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).
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Publication number: 20240051329Abstract: Provided is a writing implement that maximizes the effective area of a viewer portion allowing visual recognition in the writing direction and that facilitates writing at a high level, at the same time. This writing implement is a writing implement A, including for example, a pen tip 20 that feeds ink from a writing implement body 10 and has a viewer portion 33 allowing visual recognition in the writing direction. The pen tip 20 is comprised of, at least, a writing part 25 and a retainer 30 having the viewer portion 33, an ink feeder portion 26 for feeding the ink from the writing implement body 10 to the writing part 25. The minimum width X of the viewer portion 33 is 3.7 mm or greater and a length Y of the viewer portion 33 is 7.4 mm or greater. The ink feeder portion 26 is arranged on one side of the viewer portion 33.Type: ApplicationFiled: February 9, 2022Publication date: February 15, 2024Applicant: MITSUBISHI PENCIL COMPANY, LIMITEDInventors: Hirotake IZAWA, Toshimi KAMITANI, Chihiro MOCHIZUKI, Kaito TSUKADA
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Publication number: 20230406029Abstract: Provided is a fiber-bundled part for writing instruments having excellent strength and durability, as well as a pen tip and a writing instrument using the fiber-bundled part, which can be suitably used for pen tips, ink feed cores and relay cores of writing instruments such as marking pens and felt-tip pens. The fiber-bundled part for writing instruments of the present disclosure is used for the ink feed core leading to the pen tip or a writing pen core, and comprises a multifilament of long fibers having different melting points, and the multifilament at least contain crimped fibers.Type: ApplicationFiled: October 7, 2021Publication date: December 21, 2023Applicant: MITSUBISHI PENCIL COMPANY, LIMITEDInventors: Toshihiro TAKAHASHI, Toshimi KAMITANI, Hirotake IZAWA
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Publication number: 20220324250Abstract: Provided is a writing implement having a pen tip with a viewer part where the effective area for allowing visual recognition of the writing direction relative to the entire pen tip is maximized without impairing ink discharge. The pen tip feeds ink from the writing implement body, and the writing direction can be recognized through the viewer part. The pen tip has a holding body with the viewer part and a writing part that attaches a writing core having a U-shaped or L-shaped configuration to the holding body. The part of the writing core in contact with the side surface of the holding body is formed to have a square cross-section.Type: ApplicationFiled: August 3, 2020Publication date: October 13, 2022Applicant: MITSUBISHI PENCIL COMPANY, LIMITEDInventors: Hirotake IZAWA, Toshimi KAMITANI
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Patent number: 9669649Abstract: 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: GrantFiled: February 20, 2013Date of Patent: June 6, 2017Assignee: MITSUBISHI PENCIL COMPANY, LIMITEDInventors: Hirotake Izawa, Daisaku Morimoto
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Patent number: 9358828Abstract: 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: GrantFiled: February 20, 2013Date of Patent: June 7, 2016Assignee: MITSUBISHI PENCIL COMPANY, LIMITEDInventors: Hirotake Izawa, Kei Oomoto
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Patent number: 9302529Abstract: 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: GrantFiled: April 2, 2012Date of Patent: April 5, 2016Assignee: MITSUBISHI PENCIL CO., LTD.Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
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Publication number: 20150050061Abstract: 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: ApplicationFiled: February 20, 2013Publication date: February 19, 2015Applicant: MITSUBISHI PENCIL COMPANY, LIMITEDInventors: Hirotake Izawa, Daisaku Morimoto
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Publication number: 20150023714Abstract: 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: ApplicationFiled: February 20, 2013Publication date: January 22, 2015Applicant: MITSUBISHI PENCIL COMPANY, LIMITEDInventors: Hirotake Izawa, Kei Oomoto
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Publication number: 20140016982Abstract: 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: ApplicationFiled: April 2, 2012Publication date: January 16, 2014Applicant: MITSUBISHI PENCIL CO., LTD.Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
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Patent number: 8337107Abstract: 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: GrantFiled: December 18, 2008Date of Patent: December 25, 2012Assignee: Mitsubishi Pencil Co., Ltd.Inventors: Norio Ohsawa, Takeo Fukumoto, Yoshitoshi Osano, Takeshi Kobayashi, Hirotake Izawa, Kyo Nakayama
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Patent number: 8328446Abstract: 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: GrantFiled: September 15, 2010Date of Patent: December 11, 2012Assignee: Mitsubishi Pencil Co., Ltd.Inventors: Hirotake Izawa, Takeo Fukumoto, Norio Ohsawa, Kyo Nakayama, Yoshitoshi Osano
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Publication number: 20110002728Abstract: 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: ApplicationFiled: September 15, 2010Publication date: January 6, 2011Applicant: MITSUBISHI PENCIL CO., LTD.Inventors: Hirotake Izawa, Takeo Fukumoto, Noio Ohsawa, Kyo Nakayama, Yoshitoshi Osano
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Publication number: 20100322695Abstract: 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: ApplicationFiled: December 18, 2008Publication date: December 23, 2010Applicant: MITSUBISHI PENCIL CO., LTD.Inventors: Norio Ohsawa, Takeo Fukumoto, Yoshitoshi Osano, Takeshi Kobayashi, Hirotake Izawa, Kyo Nakayama
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Patent number: 7850381Abstract: 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: GrantFiled: December 18, 2008Date of Patent: December 14, 2010Assignee: Mitsubishi Pencil Co., Ltd.Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
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Patent number: 7850380Abstract: 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: GrantFiled: October 15, 2008Date of Patent: December 14, 2010Assignee: Mitsubishi Pencil Co., Ltd.Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
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Publication number: 20100266325Abstract: 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: ApplicationFiled: December 18, 2008Publication date: October 21, 2010Applicant: MITSUBISHI PENCIL CO., LTD.Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
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Patent number: 7815385Abstract: 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: GrantFiled: December 11, 2009Date of Patent: October 19, 2010Assignee: Mitsubishi Pencil Co., Ltd.Inventors: Hirotake Izawa, Takeo Fukumoto, Norio Ohsawa, Kyo Nakayama, Yoshitoshi Osano
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Publication number: 20100254746Abstract: 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: ApplicationFiled: October 15, 2008Publication date: October 7, 2010Applicant: MITSUBISHI PENCIL CO., LTD.Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
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Patent number: 7806615Abstract: 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: GrantFiled: October 15, 2008Date of Patent: October 5, 2010Assignee: Mitsubishi Pencil Co., Ltd.Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama
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Patent number: 7802936Abstract: 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: GrantFiled: October 15, 2008Date of Patent: September 28, 2010Assignee: Mitsubishi Pencil Co., Ltd.Inventors: Hirotake Izawa, Takeshi Kobayashi, Kyo Nakayama