[go: up one dir, main page]

EP0408221B1 - Gleichstrommotorgetriebener Zentrifugalventilator - Google Patents

Gleichstrommotorgetriebener Zentrifugalventilator Download PDF

Info

Publication number
EP0408221B1
EP0408221B1 EP19900307116 EP90307116A EP0408221B1 EP 0408221 B1 EP0408221 B1 EP 0408221B1 EP 19900307116 EP19900307116 EP 19900307116 EP 90307116 A EP90307116 A EP 90307116A EP 0408221 B1 EP0408221 B1 EP 0408221B1
Authority
EP
European Patent Office
Prior art keywords
motor
scroll
centrifugal fan
fan
impeller
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.)
Revoked
Application number
EP19900307116
Other languages
English (en)
French (fr)
Other versions
EP0408221A2 (de
EP0408221A3 (en
Inventor
Ivor William Bolton
David Sydney Gaunt
Ronald Kenneth Russell
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TORIN Ltd
International Business Machines Corp
Original Assignee
TORIN Ltd
International Business Machines Corp
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
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=10660081&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0408221(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by TORIN Ltd, International Business Machines Corp filed Critical TORIN Ltd
Publication of EP0408221A2 publication Critical patent/EP0408221A2/de
Publication of EP0408221A3 publication Critical patent/EP0408221A3/en
Application granted granted Critical
Publication of EP0408221B1 publication Critical patent/EP0408221B1/de
Anticipated expiration legal-status Critical
Revoked legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
    • F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
    • F04D29/668—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps damping or preventing mechanical vibrations
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/40—Casings; Connections of working fluid
    • F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
    • F04D29/4206—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
    • F04D29/4226—Fan casings
    • F04D29/424—Double entry casings

Definitions

  • This invention relates to d.c motor driven centrifugal fans for low noise applications according to the pre-characterizing part of claim 1.
  • Brushless d.c motors have a number of advantages when used to drive centrifugal fans in terms of safety, flexibility of performance and low power consumption as compared to a.c motors. They allow lower speed operation which reduces aerodynamic noise and they have the flexibility to match the air flow to the system cooling requirements by changing the fan speed at will.
  • brushless d.c fans suffer from three major disadvantages when used in low noise level applications; namely discrete tones generated at the blade passing frequencies, bearing noise and tones produced by motor vibrations at harmonics of the DC motor torque pulsation frequency.
  • the latter is more predominant the quieter the broad band aerodynamic noise, and can be a limiting factor in minimising installed fan noise.
  • the rotational speed of a DC fan can vary with back pressure depending on the motor design and this can cause a wide variation in noise level as the motor pulsation frequency may coincide with the motor and fan structural vibration modes.
  • the high starting current can be limited by an increase in magnetic reluctance but this results in increased motor speed with load.
  • a phenomenon of centrifugal fans is that the motor load varies inversely with changing back pressure, increasing speed and aerodynamic noise. Although such speed variations may be a disadvantage in terms of noise, significant benefits are offered to a designer who requires constant airflow at a varying system static pressure loss.
  • the motor design is therefore a compromise between conflicting requirements of cost, air flow performance and acoustics, the latter being determined by the interaction between the motor and the fan structure.
  • an a.c motor fan scroll which is cut back from the conventional fully developed form has been employed in the IBM 9335 Model BO1 disk storage unit.
  • dual impellers and scrolls are mounted to either side of a central a.c motor which is itself supported on a separate fan housing.
  • the fan scrolls were cut back in the 9335 purely so that they could be fitted into the avallable space and attached to a common plate.
  • An airstream splitting arrangement is attached to the opposite side of the plate to split and direct the emergent airstream to different parts of the disk storage unit.
  • A.c motor fans have much simpler resonance problems than d.c motor fans and these are cured relatively simply in the 9335 by resiliently mounting the motor on the fan housing to isolate the housing from mains frequency vibration.
  • the prior art has therefore falled to provide a simple way of reducing noise in a centrifugal d.c motor driven fan which is effective over a wide range of operating conditions.
  • the present invention provides a centrifugal fan comprising a brushless d.c. motor; an impeller mounted on the motor for rotation thereby; and a scroll, on which the motor is mounted, the scroll defining an air inlet and outlet and including an outer wall curved around the impeller to define a divergent path to the outlet for air driven by the impeller, characterised in that the scroll is truncated at the outlet so as to substantially eliminate any flat portions on the outer wall susceptible to mechanical vibration at frequencies excited by the d.c. motor.
  • the scroll outer wall is curved along its entire length but it has been found that a relatively short flat portion may be included at the outlet as long as it does not become excited by motor pulsation frequencies.
  • the preferred outlet shape is a substantially rectangular aperture, the plane of which is closest to the impeller along a line intermediate the circumferentially spaced edges of the aperture. This may be thought of as an angled cutback (typically 45°) as compared to the included angle of 90° in a normal fully developed scroll. Clearly, other angles may be used and the outlet shape need not be rectangular.
  • the rectangular shape does facilitate attachment of the fan by its scroll to a mounting plate by means of coplanar outwardly extending flanges and is thus preferred.
  • the scroll includes two side walls each of which is apertured to provide an air inlet. This allows a lower fan inlet air velocity for a given volume of air thus reducing aerodynamic noise.
  • the motor should additionally be resiliently mounted on the scroll. This can reduce the other resonances not affected by the outlet shape.
  • resilient mounting may be chosen but the preferred one includes a motor support frame resiliently supported from a side wall of the scroll and extending axially into the scroll, within the impeller, to support the motor.
  • This is preferably implemented as an outer plate, co-extensive with the side wall and a cage portion extending axially into the scroll and being rigidly connected to the motor.
  • the resilient connection is provided by circumferentially disposed vibration isolators between the outer plate and scroll side wall. If the outer plate is annular in shape, then obstruction of an air inlet in the scroll side wail can be minimised.
  • the motor support frame can be made of an elastomeric material to provide vibration isolation.
  • Figures 1 and 2 show vibrational mode models produced by computer aided design analysis for a fully developed scroll 10 and for a truncated scroll 20 according to the inventions.
  • the fan rpm increases and the motor pulsation frequency is effectively de-coupled from the scroll resonant modes until such time that the fan rpm is high enough for the next pulsation harmonic to match the scroll. Since the motor rpm increased rapidly with back pressure there were several peaks in the sound power vs back pressure curve which had to be reduced in order to meet the design requirements.
  • the motor isolation design was constrained by fan application requirements, the final choice being a grommet isolator with radial and axial resonant frequencies as low as possible. These were controlled by the motor/impeller weight and the need for dimensional stability between impeller and scroll for reasons of performance and aerodynamic noise.
  • the final grommet selected had calculated axial and radial resonant frequencies of 287 and 609 Hz respectively.
  • a d.c motor driven fan according to the invention is illustrated in Figures 7, 8 and 9.
  • a brushless d.c motor 50 of the kind described in International Patent Application, publication no WO88/07285.
  • the motor consists of a stator 51, rotor 52, and a support body 53 providing a bearing housing for the rotor shaft and integrally moulded with a printed circuit board 54 carrying the electronic components of the motor.
  • the motor is completed by a cover plate 55 (not shown in Fig 7).
  • the motor rotor is attached by means of a central annular web 56 to an impeller 60, best seen in Figure 7.
  • the impeller blades 61, 62 on each side of the central web are offset at half pitch in order to reduce tones at the blade passing frequency.
  • a scroll 70 Surrounding the impeller 60 is a scroll 70 from one side of which the motor/impeller assembly is mounted by means of mounting frame 80.
  • the scroll consists of a curved outer wall 71, surrounding the impeller, and side wall potions 72 which are apertured to provide dual air inlets to the motor.
  • the scroll defines a divergent path for air driven by the impeller to an outlet 73, which is rectangular in shape.
  • Out-turned flanges 74 surrounding the outlet enable the fan to be mounted on a mounting plate or bulkhead, for example by spot welding.
  • the shape of the outer wall 71 is key to achieving the reduction in noise from motor induced vibration.
  • the scroll 70 is truncated at an angle of approximately 45° as viewed in Figure 8. This substantially eliminates all but a small linear portion of the scroll outer wall and, with it, the flat surface prone to vibrate at frequencies excited by motor 50.
  • the scroll outer wall should consist only of a curved surface, as in the model of Figure 2, but the small linear continuation 75 of the otherwise curved surface 71 has been found not to be a source of significant acoustic radiation.
  • the cutback scroll design reduces the number of modes of vibration of the scroll below 650 Hz (those likely to be excited by motor pulsation harmonics) from five to two and the new shape exhibits little vibration along the "free" outer edge of the scroll.
  • vibration isolation of the motor/impeller assembly is needed. In the fan of Figures 7 to 9, this is achieved by attaching the motor mounting frame 80 to the scroll side wall 72 by means of three grommets 81.
  • the grommets are selected to have the necessary axial and radial resonant frequencies to isolate the scroll from the remaining motor pulsation frequencies.
  • the mounting frame 80 is moulded from a plastics material and consists of an annular outer plate 82, having location slots 83 for three grommets, and a cage portion 84 extending axially into the scroll.
  • Cage portion 84 includes four angle-sectioned ribs 85 each terminating in fingers 86 which locate in complementary cut-outs in the support body 53 and printed circuit board 54 to support the motor.
  • the final design in a duplex fan assembly running at 12 volts has a very low 'A' weighted sound power level which varies consistently with back pressure from 3.97 bels at free flow to 4.50 bels at 2mm of water at an air flow delivery of 25 litres/sec.
  • FIG 12 shows schematically an alternative motor mounting frame which may be substituted for frame 80 of Figures 7 to 9.
  • the frame 100 is moulded from a heavy rubber and comprises a base portion 101 bonded to the motor 102.
  • Three legs 103 extend from the base outwardly through an air inlet in scroll 104 and are turned through U-bends to terminate in feet 105.
  • the ankle portion 100 above each foot is necked to form an isolation mount.
  • the shape of the portion 106 determines the relative axial to radial stiffness and is determined by the motor pulsation frequency harmonies.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Motor Or Generator Frames (AREA)

Claims (13)

  1. Ein Zentrifugalventilator, einen bürstenlosen Gleichstrommotor (50) aufweisend;
    ein Laufrad (60), auf einem Motor montiert und durch diesen drehbar;
    und eine Spirale (70), auf welcher der Motor montiert ist, wobei die Spirale einen Lufteintritt und -austritt (73) definiert und eine Außenwand (71) umfaßt, die um das Laufrad gekrümmt ist, um für die durch das Laufrad zugeführte Luft einen divergierenden Weg zum Austritt zu definieren, dadurch gekennzeichnet, daß die Spirale am Austritt gekürzt ist, so daß alle flachen Teile auf der Außenwand, die für mechanische Schwingungen bei vom Gleichstrommotor erregten Frequenzen empfindlich sind, im wesentlichen wegfallen.
  2. Ein Zentrifugalventilator nach Anspruch 1, bei dem die Außenwand der Spirale auf ihrer gesamten Länge vollständig gekrümmt ist.
  3. Ein Zentrifugalventilator nach Anspruch 1 oder Anspruch 2, bei dem der Austritt eine im wesentlichen rechteckige Apertur ist, deren Ebene entlang einer Linie zwischen den am Umfang angeordneten Kanten der Apertur dem Laufrad am nächsten liegt.
  4. Ein Zentrifugalventilator nach Anspruch 3, bei dem die Spirale koplanare Flansche (74) aufweist, die von den Kanten der rechteckigen Austrittsapertur nach außen verlaufen, mit deren Hilfe der Ventilator auf einer Montageplatte montiert werden kann.
  5. Ein Zentrifugalventilator nach jedem der vorangehenden Ansprüche, bei dem die Spirale zwei Seitenwände (72) aufweist, von denen jede eine Öffnung besitzt, um den Eintritt der Luft zu ermöglichen.
  6. Ein Zentrifugalventilator nach jedem der vorangehenden Ansprüche, bei dem der Motor elastisch an der Spirale befestigt ist, um die Erregung von Resonanzen in der Spirale durch den Motor weiter zu reduzieren.
  7. Ein Zentrifugalventilator nach Anspruch 6, bei dem die Spirale eine Seitenwand aufweist und der Ventilator einen Motorrahmen (80) umfaßt, der mit der Seitenwand elastisch verbunden ist und axial in die Spirale, im Laufrad, hineinreicht, um den Motor abzustützen.
  8. Ein Zentrifugalventilator nach Anspruch 7, bei dem der Motortragrahmen eine Außenplatte (82) umfaßt, die entlang der genannten Seitenwand verläuft, und einen Käfigabschnitt (84), der axial in die Spirale hineinreicht und in starrer Form mit dem Motor verbunden ist, wobei die genannte elastische Verbindung durch eine Vielzahl von am Umfang angeordneten Schwingungsdämpfern (81) zwischen der Außenplatte und der genannten Seitenwand erreicht wird.
  9. Ein Zentrifugalventilator nach Anspruch 8, bei dem der Käfigabschnitt eine Vielzahl von in axialer Richtung verlaufenden Rippen (85) aufweist, die in dazu passende Ausschnitte im Motoruntersatz passen und die genannte starre Verbindung ergeben.
  10. Ein Zentrifugalventilator nach Anspruch 7 oder Anspruch 8, in welchem die genannte Spiralenseitenwand eine Öffnung aufweist, um einen Lufteintritt zu ermöglichen, und bei dem die Außenplatte der Motortragkonstruktion ringförmig ist, um eine Behinderung des Lufteintritts zu minimieren.
  11. Ein Zentrifugalventilator nach Anspruch 7, bei dem der Motorrahmen aus elastomerem Material ist, um eine Schwingungsdämpfung zu erreichen.
  12. Ein Zentrifugalventilator nach Anspruch 11, bei dem der Motorrahmen (100) drei Beine (103) aufweist, die einen mit dem Motor (102) fest verbundenen Basisteil (101) mit den in der genannten Seitenwand angeordneten jeweiligen Füßen (105) verbinden.
  13. Ein Zentrifugalventilator nach Anspruch 12, bei dem die Beine in ihrer Dicke an der Stelle, wo sie in den Fuß übergehen, reduziert sind, um eine weitere Schwingungsdämpfung zu erzielen.
EP19900307116 1989-07-14 1990-06-28 Gleichstrommotorgetriebener Zentrifugalventilator Revoked EP0408221B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8916214A GB2234012A (en) 1989-07-14 1989-07-14 Dc motor driven centrifugal fan
GB8916214 1989-07-14

Publications (3)

Publication Number Publication Date
EP0408221A2 EP0408221A2 (de) 1991-01-16
EP0408221A3 EP0408221A3 (en) 1991-04-24
EP0408221B1 true EP0408221B1 (de) 1994-09-07

Family

ID=10660081

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19900307116 Revoked EP0408221B1 (de) 1989-07-14 1990-06-28 Gleichstrommotorgetriebener Zentrifugalventilator

Country Status (4)

Country Link
EP (1) EP0408221B1 (de)
JP (1) JPH0350398A (de)
DE (1) DE69012244T2 (de)
GB (1) GB2234012A (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19950245C1 (de) * 1999-10-19 2001-05-10 Ebm Werke Gmbh & Co Kg Radialgebläse
WO2005096715A3 (en) * 2004-04-09 2006-09-08 Lg Electronics Inc Front suction/discharge type outdoor unit for air conditioner and fan using the same
US7861541B2 (en) 2004-07-13 2011-01-04 Tiax Llc System and method of refrigeration
CN101469723B (zh) * 2007-12-28 2012-11-07 Lg电子株式会社 风扇组件

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19740799B4 (de) * 1997-09-17 2006-01-12 Valeo Klimasysteme Gmbh Dämpfungselement
US6315655B1 (en) * 2000-03-01 2001-11-13 Technology Advancement Group, Inc. Low profile computer case and computer
US6712584B2 (en) 2000-04-21 2004-03-30 Revcor, Inc. Fan blade
US6814545B2 (en) 2000-04-21 2004-11-09 Revcor, Inc. Fan blade
US6942457B2 (en) 2002-11-27 2005-09-13 Revcor, Inc. Fan assembly and method
EP2365224B1 (de) * 2010-03-11 2018-04-04 Elica S.p.A. Radialer Förderer für Absaughaube
US10221855B2 (en) * 2012-07-20 2019-03-05 Regal Beloit America, Inc. Furnace air handler blower assembly utilizing a motor connected to an impeller fan that is suspended with mounting arms
US9777735B2 (en) 2012-07-20 2017-10-03 Regal Beloit America, Inc. Blower motor assembly having air directing surface
DE102013204138A1 (de) * 2013-03-11 2014-09-11 BSH Bosch und Siemens Hausgeräte GmbH Lagerschild für einen Gebläsemotor eines Radialgebläses einer Dunstabzugshaube
DE102013204085A1 (de) * 2013-03-11 2014-09-11 BSH Bosch und Siemens Hausgeräte GmbH Doppelflutiges Radialgebläse für eine Dunstabzugshaube
EP3037672B1 (de) * 2014-12-22 2019-09-11 Whirlpool EMEA S.p.A Adapter in einer saugvorrichtung für eine motorhaube
IT201600121296A1 (it) * 2016-11-30 2018-05-30 Elica Spa Soffiatrice radiale
TWI681127B (zh) * 2018-02-01 2020-01-01 大陸商佛山市建準電子有限公司 離心扇及其扇輪
CN118300318B (zh) * 2023-01-04 2025-09-09 九阳股份有限公司 一种食品加工机的降噪效果好的无刷电机

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2966297A (en) * 1957-07-05 1960-12-27 Essick Mfg Company Blower housing
GB968409A (en) * 1961-11-07 1964-09-02 Jan Prosvic Improvements in or relating to centrifugal air blowers
DE1428113B2 (de) * 1962-08-24 1971-01-28 Zinsser. Rudolf. Dr.: Prestl, Karl; 8420Kelheim Gehäuse für ein Kreiselgeblase
GB1131689A (en) * 1966-08-20 1968-10-23 Heidolph Elektro Kg Blowers
GB1168383A (en) * 1968-04-08 1969-10-22 Torin Corp Air Blower and method of assembly thereof
DE1951115B2 (de) * 1969-10-10 1976-10-21 Böhler-Zenkner GmbH & Co KG Strömungstechnik, 4005 Meerbusch Querstromgeblaese
JPS5459605A (en) * 1977-10-20 1979-05-14 Sanyo Electric Co Ltd Blower
FR2461836A1 (fr) * 1979-07-20 1981-02-06 Aero Plast Ventilateur centrifuge
DE3145409A1 (de) * 1981-11-16 1983-05-26 Philipp Hilge Gmbh, 6501 Bodenheim Spiralgehaeuse fuer stroemungsmaschinen und ihre herstellung
GB2133082B (en) * 1982-11-09 1987-05-13 Papst Motoren Gmbh & Co Kg Miniaturized direct current fan
GB2185074B (en) * 1985-11-08 1990-12-19 Papst Motoren Gmbh & Co Kg Fan
GB8705656D0 (en) * 1987-03-10 1987-04-15 Torin Ltd Dc motors
JPS6483894A (en) * 1987-09-28 1989-03-29 Hitachi Ltd Electric blower

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19950245C1 (de) * 1999-10-19 2001-05-10 Ebm Werke Gmbh & Co Kg Radialgebläse
WO2005096715A3 (en) * 2004-04-09 2006-09-08 Lg Electronics Inc Front suction/discharge type outdoor unit for air conditioner and fan using the same
US7861541B2 (en) 2004-07-13 2011-01-04 Tiax Llc System and method of refrigeration
CN101469723B (zh) * 2007-12-28 2012-11-07 Lg电子株式会社 风扇组件
US8337155B2 (en) 2007-12-28 2012-12-25 Lg Electronics Inc. Fan assembly having reduced vibration

Also Published As

Publication number Publication date
DE69012244T2 (de) 1995-03-30
GB8916214D0 (en) 1989-08-31
GB2234012A (en) 1991-01-23
JPH0350398A (ja) 1991-03-04
DE69012244D1 (de) 1994-10-13
EP0408221A2 (de) 1991-01-16
EP0408221A3 (en) 1991-04-24

Similar Documents

Publication Publication Date Title
EP0408221B1 (de) Gleichstrommotorgetriebener Zentrifugalventilator
US7470108B2 (en) Axial flow fan
WO2007079020A2 (en) Reduction of tonal noise in cooling fans using splitter blades
JP5124124B2 (ja) 軸流ファンモータ
US5052888A (en) DC motor driven centrifugal fan
KR100469458B1 (ko) 진동 저감형 송풍기 및 송풍기의 진동 저감 방법
EP1454067A1 (de) Bidirektionales ansaug-zentrifugalgebläse und kühlvorrichtung für rechner
JP2002021782A (ja) 遠心型ファン
JP2003269395A (ja) 軸流ファン
JP4521867B2 (ja) 空気調和機の室外機
JP2005098272A (ja) 遠心ファン
JP4356245B2 (ja) 電動送風機及びそれを搭載した電気掃除機
JP2000120599A (ja) 電動送風機及びそれを搭載した電気掃除機
Gaunt et al. The design and development of a low noise DC motor deriven centrifugal fan
JPH11125197A (ja) 電動送風機
JP4317676B2 (ja) 空気調和機用ターボファン
JP2007183060A (ja) 天井埋込型換気扇
JPH09242693A (ja) 送風機
Neise et al. Active sources in the cutoff of centrifugal fans to reduce the blade tones at higher-order duct mode frequencies
US20080095620A1 (en) Sync method for reducing fan noise
CN223648155U (zh) 一种风机系统、吸油烟机及集成灶
JPWO2019176625A1 (ja) 電動送風機、電気掃除機およびエアタオル
JPH04325855A (ja) ファンモータ
JP2003232296A (ja) 送風ファン
JP2575112Y2 (ja) 送風装置

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: A2

Designated state(s): DE FR GB

17P Request for examination filed

Effective date: 19901213

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE FR GB

17Q First examination report despatched

Effective date: 19920929

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB

REF Corresponds to:

Ref document number: 69012244

Country of ref document: DE

Date of ref document: 19941013

ET Fr: translation filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19950522

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19950606

Year of fee payment: 6

PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19950616

Year of fee payment: 6

26 Opposition filed

Opponent name: EBM ELEKTROBAU MULFINGEN GMBH & CO.

Effective date: 19950607

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

RDAG Patent revoked

Free format text: ORIGINAL CODE: 0009271

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: PATENT REVOKED

27W Patent revoked

Effective date: 19960202

GBPR Gb: patent revoked under art. 102 of the ep convention designating the uk as contracting state

Free format text: 960202