US4149813A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mechanical pencil with automatic and manual lead advance
Assignee: Faber Castell AG
•
Filing: 1977-03-16
•
Granted: 1979-04-17
•
Expires: 1997-03-16
Abstract
Abstract A mechanical pencil has an axially elongated hollow pencil body in which is slidable a tubular seat member. A lead-protecting sleeve is axially displaceable in the pencil body between a front position and a rear position and is urged into the front position with a relatively strong spring force. At least two jaws are axially displaceable on the seat and are moved radially closer as they move backwardly from the tip so as to grip a lead that projects backwardly from the lead-projecting sleeve. A relatively weak spring urges these jaws backwardly in the seat. An O-ring is provided in the lead-projecting sleeve so that each time the pencil tip is lifted from the writing surface the lead is automatically pulled forwardly by the strong spring force through the jaws. Similarly forward displacement of the seat in which the jaws rest allows for manual advance of a lead gripped by the jaws and passing through the lead-protecting sleeve.
Inventors
- 👤 Otto Katz
- 👤 Gunter Edel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:00
CPC Classifications
B; B43; B43K; B43K21/00; B43K21/02; B43K21/027; B43K21/04; B43K21/045; B43K21/16; B43K21/20
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
249 words
A mechanical pencil, comprising a longitudinally elongated at least partially hollow pencil body having a forward tip and provided internally with a seat having a seat surface spaced longitudinally backwardly from said tip; a lead-protecting sleeve longitudinally displaceable in said body between a front position relatively far from said seat and a back position relatively close to said seat, said sleeve having a longitudinally throughgoing passage dimensioned to receive a pencil lead; means for urging said sleeve forwardly into said front position with a relatively strong force; means in said sleeve frictionally engaging a lead therein for joint longitudinal displacement of said sleeve and a lead therein; at least two longitudinally displaceable jaws having outer surfaces at said seat and inner lead-gripping faces transversely and frictionally engageable with a lead projecting from said sleeve, at least one of said surfaces being so inclined that the two surfaces together converge in the backward direction toward said seat, whereby the transverse clamping force exerted by said jaws on a lead gripped between said faces increases as said jaws are moved backwardly towards said seat and decreases as said jaws are moved forwardly from said seat; and means urging said jaws backwardly in said seat with a relatively weak force, whereby when a lead is frictionally engaged in said sleeve and between said faces and said sleeve is in said back position said strong force can overcome said weak force and forwardly displace said sleeve, the lead engaged therein, and said jaws.
Claim 2
Dependent Claim
249 words
A mechanical pencil, comprising a longitudinally elongated at least partially hollow pencil body having a forward tip and provided internally with a seat having a seat surface spaced longitudinally backwardly from said tip; a lead-protecting sleeve longitudinally displaceable in said body between a front position relatively far from said seat and a back position relatively close to said seat, said sleeve having a longitudinally throughgoing passage dimensioned to receive a pencil lead; means for urging said sleeve forwardly into said front position with a relatively strong force; means in said sleeve frictionally engaging a lead therein for joint longitudinal displacement of said sleeve and a lead therein; at least two longitudinally displaceable jaws having outer surfaces at said seat and inner lead-gripping faces transversely and frictionally engageable with a lead projecting from said sleeve, at least one of said surfaces being so inclined that the two surfaces together converge in the backward direction toward said seat, whereby the transverse clamping force exerted by said jaws on a lead gripped between said faces increases as said jaws are moved backwardly towards said seat and decreases as said jaws are moved forwardly from said seat; and means urging said jaws backwardly in said seat with a relatively weak force, whereby when a lead is frictionally engaged in said sleeve and between said faces and said sleeve is in said back position said strong force can overcome said weak force and forwardly displace said sleeve, the lead engaged therein, and said jaws.
Claim 3
Dependent Claim
64 words
The pencil defined in claim 1, further comprising means for displacing said jaws independently of said sleeve longitudinally between a rearward position relatively close to said seat and a forward position relatively far from said seat, so that displacement of said jaws towards said forward position urges said lead gripped between said faces through said sleeve when said sleeve is in said front position.
Claim 4
Dependent Claim
41 words
The pencil defined in claim 2, wherein said displacing means comprise a hollow jacket having an outer circumferential surface movably engaged the inside surface of said body and an inside surface bounding a passage operative for movably receiving therein said jaws.
Claim 5
Dependent Claim
27 words
The pencil defined in claim 3, wherein said inner surface of said jacket has a conical cross-section converging in direction away from said tip of the body.
Claim 6
Dependent Claim
44 words
The pencil defined in claim 1, wherein said means with said strong force is a relatively strong spring braced between said body and said sleeve and said means with said weak force is a relatively weak spring braced between said jaws and said body.
Claim 7
Dependent Claim
59 words
The pencil defined in claim 1, wherein each of said jaws is formed at its respective inner face with a longitudinally extending lead-receiving inner recess and on its respective outer surface with an outwardly and transversely open outer recess, said pencil further comprising a rolling element in each of said outer recesses rollingly engaging said surface of said seat.
Claim 8
Dependent Claim
12 words
The pencil defined in claim 6, wherein said rolling elements are balls.
Claim 9
Dependent Claim
31 words
The pencil defined in claim 6, wherein when a lead is gripped in said inner recesses, said inner faces are spaced transversely apart and are out of contact with each other.
Claim 10
Dependent Claim
58 words
The pencil defined in claim 5, wherein said housing includes a tube longitudinally connected to said jacket and longitudinally displaceable between a rearward position relatively far from said tip and a forward position relatively close to said tip, said pencil further comprising a spring braced between said body and said tube and urging same into said rearward position.
Claim 11
Dependent Claim
25 words
The pencil defined in claim 9, wherein said jaws together form a tubular forwardly projecting extension receiving said sleeve and surrounded by said weak spring.
Claim 12
Dependent Claim
29 words
The pencil defined in claim 9, wherein said sleeve is formed with a backwardly pointed end engageable between said jaws to force said jaws apart on longitudinal engagement therewith.
Claim 13
Dependent Claim
21 words
The pencil defined in claim 11, wherein said jaws form a region of the same taper as said backward pointed end.
Claim 14
Dependent Claim
30 words
The pencil defined in claim 9, wherein said means in said sleeve frictionally engaging a lead therein is an elastomeric ring in said sleeve surrounding said passage adjacent said jacket.
Claim 15
Dependent Claim
25 words
The pencil defined in claim 13, wherein said sleeve includes a rear end portion formed with a rearwardly pointed end and carrying said elastomeric ring.
Claim 16
Dependent Claim
20 words
The pencil defined in claim 14, wherein said sleeve includes a tube and said rear end portion is press-fitted therein.
Claim 17
Dependent Claim
15 words
The pencil defined in claim 9, wherein said sleeve projects longitudinally forwardly from said tip.
Claim 18
Dependent Claim
16 words
The pencil defined in claim 9, wherein said strong spring is stiffer than said weak spring.
Claim 19
Dependent Claim
61 words
The pencil defined in claim 17, wherein said means in said sleeve frictionally engaging a lead therein engages such lead with a force sufficient to couple said sleeve and such lead for joint longitudinal displacement and compression of said weak spring, whereby said weak force is insufficient to longitudinally displace a lead in said sleeve relative to said means frictionally engaging.
Claim 20
Dependent Claim
36 words
The pencil defined in claim 9, wherein said jaws form at said inner faces a backwardly open and flaring recess, said tube carrying a forwardly pointed formation engageable in said recess to spread said jaws apart.
Claim 21
Dependent Claim
25 words
The pencil defined in claim 9; further comprising respective forward and rearward abutments in said body engaging said tube in said forward and rearward positions.
Claim 22
Dependent Claim
24 words
The pencil defined in claim 20; further comprising a removable cap covering the rear end of said tube and forming therein a lead-storage compartment.
Claim 23
Dependent Claim
35 words
The pencil defined in claim 20, wherein said tube is provided with a front end piece formed with a throughgoing aperture longitudinally aligned with said passage and having a front end engageable with said jaws.
Claim 24
Dependent Claim
34 words
The pencil defined in claim 22; further comprising an annular seat member longitudinally displaceable in said body and forming said seat, and means frictionally longitudinally linking said front end piece and said seat member.
Claim 25
Dependent Claim
24 words
The pencil defined in claim 23, wherein said means longitudinally linking is a deformable ring between said seat member and said front end piece.
Claim 26
Dependent Claim
28 words
The pencil defined in claim 23, wherein said front end piece is formed with a rear face in turn formed at said hole with a backwardly flaring recess.
Claim 27
Dependent Claim
27 words
The pencil defined in claim 20, wherein said tube is provided with an outwardly projecting rim, said spring between said body and said tube engaging said rim.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-16 | 1982-10-16 | 1983-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-16 | 1986-10-16 | 1987-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-16 | 1990-10-16 | 1991-04-17 | $7700.00 | Window Closed / Lapsed |