US 11,884,093 B2
Mechanical pencil
Takamasa Fukuda, Tokyo (JP); and Yusuke Koizumi, Tokyo (JP)
Assigned to MITSUBISHI PENCIL COMPANY, LIMITED, Tokyo (JP)
Appl. No. 17/603,426
Filed by MITSUBISHI PENCIL COMPANY, LIMITED, Tokyo (JP)
PCT Filed Feb. 20, 2020, PCT No. PCT/JP2020/006910
§ 371(c)(1), (2) Date Oct. 13, 2021,
PCT Pub. No. WO2020/217682, PCT Pub. Date Oct. 29, 2020.
Claims priority of application No. 2019-086686 (JP), filed on Apr. 26, 2019.
Prior Publication US 2022/0184995 A1, Jun. 16, 2022
Int. Cl. B43K 21/22 (2006.01); B43K 21/18 (2006.01)
CPC B43K 21/22 (2013.01) [B43K 21/18 (2013.01)] 13 Claims
OG exemplary drawing
 
1. 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.