies. More particularly, FIG.
- FIG. 11 shows an embodiment of a complex electroaeroacoustic source where the lowest pulsation is emitted by the source 2 'situated in the middle, the average pulsation being mainly emitted by the lower source 2 ", while the high pulsation is produced by the upper source 2.
- FIG. 12 shows another embodiment of a complex electroaeroacoustic source, which consists of a transverse source 2 with obstacle 3 oscillating under the action of a motor 5, which is placed in the vicinity of a fixed obstacle 17 of wing profile similar to that of the mobile obstacle 3.
- the reinforcing effect of the fixed obstacle 17 is here analogous to that of the fixed obstacle 16 associated with an axial source in the example of FIG. 9.
- FIG. 13 shows yet another embodiment of a complex electroaeroacoustic source, which combines an axial source 2a and a transverse source 2b, so that the main direction of emission takes place in the oblique direction of the resultant R des non-permanent drag forces T from the axial source 2a, and lift P from the transverse source 2b.
- a complex electroaeroacoustic source which combines an axial source 2a and a transverse source 2b, so that the main direction of emission takes place in the oblique direction of the resultant R des non-permanent drag forces T from the axial source 2a, and lift P from the transverse source 2b.
- FIGS. 14 et seq Representing electroaeroacoustic sources placed in a confined flow, that is to say, in practice, in a pipe 18 traversed by a fluid, the speed of which is always indicated in V. These sources are applied to active noise control.
- FIG. 14 shows a simple electroaeroacoustic source 2, produced as described above, with an oscillating obstacle 3 placed inside the pipe 18 traversed by the flow. More particularly, the oscillating obstacle 3 of this source 2 is placed in a nozzle 19, housed and fixed in the pipe 18, which locally achieves a local reduction in the cross section of the pipe 18, and which thus accelerates the flow of the fluid and increases the force exerted by said source 2 on this flow.
- FIGS. 1 5 and following illustrate various embodiments of sources placed in confined flow, and applied to active noise control, according to the principle described above.
- FIG. 15 shows an electroaeroacoustic source 2 placed in a pipe 18, at the level of a nozzle produced by means of walls 22 each articulated around an axis 23.
- the nozzle here again reduces the cross section available for flow, and in the present case an appropriate mechanical control device (not shown) makes it possible to pivot the movable walls 22 and to modify their position, so as to adjust the section available for flow.
- an appropriate mechanical control device (not shown) makes it possible to pivot the movable walls 22 and to modify their position, so as to adjust the section available for flow.
- the efficiency of the source 2 is increased, for a given amplitude of oscillation of its flap 9. It may be advantageous to erase the movable walls 22, when it is desired not to put the electroaeroacoustic source 2 into action.
- FIG. 15 shows the active noise control system, with its single-channel controller 20, in relation to the motor 5 of the source 2, with a control microphone 21 and also with a reference microphone 24, the two microphones 21 and 24 being placed inside the pipe 18,
- FIG. 16 in which the elements corresponding to those previously described are designated by the same references, shows a multiple electroaeroacoustic source, comprising two identical simple sources 2 arranged in parallel.
- the multiple source thus formed is placed in line 18, at a nozzle 19.
- the single-channel controller 20 here supplies, synchronously, the motors 5 of the two simple sources 2.
- FIG. 17 represents an active noise control system, using a complex source resulting from two simple electroaeroacoustic sources 2a and 2b, respectively axial and transverse, arranged "in series" inside the pipe 18, at the level of the nozzle 19.
- the two sources 2a and 2b are supplied separately, by a multi-channel type controller 20 receiving the signals from two control microphones 21 a and 21 b and from two reference microphones 24a and 24b.
- the active noise control system can implement an actuator of a different principle, in particular a speaker 25.
- the electroaeroacoustic source 2 is placed in the pipe 18, at the nozzle 19.
- the loudspeaker 25 is placed on the wall of the pipe 18.
- a multi-channel controller 20 supplies the motor 5 of the source 2 separately, and the loudspeaker 25. The latter makes it possible to process high frequencies, as the source electroaeroacoustics 2 can hardly emit.
- This active noise control system can in particular be applied to ventilation devices, where the usually non-corrosive atmosphere allows speakers to be inserted. In the examples of FIGS.
- the nozzle 19 is of generally cylindrical shape and results from a fixed profiled sleeve, inserted in the pipe 18 traversed by the flow, this sleeve being full, or at least at solid wall.
- Figures 19 and 20 illustrate variants, in which the nozzle 19 is constituted by a fixed profiled sleeve, made of absorbent acoustic material 26 which can be contained in an envelope 27 with a perforated wall.
- the electroaeroacoustic source 2 which is a simple source, processes the low frequencies, while the nozzle 19 of special constitution absorbs the high frequencies.
- FIG. 19 the electroaeroacoustic source 2 which is a simple source, processes the low frequencies, while the nozzle 19 of special constitution absorbs the high frequencies.
- the low and medium frequencies are processed by the complex electroaeroacoustic source, consisting of two simple sources 2 and 2 'in parallel controlled by the single-channel controller 20, while the high frequencies are passively absorbed by the absorbent acoustic material 26 of the nozzle 19.
- the assembly thus constitutes a semi-active control system for a confined flow circuit.
- FIG. 21 shows another embodiment of the invention, in which the pipe 18 comprises a part 28 which narrows the cross section, available for flow, this part 28 being constituted by flexible walls, able to be driven by a vibratory movement by means of electromagnets 29 placed outside the pipe 18.
- the movable walls 28 here play the role of the oscillating obstacle of the previous embodiments.
- the configuration in FIG. 21 creates a pressure difference due to the existence of swirling wakes T in the sudden widening 30 of the cross section following the narrowing resulting from the shape of the movable walls 28.
- the axial acoustic effect is practically zero if the obstacle consists of a profiled obstacle for which no separation is observed.
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Mechanical Engineering (AREA)
- Apparatuses For Generation Of Mechanical Vibrations (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
- Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)
Abstract
Description
Claims
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR0006018 | 2000-05-11 | ||
FR0006018A FR2808916B1 (en) | 2000-05-11 | 2000-05-11 | ELECTROAEROACOUSTIC SOURCE AND SYSTEM FOR ACTIVE NOISE CONTROL |
PCT/FR2001/001414 WO2001086632A1 (en) | 2000-05-11 | 2001-05-10 | Electro-aero-acoustic source and system for active noise control |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1282895A1 true EP1282895A1 (en) | 2003-02-12 |
Family
ID=8850115
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP01934079A Withdrawn EP1282895A1 (en) | 2000-05-11 | 2001-05-10 | Electro-aero-acoustic source and system for active noise control |
Country Status (9)
Country | Link |
---|---|
US (1) | US20040086136A1 (en) |
EP (1) | EP1282895A1 (en) |
JP (1) | JP2004501393A (en) |
KR (1) | KR20030016258A (en) |
AU (1) | AU2001260392A1 (en) |
DE (2) | DE20122913U1 (en) |
FR (1) | FR2808916B1 (en) |
WO (1) | WO2001086632A1 (en) |
ZA (1) | ZA200209611B (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2022183927A (en) * | 2021-05-31 | 2022-12-13 | 三菱重工業株式会社 | Sound pressure generation device |
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- 2000-05-11 FR FR0006018A patent/FR2808916B1/en not_active Expired - Lifetime
-
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- 2001-05-10 JP JP2001583500A patent/JP2004501393A/en active Pending
- 2001-05-10 WO PCT/FR2001/001414 patent/WO2001086632A1/en active Application Filing
- 2001-05-10 US US10/275,507 patent/US20040086136A1/en not_active Abandoned
- 2001-05-10 EP EP01934079A patent/EP1282895A1/en not_active Withdrawn
- 2001-05-10 DE DE20122913U patent/DE20122913U1/en not_active Expired - Lifetime
- 2001-05-10 KR KR1020027015088A patent/KR20030016258A/en not_active Application Discontinuation
- 2001-05-10 DE DE01934079T patent/DE01934079T1/en active Pending
- 2001-05-10 AU AU2001260392A patent/AU2001260392A1/en not_active Abandoned
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2002
- 2002-11-26 ZA ZA200209611A patent/ZA200209611B/en unknown
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Title |
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See also references of WO0186632A1 * |
Also Published As
Publication number | Publication date |
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ZA200209611B (en) | 2003-09-30 |
DE20122913U1 (en) | 2009-10-29 |
AU2001260392A1 (en) | 2001-11-20 |
JP2004501393A (en) | 2004-01-15 |
KR20030016258A (en) | 2003-02-26 |
FR2808916B1 (en) | 2003-08-15 |
US20040086136A1 (en) | 2004-05-06 |
WO2001086632A1 (en) | 2001-11-15 |
FR2808916A1 (en) | 2001-11-16 |
DE01934079T1 (en) | 2008-04-24 |
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