Recherche Images Maps Play YouTube Actualités Gmail Drive Plus »
Connexion
Les utilisateurs de lecteurs d'écran peuvent cliquer sur ce lien pour activer le mode d'accessibilité. Celui-ci propose les mêmes fonctionnalités principales, mais il est optimisé pour votre lecteur d'écran.

Brevets

  1. Recherche avancée dans les brevets
Numéro de publicationUS3925165 A
Type de publicationOctroi
Date de publication9 déc. 1975
Date de dépôt13 août 1973
Date de priorité18 août 1972
Autre référence de publicationDE2341180A1, DE2341180B2
Numéro de publicationUS 3925165 A, US 3925165A, US-A-3925165, US3925165 A, US3925165A
InventeursHans Muller
Cessionnaire d'origineMueller Hans
Exporter la citationBiBTeX, EndNote, RefMan
Liens externes: USPTO, Cession USPTO, Espacenet
Apparatus for culturing of tissue cells and micro-organisms
US 3925165 A
Images(2)
Previous page
Next page
Description  (Le texte OCR peut contenir des erreurs.)

United States Patent 1191 Miiller Dec. 9, 1975 APPARATUS FOR CULTURING 0F TISSUE 3,767,535 10/1973 Havewala et al. .1 195/143 3,839,155 10/1974 McAleer et al 195/127 CELLS AND MICRO-ORGANISMS [76] inventor: Hans Miiller, lm Allmendli,

Erlenbach, Zurich, Switzerland 22 Filed: Aug. 13, 1973 [21] Appl. No.: 388,036

[30] Foreign Application Priority Data Aug. 18, 1972 Switzerland 12326/72 [52] US. Cl. 195/127; 195/142; 195/143 [51] Int. Cl. C12B 1/16 [58] Field of Search 195/127, 139, 142, 143

[56] References Cited UNITED STATES PATENTS 2,996,429 8/1961 Toulmin 195/142 Primary ExaminerAlvin E. Tanenholtz Attorney, Agent, or FirmMichael S. Striker [57] ABSTRACT A rotatable shaft is mounted in a housing and a plurality of culture carriers having exposed surfaces on which the respective cultures are to grow, is releasably connected with the support to extend radially from the same within the housing. A drive is provided for rotating the support or shaft.

11 Claims, 6 Drawing Figures 7 3 12 20 k/z L l .:;::::E L

US. Patent Dec. 9, 1975 Sheet 1 of2 3,925,165

F/GZZ U.S. Patent Dec. 9, 1975 Sheet 2 of2 3,925,165

FIG. 3B I APPARATUS FOR CULTURING OF TISSUE CELLS AND MICRO-ORGANISMS BACKGROUND OF THE INVENTION The present invention relates to an apparatus for culturing of tissue cells and micro-organisms in general, and more particularly to an apparatus of this type wherein the carriers on which the cultures are to be grown, can be rotated.

It is well known that in certain circumstances a free growth of cells must not be permitted in culture-growing arrangements, because this can lead to an undesired deterioration of the cell structure. For this reason the prior art has developed the concept of growing cells, which may for instance be isolated out of a tissue and intended for the manufacture of vaccines, on a rigid carrier having an exposed surface on which the cells form a monolayer. If large amounts of vaccines are to be produced, then large surface areas must be provided on which the cells are to grow, that is to be cultured. These surfaces areas must be uniformly contacted with nutrient medium and with certain gases, particularly with oxygen in order to pennit proper growth of the cells.

Apparatus of this type is already known in the art. Thus, it is known to provide an apparatus having a plurality of plates which are arranged one above the other and on which the culture medium is to be grown. It is also known to provide an apparatus having horizontal tubes which are mounted on vertical rotatable plates in order to facilitate the movement of liquid and gases. More recently an improved type of apparatus has been proposed, which is not only more effective but also smaller than those known from the previous art, wherein the carrier is configurated as a spiral element of synthetic plastic material, enamelled metal or glass. These materials have been found to be the most advantageous for the growth of cultures.

All of the prior-art constructions have advantages, but all of them are not entirely satisfactory in some respects. Thus, the type of apparatus having the vertically spaced horizontal plates presents problems with supplying the gas, because if gas is admitted below the level of liquid in the housing wherein the vertically spaced plates are located, foam will develop in the nu trient medium and this in turn disadvantageously influences the growth of the cell culture. The result of this is a denaturization of the very delicate proteins of the substrate and a non-uniform distribution of the gases into contact with different portions of the carrier surfaces. The constructions having a spiral carrier which can be rotated, provide a substantial improvement over this other prior-art construction, because during each rotation of the spiral carrier in a housing which is not entirely filled with liquid the horizontally arranged open inlet of the spiral tends to pump gas into the liquid which is entrapped between the individual turns of the spiral. In other words, in this construction gas and nutrient medium are regularly brought into contact with the cell cultures which grow on the surfaces of the spiral carrier. Air and/or other gases can be admitted into the spaces between the convolutions of the spiral carrier only once. Moreover, especially if cell cultures are to be grown on this carrier, only a very slow rotation of the carrier is permissible if uniform growth of the culture is desired. This means that if for instance only one or two rotations of the spiral carrier take place per hour, the exchange of air and/or other gas is very slow, that is the time periods which elapse between successive contacting of all portions of culture which grow on the surfaces of the spiral carrier with gas, is relatively long. Particularly if an apparatus of this type is relatively large, there is the further disadvantage that very long carriers of a spiral nature must be utilized. Assuming, for instance, that the apparatus is to have a spiral carrier which affords 30 square meters of culture-growing surface, then the spiral carrier must be in form of a strip-shaped member having a length of approximately 30 meters. Of course, depending upon the axial length of the spiral, the circumferential length of the strip may be shorter but in that case its width (its dimension in axial length of the spiral) will be greater. In any case, these spiral carriers are then very diffic ult to clean, and can in fact be cleaned (for subsequent removal of the tissue cells or micro-organisms when the particular culturing operation is completed) only with the aid of complicated and expensive auxiliary equipment. Even the use of granular cleaning aids, which are intended to scour the cells or micro-organisms off the surfaces of the spiral carrier when admitted into the housing while the spiral carrier is rotated at a fast speed, does not provide for a completely effective cleaning action.

SUMMARY OF THE INVENTION It is, accordingly, a general object of the present invention to overcome the disadvantages of the prior art.

More particularly, it is an object of the present invention to provide an improved apparatus for culturing of tissue cells and micro-organisms, which is not possessed of the aforementioned disadvantages.

Another object of the invention is to provide such an improved apparatus which affords the advantages of the type of apparatus outlined earlier and having a spiral carrier, but which provides for a better gas exchange per unit of time.

Another object of the invention is to provide such an improved apparatus which facilitates greatly the cleaning of the culture carriers.

Another object of the invention is to provide an apparatus of the type in question, wherein the cleaning of the culture carriers with the aid of granular cleaning aids is particularly facilitated.

Still an additional object of the invention is to provide such an improved apparatus wherein the inspection of the culture carriers, which is necessary from time to time, is made much simpler than heretofore.

In keeping with these objects, and with others which will become apparent hereafter, one feature of the invention resides in an apparatus for culturing of tissue cells and micro-organisms which, briefly stated, comprises a housing, a rotatable support mounted in the housing, and a plurality of culture carriers having exposed surfaces on which the respective cultures are to grow. Connecting means releasably connects the carriers with the support, and drive means serve to rotate the support.

Such an apparatus avoids the disadvantages of the prior art and meets all of the requirements made of it, as outlined above.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages 3 thereof, will be best understood from the following description of specific embodiments when read in connection with the accompaning drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a somewhat diagrammatic axial section through an apparatus according to the present invention;

FIG. 2 is a section taken on line Il-II of FIG. 1;

FIG. 3A is a plan view of one of the culture carriers in the apparatus of FIGS. 1 and 2;

FIG. 3B is an end view of the carrier in FIG. 3A, looking towards the right in that Figure;

FIG. 4 is a fragmentary section illustrating further details of the invention; and

FIG. 5 is a fragmentary detail view, illustrating another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now firstly to FIGS. 1-3 it will be seen that the apparatus according to the present invention utilizes a cylindrical housing which in the illustrated embodiment is constituted by a cylinder 9 of glass or synthetic plastic material. At the opposite ends of the cylinder 9 there are provided two end covers I l which are mounted on the cylinder 9 by means of longitudinally extending rods 10, onto free threaded ends of which there are threaded the illustrated nuts, so that the covers l I are pressed against the opposite open ends of the cylinder 9. The inwardly directed sides of the covers 1 I are provided with annular grooves in which sealing material may be located as illustrated, so that the opposite ends of the cylinder 9 extend into these grooves and engage the sealing material, whereby the housing is sealed.

A support is provided in form of a hollow shaft 4 which extends axially through the housing and on which there are provided two axially spaced annuli of projections 17. Successive ones of the projections 17, that is circumferentially successive ones of them, define with one another narrow grooves or spaces. The carriers for the culture to be grown are identified with reference numeral 1 and their inner longitudinal edges, that is those closest to the shaft 4, are received in these gaps or grooves. The insertion can be made axially or radially with respect to the shaft 4.

Each of the carriers I has two axially spaced ends, and adjacent the respective ends of the set of carriers 1 there are located end plates 19. In the illustrated embodiment there is interposed a sealing member 7 (here of disc-shaped configuration) between the respective end plate 19 and the juxtaposed ends of the carriers 1. The carriers 1 will, incidentally, be seen to be circumferentially distributed about the periphery of the shaft 4 (see FIG. 2) and to be curved in the circumferential direction of the shaft 4. At the left-hand side of FIG. I the end plate 19 abuts a shoulder of the shaft 4, and at the right-hand end the end plate 19 is held in place by a nut 20 which is threaded onto threads provided for this purpose on the shaft 4. Thus, the end plates 19 are pressed against the opposite axial ends of the carriers 1, holding the latter in position so that they cannot slip out of the respective grooves (note the axially extending annular flange on the outer periphery of each of the end plates 19).

It is particularly clear from FIG. I that the inner edges of the carriers I are not directly in contact with 4 the periphery of the shaft 4, but are slightly spaced from the same so that together they form an annular clearance C about the periphery of the shaft 4 (see FIG. 1), which clearance C of course communicates with the spaces between the circumferentially adjacent carriers 1. The end plates 19 are each provided with apertures 3 which communicate with the clearance C and which also communicate with the interior of the hous- The shaft 4 communicates via an inlet 12 with a source of heat exchange fluid (for heating or cooling purposes) which circulates through the shaft 4 and leaves the latter through the outlet 12'. The shaft 4 is journalled at the left-hand end of FIG. I in an appropriate journal formed in one of the plates 11, and at the right-hand end in a seal 5 (of the type that can be maintained sterile, and which is well known from the art) through which it extends to the exterior of the housing. Inlets 6 are provided for the admission of air and/or other gas into the interior of the housing, and a port 8 is provided through which nutrient medium can be admitted and through which it can also be discharged.

The spacing in circumferential direction between circumferentially adjacent ones of the curved carriers 1 (they need of course not be curved) is identified with reference numeral 2 (see FIG. 2) and each of the carriers I is provided with at least one abutment 18 which in the illustrated embodiment is formed adjacent the radially outer edge of the respective carrier 1 and which abuts a circumferentially successive one of the carriers 1. This means that the spacing in circumferential direction between the carriers 1, that is the dimension of the space 2, is precisely fixed. The components 4, l, 19 and 7 in effect constitute a rotatable drum which is located in the interior of the housing. This drum is a structural unit, not the least due to the fact that the axially extending annular flanges at the outer peripheries of the plates 19 hold the carriers 1 in place.

In operation of the apparatus thus far described, nutrient medium is admitted through the port 8 until it completely covers the shaft 4 so that the uppermost ones of the carriers 1 still extend out of the nutrient medium. At this time the drive composed of an electromotor 13, as well as drive belt 16 and the associated drive pulleys l4 and 15, is energized so that the shaft 4 begins to rotate very slowly, in the illustrated embodiment in clockwise direction. Clockwise direction is assumed because in this embodiment the carriers 1 are curved in circumferential direction, and in particular in clockwise direction. During such rotation in clockwise direction the successive curved carriers 1 enter out of the upper space of the housing, which is not filled with nutrient medium, into the nutrient medium which is accommodated in the housing in the lower space thereof. During each such entry a bubble of gas or air is entrapped between two successive ones of the entering carriers 1, and during the slow rotation this gas or air can contact all parts of the facing surfaces of the neighboring or successive carriers 1. In fact, the bubble continues to do so until the carriers 1 between which it is trapped reach the lowest point in the housing at which time the bubble can escape through one of the openings 3 into the ambient nutrient medium in the housing. During the further rotation in an ascending sense the space between the two circumferentially successive carriers 1 is now completely filled with nutrient medium which is replaced with new air or gas only after these same carriers emerge again out of the nutrient medium contents of the housing into the upper part of the housing which is not filled with the nutrient medium. At that time air or gas can again enter between them whereas the nutrient medium which heretofore was entrapped between them run off through the gap C and the openings 3 back into the main body of nutrient medium in the housing.

In FIGS. 3A and 3B I have illustrated one of the carriers 1, in plan view and in end view, respectively. It will be seen how each of the carriers -1 is curved, without requiring a detailed description.

FIG. 4 shows on an enlarged scale how the carriers 1 are mounted there on the shaft 4, except that in this embodiment the projections 17 are replaced with grooves 170 which are formed in the outer periphery of the carrier 4 and extend in axial parallelism with the axis of rotation of the same. FIG. 4 additionally shows that in place of the curved carriers 1, or in addition to them it is also possible to provide planar carriers la which can again be secured to the carrier 4 by means of the grooves 17a or as in FIGS. 1-3, by means of the projections 17.

FIG. 5, finally, illustrates an additional embodiment of the invention which shows that the shaft 4 can also be provided with more than one type of connecting means. In particular, I have illustrated the projections 17 which were described with respect to FIGS. 1-3. It is also possible, however, to provide the grooves 170 (shown in FIG. 4, but not in FIG. 5) or the pin-shaped projections 21 which are shown in FIG. 5. The inner edges of the carriers 1 or In would be received between circumferentially adjacent ones of the projections 21, just as they can be received between circumferentially adjacent ones of the projections 17. Again, all three types of connecting means can be provided on one and the same shaft 4, if desired.

Needless to say, further possibilities for releasable connecting means will offer themselves readily to those skilled in the art, for instance projections formed on the inner edges of the carriers 1 and which extend into appropriately shaped recesses or holes in the periphery of the shaft 4, or similar projections on the shaft 4 which extend into recesses or holes in the inner edges of the carriers 1.

It will be clear from what has been set forth above that the apparatus according to the present invention meets all requirements made of it, as set forth in the introductory portions of this specification, and that it overcomes the disadvantages outlined with respect to the prior art. Moreover, the novel apparatus has further advantages, particularly with reference to the type of apparatus of the prior art which uses a spiral carrier, especially in terms of a simple and economically advantageous manufacture of such an apparatus. Because the individual carriers 1, if they are curved, are all of the same curvature, only a single apparatus is required for producing them if they are made of synthetic plastic or metal. If, on the other hand, a spiral carrier according to the prior art is to be produced of several pieces, then the radii of curvature necessarily increase in radially outward direction of the spiral so that separate apparatus is required for producing the separate parts of which the carrier is to be assembled.

More important than considerations of ease and economy of manufacture, however, is the fact that the apparatus according to the present invention assures that even during a slow rotation of the shaft 4 sufficient gas will come in contact with a relatively small surface 6 area carrying the growing culture, so that a more perfect gas exchange (contact of gas and growing culture per unit time) is obtained. Also, the fact that the carriers 1 or 1a can be readily removed facilities greatly their inspection and cleaning or replacement. There are many countries, for instance, where it is required that when a job is completed with an apparatus of the type in question, the apparatus must be completely disassembled and cleaned, or where such a requirement is made after a certain number of production cycles has been completed. Evidently, this is very readily possible in the apparatus according to the present invention, because merely a removal of one of the plates 11 and one of the plates 19 will suffice to be able to withdraw the carriers 1 for inspection and cleaning.

Moreover, the rather simple shape of the carriers 1 or 1a makes it possible to make them not only of synthetic plastic material or of metal, but also of glass. This is a material which in many instances is vastly preferred over any other type of material for culture growing because it has been found to be highly advantageous for this purpose, especially for the growing of monolayer cultures.

It should be pointed out that if the carriers la are planar rather than curved, as is shown in FIG. 4, the container must not be filled with nutrient medium to quite the extent discussed earlier, to assure that air can be properly entrapped between successive ones of the carriers 1a as they dip into and become immersed in the nutrient medium. The construction of planar carriers 10 is of course particularly simple and inexpensive, especially if they are to be made of glass. An apparatus according to the present invention can have a very large composite surface area on which to grow tissue cell cultures or micro-organisms, because more than one of the shafts 4 with the associated carriers 1 and other components can be accommodated in a single housing, or the housing can be made long enough and either the carriers 1 or 10 can be made very long or a plurality of sets of carriers 1 or In can be provided on the shafts 4 and at axially spaced locations thereof.

It will be understood that each of the elements described above, or two or more together. may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in an apparatus for culturing of tissue cells and micro-organisms, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended:

1. In an apparatus for culturing of tissue cells and micro-organisms, a combination comprising a housing; a support mounted in said housing for rotation about an axis; drive means for rotating said support about said axis; a plurality of elongated culture carriers circumferentially spaced from each other about the periphery of said support and each elongated in a direction parallel to said axis and partly bounding with an adjacent carrier a space that is elongated lengthwise of said axis, and having exposed surfaces on which respective cultures are to grow, and longitudinally spaced ends; connecting means for releasably connecting said carriers with said support; and a pair of end plates located at the respective ends of said carriers.

2. In an apparatus for culturing of tissue cells and micro-organisms, a combination comprising a housing; a support mounted in said housing for rotation about an axis; drive means for rotating said support about said axis; a plurality of elongated culture carriers circumferentially spaced from each other about the periphery of said support and each extending in a direction parallel to said axis and having exposed surfaces on which the respective cultures are to grow, and longitudinally spaced ends; connecting means for releasably connecting said carriers with said support and including first connecting portions on said support, and cooperating second connecting portions on said carriers and engaging said first connecting portions; and a pair of end plates located at and interposed between the respective ends of said carriers and the interior of said housing and holding said carriers in their respective positions relative to said support.

3. in an apparatus for culturing of tissue cells and micro-organisms, a combination comprising a housing; a support element mounted in said housing for rotation about an axis; drive means for rotating said support element about said axis; a plurality of elongated culture carrier elements circumferentially spaced from each other about the periphery of said support and each extending in a direction parallel to said axis and having exposed surfaces on which the respective cultures are to grow, and longitudinally spaced ends; connecting means for releasably connecting said carrier elements with said support element and including grooves on one of said elements and extending along said axis, and engaging portions on the other of said elements and received in the respective grooves; and a pair of end plates located at and interposed between the respective ends of said carrier elements and the interior of said housing and holding said carrier elements in their respective positions relative to said support elements.

4. A combination as defined in claim 1, wherein said carriers are strip-shaped; and wherein said connecting 8 means comprises grooves formed in said support in substantial parallelism with the axis of rotation of the same, said carriers being partly received in respective ones of said grooves and projecting from the same in direction radially of said axis of rotation.

5. A combination as defined in claim 1, wherein said connecting means comprises projections provided on said support and extending in substantial parallelism with the axis of rotation of the same, said projections being spaced circumferentially of said axis; and wherein said carriers each have a portion received between two circumferentially successive ones of said projections.

6. A combination as defined in claim 1, wherein said support has grooves which extend in substantial parallelism with its axis of rotation; and wherein said carriers are of curved strip-shaped configuration and each have a marginal portion received in one of said grooves.

7. A combination as defined in claim 1, wherein said connecting means comprises projections on said support, extending in substantial parallelism with the axis of rotation of the same and being spaced circumferentially of said axis; and wherein said carriers are of curved strip-shaped configuration and each have a portion received between two circumfere ntially successive ones of said projections.

8. A combination as defined in claim 1, said carriers each having an edge face adjacent to but slightly spaced from said periphery, so that all of said edge faces define about said periphery an annular gap which is in communication with the spaces between periphen ally adjacent ones of said carriers.

9. A combination as defined in claim 8, wherein said endplates are provided with apertures which communicate with said annular gap.

10. A combination as defined in claim 1, said carriers each having an inner edge adjacent to, and an outer edge radially outwardly spaced from said support; and,

further comprising at least one abutment portion on each of said carriers intermediate said edges thereof, each abutment portion being in abutment with a circumferentially adjacent carrier so as to fix the circumferential distance between the carriers.

11. A combination as defined in claim 10, wherein said abutment portions are provided in the region of the respective outer edges.

0 i I I

Citations de brevets
Brevet cité Date de dépôt Date de publication Déposant Titre
US2996429 *12 févr. 195915 août 1961Nat Toxicological Lab IncMethod and apparatus for growing living tissue
US3767535 *14 juin 197123 oct. 1973Corning Glass WorksMethod of reacting an insolubilized enzyme in a fluid medium
US3839155 *27 juil. 19721 oct. 1974Merck & Co IncCell and vaccine production
Référencé par
Brevet citant Date de dépôt Date de publication Déposant Titre
US4228242 *16 août 197814 oct. 1980Chemap AgArrangement for cultivating cells of animal and human tissues
US4310630 *13 mars 198012 janv. 1982Chemap AgArrangement for cultivating cells of animal and human tissues
US4339537 *6 nov. 197913 juil. 1982Olympus Optical Company LimitedMethod of culturing biological substances
US4376826 *17 juin 198015 mars 1983Mynatt Roy LContinuous production of bacteria for leaching of metallic ore
US4379846 *27 avr. 198112 avr. 1983Shkidchenko Alexandr NFermentation apparatus
US4535062 *7 févr. 198313 août 1985Chemap AgApparatus for growing microorganisms
US5026650 *30 juin 198825 juin 1991The United States Of Amercia As Represented By The Administrator Of The National Aeronautics And Space AdministrationHorizontally rotated cell culture system with a coaxial tubular oxygenator
US5081035 *11 févr. 199114 janv. 1992The University Of MichiganBioreactor system
US5316945 *14 déc. 199231 mai 1994Will MinuthCell carrier arrangement
US5403742 *1 sept. 19934 avr. 1995Ramot University Authority Ltd.Bioreactor for production of products with immobilized biofilm
US5427948 *29 juil. 199327 juin 1995Michigan State UniversityApparatus for conducting hybridization
US5432087 *28 nov. 199111 juil. 1995Spielmann; RichardApparatus having rotatable planar trays for culturing microorganisms
US5437998 *9 sept. 19931 août 1995Synthecon, Inc.Gas permeable bioreactor and method of use
US5439823 *25 févr. 19948 août 1995Martial Plant CorporationApparatus for fast fermentation treatment
US5650325 *7 juin 199522 juil. 1997Spielmann; RichardApparatus having a rotatable stack of parallel trays with culturing surfaces on opposite sides for liquid/gas exchange
US6001642 *29 juin 199814 déc. 1999Wyle Laboratories, Inc. Life SciencesBioreactor and cell culturing processes using the bioreactor
US719894025 oct. 20013 avr. 2007Shot Hardware Optimization Technology, Inc.Bioreactor apparatus and cell culturing system
US20100015696 *12 mai 200721 janv. 2010Tom ClaesDisposable bioreactor
DE3544382A1 *14 déc. 198519 juin 1987Ivan Prof Dr Ing SekoulovVerfahren zur sauerstoffversorgung von bioreaktoren und vorrichtung zur durchfuehrung des verfahrens und die anwendung der vorrichtung
Classifications
Classification aux États-Unis435/299.1
Classification internationaleC12M3/04, C12M1/14
Classification coopérativeC12M27/14, C12M25/06
Classification européenneC12M25/06, C12M27/14
Événements juridiques
DateCodeÉvénementDescription
29 mars 1983AS02Assignment of assignor's interest
Owner name: CHEMAP AG
Owner name: MULLER, HANS
Effective date: 19830318
29 mars 1983ASAssignment
Owner name: CHEMAP AG
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:MULLER, HANS;REEL/FRAME:004117/0791
Effective date: 19830318