US3813175A - Mechanical pencil - Google Patents

Mechanical pencil Download PDF

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Publication number
US3813175A
US3813175A US00312117A US31211772A US3813175A US 3813175 A US3813175 A US 3813175A US 00312117 A US00312117 A US 00312117A US 31211772 A US31211772 A US 31211772A US 3813175 A US3813175 A US 3813175A
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US
United States
Prior art keywords
lead
tubular
mechanical pencil
guide bushing
slide member
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00312117A
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English (en)
Inventor
O Katz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Faber Castell AG
Original Assignee
AW Faber Castell GmbH and Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by AW Faber Castell GmbH and Co filed Critical AW Faber Castell GmbH and Co
Application granted granted Critical
Publication of US3813175A publication Critical patent/US3813175A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B43—WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
    • B43K—IMPLEMENTS FOR WRITING OR DRAWING
    • B43K21/00—Propelling pencils
    • B43K21/02—Writing-core feeding mechanisms
    • B43K21/22—Writing-cores gripping means, e.g. chucks

Definitions

  • the present invention relates to mechanical pencils, especially for thin leads, in which the lead is supported in a smaller diameter lead support tube carried by a slide member axially movable in a front portion of a tubular housing and in which the lead may be advanced in axial direction by axial pressure on an actuating member projecting from the rear and of the housing and actuating a collet or clamping mechanism adapted to engage a rear portion of the lead.
  • a mechanical pencil is already known in which the pencil, during use, abuts not only with the free end of the lead against the writing or drawing surface, but also with a rounded side face provided with a thickened portion in such a manner, that by pressure on the aforementioned surface, a tube for guiding the lead. is pushed into the housing of the pencil so that the lead will project further from the tube. In this way an advance of the lead is possible without interrupting the writing or drawing.
  • the enlargement at the free end of the lead support tube is provided in order to assure that the lead assumes at all time its correct position, that is that the lead will not project beyond the supporting tube to an extend which may cause breakage of the lead during use, but that the lead will sufficiently project beyond the support tube to permit proper writing or drawing.
  • the enlargement at the tip of the support tube has, however the disadvantage, that when the pencil is used in combination with a straight edge for drawing purposes, the enlarged tip will prevent a perfect guiding of this tip on the straight edge, especially if the pencil is held at differently inclined positions.
  • the mechanical pencil according to the present invention mainly comprises an elongated tubular housing, a guide bushing in the housing, a tubular clamping member axially guided in the guide bushing and having an annular flange at one end and spaced from said one end an increased diameter portion projecting beyond the guide bushing and provided on its free end with an inner conical face, a lead receiving tube axially guided in the tubular member, a collect connected at one end to the lead receiving tube and having at the other end thereof an outer conical face adapted to cooperate with the inner conical face of the tubular clamping member for clamping a lead in the collet, a tubular slide member guided on its inner surface on the outer surface of the portion of increased diameter of the tubular clamping member and, on its outer surface, on the inner surface of the tubular housing, the slide member projecting with one end beyond one end of the housing, a lead supporting tube carried by the slide member and projecting beyond the one end thereof, an actuating
  • FIG. -1 is an axial cross-section through a mechanical pencil according to the present invention and showing the slide member in retracted position;
  • FIG. 2 is an axial cross-section through the pencil and showing the slide member in advanced position and the collet in open position;
  • FIG. 3 is a partial axial cross-section through the pencil showing the slide member in advanced position and the collet in closed or gripping positionf DESCRIPTION OF THE PREFERRED EMBODIMENT
  • the mechanical pencil according to the present invention comprises tubular housing means composed of a tubular housing rear part 1 and a tubular housing front part 2 having a slightly conical outer surface.
  • the two parts abut with adjacent ends each other and are provided in the region of the adjacent ends with inner screw threads.
  • the two housing parts 1 and 2 are connected to each other at the abutting ends by means of a guide bushing 3 provided at its outer surface with an outer screw thread thread threadingly engaged with the inner screw threads of the housing parts 1 and 2.
  • the bushing 3 has a thin walled coaxial annular extension 4 which engages with a close slide fit a non-threaded inner surface portion of the front housing part 2 to properly centralize the latter with respect to the bushing.
  • a tubular slide member 5 is slidingly guided on the inner surface of the front housing part 2 with a frustoconical portion of the slide projecting beyond the free end of the housing part 2.
  • a small diameter lead support tube 6 is coaxially fastened in any convenient manner in the projecting portion of the slide member 5 and a friction ring 8 is coaxially pressed into a cavity of the slide member rearwardly of the lead support tube 6 for frictionally engaging a lead 7 extending through the tube 6.
  • the slide member In order to limit axial movement of the slide member 5 outwardly of the housing part 2, the slide member is provided at its inner end with an annular radially outwardly projecting flange 9 adapted to cooperate with an inner shoulder 2' on the housing part 2.
  • a clamping tube or tubular clamping member 10 is axially guided in the guide bushing 3.
  • the clamping tube 10 has at its rear end, facing away from the free end of the housing member 2, a stop flange 11 projecting radially outwardly a small distance beyond the outer surface of the clamping tube 10.
  • the clamping tube 10 has a portion 13 of increased outer diameter projecting in axial direction beyond the guide bushing 3 and forming with the remainder of the clamping tube a shoulder adapted to engage an end face 27 of the guide bushing so as to prevent movement of the clamping tube 10 in upward direction, as viewed in FIG. 1, relative to the guide bushing 3, whereas the flange 11 on the inner end of clamping tube 10 prevents movement of the latter in downward direction by engaging the opposite end face 28 of the guide bushing 3.
  • the clamping tube is provided in the region of its flange 11 with a plurality of axially extending slots so that the flange 11, during assembly, may be compressed to a diameter lightly smaller than the bore in the guide bushing, permitting thereby assembly of the clamping tube with the guide bushing.
  • The'clamping tube 10 is provided at the free end of its large diameter portion with an inner frustoconical face 14.
  • the tubular shaft 16 of a collet 15 is axially movable in the tubular clamping member 10, and the collet 15 has an outer conical face adapted to cooperate with the inner conical face at the end of the tubular clamping member 10.
  • the shaft 16 and the collet 15 are in the usual manner provided with longitudinally extending slots 23.
  • the shaft 16 is releasably connected at its end opposite to the end carrying the collet 15 with one end of a lead receiving tube 17.
  • a tubular lead chamber 18 is connected to the other end of the lead receiving tube 17 and the lead chamber is closed by an actuating button 19 releasably connected thereto and projecting beyond the free end of the housing part 1.
  • An insert 20 fitted into a cavity of the actuating button 19 carries a cleaning wire 21.
  • a coil compression spring 22 is arranged about the lead receiving tube 17 and abutting with opposite ends thereof against the chamber 18 and the end face 28 of the guide bushing 3.
  • the collet 15 is moved against the force of the spring 22 toward the lead support tube 6.
  • the tubular clamping member 10 is taken along until the stop flange 11 engages the end face 28 of the guide bushing and, during further movement of the collet 15, the outer conical face thereof will become axially displaced from the inner conical face 14 of the tubular clamping member 10 so that the collet 15 will open.
  • the collet will abut with its end face against the inner end face of the friction ring 8 and move thereby the slide member 5 in axial direction outwardly of the housing member 2 to the position as shown in FIG.
  • a second pressure on the actuating button 19 in the position of the slide member 5 and the tubular clamping member 10 as shown in FIG. 3 will provide an advance of the lead 7.
  • This advance is limited in this case by the distance of the stop flange 11 from the end face 28 of the guide bushing and the lead 7 will thus project beyond the outer end of the lead support tube 6 only for a short distance so that breakage of the lead during writing or drawing will positively be prevented.
  • the lead 7 is supported during writing or drawing by the lead support tube 6 so that a breakage of the lead will be positively prevented.
  • the slide member 5 which carries the lead support tube 6 is moved inwardly into the housing part 2, and the lead may be used up until the flange 9 on the slide member 5 engages the end face 27 of the guide bushing 3. After this condition has been reached, the actuating buttom 19 has to be pressed again in order to advance another portion of the lead.
  • the mechanical pencil according to the present invention will assure that the slide member and the support tube 6 thereon will always project beyond the free end of the inner housing part 2. Therefore, the same conditions will be maintained until the portion of the lead projecting beyond the free end of the support tube is completely used up, which is especially important during use of the pencil in connection with a straight edge.
  • the advancing mechanism can be actuated in any position independent from the movement of the slide member. When the housing part 2 is removed from the housing part 1, the advancing mechanism can be checked in a very convenient manner to ascertain any possible malfunction thereof.
  • the stop flange 11 which accomplishes release of the collet
  • the diameter of the whole advancing mechanism can be held very small while nevertheless assuring a proper clamping and release of the collet.
  • a perfect function of the mechanical pencil is assured by guiding the tubular clamping member in the relatively long bore of the guide bushing, which in turn is properly centered in the front part of the housing by means of the axially extension "of the guide bushing.
  • a mechanical pencil especially for thin leads, comprising, in combination, elongated tubular housing means; a guide bushing in said housing means; a tubular clamping member axially guided in said bushing and having an annular flange at one end and, spaced from said one end, a portion of increased outer diameter projecting beyond said guide bushing and provided on its free end with an inner conical face; a lead receiving tube axially guided in said tubular clamping member; a collet connected at one end to said lead receiving tube and having at the other end thereof an outer conical face adapted to cooperate with said inner conical face for clamping a lead in said collet; a tubular slide member guided on its inner surface on the outer surface of said portion of increased diameter and, on its outer surface, on the inner surface of said tubular housing means, said tubular slide member projecting with one end beyond one end of said housing means; a lead supporting tube carried by said slide member and projecting beyond said one end of the latter; an actuating member projecting beyond the other end of said housing means
  • said biasing means comprises a compression spring about said lead receiving tube and abutting with opposite ends against one end face of said guide bushing and said actuating means.
  • a mechanical pencil as defined in claim ,4 wherein said housing means comprises a front part and a rear part alighned along a common axis, said parts abutting with adjacent ends against each other and being formed in the region of said adjacent ends with inner screw threads, said gude bushing being formed with an outer screw thread threadingly engaged with the inner screw threads of said parts to thus connect the latter to each other.

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  • Mechanical Pencils And Projecting And Retracting Systems Therefor, And Multi-System Writing Instruments (AREA)
US00312117A 1971-12-04 1972-12-04 Mechanical pencil Expired - Lifetime US3813175A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2160306A DE2160306B2 (de) 1971-12-04 1971-12-04 Minenstift mit einer Minenvorschubmechanik

Publications (1)

Publication Number Publication Date
US3813175A true US3813175A (en) 1974-05-28

Family

ID=5827059

Family Applications (1)

Application Number Title Priority Date Filing Date
US00312117A Expired - Lifetime US3813175A (en) 1971-12-04 1972-12-04 Mechanical pencil

Country Status (2)

Country Link
US (1) US3813175A (de)
DE (1) DE2160306B2 (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4153379A (en) * 1977-01-25 1979-05-08 Chao Wen Kuei Knock-out type automatic pencil
US4171170A (en) * 1977-03-31 1979-10-16 Kotobuki & Co., Ltd. Automatic pencil
US4230413A (en) * 1976-10-29 1980-10-28 J. S. Staedtler Mechanical pencil having collet guide
US4247215A (en) * 1977-05-28 1981-01-27 A. W. Faber-Castell Mechanical pencil
US4251163A (en) * 1979-03-21 1981-02-17 Chao Wen Kuei Knock-out type automatic pencil
US4382706A (en) * 1980-05-07 1983-05-10 Ancos Co., Ltd. Mechanical pencil

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5537421Y2 (de) * 1976-10-16 1980-09-02
DE2731330C2 (de) * 1977-07-12 1982-09-23 Gebr. Schmidt, Fabrik für Feinmechanik, 7742 St Georgen Füllminenstift
DE3840760A1 (de) * 1988-12-03 1990-06-07 Faber Castell A W Fuellminenstift

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3724960A (en) * 1970-01-10 1973-04-03 Mitsubishi Pencil Co Ever-sharp pencil with retractable core pipe
US3728033A (en) * 1970-05-06 1973-04-17 Dainihon Bungu Co Ltd Push-type mechanical pencil with improved lead advancing means

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3724960A (en) * 1970-01-10 1973-04-03 Mitsubishi Pencil Co Ever-sharp pencil with retractable core pipe
US3728033A (en) * 1970-05-06 1973-04-17 Dainihon Bungu Co Ltd Push-type mechanical pencil with improved lead advancing means

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4230413A (en) * 1976-10-29 1980-10-28 J. S. Staedtler Mechanical pencil having collet guide
US4153379A (en) * 1977-01-25 1979-05-08 Chao Wen Kuei Knock-out type automatic pencil
US4171170A (en) * 1977-03-31 1979-10-16 Kotobuki & Co., Ltd. Automatic pencil
US4247215A (en) * 1977-05-28 1981-01-27 A. W. Faber-Castell Mechanical pencil
US4352581A (en) * 1977-05-28 1982-10-05 A. W. Faber-Castell Mechanical pencil
US4251163A (en) * 1979-03-21 1981-02-17 Chao Wen Kuei Knock-out type automatic pencil
US4382706A (en) * 1980-05-07 1983-05-10 Ancos Co., Ltd. Mechanical pencil

Also Published As

Publication number Publication date
DE2160306B2 (de) 1974-12-19
DE2160306A1 (de) 1973-07-19

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