Patents by Inventor Chang-Hee Choi

Chang-Hee Choi 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).

  • Publication number: 20130302099
    Abstract: A hexahedral insert has top and bottom faces and two pairs of opposing side faces with main cutting edges formed on the borders of the top and bottom faces to the side faces and a screw hole passing through each central portion of the top and bottom faces. The top and bottom faces are flat planes parallel to each other; each of the side faces consecutively from top to bottom includes an upper land portion, an upper inwardly-inclined portion, a flat support surface, a lower inwardly-inclined portion, and a lower land portion. Each of two adjacent side faces has a corner surface therebetween which forms corner edges on the borders to the top and bottom faces. The cutting insert enhances the cutting power by reducing cutting resistance and prevents scratches on a machined surface.
    Type: Application
    Filed: July 19, 2013
    Publication date: November 14, 2013
    Applicant: TAEGUTEC LTD.
    Inventors: Chang Hee CHOI, Chang Gyu Park, Jae Wook Lee
  • Patent number: 8556548
    Abstract: A clamp fastens a cutting insert to a tool holder. The clamp assembly includes a body portion provided with a screw hole, a forward protrusion formed at the front portion of the body and extending downward, a rear protrusion formed at the rear end portion of the body and extending downward, and a bridge connecting the forward protrusion and the central portion of the body. The clamp assembly also includes a pressing plate having upper and lower surfaces, a front nose portion, a rear end portion, and is provided with a keyhole shaped groove having an enlarged inner cavity open toward the rear end by a narrow neck extending thicknesswise. The forward protrusion is inserted into the enlarged inner cavity and the bridge is inserted into the narrow neck of the keyhole groove so that the pressing plate is coupled to the clamp.
    Type: Grant
    Filed: September 12, 2011
    Date of Patent: October 15, 2013
    Assignee: TaeguTec, Ltd.
    Inventors: Hong Sik Park, Sung Hyup Park, Chang Hee Choi
  • Patent number: 8469637
    Abstract: A cutting insert has an upper face and a lower face; a front side face portion and a back side face portion, the front and back side face portions connecting the upper face and the lower face; and a through-hole passing through the upper face and the lower face. A cutting edge is formed in the front side face portion, and the back side face portion is provided with a first inclined face and a second inclined face which are inclined forwardly at different angles, respectively, with respect to a plane normal to a rotational axis. The first inclined face is longer than the second inclined face so that the back side face portion has a non-symmetrical convex ā€œVā€ shape.
    Type: Grant
    Filed: August 22, 2011
    Date of Patent: June 25, 2013
    Assignee: TaeguTec, Ltd.
    Inventors: Chang Hee Choi, Chang Gyu Park, Hee-Seok Kim
  • Patent number: 8434975
    Abstract: A double-sided milling cutting insert has usable upper and lower faces. The upper face has a polygonal shape with curved edges. The lower face has a rotationally symmetrical relation to the upper face. Flank faces connect edges of the upper face to corresponding edges of the lower face. Upper cutting edges are formed on one of the edges of the upper face. The upper chip-forming portions have rake faces inclined downwardly from the upper cutting edges inwardly of the cutting insert and a plurality of protrusions arranged along inner boundaries of the rake faces for deflecting chips. When the cutting insert is mounted on the cutting tool, a width of the rake face of the upper chip-forming portion adjacent to an edge portion forming a main cutting edge gradually increases in a direction going away from a rotational axis of the cutting tool.
    Type: Grant
    Filed: February 16, 2007
    Date of Patent: May 7, 2013
    Assignee: TaeguTec, Ltd.
    Inventors: Chang Hee Choi, Chang Gyu Park
  • Publication number: 20130058729
    Abstract: A cutting tool includes a cutting insert and a tool holder. The tool holder includes: a base for supporting a bottom surface of the cutting insert; a clamping arm for pressing a top surface of the cutting insert; an insert receiving space formed between the bottom surface of the clamping arm and the base; and a supporting surface which defines an end of the insert receiving space and supports an end of the cutting insert. The cutting insert includes: a first pressing region on the front portion of the top surface which is oriented in a vertically upward direction; and a second pressing region on the rear portion of the top surface which is oriented at an angle in the front direction.
    Type: Application
    Filed: February 10, 2010
    Publication date: March 7, 2013
    Applicant: TaeguTec, Ltd.
    Inventors: Chang Hee Choi, Hong Sik Park
  • Patent number: 8328472
    Abstract: A cutting insert of the present invention has a body, auxiliary cutting edges of a convex curve shape and main cutting edges. The body has a top surface, a bottom surface, side surfaces connecting the top and bottom surfaces, and corner surfaces connecting the adjacent side surfaces. The auxiliary cutting edges are formed at intersections between the top and bottom surfaces and the side surfaces. The main cutting edges are formed at intersections between the top and bottom surfaces and the corner surfaces. The main cutting edge in the top surface extends from an end of an adjacent auxiliary cutting edge to its center in a direction toward the bottom surface and from the center to an end of another adjacent auxiliary cutting edge in a direction away from the bottom surface.
    Type: Grant
    Filed: August 30, 2007
    Date of Patent: December 11, 2012
    Assignee: TaeguTec, Ltd.
    Inventors: Chang Hee Choi, Chang Gyu Park
  • Publication number: 20120308317
    Abstract: A cutting insert has top and bottom surfaces in the thicknesswise direction, and front and rear surfaces in the widthwise direction. First and second cutting edges are formed in the lengthwise direction at intersection portions where the top surface intersects with the front and rear surfaces. Third and fourth cutting edges are formed in the lengthwise direction at intersection portions where the bottom surface intersects with the front and rear surfaces. The first to fourth cutting edges are divided by a plurality of recesses. The plurality of recesses are symmetric with respect to the lengthwise centerline (A), which runs between the first and third cutting edges on the front surface and are asymmetric with respect to the thicknesswise centerline (B) perpendicular to the lengthwise centerline (A).
    Type: Application
    Filed: February 18, 2011
    Publication date: December 6, 2012
    Applicant: TAEGUTEC, LTD.
    Inventors: Chang Hee Choi, Chang Gyu Park
  • Publication number: 20120282047
    Abstract: An internal groove insert includes a rectangular main body having a top surface, a lower surface, and first to fourth lateral surfaces; and first and second projections each projecting from the adjacent first and second lateral surfaces. The first projection has a first cutting edge at the side of the top surface of the main body, while the second projection has a second cutting edge at the side of the lower surface. The first and fourth lateral surfaces are inclined by an obtuse angle with respect to the top surface, while the second and third lateral surfaces are inclined by an acute angle with respect to the top surface. The central axis of the clamping hole is inclined to be parallel to the insert corner edge where the first and fourth lateral surfaces meet.
    Type: Application
    Filed: February 9, 2010
    Publication date: November 8, 2012
    Inventors: Chang Hee Choi, Hong Sik Park, Sung Hyup Park
  • Publication number: 20120162880
    Abstract: Discussed is a display apparatus which facilitates to minimize a thickness by innovatively removing a case and some portions of a set cover, which have been regarded as indispensible structures for the display apparatus, and simultaneously facilitates to realize a good sense of beauty in the display apparatus by a novel design, wherein the display apparatus comprises a set cover which has a space prepared by a sidewall; a display panel which includes lower and upper substrates bonded to each other; and a guide frame which supports the display panel, and seals a gap between a sidewall of the set cover and a lateral side of the display panel, wherein the guide frame is provided in the set cover.
    Type: Application
    Filed: December 19, 2011
    Publication date: June 28, 2012
    Inventors: Kyoung Sang YOON, Kyung Jae Park, Chang Hee Choi
  • Publication number: 20120141215
    Abstract: A multi-functional cutting tool can be used for a turning process as well as a drilling process. The multi-functional cutting tool includes: a shank having a flat surface to be fixed to a cutting device; first and second cutting portions of cylindrical shape, each of which extends from the respective ends of the shank; and a cooling hole straightly extending and penetrating into the cutting tool from the end of the first cutting portion to the end of the second cutting portion in a direction of the rotational axis of the cutting tool.
    Type: Application
    Filed: January 12, 2010
    Publication date: June 7, 2012
    Applicant: TaeguTec, Ltd.
    Inventors: Chang Hee Choi, Hong Sik Park, Chul Ho Lee
  • Publication number: 20120093595
    Abstract: A cutting tool for machining large workpieces having relatively a large cutting amount and a cutting insert configured to be used with the cutting tool. The cutting tool includes a cutting insert and a wedge for clamping the cutting insert. The cutting insert has a polygonal top surface, which comprises a recessed portion having a plurality of inclined abutment surfaces which are inclined toward the center of the top surface. The outline of said recessed portion is twisted at a predetermined angle with respect to the outline of the top surface. The wedge includes a projecting portion that contacts the inclined abutment surface and pushes the cutting insert so that two side surfaces of the cutting insert can be supported by a radial inner side surface and a lateral supporting surface of an insert seat.
    Type: Application
    Filed: June 24, 2009
    Publication date: April 19, 2012
    Applicant: TAEGU TEC, LTD.
    Inventor: Chang Hee Choi
  • Publication number: 20120070242
    Abstract: A cutting insert has a top surface, a bottom surface, a plurality of side surfaces that connect the top and bottom surfaces. The side surfaces form an obtuse angle with the bottom surface as well as an acute angle with the top surface. The side surfaces include a first side surface and a second side surface, which form an obtuse angle with each other when seen from the above. A main cutting edge is formed at an intersection between the first side surface and the top surface. An inclined cutting edge, which is only for ramp milling, and a minor cutting edge are formed at an intersection between the second side surface and the top surface. An obtuse angle, which the second side surface forms with the bottom surface, is greater than that which the first side surface forms with the bottom surface.
    Type: Application
    Filed: June 26, 2009
    Publication date: March 22, 2012
    Applicant: TaeguTec, Ltd.
    Inventors: Chang Hee Choi, Chang Gyu Park, Sung Pil Choi
  • Publication number: 20120051852
    Abstract: A cutting tool includes one or more cutting portions. Each of the cutting portions has a cutting insert and an insert pocket for mounting the cutting insert. The insert pocket has a top surface with one or more projecting portions with a shape of serration, and a bottom supporting surface. The cutting insert has a top surface mating with said projecting portions of the insert pocket, and a bottom surface mating with the bottom supporting surface of the insert pocket.
    Type: Application
    Filed: June 10, 2009
    Publication date: March 1, 2012
    Applicant: Taegu Tec, Ltd.
    Inventors: Chang Hee Choi, Chang Gyu Park
  • Publication number: 20120003053
    Abstract: A clamp fastens a cutting insert to a tool holder. The clamp assembly includes a body portion provided with a screw hole, a forward protrusion formed at the front portion of the body and extending downward, a rear protrusion formed at the rear end portion of the body and extending downward, and a bridge connecting the forward protrusion and the central portion of the body. The clamp assembly also includes a pressing plate having upper and lower surfaces, a front nose portion, a rear end portion, and is provided with a keyhole shaped groove having an enlarged inner cavity open toward the rear end by a narrow neck extending thicknesswise. The forward protrusion is inserted into the enlarged inner cavity and the bridge is inserted into the narrow neck of the keyhole groove so that the pressing plate is coupled to the clamp.
    Type: Application
    Filed: September 12, 2011
    Publication date: January 5, 2012
    Applicant: TaeguTec, Ltd.
    Inventors: Hong Sik Park, Sung Hyup Park, Chang Hee Choi
  • Publication number: 20110299945
    Abstract: A cutting insert has an upper face and a lower face; a front side face portion and a back side face portion, the front and back side face portions connecting the upper face and the lower face; and a through-hole passing through the upper face and the lower face. A cutting edge is formed in the front side face portion, and the back side face portion is provided with a first inclined face and a second inclined face which are inclined forwardly at different angles, respectively, with respect to a plane normal to a rotational axis. The first inclined face is longer than the second inclined face so that the back side face portion has a non-symmetrical convex ā€œVā€ shape.
    Type: Application
    Filed: August 22, 2011
    Publication date: December 8, 2011
    Applicant: Taegu Tec, Ltd.
    Inventors: Chang Hee Choi, Chang Gyu Park, Hee-Seok Kim
  • Publication number: 20110255924
    Abstract: A cutting insert having a plurality of corner cutting edges has an upper face, a lower face, two longitudinal side faces and two transversal side faces connecting the upper face and the lower face. A through hole passes through central parts of the upper face and the lower face. The longitudinal side faces are opposite to each other and normal to both upper and lower faces, as are the transversal side faces. The upper face and the lower face are each provided with two chip discharge grooves, each chip discharge groove extending along a corresponding one of the transversal side faces, the two chip discharge grooves being inclined oppositely in the transverse direction so that the upper face and the lower face are each provided with two corner cutting edges at diagonally opposite corners. The longitudinal length of the insert is longer than the transversal length of the insert. The cutting insert can be mounted stably to a small-diametered cutter with a sufficient mounting surface.
    Type: Application
    Filed: October 13, 2010
    Publication date: October 20, 2011
    Applicant: TaeguTec, Ltd.
    Inventors: Chang Hee Choi, Chang Gyu PARK, Kang Sool JUNG
  • Patent number: 8021087
    Abstract: Tool holder assembly (TH) for multifunctional machining, such as drilling, boring, facing, and turning, eliminate interference between facing and turning, and secure an adequate chip groove space (10) for discharging chips therethrough without deterioration of a rigidity of the tool holder (TH), thereby securing a good quality of machining, and an exclusive adapter (TA) suitable to the foregoing tool holder (TH) assembly for multifunctional machining.
    Type: Grant
    Filed: March 11, 2004
    Date of Patent: September 20, 2011
    Assignee: Taegutec Ltd.
    Inventors: Chang Hee Choi, Hong Sick Park, Dae Wi Bae
  • Publication number: 20110164932
    Abstract: A milling cutter is provided with a cutting insert having improved main cutting edges. The main cutting edges are positioned along both lengthwise edges of a front surface, have a wave shape and are asymmetrical with each other. Main cutting edges positioned along both lengthwise edges of a back surface are rotationally symmetrical by 180 degrees from the main cutting edges of the front surface with respect to a longitudinal central axis of the cutting insert. In the milling cutter, the cutting inserts are alternately mounted in pockets formed on a side surface of the milling cutter so that the concavo-convex portions of the active main cutting edges of the cutting inserts which are adjacent to each other are staggered with respect to each other.
    Type: Application
    Filed: February 18, 2011
    Publication date: July 7, 2011
    Applicant: TaeguTec, Ltd.
    Inventors: Chang Hee Choi, Chang Gyu Park
  • Patent number: 7959383
    Abstract: The present invention provides a cutting insert and a cutting tool used with the same. A tool body includes at least one seating surface and a threaded hole extending as slanted with respect to the seating surface. At least one cutting insert having a mounting hole passing therethrough is removably secured on the seating surface. A screw passes through the mounting hole and is fastened to the threaded hole, thereby removably securing the cutting insert to the tool body. A wall surface of the mounting hole contacts a head of the screw about at least one first contact portion and at least one second contact portion. The first contact portion is formed at a level different from that of the second contact portion along a longitudinal axis of the mounting hole. Contact angles at the first contact portions and the second contact portions are different from each other.
    Type: Grant
    Filed: September 6, 2006
    Date of Patent: June 14, 2011
    Assignee: Taegutec Ltd.
    Inventors: Chang Hee Choi, Chang Gyu Park
  • Patent number: D700640
    Type: Grant
    Filed: January 14, 2013
    Date of Patent: March 4, 2014
    Assignee: TaeguTec Ltd.
    Inventors: Chang Hee Choi, Jung Hoon Park