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US 6,805,511 B2Granted
Ball point pen
AssigneeThe Pilot Ink Co., Ltd.
InventorMasashi Ando
Life of this patent
Estimating the term…
Abstract
Ink and an ink follower are reserved in an ink tube. An elastic member urges a ball forward. When an outflow of ink is measured at intervals of a writing distance of 100 m, the value of outflow of ink per writing distance of 100 m until a measurement time just before outflow of 80% of the amount of charged ink from the start of writing is selected to be in a range between a value smaller by 20 mg than the outflow of ink in the writing distance range of from 0 m to 100 m and a value larger by 20 mg than the outflow of ink in the writing distance range of from 0 m to 100 m.
Claims7
A ball point pen comprising:
- a tip body including a front end edge portion, a ball seat provided inward at a front end, and a ball rotatably held in said front end edge portion and said ball seat;
- an ink tube formed to provide said tip body at a front end thereof;
- ink reserved in said ink tube;
- an ink follower disposed at a rear end of said ink and advancing with consumption of said ink, and
- an elastic member urging said ball forward to bring said ball into contact with an inner surface of said front end edge portion of said tip body,
- wherein the value of outflow of ink per writing distance of 100 m, until a measurement time just before outflow of 80% of the amount of charged ink from the start of writing in the case where an outflow of ink is measured at intervals of a writing distance of 100 m, is in a range between a value smaller by 20 mg than the outflow of ink in the writing distance range of from 0 m to 100 m and a value larger by 20 mg than the outflow of ink in the writing distance range of from 0 m to 100 m.
3 more elements
Dependencies are inferred from the claim text.