Patents by Inventor Rexford H. Bradt

Rexford H. Bradt 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: 6261488
    Abstract: A method for suppression of weld line weakening by virtually eliminating weld lines is disclosed. The process involves the near explosive injection of a metered amount of foamed thermoplastic molding material into an enclosing compartment formed by partly closing a compression type mold followed immediately by compression molding of the well mixed foamed material. The process finds particular utility in the manufacture of very long fiber reinforced parts. Variations on mold design and clamping cycles yield a variety of parts having foamed regions surrounded by more dense un-foamed regions. The method is particularly well adapted to the manufacture of large, very long fiber reinforced, foam-centered, hard surfaced, light weight, rigid parts.
    Type: Grant
    Filed: November 2, 1994
    Date of Patent: July 17, 2001
    Assignee: Materials Research Innovations Corporation
    Inventor: Rexford H. Bradt
  • Patent number: 6143410
    Abstract: Process and product for manufacturing continuous fiber reinforced sheets and shapes. A pressurized extrusion process consisting of a paired and edge enclosing doctor blades that remove feed material from a pair of pinch rolls and contain such in an optimally heated environment and which provides suitable hot dies and enables extrusion of continuous reinforcements, cores or threads to be contained in the extrudite.Hopper feedable plastic pellets containing reinforcing fibers which are longer than the largest pellet dimension are disclosed. The fibers in an elongated web of fiber reinforced plastic are caused to be wrinkled or folded prior to cutting the web into pellets. One form of apparatus includes a set of conveyor rollers for moving the web, with later rollers moving more slowly than the input rollers, in conjunction with a crowding doctor blade which forces the web with a creping action from the input rollers.
    Type: Grant
    Filed: February 5, 1996
    Date of Patent: November 7, 2000
    Assignee: Materials Research Innovations Corporation
    Inventor: Rexford H. Bradt
  • Patent number: 6129539
    Abstract: A material transfer arrangement having a pair of generally cylindrical adjacent rolls which are counter-rotatable about their respective cylindrical axes and which define therebetween a nip between which material passes is disclosed. There is a corresponding pair of spaced apart doctor blades, each in close proximity to a corresponding one of the rolls so that material may be conveyed between the roll nip and the space between the doctor blades. In one form, the nip passes material to the space between the doctor blades and that space has a downstream restriction which causes the material to compress in an accordion-like way forming a corrugated material web. In another form, the doctor blades function to deliver thermoplastic extrudate to the nip between the rolls to form elongated sheets or webs of plastic material of improved uniformity.
    Type: Grant
    Filed: July 23, 1998
    Date of Patent: October 10, 2000
    Assignee: Materials Research Innovations Corporation
    Inventor: Rexford H. Bradt
  • Patent number: 5800765
    Abstract: A material transfer arrangement having a pair of generally cylindrical adjacent rolls which are counter-rotatable about their respective cylindrical axes and which define therebetween a nip between which material passes is disclosed. There is a corresponding pair of spaced apart doctor blades, each in close proximity to a corresponding one of the rolls so that material may be conveyed between the roll nip and the space between the doctor blades. In one form, the nip passes material to the space between the doctor blades and that space has a downstream restriction which causes the material to compress in an accordion-like way forming a corrugated material web. In another form, the doctor blades function to deliver thermoplastic extrudate to the nip between the rolls to form elongated sheets or webs of plastic material of improved uniformity.
    Type: Grant
    Filed: March 19, 1996
    Date of Patent: September 1, 1998
    Assignee: Materials Research Innovations Corporation
    Inventor: Rexford H. Bradt
  • Patent number: 5747548
    Abstract: Apparatus and method for the production of hopper feedable thermoplastic pellets having zones or compartments which contain physically separated reactants which react only after being melt-mixed, as in a screw type extruder, reciproscrew injection machine, or similar device which heat forms pellets into a larger mass. This new class of thermoplastic molding materials relies mainly on the relatively slow reaction kinetics of contained large molecule molding materials to provide a time interval after melt-mixing of zoned pelletized reactants in an extruder barrel or injection molding machine. During this time period, the thermoplastic molding material is easily filled into injection molds. As the reaction progresses, the material becomes more viscous and such flow is difficult or impossible. The involved reactions may continue after demolding at room temperature during a post molding cure, or appliance service generated heat may cause post molding cure.
    Type: Grant
    Filed: March 14, 1997
    Date of Patent: May 5, 1998
    Assignee: Materials Research Innovations Corporation
    Inventor: Rexford H. Bradt
  • Patent number: 5627218
    Abstract: Apparatus and method for the production of hopper feedable thermoplastic pellets having zones or compartments which contain physically separated reactants which react only after being melt-mixed, as in a screw type extruder, reciproscrew injection machine, or similar device which heat forms pellets into a larger mass. This new class of thermoplastic molding materials relies mainly on the relatively slow reaction kinetics of contained large molecule molding materials to provide a time interval after melt-mixing of zoned pelletized reactants in an extruder barrel or inflection molding machine. During this time period, the thermoplastic molding material is easily filled into injection molds. As the reaction progresses, the material becomes more viscous and such flow is difficult or impossible. The involved reactions may continue after demolding at room temperature during a post molding cure, or appliance service generated heat may cause post molding cure.
    Type: Grant
    Filed: March 20, 1995
    Date of Patent: May 6, 1997
    Inventor: Rexford H. Bradt
  • Patent number: 5500175
    Abstract: Process and product for manufacturing continuous fiber reinforced sheets and shapes. A pressurized extrusion process consisting of a paired and edge enclosing doctor blades that remove feed material from a pair of pinch rolls and contain such in an optimally heated environment and which provides suitable hot dies and enables extrusion of continuous reinforcements, cores or threads to be contained in the extrudite. Hopper feedable plastic pellets containing reinforcing fibers which are longer than the largest pellet dimension are disclosed. The fibers in an elongated web of fiber reinforced plastic are caused to be wrinkled or folded prior to cutting the web into pellets. One form of apparatus includes a set of conveyor rollers for moving the web, with later rollers moving more slowly that the input rollers, in conjunction with a crowding doctor blade which forces the web with a creping action from the input rollers.
    Type: Grant
    Filed: November 2, 1994
    Date of Patent: March 19, 1996
    Inventor: Rexford H. Bradt
  • Patent number: 4211736
    Abstract: A method of forming fibers from a flowable thermoplastic forming material wherein the fiber forming material is fed onto an outer surface of a spinning element which tapers inwardly to a terminal point and sweeping the fiber forming material with a flow of heated fluid along the surface of the spinning element and spinning the fiber forming material from the terminal point into congealed fibers under the continued influence of the sweeping fluid, cooling the uncongealed fibers to form a uniform suspension in the sweeping fluid and collecting the congealed fibers.
    Type: Grant
    Filed: January 31, 1977
    Date of Patent: July 8, 1980
    Assignee: Albert L. Jeffers
    Inventor: Rexford H. Bradt
  • Patent number: 4078957
    Abstract: A precision thermoplastic winding method and apparatus for forming heterogeneous pipe by winding a first hot thermoplastic strand on a mandrel, then applying a second strand of uncured thermosetting material on the first layer to form a second layer on the mandrel, and thereafter helically winding a hot thermoplastic strand on the second layer to form a third layer on the mandrel and to thus seal and cure the second layer of thermosetting material.
    Type: Grant
    Filed: December 2, 1976
    Date of Patent: March 14, 1978
    Inventor: Rexford H. Bradt
  • Patent number: 4010054
    Abstract: A precision thermoplastic filament winding process for forming into pipe or similar articles by winding strands comprised of semi-hardened thermoplastic material on a rotating mandrel to form a layer thereon.Single or multiple component, unreinforced and/or continuously reinforced filament wound cylindrical products are continuously produced by winding, at least an inner layer of thermoplastic material upon a rotating cooling mandrel which reciprocates axially in timed relation with moving guiding means and a rotary stripping means.Timing sequence provides a dwell relationship between the cooling mandrel and the hot semi-molten applied material so that at least the inner surface of the freshly applied material is rendered non-sticking and strong enough to enable it to be moved along the surface of the mandrel an incremental distance determined by the planned sequence and pattern required to give the desired specific properties.
    Type: Grant
    Filed: October 3, 1973
    Date of Patent: March 1, 1977
    Assignee: Albert L. Jeffers
    Inventor: Rexford H. Bradt