Patents by Inventor Robert Lee Rackley

Robert Lee Rackley 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: 6391240
    Abstract: Monofilaments with split ends. The monofilaments can be used to form toothbrush bristles having flagged or feathered tips. Each of the monofilaments has a plurality of internal fusion lines and at least four voids, wherein the voids comprise between 5 and 20% of the cross-sectional area of the monofilaments. Preferably, the monofilaments each have a diameter in a range of 0.0025 to 0.012 inches, and have a hexalocular or an octalocular configuration. The monofilaments are manufactured by extruding a plurality of thermoplastic polymeric streams, rotating a plurality of cutting blades above 1000 rpm, and placing a plurality of cutting blades in contact with end portions of the plurality of thermoplastic polymeric streams to form split ends.
    Type: Grant
    Filed: April 14, 1999
    Date of Patent: May 21, 2002
    Assignee: E.I. du Pont de Nemours and Company
    Inventor: Robert Lee Rackley
  • Patent number: 5939166
    Abstract: This invention provides moisture stable tuftstring carpet assemblies. The pile surface structure comprises a moisture stable backing substrate, a plurality of elongated pile articles each comprising an elongated, moisture stable support strand having bonded thereto a plurality of "U" shaped bundles of multifilament yarn. The pile articles are bonded to the backing substrate. Different backing substrates and support strands may be used.
    Type: Grant
    Filed: May 23, 1997
    Date of Patent: August 17, 1999
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Lap-Tak Andrew Cheng, Carmen Anoish Covelli, Robert Lee Rackley, Teh-Chuan Wang
  • Patent number: 5933906
    Abstract: Monofilaments with split ends. The monofilaments can be used to form toothbrush bristles having flagged or feathered tips. Each of the monofilaments has a plurality of internal fusion lines and at least four voids, wherein the voids comprise between 5 and 20% of the cross-sectional area of the monofilaments. Preferably, the monofilaments each have a diameter in a range of 0.0025 to 0.012 inches, and have a hexalocular or an octalocular configuration. The monofilaments are manufactured by extruding a plurality of thermoplastic polymeric streams, rotating a plurality of cutting blades above 1000 rpm, and placing a plurality of cutting blades in contact with end portions of the plurality of thermoplastic polymeric streams to form split ends.
    Type: Grant
    Filed: April 24, 1997
    Date of Patent: August 10, 1999
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Robert Lee Rackley
  • Patent number: 5849410
    Abstract: This invention relates to a coextruded monofilament having a sheath made of a first resin and a core made of a second resin which is different than the first resin and which has a higher coefficient of friction than the first resin. The core of the monofilament is exposed at the tip by conventional mechanical end-rounding techniques to form a tip with a higher coefficient of friction than the tip of a typical monofilament.
    Type: Grant
    Filed: December 12, 1996
    Date of Patent: December 15, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Charles Fletcher Nelson, Robert Lee Rackley
  • Patent number: 5770307
    Abstract: This invention relates to a coextruded monofilament having a core material made of a first resin and a sheath material made of a second resin, with the second resin being different from the first resin, and a pocket formed in the end of the monofilament. This invention also relates to a method of forming a pocket in the end of a coextruded monofilament by chemical or mechanical means, or a combination of chemical and mechanical means.
    Type: Grant
    Filed: September 27, 1996
    Date of Patent: June 23, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Robert Lee Rackley, Charles Fletcher Nelson
  • Patent number: 3962502
    Abstract: A process for curing a heat curable coating on a substrate is provided which is characterized by contacting one or both surfaces of the coated substrate with a patterned polyolefin film having a pattern height of at least 4 microns, followed by superposing the substrate and the patterned polyolefin film in alternating layers so as to provide an interleaf consisting of said patterned polyolefin film between adjacent layers of said substrate, and thereafter heating the superposed substrate and patterned polyolefin film at a temperature between about 25.degree.C. and the softening temperature of said patterned polyolefin film.
    Type: Grant
    Filed: December 12, 1974
    Date of Patent: June 8, 1976
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Robert Lee Rackley