Patents by Inventor Thomas W. Winstead

Thomas W. Winstead 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: 5129728
    Abstract: A dynamic mixing system and method intensively mixes thermoplastic melt with other ingredients and entrains gas as a blowing agent in a thermoplastic melt so as to provide a foamed thermoplastic extrudate. The dynamic mixing system includes a plurality of mixing balls disposed circumferentially about the surface of a cylindrically shaped spindle which is rotatably disposed within a barrel, such that upon rotation of the spindle the mixing balls rotate in a planetary manner so as to intensively mix a flow of thermoplastic melt, for example, to entrain a blowing agent in the melt.
    Type: Grant
    Filed: August 29, 1991
    Date of Patent: July 14, 1992
    Inventor: Thomas W. Winstead
  • Patent number: 4518096
    Abstract: A drink-through lid for beverage containers is disclosed in which a pre-scored drink-through section is included which is removable by squeezing gripping surfaces on opposite sides of a score line which fractures the score line and permits the section to be pulled from the lid while causing the score to initiate a tearing action through the peripheral bead cavity of the lid to facilitate such removal. A continuous thermo-forming and scoring process and apparatus are provided to manufacture lids with scored sections having a predictable response to applied squeezing pressure on the gripping surfaces.
    Type: Grant
    Filed: May 12, 1983
    Date of Patent: May 21, 1985
    Assignee: Maryland Cup Corporation
    Inventor: Thomas W. Winstead
  • Patent number: 4487329
    Abstract: A tamper-evident closure for a container comprises a center portion for overlying an open portion of a container, a seal portion, and a circumferential line of weakness surrounding the seal portion and defining a circumferential tear-strip. At least the tear-strip comprises deformable material. The tear-strip comprises a portion which creates a separation therein upon deformation when the closure is secured to a container. A method for applying the closure to containers is also disclosed.
    Type: Grant
    Filed: October 13, 1983
    Date of Patent: December 11, 1984
    Assignee: Maryland Cup Corporation
    Inventor: Thomas W. Winstead
  • Patent number: 4436679
    Abstract: A method and apparatus for entraining gas as a blowing agent in a thermoplastic melt to provide a foamed thermoplastic extrudate wherein an annular sheet-like flow of gas under pressure is impinged on a tubular configuration of melt to entrain the gas in the melt is disclosed. Also disclosed is an improved method and apparatus for controlling the pressure in the thermoplastic melt.
    Type: Grant
    Filed: November 9, 1981
    Date of Patent: March 13, 1984
    Assignee: Maryland Cup Corporation
    Inventor: Thomas W. Winstead
  • Patent number: 4421712
    Abstract: Methods and apparatus are provided for pressure and/or plug assist and match molding configurations for in-line continuous rotary thermo-forming systems. The pressure assist, plug assist and matched mold devices are carried on continuous endless loop indexing structures which accurately index them with the mold cavities in respective rotary mold wheels to achieve high thermo-forming speeds without loss of quality in the ultimate products. The drives of the continuous endless loop indexing structures are synchronized with those of the mold wheel. The systems are continuous ones in which the webs to be thermo-formed are continuously extruded and from which the thermo-formed products are continuously cut and stacked downstream of the rotary mold wheel, with the web selvage being returned and recycled into the extrusion device.
    Type: Grant
    Filed: August 13, 1980
    Date of Patent: December 20, 1983
    Assignee: Maryland Cup Corporation
    Inventor: Thomas W. Winstead
  • Patent number: 4420300
    Abstract: Apparatus for continuous thermoforming of sheet material including an extruder, stretching means, a rotary wheel having female mold means thereon and plural plug-assist means interlinked so as to form an orbiting device having the plug-assist members engaging the sheet material about a substantial arc of wheel surface and means to reciprocate the plug assist members into and out of engagement with the female mold means.
    Type: Grant
    Filed: April 20, 1982
    Date of Patent: December 13, 1983
    Assignee: Maryland Cup Corporation
    Inventor: Thomas W. Winstead
  • Patent number: 4420291
    Abstract: A dynamic cooler apparatus is provided for dynamically cooling molten plastic extrudate while pumping metered amounts of that extrudate to an extrusion die or the like. The dynamic cooler apparatus utilizes bi-helical gears in a gear pump configuration in a housing in which a heat exchange medium is circulated. The heat exchange medium is also circulated internally of the gears so that the gear teeth and the housing act to cool discrete volumes of extrudate from four sides defined by the gear teeth and the internal surface of the housing. The bi-helical gears are driven to minimize loading between the teeth thereof and to permit the teeth to be as small as practical to present more cooling surface for a given cross-section of extrudate and optimize the heat transfer capability of the dynamic cooler apparatus. Provision is also made to use the molten extrudate as a lubricant for the shafts and bearings of the bi-helical gears.
    Type: Grant
    Filed: January 5, 1979
    Date of Patent: December 13, 1983
    Assignee: Maryland Cup Corporation
    Inventor: Thomas W. Winstead
  • Patent number: 4416607
    Abstract: An apparatus for continuously extruding, biaxially orienting and intermittently forming molded products from a web of thermoplastic material and further, continuously separating the products from the web selvage, stacking and handling the products and recycling the web selvage for further extrusion. The apparatus uses intermittent molding and biaxial orientation devices into which configuration the continuously extruded web is interfaced by continuous-to-intermittent interfacing loop arrangement which preserves the dimensional and orientational integrity of the web and maintains sufficient thermal stability therein to provide molded products which are free from defects such as stretch marks and other inertial and thermal discontinuities normally anticipated in cases of intermittent web advance of thermoplastic material at thermoformalbe temperature levels.
    Type: Grant
    Filed: June 15, 1981
    Date of Patent: November 22, 1983
    Assignee: Maryland Cup Corporation
    Inventor: Thomas W. Winstead
  • Patent number: 4413964
    Abstract: An apparatus for continuously extruding, biaxially orienting and forming molded products from a web of thermoplastic material and further, continuously separating the products from the web selvage, stacking and handling the products and recycling the web selvage for further extrusion. The apparatus use continuous molding devices, namely, multiple mold cavities in a rotating polygon configuration over the peripheral surface of which the biaxially oriented web is securely and continuously positioned by a follower roller interfacing the polygon with a biaxial orientation device. Continuous and immediate interfacing is effected to prevent loss of orientation in the web which is kept at a temperature suitable for ingestion thereof into the mold cavities by vacuum, pressure or plug assist. In one preferred embodiment the inertia at the interface between the undulating peripheral surface of the rotating mold polygon and biaxial orientation apparatus is reduced to an optimal minimum.
    Type: Grant
    Filed: May 29, 1980
    Date of Patent: November 8, 1983
    Assignee: Maryland Cup Corporation
    Inventor: Thomas W. Winstead
  • Patent number: 4384836
    Abstract: An apparatus for continuously extruding, biaxially orienting and intermittently forming molded products from a web of thermoplastic material and further, continuously separating the products from the web selvage, stacking and handling the products and recycling the web selvage for further extrusion. The apparatus uses intermittent molding devices into which configuration the biaxially oriented web is interfaced by a continuous-to-intermittent interfacing structure which preserves the dimensional and orientational integrity of the web and maintains thermal stability therein. An undulating peripheral surface on a dynamic storage or accumulator drum and associated transfer rollers cooperate with intermittently advanced feed belts in timed relationship with a reciprocating forming press to effectuate the interface and product forming portions of the process.
    Type: Grant
    Filed: May 29, 1980
    Date of Patent: May 24, 1983
    Assignee: Maryland Cup Corporation
    Inventor: Thomas W. Winstead
  • Patent number: 4307049
    Abstract: A method for continuously extruding, biaxially orienting and intermittently forming molded products from a web of thermoplastic material and further, continuously separating the products from the web selvage, stacking and handling the products and recycling the web selvage for further extrusion. The method uses intermittent molding and biaxial orientation devices into which configuration the continuously extruded web is interfaced by continuous-to-intermittent interfacing loop arrangement which preserves the dimensional and orientational integrity of the web maintains sufficient thermal stability therein to provide molded products which are free from defects such as stretch marks and other inertial and thermal discontinuities normally anticipated in cases of intermittent web advance of thermoplastic material at thermoformable temperature levels.
    Type: Grant
    Filed: February 1, 1980
    Date of Patent: December 22, 1981
    Assignee: Maryland Cup Corporation
    Inventor: Thomas W. Winstead
  • Patent number: 4288400
    Abstract: A method and apparatus for continuously extruding, biaxially orienting and intermittently forming molded products from a web of thermoplastic material and further, continuously separating the products from the web selvage, stacking and handling the products and recycling the web selvage for further extrusion. The method and apparatus use intermittent molding devices into which configuration the biaxially oriented web is interfaced by a continuous-to-intermittent interfacing structure which preserves the dimensional and orientational integrity of the web and maintains thermal stability therein. An undulating peripheral surface on a dynamic storage or accumulator drum and associated transfer rollers cooperate with intermittently advanced feed belts in timed relationship with a reciprocating forming press to effectuate the interface and product forming portions of the process.
    Type: Grant
    Filed: March 13, 1978
    Date of Patent: September 8, 1981
    Assignee: Maryland Cup Corporation
    Inventor: Thomas W. Winstead
  • Patent number: 4250129
    Abstract: A method and apparatus for continuously extruding, biaxially orienting and forming molded products from a web of thermoplastic material and further, continuously separating the products from the web selvage, stacking and handling the products and recycling the web selvage for further extrusion. The method and apparatus use continuous molding devices, namely, multiple mold cavities in a rotating polygon configuration over the peripheral surface of which the biaxially oriented web is securely and continuously positioned by a follower roller interfacing the polygon with a biaxial orientation device. Continuous and immediate interfacing is effected to prevent loss of orientation in the web which is kept at a temperature suitable for ingestion thereof into the mold cavities by vacuum, pressure or plug assist. In one preferred embodiment the inertia at the interface between the undulating peripheral surface of the rotating mold polygon and the biaxial orientation apparatus is reduced to an optimal minimum.
    Type: Grant
    Filed: March 13, 1978
    Date of Patent: February 10, 1981
    Assignee: Maryland Cup Corporation
    Inventor: Thomas W. Winstead
  • Patent number: 4115273
    Abstract: An extracorporeal, disposable, dialyzer for use in a variety of artificial kidney or other mass transfer systems, which includes a sheet of plastic material supporting a flattened tube of membrane material, the sheet of support material consists of a continuous sheet of contoured, substantially uniform thickness material including a series of spaced apart hollow protrusions extending outwardly from each side thereof, the summits of the hollow protrusions defining membrane support surfaces on each side of the sheet, and the summits being arranged with respect to each other in predetermined wave patterns dimensioned and arranged such that, when an elongated length of the sheet is formed into a roll having predetermined inner and outer peripheral dimensions, the wave patterns will never be directly superimposed thereby avoiding the tendency of corresponding hollow protrusions to interdigitate and occlude the fluid flow passages.
    Type: Grant
    Filed: November 15, 1976
    Date of Patent: September 19, 1978
    Assignee: Extracorporeal Medical Specialties, Inc.
    Inventor: Thomas W. Winstead