Patents by Inventor Ray F. Stewart

Ray F. Stewart 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: 6199318
    Abstract: Crystalline polymers are prepared as a latex, and are useful for coating fibrous materials such hair and fabrics. The latex can have a high solids content greater than 30%, a residual monomer content of less than 1%, and can be used for repeatedly setting fibrous materials into desired configurations. The latex is also useful for coating organisms such as seeds. The particulate coating extends the dormancy of the organism and/or protects the organism, and is easily shed by a germinating seed. The coating can contain a seed coating additive, such as a colorant or fungicide.
    Type: Grant
    Filed: September 15, 1997
    Date of Patent: March 13, 2001
    Assignee: Landec Corporation
    Inventors: Ray F. Stewart, Natarajan Balachander, Steven P. Bitler, Loc Phan, Valentine Y. Yoon
  • Patent number: 5807291
    Abstract: Orthopedic casts which comprise an elastically deformed support which is held in its elastically deformed state by a solid casting composition. After the cast has been placed around a patient's limb, it is heated to soften the casting composition, thus permitting recovery of the cast into conforming contact with the limb. The support can for example be a fabric knitted from elastomeric fibers and glass fiber yarns. The casting composition can for example comprise polycaprolactone and/or a side chain crystallizable polymer, which melts at 45.degree.-60.degree. C. A padded liner can be placed between the cast and the limb. Recovery of the cast is preferably carried out by means of a hot air gun.
    Type: Grant
    Filed: May 25, 1995
    Date of Patent: September 15, 1998
    Inventors: Andrew W. Larson, Steven P. Bitler, Lawrence C. Greene, David D. Taft, Ray F. Stewart, Valentine Y. Yoon, Thomas W. Ross, David A. Kamp, Edward E. Schmitt
  • Patent number: 5783302
    Abstract: TPE's which comprise A blocks or B blocks or both A blocks and B blocks, which are crystalline and in which at least a part of the crystallinity result from the presence of crystallizable side chains. Such crystalline blocks are referred to as SCC blocks. TPE's containing SCC A blocks are novel and as such form part of the present invention. The invention also includes processes, compositions, shaped articles and assemblies which make use of TPE's containing SCC A blocks.
    Type: Grant
    Filed: May 22, 1995
    Date of Patent: July 21, 1998
    Assignee: Landec Corporation
    Inventors: Steven P. Bitler, Raymond Clarke, David A. Kemp, Ray F. Stewart, Valentine Y. Yoon, Robert G. Freelin
  • Patent number: 5752926
    Abstract: Orthopedic casts which comprise an elastically deformed support which is held in its elastically deformed state by a solid casting composition. After the cast has been placed around a patient's limb, it is heated to soften the casting composition, thus permitting recovery of the cast into conforming contact with the limb. The support can for example be a fabric knitted from elastomeric fibers and glass fiber yarns. The casting composition can for example comprise polycaprolactone and/or a side chain crystallizable polymer, which melts at 45.degree.-60.degree. C. A padded liner can be placed between the cast and the limb. Recovery of the cast is preferably carried out by means of a hot air gun.
    Type: Grant
    Filed: November 9, 1993
    Date of Patent: May 19, 1998
    Assignee: Landec Corporation
    Inventors: Andrew W. Larson, Steven P. Bitler, Lawrence C. Greene, David D. Taft, Ray F. Stewart, Valentine Y. Yoon, Thomas W. Ross, David A. Kamp, Edward E. Schmitt
  • Patent number: 5665822
    Abstract: Thermoplastic elastomers (TPEs) containing side chain crystalline (SCC) blocks. The SCC blocks my be hard (A) blocks or the soft (B) blocks (or both) in the TPE. Some of these TPEs are novel, e.g. those in which A blocks are SCC blocks, and the B blocks are polyethers, polyacrylates, polyamides, polyurethanes or polysiloxanes. The SCC-containing TPEs are particularly useful as matrix materials for other components which are dispersed therein, e.g. energetic solids and other thermally responsive materials.
    Type: Grant
    Filed: April 14, 1993
    Date of Patent: September 9, 1997
    Assignee: Landec Corporation
    Inventors: Steven P. Bitler, Ray F. Stewart, David A. Kamp, Robert G. Freelin, Valentine Y. Yoon
  • Patent number: 5387450
    Abstract: Temperature-activated adhesive compositions formulated with crystallizable polymers are provided. The compositions, which display a rapid transition from the tacky to the nontacky state, and/or from the nontacky to the tacky state, are useful in medical applications, where adhesion of a substrate to the skin is desired, as well as in a variety of nonmedical applications. Temperature-activated adhesive assemblies such as tapes, labels, and the like for use in a number of contexts are provided which assemblies have a moisture vapor transmission rate which is compatible with human skin, e.g., above 500 g/m.sup.2 /day at 37.degree. C. and a 100% to 10% relative humidity difference.
    Type: Grant
    Filed: February 27, 1992
    Date of Patent: February 7, 1995
    Assignee: Landec Corporation
    Inventor: Ray F. Stewart
  • Patent number: 5382909
    Abstract: Detection of liquid leaks and other changes in variables is disclosed. The event causes two elongate conductors to become electrically connected at a location which is determined by the event, thus creating a system in which the connection point can be located by measuring the potential drop from one end of one of the conductors (called the locating member) to the connection point. The system comprises a balancing component so that its sensitivity is not dependent on the location of the event along an elongate path. A fixed current flows through the connection, so that the result is independent of the resistance of the connection. The locating member can be a continuous resistive wire, coated with a conductive polymer; such a locating member can form part of a sensor cable in which the elongate components of the circuit are in a wrapped configuration. Alternatively the locating member comprises a plurality of discrete resistors.
    Type: Grant
    Filed: July 30, 1993
    Date of Patent: January 17, 1995
    Assignee: Raychem Corporation
    Inventors: Michael Masia, James P. Reed, Robert S. Wasley, Larry R. Reeder, Peter L. Brooks, Thomas W. Tolles, Louis M. Frank, Mauro Bonomi, Ray F. Stewart, John Lahlough, Laurence Welsh
  • Patent number: 5254354
    Abstract: Food may be packaged and preserved for extended periods using intelligent polymers formed into food containers which have specific and variable gas permeabilities. The polymers used in forming the food packages are intelligent in that they have permeabilities which may be radically and reversibly changed by relatively small changes in temperature. By using different types and formulations of polymers and various temperatures, it is possible to create an environment within the food package which adjusts to the respiration of the food so as to best preserve the color, quality and/or shelf life of the food. The polymers are side-chain crystallizable polymers designed and formulated so as to provide a material which is substantially impermeable to a gas such as oxygen, carbon dioxide or water vapor at a temperature below a given phase transition point and permeable to the same gas at a temperature above that point.
    Type: Grant
    Filed: May 18, 1992
    Date of Patent: October 19, 1993
    Assignee: Landec Corporation
    Inventor: Ray F. Stewart
  • Patent number: 5235286
    Abstract: An elongate sensor for detecting and locating presence of a liquid, e.g. water or a hydrocarbon. The sensor includes first and second elongate members which are spaced apart from each other and each of which is a metal conductor covered by a conductive polymer; a third, insulated elongate conductor; and an elongate insulating core. At least one of the elongate members is helically wrapped around the core. Presence of the liquid at any point along the length of the sensor causes the first and second members to be electrically connected at that point, creating a system in which the potential drop down one of the members can be measured and the location of the connection determined.
    Type: Grant
    Filed: May 9, 1991
    Date of Patent: August 10, 1993
    Assignee: Raychem Corporation
    Inventors: Michael Masia, James P. Reed, Robert S. Wasley, Larry R. Reeder, Peter L. Brooks, Thomas W. Tolles, Louis M. Frank, Mauro Bonomi, Ray F. Stewart, John Lahlough, Lawrence Welsh
  • Patent number: 5156911
    Abstract: An adhesive assembly is provided having a temperature-sensitive adhesive composition coated on the surface of a selected substrate. The adhesive composition is nontacky or slightly tacky at room temperature, but is aggressively tacky at skin temperature. The assemblies include adhesive tapes, bandages, films and the like.
    Type: Grant
    Filed: May 11, 1989
    Date of Patent: October 20, 1992
    Assignee: Landec Labs Inc.
    Inventor: Ray F. Stewart
  • Patent number: 5129180
    Abstract: Coated organisms and particularly coated seeds are provided wherein the coating is comprised of one or more polymeric materials which form a coating having a temperature-dependent permeability with respect to a material such as water permeability. The polymeric materials used in making the coatings are relatively impermeable to the material such as water at cooler temperatures (less than optimum growth or germination temperatures) and relatively permeable at higher temperatures (at or greater than optimum growth or germination temperatures). The variable permeability of the coating prevents imbibition at lower temperatures and allows it at higher temperatures. Accordingly, coated seeds can be planted early in a planting season and undergo imbibition followed by germination under favorable moisture and temperature conditions.
    Type: Grant
    Filed: December 7, 1990
    Date of Patent: July 14, 1992
    Assignee: Landec Labs, Inc.
    Inventor: Ray F. Stewart
  • Patent number: 5120349
    Abstract: The microcapsules of the invention are comprised of crystallizable polymers which are preferably side-chain crystallizable polymers or cross-linked, side-chain crystallizable polymers having a specific first order transition point or "melt" temperature. The polymers are caused to form microcapsules and thereby encapsulate one or more compounds generally referred to herein as an active ingredient such as a herbicide, insecticide, fungicide, or fertilizer. The polymer of the microcapsule surrounds the active ingredient separating it from the outside environment. Crystallizable polymers used herein have temperature-dependent permeabilities with respect to a given component such that this component is kept out of contact with the active ingredient at a temperature below a given first order transition point and (due to increased permeability) is allowed to contact the active ingredient at a temperature at or above the transition point.
    Type: Grant
    Filed: December 7, 1990
    Date of Patent: June 9, 1992
    Assignee: Landec Labs, Inc.
    Inventors: Ray F. Stewart, Lawrence C. Greene, Ravi K. Bhaskar
  • Patent number: 5101657
    Abstract: Devices for detecting and obtaining information about an event, for example the presence of a liquid, which comprise (1) a swellable member which swells upon occurrence of the event and (2) a restraining member which, when the swellable member swells, restricts movement of the swellable member and thus causes the impedance of the device to change. In a preferred embodiment the device comprises two elongate conductors helically wrapped around a support core, a swellable, conductive polymer member surrounding the conductors. Occurrence of an event causes the swellable material to swell and form a conductive bridge between the conductors.
    Type: Grant
    Filed: May 7, 1990
    Date of Patent: April 7, 1992
    Assignee: Raychem Corporation
    Inventors: John Lahlouh, Ray F. Stewart, Robert S. Wasley, Paul D. Hauptly, Laurence M. Welsh
  • Patent number: 5074988
    Abstract: An electrode, preferably of a conductive polymer, has on its surface, preferably over all of its surface, an ion exchange material, preferably of significant thickness. Such a coated electrode may be used for sensing the presence of measuring the concentration of an ionic species, or for removal from or release of an ionic species into an electrode.
    Type: Grant
    Filed: May 14, 1990
    Date of Patent: December 24, 1991
    Assignee: Raychem Corporation
    Inventors: Eric D. Nyberg, Ken A. Klingman, Jeff Curtis, Ray F. Stewart
  • Patent number: 5049247
    Abstract: A method for monitoring for the presence of an electrolyte and for locating the electrolyte upon its presence uses a system comprising an electrically conductive locating member and an electrically conductive source member, between which an electrical connection is made upon the presence of the electrolyte. The locating member and/or the source member comprises (i) an electrode and (ii) an ion exchange material which is in electrical and physical contact with and substantially entirely surrounds all surfaces of the electrode; the ion exchange material having an ionic resistance which depends upon the concentration of a chemical species in the electrolyte. Upon the presence of the electrolyte, a connection to the locating member is made effective at a first point whose location is defined by the presence of the electrolyte.
    Type: Grant
    Filed: October 17, 1989
    Date of Patent: September 17, 1991
    Assignee: Raychem Corporation
    Inventors: Eric D. Nyberg, Ken A. Klingman, Jeff Curtis, Ray F. Stewart
  • Patent number: 5045163
    Abstract: An electrode, preferably of a conductive polymer, has on its surface, preferably over all of its surface, an ion exchange material, preferably of significant thickness. Such a coated electrode may be used for sensing the presence or measuring the concentration of an ionic species, or for removal from or release of an ionic species into an electrode.
    Type: Grant
    Filed: June 5, 1990
    Date of Patent: September 3, 1991
    Assignee: Raychem Corporation
    Inventors: Eric D. Nyberg, Ken A. Klingman, Jeff Curtis, Ray F. Stewart
  • Patent number: 5019235
    Abstract: An electrode, preferably of a conductive polymer, has on its surface, preferably over all of its surface, an ion exchange material, preferably of significant thickness. Such a coated electrode may be used for sensing the presence or measuring the concentration of an ionic species, or for removal from or release of an ionic species into an electrode.
    Type: Grant
    Filed: February 1, 1990
    Date of Patent: May 28, 1991
    Assignee: Raychem Corporation
    Inventors: Eric D. Nyberg, Ken A. Klingman, Jeff Curtis, Ray F. Stewart
  • Patent number: 5015958
    Abstract: Detection of events, e.g. liquid leaks and other changes in varibles. The event causes two conductors to become electrically connected, and thus creating a system in which the connection point can be located by measuring the potential drop from one end of one of the conductors (called the locating member) to the connection point. Preferably a fixed current flows through the connection, so that the result is independent of the resistance of the connection. The locating member can be a continuous resistive wire, preferably coated with a conductive polymer; such a locating member can form part of a sensor cable in which the elongate components of the circuit are in a wrapped configuration, or part of a cable in which the conductors are separated by a member shaped to prevent capillary action of a liquid from connecting the conductors. Alternatively the locating member comprises a plurality of discrete resistors.
    Type: Grant
    Filed: June 27, 1989
    Date of Patent: May 14, 1991
    Assignee: Raychem Corporation
    Inventors: Michael Masia, James P. Reed, Robert S. Wasley, Paul D. Hauptly, Larry R. Reeder, Peter L. Brooks, Thomas W. Tolles, Louis M. Frank, Mauro Bonomi, Denis Wales, Ray F. Stewart, John Lahlouh, Laurence Welsh
  • Patent number: 5007989
    Abstract: An electrode, preferably of a conductive polymer, has on its surface, preferably over all of its surface, an ion exchange material, preferably of significant thickness. Such a coated electrode may be used for sensing the presence or measuring the concentration of an ionic species, or for removal from or release of an ionic species into an electrode.
    Type: Grant
    Filed: October 17, 1989
    Date of Patent: April 16, 1991
    Assignee: Raychem Corporation
    Inventors: Eric D. Nyberg, Ken A. Klingman, Jeff Curtis, Ray F. Stewart
  • Patent number: 4990231
    Abstract: Methods of preventing corrosion in which current flows between the to-be-protected substrate and a distributed electrode whose electrochemically active surface is provided by an element which is composed of a conductive polymer and which is at least 500 microns thick. In one embodiment, the electrode is a flexible strip comprising a highly conductive core. e.g. of copper, and a conductive polymer element surrounding the core. In another embodiment, the electrode is a conductive polymer layer which conforms to the surface of the substrate but is separated from it by a layer of insulation.
    Type: Grant
    Filed: January 26, 1990
    Date of Patent: February 5, 1991
    Assignee: Raychem Corporation
    Inventors: Ray F. Stewart, Michael Masia, Albert B. Macknick