CA1192716A - Method of producing insulated pipeline components - Google Patents
Method of producing insulated pipeline componentsInfo
- Publication number
- CA1192716A CA1192716A CA000422251A CA422251A CA1192716A CA 1192716 A CA1192716 A CA 1192716A CA 000422251 A CA000422251 A CA 000422251A CA 422251 A CA422251 A CA 422251A CA 1192716 A CA1192716 A CA 1192716A
- Authority
- CA
- Canada
- Prior art keywords
- mold
- inner pipe
- pipe
- plastic
- cavity
- 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.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L59/00—Thermal insulation in general
- F16L59/04—Arrangements using dry fillers, e.g. using slag wool which is added to the object to be insulated by pouring, spreading, spraying or the like
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L59/00—Thermal insulation in general
- F16L59/14—Arrangements for the insulation of pipes or pipe systems
- F16L59/16—Arrangements specially adapted to local requirements at flanges, junctions, valves or the like
- F16L59/22—Arrangements specially adapted to local requirements at flanges, junctions, valves or the like adapted for bends
Abstract
CANADIAN PATENT APPLICATION
OF
OLLE KRISTENSSON
AND
BO ROLF GUNNAR NYSTR?M
FOR
A METHOD OF PRODUCING INSULATED
PIPELINE COMPONENTS
Abstract of the Disclosure Insulated pipeline components are produced by posi-tioning a steel pipe in the cavity of a casting mold with the pipe ends protruding therefrom. The dimensions of the cavity are greater than those of the inner pipe, and in the space between the inner pipe and the contact surfaces of the mold cavity a plastic powder is positioned which is molten by heating of the mold. The mold is then rotated in a manner well known in rotational molding technique, and after the mold has cooled the component is removed and expandable plastic material is supplied to the space between the inner pipe and the jacket and is foamed in known manner. A component produced by the method according to the invention has an exactly centered inner pipe, lacks conventional joints and can be produced at rela-tively low cost in a manner complying with industrial safety requirements.
OF
OLLE KRISTENSSON
AND
BO ROLF GUNNAR NYSTR?M
FOR
A METHOD OF PRODUCING INSULATED
PIPELINE COMPONENTS
Abstract of the Disclosure Insulated pipeline components are produced by posi-tioning a steel pipe in the cavity of a casting mold with the pipe ends protruding therefrom. The dimensions of the cavity are greater than those of the inner pipe, and in the space between the inner pipe and the contact surfaces of the mold cavity a plastic powder is positioned which is molten by heating of the mold. The mold is then rotated in a manner well known in rotational molding technique, and after the mold has cooled the component is removed and expandable plastic material is supplied to the space between the inner pipe and the jacket and is foamed in known manner. A component produced by the method according to the invention has an exactly centered inner pipe, lacks conventional joints and can be produced at rela-tively low cost in a manner complying with industrial safety requirements.
Description
'7~
The present invention relates to a rnethod of produciny insulated pipeline components consi5ting of a fluid-conducting inner pipe~ preferably of steel, an outer casing of rigid plastic, for instance polyethylene, and an intermediate in-sulating layer of foame~ pla5tic material, for instance poly-urethane foam.
Pipelines in district heating systems consist both of straight pipe elements and of components in the form of elbows, tees, reducing pieces t crosses~ expansion pipes etc.
all of which have an inner pipe of steel, an outer pipe of rigid plastic and an intermediate insulation of expanded material. While the straight pipe elements are readily manu-factured, production of the other components is not an easy matter. For example, an insulated elbow is manufactured by dividing a curved rigid plastic pipe with a diameter much larger than that of the steel pipe into three or more seg-ments which are then pushed onto the steel pipe and again joined together, for instance by polyfusion or extrusion welding The steel pipe is then centered as exactly as pos-sible within the plastic pipe, and the ends of the plastic pipe are sealed~ whereupon the space between the steel pipe and $he plastic pipe is filled with polyurethane. Pipe com ponents manufactured in this manner suffer from several dis-advantages. First of all, their production is difficult because of the complicated welding of the segments or the like, and frequently leakage occurs at the joints during 27 subsequent use It is also difficult to center the inner pipe within the jacket and last but not least the final
The present invention relates to a rnethod of produciny insulated pipeline components consi5ting of a fluid-conducting inner pipe~ preferably of steel, an outer casing of rigid plastic, for instance polyethylene, and an intermediate in-sulating layer of foame~ pla5tic material, for instance poly-urethane foam.
Pipelines in district heating systems consist both of straight pipe elements and of components in the form of elbows, tees, reducing pieces t crosses~ expansion pipes etc.
all of which have an inner pipe of steel, an outer pipe of rigid plastic and an intermediate insulation of expanded material. While the straight pipe elements are readily manu-factured, production of the other components is not an easy matter. For example, an insulated elbow is manufactured by dividing a curved rigid plastic pipe with a diameter much larger than that of the steel pipe into three or more seg-ments which are then pushed onto the steel pipe and again joined together, for instance by polyfusion or extrusion welding The steel pipe is then centered as exactly as pos-sible within the plastic pipe, and the ends of the plastic pipe are sealed~ whereupon the space between the steel pipe and $he plastic pipe is filled with polyurethane. Pipe com ponents manufactured in this manner suffer from several dis-advantages. First of all, their production is difficult because of the complicated welding of the segments or the like, and frequently leakage occurs at the joints during 27 subsequent use It is also difficult to center the inner pipe within the jacket and last but not least the final
2 ~
'7~
insulation with polyurethane foam is unsatisfactory with respect to industrial safety requirements. Production of these components thus is difficult and therefore expensive, while at the same time the quality often is not entirely satisfactory.
It is the object of the present invention to obviate the above-men~ioned disadvantages of insulated pipeline components and to produce, in a simple manner, better and less expensive components. This is achieved by oentering the inner pipe in the mold cavity of a two-part mold with the pipe ends protruding therefrom, charging the mold cavity whose dimensions are greater than those of the inner pipe, with rigid plastic powder~ closing the mold and heating it to melt the plastic powder and then rotating the mold in a manner well known in rotational molding technique to produce a plastic layer around the contact surfaces of the mold cavity, removing the inner pipe and the surrounding plastic jacket from the mold after the mold has cooled, and supplying the expandable plas~ic material to the space between the inner pipe and the jacket where it is expanded in known manner.
The invention will be described in more detail below, reference being had to the accompanying drawing in which:
Fig. 1 illustrates schematically a mold for the production of a pipeline component in the form of an elbow; and Fig. 2 shows a section of the finished pipe component.
27 An insulated elbow for a pipeline in a district heating system is produced by means of a two-part mold~ one mold part of which is designated 11 in Fig. 1. The mold part 11 has a cavity 12 for accommodating the fluid-conducting inner pipe 10 of steelO As will appear from Fig. 1, the cavity 12 has a much greater radius than the inner pipe 10, but is shorter than the pipe so that mold end walls are formed which have a central recess 13 of the same radius as the inner pipe 10. The pipe 10 thus can be positioned in the mold part 11 with its ends resting in the semicircular recesses 13 of the mold end pieces. Although Fig. 1 shows the end faces of the pipe 10 flush with the outer side of the end walls, the pipe end faces may, if desired, also extend beyond this surface.
The recesses in the end walls of the mold 11 tightly surround the pipe, and if necessary it is~ of course, also possible to provide a sealing material around the pipe end portions at the point where they extend through the pipe end walls so that the cavity 12 will be sealed towards the atmosphere.
When the inner pipe 10 thus has been placed in the mold part 11 and the mold is closed by bringing the mold part 11 together with an identical part, the inner pipe 10 will be exactly centered in the mold cavity 12. Before the pipe is placed in ~he cavity, a ring of some suitable material, for instance paper or aluminum~ preferably is disposed about a portion of the pipe which lies at some distance from the point where the tube 10 projects from the mold cavity 12, such that a narrow gap is formed between the ring 14 and the inner surface of the mold end walls. The rings 14 may 27 be formed by a foil wrapping~ or by passing resilient means onto the pipe. Before the mold is closedl a predetermined '7~6 amount of rigid plastic powder is introduced into the cavity 12. The terrn "rigid plastic" is here used for any type of plastic suitable for the production of a relatively rigid outer jacket capable of withstanding mechanical stresses and chemical attack. A suitable material is polyethylene.
After the mold has been closed, it is heated, for instance by means of heating coils (not shown) in the mold itself, or by placing the mold in an oven so that the plastic powder within the mold cavity 12 will melt. The mold is then .otated in different planes in a manner well known in rotational molding technique~ whereby the ~lten plastic flows out and covers the contact surfaces of the mold cavity 12, as shown in Fig. 1. The rings 14 serve to prevent the molten plastic from leaving the space adjacent the mold end walls along the pipe. After rotational molding, the mold is cooled, for instance by means of cooling passages (not shown) t and when the mold is sufficiently cool, it can be opened and the inner pipe 10 which now is provided with a plastic jacket 15, can be removed. As has been pointed out before D this technique ensures that the pipe 10 will be exactly centered within the jacket 15, which is important in order to prevent undesired heat losses later on. Furthermore, the rotational molding gives a whole jacket without joints and of uniform wall thickness.
The component thus produced must now be insulated, and this is done by making one or more holes in the plastic 27 jacket, preferably in one of its end wall portions. An e~-pandable material preferably expandable polyurethane, is now '7~
injected through the hole or holes and is caused to expand in the space between the inner pipe 10 and the jacket 15 in conventional manner. The injection hole or holes are then sealed. It should be stressed that, by the method accord-ing to the present invention, the in many respects complicated and hazardous insulation of the pipe component with expandable plastic can be carried out entirely without risk and in a manner complying with industrial safety requirements. Th~
pipe component is now ready for connection in a pipeline system.
In many instances, it is desired to provide alarm wires 17 sensing a possible infiltration or leakage of liquid in the insulation and activating a signalling device in the insulation layer, which is easily done by placing the wires in the mold together with the inner pipe 10, where~
by the plastic material during the subsequent rotational molding will tightly surround the wires at the points where they projec~ from the plastic jacket.
The drawing illustrates the production of an insulated elbow, but it will be appreciated that also all other in-sulated components of a pipeline, such as tees, reducing pieces, crosses, expansion pieces etc. are readily manufac-tured by the same technique.
'7~
insulation with polyurethane foam is unsatisfactory with respect to industrial safety requirements. Production of these components thus is difficult and therefore expensive, while at the same time the quality often is not entirely satisfactory.
It is the object of the present invention to obviate the above-men~ioned disadvantages of insulated pipeline components and to produce, in a simple manner, better and less expensive components. This is achieved by oentering the inner pipe in the mold cavity of a two-part mold with the pipe ends protruding therefrom, charging the mold cavity whose dimensions are greater than those of the inner pipe, with rigid plastic powder~ closing the mold and heating it to melt the plastic powder and then rotating the mold in a manner well known in rotational molding technique to produce a plastic layer around the contact surfaces of the mold cavity, removing the inner pipe and the surrounding plastic jacket from the mold after the mold has cooled, and supplying the expandable plas~ic material to the space between the inner pipe and the jacket where it is expanded in known manner.
The invention will be described in more detail below, reference being had to the accompanying drawing in which:
Fig. 1 illustrates schematically a mold for the production of a pipeline component in the form of an elbow; and Fig. 2 shows a section of the finished pipe component.
27 An insulated elbow for a pipeline in a district heating system is produced by means of a two-part mold~ one mold part of which is designated 11 in Fig. 1. The mold part 11 has a cavity 12 for accommodating the fluid-conducting inner pipe 10 of steelO As will appear from Fig. 1, the cavity 12 has a much greater radius than the inner pipe 10, but is shorter than the pipe so that mold end walls are formed which have a central recess 13 of the same radius as the inner pipe 10. The pipe 10 thus can be positioned in the mold part 11 with its ends resting in the semicircular recesses 13 of the mold end pieces. Although Fig. 1 shows the end faces of the pipe 10 flush with the outer side of the end walls, the pipe end faces may, if desired, also extend beyond this surface.
The recesses in the end walls of the mold 11 tightly surround the pipe, and if necessary it is~ of course, also possible to provide a sealing material around the pipe end portions at the point where they extend through the pipe end walls so that the cavity 12 will be sealed towards the atmosphere.
When the inner pipe 10 thus has been placed in the mold part 11 and the mold is closed by bringing the mold part 11 together with an identical part, the inner pipe 10 will be exactly centered in the mold cavity 12. Before the pipe is placed in ~he cavity, a ring of some suitable material, for instance paper or aluminum~ preferably is disposed about a portion of the pipe which lies at some distance from the point where the tube 10 projects from the mold cavity 12, such that a narrow gap is formed between the ring 14 and the inner surface of the mold end walls. The rings 14 may 27 be formed by a foil wrapping~ or by passing resilient means onto the pipe. Before the mold is closedl a predetermined '7~6 amount of rigid plastic powder is introduced into the cavity 12. The terrn "rigid plastic" is here used for any type of plastic suitable for the production of a relatively rigid outer jacket capable of withstanding mechanical stresses and chemical attack. A suitable material is polyethylene.
After the mold has been closed, it is heated, for instance by means of heating coils (not shown) in the mold itself, or by placing the mold in an oven so that the plastic powder within the mold cavity 12 will melt. The mold is then .otated in different planes in a manner well known in rotational molding technique~ whereby the ~lten plastic flows out and covers the contact surfaces of the mold cavity 12, as shown in Fig. 1. The rings 14 serve to prevent the molten plastic from leaving the space adjacent the mold end walls along the pipe. After rotational molding, the mold is cooled, for instance by means of cooling passages (not shown) t and when the mold is sufficiently cool, it can be opened and the inner pipe 10 which now is provided with a plastic jacket 15, can be removed. As has been pointed out before D this technique ensures that the pipe 10 will be exactly centered within the jacket 15, which is important in order to prevent undesired heat losses later on. Furthermore, the rotational molding gives a whole jacket without joints and of uniform wall thickness.
The component thus produced must now be insulated, and this is done by making one or more holes in the plastic 27 jacket, preferably in one of its end wall portions. An e~-pandable material preferably expandable polyurethane, is now '7~
injected through the hole or holes and is caused to expand in the space between the inner pipe 10 and the jacket 15 in conventional manner. The injection hole or holes are then sealed. It should be stressed that, by the method accord-ing to the present invention, the in many respects complicated and hazardous insulation of the pipe component with expandable plastic can be carried out entirely without risk and in a manner complying with industrial safety requirements. Th~
pipe component is now ready for connection in a pipeline system.
In many instances, it is desired to provide alarm wires 17 sensing a possible infiltration or leakage of liquid in the insulation and activating a signalling device in the insulation layer, which is easily done by placing the wires in the mold together with the inner pipe 10, where~
by the plastic material during the subsequent rotational molding will tightly surround the wires at the points where they projec~ from the plastic jacket.
The drawing illustrates the production of an insulated elbow, but it will be appreciated that also all other in-sulated components of a pipeline, such as tees, reducing pieces, crosses, expansion pieces etc. are readily manufac-tured by the same technique.
Claims (4)
1. A method of producing insulated pipeline components consisting of a fluid-conducting inner pipe, an outer casing of rigid plastic, and an intermediate insulating layer of foamed plastic material, which comprises centering the inner pipe in a mold cavity of a two-part mold with the pipe ends protruding therefrom; charging the mold cavity whose dimensions are greater than those of the inner pipe with plastic powder; closing the mold and heating it to melt the plastic powder and then rotating the mold to produce a plastic layer around the contact surfaces of the mold cavity; removing the inner pipe and the surrounding plastic jacket from the mould after the mold has cooled;
supplying an expandable plastic material to the space between the inner pipe and the jacket and expanding the expandable plastic material to form said insulating layer.
supplying an expandable plastic material to the space between the inner pipe and the jacket and expanding the expandable plastic material to form said insulating layer.
2. A method as claimed in claim 1, wherein there is disposed on the inner pipe, before it is placed in the mold, a ring around said inner pipe at some distance from those points in the mold cavity from which the pipe ends protrude to prevent the molten plastic from flowing along the pipe.
3. A method as claimed in claim 1 or 2, characterized in that at least one hole is made in the rotationally molded jacket, preferably in one of the surfaces adjacent the inner pipe, through which hole is expandable plastic material is injected into the space between the inner pipe and the jacket and is caused to expand, whereupon the hole is sealed.
4. A method as claimed in claims 1 or 2, characterized in that alarm wires are placed in the mold cavity together with the inner tube and with the ends of said wires protruding from said cavity.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE8201114-9 | 1982-02-23 | ||
| SE8201114A SE434815B (en) | 1982-02-23 | 1982-02-23 | SET FOR MANUFACTURE OF ISOLATED PIPE CONTROL PARTS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1192716A true CA1192716A (en) | 1985-09-03 |
Family
ID=20346081
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000422251A Expired CA1192716A (en) | 1982-02-23 | 1983-02-23 | Method of producing insulated pipeline components |
Country Status (11)
| Country | Link |
|---|---|
| US (1) | US4485057A (en) |
| BE (1) | BE895954A (en) |
| CA (1) | CA1192716A (en) |
| CH (1) | CH662086A5 (en) |
| DE (1) | DE3305808A1 (en) |
| DK (1) | DK64783A (en) |
| FI (1) | FI830521L (en) |
| FR (1) | FR2522112B1 (en) |
| NL (1) | NL8300651A (en) |
| NO (1) | NO830609L (en) |
| SE (1) | SE434815B (en) |
Families Citing this family (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61162328A (en) * | 1985-01-11 | 1986-07-23 | Toyota Motor Corp | Molding method of skin in integral foaming |
| EP0190103A3 (en) * | 1985-01-28 | 1988-11-30 | AUF DER MAUR, Adolf | Insulated pipe bends for the construction of distant-heating plants |
| US5051285A (en) * | 1988-07-29 | 1991-09-24 | Pillard Products, Inc. | Plastic piling |
| US5180531A (en) * | 1988-07-29 | 1993-01-19 | Vartkes Borzakian | Method of forming plastic piling |
| NO176510C (en) * | 1990-08-16 | 1995-04-19 | Nordic Ind As | Storage container for foodstuffs |
| DE4118362A1 (en) * | 1991-06-05 | 1992-12-10 | Bayer Ag | METHOD OF ISOLATING PIPES |
| AU668470B2 (en) * | 1993-07-12 | 1996-05-02 | Seaward International, Inc. | Elongated structural member and method and apparatus for making same |
| DE4405061A1 (en) * | 1994-02-17 | 1995-08-24 | Bayer Ag | Process for the insulation of pipes with rigid polyurethane foams by the rotational molding process |
| US5766711A (en) * | 1996-08-29 | 1998-06-16 | Barmakian; Andrew | Composite camel structure and method for manufacture |
| US5937521A (en) * | 1997-05-23 | 1999-08-17 | Seaward International, Inc. | Method of making extruded plastic members |
| US6161985A (en) * | 1997-12-11 | 2000-12-19 | Vernon W. Hinkle | Manhole collar assembly |
| US6338366B1 (en) | 2001-01-11 | 2002-01-15 | David R. Williams | Pipe insulation with a jacket measured in fractions of an inch |
| KR20040011226A (en) * | 2002-07-29 | 2004-02-05 | 조병우 | The exterior finish all style lagging charge method of construction for complicated structure part of piping line |
| US20050180822A1 (en) * | 2004-02-18 | 2005-08-18 | Andrew Barmakian | Composite structure |
| US7563496B2 (en) * | 2005-05-18 | 2009-07-21 | Watson William R | Composite pipe |
| NZ541983A (en) * | 2005-08-23 | 2007-06-29 | Gallagher Group Ltd | Method of forming a housing by rotation moulding around an antenna |
| US8714206B2 (en) * | 2007-12-21 | 2014-05-06 | Shawcor Ltd. | Styrenic insulation for pipe |
| US8397765B2 (en) * | 2008-07-25 | 2013-03-19 | Shawcor Ltd. | High temperature resistant insulation for pipe |
| BRPI0924891B1 (en) * | 2008-12-22 | 2020-01-28 | Shawcor Ltd | rollable styrenic insulation for pipes |
| KR101298656B1 (en) * | 2011-03-30 | 2013-08-21 | 한국지역난방공사 | Shape tube for district heating heat pipe having shear control ring |
| US9810310B2 (en) | 2014-04-07 | 2017-11-07 | Eaton Corporation | Multi-component fluid distribution system |
| US9452840B2 (en) * | 2014-04-15 | 2016-09-27 | The Boeing Company | Monolithic part and method of forming the monolithic part |
| CN112524343B (en) * | 2020-10-28 | 2023-04-07 | 安徽杰蓝特新材料有限公司 | Reinforced wear-resistant PE gas pipe for trenchless construction and preparation method thereof |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB690491A (en) * | 1950-03-13 | 1953-04-22 | Ici Ltd | Apparatus suitable for the centrifugal moulding of tubes and tube liners from thermoplastic materials |
| US3258512A (en) * | 1963-05-09 | 1966-06-28 | Archibald T Flower | Method of applying a rigid unicellular polyurethane foam coating to pipe fittings |
| US3394207A (en) * | 1963-06-14 | 1968-07-23 | Andersen Ege | Method of casting foam insulation for an elongated member |
| US3426110A (en) * | 1965-03-26 | 1969-02-04 | Gen Motors Corp | Refrigerating apparatus |
| GB1104659A (en) * | 1965-09-13 | 1968-02-28 | Ici Ltd | Manufacture of cellular reinforced articles |
| US3359351A (en) * | 1965-10-18 | 1967-12-19 | Richard B Bender | Method of applying insulation coating for pipe |
| DE1629609A1 (en) * | 1966-05-18 | 1971-01-28 | Ruetgerswerke Ag | Process for the production of insulated pipes and pipe parts from plastics |
| JPS4818581B1 (en) * | 1969-08-11 | 1973-06-07 | ||
| DE2529001A1 (en) * | 1975-06-28 | 1977-01-13 | Alfred Boeckmann | SOLAR ENERGY CONVERTER WITH STORAGE FOR THE CONVERTED ENERGY |
| US4049480A (en) * | 1975-10-10 | 1977-09-20 | Nipak, Inc. | Method and apparatus for forming a joint in a confined space between two abutting ends of conduit liners |
| US4009732A (en) * | 1976-03-01 | 1977-03-01 | Martin Luther W | Methods of sealing annular space between inner and outer gas mains for tie-overs |
| SE414532B (en) * | 1979-06-18 | 1980-08-04 | Blom H | DEVICE BY A REMOTE CONDUCT AND WAY TO MAKE SUCH A DEVICE |
| US4276245A (en) * | 1979-08-22 | 1981-06-30 | Owens-Corning Fiberglas Corporation | Method of making and using molds for longitudinally curved sections of pipe insulation |
| FR2479945A1 (en) * | 1980-04-03 | 1981-10-09 | Brangues Chaudronnerie Tuyaute | PROCESS FOR THE CALORIFUGEAGE OF CONDUITS AND DUCTS OBTAINED |
-
1982
- 1982-02-23 SE SE8201114A patent/SE434815B/en not_active IP Right Cessation
-
1983
- 1983-02-15 DK DK64783A patent/DK64783A/en not_active Application Discontinuation
- 1983-02-15 CH CH826/83A patent/CH662086A5/en not_active IP Right Cessation
- 1983-02-16 FR FR8302470A patent/FR2522112B1/en not_active Expired
- 1983-02-16 US US06/466,862 patent/US4485057A/en not_active Expired - Fee Related
- 1983-02-16 FI FI830521A patent/FI830521L/en not_active Application Discontinuation
- 1983-02-18 BE BE0/210154A patent/BE895954A/en not_active IP Right Cessation
- 1983-02-19 DE DE19833305808 patent/DE3305808A1/en not_active Withdrawn
- 1983-02-22 NL NL8300651A patent/NL8300651A/en not_active Application Discontinuation
- 1983-02-22 NO NO830609A patent/NO830609L/en unknown
- 1983-02-23 CA CA000422251A patent/CA1192716A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR2522112B1 (en) | 1986-12-26 |
| BE895954A (en) | 1983-06-16 |
| FR2522112A1 (en) | 1983-08-26 |
| NL8300651A (en) | 1983-09-16 |
| DE3305808A1 (en) | 1983-09-01 |
| DK64783D0 (en) | 1983-02-15 |
| NO830609L (en) | 1983-08-24 |
| FI830521A0 (en) | 1983-02-16 |
| SE8201114L (en) | 1983-08-24 |
| DK64783A (en) | 1983-08-24 |
| US4485057A (en) | 1984-11-27 |
| FI830521L (en) | 1983-08-24 |
| SE434815B (en) | 1984-08-20 |
| CH662086A5 (en) | 1987-09-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEC | Expiry (correction) | ||
| MKEX | Expiry |