US20080298974A1 - Blade of a fluid-flow machine featuring a multi-profile design - Google Patents
Blade of a fluid-flow machine featuring a multi-profile design Download PDFInfo
- Publication number
- US20080298974A1 US20080298974A1 US12/155,014 US15501408A US2008298974A1 US 20080298974 A1 US20080298974 A1 US 20080298974A1 US 15501408 A US15501408 A US 15501408A US 2008298974 A1 US2008298974 A1 US 2008298974A1
- Authority
- US
- United States
- Prior art keywords
- blade
- profile
- percent
- zone
- fore
- 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.)
- Abandoned
Links
- 239000012530 fluid Substances 0.000 description 3
- 230000002349 favourable effect Effects 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000002028 premature Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000003019 stabilising effect Effects 0.000 description 1
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
- F04D29/26—Rotors specially for elastic fluids
- F04D29/32—Rotors specially for elastic fluids for axial flow pumps
- F04D29/321—Rotors specially for elastic fluids for axial flow pumps for axial flow compressors
- F04D29/324—Blades
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
- F01D5/12—Blades
- F01D5/14—Form or construction
- F01D5/141—Shape, i.e. outer, aerodynamic form
- F01D5/145—Means for influencing boundary layers or secondary circulations
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
- F01D5/12—Blades
- F01D5/14—Form or construction
- F01D5/141—Shape, i.e. outer, aerodynamic form
- F01D5/146—Shape, i.e. outer, aerodynamic form of blades with tandem configuration, split blades or slotted blades
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
- F01D5/12—Blades
- F01D5/14—Form or construction
- F01D5/20—Specially-shaped blade tips to seal space between tips and stator
-
- 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
- F04D29/68—Combating cavitation, whirls, noise, vibration or the like; Balancing by influencing boundary layers
- F04D29/681—Combating cavitation, whirls, noise, vibration or the like; Balancing by influencing boundary layers especially adapted for elastic fluid pumps
- F04D29/682—Combating cavitation, whirls, noise, vibration or the like; Balancing by influencing boundary layers especially adapted for elastic fluid pumps by fluid extraction
-
- 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
- F04D29/68—Combating cavitation, whirls, noise, vibration or the like; Balancing by influencing boundary layers
- F04D29/681—Combating cavitation, whirls, noise, vibration or the like; Balancing by influencing boundary layers especially adapted for elastic fluid pumps
- F04D29/684—Combating cavitation, whirls, noise, vibration or the like; Balancing by influencing boundary layers especially adapted for elastic fluid pumps by fluid injection
Definitions
- the present invention relates to blades of fluid-flow machines, such as blowers, compressors, pumps and fans of the axial, semi-axial and radial type using gaseous or liquid working media.
- the fluid-flow machine may include one or several stages, each having a rotor and a stator. In individual cases, the stage can have only a rotor.
- the rotor includes a number of blades, which are connected to the rotating shaft of the machine and transfer energy to the working medium.
- the rotor may be designed with or without a shroud at the outer blade ends.
- the stator includes a number of stationary blades, which may either feature a fixed or a free blade end on the hub and on the casing side.
- Rotor drum and blading are usually enclosed by a casing; in other cases (e.g. aircraft or ship propellers) no such casing exists.
- the machine may also feature a stator, a so-called inlet guide vane assembly, upstream of the first rotor. Departing from the stationary fixation, at least one stator or inlet guide vane assembly may be rotatably borne, to change the angle of attack. Variation is accomplished for example via a spindle accessible from outside of the annulus.
- multi-stage types of said fluid-flow machines may have two counter-rotating shafts, with the direction of rotation of the rotor blade rows alternating between stages. Here, no stators exist between subsequent rotors.
- the fluid-flow machine may—alternatively—feature a bypass configuration such that the single-flow annulus divides into two concentric annuli behind a certain blade row, with each of these annuli housing at least one further blade row.
- FIG. 2 shows examples of four possible configurations of fluid-flow machines, where a casing 1 , a hub/rotor drum 2 , a machine axis 3 and an annulus 9 are indicated in each view, along with the blade configurations.
- the fluid flow in the blade rows of aerodynamically highly loaded fluid-flow machines is characterized by the very high degree of re-direction to be attained.
- the required re-direction of the fluid flow can be so extreme, either in parts of the blade height or along the entire blade height, that premature separation of the boundary layer flow on the blade profile and in the side-wall area on the hub and casing will occur with conventionally designed state-of-the-art blade profile sections.
- Conventional blades without additional design features for stabilising the profile and wall boundary layers, as shown in FIG. 1 are unsuitable due to the occurrence of extremely high pressure losses and the inability to attain the flow re-direction required.
- Blade rows with a profile design according to the state of the art, see FIG. 1 have too small an operating range and too high losses to attain the operating characteristics required for modern fluid-flow machines, this being due to the high aerodynamic loading of the boundary layers, i.e. the two-dimensional boundary layers on the profile and the three-dimensional boundary layers on hub and casing walls.
- the present invention provides for a blade of a fluid-flow machine which is characterized by improved efficiency.
- the present invention provides for a blade for application in a fluid-flow machine which, in at least one part of the annulus width (or the blade height, respectively) in at least one flow-line section, is formed by at least two separate profiles, each of which featuring essentially the shape of a blade profile with a rounded nose (leading edge).
- FIG. 1 is a schematic representation of a blade according to the state of the art
- FIG. 2 shows possible configurations of fluid-flow machines relevant to the present invention
- FIG. 3 shows an example of a blade according to the present invention in schematic representation
- FIG. 4 shows further examples of blades according to the present invention in meridional view
- FIG. 5 provides a definition of meridional flow lines and flow-line profile sections
- FIG. 6 a shows a multi-profile design according to the present invention, as viewed in a flow-line profile section
- FIG. 6 b shows further types of multi-profile design, as viewed in a flow-line profile section
- FIG. 7 a shows examples of a multi-profile design in the center area of a blade, three-dimensional view
- FIG. 7 b shows examples of a multi-profile design at the fixed blade end, three-dimensional view
- FIG. 7 c shows examples of a multi-profile design at the free blade end, three-dimensional view
- FIG. 8 provides a definition of zones for particularly favorable positioning of the fore-profile trailing edge according to the present invention.
- a conventional blade 6 has a leading edge 7 , a trailing edge 8 , a pressure side 5 and a suction side 4 , is positioned between a casing 1 and a hub/rotor drum 2 , and features no subdivision into several, successive profiles over a selected part of the blade height.
- FIG. 1 shows a profile section of the blade on the right of the meridional section shown on the left. In the meridional section, flow takes place from the left to the right, as indicated by the bold arrow. A machine axis 3 is also shown in the meridional section.
- flow around the individual profile sections of the blades takes place separately from the leading edge onward, without fluid communication between the blade sides.
- FIG. 3 shows one embodiment of a blade 6 according to the present invention.
- the blade is shown in meridional section on the left, with flow taking place from the left (left-hand side of the illustration).
- Profile section P-P (taken along section line P-P from the meridional view) is shown on the right in FIG. 3 .
- the blade 6 of the present invention also includes a leading edge 7 , a trailing edge 8 , a pressure side 5 and a suction side 4 , and is positioned between a casing 1 and a hub/rotor drum 2 .
- the blade 6 also has a plurality of passages 10 between the pressure side 5 and the suction side 4 that create several sub-divisions of the profile (see especially the profile section P-P on the right), each featuring different length and shape in the direction of the blade height and being arranged in a selected partial area of the blade height (annulus width).
- the section P-P shown on the right it can be seen how adding the passages 10 to the blade 6 has, in effect, created three separate airfoils on the single blade 6 at that section P-P.
- the present invention obviously also applies to blades featuring a larger or a smaller number of subdivisions and the passages 10 can be numbered and configured as desired to provide a desired result at various heights along a blade 6 .
- FIG. 4 shows further embodiments of blades according to the present invention having different quantities and configurations of passages 10 to create unique sets of subdivisions and airfoil configurations at various heights of the disclosed blades 6 .
- example (a.) shows a single passage 10 creating a profile subdivision in the center area of the blade 6 .
- Example (b.) shows two successive passages 10 creating profile subdivisions in the center area of the blade 6 .
- Example (c.) shows a blade with a free end adjacent the casing 1 and passages 10 at the inner and outer ends of the blade 6 creating respective profile subdivisions.
- Example (d.) shows two obliquely oriented passages 10 creating profile subdivisions arranged in the area of the trailing-edge 8 near the hub 2 and the casing 1 .
- Example (e.) shows a single passage 10 creating a profile subdivision near the casing 1 in the area of the trailing-edge 8 .
- Example (f.) shows a blade 6 with a free end adjacent the hub 2 and having passages 10 at the inner and outer ends of the blade 6 to create smaller profile subdivisions at the blade ends.
- FIG. 5 provides a precise definition of meridional flow lines and flow-line profile sections.
- the mean meridional flow line m is established by the geometrical center of the annulus 9 between the casing 1 and the hub/rotor drum 2 . If a perpendicular is erected at any point of the mean flow line m, the development of annulus width W along the flow path and a number of perpendiculars is obtained by use of which, with equal relative division of the perpendiculars in the direction of the annulus width, further meridional flow lines m n may be determined.
- the section of a meridional flow line m with a blade 6 provides a flow-line profile section. Further considerations on the blade 6 according to the present invention are based on flow-line profile sections.
- FIG. 6 a shows blade configurations according to the present invention in a selected flow-line profile section.
- FIG. 6 b shows further arrangements featuring a multi-profile design according to the present invention, again in a flow-line profile section.
- Representation (5.) provides a profile subdivision into three individual profiles (fore-profile, first aft-profile and second aft-profile) with the fore-profile being slender relative to the first and second aft-profile.
- Representation (6.) provides a profile subdivision into three individual profiles (fore-profile, first aft-profile and second aft-profile), with all three profiles having small, but approximately equal relative thickness (less than 5 percent).
- FIGS. 7 a to 7 c show inventive configurations of the multi-profile design in different blade areas.
- FIG. 7 a shows two different blades, confined by two blade ends not further specified, with sectional subdivision into fore-profile and first aft-profile (N2) in the center area of the blade, with the subdivision zone not reaching the ends of the blade. While the blade on the left has one area in multi-profile design, the blade on the right features multi-profile design in two areas of the blade height.
- This arrangement applies, in particular, to the blade ends on rotor or stator platforms, as defined by the blade roots or shrouds.
- the multi-profile design in the forward subdivision zone is oriented essentially in flow direction
- the multi-profile design in the rearward subdivision zone shows orientation towards the free blade end, characterized in that the passage 10 between the partial profiles provides for a contracting flow path, as viewed in the blade height direction.
- This arrangement applies, in particular, to the blade tips of rotors and to the tips of cantilevered stators with a radial gap at the hub.
- the trailing edge of the fore-profile in the trailing edge and rim-near zone (TRZ) of a blade 6 , see FIG. 8 .
- the trailing edge-near zone is defined as the portion of the blade between 40 percent and 100 percent of the meridional blade chord length Cm.
- the rim-near zone is defined as the blade portions between 0 percent and 40 percent as well as between 60 percent and 100 percent of the annulus width (blade height).
- the present invention provides for a significantly higher aerodynamic loadability of rotors and stators in fluid-flow machines, with efficiency being maintained or even improved. A reduction of the number of parts and the weight of the components of more than 20 percent seems to be achievable. Application of the concept to the high-pressure compressor of an aircraft engine with approx. 25,000 lbs thrust leads to a reduction of the specific fuel consumption of up to 0.5 percent.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
- Turbine Rotor Nozzle Sealing (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102007024840.9 | 2007-05-29 | ||
DE102007024840A DE102007024840A1 (de) | 2007-05-29 | 2007-05-29 | Strömungsarbeitsmaschinenschaufel mit Multi-Profil-Gestaltung |
Publications (1)
Publication Number | Publication Date |
---|---|
US20080298974A1 true US20080298974A1 (en) | 2008-12-04 |
Family
ID=39577290
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/155,014 Abandoned US20080298974A1 (en) | 2007-05-29 | 2008-05-29 | Blade of a fluid-flow machine featuring a multi-profile design |
Country Status (3)
Country | Link |
---|---|
US (1) | US20080298974A1 (de) |
EP (1) | EP1998049A3 (de) |
DE (1) | DE102007024840A1 (de) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20120148396A1 (en) * | 2010-12-08 | 2012-06-14 | Rolls-Royce Deutschland Ltd & Co Kg | Fluid-flow machine - blade with hybrid profile configuration |
CN102536327A (zh) * | 2011-12-07 | 2012-07-04 | 北京航空航天大学 | 一种兼顾气动与结构特征的航空发动机风扇叶片三维几何结构 |
US20130209224A1 (en) * | 2012-02-10 | 2013-08-15 | Mtu Aero Engines Gmbh | Turbomachine |
WO2014184727A1 (en) * | 2013-05-14 | 2014-11-20 | Cofimco S.R.L. | Axial fan |
US9638040B2 (en) | 2011-09-29 | 2017-05-02 | Rolls-Royce Deutschland Ltd & Co Kg | Blade of a row of rotor blades or stator blades for use in a turbomachine |
EP3070264A4 (de) * | 2013-11-15 | 2017-06-21 | IHI Corporation | Schaufelstruktur für eine axial durchströmte turbomaschine und gasturbinenmotor |
US9822645B2 (en) | 2014-02-27 | 2017-11-21 | Rolls-Royce Deutschland Ltd & Co Kg | Group of blade rows |
US20170335860A1 (en) * | 2016-05-20 | 2017-11-23 | United Technologies Corporation | Tandem tip blade |
US11421702B2 (en) | 2019-08-21 | 2022-08-23 | Pratt & Whitney Canada Corp. | Impeller with chordwise vane thickness variation |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10323528B2 (en) * | 2015-07-01 | 2019-06-18 | General Electric Company | Bulged nozzle for control of secondary flow and optimal diffuser performance |
HUP1600523A2 (en) * | 2016-09-07 | 2018-03-28 | Attila Nyiri | Regulation of blades for airscrew, blower or wind turbine by holes, slots and notches |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US285212A (en) * | 1883-09-18 | Screw-propeller | ||
US680671A (en) * | 1901-05-02 | 1901-08-13 | Myers Screw Propeller Syndicate Ltd | Screw-propeller. |
US1344496A (en) * | 1917-10-06 | 1920-06-22 | Albert L Flattum | Aerial propeller |
US3044559A (en) * | 1959-07-14 | 1962-07-17 | Chajmik Joseph | Propeller |
US20050129518A1 (en) * | 2003-12-12 | 2005-06-16 | Siemens Vdo Automotive Inc. | Low pressure fan with Y-shaped blades |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FI74115C (fi) * | 1981-03-27 | 1987-12-10 | Foehn Oy | Propeller. |
EP0295353B1 (de) * | 1987-06-13 | 1991-04-17 | Khammas, Achmed Adolf Wolfgang | Rotorblatt |
JP3582363B2 (ja) * | 1998-06-25 | 2004-10-27 | ダイキン工業株式会社 | 送風機用羽根車 |
-
2007
- 2007-05-29 DE DE102007024840A patent/DE102007024840A1/de not_active Withdrawn
-
2008
- 2008-05-15 EP EP08009031A patent/EP1998049A3/de not_active Withdrawn
- 2008-05-29 US US12/155,014 patent/US20080298974A1/en not_active Abandoned
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US285212A (en) * | 1883-09-18 | Screw-propeller | ||
US680671A (en) * | 1901-05-02 | 1901-08-13 | Myers Screw Propeller Syndicate Ltd | Screw-propeller. |
US1344496A (en) * | 1917-10-06 | 1920-06-22 | Albert L Flattum | Aerial propeller |
US3044559A (en) * | 1959-07-14 | 1962-07-17 | Chajmik Joseph | Propeller |
US20050129518A1 (en) * | 2003-12-12 | 2005-06-16 | Siemens Vdo Automotive Inc. | Low pressure fan with Y-shaped blades |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9394794B2 (en) * | 2010-12-08 | 2016-07-19 | Rolls-Royce Deutschland Ltd & Co Kg | Fluid-flow machine—blade with hybrid profile configuration |
US20120148396A1 (en) * | 2010-12-08 | 2012-06-14 | Rolls-Royce Deutschland Ltd & Co Kg | Fluid-flow machine - blade with hybrid profile configuration |
US9638040B2 (en) | 2011-09-29 | 2017-05-02 | Rolls-Royce Deutschland Ltd & Co Kg | Blade of a row of rotor blades or stator blades for use in a turbomachine |
CN102536327A (zh) * | 2011-12-07 | 2012-07-04 | 北京航空航天大学 | 一种兼顾气动与结构特征的航空发动机风扇叶片三维几何结构 |
US20130209224A1 (en) * | 2012-02-10 | 2013-08-15 | Mtu Aero Engines Gmbh | Turbomachine |
US10184339B2 (en) * | 2012-02-10 | 2019-01-22 | Mtu Aero Engines Gmbh | Turbomachine |
WO2014184727A1 (en) * | 2013-05-14 | 2014-11-20 | Cofimco S.R.L. | Axial fan |
US20160138601A1 (en) * | 2013-05-14 | 2016-05-19 | Cofimco S.R.L. | Axial fan |
US10036392B2 (en) * | 2013-05-14 | 2018-07-31 | Cofimco S.R.L. | Axial fan for industrial use |
CN105358836A (zh) * | 2013-05-14 | 2016-02-24 | 可风可有限公司 | 轴流式风扇 |
EP3070264A4 (de) * | 2013-11-15 | 2017-06-21 | IHI Corporation | Schaufelstruktur für eine axial durchströmte turbomaschine und gasturbinenmotor |
US9822645B2 (en) | 2014-02-27 | 2017-11-21 | Rolls-Royce Deutschland Ltd & Co Kg | Group of blade rows |
US20170335860A1 (en) * | 2016-05-20 | 2017-11-23 | United Technologies Corporation | Tandem tip blade |
US10151322B2 (en) * | 2016-05-20 | 2018-12-11 | United Technologies Corporation | Tandem tip blade |
US11421702B2 (en) | 2019-08-21 | 2022-08-23 | Pratt & Whitney Canada Corp. | Impeller with chordwise vane thickness variation |
Also Published As
Publication number | Publication date |
---|---|
EP1998049A2 (de) | 2008-12-03 |
EP1998049A3 (de) | 2010-06-09 |
DE102007024840A1 (de) | 2008-12-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20080298974A1 (en) | Blade of a fluid-flow machine featuring a multi-profile design | |
US8534997B2 (en) | Fluid flow machine with a blade row group featuring a meridional edge distance | |
US8152467B2 (en) | Blade with tangential jet generation on the profile | |
US8043046B2 (en) | Fluid flow machine with blade row-internal fluid return arrangement | |
US8257022B2 (en) | Fluid flow machine featuring a groove on a running gap of a blade end | |
US8251648B2 (en) | Casing treatment for axial compressors in a hub area | |
US7077623B2 (en) | Fluid flow machine with integrated fluid circulation system | |
US20090041576A1 (en) | Fluid flow machine featuring an annulus duct wall recess | |
US7967556B2 (en) | Turbomachine with means for the creation of a peripheral jet on the stator | |
US8202044B2 (en) | Blade shroud with protrusion | |
US8220276B2 (en) | Gas-turbine compressor with bleed-air tapping | |
US7364404B2 (en) | Turbomachine with fluid removal | |
US8690523B2 (en) | Fluid flow machine with running gap retraction | |
US9726197B2 (en) | Turbomachine element | |
US8308429B2 (en) | Axial compressor | |
US20090317232A1 (en) | Blade shroud with aperture | |
US8403630B2 (en) | Blade shroud with fluid barrier jet generation | |
EP3163028A1 (de) | Verdichtervorrichtung | |
US9951635B2 (en) | Group of blade rows | |
EP2441964B1 (de) | Verfahren zum Schaufelentwurf für einen Axialverdichter und Axialverdichter | |
US20180017079A1 (en) | Variable-cycle compressor with a splittered rotor | |
US6877953B2 (en) | Gas turbine | |
EP3372786B1 (de) | Hochdruckverdichterrotorschaufel mit vorderkante mit einkerbungssegment | |
RU2727823C2 (ru) | Лопатка ротора турбомашины, диск с лопатками, ротор и турбомашина | |
EP4144958B1 (de) | Strömungmaschine für ein flugzeugtriebwerk und flugzeugtriebwerk |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ROLLS-ROYCE DEUTSCHLAND LTD & CO KG, GERMANY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:GUEMMER, VOLKER;REEL/FRAME:021070/0671 Effective date: 20080521 |
|
STCB | Information on status: application discontinuation |
Free format text: EXPRESSLY ABANDONED -- DURING EXAMINATION |