US3914059A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mechanical pencil
Assignee: Individual
•
Filing: 1974-02-28
•
Granted: 1975-10-21
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Expires: 1994-02-28
Abstract
Abstract A mechanical pencil has a lead container movably incorporated therein. The lower terminal portion of the pencil proper contains a lead protecting tube through which the lead extends in light frictional contact. The lead container is provided at the lower end thereof with a chuck which functions for clutching and releasing the lead alternately during operation thereof. Within the lower terminal portion is also a movable cylinder to which the chuck becomes attached when the chuck in a loosened state is moved downwardly to the extreme lowermost, and the movable cylinder is drawn up with the chuck when they rise until they reach the extreme uppermost position where the chuck is withdrawn from the cylinder and is clutched to the lead. The movable cylinder has an inwardly projecting rim which as it rises abuts the lead protecting tube thereby raising the lead protecting tube to a position inside the pencil proper. Two coil springs varying in thickness and length are provided, the longer one functioning for propelling the lead and the shorter one functioning for withdrawing the lead.
Inventors
- 👤 Yoshihide Mitsuya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 00:44
CPC Classifications
B; B43; B43K; B43K21/00; B43K21/02; B43K21/16
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
466 words
An automatic lead pencil having a pencil body with a terminal tubular end portion at the forward end of said pencil body when said pencil is pointed downward and wherein said lead can be made to extend from and retract into said end portion comprising: lead containing means within said pencil body for containing lead used in said pencil; expandable chuck means connected to and below said lead containing means when said pencil is pointed downward for clutching lead coming from said lead containing means; actuating means extending above said pencil body when said terminal end is pointed downward and operatively connected to said lead containing means for forcing said lead containing means downward, thereby actuating said chuck means, causing said chuck means to expand and allow the lead to pass therethrough; lead protecting means surrounding and frictionally holding the lead as the lead passes through and out of the terminal end of said pencil, said lead protecting means movably mounted within said terminal end extendable therefrom and retractable thereinto with the extension and retraction of the lead into and out of said pencil body; two springs within said pencil body positioned for biasing said lead containing means upward when said pencil is pointed downward, one of said springs being of lesser biasing strength than the other and positioned for being actuated by said actuating means before said stronger spring of the two is actuated, whereby depressing said actuating means with sufficient force to depress and actuate only the weaker of said two springs will cause said chuck means to advance to a first position below said lead containing means while clutching said lead, then advance further, expand and release said lead, thereby moving said lead downward a predetermined length from said lead containing means into and through said lead protecting means and out of said pencil, and whereby releasing said actuating means will cause said spring to expand, drawing said lead containing means and said chuck means upward, thereby causing said chuck means to close and grasp said lead once again; slidable retracting means elevatably and freely fitted within said terminal end for holding said lead protecting means and for engaging with said chuck means when said chuck means is fully extended and expanded, whereby depressing said actuating means with sufficient force to first compress the weaker spring and then the stronger spring will cause said chuck means to fully extend to a second position and engage with said retracting means and whereby releasing said actuating means will cause said springs to expand, drawing said lead containing means, said chuck means attached to said lead containing means, and said retracting means engaged with said chuck means upward, thereby withdrawing said lead protecting means and said lead within said lead protecting means into said pencil body.
Claim 2
Dependent Claim
466 words
An automatic lead pencil having a pencil body with a terminal tubular end portion at the forward end of said pencil body when said pencil is pointed downward and wherein said lead can be made to extend from and retract into said end portion comprising: lead containing means within said pencil body for containing lead used in said pencil; expandable chuck means connected to and below said lead containing means when said pencil is pointed downward for clutching lead coming from said lead containing means; actuating means extending above said pencil body when said terminal end is pointed downward and operatively connected to said lead containing means for forcing said lead containing means downward, thereby actuating said chuck means, causing said chuck means to expand and allow the lead to pass therethrough; lead protecting means surrounding and frictionally holding the lead as the lead passes through and out of the terminal end of said pencil, said lead protecting means movably mounted within said terminal end extendable therefrom and retractable thereinto with the extension and retraction of the lead into and out of said pencil body; two springs within said pencil body positioned for biasing said lead containing means upward when said pencil is pointed downward, one of said springs being of lesser biasing strength than the other and positioned for being actuated by said actuating means before said stronger spring of the two is actuated, whereby depressing said actuating means with sufficient force to depress and actuate only the weaker of said two springs will cause said chuck means to advance to a first position below said lead containing means while clutching said lead, then advance further, expand and release said lead, thereby moving said lead downward a predetermined length from said lead containing means into and through said lead protecting means and out of said pencil, and whereby releasing said actuating means will cause said spring to expand, drawing said lead containing means and said chuck means upward, thereby causing said chuck means to close and grasp said lead once again; slidable retracting means elevatably and freely fitted within said terminal end for holding said lead protecting means and for engaging with said chuck means when said chuck means is fully extended and expanded, whereby depressing said actuating means with sufficient force to first compress the weaker spring and then the stronger spring will cause said chuck means to fully extend to a second position and engage with said retracting means and whereby releasing said actuating means will cause said springs to expand, drawing said lead containing means, said chuck means attached to said lead containing means, and said retracting means engaged with said chuck means upward, thereby withdrawing said lead protecting means and said lead within said lead protecting means into said pencil body.
Claim 3
Dependent Claim
180 words
An automatic pencil as claimed in claim 1 wherein said slidable retracting means is comprised of: a hollow cylinder slidably fitted within the terminal end of said pencil body having an outwardly expanded rim at the upper part thereof when the pencil is pointed downward for engaging with said chuck means and having an inwardly projecting rim at the bottom thereof when said pencil is pointed downward adapted to fit and retain therein said lead protecting means; and a rubber tube of larger diameter than said lead protecting means for fitting around and holding said lead protecting means within said hollow cylinder and hAving a hole therethrough for allowing said lead to pass therethrough to said lead protecting means from said lead containing means, said hole being of small enough diameter to frictionally hold said lead therein, whereby advancing said lead downward when said slidable retracting means is withdrawn inside the pencil body will cause said slidable retracting means to move downward within the pencil body due to the frictional attraction between the rubber tube and the lead passing therethrough.
Claim 4
Dependent Claim
32 words
A pencil as claimed in claim 1 wherein said two springs are positioned surrounding the upper portion of said chuck means where said chuck means is connected to said lead containing means.
Claim 5
Dependent Claim
37 words
A pencil as claimed in claim 3 wherein said two springs are positioned concentric with each other around the upper portion of said chuck means, and said weaker spring is of greater length than said stronger spring.
Claim 6
Dependent Claim
48 words
A pencil as claimed in claim 3 wherein separating means is positioned around the upper portion of said chuck means between said two springs for separating said springs, said weaker spring being on one side of said separating means and said stronger spring being on the other side.
References Cited (Backward Citations)
US3724960A
Cited
US3765781A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |