Patents by Inventor Walter Lehmann

Walter Lehmann 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).

  • Publication number: 20200131069
    Abstract: A known method for homogenizing glass includes the following steps: providing a cylindrical blank composed of the glass, having a cylindrical outer surface which extends between a first end face and a second end face, forming a shear zone in the blank by softening a longitudinal section of the blank and subjecting it to a thermal-mechanical intermixing treatment, and moving the shear zone along the longitudinal axis of the blank. To reduce the risk of cracks and fractures during homogenizing, it is proposed that a thermal radiation dissipator is used that at least partially surrounds the shear zone, the lateral dimension of which in the direction of the longitudinal axis of the blank is greater than the shear zone and smaller than the length of the blank, the thermal radiation dissipator being moved synchronously with the shear zone along the longitudinal axis of the blank.
    Type: Application
    Filed: October 24, 2019
    Publication date: April 30, 2020
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Stephan Thomas, Jan Vydra, Martin Trommer, Michael Huenermann, Andreas Langner, Walter Lehmann, Stefan Hengster, Klaus Becker
  • Publication number: 20200131071
    Abstract: A method for homogenizing glass includes the method: providing a cylindrical blank composed of the glass having a cylindrical outer surface that extends along a longitudinal axis of the blank between a first end face and a second end face, forming a shear zone in the blank by softening a longitudinal section of the blank and subjecting it to a thermal-mechanical intermixing treatment, and displacing the shear zone along the longitudinal axis of the blank. To enable a radial mixing within the shear zone in addition to the tangential mixing with the lowest possible time and energy input, starting from this method, cylindrical sections of the blank are adjacent to the shear zone on both sides, the first cylindrical section having a first central axis and the second cylindrical section having a second central axis, the first central axis and the second central axis being temporarily non-coaxial with each other.
    Type: Application
    Filed: October 24, 2019
    Publication date: April 30, 2020
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Stephan Thomas, Jan Vydra, Martin Trommer, Michael Huenermann, Andreas Langner, Walter Lehmann, Stefan Hengster, Klaus Becker
  • Patent number: 10618833
    Abstract: The invention relates to a process for the preparation of a quartz glass grain comprising the process steps i.) Providing a silicon dioxide granulate from a pyrogenically produced silicon dioxide powder, ii.) Making a glass melt out of silicon dioxide granulate, iii.) Making a quartz glass body out of at least part of the glass melt and iv.) Reducing the size of the quartz glass body to obtain the quartz glass grain. The invention further relates to a quartz glass grain which is obtainable by this process. The invention further relates to opaque quartz glass bodies, which are obtainable by further processing of the quartz glass grain.
    Type: Grant
    Filed: December 16, 2016
    Date of Patent: April 14, 2020
    Assignee: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Martin Arndt, Matthias Otter, Walter Lehmann, Michael Hünermann, Nils Christian Nielsen, Nigel Robert Whippey, Boris Gromann, Abdoul-Gafar Kpebane
  • Publication number: 20190356273
    Abstract: A circuit arrangement for generating a supply voltage with a controllable ground potential level includes a voltage source that provides the supply voltage ungrounded, a control unit that generates an adjustable control d.c. voltage to ground, and an operational amplifier that is connected via its voltage supply terminals to the supply voltage source, where the control d.c. voltage is applied to the inverting input of the operational amplifier, the non-inverting input of the operational amplifier is connected via a resistor network to the voltage source and to a ground terminal and the output of the operational amplifier is fed back to the inverting input via a capacitor.
    Type: Application
    Filed: May 14, 2019
    Publication date: November 21, 2019
    Inventors: Walter Kreb, Ulrich LEHMANN, Wilhelm GRIESBAUM
  • Patent number: 10336645
    Abstract: A method for producing rare earth metal-doped quartz glass includes the steps of (a) providing a blank of the rare earth metal-doped quartz glass, and (b) homogenizing the blank by softening the blank zone by zone in a heating zone and by twisting the softened zone along a rotation axis. Some rare earth metals, however, show a discoloration of the quartz glass, which hints at an unforeseeable and undesired change in the chemical composition or possibly at an inhomogeneous distribution of the dopants. To avoid this drawback and to provide a modified method which ensures the production of rare earth metal-doped quartz glass with reproducible properties, during homogenization according to method step (b), the blank is softened under the action of an oxidizingly acting or a neutral plasma.
    Type: Grant
    Filed: June 27, 2017
    Date of Patent: July 2, 2019
    Assignee: Heraeus Quarzglas GmbH & Co., KG
    Inventors: Hardy Baierl, Stephan Grimm, Kay Schuster, Jan Dellith, Andreas Langner, Gerhard Schoetz, Walter Lehmann, Thomas Kayser
  • Publication number: 20190152827
    Abstract: One aspect relates to a process for the preparation of a quartz glass body, including providing a silicon dioxide granulate, making a glass melt out of silicon dioxide granulate and making a quartz glass body out of at least part of the glass melt. The silicon dioxide granulate is obtained by providing and processing a silicon dioxide powder. One aspect also relates to silicon dioxide granulate, which is obtained by providing a silicon dioxide powder and processing it. One aspect further relates to a quartz glass body which is obtainable by this process. One aspect further relates to a light guide, an illuminant and a formed body, which are each obtainable by further processing of the quartz glass body.
    Type: Application
    Filed: December 16, 2016
    Publication date: May 23, 2019
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Matthias OTTER, Walter LEHMANN, Michael HÜNERMANN, Nils Christian NIELSEN, Martin TROMMER
  • Patent number: 10287705
    Abstract: In a known method for pulling a semiconductor single crystal according to the Czochralski method, a semiconductor melt is produced in a silica glass crucible and the semiconductor single crystal is pulled from said melt. The inner wall of the silica glass crucible and the exposed melt surface are in contact with one another and with a respective melt atmosphere in the region of a contact zone running radially around the crucible inner wall, and primary oscillations of the melt are triggered in said contact zone. On this basis, in order to provide a method characterized by reduced melt vibrations and in particular by a simple, short accretion process, according to the invention primary oscillations are triggered which differ from one another in their frequency.
    Type: Grant
    Filed: December 6, 2017
    Date of Patent: May 14, 2019
    Assignee: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Michael Hünermann, Thomas Kayser, Walter Lehmann
  • Publication number: 20190092676
    Abstract: The invention relates to a process for the preparation of a quartz glass body comprising the process steps i.) Providing a silicon dioxide granulate, ii.) Making a glass melt from the silicon dioxide granulate in an oven, and iii.) Making a quartz glass body from at least a part of the glass melt, wherein the oven comprises a hanging sinter crucible. The invention also relates to a quartz glass body which is obtainable by this process. The invention further relates to a light guide, an illuminant and a formed body which are each obtainable by further processing the quartz glass body.
    Type: Application
    Filed: December 16, 2016
    Publication date: March 28, 2019
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Matthias OTTER, Walter LEHMANN, Michael HÜNERMANN, Nils Christian NIELSEN, Nigel Robert WHIPPEY, Boris GROMANN, Abdoul-Gafar KPEBANE
  • Publication number: 20190077688
    Abstract: One aspect relates to a process for the provision of a quartz glass body, including providing a silicon dioxide granulate, making a glass melt from the silicon dioxide granulate in an oven and making a quartz glass body from at least part of the glass melt. The oven includes a hanging metal sheet crucible. One aspect also relates to a quartz glass body which is obtainable by this process. One aspect further relates to a light guide, an illuminant and a formed body which are obtainable by processing the quartz glass body further.
    Type: Application
    Filed: December 16, 2016
    Publication date: March 14, 2019
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Matthias OTTER, Walter LEHMANN, Michael HÜNERMANN, Nils Christian NIELSEN, Nigel Robert WHIPPEY, Boris GROMANN, Abdoul-Gafar KPEBANE
  • Publication number: 20190077672
    Abstract: One aspect is a process for the preparation of a quartz glass body including providing a silicon dioxide granulate wherein the provision includes providing silicon dioxide powder, and processing the silicon dioxide powder to obtain a silicon dioxide granulate. The silicon dioxide granulate has a larger particle diameter than the silicon dioxide powder. The processing includes processing the silicon dioxide powder to obtain a silicon dioxide granulate I, wherein the silicon dioxide granulate I has a first carbon content wC(1), treating the silicon dioxide granulate I with a reactant to obtain a silicon dioxide granulate II with a further carbon content wC(2), wherein the further carbon content wC(2) is less than the first carbon content wC(1), making a glass melt out of the silicon dioxide granulate and making a quartz glass body out of at least part of the glass melt.
    Type: Application
    Filed: December 16, 2016
    Publication date: March 14, 2019
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Matthias OTTER, Walter LEHMANN, Michael HÜNERMANN, Nils Christian NIELSEN, Nigel Robert WHIPPEY, Boris GROMANN, Abdoul-Gafar KPEBANE, Thomas KAYSER
  • Publication number: 20190071342
    Abstract: One aspect relates to a process for preparing a quartz glass body, including providing a silicon dioxide granulate, making a glass melt from the silicon dioxide granulate in a melting crucible, making a quartz glass body from at least a part of the glass melt, and treating the quartz glass body with at least one procedure selected from the group consisting of chemical, thermal or mechanical treatment to obtain a treated quartz glass body. One aspect also relates to a quartz glass body which is obtainable by this process. One aspect also concerns a light guide, an illuminant and a formed body each obtainable by processing the quartz glass body further.
    Type: Application
    Filed: December 16, 2016
    Publication date: March 7, 2019
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Matthias OTTER, Walter LEHMANN, Michael HÜNERMANN, Nils Christian NIELSEN, Nigel Robert WHIPPEY, Boris GROMANN, Abdoul-Gafar KPEBANE
  • Publication number: 20190071344
    Abstract: The invention relates to a process for preparing a quartz glass body comprising the process steps i.) Providing a silicon dioxide granulate, ii.) Making a glass melt from the silicon dioxide granulate in a melting crucible, and iii.) Making a quartz glass body from at least a part of the glass melt, wherein the melting crucible is comprised in an oven and is made of at least one material comprising tungsten or molybdenum or a combination thereof. The invention further relates to a quartz glass body which can be obtained by this process. Further, the invention relates to a light guide, an illuminant and a formed body, each of which can be obtained by processing the quartz glass body further.
    Type: Application
    Filed: December 16, 2016
    Publication date: March 7, 2019
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Matthias OTTER, Walter LEHMANN, Michael HÜNERMANN, Nils Christian NIELSEN, Nigel Robert WHIPPEY, Boris GROMANN, Abdoul-Gafar KPEBANE
  • Publication number: 20190062197
    Abstract: The invention relates to a process for the preparation of a quartz glass body comprising the process steps i.) Providing a silicon dioxide granulate obtainable from a silicon dioxide powder, wherein the silicon dioxide granulate has a larger particle size than the silicon dioxide powder, ii.) Making a glass melt out of silicon dioxide granulate and iii.) Making a quartz glass body out of at least part of the glass melt, wherein the melting crucible has at least one inlet and at least one outlet, wherein at least part of the glass melt is removed via the melting crucible outlet. The invention further relates to a quartz glass body which is obtainable by this process. The invention further relates to a light guide, an illuminant and a formed body, which are each obtainable by further processing of the quartz glass body.
    Type: Application
    Filed: December 16, 2016
    Publication date: February 28, 2019
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Matthias OTTER, Walter LEHMANN, Michael HÜNERMANN, Nils Christian NIELSEN, Mirko WITTRIN, Markus WILDE
  • Publication number: 20190062193
    Abstract: The invention relates to a process for the preparation of a quartz glass body comprising the process steps i.) Providing a silicon dioxide granulate, wherein the silicon dioxide granulate was made from pyrogenic silicon dioxide powder and the silicon dioxide granulate has a BET surface area in a range from 20 to 40 m2/g, ii.) Making a glass melt out of silicon dioxide granulate in an oven and iii.) Making a quartz glass body out of at least part of the glass melt, wherein the oven has at least a first and a further chamber connected to one another via a passage, wherein the temperature in the first chamber is lower than the temperature in the further chambers. The invention further relates to a quartz glass body which is obtainable by this process. The invention further relates to a light guide, an illuminant and a formed body, which are each obtainable by further processing of the quartz glass body.
    Type: Application
    Filed: December 16, 2016
    Publication date: February 28, 2019
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Matthias OTTER, Walter LEHMANN, Michael HÜNERMANN, Nils Christian NIELSEN, Nigel Robert WHIPPEY, Boris GROMANN, Abdoul-Gafar KPEBANE, Matthias SÖHN
  • Publication number: 20190062194
    Abstract: The invention relates to a process for the preparation of a quartz glass body comprising the process steps i.) Providing a silicon dioxide granulate, ii.) Making a glass melt out of the silicon dioxide granulate and iii) Making a quartz glass body out of at least part of the glass melt, wherein the provision comprises the steps I. Providing a silicon dioxide powder with at least two particles made from a silicon-chlorine compound, II. Bringing the silicon dioxide powder into contact with steam to obtain a treated silicon dioxide powder and III. Granulating the treated silicon dioxide powder to obtain a silicon dioxide granulate, and wherein the chorine content of the silicon dioxide powder is greater than the chlorine content of the silicon dioxide granulate. The invention further relates to a quartz glass body which is obtainable by this process. The invention further relates to a process for providing a silicon dioxide granulate.
    Type: Application
    Filed: December 16, 2016
    Publication date: February 28, 2019
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Matthias OTTER, Walter LEHMANN, Michael HÜNERMANN, Nils Christian NIELSEN, Nigel Robert WHIPPEY, Boris GROMANN, Abdoul-Gafar KPEBANE, Thomas KAYSER
  • Publication number: 20190031554
    Abstract: The invention relates to a process for the preparation of a quartz glass body comprising the process steps i.) Providing a silicon dioxide granulate, ii.) Making a glass melt out of silicon dioxide granulate in an oven and iii.) Making a quartz glass body out of at least part of the glass melt, wherein the oven comprises a standing sinter crucible. The invention further relates to a quartz glass body which is obtainable by this process. The invention further relates to a light guide, an illuminant and a formed body, which are each obtainable by further processing of the quartz glass body.
    Type: Application
    Filed: December 16, 2016
    Publication date: January 31, 2019
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Matthias OTTER, Walter LEHMANN, Michael HÜNERMANN, Nils Christian NIELSEN, Nigel Robert WHIPPEY, Boris GROMANN, Abdoul-Gafar KPEBANE
  • Publication number: 20180370838
    Abstract: One aspect relates to a process for the preparation of a quartz glass body, including provision of a silicon dioxide granulate, making a glass melt from the silicon dioxide granulate and making a quartz glass body from at least part of the glass melt. The provision includes making a silicon dioxide powder with at least two particles prepared from a silicon-chlorine compound, bringing the silicon dioxide powder into contact with ammonia to obtain a treated silicon dioxide powder, and granulating the treated silicon dioxide powder to obtain a silicon dioxide granulate. The chlorine content of the silicon dioxide powder is greater than the chlorine content of the silicon dioxide granulate. One aspect relates further to a quartz glass body which is obtainable by this process. One aspect also relates to a process for the preparation of a silicon dioxide granulate.
    Type: Application
    Filed: December 16, 2016
    Publication date: December 27, 2018
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Matthias OTTER, Walter LEHMANN, Michael HÜNERMANN, Nils Christian NIELSEN, Nigel Robert WHIPPEY, Boris GROMANN, Abdoul-Gafar KPEBANE, Thomas KAYSER
  • Publication number: 20180362385
    Abstract: One aspect relates to a process for the preparation of a quartz glass grain, including providing a silicon dioxide granulate from a pyrogenically produced silicon dioxide powder, making a glass melt out of silicon dioxide granulate, making a quartz glass body out of at least part of the glass melt and reducing the size of the quartz glass body to obtain the quartz glass grain. One aspect further relates to a quartz glass grain which is obtainable by this process. One aspect further relates to opaque quartz glass bodies, which are obtainable by further processing of the quartz glass grain.
    Type: Application
    Filed: December 16, 2016
    Publication date: December 20, 2018
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Martin ARNDT, Matthias OTTER, Walter LEHMANN, Michael HÜNERMANN, Nils Christian NIELSEN, Nigel Robert WHIPPEY, Boris GROMANN, Abdoul-Gafar KPEBANE
  • Publication number: 20180282196
    Abstract: A method for producing a component with portions of a rare earth metal-doped quartz glass, an intermediate product containing voids and consisting of a SiO2 raw material doped with rare earth metal is introduced into a sinter mold the interior of which is bordered by a carbonaceous mold wall, and is melted therein into the component by gas pressure sintering at a maximum temperature above 1500° C. A shield is arranged between the mold wall and the intermediate product. In order to indicate a modified gas pressure sintering method that ensures the production of rare earth metal-doped quartz glass with reproducible properties, a bulk material of amorphous SiO2 particles with a layer thickness of at least 2 mm is used as the shield, the softening temperature thereof being at least 20° C.
    Type: Application
    Filed: March 28, 2018
    Publication date: October 4, 2018
    Applicant: Heraeus Quarzglas GmbH & Co. KG
    Inventors: Walter Lehmann, Mario Such, Thomas Kayser, Andreas Langner, Gerhard Schötz
  • Publication number: 20180112327
    Abstract: In a known method for pulling a semiconductor single crystal according to the Czochralski method, a semiconductor melt is produced in a silica glass crucible and the semiconductor single crystal is pulled from said melt. The inner wall of the silica glass crucible and the exposed melt surface are in contact with one another and with a respective melt atmosphere in the region of a contact zone running radially around the crucible inner wall, and primary oscillations of the melt are triggered in said contact zone. On this basis, in order to provide a method characterised by reduced melt vibrations and in particular by a simple, short accretion process, according to the invention primary oscillations are triggered which differ from one another in their frequency.
    Type: Application
    Filed: December 6, 2017
    Publication date: April 26, 2018
    Inventors: Michael Hünermann, Thomas Kayser, Walter Lehmann