Patents by Inventor Hirotake Izawa

Hirotake Izawa 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: 9669649
    Abstract: Cam faces 24a and 24b are continuously formed in a circle on upper and lower faces which are perpendicular to an axial direction of a rotatable cam 24 which constitutes a rotational drive mechanism 21. Elastic members 23b are formed integrally with a holder member 23 for rotatably supporting the rotatable cam 24 to extend in the axial direction, and the first fixed cam and second fixed cam 23c and 23d having a small number of cam faces at butts and tips of the elastic members are arranged to face each other via the upper and lower cam faces 24a and 24b of the rotatable cam 24. The rotatable cam 24 is retreated and moved forward in the axial direction by writing pressure applied to a writing lead to be rotationally driven in one direction and rotational motion of the rotatable cam 24 is transmitted to the writing lead.
    Type: Grant
    Filed: February 20, 2013
    Date of Patent: June 6, 2017
    Assignee: MITSUBISHI PENCIL COMPANY, LIMITED
    Inventors: Hirotake Izawa, Daisaku Morimoto
  • Patent number: 9358828
    Abstract: A mechanical pencil is provided which does not require operation of removing or re-fitting a cap but allows writing immediately after supplying a writing lead. A lead fixing chuck 4 which is moved back and forth in conjunction with knock operation of a knock bar 22 to release and grip the writing lead L, and a holder chuck 9 which is provided in front of the lead fixing chuck and holds the writing lead frictionally are arranged such that the writing lead can be gradually inched out by repeating the knock operation. An open/close mechanism having an open/close valve 27 is provided in which a writing lead feeding unit is opened in a situation where the grip of the lead fixing chuck 4 on the writing lead is released by the knock operation, and the holder chuck 9 is disposed proximate to a writing lead outlet.
    Type: Grant
    Filed: February 20, 2013
    Date of Patent: June 7, 2016
    Assignee: MITSUBISHI PENCIL COMPANY, LIMITED
    Inventors: Hirotake Izawa, Kei Oomoto
  • Patent number: 9302529
    Abstract: A mechanical pencil having a rotational drive mechanism which gradually rotates a writing lead on application of writing pressure and allowing rotational operation of the writing lead to be known reliably. First and second cam faces 6a and 6b are respectively formed at one end face and the other end face of a rotor 6 in an axial direction, and first and second fixed cam faces 13a and 14a arranged on the body cylinder side so as to respectively face the first and the second cam faces are provided to form the rotational drive mechanism for the writing lead. A plurality of grooves 8a in the axial direction are formed at a slider 8 of a pipe end 7 which projects forwardly from a body cylinder 1. Therefore, the user can see the grooves 8a (provided for the slider 8) rotated by rotation of the rotor 6.
    Type: Grant
    Filed: April 2, 2012
    Date of Patent: April 5, 2016
    Assignee: MITSUBISHI PENCIL CO., LTD.
    Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
  • Publication number: 20150050061
    Abstract: Cam faces 24a and 24b are continuously formed in a circle on upper and lower faces which are perpendicular to an axial direction of a rotatable cam 24 which constitutes a rotational drive mechanism 21. Elastic members 23b are formed integrally with a holder member 23 for rotatably supporting the rotatable cam 24 to extend in the axial direction, and the first fixed cam and second fixed cam 23c and 23d having a small number of cam faces at butts and tips of the elastic members are arranged to face each other via the upper and lower cam faces 24a and 24b of the rotatable cam 24. The rotatable cam 24 is retreated and moved forward in the axial direction by writing pressure applied to a writing lead to be rotationally driven in one direction and rotational motion of the rotatable cam 24 is transmitted to the writing lead.
    Type: Application
    Filed: February 20, 2013
    Publication date: February 19, 2015
    Applicant: MITSUBISHI PENCIL COMPANY, LIMITED
    Inventors: Hirotake Izawa, Daisaku Morimoto
  • Publication number: 20150023714
    Abstract: A mechanical pencil is provided which does not require operation of removing or re-fitting a cap but allows writing immediately after supplying a writing lead. A lead fixing chuck 4 which is moved back and forth in conjunction with knock operation of a knock bar 22 to release and grip the writing lead L, and a holder chuck 9 which is provided in front of the lead fixing chuck and holds the writing lead frictionally are arranged such that the writing lead can be gradually inched out by repeating the knock operation. An open/close mechanism having an open/close valve 27 is provided in which a writing lead feeding unit is opened in a situation where the grip of the lead fixing chuck 4 on the writing lead is released by the knock operation, and the holder chuck 9 is disposed proximate to a writing lead outlet.
    Type: Application
    Filed: February 20, 2013
    Publication date: January 22, 2015
    Applicant: MITSUBISHI PENCIL COMPANY, LIMITED
    Inventors: Hirotake Izawa, Kei Oomoto
  • Publication number: 20140016982
    Abstract: A mechanical pencil having a rotational drive mechanism which gradually rotates a writing lead on application of writing pressure and allowing rotational operation of the writing lead to be known reliably. First and second cam faces 6a and 6b are respectively formed at one end face and the other end face of a rotor 6 in an axial direction, and first and second fixed cam faces 13a and 14a arranged on the body cylinder side so as to respectively face the first and the second cam faces are provided to form the rotational drive mechanism for the writing lead. A plurality of grooves 8a in the axial direction are formed at a slider 8 of a pipe end 7 which projects forwardly from a body cylinder 1. Therefore, the user can see the grooves 8a (provided for the slider 8) rotated by rotation. of the rotor 6.
    Type: Application
    Filed: April 2, 2012
    Publication date: January 16, 2014
    Applicant: MITSUBISHI PENCIL CO., LTD.
    Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
  • Patent number: 8337107
    Abstract: A writing lead (10) is grasped and released by reciprocation of a chuck (3) provided in a body cylinder (1) so as to inch the writing lead forward and a rotational drive mechanism is provided for rotationally driving a rotor (5) in one direction in conjunction with retreat operation by the writing pressure applied to the writing lead and forward movement by releasing the writing pressure. A pipe support member (8) for supporting a pipe end (7) is accommodated in a base (1A) which constitutes a front end portion of the body cylinder, and a retreat drive mechanism is provided for gradually retreating the pipe support member into the body cylinder in conjunction with rotational drive operation of the rotor. With the above-mentioned structure, a pipe-slide type mechanical pencil can maintain an amount of projection of the writing lead from the pipe end within a certain range.
    Type: Grant
    Filed: December 18, 2008
    Date of Patent: December 25, 2012
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Norio Ohsawa, Takeo Fukumoto, Yoshitoshi Osano, Takeshi Kobayashi, Hirotake Izawa, Kyo Nakayama
  • Patent number: 8328446
    Abstract: A chuck unit (4) for grasping a writing lead (10) and a rotor (6) arranged to be movable in a direction of rotation and an axial direction within a body cylinder (1) are provided. First and second cam faces (6a) and (6b) are respectively formed at one end face and another end face of the rotor in the axial direction, and first and second fixed cam faces (13a) and (17a) are arranged on the body cylinder side to face the first and second cam faces respectively. The first cam face in the rotor is brought into abutment with and meshed with the first fixed cam face by retreat operation of the chuck unit under writing pressure, and the second cam face in the rotor is brought into abutment with and meshed with the second fixed cam face by releasing the writing pressure, so that the rotor rotates, whereby the writing lead also rotates.
    Type: Grant
    Filed: September 15, 2010
    Date of Patent: December 11, 2012
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Hirotake Izawa, Takeo Fukumoto, Norio Ohsawa, Kyo Nakayama, Yoshitoshi Osano
  • Publication number: 20110002728
    Abstract: A chuck unit (4) for grasping a writing lead (10) and a rotor (6) arranged to be movable in a direction of rotation and an axial direction within a body cylinder (1) are provided. First and second cam faces (6a) and (6b) are respectively formed at one end face and another end face of the rotor in the axial direction, and first and second fixed cam faces (13a) and (17a) are arranged on the body cylinder side to face the first and second cam faces respectively. The first cam face in the rotor is brought into abutment with and meshed with the first fixed cam face by retreat operation of the chuck unit under writing pressure, and the second cam face in the rotor is brought into abutment with and meshed with the second fixed cam face by releasing the writing pressure, so that the rotor rotates, whereby the writing lead also rotates.
    Type: Application
    Filed: September 15, 2010
    Publication date: January 6, 2011
    Applicant: MITSUBISHI PENCIL CO., LTD.
    Inventors: Hirotake Izawa, Takeo Fukumoto, Noio Ohsawa, Kyo Nakayama, Yoshitoshi Osano
  • Publication number: 20100322695
    Abstract: It is arranged that a writing lead (10) is grasped and released by reciprocation of a chuck (3) provided in a body cylinder (1) so as to inch the above-mentioned writing lead forward and a rotational drive mechanism is provided for rotationally driving a rotor (5) in one direction in conjunction with retreat operation by the writing pressure applied to the above-mentioned writing lead and forward movement by releasing the writing pressure. A pipe support member (8) for supporting a pipe end (7) is accommodated in a base (1A) which constitutes a front end portion of the above-mentioned body cylinder, and a retreat drive mechanism is provided for gradually retreating the pipe end supported by the above-mentioned pipe support member towards the above-mentioned body cylinder in conjunction with rotational drive operation of the above-mentioned rotor which constitutes the above-mentioned rotational drive mechanism.
    Type: Application
    Filed: December 18, 2008
    Publication date: December 23, 2010
    Applicant: MITSUBISHI PENCIL CO., LTD.
    Inventors: Norio Ohsawa, Takeo Fukumoto, Yoshitoshi Osano, Takeshi Kobayashi, Hirotake Izawa, Kyo Nakayama
  • Patent number: 7850381
    Abstract: A chuck (4) for grasping a writing lead and a rotor (6) arranged to be movable together in a direction of rotation and an axial direction within a body cylinder (1). A rotational drive mechanism for the writing lead is formed such that first and second cam faces (6a) and (6b) are respectively formed at one end face and another end face of the rotor in the axial direction, and first and second fixed cam faces (13a) and (14a) are arranged on the body cylinder side to face the above-mentioned first and second cam faces respectively. Retreat operation and forward movement (cushion action) of the writing lead by writing pressure are provided with a damping effect by sticky grease (19) interposed between a stopper (16) and a torque canceller (17). As a result, a sense of uncomforting, when writing, generated in conjunction with the cushion action can be reduced.
    Type: Grant
    Filed: December 18, 2008
    Date of Patent: December 14, 2010
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
  • Patent number: 7850380
    Abstract: A chuck (4) for grasping a writing lead and a rotor (6) arranged to be movable in a direction of rotation and an axial direction within a body cylinder (1). By axial movement of the rotor in conjunction with writing operation, the rotor rotates and the writing lead is also subjected to rotational movement. The writing lead can be inched out of the chuck by way of knock operation of the knock cover (26) arranged at a rear end port ion of the body cylinder. A separation part having a gap (G) is formed at any location along a knock operation transmitting path between the above-mentioned knock cover and the above-mentioned chuck, the separation part transmits the above-mentioned knock operation to the above-mentioned chuck and inhibits rotation operation from being transmitted.
    Type: Grant
    Filed: October 15, 2008
    Date of Patent: December 14, 2010
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
  • Publication number: 20100266325
    Abstract: A chuck (4) for grasping a writing lead and a rotor (6) arranged to be movable together in a direction of rotation and an axial direction within a body cylinder (1) are provided. A rotational drive mechanism for the writing lead is formed such that first and second cam faces (6a) and (6b) are respectively formed at one end face and another end face of the rotor in the axial direction, and first and second fixed cam faces (13a) and (14a) are arranged on the body cylinder side to face the above-mentioned first and second cam faces respectively. Retreat operation and forward movement (cushion action) of the writing lead by writing pressure are provided with a damping effect by sticky grease (19) interposed between a stopper (16) and a torque canceller (17). As a result, a sense of uncomforting, when writing, generated in conjunction with the cushion action can be reduced.
    Type: Application
    Filed: December 18, 2008
    Publication date: October 21, 2010
    Applicant: MITSUBISHI PENCIL CO., LTD.
    Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
  • Patent number: 7815385
    Abstract: A chuck unit (4) for grasping a writing lead (10) and a rotor (6) arranged to be movable in a direction of rotation and an axial direction within a body cylinder (1) are provided. First and second cam faces (6a) and (6b) are respectively formed at one end face and another end face of the rotor in the axial direction, and first and second fixed cam faces (13a) and (17a) are arranged on the body cylinder side to face the first and second cam faces respectively. The first cam face in the rotor is brought into abutment with and meshed with the first fixed cam face by retreat operation of the chuck unit under writing pressure, and the second cam face in the rotor is brought into abutment with and meshed with the second fixed cam face by releasing the writing pressure, so that the rotor rotates, whereby the writing lead also rotates.
    Type: Grant
    Filed: December 11, 2009
    Date of Patent: October 19, 2010
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Hirotake Izawa, Takeo Fukumoto, Norio Ohsawa, Kyo Nakayama, Yoshitoshi Osano
  • Publication number: 20100254746
    Abstract: A chuck (4) for grasping a writing lead and a rotor (6) arranged to be movable in a direction of rotation and an axial direction within a body cylinder (1) are provided. A rotational drive mechanism for the writing lead is formed such that first and second cam faces (6a) and (6b) are respectively formed at one end face and another end face of the rotor in the axial direction, and first and second fixed cam faces (13a) and (14a) are arranged on the body cylinder side to face the above-mentioned first and second cam faces respectively. An indicator (6c) of a wedge-shaped notch is formed at a part of the rotor. The indicator can be observed through the body cylinder made of a transparent material. By this structure, a mechanical pencil is provided in which operation of the writing lead that is gradually rotated by way of writing pressure can be known certainly.
    Type: Application
    Filed: October 15, 2008
    Publication date: October 7, 2010
    Applicant: MITSUBISHI PENCIL CO., LTD.
    Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
  • Patent number: 7806615
    Abstract: A chuck (4) for grasping a writing lead and a rotor (6) arranged to be movable in a direction of rotation and an axial direction within a body cylinder (1). A rotational drive mechanism for the writing lead is formed such that first and second cam faces (6a) and (6b) are respectively formed at one end face and another end face of the rotor in the axial direction, and first and second fixed cam faces (13a) and (14a) are arranged on the body cylinder side to face the above-mentioned first and second cam faces respectively. A pipe end (7) for guiding the writing lead to interlock with retreat and forward movement of the writing lead while the writing proceeds is arranged to move in the same direction, in conjunction with retreat and forward movement of the above-mentioned chuck.
    Type: Grant
    Filed: October 15, 2008
    Date of Patent: October 5, 2010
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
  • Patent number: 7802936
    Abstract: A chuck (4) for grasping a writing lead and a rotor (6) arranged to be movable in a direction of rotation and an axial direction within a body cylinder (1). A rotational drive mechanism for the writing lead is formed such that first and second cam faces (6a) and (6b) are respectively formed at one end face and another end face of the rotor in the axial direction, and first and second fixed cam faces (13a) and (14a) are arranged on the body cylinder side to face the above-mentioned first and second cam faces respectively. An indicator (6c) of a wedge-shaped notch is formed at a part of the rotor. The indicator can be observed through the body cylinder made of a transparent material. By this structure, a mechanical pencil is provided in which operation of the writing lead that is gradually rotated by way of writing pressure can be known certainly.
    Type: Grant
    Filed: October 15, 2008
    Date of Patent: September 28, 2010
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
  • Publication number: 20100239351
    Abstract: A chuck (4) for grasping a writing lead and a rotor (6) arranged to be movable in a direction of rotation and an axial direction within a body cylinder (1) are provided. By axial movement of the rotor in conjunction with writing operation, the rotor rotates and the writing lead is also subjected to rotational movement. The writing lead can be inched out of the chuck by way of knock operation of the knock cover (26) arranged at a rear end port ion of the body cylinder. A separation part having a gap (G) is formed at any location along a knock operation transmitting path between the above-mentioned knock cover and the above-mentioned chuck, the separation part transmits the above-mentioned knock operation to the above-mentioned chuck and inhibits rotation operation from being transmitted. According to the above-mentioned structure, as the rotor and the knock cover are separated in a direction of rotation, it is possible to solve the problem of placing an obstacle to a rotational drive mechanism.
    Type: Application
    Filed: October 15, 2008
    Publication date: September 23, 2010
    Applicant: MITSUBISHI PENCIL CO., LTD.
    Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
  • Publication number: 20100232863
    Abstract: A chuck (4) for grasping a writing lead and a rotor (6) arranged to be movable in a direction of rotation and an axial direction within a body cylinder (1) are provided. A rotational drive mechanism for the writing lead is formed such that first and second cam faces (6a) and (6b) are respectively formed at one end face and another end face of the rotor in the axial direction, and first and second fixed cam faces (13a) and (14a) are arranged on the body cylinder side to face the above-mentioned first and second cam faces respectively. A pipe end (7) for guiding the writing lead to interlock with retreat and forward movement of the writing lead while the writing proceeds is arranged to move in the same direction, in conjunction with retreat and forward movement of the above-mentioned chuck.
    Type: Application
    Filed: October 15, 2008
    Publication date: September 16, 2010
    Applicant: MITSUBISHI PENCIL CO., LTD.
    Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
  • Publication number: 20100166486
    Abstract: A chuck unit (4) for grasping a writing lead (10) and a rotor (6) arranged to be movable in a direction of rotation and an axial direction within a body cylinder (1) are provided. First and second cam faces (6a) and (6b) are respectively formed at one end face and another end face of the rotor in the axial direction, and first and second fixed cam faces (13a) and (17a) are arranged on the body cylinder side to face the first and second cam faces respectively. The first cam face in the rotor is brought into abutment with and meshed with the first fixed cam face by retreat operation of the chuck unit under writing pressure, and the second cam face in the rotor is brought into abutment with and meshed with the second fixed cam face by releasing the writing pressure, so that the rotor rotates, whereby the writing lead also rotates.
    Type: Application
    Filed: December 11, 2009
    Publication date: July 1, 2010
    Applicant: MITSUBISHI PENCIL CO.,LTD.
    Inventors: Hirotake Izawa, Takeo Fukumoto, Noio Ohsawa, Kyo Nakayama, Yoshitoshi Osano