Patents by Inventor Michael F. Durina

Michael F. Durina 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: 8734146
    Abstract: An improved automatic shutoff nozzle tip which is mounted on the downstream end of a nozzle body of an injection molding machine or the like who's purpose is to act as a passageway for molten plastic fluid allowing the fluid to flow in one direction when urged to open by the pressure created by the forward motion of the plasticizing screw of said molding machine and to close when said pressure is lower than the designed opening pressure. The nozzle, having an convex outwardly extended portion that mates up with a sprue bushing or mold having complimentary convex radii, said nozzle having a orifice on the distal end that mates with a complimentary orifice of said sprue bushing. A nozzle that has a means for attachment to a nozzle body or the like with a rear seat, poppet and spring or similar device who's poppet is normally in the closed position until pressure is applied urging the poppet to move in the downstream direction and providing for a passageway for molten plastic fluid.
    Type: Grant
    Filed: October 20, 2010
    Date of Patent: May 27, 2014
    Inventor: Michael F Durina
  • Publication number: 20120100245
    Abstract: An improved automatic shutoff nozzle tip which is mounted on the downstream end of a nozzle body of an injection molding machine or the like who's purpose is to act as a passageway for molten plastic fluid allowing the fluid to flow in one direction when urged to open by the pressure created by the forward motion of the plasticizing screw of said molding machine and to close when said pressure is lower than the designed opening pressure. The nozzle, having an convex outwardly extended portion that mates up with a sprue bushing or mold having complimentary convex radii, said nozzle having a orifice on the distal end that mates with a complimentary orifice of said sprue bushing. A nozzle that has a means for attachment to a nozzle body or the like with a rear seat, poppet and spring or similar device who's poppet is normally in the closed position until pressure is applied urging the poppet to move in the downstream direction and providing for a passageway for molten plastic fluid.
    Type: Application
    Filed: October 20, 2010
    Publication date: April 26, 2012
    Applicant: Md PLASTICS INCORPORATED
    Inventor: MICHAEL F. DURINA
  • Publication number: 20090117222
    Abstract: An improved precise control non-return valve assembly which is mounted on the front end of a helical rotating plasticating screw of an injection molding machine or the like that is surrounded by a heated elongated barrel and end-cap that forms a distribution chamber, whose purpose is to allow means for passage of molten plastic fluid in the downstream direction while preventing it in the opposite direction. The valve having an outwardly extended portion of a shaft and has a means to accept a ring that is sandwiched between a bushing assembly and a rear seating area. The bushing assembly consists of at least two bushings and one pin whose dual purpose is to govern the forward movement of the ring and to absorb the force that is being applied to it. The non-return valve assembly when moved forward with the screw, forms a seal, builds pressure, and displaces molten plastic fluid from the distribution chamber through a discharge chamber passageway and into a mold.
    Type: Application
    Filed: November 1, 2007
    Publication date: May 7, 2009
    Inventor: Michael F. Durina
  • Patent number: 7527493
    Abstract: An improved precise control non-return valve assembly which is mounted on the front end of a helical rotating plasticating screw of an injection molding machine or the like that is surrounded by a heated elongated barrel and end-cap that forms a distribution chamber, whose purpose is to allow means for passage of molten plastic fluid in the downstream direction while preventing it in the opposite direction. The valve having an outwardly extended portion of a shaft and has a means to accept a ring that is sandwiched between a bushing assembly and a rear seating area. The bushing assembly consists of at least two bushings and one pin whose dual purpose is to govern the forward movement of the ring and to absorb the force that is being applied to it. The non-return valve assembly when moved forward with the screw, forms a seal, builds pressure, and displaces molten plastic fluid from the distribution chamber through a discharge chamber passageway and into a mold.
    Type: Grant
    Filed: November 1, 2007
    Date of Patent: May 5, 2009
    Assignee: Md Plastics Incorporated
    Inventor: Michael F. Durina
  • Patent number: 6752528
    Abstract: A new plasticity apparatus including a rotating and reciprocating screw having a hellcal flight that is wrapped around a core, disposed within and cooperting with the inner wall of a heated barrel that substantially increases the melt quality of a polymeric material. This is accomplished by incorporating an increase in the hefix angle of the primary flight at the taper terminus of the transition section, in cooperation with a stepped change in the root that terminates either upstream or downstream of the end of one complete revolution of the flight.
    Type: Grant
    Filed: February 6, 2002
    Date of Patent: June 22, 2004
    Inventor: Michael F. Durina
  • Patent number: 6499987
    Abstract: An improved positive control non-return valve assembly which is mounted on the front end of a helical plasticating screw of an injection molding machine. The valve assembly comprises a thread retainer with means for attachment to the plasticating screw. The valve assembly also comprises a distribution chamber that has an annular shaped flow gap and a cylindrical passageway that leads to a plurality of discharge ports. The non-return valve assembly forms a seal, builds pressure, and displaces molten plastic fluid from the distribution chamber through a discharge chamber passageway, and into a mold.
    Type: Grant
    Filed: June 14, 2000
    Date of Patent: December 31, 2002
    Assignee: MD Plastics Incorporated
    Inventors: Michael F. Durina, Robert E. Tompkins
  • Patent number: 5816698
    Abstract: A plasticating apparatus including a rotating screw having a helical flight disposed within and cooperating with the inner wall of a heated barrel. Solid resinous material is introduced to a helical valley extending between said flight to be heated and plasticized by said apparatus while being advanced towards an outlet opening by the rotation of said screw. The screw has a meter section for working, melting and mixing said resinous material at high temperatures. The bottom surface of the helical valley in said metering section is divided into side by side relatively shallow and relatively deep levels. Within the metering section is a transit channel having a reverse helical direction as compared with the helical direction of the flight. Because of the reverse helical direction of the transit channel, the transit channel intersects the helical flight and helical valley with the transit channel cutting therethrough.
    Type: Grant
    Filed: April 15, 1996
    Date of Patent: October 6, 1998
    Assignee: Spirex Corporation
    Inventors: Michael F. Durina, Timothy W. Womer, Michael J. Senediak
  • Patent number: 5439633
    Abstract: An apparatus and method for controlling thermoplastic mixing in a plastic extrusion machines used for injection molding, blow molding or other reciprocating molding process. The plastic extruder having a rotating helical screw within a cylindrical shell with an automatic shut-off and mixing valve secured to the helical screw at the downstream end of the screw. The automatic shut-off and mixing valve includes a unitary valve body with a poppet. A plurality of mixing groove pairs are arranged extending substantially longitudinally on the surface of the valve body. Select angular bores extend from the groove pairs to the poppet. The poppet is axially movable within and rotatable relative the valve body. The poppet has an axial stem extending into a longitudinal axial bore within the valve body. An elastic means is positioned on the rearward end of the poppet maintaining the valve in a normally closed position against a seating surface of the valve body when there is no rotation of the helical screw.
    Type: Grant
    Filed: July 27, 1994
    Date of Patent: August 8, 1995
    Assignee: Spirex Corporation
    Inventors: Michael F. Durina, Shawn P. Bodnar, Timothy W. Womer
  • Patent number: 5188399
    Abstract: A pipe coupling device wherein the connection between pipe members is made by rotating one member relative to the other member so that a plurality of radially extending surfaces of one member face corresponding radially extending surfaces of the other member. The facing surfaces can be flat and planar. The plurality of facing flat surfaces initially face each other in an interlocking arrangement which is not tight. A single threaded adapter is then tightened to draw the plurality of facing surfaces of one member tightly against the corresponding facing surfaces of the other member.
    Type: Grant
    Filed: December 31, 1990
    Date of Patent: February 23, 1993
    Assignee: Spirex Corporation
    Inventor: Michael F. Durina
  • Patent number: 5164207
    Abstract: A plastic extruder having a rotating helical screw within a cylindrical shell. An automatic shut-off valve is mounted at the forward end of the helical screw. The valve includes a unitary or integral valve body and a poppet which is axially movable and is rotatable relative to the valve body. A rearwardly extending axial bore is provided at the forward end of the screw and the valve body extends into and is secured to the screw within said bore. The poppet has an axial stem which extends through the valve body into the axial bore. A compression spring is mounted on the rearward end of the poppet stem to act cooperatively with respect to the poppet to urge the poppet against a seating surface of the valve body and maintain the valve in a normally closed position. Flow of plastic through the valve upon rotation of the screw causes the valve to open. However, the valve automtically closes upon cessation of screw rotation to prevent back-flow of plastic during the injection step.
    Type: Grant
    Filed: November 8, 1991
    Date of Patent: November 17, 1992
    Assignee: Spirex Corporation
    Inventor: Michael F. Durina
  • Patent number: 5096302
    Abstract: A method and apparatus for regulating the flow of plastic particulates to the opening of a cylinder of a plasticating screw. The particulate pass through a feed throat disposed at a feed opening of the drum. A valve mechanism disposed in the feed throat includes upper and lower members connected by pivot means. A fulcrum is located below the pivot means and the lower member bears on the fulcrum. The upper member is moved up or down which in turn causes the lower member bearing on the fulcrum to swing about the pivot means to open or close the valve. As the valve is closed, the lower member moves downwardly towards the rotating screw to prevent flooding with particulates of the feed opening of the cylinder.
    Type: Grant
    Filed: April 24, 1991
    Date of Patent: March 17, 1992
    Assignee: Spirex Corporation
    Inventor: Michael F. Durina
  • Patent number: 4944906
    Abstract: Ionomers can be injection molded and extruded in wet condition using a vented, two-stage barrier screw wherein the barrier flight melt channel is operated only partially filled.
    Type: Grant
    Filed: October 11, 1988
    Date of Patent: July 31, 1990
    Assignee: Spirex Corporation
    Inventors: Paul N. Colby, Michael F. Durina