Processes Patents (Class 564/314)
  • Patent number: 9196840
    Abstract: Novel fluoroacyl arylamines useful in organic electronic applications are disclosed, including methods of synthesizing those fluoroacyl arylamines using Lewis acids for acyl moiety activation.
    Type: Grant
    Filed: November 21, 2012
    Date of Patent: November 24, 2015
    Assignee: Xerox Corporation
    Inventors: Adrien P Cote, Richard A Klenkler, Amanda L Bongers, Gregory M McGuire
  • Publication number: 20140275558
    Abstract: This document is related to the field of preparation of haloalkoxyarylhydrazines and certain intermediates derived therefrom, where said intermediates are useful in the preparation of certain pesticides disclosed in U.S. Pat. No. 8,178,658.
    Type: Application
    Filed: February 27, 2014
    Publication date: September 18, 2014
    Applicant: Dow AgroSciences LLC
    Inventors: Ronald ROSS, JR., Peter BORROMEO
  • Publication number: 20140275561
    Abstract: The invention in this document is related to the field of preparation of haloalkoxyarylhydrazines and certain intermediates derived therefrom, where said intermediates are useful in the preparation of certain pesticides disclosed in U.S. Pat. No. 8,178,658.
    Type: Application
    Filed: February 27, 2014
    Publication date: September 18, 2014
    Applicant: Dow AgroSciences LLC
    Inventors: Ronald ROSS, JR., Gary ROTH
  • Patent number: 8754260
    Abstract: A method for making fluoroacyl arylamines is disclosed.
    Type: Grant
    Filed: November 21, 2012
    Date of Patent: June 17, 2014
    Assignee: Xerox Corporation
    Inventors: Adrien P Cote, Amanda L Bongers
  • Patent number: 8629301
    Abstract: The present invention relates to the economical and separation of benzphetamine hydrochloride and methamphetamine by liquid extraction. An extraction process employing a suitable organic solvent and water at a pH in the range of from about 6 to about 8 provides excellent removal of the methamphetamine by dissolution in the water phase while the benzphetamine dissolves in the organic phase. Simple separation of the two phases results in separation of the two amines.
    Type: Grant
    Filed: November 2, 2005
    Date of Patent: January 14, 2014
    Assignee: Mallinckrodt LLC
    Inventor: Keith G. Tomazi
  • Publication number: 20110313171
    Abstract: The present invention relates to the preparation of aryl hydrazines and their salts by treating aryl diazonium salts with triphenyl phosphine followed by hydrolysis of the resulting triphenyl-aryl hydrazyl phosphonium salt to get aryl hydrazine or its salt.
    Type: Application
    Filed: January 12, 2007
    Publication date: December 22, 2011
    Inventors: Chandra Purna Ray, Sreekanth Medikonduri, Gorantla Seeta Ramanjaneyulu
  • Publication number: 20110031430
    Abstract: Novel water soluble paramagnetic organic nanoparticles are formed by a novel method where an organic solution of an organic compound is injected into water under agitation that is maintained for a desired period of time for nanoparticle growth followed by termination of the growth by the addition of an aqueous surfactant solution. The size of the nanoparticles depends on the time between injection and addition of the surfactant solution. In embodiments of the invention, the water soluble paramagnetic organic nanoparticles can be DPPH nanoparticles, DPPH nanoparticles doped with DPPH-H, or core/shell nanoparticles where a DPPH core is covered by a DPPH-H shell.
    Type: Application
    Filed: August 4, 2010
    Publication date: February 10, 2011
    Applicant: UNIVERSITY OF FLORIDA RESEARCH FOUNDATION INC.
    Inventors: Y. CHARLES CAO, Ou Chen, Alexander Angerhofer
  • Publication number: 20100096585
    Abstract: This invention relates to a process for preparing 2,6-dichloro-4-(trifluoromethyl)phenylhydrazine of the formula (I) wherein a mixture comprising 1,3-dichloro-2-fluoro-5-trifluoromethylbenzene and 1,2-dichloro-3-fluoro-5-trifluoromethylbenzene is reacted with a hydrazine source selected from hydrazine, hydrazine hydrate or acid addition salts of hydrazine, optionally in the presence of at least one organic solvent.
    Type: Application
    Filed: February 27, 2008
    Publication date: April 22, 2010
    Applicant: BASF SE
    Inventors: Thomas Zierke, Michael Rack
  • Publication number: 20100010263
    Abstract: This invention relates to a process for preparing substituted phenylhydrazines of the formula I wherein R has the meaning as indicated in the description, comprising reacting a dichlorofluorobenzene of the formula II with a hydrazine source selected from hydrazine, hydrazine hydrate and acid addition salts of hydrazine and optionally being carried out in the presence of at least one organic solvent.
    Type: Application
    Filed: February 27, 2008
    Publication date: January 14, 2010
    Applicant: BASF SE
    Inventors: Thomas Zierke, Michael Rack
  • Publication number: 20080306302
    Abstract: A process for the preparation of organic cation tetrakis(Faryl) borate salts. The process includes preparation of intermediate, mono-hydrazine substituted (Faryl) compound, from (Faryl) compound using hydrazine at temperatures below 78° C. A stoichiometric excess of hydrazine to the (Faryl) compound to the (Faryl) compound is used. The process further includes the preparation of the organic cation tetrakis(Faryl) borate in ethereal medium.
    Type: Application
    Filed: December 8, 2006
    Publication date: December 11, 2008
    Inventor: Bruce C. Berris
  • Patent number: 7390929
    Abstract: The invention relates to a method for the continuous synthesis of monoalkyl-hydrazines with a functionalized alkyl group. The inventive method is characterized in that it comprises a step consisting in demixing a solution containing the synthesized monoalkyl-hydrazine, by reacting an anhydrous amine with monochloramine, in an organic phase and an aqueous phase with the addition of anhydrous sodium hydroxide. The invention can be used to obtain perfect selectivity in relation to monoalkyl-hydrazine without the presence of the di- and tri-substituted forms thereof. According to the invention, the staffing amine which has not reacted is collected and reused directly without any additional treatment.
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: June 24, 2008
    Assignees: Isochem, Centre National de la Recherche Scientifique (CNRS), Universite Claude Bernard Lyon 1
    Inventors: Henri Delalu, Cécile Colas-Duriche, Jacques Berthet, Philippe Leurent
  • Patent number: 7138548
    Abstract: A process for the preparation of a compound of formula (I): wherein Ar represents an optionally substituted aromatic carbocycle or heterocycle, and R1 and R2 independently represent hydrogen, C1-10 alkyl, C(O)C1-10 alkyl or optionally substituted aryl provided that R1 and R2 are not both hydrogen which process comprises reacting together a compound of formula (II): Ar—X??(II) wherein Ar is as defined in relation to formula (I) and X represents a leaving group with a a compound of formula (III) wherein R1 and R2 are as defined in relation to formula (I) under aqueous conditions in the presence of a Pd (II) salt, a ligand and a Group I or Group II metal hydroxide base at a pH greater than 7. Compounds of formula (I) may be hydrolysed to the corresponding hydrazine.
    Type: Grant
    Filed: October 2, 2002
    Date of Patent: November 21, 2006
    Assignee: Avecia Limited
    Inventors: Andrew John Blacker, David Dodman, David Anthony Jackson, Jan Michael Fielden, John Heathcote Atherton
  • Patent number: 6852890
    Abstract: A process for the preparation of a phenylhydrazine or an inorganic acid salt thereof of the formula (1): wherein X is a hydrogen or halogen atom; Y is a halogen atom; and W is a hydrogen atom or —ZR in which Z is an oxygen or sulfur atom, and R is a hydrogen atom, an alkyl group, a haloalkyl group, and so on, by the hydrolysis of a phenylhydrazine derivative of the formula (2): where X, Y and W are the same as defined above, and the Q groups are a hydrogen atom, an ammonium group or an alkali metal atom in the presence of water and an inorganic acid, in which the concentration of the inorganic acid is at least 6 moles per 1 kg of water in a reaction system.
    Type: Grant
    Filed: March 3, 2000
    Date of Patent: February 8, 2005
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Kazuyuki Tanaka, Yoshiaki Oda
  • Patent number: 6720428
    Abstract: According to a novel process, microbicidally active 2-(1,2,4-triazol-1-yl)-ethanols of the formula in which A1, A2, R1, R2, R3 and R4 are as defined in the description, can be prepared by reacting hydrazine derivatives of the formula with N-dihalogenomethyl-formamidinium halide of the formula in which X represents chlorine or bromine, if appropriate in the presence of a diluent.
    Type: Grant
    Filed: August 6, 2002
    Date of Patent: April 13, 2004
    Assignee: Bayer Aktiengesellschaft
    Inventor: Thomas Himmler
  • Patent number: 6706895
    Abstract: Disclosed herein is a compound having the formula: wherein R1 is alkyl and R2 and R3 are independently selected aryl groups. Also disclosed is a method of making bifenazate using the compound as an intermediate.
    Type: Grant
    Filed: November 14, 2002
    Date of Patent: March 16, 2004
    Assignees: Uniroyal Chemical Company, Inc., Crompton Co./Cie
    Inventors: Sheldon B. Park, Gaik-Lean Chee, Mark A. Dekeyser
  • Patent number: 6509503
    Abstract: The invention relates to processes for the preparation of compounds of formula (I) wherein R1 and R2 each independently represent a halogen atom.
    Type: Grant
    Filed: May 3, 2002
    Date of Patent: January 21, 2003
    Assignee: Aventis Cropscience S.A.
    Inventors: Jean-Erick Angel, Gilles Perrin-Janet, Pierre Leroy
  • Patent number: 6489512
    Abstract: A method for making an indole compound includes transition metal-catalyzed arylation of a hydrazone to form an aryl hydrazone, hydrolysis of the aryl hydrazone to form an aryl hydrazine, and acid catalyzed cyclization of the aryl hydrazine to form the indole compound.
    Type: Grant
    Filed: June 21, 2002
    Date of Patent: December 3, 2002
    Assignee: Rhodia Chirex Inc.
    Inventors: Frederick Hicks, Da-Ming Gou, Salvatore Anthony Marchese, Lawrence J. Martel, Atena Necula, Richard E. Benetti, Richard A. Silva
  • Publication number: 20020115880
    Abstract: A process for preparing 4-substituted 2-alkylbiphenyls and 2-alkoxybiphenyls of the formula (I), 1
    Type: Application
    Filed: February 11, 2002
    Publication date: August 22, 2002
    Applicant: Clariant GmbH
    Inventors: Andreas Meudt, Stefan Scherer, Frank Vollmuller, Heinz Georg Kautz
  • Publication number: 20020082274
    Abstract: This invention relates to methods of preparing sodium-hydrogen exchanger type 1 (NHE-1) inhibitors of formula I′ 1
    Type: Application
    Filed: November 27, 2001
    Publication date: June 27, 2002
    Inventors: John F. Lambert, Timothy Norris
  • Patent number: 6278022
    Abstract: Disclosed herein is an improvement in a method for making compounds having the structural formulae (I) or (II): wherein: X is a) phenyl; lower phenylalkoxy; phenoxy; or benzyl; or b) one substituent from group a) and one or more substituents selected from C1-C4 alkoxy; hydroxyl; halogen; lower alkyl; and lower alkylthio; or c) along with the phenyl to which it is attached, forms a multiple fused ring heterocycle such as dibenzofuranyl; Y is H, C1-C4 alkanoyl, C1-C4 haloalkenoyl, dialkoxyphosphoryl, alkylaminocarbonyl, haloalkylsulfonyl, or C1-C4 alkoxy carbonyl; and R is H, C1-C6 alkyl, C1-C6 alkoxy, C3-C6 cycloalkoxy, haloalkyl, alkoxyalkyl, arylalkoxy, alkenyl, alkylthio, alkoxycarbonyl, alkylamino, heteroaryl, arylalkyl, haloalkoxy, aryloxy, or C3-C6 cycloalkyl; and Z is O or S, wherein the improvement comprises the steps of: A) selecting as a starting material a compound of the structural formula B) dissolving compound III in an organic solvent selected from the group
    Type: Grant
    Filed: November 1, 1999
    Date of Patent: August 21, 2001
    Assignee: CK Witco Corporation
    Inventor: Haihong Jin
  • Patent number: 6166243
    Abstract: Disclosed herein is a method for making compounds having the structural formulae (I) or (II): ##STR1## wherein: X is a) phenyl; lower phenylalkoxy; phenoxy; or benzyl; or b) one substituent from group a) and one or more substituents selected from C.sub.1 -C.sub.4 alkoxy; hydroxyl; halogen; lower alkyl; and lower alkylthio; or c) along with the phenyl to which it is attached, forms a multiple fused ring heterocycle such as dibenzofuranyl; Y is H, C.sub.1 -C.sub.4 alkanoyl, C.sub.1 -C.sub.4 haloalkanoyl dialkoxyphosphoryl, alkylaminocarbonyl, haloalkylsulfonyl, or C.sub.1 -C.sub.4 alkoxy carbonyl; and R is H, C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 alkoxy, C.sub.3 -C.sub.6 cycloalkoxy, haloalkyl, alkoxyalkyl, arylalkoxy, alkenyl, alkylthio, alkoxycarbonyl, alkylamino, heteroaryl, arylalkyl, haloalkoxy, aryloxy, or C.sub.3 -C.sub.
    Type: Grant
    Filed: November 1, 1999
    Date of Patent: December 26, 2000
    Assignee: CK Witco Corporation
    Inventors: Haihong Jin, Joseph A. Feiccabrino
  • Patent number: 6087534
    Abstract: The invention involves a procedure for synthesizing aryl hydrazine through reduction of a diazo derivative. The distinguishing feature of the method is that it involves at least the following step: c) bringing a diazo derivative into contact with a sulphite solution in which the pH level is at least 7. Applications: organic synthesis.
    Type: Grant
    Filed: September 21, 1998
    Date of Patent: July 11, 2000
    Assignee: Rhodia Chimie
    Inventors: Jean-Manuel Mas, Christophe Rochin
  • Patent number: 6057478
    Abstract: The present invention relates to a process for preparing arylhydrazines of the formula R.sup.1 R.sup.2 R.sup.3 Ar--NH--NH.sub.2 (I) by reacting an arylhydrazinedisulfonate of the formula ##STR1## in which R.sup.1, R.sup.2, and R.sup.3 are identical or different and are H, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, halogen or OH, Ar is phenyl or naphthyl, M.sup.1 and M.sup.2 are identical or different and are H, NH.sub.4, an alkali metal or 1/2 alkaline earth metal and R.sup.1, R.sup.2, R.sup.3 and Ar in the formulae (I) and (II) have the same meaning, with water and an inorganic acid at from 0 to 100.degree. C. in the presence of an inert organic solvent to give the corresponding arylhydrazine salt and treating the arylhydrazine salt with a base.
    Type: Grant
    Filed: May 18, 1999
    Date of Patent: May 2, 2000
    Assignee: Clariant GmbH
    Inventors: Thomas Schach, Heinrich Volk, Manfred Koch
  • Patent number: 5599992
    Abstract: The invention relates to a process for the preparation of 2-fluorophenylhydrazine or 2-fluorophenylhydrazine hydrochloride, which comprises diazotizing 2-fluoroaniline, reducing the resulting diazonium salt with alkaline bisulfite solution to give 2-fluorophenylhydrazine .alpha..beta.-disulfonate, hydrolyzing the latter with hydrochloric acid to give 2-fluorophenylhydrazine hydrochloride, adding alkali metal solution to neutralize the mixture, subsequently cooling the mixture, removing the 2-fluorophenylhydrazine precipitate by filtration and, if appropriate, reacting the latter with hydrochloric acid to give 2-fluorophenylhydrazine hydrochloride.
    Type: Grant
    Filed: January 22, 1996
    Date of Patent: February 4, 1997
    Assignee: Hoechst Aktiengesellschaft
    Inventor: Otto Arndt
  • Patent number: 5585521
    Abstract: Alkylhydrazine salts are prepared on an industrial scale and with good results by reacting together hydrazine, an alkene and a strong protonic acid in the presence of water, hydrazine and the protonic acid being introduced, the alkene being added, the liquid and gaseous phases present in the reaction vessel being intensively mixed together at 75.degree. to 150.degree. C., then the reaction mixture being cooled to temperatures below 60.degree. C., the precipitated alkylhydrazine salt being separated off, hydrazine and strong protonic acid being again added to the mother liquor, then alkene being added again and the next reaction cycle being thus carried out.
    Type: Grant
    Filed: September 22, 1995
    Date of Patent: December 17, 1996
    Assignee: Bayer Aktiengesellschaft
    Inventors: Wolfram Eichinger, Helmut Fiege
  • Patent number: 5489711
    Abstract: An oligomer from diarylamines is disclosed which has desirable antioxidant properties in lubricating oils which contain synthetic ester lubricants. The oligomer is desirable for use at higher temperatures where it has less volatility than simple diarylamines. The oligomer has substantial portions of monosubstituted diphenylamine repeat units which result in linear oligomers. Di and polysubstituted diphenylamines may optionally be present as repeat units. These di and polysubstituted diphenylamines generally react as monofunctional reactants in oligomerization and tend to reduce the number of repeat units in the average oligomer.
    Type: Grant
    Filed: December 20, 1994
    Date of Patent: February 6, 1996
    Assignee: The B. F. Goodrich Company
    Inventor: John T. Lai
  • Patent number: 5387725
    Abstract: Compounds having acidic protons and a molecular structure which can delocalize the electron density of the conjugate base (target compounds) are chlorinated by contacting such compounds with a perchloroalkane and aqueous base in the presence of a phase transfer catalyst which is an tetraalkylammonium hydroxide. Chlorinated products, preferably gem-dichloro compounds, are produced. The gem-dichloro compounds are useful for alkylation of aromatic compounds. For instance fluorene is chlorinated to form 9,9-dichlorofluorene which is reacted with such compounds as phenol or aniline to form such compounds as 9,9-bis(hydroxyphenyl)fluorene, 9,9-bis(aminophenyl)fluorene, or 9-aminophenyl-9-chlorofluorene.
    Type: Grant
    Filed: July 12, 1993
    Date of Patent: February 7, 1995
    Assignee: The Dow Chemical Company
    Inventors: Marlin E. Walters, W. Frank Richey, Katherine S. Clement, Steven L. Brewster, Emmett L. Tasset, Paul M. Puckett, V. Rao Durvasula, Hong A. Nguyen
  • Patent number: 5041667
    Abstract: A process for producing a chlorohenylhydrazine compound is disclosed, which comprises chlorinating at least one hydrogen atom on the phenyl nucleus in a beta-imidated phenylhydrazine compound and subsequently hydrolyzing the chlorinated compound. Said chlorophenylhydrazine compound is useful as starting material for the production of herbicide, insecticide and photographic coupler is produced in high yield and low cost.
    Type: Grant
    Filed: June 26, 1986
    Date of Patent: August 20, 1991
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Mitsuto Fujiwhara, Tamotsu Kojima
  • Patent number: 5001262
    Abstract: This invention describes a method for synthesizing a polyhaloaromatic hydrazine compound, such as a tetra- or a penta- halophenylhydrazine. Such compounds are useful in the preparation of photographic color couplers.
    Type: Grant
    Filed: June 26, 1989
    Date of Patent: March 19, 1991
    Assignee: Eastman Kodak Company
    Inventor: Michael W. Crawley
  • Patent number: 4987258
    Abstract: The invention relates to 4,4'-diaminodiphenyl compounds of the formula I ##STR1## in which X denotes the n-propyl, isopropyl, n-butyl, isobutyl, 1-methylpropyl, n-propoxy, isopropoxy, isobutoxy, 1-methylpropoxy or 2-methoxyethoxy radical and A is 0 or the equivalent of an inorganic acid.The preparation is effected by reducing ortho-X-substituted nitrobenzene and benzidine rearrangement of the resulting hydrazobenzene derivative. The compounds of the formula (I) are suitable for use as components in the preparation of dyes and pigments.
    Type: Grant
    Filed: February 20, 1987
    Date of Patent: January 22, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Klaus Hunger, Heinrich Frolich, Kurt C. Habig
  • Patent number: 4864032
    Abstract: A process for the preparation of aryl hydrazines and indazoles by reacting organometallic regents with azodicarboxylates.
    Type: Grant
    Filed: July 2, 1987
    Date of Patent: September 5, 1989
    Assignee: Ortho Pharmaceutical Corporation
    Inventor: James P. Demers
  • Patent number: 4855501
    Abstract: Disclosed is a process for the preparation of monomethylhydrazine which comprises reacting hydrazine monohydrochloride with methanol in the presence of hydrazine dihydrochloride or methyl chloride and recovering free monomethylhydrazine from the formed monomethylhydrazine hydrochloride.According to this process, monomethylhydrazine can be prepared at a high selectivity very easily while controlling formation of by-products.
    Type: Grant
    Filed: December 3, 1981
    Date of Patent: August 8, 1989
    Assignee: Japan Hydrazine Co., Inc.
    Inventors: Shiro Hojo, Yoichi Hasegawa, Takeo Hirai
  • Patent number: 4772747
    Abstract: Disclosed is a process for the preparation of 2,4,6-trichlorophenylhydrazine by chlorinating the reaction product of phenylhydrazine and a dicarboxylic anhydride to obtain an N-(2,4,6-trichloroanilino)dicarboximide which is reacted with a base capable of liberating 2,4,6-trichlorophenylhydrazine therefrom.
    Type: Grant
    Filed: October 28, 1983
    Date of Patent: September 20, 1988
    Assignee: Eastman Kodak Company
    Inventors: Kevin J. Edgar, John A. Hyatt
  • Patent number: 4628119
    Abstract: A process for preparing hydrazine hydrohalogenide is disclosed.
    Type: Grant
    Filed: February 19, 1985
    Date of Patent: December 9, 1986
    Assignee: Mitsubishi Gas Chemical Co., Inc.
    Inventors: Takanari Nawata, Shuzabu Sakaguchi, Osamu Aoki
  • Patent number: 4574155
    Abstract: This invention provides a process for preparing a 2-hydrazino-1,3-diazacycloalk-2-ene hydrohalide. The process comprises reacting a one molar proportion of either tautomeric isomer of a 2-nitroamino-1,3-diazacycloalk-2-ene represented by the following formulas: ##STR1## wherein R.sup.1 is hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 hydroxyalkyl, C.sub.1 -C.sub.6 alkoxyalkyl, phenyl, substituted phenyl, benzyl, or substituted benzyl, R.sup.2 and R.sup.3 are independently hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 alkoxy, C.sub.1 -C.sub.6 alkoxyalkyl, hydroxyl, aryl, substituted aryl, aralkyl and substituted aralkyl, and n is an integer from 0 to 3 with about an equimolar proportion of an ammonium halide or hydrazonium halide, and about a 1 to 2 molar proportion of hydrazine hydrate in a composition selected from a C.sub.1 to C.sub.4 aliphatic alcohol, water or a mixture thereof, at a temperature from about ambient to the reflux, and isolating the end product as a monohydrohalide.
    Type: Grant
    Filed: March 8, 1984
    Date of Patent: March 4, 1986
    Assignee: American Cyanamid Company
    Inventor: Thurairajah Padmanathan
  • Patent number: 4564677
    Abstract: Disclosed is a method of preparing N-amino compounds from corresponding secondary amines by reacting a secondary amine with nitrous acid and zinc in a neutral pH reaction media to form the corresponding N-amine.
    Type: Grant
    Filed: January 19, 1984
    Date of Patent: January 14, 1986
    Assignee: USV Pharmaceutical Corp.
    Inventor: Martin L. Kantor
  • Patent number: 4352941
    Abstract: Crude phenylhydrazine is distilled in the presence of a glycol to obtain phenylhydrazine of high purity in a high yield.
    Type: Grant
    Filed: June 28, 1978
    Date of Patent: October 5, 1982
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Shinichi Hasegawa, Yuji Ueda, Hiroshige Tomita
  • Patent number: 4286108
    Abstract: A process is disclosed for preparing anhydrous hydrazines by reacting a tertiary hydrazinium halide with a corresponding alkali metal or alkaline earth metal amide in the presence of a non-aqueous inert carrier.
    Type: Grant
    Filed: October 17, 1979
    Date of Patent: August 25, 1981
    Inventor: Hans Osborg