Patents by Inventor Youichi Nakazato

Youichi Nakazato 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: 5700101
    Abstract: This invention is to a writing tool such as mechanical pencil or a ballpoint pen in which a writing shaft having a head member is inserted in an outer sleeve in such a manner that the head member projects from the outer sleeve. A stair or step and a spiral groove are provided on the forward inner surface and the rearward inner surface of a tubular cap, respectively, with an inside diameter of the rear part of the spiral groove being larger. A bearing part is brought into contact with a lead tank provided inside a forward art of the tubular part so that the forward part of the outer sleeve is movable in the axial direction and is locked in the turning direction against a rearward inner surface of the outer sleeve. The rearward part of the tubular body is provided with a slit, holding pieces of a stick-shaped object holder slidably inserted in said slit. A stick-shaped object is held by the holding pieces, and the projection is provided on each holder engaged with the spiral groove of the tubular cap.
    Type: Grant
    Filed: February 17, 1994
    Date of Patent: December 23, 1997
    Assignee: Kotobuki & Co., Ltd.
    Inventors: Shuhei Kageyama, Toshihiko Kageyama, Youichi Nakazato, Yoshihide Mitsuya
  • Patent number: 5683191
    Abstract: This invention is to a writing tool such as mechanical pencil or a ballpoint pen in which a writing shaft having a head member is inserted in an outer sleeve in such a manner that the head member projects from the outer sleeve. A stair or step and a spiral groove are provided on the forward inner surface and the rearward inner surface of a tubular cap, respectively, with an inside diameter of the rear part of the spiral groove being larger. A bearing part is brought into contact with a lead tank provided inside a forward art of the tubular part so that the forward part of the outer sleeve is movable in the axial direction and is locked in the turning direction against a rearward inner surface of the outer sleeve. The rearward part of the tubular body is provided with a slit, holding pieces of a stick-shaped object holder slidably inserted in said slit. A stick-shaped object is held by the holding pieces, and the projection is provided on each holder engaged with the spiral groove of the tubular cap.
    Type: Grant
    Filed: June 23, 1994
    Date of Patent: November 4, 1997
    Assignee: Kotobuki & Co., Ltd.
    Inventors: Shuhei Kageyama, Toshihiko Kageyama, Youichi Nakazato, Yoshihide Mitsuya
  • Patent number: 5370471
    Abstract: This invention is to a writing tool such as mechanical pencil or a ballpoint pen in which a writing shaft having a head member is inserted in an outer sleeve in such a manner that the head member projects from the outer sleeve. A stair or step and a spiral groove are provided on the forward inner surface and the rearward inner surface of a tubular cap, respectively, with an inside diameter of the rear part of the spiral groove being larger. A bearing part is brought into contact with a lead tank provided inside a forward art of the tubular part so that the forward part of the outer sleeve is movable in the axial direction and is locked in the turning direction against a rearward inner surface of the outer sleeve. The rearward part of the tubular body is provided with a slit, holding pieces of a stick-shaped object holder slidably inserted in said slit. A stick-shaped object is held by the holding pieces, and the projection is provided on each holder engaged with the spiral groove of the tubular cap.
    Type: Grant
    Filed: April 29, 1992
    Date of Patent: December 6, 1994
    Assignee: Kotobuki & Co., Ltd.
    Inventors: Shubei Kageyama, Toshihiko Kageyama, Youichi Nakazato, Yoshihide Mitsuya
  • Patent number: 5236270
    Abstract: This invention is to a writing tool such as mechanical pencil or a ballpoint pen in which a writing shaft having a head member is inserted in an outer sleeve in such a manner that the head member projects from the outer sleeve. A stair or step and a spiral groove are provided on the forward inner surface and the rearward inner surface of a tubular cap, respectively, with an inside diameter of the rear part of the spiral groove being larger. A bearing part is brought into contact with a lead tank provided inside a forward art of the tubular part so that the forward part of the outer sleeve is movable in the axial direction and is locked in the turning direction against a rearward inner surface of the outer sleeve. The rearward part of the tubular body is provided with a slit, holding pieces of a stick-shaped object holder slidably inserted in said slit. A stick-shaped object is held by the holding pieces, and the projection is provided on each holder engaged with the spiral groove of the tubular cap.
    Type: Grant
    Filed: August 4, 1992
    Date of Patent: August 17, 1993
    Assignee: Kotobuki & Co. Ltd.
    Inventors: Shuhei Kageyama, Toshihiko Kageyama, Youichi Nakazato, Yoshihide Mitsuya
  • Patent number: 5207522
    Abstract: This invention is to a writing tool such as mechanical pencil or a ballpoint pen in which a writing shaft having a head member is inserted in an outer sleeve in such a manner that the head member projects from the outer sleeve. A stair or step and a spiral groove are provided on the forward inner surface and the rearward inner surface of a tubular cap, respectively, with an inside diameter of the rear part of the spiral groove being larger. A bearing part is brought into contact with a lead tank provided inside a forward art of the tubular part so that the forward part of the outer sleeve is movable in the axial direction and is locked in the turning direction against a rearward inner surface of the outer sleeve. The rearward part of the tubular body is provided with a slit, holding pieces of a stick-shaped object holder slidably inserted in said slit. A stick-shaped object is held by the holding pieces, and the projection is provided on each holder engaged with the spiral groove of the tubular cap.
    Type: Grant
    Filed: May 6, 1991
    Date of Patent: May 4, 1993
    Assignee: Kotobuki & Co., Ltd.
    Inventors: Shuhei Kageyama, Toshihiko Kageyama, Youichi Nakazato, Yoshihide Mitsuya
  • Patent number: 5090831
    Abstract: A writing instrument wherein a rear cap is rotatably connected through a connector to a rear end of an outer tube into which a core pipe is axially slidably inserted, a guide member for an eraser is axially slidably inserted into the rear cap for axial engagement, a spiral member is spirally connected to an eraser receiving member which supports an eraser axially slidably inserted into a spiral member for axial engagement, the spiral member having a front end axially slidably connected to the connector for axial engagement, and the eraser guide member is urged in a withdrawing direction by means of an elastic body so that the guide member is held at a fixed projected position during non-knocking.
    Type: Grant
    Filed: December 11, 1990
    Date of Patent: February 25, 1992
    Assignee: Kotobuki & Co., Ltd.
    Inventors: Hidehei Kageyama, Yoshihide Mitsuya, Youichi Nakazato
  • Patent number: 5074694
    Abstract: Mechanism for putting the head of a shaft into and out of the head of an outer sleeve comprised of an outer sleeve (1), a long hole (2) formed in the outer sleeve (1), and a clip (3) to be put into and out of the outer sleeve (1) through the long hole (2). A shaft (4) is inserted in the outer sleeve (1), and a cam mechanism (8) cooperates with the clip (3) in a manner that causes the cam mechanism (8) to move forward and backward in an axial direction according to in and out movement of the clip (3). A spring (6) spring-biases the shaft (4) toward the cam mechanism.
    Type: Grant
    Filed: October 31, 1990
    Date of Patent: December 24, 1991
    Assignee: Kotobuki & Co., Ltd.
    Inventors: Youichi Nakazato, Masuo Kubota, Shubei Kageyama, Yoshihide Mitsuya
  • Patent number: 5062727
    Abstract: This invention is to a writing tool such as mechanical pencil or a ballpoint pen in which a writing shaft having a head member is inserted in an outer sleeve in such a manner that the head member projects from the outer sleeve. A stair or step and a spiral groove are providd on the forward inner surface and the rearward inner surface of a tubular cap, respectively with an inside diameter of the rear part of the spiral groove being larger. A bearing part is brought into contact with a lead tank provided inside a forward art of the tubular part so that the forward part of the outer sleeve is movable in the axial direction and is locked in the turning direction against a rearward inner surface of the outer sleeve. The rearward part of the tubular body is provided with a slit, holding pieces of a stick-shaped object holder slidably inserted in said slit. A stick-shaped object is held by the holding pieces, and the projection is provided on each holder engaged with the spiral groove of the tubular cap.
    Type: Grant
    Filed: November 21, 1988
    Date of Patent: November 5, 1991
    Assignee: Kotobuki & Co., Ltd.
    Inventors: Shubei Kageyama, Toshihiko Kageyama, Youichi Nakazato, Yoshihide Mitsuya
  • Patent number: 5022774
    Abstract: This invention is to a writing tool such as mechanical pencil or a ballpoint pen in which a writing shaft having a head member is inserted in an outer sleeve in such a manner that the head member projects from the outer sleeve. A stair or step and a spiral groove are provided on the forward inner surface and the rearward inner surface of a tubular cap, respectively, with an inside diameter of the rear part of the spiral groove being larger. A bearing part is brought into contact with a lead tank provided inside a forward art of the tubular part so that the forward part of the outer sleeve is movable in the axial direction and is locked in the turning direction against a rearward inner surface of the outer sleeve. The rearward part of the tubular body is provided with a slit, holding pieces of a stick-shaped object holder slidably inserted in said slit. A stick-shaped object is held by the holding pieces, and the projection is provided on each holder engaged with the spiral groove of the tubular cap.
    Type: Grant
    Filed: October 7, 1988
    Date of Patent: June 11, 1991
    Assignee: Kotobuki & Co., Ltd.
    Inventors: Shuhei Kageyama, Toshihiko Kageyama, Youichi Nakazato, Yoshihide Mitsuya
  • Patent number: 5018891
    Abstract: A writing instrument wherein a rear cap is rotatably connected through a connector to a rear end of an outer tube into which a core pipe is axially slidably inserted, a guide member for an eraser is axially slidably inserted into the rear cap for axial engagement, a spiral member is spirally connected to an eraser receiving member which supports an eraser axially slidably inserted into a spiral member for axial engagement, the spiral member having a front end axially slidably connected to the connector for axial engagement, and the eraser guide member is urged in a withdrawing direction by means of an elastic body so that the guide member is held at a fixed projected position during non-knocking.
    Type: Grant
    Filed: July 10, 1989
    Date of Patent: May 28, 1991
    Assignee: Kotobuko & Co., Ltd.
    Inventors: Hidehei Kageyama, Yoshihide Mitsuya, Youichi Nakazato
  • Patent number: 4973179
    Abstract: Mechanism for putting the head of a shaft into and out of the head of an outer sleeve comprised of an outer sleeve (1), a long hole (2) formed in the outer sleeve (1), and a clip (3) to be put into and out of the outer sleeve (1) through the long hole (2). A shaft (4) is inserted in the outer sleeve (1), and a cam mechanism (8) cooperates with the clip (3) in a manner that causes the cam mechanism (8) to move forward and backward in an axial direction according to in and out movement of the clip (3). A spring (6) spring-biases the shaft (4) toward the cam mechanism.
    Type: Grant
    Filed: April 12, 1989
    Date of Patent: November 27, 1990
    Assignee: Kotobuki & Co., Ltd.
    Inventors: Youichi Nakazato, Masuo Kubota, Shuhei Kageyama, Yoshihide Mitsuya
  • Patent number: 4957384
    Abstract: A mechanical pencil in which a lead guide pipe may protect a lead in a range from a lead chuck to the tip member or an extremity end of the slider by the tip member or the slider or the projection bar as well as the lead guide pipe so as to protect the lead and to prevent a breakage of the lead and a clogging of broken lead.
    Type: Grant
    Filed: April 14, 1989
    Date of Patent: September 18, 1990
    Assignee: Kotobuki & Co., Ltd.
    Inventors: Hidehei Kageyama, Yoshihide Mitsuya, Youichi Nakazato
  • Patent number: 4955739
    Abstract: A mechanical pencil is disclosed in which lead can be advanced in one of two ways; either automatically upon release of writing pressure on the pencil, or selectively manually by pressing inwardly against a side push button. The pencil includes an outer cylinder with a side pushing hole formed therein, and a side push button movably disposed in the side pushing hole. The side push button contacts a lever which is totally mounted within the outer cylinder and which contacts a lead advanced mechanism. Upon pressing in of the side push button, the lever is pivoted about its axis and caused to press downwardly against the lead advance mechanism to thereby cause advancement of a lead. Advancement of lead is also performed upon release of writing pressure of the pencil by way of a slider mechanism which is biased outwardly by way of a resilient member and which is forced outwardly by the resilient member upon release of writing pressure.
    Type: Grant
    Filed: October 21, 1988
    Date of Patent: September 11, 1990
    Assignee: Kotobuki & Co., Ltd.
    Inventors: Hidehei Kageyama, Yoshihide Mitsuya, Youichi Nakazato