Patents by Inventor Friedrich B. Bielfeldt

Friedrich B. Bielfeldt 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: 6533890
    Abstract: A method and apparatus for the production of ligneous material boards characterized by a positive separation of the press platen applying the compression pressure from the mat at the frame sealing the outer margin, so that the press pressure is applied independently of the pressure required for the sealing.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: March 18, 2003
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Co.
    Inventors: Susanne Berger, Friedrich B. Bielfeldt
  • Patent number: 6502326
    Abstract: A method and apparatus for reducing the moisture content bound by capillarity in fiber cells of solid materials containing carbon. The material is ground and screened to form a loose sheet of the solid materials and/or sludges. The material is processed by screening and grinding methods for a plurality of hoppers for different grain sizes and grain size distributions. A thin layer of fines is spread as a first layer onto the spreading, feeding and filter belt, and a substantially thicker coarse material layer is formed as a second layer to form a sandwich of the material. The fines layer depth HF and coarse material depth HG of the sandwich correspond to the consistency and the proportion of the fines of the material. The sandwich formed is then carried by a belt into the pressure chamber of the filter press according to the dewatering cycle, while simultaneously the squeezed-out dry material is carried away.
    Type: Grant
    Filed: August 25, 2000
    Date of Patent: January 7, 2003
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Co.
    Inventor: Friedrich B. Bielfeldt
  • Patent number: 6499232
    Abstract: A method and an apparatus for reducing the moisture content bound by capillary action in fiber cells. To include fine material economically and easily in the process, coarse material is sandwiched on top of fine material and then pressed and dried. The material prepared by grinding and screening is transferred as coarse material to a first spreader hopper, and the screened fine material is transferred over a chute and conveyor belt to a second spreader hopper. The fine material is spread in a thin layer through a vertically adjustable gate from the second spreader hopper onto a spreading, loading and filtering belt, and the coarse material is withdrawn on a transfer conveyor belt running below the first spreader hopper and then is spread through a vertically adjustable gate onto the fine layer, to form a sandwich-like mat.
    Type: Grant
    Filed: April 9, 2001
    Date of Patent: December 31, 2002
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Co
    Inventor: Friedrich B. Bielfeldt
  • Patent number: 6444079
    Abstract: A process and an apparatus for producing endless laminated veneer boards from a veneer-panel strand comprising veneer panels laid together in a plurality of layers by means of gluing and compression in a heated, continuously operating press. The veneer-panel strand is run through a preliminary press with a preheating device before it enters the press. The layers of glue applied to the veneer panels and/or the veneer panels for the center or a central-layer strand have a higher moisture content than the layers of glue and/or the veneer panels for the outer layers or the cover-layer strands. The veneer panels are each then assembled to give an upper and a lower cover-layer strand and, if required, a central-layer strand, and are combined to give a veneer-panel strand.
    Type: Grant
    Filed: August 9, 1999
    Date of Patent: September 3, 2002
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Co.
    Inventor: Friedrich B. Bielfeldt
  • Patent number: 6402877
    Abstract: A process and an apparatus for producing endless laminated veneer boards from a veneer-panel strand comprising veneer panels laid together in a plurality of layers by means of gluing and compression in a heated, continuously operating press. The veneer-panel strand is run through a preliminary press with a preheating device before it enters the press. The preliminary press comprises a high-frequency or microwave-energy preheating device, the preheating device being adapted to focus energy and a reflection of said energy in a central region of veneer-panel strand.
    Type: Grant
    Filed: August 9, 1999
    Date of Patent: June 11, 2002
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Co.
    Inventor: Friedrich B. Bielfeldt
  • Publication number: 20020000416
    Abstract: A method and an apparatus for reducing the moisture content bound by capillary action in fiber cells. To include fine material economically and easily in the process, coarse material is sandwiched on top of fine material and then pressed and dried. The material prepared by grinding and screening is transferred as coarse material to a first spreader hopper, and the screened fine material is transferred over a chute and conveyor belt to a second spreader hopper. The fine material is spread in a thin layer through a vertically adjustable gate from the second spreader hopper onto a spreading, loading and filtering belt, and the coarse material is withdrawn on a transfer conveyor belt running below the first spreader hopper and then is spread through a vertically adjustable gate onto the fine layer, to form a sandwich-like mat.
    Type: Application
    Filed: April 9, 2001
    Publication date: January 3, 2002
    Inventor: Friedrich B. Bielfeldt
  • Patent number: 6328843
    Abstract: A method for continuously producing finished board from a mat of a pressing stock mixed with a binder in a continuously operating press having steel belts, friction reducing elements, heating plates and cooling plates, the method comprising choosing a cooling length of a cooling section to cure the mat of pressing stock and to ensure a harmless vapor pressure within a finished board; introducing the mat between the steel belts of the continuously operating press; heating and pressing the pressing stock in a heating section of the continuously operating press; and cooling surfaces of the pressing mat just before the reaction starting temperature is reached, wherein the surfaces of the mat are subject to cooling when the temperature at the center of the stock is about 85% to 95% of the temperature required for curing the pressing stock. A continuously operating press for producing boards from a pressing stock has a press table and a press ram located above the press table.
    Type: Grant
    Filed: August 13, 1999
    Date of Patent: December 11, 2001
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Company
    Inventors: Friedrich B. Bielfeldt, Matthias Graf
  • Patent number: 6290809
    Abstract: The invention relates to a process for the production of boards of wood-based material from a mixture of lignocellulose- and/or cellulose-containing particles mixed with a binder, the mat or pressed stock being preheated by means of high-frequency (HF) or microwave (MW) energy and, after transfer into a single or multi-platen press or a continuously operating press, being pressed and cured by the application of pressure and heat. To increase the preheating temperature of the pressed stock and to reduce the pressing factor, the following process steps are provided: (a) the preheating in the core of the mat of pressed stock to ≧85° Celsius takes place after or during the precompaction by traveling wave microwave energy and its reflection in an interaction between emitted and reflected energy into the center of the mat of pressed stock, a.
    Type: Grant
    Filed: July 1, 1999
    Date of Patent: September 18, 2001
    Assignee: Maschinenfabrik J. Dieffenbacher
    Inventors: Friedrich B. Bielfeldt, Werner Hoffmann
  • Patent number: 6176951
    Abstract: The invention relates to a process for the production of boards of wood-based material from a mixture of lignocellulose- and/or cellulose-containing particles mixed with a binder, the mat or pressed stock being preheated by means of high-frequency (HF) or microwave (MW) energy and, after transfer into a single or multi-platen press or a continuously operating press, being pressed and cured by the application of pressure and heat.
    Type: Grant
    Filed: May 4, 1998
    Date of Patent: January 23, 2001
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Co.
    Inventors: Friedrich B. Bielfeldt, Werner Hoffmann
  • Patent number: 6054081
    Abstract: A process and installation for the continuous production of boards of wood-based material, includes the steps of forming on a continuously moving scattering belt, a pressed material mat includes an initial mixture of chips and/or fibers from a scattering station and mixed with binder; precompacting and preheating the pressed material mat between the scattering station and a main pressing region; and bringing into an end form and curing the pressed material with the application of pressure and heat in a main pressing regions. The moisture level of the pressed material mat is less on entry into the main pressing region than the moisture level of the initial mixture in the scattering of the pressed material mat, part of the moisture imparted to it in the scattering being extracted again by hot-air preheating.
    Type: Grant
    Filed: November 17, 1995
    Date of Patent: April 25, 2000
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Co.
    Inventor: Friedrich B. Bielfeldt
  • Patent number: 5950532
    Abstract: A continuously operating press for the production of particleboards, fiberboards or similar wooden-material boards and plastic sheets allows for the free longitudinal expansion or contraction of the press heating plates by having a press force frame structure of individual press frames positioned between support carriers and mounted on sliding members on the lower support carriers. The sliding members are designed as rolling wheel segments that are assigned to each individual frame of the press force support structure.
    Type: Grant
    Filed: June 2, 1997
    Date of Patent: September 14, 1999
    Assignee: Machinenfabrik J. Dieffenbacher GmbH & Co.
    Inventor: Friedrich B. Bielfeldt
  • Patent number: 5942079
    Abstract: Veneer panels which are to be joined in a plurality of layers one above the other and one behind the other are assembled and glued to form an endless strand of veneer laminates. In the process, the veneer panels are first fed in through a glue-application machine which applies a layer of glue on a top side of the veneer panels onto a buffer belt. The veneer panels are then transferred from the buffer belt to a horizontally reversing feed belt which forms on a roller table a first veneer assembly comprising a plurality of veneer panels. The first veneer assembly is raised about its front end by an angle .alpha. into an oblique position so that veneer panels of a subsequent veneer assembly can be threaded into the first veneer assembly using the horizontally reversing feed belt. The first and subsequent veneer assemblies are thereby combined into a veneer-panel strand, and transferred to a continuously operating prepress and press.
    Type: Grant
    Filed: August 19, 1998
    Date of Patent: August 24, 1999
    Assignee: Mashinenfabrik J. Dieffenbacher GmbH & Co.
    Inventors: Friedrich B. Bielfeldt, Werner Hoffmann, Gerhard Melzer
  • Patent number: 5900139
    Abstract: A filter press for reducing the water content in a starting material including a pressure chamber with a stationary lower plate and five hydraulically mobile chamber walls for applying pressure to the starting material.
    Type: Grant
    Filed: March 21, 1997
    Date of Patent: May 4, 1999
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Co.
    Inventor: Friedrich B. Bielfeldt
  • Patent number: 5895546
    Abstract: Veneer panels which are to be joined in a plurality of layers one above the other and one behind the other are assembled and glued to form an endless strand of veneer laminates. In the process, the veneer panels are first fed in through a glue-application machine which applies a layer of glue on a top side of the veneer panels onto a buffer belt. The veneer panels are then transferred from the buffer belt to a horizontally reversing feed belt which forms on a roller table a first veneer assembly comprising a plurality of veneer panels. The first veneer assembly is raised about its front end by an angle .alpha. into an oblique position so that veneer panels of a subsequent veneer assembly can be threaded into the first veneer assembly using the horizontally reversing feed belt. The first and subsequent veneer assemblies are thereby combined into a veneer-panel strand, and transferred to a continuously operating prepress and press.
    Type: Grant
    Filed: April 9, 1997
    Date of Patent: April 20, 1999
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Co.
    Inventors: Friedrich B. Bielfeldt, Werner Hoffman, Gerhard Melzer
  • Patent number: 5887514
    Abstract: The invention relates to a method, a press, and a control device for reducing the capillary-bound water content in fiber cells of carbon-containing, finely comminuted solid materials and/or sludges. The method according to the invention includes rapidly raising the movable press plate of a filter press while the pressure chamber remains closed. A steam-coal dust mixture is formed due to the rapid expansion. At the same time, a first discharge lock is opened while the second discharge lock remains closed so that the exhaust steam flows in the direction of the controlled outlet valve. The exhaust steam can then be sent to a heat exchanger and then to another heat exchanger and, finally, may be reused for a subsequent operating cycle.
    Type: Grant
    Filed: March 21, 1997
    Date of Patent: March 30, 1999
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Co.
    Inventors: Friedrich B. Bielfeldt, Eckhard Kintscher
  • Patent number: 5875708
    Abstract: A method of controlling the press force on at least one press heating plate along the press length of an operating cycle. For a reduction of specific press force from a maximum press force towards a zero press force, a setting force for a longitudinal deformation of the at least one press heating plate is increased accordingly. For an increase in the specific press force from a zero press force towards a maximum press force, the setting force for the longitudinal deformation of the press heating plates is reduced accordingly. For a reduction of the specific press force from the maximum press force towards the zero press force, the longitudinal gradient tan .beta. is set to be approximately twice as large as the gradient tan .alpha. at the press force maximum. The longitudinal gradient and setting force can thus be controlled along an entire pressing path for an increase or decrease in the specific press force.
    Type: Grant
    Filed: June 2, 1997
    Date of Patent: March 2, 1999
    Assignee: Machinenfabrik J. Dieffenbacher GmBH & Co.
    Inventor: Friedrich B. Bielfeldt
  • Patent number: 5862612
    Abstract: Water content which is bound by capillarity in fiber cells of carboniferous materials is reduced by a thermomechanical dewatering process. In the process, the carboniferous materials are conveyed by a dispersion box into a pressure chamber including upper and lower plates. Steam is applied to the materials introduced into the pressure chamber from both the upper and lower plates to heat the materials up to about 125.degree. C. and to release the water which is bound by capillarity in the fiber cells. Initially, the pressure within the chamber is maintained at no greater than the steam pressure. Subsequently, the pressure chamber is sealed gastight and the carboniferous materials in the pressure chamber are pressed using the upper and lower plates.
    Type: Grant
    Filed: September 23, 1996
    Date of Patent: January 26, 1999
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Co.
    Inventor: Friedrich B. Bielfeldt
  • Patent number: 5788810
    Abstract: A continuously operating press includes a press ram, a press table, flexible, endless steel bands which draw in a pressable material and transmit press pressure to the pressable material, drive and, deflecting rollers for guiding the steel bands around the press table and the press ram, upper and lower heating plates disposed between the press ram and the press table and between which a press nip is defined, and press cylinder-piston arrangements for adjusting the press nip. Tensioning brackets which are connected to the press table have openings within which the press cylinder-piston arrangements are received. Further, short-stroke cylinder-piston arrangements are arranged transversely with respect to the pressing path and beneath the lower press heating plate to permit a concave or convex deformation in the transverse direction.
    Type: Grant
    Filed: June 2, 1997
    Date of Patent: August 4, 1998
    Assignee: Machinenfabrik J. Diefenbacher GmbH & Co.
    Inventor: Friedrich B. Bielfeldt
  • Patent number: 5775214
    Abstract: A continuously operating press produces particle, fiber, plastic and wood boards continuously from pressing stock. The press includes a heating platen provided on one side of the press and a plurality of press platen segments arranged on a side opposite to the heating platen. The press platen segments are resiliently coupled to one another by snap-action hinges and the separation space between the press platen segments and the heating platen is independently adjusted. The pressing stock is pulled through the separation space which has been optimally controlled to produce boards with desired density profiles at a maximum production speed.
    Type: Grant
    Filed: May 28, 1996
    Date of Patent: July 7, 1998
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Co.
    Inventors: Friedrich B. Bielfeldt, Detlef Kroll
  • Patent number: 5762980
    Abstract: A process and installation for the continuous production of boards of wood-based material, includes the steps of forming on a continuously moving scattering belt, a pressed material mat includes an initial mixture of chips and/or fibers from a scattering station and mixed with binder; precompacting and preheating the pressed material mat between the scattering station and a main pressing region; and bringing into an end form and curing the pressed material with the application of pressure and heat in a main pressing regions. The moisture level of the pressed material mat is less on entry into the main pressing region than the moisture level of the initial mixture in the scattering of the pressed material mat, part of the moisture imparted to it in the scattering being extracted again by hot-air preheating.
    Type: Grant
    Filed: February 3, 1997
    Date of Patent: June 9, 1998
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Co.
    Inventor: Friedrich B. Bielfeldt