A mechanical pencil includes a ball chuck, a rotation drive mechanism having a rotary part and receiving an axial direction retraction operation due to writing pressure received by the lead held by the ball chuck and an axial direction advance operation due to release of the writing pressure to drive the rotary part to rotate in one direction, a feed cam face having a ring-shaped cam face vertical to the axial direction and an axial direction step part, and a slider having an abutting part abutting against the feed cam face and a holding chuck holding a lead and rotating upon receiving a rotation drive force of the rotary part, which is configured so that the lead held by the holding chuck is pulled out from the ball chuck due to the advance operation of the slider.

A mechanical pencil includes a ball chuck, a rotation drive mechanism having a rotary part and receiving an axial direction retraction operation due to writing pressure received by the lead held by the ball chuck and an axial direction advance operation due to release of the writing pressure to drive the rotary part to rotate in one direction, a feed cam face having a ring-shaped cam face vertical to the axial direction and an axial direction step part, and a slider having an abutting part abutting against the feed cam face and a holding chuck holding a lead and rotating upon receiving a rotation drive force of the rotary part, which is configured so that the lead held by the holding chuck is pulled out from the ball chuck due to the advance operation of the slider.

A mechanical pencil 1 includes a rotary member having a ball chuck 11, a rotation drive mechanism 30 having a rotary part 40 and driving the rotary part to rotate in one direction upon receiving a retracting motion in the axial direction due to writing pressure received by the lead clutched by the ball chuck and an advancing motion in the axial direction due to release of the writing pressure, and a cylindrical member 8 made of metal provided at one of the cylindrical barrel and the rotary member, the rotary member configured so as to rotate upon receiving rotational drive force of the rotary part whereby the lead clutched by the ball chuck rotates, the other of the cylindrical barrel and the rotary member slidingly contacting the surface of the cylindrical member whereby rotation of the rotary member due to the rotation drive mechanism is supported.

A mechanical pencil 1 includes a rotary member having a ball chuck 11, a rotation drive mechanism 30 having a rotary part 40 and driving the rotary part to rotate in one direction upon receiving a retracting motion in the axial direction due to writing pressure received by the lead clutched by the ball chuck and an advancing motion in the axial direction due to release of the writing pressure, and a cylindrical member 8 made of metal provided at one of the cylindrical barrel and the rotary member, the rotary member configured so as to rotate upon receiving rotational drive force of the rotary part whereby the lead clutched by the ball chuck rotates, the other of the cylindrical barrel and the rotary member slidingly contacting the surface of the cylindrical member whereby rotation of the rotary member due to the rotation drive mechanism is supported.

A multi-function writing instrument comprises a body extending in an axial direction, at least two writing elements arranged inside the body, each writing element comprising a writing head able to take up a retracted position in which the writing head is stowed in the body and a writing position in which the writing head protrudes from the body, one of the writing elements being a lead-holder system comprising a lead-holder mechanism and a lead container, the lead container comprising a side opening for inserting leads.

A multi-function writing instrument comprises a body extending in an axial direction, at least two writing elements arranged inside the body, each writing element comprising a writing head able to take up a retracted position in which the writing head is stowed in the body and a writing position in which the writing head protrudes from the body, one of the writing elements being a lead-holder system comprising a lead-holder mechanism and a lead container, the lead container comprising a side opening for inserting leads.

A mechanical pencil includes a writing lead, a chuck unit for chucking the writing lead, and a cushion spring configured to elastically support the chuck unit in such a manner that the chuck unit is retractable with a writing pressure. An output of the cushion spring, in response to a cushion stroke, is non-linear, and a slope of a spring constant, in a region where the cushion stroke is relatively small, is smaller than a slope of a spring constant in a region where the cushion stroke is relatively large.

A mechanical pencil includes a writing lead, a chuck unit for chucking the writing lead, and a cushion spring configured to elastically support the chuck unit in such a manner that the chuck unit is retractable with a writing pressure. An output of the cushion spring, in response to a cushion stroke, is non-linear, and a slope of a spring constant, in a region where the cushion stroke is relatively small, is smaller than a slope of a spring constant in a region where the cushion stroke is relatively large.

A mechanical pencil includes a writing lead, a chuck that chucks the writing lead and feeds the writing lead forward, and a shaft tube for housing the writing lead and the chuck. When a click operation for feeding the chuck forward is performed, a jet stream flowing forward is generated inside the shaft tube.

A mechanical pencil includes a writing lead, a chuck that chucks the writing lead and feeds the writing lead forward, and a shaft tube for housing the writing lead and the chuck. When a click operation for feeding the chuck forward is performed, a jet stream flowing forward is generated inside the shaft tube.