Mitsubishi Pencil Company, Limited

Hirotake Izawa

Kyo Nakayama

Takeshi Kobayashi

Takeo Fukumoto

Norio Ohsawa

Yoshitoshi Osano

Toshimi Kamitani

Kei Oomoto

Daisaku Morimoto

Chihiro Mochizuki

Kaito Tsukada

Toshihiro Takahashi

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 tipthat feeds ink from a writing implement bodyand has a viewer portionallowing visual recognition in the writing direction. The pen tipis comprised of, at least, a writing partand a retainerhaving the viewer portion, an ink feeder portionfor feeding the ink from the writing implement bodyto the writing part. The minimum width X of the viewer portionis 3.7 mm or greater and a length Y of the viewer portionis 7.4 mm or greater. The ink feeder portionis arranged on one side of the viewer portion. Specifically, the ink feeder portionis preferably adapted to be positioned on a near side during writing (on such a side that the pen tipis located on an obtuse angle side of the ink feeder portion).

Writing implement

This application is related to 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.

Fiber-bundled part for writing instruments, and pen tip and writing instrument using the fiber-bundled part

Cam facesandare continuously formed in a circle on upper and lower faces which are perpendicular to an axial direction of a rotatable camwhich constitutes a rotational drive mechanism. Elastic membersare formed integrally with a holder memberfor rotatably supporting the rotatable camto extend in the axial direction, and the first fixed cam and second fixed camandhaving 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 facesandof the rotatable cam. The rotatable camis 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 camis transmitted to the writing lead.

Mechanical pencil

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 chuckwhich is moved back and forth in conjunction with knock operation of a knock barto release and grip the writing lead L, and a holder chuckwhich 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 valveis provided in which a writing lead feeding unit is opened in a situation where the grip of the lead fixing chuckon the writing lead is released by the knock operation, and the holder chuckis disposed proximate to a writing lead outlet.

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 facesandare respectively formed at one end face and the other end face of a rotorin an axial direction, and first and second fixed cam facesandarranged 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 groovesin the axial direction are formed at a sliderof a pipe endwhich projects forwardly from a body cylinder. Therefore, the user can see the grooves(provided for the slider) rotated by rotation of the rotor

A writing lead () is grasped and released by reciprocation of a chuck () provided in a body cylinder () so as to inch the writing lead forward and a rotational drive mechanism is provided for rotationally driving a rotor () 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 () for supporting a pipe end () is accommodated in a base (A) 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.

A chuck unit () for grasping a writing lead () and a rotor () arranged to be movable in a direction of rotation and an axial direction within a body cylinder () are provided. First and second cam faces () and () 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 () and () 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.

A chuck () for grasping a writing lead and a rotor () arranged to be movable in a direction of rotation and an axial direction within a body cylinder (). 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 () 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.

A chuck () for grasping a writing lead and a rotor () arranged to be movable together in a direction of rotation and an axial direction within a body cylinder (). A rotational drive mechanism for the writing lead is formed such that first and second cam faces () and () 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 () and () 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 () interposed between a stopper () and a torque canceller (). As a result, a sense of uncomforting, when writing, generated in conjunction with the cushion action can be reduced.

A chuck () for grasping a writing lead and a rotor () arranged to be movable in a direction of rotation and an axial direction within a body cylinder (). A rotational drive mechanism for the writing lead is formed such that first and second cam faces () and () 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 () and () are arranged on the body cylinder side to face the above-mentioned first and second cam faces respectively. A pipe end () 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.

A chuck () for grasping a writing lead and a rotor () arranged to be movable in a direction of rotation and an axial direction within a body cylinder (). A rotational drive mechanism for the writing lead is formed such that first and second cam faces () and () 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 () and () are arranged on the body cylinder side to face the above-mentioned first and second cam faces respectively. An indicator () 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.

Growing community of inventors

Yokohama, Japan

Hirotake Izawa