EP0521584A1 - Sound-damping ventilating device - Google Patents
Sound-damping ventilating device Download PDFInfo
- Publication number
- EP0521584A1 EP0521584A1 EP92202034A EP92202034A EP0521584A1 EP 0521584 A1 EP0521584 A1 EP 0521584A1 EP 92202034 A EP92202034 A EP 92202034A EP 92202034 A EP92202034 A EP 92202034A EP 0521584 A1 EP0521584 A1 EP 0521584A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- sound
- shape
- channel
- plate
- shaped
- 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.)
- Granted
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
- F24F13/24—Means for preventing or suppressing noise
-
- E—FIXED CONSTRUCTIONS
- E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
- E06B—FIXED OR MOVABLE CLOSURES FOR OPENINGS IN BUILDINGS, VEHICLES, FENCES OR LIKE ENCLOSURES IN GENERAL, e.g. DOORS, WINDOWS, BLINDS, GATES
- E06B7/00—Special arrangements or measures in connection with doors or windows
- E06B7/02—Special arrangements or measures in connection with doors or windows for providing ventilation, e.g. through double windows; Arrangement of ventilation roses
Definitions
- This invention relates to a sound-damping ventilating device comprising a block-shaped housing, substantially elongated in the direction of its width, having an air inlet and an air outlet extending substantially throughout the entire width of the housing and being mutually connected within the housing via a channel having at least one of its walls partly formed by sound-damping material accommodated in a substantially U-shaped metal casing, the free ends of the legs of the U-shape being bent towards each other and these bent ends also being part of the channel wall, while the channel, over at least a part of its length between the inlet and the outlet, is divided into at least two parts by at least one element arranged in the channel.
- Such a sound-damping ventilating device is disclosed in non-prepublished Netherlands patent application 89.03189.
- the element that divides the channel into two parts is a layer of sound-damping material having its longitudinal edges encased in two metal U-sections.
- the object of the present invention is to improve a sound-damping ventilating device of the type described in the opening paragraph hereof, in such a manner that the impedance of the channel is favourably influenced to a still further degree, i.e., the sound-damping action is still further enhanced.
- the element is a plate-shaped member made from an acoustically hard material, such as a metal, which plate-shaped member is disposed above the open part of the U-shape.
- the plate-shaped member overlaps the free edges of the bent ends of the U-shape.
- the plate-shaped member has a double effect when, in accordance with a further embodiment of the invention, both channel walls are each partly formed by sound-damping material accommodated in a substantially U-shaped metal casing, the free ends of the legs of the U-shape being bent towards each other and these bent ends also being part of the channel wall, while the open parts of the U-shape are directed towards each other and the plate-shaped member overlaps the free edges of the bent ends of the two U-shapes.
- An extension of the channel resulting in further improved sound-damping, can be obtained when, in accordance with a further embodiment of the invention, viewed in cross-section, one U-shape projects relative to the other U-shape, while on the projecting side the leg of the projecting U-shape is extended to a point in front of the other U-shape, so that an L-shaped channel is obtained which, at least over a part of its length, is divided into two parts by a correspondingly L-shaped plate-shaped member. At the same time, this provides in a simple manner an effective shield preventing rain from entering the device.
- a particular predominant frequency can be so disturbing as to make additional provisions necessary.
- Helmholtz resonator it is known per se to use a Helmholtz resonator for such a purpose, but in this case, too, using the teaching of the present invention, the action of that Helmholtz resonator is improved by arranging for the plate of acoustically hard material to extend beyond the opening of the Helmholtz resonator.
- Helmholtz resonators can also be arranged at other points within the ventilating device. As long as the opening of such a resonator is covered, at a short distance therefrom, by the plate, the improved sound-damping action according to the invention is obtained.
- the sound-damping ventilating device shown in Fig. 1 comprises an elongated, tubular housing 1 having an air inlet 2 and an air outlet 3.
- the air inlet 2 can be shut off by means of a schematically shown valve 4, which can be controlled for instance by means of a knob 5.
- the valve 4 can be of a generally used type, for instance a slide comprising an outer plate provided with a plurality of ventilating apertures and, cooperating therewith, an inner plate having similar ventilating apertures, the arrangement being such that the plates can be positioned relative to each other by means of the control knob 5, in such a manner that in a first extreme, open position, the ventilating apertures in the inner plate align with the ventilating apertures in the outer plate and in a second extreme, closed position, the ventilating apertures in the outer plate are entirely covered by inner plate portions located between the ventilating apertures of the inner plate.
- any position intermediate the entirely open and the entirely closed position can be obtained by a corresponding mutual adjustment of the two plates.
- a second pair of plates likewise provided with ventilating apertures and spaced from the first pair of plates, can be controlled simultaneously by means of the control knob 5, so that a valve with an effective double seal can be obtained.
- the housing 1 comprises a top wall 6, a bottom wall 7 and two end walls 8. Between these end walls, two section parts extend in downward direction from the top wall 6. A section part 9, which is J-shaped in cross-section, extends adjacent the air inlet 2 and an L-shaped section part 10 extends adjacent the air outlet 3. Together with the top wall, section parts 9 and 10 form a U-shaped casing for a block 11 made from sound-damping material. Two section parts extend upwards from the bottom wall 7. Adjacent the air inlet 2 extends a section part 12 which is J-shaped in cross-section and adjacent the air outlet 3 extends an L-shaped section part 13.
- Section parts 12 and 13 extend from one end wall 8 to the other end wall 8 and, together with the bottom wall, form a U-shaped casing for a block 14 made from sound-damping material.
- the free ends of the section parts 9 and 10 are in line and extend parallel to the section parts 12 and 13 which in turn are in line with each other.
- the plate 16 is longer than the portion of the channel wall formed by block 11 or block 14 and extends beyond the two ends of those channel wall portions.
- the plate 16 can further be retained in position by local supports (not shown) which are connected for instance to the section parts 9, 10, 12 and 13.
- the U-shaped casing 10, 6, 9 of block 11 and the U-shaped casing 13, 7, 12 of block 14 each form a resonator body.
- Plate 16 provides that the sound waves are reflected into the resonators as fast as possible and, upon their leaving the resonators, are reflected back into the resonator again as much and as fast as possible.
- the action of the sound-damping means provided is rendered considerably more effective.
- Fig. 2 shows a ventilating device 20 accommodating an upper block 21 made from sound-damping material surrounded by a casing 22 which is open in downward direction, and a lower block 23 made from sound-damping material surrounded by a casing 24 which is open in upward direction. Between the two blocks 21 and 23 extends a channel 26 from an inlet 25 to an outlet 27. Arranged adjacent the inlet 25 is a shut-off valve 4 fitted with a control knob 5 of the type discussed with reference to the embodiment shown in Fig. 1.
- the channel between the two blocks has been extended by arranging for the upper block 21 to project relative to the lower block 23 and by extending the front wall of the casing 22 in downward direction, so that an L-shaped channel is obtained, which is divided into two parts by means of a correspondingly L-shaped plate 28 made from an acoustically hard material, such as a metal.
- block 11 and hence the casing thereof has different cross-sectional dimensions than block 14 and hence the casing thereof.
- the two casings are tuned to damping mutually different frequencies, for instance, in particular low frequencies in the spectrum of frequencies to be damped.
- sound-damping material By filling up the casings with sound-damping material, on the one hand an effective damping of high-frequent sound is obtained, while, on the other, this results in a broadening of the range which the resonator is tuned to, although this entails a leveling down of the damping efficiency of the design frequency.
- a ventilating device 30 according to Fig. 3 can be opted for.
- similar parts to those in Fig. 2 are indicated by the same reference numerals.
- a part of the block 23 shown in Fig. 2 has been replaced with a Helmholtz resonator 31 which is tuned to the frequency referred to.
- the Helmholtz resonator 31 has an access opening or slot 32 which, at a short distance therefrom, is covered by the plate 28, so that the damping action of this resonator is improved.
- the same resonator can also be used in the embodiment according to Fig. 1.
- the access slot may be situated as indicated by broken lines 32a in Fig. 3.
- swiveling valves may be provided at the outlet or outlets, and such swiveling valves can also be used in combination with a slide 4, so that the inlet and outlet can be shut off. In principle, it is also possible not to use any shut-off means at all.
Abstract
Description
- This invention relates to a sound-damping ventilating device comprising a block-shaped housing, substantially elongated in the direction of its width, having an air inlet and an air outlet extending substantially throughout the entire width of the housing and being mutually connected within the housing via a channel having at least one of its walls partly formed by sound-damping material accommodated in a substantially U-shaped metal casing, the free ends of the legs of the U-shape being bent towards each other and these bent ends also being part of the channel wall, while the channel, over at least a part of its length between the inlet and the outlet, is divided into at least two parts by at least one element arranged in the channel.
- Such a sound-damping ventilating device is disclosed in non-prepublished Netherlands patent application 89.03189. The element that divides the channel into two parts is a layer of sound-damping material having its longitudinal edges encased in two metal U-sections. By dividing the channel, while maintaining an equal rate of air flow, improved sound-damping is obtained, inter alia as a result of the additional amount of sound-damping material accommodated in the element arranged in the channel.
- The object of the present invention is to improve a sound-damping ventilating device of the type described in the opening paragraph hereof, in such a manner that the impedance of the channel is favourably influenced to a still further degree, i.e., the sound-damping action is still further enhanced.
- This is accomplished in accordance with the invention in that the element is a plate-shaped member made from an acoustically hard material, such as a metal, which plate-shaped member is disposed above the open part of the U-shape. Through these features, a considerable improvement of the sound-damping properties of the ventilating device is obtained, along with a decrease of the outside dimensions of the ventilating device inasmuch as a body has been replaced with a plate made from an acoustically hard material. This achievement is realized by making use of the fact that the U-shaped casing of the sound-damping material is in fact a resonator and the element made from acoustically hard material immediately reflects the sound waves coming from the resonator, so that the efficiency of the resonator is increased. Sounds of low frequencies in particular can thus be damped considerably more effectively.
- In order to maximize the reflective action, it is preferred, in accordance with a further embodiment of the invention, that the plate-shaped member overlaps the free edges of the bent ends of the U-shape.
- The plate-shaped member has a double effect when, in accordance with a further embodiment of the invention, both channel walls are each partly formed by sound-damping material accommodated in a substantially U-shaped metal casing, the free ends of the legs of the U-shape being bent towards each other and these bent ends also being part of the channel wall, while the open parts of the U-shape are directed towards each other and the plate-shaped member overlaps the free edges of the bent ends of the two U-shapes.
- An extension of the channel, resulting in further improved sound-damping, can be obtained when, in accordance with a further embodiment of the invention, viewed in cross-section, one U-shape projects relative to the other U-shape, while on the projecting side the leg of the projecting U-shape is extended to a point in front of the other U-shape, so that an L-shaped channel is obtained which, at least over a part of its length, is divided into two parts by a correspondingly L-shaped plate-shaped member. At the same time, this provides in a simple manner an effective shield preventing rain from entering the device.
- In certain conditions, within a sound spectrum to be damped, a particular predominant frequency can be so disturbing as to make additional provisions necessary. In that case, it is possible, and in accordance with a further embodiment of the invention, to arrange a Helmholtz resonator below the recessed U-shape, while the extended leg of the projecting U-shape and the L-shaped plate-shaped member extend to a point in front of the resonator opening, for instance formed as a stub or a slot. It is known per se to use a Helmholtz resonator for such a purpose, but in this case, too, using the teaching of the present invention, the action of that Helmholtz resonator is improved by arranging for the plate of acoustically hard material to extend beyond the opening of the Helmholtz resonator. Naturally, Helmholtz resonators can also be arranged at other points within the ventilating device. As long as the opening of such a resonator is covered, at a short distance therefrom, by the plate, the improved sound-damping action according to the invention is obtained.
- With reference to the embodiments schematically shown in the drawings, the sound-damping ventilating device according to the invention will now be further discussed and explained. In these drawings:
- Fig. 1 is a cross-sectional view of a first embodiment;
- Fig. 2 is a cross-sectional view of a second embodiment; and
- Fig. 3 is a cross-sectional view of a third embodiment.
- The sound-damping ventilating device shown in Fig. 1 comprises an elongated,
tubular housing 1 having an air inlet 2 and anair outlet 3. - The air inlet 2 can be shut off by means of a schematically shown
valve 4, which can be controlled for instance by means of aknob 5. Thevalve 4 can be of a generally used type, for instance a slide comprising an outer plate provided with a plurality of ventilating apertures and, cooperating therewith, an inner plate having similar ventilating apertures, the arrangement being such that the plates can be positioned relative to each other by means of thecontrol knob 5, in such a manner that in a first extreme, open position, the ventilating apertures in the inner plate align with the ventilating apertures in the outer plate and in a second extreme, closed position, the ventilating apertures in the outer plate are entirely covered by inner plate portions located between the ventilating apertures of the inner plate. Further, by means of thecontrol knob 5 any position intermediate the entirely open and the entirely closed position can be obtained by a corresponding mutual adjustment of the two plates. Optionally, a second pair of plates, likewise provided with ventilating apertures and spaced from the first pair of plates, can be controlled simultaneously by means of thecontrol knob 5, so that a valve with an effective double seal can be obtained. - The
housing 1 comprises atop wall 6, abottom wall 7 and twoend walls 8. Between these end walls, two section parts extend in downward direction from thetop wall 6. A section part 9, which is J-shaped in cross-section, extends adjacent the air inlet 2 and an L-shaped section part 10 extends adjacent theair outlet 3. Together with the top wall,section parts 9 and 10 form a U-shaped casing for ablock 11 made from sound-damping material. Two section parts extend upwards from thebottom wall 7. Adjacent the air inlet 2 extends asection part 12 which is J-shaped in cross-section and adjacent theair outlet 3 extends an L-shaped section part 13.Section parts end wall 8 to theother end wall 8 and, together with the bottom wall, form a U-shaped casing for ablock 14 made from sound-damping material. The free ends of thesection parts 9 and 10 are in line and extend parallel to thesection parts outlet 3. Between the free ends of thesection parts blocks - The channel 15, throughout the greater part of its length between the inlet 2 and the
outlet 3, is divided into two parts by aplate 16 made from an acoustically hard material, for instance metal. Theplate 16 is longer than the portion of the channel wall formed byblock 11 orblock 14 and extends beyond the two ends of those channel wall portions. Theplate 16, like thesection parts end wall 8 to theother end wall 8 and can be connected to theseend walls 8 to be retained in position. Theplate 16 can further be retained in position by local supports (not shown) which are connected for instance to thesection parts - The U-shaped
casing block 11 and the U-shapedcasing block 14 each form a resonator body.Plate 16 provides that the sound waves are reflected into the resonators as fast as possible and, upon their leaving the resonators, are reflected back into the resonator again as much and as fast as possible. Thus, by arranging theplate 16, the action of the sound-damping means provided is rendered considerably more effective. - Fig. 2 shows a
ventilating device 20 accommodating anupper block 21 made from sound-damping material surrounded by acasing 22 which is open in downward direction, and alower block 23 made from sound-damping material surrounded by acasing 24 which is open in upward direction. Between the twoblocks channel 26 from aninlet 25 to anoutlet 27. Arranged adjacent theinlet 25 is a shut-offvalve 4 fitted with acontrol knob 5 of the type discussed with reference to the embodiment shown in Fig. 1. Relative to this embodiment, the channel between the two blocks has been extended by arranging for theupper block 21 to project relative to thelower block 23 and by extending the front wall of thecasing 22 in downward direction, so that an L-shaped channel is obtained, which is divided into two parts by means of a correspondingly L-shaped plate 28 made from an acoustically hard material, such as a metal. - It is observed that
block 11, and hence the casing thereof, has different cross-sectional dimensions thanblock 14 and hence the casing thereof. Thus, as to their dimensions, the two casings are tuned to damping mutually different frequencies, for instance, in particular low frequencies in the spectrum of frequencies to be damped. By filling up the casings with sound-damping material, on the one hand an effective damping of high-frequent sound is obtained, while, on the other, this results in a broadening of the range which the resonator is tuned to, although this entails a leveling down of the damping efficiency of the design frequency. - If this leveling down of a particular frequency is considered undesirable, a
ventilating device 30 according to Fig. 3 can be opted for. In Fig. 3 similar parts to those in Fig. 2 are indicated by the same reference numerals. - In order to optimally damp a specific frequency, in the embodiment according to Fig. 3 a part of the
block 23 shown in Fig. 2 has been replaced with a Helmholtzresonator 31 which is tuned to the frequency referred to. The Helmholtzresonator 31 has an access opening orslot 32 which, at a short distance therefrom, is covered by theplate 28, so that the damping action of this resonator is improved. - The same resonator can also be used in the embodiment according to Fig. 1. In order to obtain the enhancing effect of the
plate 16, the access slot may be situated as indicated bybroken lines 32a in Fig. 3. - It goes without saying that the embodiments described above and shown in the figures only serve to illustrate the invention and do not limit the invention to the embodiments shown. Within the framework of the invention as defined in the appended claims, many modifications and variants are possible. For instance, it is possible to use one instead of two blocks of sound-damping material or replace a block with one or more Helmholtz resonators of which the access openings are preferably located opposite the plate at a short distance therefrom. Further, the
slide 4 can be replaced with any other suitable shut-off means, which may be arranged at any desired point in or on the housing. For instance, swiveling valves may be provided at the outlet or outlets, and such swiveling valves can also be used in combination with aslide 4, so that the inlet and outlet can be shut off. In principle, it is also possible not to use any shut-off means at all.
Claims (6)
- A sound-damping ventilating device comprising a block-shaped housing, substantially elongated in the direction of its width, having an air inlet and an air outlet extending substantially throughout the entire width of the housing and being mutually connected within the housing via a channel having at least one of its walls partly formed by sound-damping material accommodated in a substantially U-shaped metal casing, the free ends of the legs of the U-shape being bent towards each other and these bent ends also being part of the channel wall, while the channel, over at least a part of its length between the inlet and the outlet, is divided into at least two parts by at least one element arranged in the channel, characterized in that the element is a plate-shaped member made from an acoustically hard material, which plate-shaped member is disposed above the open part of the U-shape.
- A sound-damping ventilating device according to claim 1, characterized in that the plate-shaped member is made from metal.
- A sound-damping ventilating device according to claim 1 or 2, characterized in that the plate-shaped member overlaps the free edges of the bent ends of the U-shape.
- A sound-damping ventilating device according to any one of the preceding claims, characterized in that both channel walls are each partly formed by sound-damping material accommodated in a substantially U-shaped metal casing, the free ends of the legs of the U-shape being bent towards each other and these bent ends also being part of the channel wall, while the open parts of the U-shape are directed towards each other and the plate-shaped member overlaps the free edges of the bent ends of the two U-shapes.
- A sound-damping ventilating device according to claim 4, characterized in that, viewed in cross-section, one U-shape projects relative to the other U-shape, while on the projecting side the leg of the projecting U-shape is extended to a point in front of the other U-shape, whereby an L-shaped channel is obtained which, at least over a part of its length, is divided into two parts by a correspondingly L-shaped plate-shaped member.
- A sound-damping ventilating device according to claim 5, characterized in that a Helmholtz resonator is arranged below the recessed U-shape, while the extended leg of the projecting U-shape and the L-shaped plate-shaped member extend to a point in front of the opening of the resonator.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL9101182A NL9101182A (en) | 1991-07-05 | 1991-07-05 | SOUNDPROOFING VENTILATION DEVICE. |
NL9101182 | 1991-07-05 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0521584A1 true EP0521584A1 (en) | 1993-01-07 |
EP0521584B1 EP0521584B1 (en) | 1995-10-11 |
Family
ID=19859476
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19920202034 Expired - Lifetime EP0521584B1 (en) | 1991-07-05 | 1992-07-03 | Sound-damping ventilating device |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0521584B1 (en) |
DE (1) | DE69205346D1 (en) |
NL (1) | NL9101182A (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL1005260C2 (en) * | 1997-02-12 | 1998-08-13 | Zwaan Adrianus J | Forced ventilation with sound damping |
BE1013154A3 (en) * | 1999-11-25 | 2001-10-02 | Aralco Nv | Baffle |
NL1015622C2 (en) * | 2000-07-05 | 2002-05-22 | Prefair B V | Ventilation installation is for positioning in facade and comprises housing through which ventilation channel extends, being limited by lower and upper walls |
EP3120086A4 (en) * | 2014-03-20 | 2018-08-01 | VanAir Design Inc. | Panel and panel structure for ventilation and both reactive and dissipative sound dampening |
US10612239B2 (en) | 2014-03-20 | 2020-04-07 | Vanair Design Inc. | Panel and panel structure for ventilation and both reactive and dissipative sound dampening |
CN115493387A (en) * | 2022-08-12 | 2022-12-20 | 麦卡尼食品设备(中山)有限公司 | Heatable and refrigeratable dryer |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3568791A (en) * | 1968-02-27 | 1971-03-09 | Univ Sydney | Air ducting |
CH607201A5 (en) * | 1975-04-11 | 1978-11-30 | Christian Louis Grandchamps | Noise baffle for air duct |
NL8702464A (en) * | 1987-10-15 | 1989-05-01 | Zwaan Adrianus J | Ventilator installation method in window frame - uses housing in sections with one inside frame before its installation |
-
1991
- 1991-07-05 NL NL9101182A patent/NL9101182A/en not_active Application Discontinuation
-
1992
- 1992-07-03 DE DE69205346T patent/DE69205346D1/en not_active Expired - Lifetime
- 1992-07-03 EP EP19920202034 patent/EP0521584B1/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3568791A (en) * | 1968-02-27 | 1971-03-09 | Univ Sydney | Air ducting |
CH607201A5 (en) * | 1975-04-11 | 1978-11-30 | Christian Louis Grandchamps | Noise baffle for air duct |
NL8702464A (en) * | 1987-10-15 | 1989-05-01 | Zwaan Adrianus J | Ventilator installation method in window frame - uses housing in sections with one inside frame before its installation |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL1005260C2 (en) * | 1997-02-12 | 1998-08-13 | Zwaan Adrianus J | Forced ventilation with sound damping |
BE1013154A3 (en) * | 1999-11-25 | 2001-10-02 | Aralco Nv | Baffle |
NL1015622C2 (en) * | 2000-07-05 | 2002-05-22 | Prefair B V | Ventilation installation is for positioning in facade and comprises housing through which ventilation channel extends, being limited by lower and upper walls |
BE1014292A3 (en) * | 2000-07-05 | 2003-08-05 | Prefair B V | Ventilation installation is for positioning in facade and comprises housing through which ventilation channel extends, being limited by lower and upper walls |
EP3120086A4 (en) * | 2014-03-20 | 2018-08-01 | VanAir Design Inc. | Panel and panel structure for ventilation and both reactive and dissipative sound dampening |
US10612239B2 (en) | 2014-03-20 | 2020-04-07 | Vanair Design Inc. | Panel and panel structure for ventilation and both reactive and dissipative sound dampening |
CN115493387A (en) * | 2022-08-12 | 2022-12-20 | 麦卡尼食品设备(中山)有限公司 | Heatable and refrigeratable dryer |
CN115493387B (en) * | 2022-08-12 | 2023-09-22 | 麦卡尼食品设备(中山)有限公司 | Heatable and coolable dryer |
Also Published As
Publication number | Publication date |
---|---|
NL9101182A (en) | 1993-02-01 |
EP0521584B1 (en) | 1995-10-11 |
DE69205346D1 (en) | 1995-11-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0039727B1 (en) | Acoustic filter silencer | |
KR100488272B1 (en) | Ultrasonic flowmeter | |
US4109754A (en) | Noise absorber for air or gas flows | |
US8485310B2 (en) | Silencing equipment for electric devices | |
EP0521584B1 (en) | Sound-damping ventilating device | |
US3353626A (en) | Sound absorbing ventilation conduit with side branch chambers | |
DE102004007717A1 (en) | Helmholtz resonator | |
AU722512B2 (en) | An ultrasonic fluid meter with improved immunity to parasitic ultrasound waves | |
US5218872A (en) | Fluidic flowmeter for use with disturbed fluids | |
KR910021519A (en) | Silencer for Centrifugal Compressor | |
US6006858A (en) | Noise control apparatus | |
US6280153B1 (en) | Suction gas conduit for a refrigeration compressor | |
EP2484981B1 (en) | Suction apparatus | |
EP0566211B1 (en) | Sound-damping ventilating device with an elongated, block-shaped housing and a slotted ventilating channel | |
GB2271494A (en) | Variable cavity resonator | |
EP0265000B1 (en) | A silencing ventilating device, in particular for a ventilating passage in a wall or partition | |
KR101824209B1 (en) | Sound absorption apparatus using resonance for low frequency band | |
US2504915A (en) | Xylophone | |
KR102463931B1 (en) | Metamaterial muffler for noise reduction in wide bandfrequencies | |
KR20000052862A (en) | Gas meter with improved resistance to dust | |
GB2309776A (en) | Sound-damping ventilating device | |
EP0686769B1 (en) | Noise damper for hermetic compressors | |
CA2150632C (en) | Noise damper for hermetic compressors | |
EP0155924A2 (en) | Air curtaining unit | |
KR20100085537A (en) | Helmholtz resonater with porous screen |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): BE DE FR GB NL |
|
17P | Request for examination filed |
Effective date: 19930204 |
|
17Q | First examination report despatched |
Effective date: 19940916 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): BE DE FR GB NL |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Effective date: 19951011 |
|
REF | Corresponds to: |
Ref document number: 69205346 Country of ref document: DE Date of ref document: 19951116 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Effective date: 19960112 |
|
EN | Fr: translation not filed | ||
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Effective date: 19960703 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: BE Payment date: 19960812 Year of fee payment: 5 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 19960703 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19970731 |
|
BERE | Be: lapsed |
Owner name: ZWAAN ADRIANUS JACOBUS Effective date: 19970731 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: NL Payment date: 19990730 Year of fee payment: 8 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20010201 |
|
NLV4 | Nl: lapsed or anulled due to non-payment of the annual fee |
Effective date: 20010201 |