Patents by Inventor Christa Liedtke

Christa Liedtke has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4444936
    Abstract: Novel bis-(silylethyl)-oligosulphides are obtained by reacting a vinyl silane of the formula (CH.sub.2 .dbd.CH).sub.m --SiR.sub.n.sup.1 R.sub.4--(m+n) in which R represents chlorine, bromine, iodine, C.sub.1 --C.sub.3 -alkoxy, 2-methoxyethoxy, 2-ethoxyethoxy or hydroxy, R.sup.1 represents C.sub.1 --C.sub.3 -alkyl, phenyl or C.sub.5 --C.sub.7 -cycloalkyl, n is 0, 1 or 2, m is 1 or 2 and m+n is 1, 2 or 3 with sulphur as well as in a given case hydrogen sulphide in molar ratios of vinyl silane to sulphur of from 1:2.5 to 1:10 and vinyl silane to hydrogen sulphide of from 1:0 to 1:5 at temperatures between about 100.degree. and 200.degree. C. under pressure of from 1 to 25 bars (total pressure at the reaction) temperature) and in the presence of sulphidation catalysts known per se, in a given case followed by hydrolysis or partial hydrolysis of the reaction products.
    Type: Grant
    Filed: January 27, 1983
    Date of Patent: April 24, 1984
    Assignee: Degussa Aktiengesellschaft
    Inventors: Rudolf Schwarz, Peter Kleinschmit, Christa Liedtke, Siegfried Wolff
  • Patent number: 4408064
    Abstract: Novel bis-(silylethyl)-oligosulphides are obtained by reacting a vinyl silane of the formula (CH.sub.2 .dbd.CH).sub.m -SiR.sub.n.sup.1 R.sub.4-(m+n) in which R represents chlorine, bromine, iodine, C.sub.1 -C.sub.3 -alkoxy, 2-methoxyethoxy, 2-ethoxyethoxy or hydroxy, R.sup.1 represents C.sub.1 -C.sub.3 -alkyl, phenyl or C.sub.5 -C.sub.7 -cycloalkyl, n is 0, 1 or 2, m is 1 or 2 and m+n is 1, 2 or 3 with sulphur as well as in a given case hydrogen sulphide in molar ratios of vinyl silane to sulphur of from 1:2.5 to 1:10 and vinyl silane to hydrogen sulphide of from 1:0 to 1:5 at temperatures between about 100.degree. and 200.degree. C. under pressure of from 1 to 25 bars (total pressure at the reaction temperature) and in the presence of sulphidation catalysts known per se, in a given case followed by hydrolysis or partial hydrolysis of the reaction products.
    Type: Grant
    Filed: December 26, 1979
    Date of Patent: October 4, 1983
    Assignee: Deutsche Gold- und Silber-Scheideanstalt Vormals Roessler
    Inventors: Rudolf Schwarz, Peter Kleinschmit, Christa Liedtke, Siegfried Wolff
  • Patent number: 4384132
    Abstract: Novel bis-(silylethyl)-oligosulphides are obtained by reacting a vinyl silane of the formula (CH.sub.2 .dbd.CH).sub.m -- SiR.sub.n.sup.1 R.sub.4 -(m+n) in which R represents chlorine, bromine, iodine, C.sub.1 -C.sub.3 -alkoxy, 2-methoxyethoxy, 2-ethoxyethoxy or hydroxy, R.sup.1 represents C.sub.1 -C.sub.3 -alkyl, phenyl or C.sub.5 -C.sub.7 -cycloalkyl, n is 0, 1 or 2, m is 1 or 2 and m+n is 1, 2 or 3 with sulphur as well as in a given case hydrogen sulphide in molar ratios of vinyl silane to sulphur of from 1:2.5 to 1:10 and vinyl silane to hydrogen sulphide of from 1:0 to 1:5 at temperatures between about 100.degree. and 200.degree. C. under pressure of from 1 to 25 bars (total pressure at the reaction temperature) and in the presence of sulphidation catalysts known per se, in a given case followed by hydrolysis or partial hydrolysis of the reaction products.
    Type: Grant
    Filed: July 13, 1981
    Date of Patent: May 17, 1983
    Assignee: Degussa Aktiengesellschaft
    Inventors: Rudolf Schwarz, Peter Kleinschmit, Christa Liedtke, Siegfried Wolff
  • Patent number: 4011656
    Abstract: A hair cutter comprising a cover plate displaceably disposed relative to and opposite a blade carrier plate, the cover plate having a row of teeth covering a blade cutting edge. Downwardly pointing teeth-like arresting projections are mounted on a flanged downwardly facing part of the blade carrier plate and positively engage upwardly pointing arresting teeth on lateral shoulders of a push button actuating element, the latter disposed perpendicular to the plane of the blade. The arresting projections are biased into an arresting position and are releasable by a push button actuating element which slidably projects through a complementary opening formed in the cover plate, whereby the arresting teeth of the shoulders being released from the downwardly pointing and complementary arresting teeth upon pushing the push button actuating element downwardly.
    Type: Grant
    Filed: June 20, 1975
    Date of Patent: March 15, 1977
    Inventor: Christa Liedtke
  • Patent number: 3986258
    Abstract: A hair cutter comprising a blade interchangeably retained between a blade-supporting plate and a cover plate, the latter having a row of teeth which overlaps said blade cutting edge. The plates are displaceable perpendicularly to the blade cutting edge and relatively to one another between two end positions, and the blade-supporting plate bears the blade as far as adjacent the cutting edge, yet leaving the blade cutting edge exposed. In a zone adjoining the blade cutting edge, the blade-supporting plate has at least in part a wedge-shaped portion increasing in thickness extending from the blade cutting edge in a rearward direction, so that when the hair cutter is placed on the head of the user the blade is adjustable to a cutting angle determined by front ends of the teeth and application portions of the wedge-shaped portion on the user's head.
    Type: Grant
    Filed: May 2, 1974
    Date of Patent: October 19, 1976
    Assignee: Dieter W. Liedtke
    Inventor: Christa Liedtke