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US3883253A Expired / Lapsed US ⏱️ 0.0 years remaining

Mechanical pencil

Assignee: Pentel Co Ltd
•
Filing: 1973-02-22
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Granted: 1975-05-13
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Expires: 1993-02-22
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Abstract

Abstract There is provided a push type mechanical pencil with which a user can push out a lead with a fingertip work while keeping a writing posture and a grasping position unchanged. In this mechanical pencil, a hole is formed at the part of the outer cylinder at which a user''s finger tip will be positioned when the pencil is grasped in writing position, and there are also provided a push member slidably fitted in said hole with the lower end thereof extending into the inside of said outer cylinder, and an engaging member secured to the inner cylinder in contact with or in close proximity to the lower end of said push member whereby when the user pushes said push member downwardly toward the inner cylinder, the lower end of said push member pushes the engaging member to move forwardly against the spring force to thereby force out the lead.

Inventors

  • 👤 Takeo Naruse
  • 👤 Junichi Hashimoto
  • 👤 Hideaki Oikawa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-10 01:12
CPC Classifications
B; B43; B43K; B43K24/00; B43K24/02; B43K24/08; B43K24/082; B43K21/00; B43K21/02; B43K21/16; B43K21/20

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 274 words
In a push type mechanical pencil comprising an outer casing; an inner casing having at its fore end a lead gripping chuck means and also formed with a lead passage communicated with said chuck means and a spare leads housing tube communicated with said lead passage; and a spring means adapted to press said inner casing rearwardly along its axis, wherein said push type mechanical pencil further comprises a fore larger hole and a rear smaller hole both formed in alignment through said outer casing and defined by a bridge formed integral with said outer casing, said fore larger hole being formed at a place where a user''s fingertip is positioned when the user grasps said outer casing, an elastic push plate adapted to normally lie covering said holes along the external surface of said outer casing, said push plate being bent in L-shape at its rear end portion and tailed in said rear smaller hole such that said push plate is bendable about said bridge, said push plate having side walls suspending from both sides of its fore end portion and extending into the inside of said outer casing, and an engaging member secured to said inner casing at the rear part of said spring and having a tapered surface formed at the rear portion thereof on which the fore edges of said side walls of said push member acts, whereby when the user pushes said push plate downwardly toward the inner casing, the fore edges of said push plate push said engaging member to move forwardly against the resisting force of said spring, thereby pushing out the lead into a writing position.
Claim 2
Dependent Claim 274 words
In a push type mechanical pencil comprising an outer casing; an inner casing having at its fore end a lead gripping chuck means and also formed with a lead passage communicated with said chuck means and a spare leads housing tube communicated with said lead passage; and a spring means adapted to press said inner casing rearwardly along its axis, wherein said push type mechanical pencil further comprises a fore larger hole and a rear smaller hole both formed in alignment through said outer casing and defined by a bridge formed integral with said outer casing, said fore larger hole being formed at a place where a user''s fingertip is positioned when the user grasps said outer casing, an elastic push plate adapted to normally lie covering said holes along the external surface of said outer casing, said push plate being bent in L-shape at its rear end portion and tailed in said rear smaller hole such that said push plate is bendable about said bridge, said push plate having side walls suspending from both sides of its fore end portion and extending into the inside of said outer casing, and an engaging member secured to said inner casing at the rear part of said spring and having a tapered surface formed at the rear portion thereof on which the fore edges of said side walls of said push member acts, whereby when the user pushes said push plate downwardly toward the inner casing, the fore edges of said push plate push said engaging member to move forwardly against the resisting force of said spring, thereby pushing out the lead into a writing position.
Claim 3
Dependent Claim 39 words
A push type mechanical pencil as claimed in claim 1 wherein said push plate has pawls projecting horizontally from the bottom ends of said side walls thereof, said pawls being engageable with shoulders formed inside of said outer casing.
Claim 4
Dependent Claim 239 words
In a push type mechanical pencil comprising an outer casing; an inner casing having at its fore end a lead gripping chuck means and also formed with a lead passage communicated with said lead passage; and a spring means adapted to press said inner casing rearwardly along its axis, wherein said push type mechanical pencil further comprises an elongated slot formed at a part of said outer casing at which a user''s fingertip is positioned when the user grasps said outer casing in writing position, a push member formed of an elastic plate adapted to normally lie covering said slot along the external surface of said outer casing, said push member having side walls suspending from both sides of its fore end portion and extending into the inside of said outer casing, and an engaging member secured to said inner casing at the rear part of said spring and having a tapered surface formed at the rear portion thereof on which the fore edges of said side walls of said push member acts, whereby when the user pushes said push member downwardly toward the inner casing, the fore edges of said push member push the engaging member to move forwardly against the resisting force of said spring, thereby pushing out the lead into a writing position, wherein the rear end of said push member is held up by a stopper means provided in the inside of the outer casing.
Claim 5
Dependent Claim 239 words
In a push type mechanical pencil comprising an outer casing; an inner casing having at its fore end a lead gripping chuck means and also formed with a lead passage communicated with said lead passage; and a spring means adapted to press said inner casing rearwardly along its axis, wherein said push type mechanical pencil further comprises an elongated slot formed at a part of said outer casing at which a user''s fingertip is positioned when the user grasps said outer casing in writing position, a push member formed of an elastic plate adapted to normally lie covering said slot along the external surface of said outer casing, said push member having side walls suspending from both sides of its fore end portion and extending into the inside of said outer casing, and an engaging member secured to said inner casing at the rear part of said spring and having a tapered surface formed at the rear portion thereof on which the fore edges of said side walls of said push member acts, whereby when the user pushes said push member downwardly toward the inner casing, the fore edges of said push member push the engaging member to move forwardly against the resisting force of said spring, thereby pushing out the lead into a writing position, wherein the rear end of said push member is held up by a stopper means provided in the inside of the outer casing.

References Cited (Backward Citations)

US1490124A Cited
US1866072A Cited
US2340665A Cited
US2385442A Cited
US2523568A Cited
US3112734A Cited
US3558233A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-05-12 1978-11-11 1979-05-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-05-12 1982-11-11 1983-05-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-05-12 1986-11-11 1987-05-13 $7700.00 Window Closed / Lapsed

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