Mechanical pencil
AssigneeMitsubishi Pencil Company, Limited
InventorsTakamasa Fukuda, Yusuke Koizumi
Life of this patent
Estimating the term…
Abstract
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.
Claims13
A mechanical pencil which comprises
- a ball chuck allowing advance of the lead and preventing retraction,
- 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 drop difference provided at the ring-shaped cam face, 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 when the abutting part moves along the feed cam face according to rotation of the rotary part and the abutting part falls into the drop difference,
- wherein the mechanical pencil is configured so as to adjust the height of the drop difference to adjust the amount of feed of the lead, and
- wherein the mechanical pencil further comprises a ring-shaped or cylindrical first cam member and a ring-shaped or cylindrical second cam member arranged at the outside of the first cam member in the diametrical direction, the first cam member and the second cam member cooperating to configure the feed cam face.
A mechanical pencil which comprises
- a ball chuck allowing advance of the lead and preventing retraction,
- 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 and an axial direction drop difference provided at the ring-shaped cam face,
- 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,
- a ring-shaped or cylindrical first cam member, and
- a ring-shaped or cylindrical second cam member arranged outside from the first cam member in the diametrical direction,
- the first cam member and the second cam member cooperating to form the feed cam face, and
- 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 when the abutting part moves along the feed cam face according to rotation of the rotary part and the abutting part falls into the drop difference,
- wherein the first cam member is formed with a first slanted surface, the second cam member is formed with a second slanted surface, and the first slanted surface and the second slanted surface cooperate to configure the feed cam face.
Dependencies are inferred from the claim text.