EP1193006A2 - Process for manufacturing a cooled precision casting - Google Patents

Process for manufacturing a cooled precision casting Download PDF

Info

Publication number
EP1193006A2
EP1193006A2 EP01115998A EP01115998A EP1193006A2 EP 1193006 A2 EP1193006 A2 EP 1193006A2 EP 01115998 A EP01115998 A EP 01115998A EP 01115998 A EP01115998 A EP 01115998A EP 1193006 A2 EP1193006 A2 EP 1193006A2
Authority
EP
European Patent Office
Prior art keywords
casting
wax
cooling
core
mold
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
Application number
EP01115998A
Other languages
German (de)
French (fr)
Other versions
EP1193006B1 (en
EP1193006A3 (en
Inventor
Gordon Anderson
Peter Marx
Shailendra Dr. Naik
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.)
General Electric Switzerland GmbH
Original Assignee
General Electric Switzerland GmbH
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
Priority to DE2000138453 priority Critical patent/DE10038453A1/en
Priority to DE10038453 priority
Application filed by General Electric Switzerland GmbH filed Critical General Electric Switzerland GmbH
Publication of EP1193006A2 publication Critical patent/EP1193006A2/en
Publication of EP1193006A3 publication Critical patent/EP1193006A3/en
Application granted granted Critical
Publication of EP1193006B1 publication Critical patent/EP1193006B1/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22CFOUNDRY MOULDING
    • B22C9/00Moulds or cores; Moulding processes
    • B22C9/02Sand moulds or like moulds for shaped castings
    • B22C9/04Use of lost patterns
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22CFOUNDRY MOULDING
    • B22C7/00Patterns; Manufacture thereof so far as not provided for in other classes
    • B22C7/02Lost patterns
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00Metal working
    • Y10T29/49Method of mechanical manufacture
    • Y10T29/49316Impeller making
    • Y10T29/49336Blade making
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00Metal working
    • Y10T29/49Method of mechanical manufacture
    • Y10T29/4998Combined manufacture including applying or shaping of fluent material
    • Y10T29/49988Metal casting
    • Y10T29/49989Followed by cutting or removing material

Abstract

The invention relates to a method for producing a cooled casting (1) of a thermal turbomachine using a known casting method. Between a wax model (10) of the cast part (1) and a ceramic core (6), a wax seal (8) is applied by hand above a step (7) only on an additional shoulder (9). The material that is created during the casting process by the shoulder (9) and the wax seal (8) at this point can be sanded without any unevenness on the step (7). This simplifies the welding or soldering of a cooling plate to step (7). <IMAGE>

Description

TECHNICAL AREA

The invention relates to a method for producing a cooled Investment casting of a thermal turbomachine according to the preamble of Claim 1.

STATE OF THE ART

Castings of thermal turbomachinery are known by Casting process made. Casting furnaces for such casting processes are for example from the documents EP-A1-749 790, US-3,763,926 or US-3,690,367 known. The molds are generally characterized by a Wax model provided. A process for making a complex Part of a gas turbine by means of a casting mold is, for example, from the Document US-5,296,308 known.

Depending on the embodiment, a core is inserted into the wax model. This Core contains the structure of the cavity, which is inside the casting forms a certain cooling structure. With these castings, it must be between the Wax model and the core a wax seal can be attached to one Penetration of the slip, which forms the mold when dry, into the To prevent space. The wax seal is applied to a hand Step, which is next to the core, applied. Ultimately has the stage to include a cooling plate. The cooling plate is on the The stage is soldered or welded and is used for impingement cooling by means of cooling holes the platform below. To avoid leakage the cooling air should be flat on the surface of the step. But this is in Contrary to the attached wax seal, which after casting a Material accumulation above the level results. To the goal of a level Getting closer to the surface of the step is an additional process step such as grinding or eroding.

PRESENTATION OF THE INVENTION

The invention is based on the object of a method for the production of a thermally stressed and cooled casting of a thermal To create turbomachine by means of a known casting process, wherein the casting of the casting with a wax model and a ceramic Core is manufactured, and the subsequent manufacturing steps are simplified and be optimized.

According to the invention, the object is achieved by a method according to the Preamble of claim 1 solved in that before producing the Mold of the casting between the wax model and the core Wax seal is only applied to a paragraph, which is located above the step to the side of the core.

Advantageously, this can be prevented even during the casting process that there are bumps on the step, which is a leak for mean the cooling air on the cooling plate. The material that the Wax seal and the heel created during the casting process can ground down by a unified process step or on others, appropriately removed without unevenness form at the level. At this stage, a cooling plate can be used without further Process steps are soldered.

BRIEF DESCRIPTION OF THE DRAWING

The invention is illustrated with reference to the accompanying drawings, wherein

Fig. 1
shows a model of a turbine blade,
Fig. 2
FIG. 1 shows a section through a turbine blade according to the invention along the line II-II in FIG. 1 and
Fig. 3
shows a section through an inventive turbine blade according to the line II - II in Figure 1 after successful casting process.

Only the elements essential to the invention are shown. The same elements are the same in different drawings Provide reference numerals.

WAY OF CARRYING OUT THE INVENTION

The invention relates to a method for producing a thermal loaded and cooled investment casting of a thermal turbo machine. This can be, for example, a guide or Blade or around other cooled rotor or stator segments one Act gas turbine or a compressor. These castings and that Processes according to the invention for their production are described below explained in more detail with reference to the accompanying figures.

The castings are generally known from the prior art Manufactures casting furnaces. With such a casting furnace can be complex trained and high thermal and mechanical loads removable components are manufactured. Depending on the process conditions it is possible to solidify the casting body in a directed manner. There is the Possibility of using it as a single crystal (SX) or polycrystalline Stem crystals which have a preferred direction ("directionally solidified "(DS). It is particularly important that the directional solidification takes place under conditions in which between a cooled portion of a molten raw material receiving Mold and the still molten starting material a strong one Heat exchange takes place. A zone can then freeze in a directed manner Form materials with a solidification front, which with permanent withdrawal of heat with the formation of the directly solidified casting body by the Mold moves.

Such a method and is for example from the document EP-A1-749 790 a device for producing a directionally solidified casting known. The device consists of a vacuum chamber, which is a contains upper heating chamber and a lower cooling chamber. Both chambers are separated by a baffle. The vacuum chamber holds a mold, which is filled with a melt. For the production of thermal and mechanically resilient parts, as in the case of guide and rotor blades from Gas turbines, for example, will be a superalloy based on Nickel used. In the middle of the baffles there is an opening through which slowly removes the mold from the heating chamber during the process is moved into the cooling chamber so that the casting is from the bottom up directed frozen. The downward movement is done by a drive rod, on which the mold is stored. The bottom of the mold is executed water-cooled. Below the baffles are means to produce and leading a gas flow. These funds provide through the Gas flow next to the lower cooling chamber for additional cooling and thereby for a larger temperature gradient at the Solidification front.

A similar process, which in addition to the heating and cooling chamber with a additional gas cooling works, for example, is also from the Patent US 3,690,367 known.

Another method for producing a directionally solidified casting is known from the document US 3,763,926. With this procedure a mold filled with a molten alloy continuously immersed in a bath heated to approx. 260 ° C. This will create a achieved particularly rapid removal of heat from the mold. This and other, similar processes are known under the term LMC (liquid metal cooling) known.

It is advantageous for the invention to produce this type of casting furnace single-crystal or directionally solidified castings, but it is not limited to that. In principle, the solidification can also be non-directional respectively.

FIG. 1 shows a wax model 10 of a casting 1, for example one to be poured turbine blade. The turbine blade has a platform 2, an airfoil 3 and a blade tip 2. This wax model 10 is then converted into a liquid, ceramic material, which is also a slip is called immersed. This forms around the wax model 10 later casting mold of the casting 1. Then the ceramic Material dried so that the mold with which the casting 1 is produced, arises. After the drying process of the slip the wax is removed by an appropriate heat treatment, i.e. burned out. In this step, the mold is also fired, i.e. in this way it contains its firmness. The casting 1 is so created mold by a known, closer above Cast iron described described manufactured in a known manner. Later that ceramic mold and the core removed in a suitable manner, so for Example using an acid or a base.

The turbine blade of Figure 1 has a cavity in which during the Operation of the turbomachine cooling air is initiated. This cooling air can Leave the finished turbine blade again through cooling holes 5. As from the Figure 1 visible, is in the later cavity of the wax model 10th a ceramic core 6 during the production process of the casting mold, which reflects the internal geometry of the cavity. In the illustrated The turbine 2 is additionally platform 2 by impingement cooling cooled. The cast component is at a level 7 which is located next to the ceramic core 6 and on the edge of the platform 2, a cooling plate 11, in which there are cooling holes 12, soldered or welded. This cooling plate 11 is described in more detail in FIG. 3.

Between the ceramic core 6 and paragraph 9 is before the Manufacture of the mold by hand a wax seal 8 attached. This wax seal 8 has the goal of unwanted penetration of slip to prevent in the interior of the ceramic core 6.

Figure 2 shows a section along the line II - II of Figure 1 through the Stage 7, the wax seal 8 and through the ceramic core 6. According to the invention, the wax seal 8 is only on a shoulder 9 attached, which above level 7 towards the ceramic core 6 located. Various advantages result from this procedure. During the casting process, stage 7 and the Wax seal 8 additional, also cast material on the Turbine blade. As can be seen in FIG. 3, this has a certain one Height s, and can be independent of level 7 or regardless of the Machined surface of level 7, i.e. be sanded. This unified process step can also be done by erosion. The Stage 7, to which the cooling plate 11 is soldered, remains in spite of this additional editing process is unaffected, which in any case is a smooth Level 7 surface guaranteed. The cooling air 13 penetrates through the Cooling holes 12 and can cool the platform 2 by impingement cooling. The Smooth surface of level 7 is so important, because even a small one Unevenness in the cooling performance of this impingement cooling due to leakage losses Reduce. Another advantage is that through the existing Paragraph 9 the liquid solder, which is distributed over the whole stage 7, is prevented from flowing into the cavity of the casting 1. Since the Operation of the casting 1 is also an insert in the cavity, it is important that no solder sticks to this insert and thus the proper functioning is impaired.

LIST OF REFERENCE NUMBERS

1
Cast part, for example turbine blade
2
platform
3
airfoil
4
Tip of the turbine blade
5
cooling holes
6
Ceramic core
7
step
8th
wax seal
9
paragraph
10
Wax model of the turbine blade
11
plate
12
Cooling hole in plate 11
13
cooling air
s
Height of paragraph 9

Claims (5)

  1. Method for producing a cooled casting (1) of a thermal turbomachine using a known casting process, the cooled casting (1) being produced by means of a casting mold, this casting mold using a wax model (10) and a core located in the wax model (10) (6) is produced, a step (7) for fastening a cooling plate (11) to the finished casting (1) being located directly next to the core (6), and a wax seal (8) between the Core (6) and the wax model (10) is attached,
    characterized in that
    Before the casting of the casting (1) is produced between the wax model (10) and the core (6), the wax seal (8) is only applied to a shoulder (9) which is above the step (7) to the side of the core (6 ) there.
  2. Method according to claim 1,
    characterized in that
    after the casting process, the material on the casting (1), which is located at the point of the shoulder (9) and the wax seal (8), is partially ground or eroded, the step (7) being unaffected by this process step.
  3. Method according to claim 2,
    characterized in that
    the cooling plate (11), in which cooling holes (12) are located, is soldered or welded onto the surface of the step (7).
  4. Method according to one of the preceding claims,
    characterized in that
    a casting process is used to produce single-crystal, directional or non-directional solidified castings.
  5. Method according to one of the preceding claims
    characterized in that
    it is a method for producing a guide or rotor blade of a gas turbine or a compressor with an impact cooling of the platform (2).
EP20010115998 2000-08-07 2001-06-30 Process for manufacturing a cooled precision casting Expired - Fee Related EP1193006B1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE2000138453 DE10038453A1 (en) 2000-08-07 2000-08-07 Production of a cooled cast part of a thermal turbo machine comprises applying a wax seal to an offset between a wax model a core before producing the casting mold, the offset being located above the step to the side of the core.
DE10038453 2000-08-07

Publications (3)

Publication Number Publication Date
EP1193006A2 true EP1193006A2 (en) 2002-04-03
EP1193006A3 EP1193006A3 (en) 2003-05-21
EP1193006B1 EP1193006B1 (en) 2005-08-31

Family

ID=7651569

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20010115998 Expired - Fee Related EP1193006B1 (en) 2000-08-07 2001-06-30 Process for manufacturing a cooled precision casting

Country Status (3)

Country Link
US (1) US6435256B1 (en)
EP (1) EP1193006B1 (en)
DE (2) DE10038453A1 (en)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7505980B2 (en) * 2002-11-08 2009-03-17 Crossroads Systems, Inc. System and method for controlling access to multiple physical media libraries
DE10255346A1 (en) * 2002-11-28 2004-06-09 Alstom Technology Ltd Method of making a turbine blade
GB0413027D0 (en) * 2004-06-11 2004-07-14 Rolls Royce Plc A wax recovery method
US20080257517A1 (en) * 2005-12-16 2008-10-23 General Electric Company Mold assembly for use in a liquid metal cooled directional solidification furnace
US9403208B2 (en) 2010-12-30 2016-08-02 United Technologies Corporation Method and casting core for forming a landing for welding a baffle inserted in an airfoil
FR3035604A1 (en) * 2015-04-30 2016-11-04 Snecma Model for lodged model foundation, and model manufacturing method for lost model foundry
US10610933B2 (en) * 2017-02-22 2020-04-07 General Electric Company Method of manufacturing turbine airfoil with open tip casting and tip component thereof
US10625342B2 (en) 2017-02-22 2020-04-21 General Electric Company Method of repairing turbine component
US10717130B2 (en) 2017-02-22 2020-07-21 General Electric Company Method of manufacturing turbine airfoil and tip component thereof
US10702958B2 (en) 2017-02-22 2020-07-07 General Electric Company Method of manufacturing turbine airfoil and tip component thereof using ceramic core with witness feature
US20190309629A1 (en) * 2018-04-05 2019-10-10 United Technologies Corporation Turbine blades and vanes for gas turbine engine

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3177537A (en) * 1962-12-27 1965-04-13 Prec Metalsmiths Inc Methods and apparatus for forming investment molds and mold produced thereby
US3648760A (en) * 1970-04-27 1972-03-14 Abraham J Cooper Precision investment casting apparatus
DE3234658A1 (en) * 1981-10-23 1983-05-05 Howmet Turbine Components Method for forming a crack-free connection between thermoplastic solid bodies
US5489194A (en) * 1990-09-14 1996-02-06 Hitachi, Ltd. Gas turbine, gas turbine blade used therefor and manufacturing method for gas turbine blade
DE3813287C2 (en) * 1987-06-03 1996-09-19 Rolls Royce Plc Process for the manufacture of a metal object
DE19726111C1 (en) * 1997-06-20 1998-11-12 Mtu Muenchen Gmbh Process for the production of a turbomachine blade by casting

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3494709A (en) * 1965-05-27 1970-02-10 United Aircraft Corp Single crystal metallic part
US3690367A (en) * 1968-07-05 1972-09-12 Anadite Inc Apparatus for the restructuring of metals
US3763926A (en) * 1971-09-15 1973-10-09 United Aircraft Corp Apparatus for casting of directionally solidified articles
US5296308A (en) * 1992-08-10 1994-03-22 Howmet Corporation Investment casting using core with integral wall thickness control means
FR2714858B1 (en) * 1994-01-12 1996-02-09 Snecma Method for manufacturing a shell mold made of ceramic material for a lost model foundry.
DE19539770A1 (en) * 1995-06-20 1997-01-02 Abb Research Ltd Process for producing a directionally solidified casting and device for carrying out this process
EP0894558A1 (en) * 1997-07-29 1999-02-03 Siemens Aktiengesellschaft Turbine blade and method of fabrication of a turbine blade

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3177537A (en) * 1962-12-27 1965-04-13 Prec Metalsmiths Inc Methods and apparatus for forming investment molds and mold produced thereby
US3648760A (en) * 1970-04-27 1972-03-14 Abraham J Cooper Precision investment casting apparatus
DE3234658A1 (en) * 1981-10-23 1983-05-05 Howmet Turbine Components Method for forming a crack-free connection between thermoplastic solid bodies
DE3813287C2 (en) * 1987-06-03 1996-09-19 Rolls Royce Plc Process for the manufacture of a metal object
US5489194A (en) * 1990-09-14 1996-02-06 Hitachi, Ltd. Gas turbine, gas turbine blade used therefor and manufacturing method for gas turbine blade
DE19726111C1 (en) * 1997-06-20 1998-11-12 Mtu Muenchen Gmbh Process for the production of a turbomachine blade by casting

Also Published As

Publication number Publication date
US20020029863A1 (en) 2002-03-14
EP1193006A3 (en) 2003-05-21
DE50107262D1 (en) 2005-10-06
DE10038453A1 (en) 2002-02-21
US6435256B1 (en) 2002-08-20
EP1193006B1 (en) 2005-08-31

Similar Documents

Publication Publication Date Title
US9476307B2 (en) Castings, casting cores, and methods
US9435211B2 (en) Method for forming components using additive manufacturing and re-melt
US3536121A (en) Process for producing single crystal metallic alloy objects
US7717676B2 (en) High aspect ratio blade main core modifications for peripheral serpentine microcircuits
EP2246133B1 (en) RMC-defined tip blowing slots for turbine blades
JP4137865B2 (en) Refractory metal core
JP4344787B2 (en) Ceramic core with internal reinforcement
US7234506B2 (en) Ceramic casting core and method
US4008052A (en) Method for improving metallurgical bond in bimetallic castings
US7270173B2 (en) Composite core for use in precision investment casting
US8317475B1 (en) Turbine airfoil with micro cooling channels
US9770758B2 (en) Method for forming a directionally solidified replacement body for a component using additive manufacturing
US10449605B2 (en) Method and apparatus for manufacturing a multi-alloy cast structure
JP4712920B2 (en) Highly depressurized die casting apparatus and casting method
US6340047B1 (en) Core tied cast airfoil
EP1775054B1 (en) Weld closure of through-holes in a nickel-base superalloy hollow airfoil
JP4773457B2 (en) Components with embedded passages, especially hot gas components of turbomachines
US4178986A (en) Furnace for directional solidification casting
US6837417B2 (en) Method of sealing a hollow cast member
EP0749790B2 (en) Apparatus for casting a directionally solidified article
RU2299111C2 (en) Method (variants) and apparatus for making casting mold for casting with use of investment patterns and method for casting with use of investment patterns (variants)
DE602004000347T2 (en) Casting mold for component casting with directional solidification
CN1315594C (en) Investment casting
EP1645347B1 (en) Method for producing a casting of high thermal load
JP2005319518A (en) Method and apparatus for determining location of core generated features in investment casting

Legal Events

Date Code Title Description
AX Request for extension of the european patent to:

Free format text: AL;LT;LV;MK;RO;SI

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

RAP1 Rights of an application transferred

Owner name: ALSTOM (SWITZERLAND) LTD

RIC1 Information provided on ipc code assigned before grant

Ipc: 7B 22C 7/02 B

Ipc: 7B 22C 9/04 A

Ipc: 7B 22D 27/04 B

AX Request for extension of the european patent to:

Extension state: AL LT LV MK RO SI

AK Designated contracting states

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

17P Request for examination filed

Effective date: 20031017

AKX Designation fees paid

Designated state(s): DE GB

RAP1 Rights of an application transferred

Owner name: ALSTOM TECHNOLOGY LTD

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE GB

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REF Corresponds to:

Ref document number: 50107262

Country of ref document: DE

Date of ref document: 20051006

Kind code of ref document: P

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 20051125

26N No opposition filed

Effective date: 20060601

REG Reference to a national code

Ref country code: DE

Ref legal event code: R082

Ref document number: 50107262

Country of ref document: DE

Representative=s name: ROESLER, UWE, DIPL.-PHYS.UNIV., DE

Ref country code: DE

Ref legal event code: R081

Ref document number: 50107262

Country of ref document: DE

Owner name: GENERAL ELECTRIC TECHNOLOGY GMBH, CH

Free format text: FORMER OWNER: ALSTOM TECHNOLOGY LTD., BADEN, CH

Ref country code: DE

Ref legal event code: R081

Ref document number: 50107262

Country of ref document: DE

Owner name: ANSALDO ENERGIA IP UK LIMITED, GB

Free format text: FORMER OWNER: ALSTOM TECHNOLOGY LTD., BADEN, CH

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

Ref country code: DE

Payment date: 20170621

Year of fee payment: 17

Ref country code: GB

Payment date: 20170620

Year of fee payment: 17

REG Reference to a national code

Ref country code: DE

Ref legal event code: R082

Ref document number: 50107262

Country of ref document: DE

Representative=s name: ROESLER, UWE, DIPL.-PHYS.UNIV., DE

Ref country code: DE

Ref legal event code: R081

Ref document number: 50107262

Country of ref document: DE

Owner name: ANSALDO ENERGIA IP UK LIMITED, GB

Free format text: FORMER OWNER: GENERAL ELECTRIC TECHNOLOGY GMBH, BADEN, CH

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

Free format text: REGISTERED BETWEEN 20170824 AND 20170830

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 50107262

Country of ref document: DE

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20180630

PG25 Lapsed in a contracting state [announced from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190101

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180630