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US2158991A - Mechanical pencil - Google Patents

Mechanical pencil Download PDF

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Publication number
US2158991A
US2158991A US85894A US8589436A US2158991A US 2158991 A US2158991 A US 2158991A US 85894 A US85894 A US 85894A US 8589436 A US8589436 A US 8589436A US 2158991 A US2158991 A US 2158991A
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United States
Prior art keywords
clutch
lead
jaws
constricting
guide tube
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US85894A
Inventor
Albert H Stenersen
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Wahl Co
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Wahl Co
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B43WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
    • B43KIMPLEMENTS FOR WRITING OR DRAWING
    • B43K21/00Propelling pencils
    • B43K21/02Writing-core feeding mechanisms
    • B43K21/16Writing-core feeding mechanisms with stepwise feed of writing-cores
    • B43K21/20Writing-core feeding mechanisms with stepwise feed of writing-cores with writing-cores automatically replaced from magazines

Definitions

  • This invention relates to mechanical pencils of the magazine type where the leadsticks are fed one after another from the magazine to the writing point incident/to the normal step-by-step for writing.
  • a general object of the invention is 'the provision of an improved construction for a mechanical pencil of this type which will be reliable and positive in operation and which may'be ⁇ 1Q manufactured economically because of the simplicity and small number of parts involved and the facility with y sembl'ed.
  • a more particular object is the provision of a 15 construction wherein the lead feeding and holding-parts are definitely maintained in proper alignment, to insure proper feed ofthe lead and avoid fracture of the lead stick within the pencil which they may be asincident to the lead feeding operationsY or use of 20. the pencil in writing.
  • vAnother particular object is the provision of an improved construction wherein the parts which grip 'the lead in the lead propelling operation f operate close to theV writing point'of the pencil, so 25 as to minimize possibility -of fracture of the lead stick,A and wherein the weight of the lead sticks is availed of to bestadvantage to insure the feeding of the successive lead sticks from the magazine to the lead gripping parts.
  • Another particular object is the provision of a construction which is particularly qualified for use in pencils wherein the pencil barrel may be formed kof pyroxylin'or similar materials which are desirable because of their decorative or orna- 5 mental'value but which are susceptible to slight distortion or shinkage in they course of time, the
  • Another particular object isfthe provision of a construction whereby the extent to which the 45 lead is propelled in each operation is denitely controlled, and over-feed ⁇ and partial retraction of the lead stick following the propelling movement are obviatecl.
  • yYet another object is the provision of a con- ;50 struction whereby clogging or Jamming of the parts are lead feeding parts are obviated and said x easily accessible for cleaning.
  • Fig. i represents a longitudinal sectional view -of a mechanical pencil representing an embodiment of the invention
  • Fig. 2 ls a similar sectional view of the lower portion of Fig. 1 on a larger scale, showing the parts in normal position; f
  • vFig. 3 is a view similar to Fig. 2 but showing the parts in the positions which they assume at the conclusion of their forward or lead propelling movement;
  • Fig. 4 is an enlarged view of the upper portion of Fig. l;
  • Fig'. 5 is an enlarged view of the pencil tip removed from associated portions of the device
  • Fig. 6 is an enlarged perspective detail of one of the clutch jaws; and 35 Fig. 7 is a longitudinal sectional view illustrat ⁇ ing a slightly modVEd construction.
  • the invention contemplates a lead feeding mechanism which comprises a longitudinally reciprocable tubular element the upper portion of which affords a magazine adapted to hold a number of lead sticks in iside-by-side relationship. and the lower portion of which carries a plurality of gripping jaws adapted to clutch a-lead stick adjacent the point of the pencil.
  • the lead gripping action of the jaws is imparted by a constraining element which exercises .a wedging or camming action on the jaws to press them toward one another, said element being reciprocable to a limited extent with the jaws incident to reciprocation of the tubular member.
  • the cooperation between the Jaws and the constricting member is such that the latter is denitely retained against exerting ⁇ its wedging action upon them ln the course of the return or recessive-movement of the tubular member, and
  • jaws, and the jaw constricting member are ⁇ all I definitely maintained and guided in coaxial rela-V against lateral bending or breaking stresses.
  • the mechanical pencil here illustrated includes a tubular barrel l0, the lower portion of which lenci of the barrel.
  • the guide bushing is slightly tapered and formed with an internal shoulderyor seat I I.
  • a rigid guide bushing I2 is mounted coaxially in the lower end of the barrel, said guide bushing having a peripheral ilange I4 which seats upon the shoulder II.
  • the guide bushing may be secured in the barrel by screw threads, which may be preferable when the barrel is of metal, or it may be secured by 'a pressed nt or in other fashion. It projects out of the truncated lower end of the barrel, the pro jectingr portion affording a screw-threaded part I5 and a centering part I6 winch has a circular peripheral surface.
  • the guide bushing has a cylindrical bore I1 and an enlarged counterbore I8 coaxial therewith. At its upper terminus the bore I1 is slightly flared or funneled, as at ,I9. ⁇
  • the tip 20 is formed of rigid material, such as metal, and is of tapering form, its upper end 4being of a diameter corresponding to the lower
  • the tip has a coaxial stepped bore which forms at its top a. circular aligning portion 2
  • the bore is reduced to form a clutchl chamber 24 which terminates at its upper end at a. shoulder 25.
  • Below the clutch chamber 24 the bore converges in funnel shape, as at 26, to a.
  • a resilient n clamp 30 is fixed in the clamp chamber, said i clamp being of tubular form and springing inwardly at its lower end to a size somewhat less than the end orifice 29.
  • a reciprocable tubular member is provided, same comprising the magazine 3
  • the lower portion of the joining member 34 is provided with a socket in which the upper end of the lead guide tube 32 is fitted and secured, the bore of said lead guide tube being in alignment with an axial aperture 36 of the joining member, which aperture constitutesanv outlet affording passage for lead sticks from the magazine tube into the I lead guide tube.
  • the lower end ofthe lead guide tube is counterf magazine tube.
  • the clutch member is a tubular element which is split longitudinally for a considerable' distance upwardly from its lowerend to provide a plurality of resilient arms 39 which are given a setrthat induces them to assume normally a spread or downwardly diverging relationship.
  • the upper end portion of the clutch member nts accurately in the counterbored portion of the lead guide tube 32 so that itis retained in coaxial relationship therewith.
  • the upper end of the clutch member abuts the shoulder 31 in the lead guide tube, and the lo ⁇ wer end portion of the lead guide tube is swaged inwardly under a shoulder on the clutch member, as at 40, to hold the'clutch member securely and immovably connected with the lead guide tube.
  • They normal bore of theclutch member is slightly smaller than the bore of the lead guide tube.
  • the resilient arms or sections 39 of the clutch member are thickenedrand formed into respective clutch jaws having lead engaging-portions 4I, preferably yserrated or toothed, which extend inwardly beyond the normal inner wall surfaces of the arms, and with peripheral conic or flaring surface portions 42.
  • These flaring surface portions diverge down- .wardly and terminate at their upper ends atabruptly inwardly sloping shoulders 44 -and at their lower ends at downwardly converging conic surfaces 45.
  • 'I'he tubular member is mounted for longitudinal reciprocation within lthe pencil barrel, the lower end portion of the lead guide tube being positioned in the upper portion of the bore of the guide bushing' I2 and accurately guided by said member.
  • a coiled' spring 46 is compressed between the flange I4 vof' the guide bushing and a shoulder 41 of the joining member 34.
  • the vbarrel is internally screw threaded at'48, and a ferrule 49 is screwed therein, said ferrule encompassing the upper end portion of the magazine tube 3l.
  • a clutch constricting member 52 is arranged for longitudinal reciprocatory movement in the The lower portion offthe clutch constricting member 52 is extendeddownwardly beyond the lower y end of the guide bushing I2 in the form of a sleeve 52a having a conic borek that is complementary to the conic peripheral surfaces ⁇ 42 of the clutch jaws.
  • the length of this sleeve is such that it extends for a distance downwardly on the clutch jawswhen the reciprocat'ory tubular member is in its upper limit position. Accordingly, when the tip 'is in position on the guide bushing I2, the clutch jaws and the sleeve 52a extend into the clutch cavity 24.
  • an eraser holder 54 which carries an y eraser 55 projecting from one end thereof, the
  • Either end of the eraser holder may be inserted into the open upper endl of the tube 3
  • the lwall of the tube may be provided with a shallow bayonet groove 51 and the eraser holder with lugs adapted to be received in said groove to retain the holder against accidental displacement.
  • the eraser holder is shown in the 'position wherein the eraser is housed within the upper end portion of the tube 9 I.
  • a gauge member 59 which closes the tube exceptingfor an aperture 59 in said member, said aper- 4ture-,affording the passage through which lead .Kao
  • sticks are introduced into the magazine, and being of size andlshape suchlasv to prevent the introduction of lead sticks of excessive size or improper vform for proper operation in the pencil.
  • the modifled construction shown in Fig. 'l may be employed, inorder to provide the necessary stop for retaining the reciprocable tubular member in the barrel when there is no lead in the clutch, which function is performed by the stops 50 and 5
  • 2a is secured in the j maintained in coaxial alignment with the lower end portion of the lead guide tube by the lower portion of the member
  • 2b forms the upper or rearward limit stop for the clutch constricting member 52.
  • 2b is counterbored at I2c to accommodate movement of a'stop member 5
  • may bein the form of a split spring ring seated in a circumferential groove or kerf in the lead guide tube.
  • the barrel II)y may be made of a material which may be subject to slight warping, the accuracy and certainty of the operation of the'lead feeding mechanism are maintained.
  • a tubular barrel in combination, a tubular barrel, a longitudinally reciprocable tubular member therein,the lower portion 'of said tubular member being in the form of a slender lead guide tube and the upper portion constituting .
  • a magazine of larger diameter than the lead guide tube a clutch member at the lower end of' the tubular member and reciprocable longitudinally therewith, a. clutch constricting member co-- operating with the clutch member and reciprocable longitudinally relative thereto, and an in-l exible guide bushing fixed in the lower portion of the barrel and having guiding cooperation with the clutch constricting member and the lower end portion of the lead guide tube to maintain them in coaxial alignment.
  • a tubular barrel in combination, a tubular barrel, a longitudinally reciprocable tubular member therein, said tubular member having its lower portion in the form of a slender tube adapted to maintain a plurality of lead sticks in single le therein, a clutch member atthe lo'wer therewith, a clutch constricting member encompassing said clutch member and reciprocable longitudinallyrelative thereto, a guide bushing iixed in the lower end of the barrel and having guiding cooperation with said clutch constricting member and the lower end portion of the lead guide tube ⁇ to maintain themv in coaxial alignment; and a tip member aiilxed to said guide bushing at the lower end of the barrel and having an vaxial orifice for passage of a lead stick from the clutch mem'- gber, said guide bushing and tip member havin;r
  • tubular barrel a longitudinally reciprocabetubular membertherein, said tubular member having its lower portion formed as a slender lead guide tube and its upper portion as a magazine of greater .diameter than the'lead guide tube, a clutch member at the lower end of the lead guide tube and reciprocable thereby, a clutch constricting member encompassing the clutch member and reciprocable relative thereto, a guide bushing fixed in the lower portion of the barrel and' Ahaving guiding cooperation with the clutch constricting member and the lower?
  • upper and lower stops 4 for limiting' the reciprocatory movement of said clutch constricting member to a scope less than that of the clutch member, and a stop on the lead guide tube for cooperation with the clutch constricting mem-A ber to -llmitthe downwardmovement of the clutch member.
  • a longitudinally reciprocable tubular member for holding and vconducting lead sticks, a reciprocable clutch for receiving lead sticks lfrom said movement of said jaws in one direction relative y to said constrictlng member, and means for lim- ⁇ iting the reciprocate-ry movement of the constricting member to a scope less than that of the clutch, said clutch having means for latching the constricting member out of jaw-constricting poj ping jaws which are movable outwardly and inwardcly, a constricting member reciprocable with the clutch but through a lesser distancegsaid conv stricting Amember having a portion adapted to wedge the jaws inwardly incident to rearward movement of the jaws relative to .the constricting member, a spring effective on the tubular member to restore it to rearward position after it has been moved frwardlyand means on the clutch for latching the constricting member out of jaw-wedging position during movement.
  • a longitudinallyy reciprocable lead-feeding clutch having an outwardly'spring-pressed lead-gripits rearward ping jaw, a lead guiding member for conducting a lead stick to the clutch, a clutch constricting' member encompassing the clutch and reciprocable therewith, stops limiting the movement of lthe constricting member to only a portion of the stroke of the clutch in each direction, said constricting member adapted to wedge the jaw to lead-gripping position during rearward mov ⁇ ement of the clutch relative vto the constricting member, and said clutch including a catch portion for engagement with the constricting member to hold it out of wedgingcooperation with the jaw during the simultaneous rearward movement of the clutch and'constricting member.
  • a combination as specified in claim Gand wherein the clutch comprises a plurality ofoutwardly spring-pressed 50- to effective position to engage the restricting jaws, each having a catch portion which is moved member upon a predetermined extent of forward movement of the clutch relative to the constricting member.
  • Aa mechanical pencil a combination as Y specified in claim 6 and wherein said jaw is one of a plurality of cooperating jaws which are lspring-pressed outwardly and movable inwardly toward a common axis by the wedging action of the constricting member.
  • a longitudinally reciprocable lead-feeding clutch having an outwardly spring-pressed jaw, a longitudinally reciprocable clutch-constricting mem'-v ber', ⁇ stops for limiting the movement of said constricting member to a distance 'less 'than the stroke of :the clutch in each direction, said. jaw havingY a flaring surface portion adapted forl wedging engagement with the constricting member to cam the Jaw inwardly upon rearward y movement of the clutch relative to the constricting member, saidjaw having also a shoulder sloping abruptly inwardly from the rear terminus of said flaring surface portion; in position to,
  • said jaw is one of a plurality of similar outwardly spring-pressed jaws which are movable inwardly toward a com-y ⁇ laws, a.l longitudinally yreciprocable constricting member encompassing the clutch, stops for limiting the movement of said constricting member to a distance less than the stroke of the clutch in each direction, said jaws having forwardly flaring peripheral surface portions adapted for wedging engagement with the constricting member to camAthe jaws inwardly toward a common axis upon rearward movement of the clutch rela# tive tothe constricting member, said jaws having also lperipheral shoulders sloping abruptly inwardly from vthe rear terminus of said flaring surface portions in position to retentively engage the constricting memberwhen the flaring surface portions are moved forwardly out of engagement therewith, a lead guide tube for guiding a lead stick to an axial position between the jaws, and means for maintaining said
  • a tubular barrel in combination, a tubular barrel, an inflexible guide bushing fixed in the lower end thereof, a longitudinally recip-A of the tubular member, a longitudinally reciproj cable clutch-constricting member associated with said clutch, and a tip having a,bore in which said. clutch operates, said guide bushing having positioning cooperation with said tip and 'said constricting member and the lower portion of said tubular members to maintain them in coaxial alignment.
  • a tubular barrel in combination, a tubular barrel, a lead guide tube reciprocable therein, a clutch reciprocable with the lead guide tube, a reciprocable clutch constricting member, 'I a guide bushing guiding said constricting member and. lthe lower'end of said lead guide tube in coaxial alignment, a stop provided on the lead guide tube for cooperation with the guide bushing to limit rearward movement of the lead guide tube, and a tubular member encompassing the lower end of the lead guide tube and having .its upper endabutting the guide bushing and its lower end aifordlng an abutment for limiting upward movement of the constricting member.
  • a tubular barrel a guide bushing xed in the forward end thereof.
  • a lead guide tube reciprocable in the barrel and extending into and Aguided in said guide bushing.
  • Said guide bushing having an inwardly projecting stop portion, a stop member on the lead guide tube adapted-for cooperanon with saidI stop portion of the hmmag to limit rearward movement of the lead guide tube, clutch jaws reciprocable with the lead guide tube, a clutch constricting member and atubular porytion movably guided in the guide bushing andencompassng the clutch jaws and lower end of the lead guide tube, said tubular portion adapted for abutment with the stop on the guide bushing to limit rearward movement of the cltch constricting member, and a ⁇ spring pressing the lead guide tube rearwardly.

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  • Mechanical Pencils And Projecting And Retracting Systems Therefor, And Multi-System Writing Instruments (AREA)

Description

n 5. propulsion of the i Patented May 1s, l1939 `Ferarri' 'orsi-ca Anm-tn.
MECHANICAL PENCIL Steneraen, Chicago, Ill.. allignor to The Wahl Company, Chicago. Ill., a corporaiion of Delaware if Application :une is, 193s, serai No. sam
f- I 19 Claims.
. This invention relates to mechanical pencils of the magazine type where the leadsticks are fed one after another from the magazine to the writing point incident/to the normal step-by-step for writing.
A general object of the invention is 'the provision of an improved construction for a mechanical pencil of this type which will be reliable and positive in operation and which may'be `1Q manufactured economically because of the simplicity and small number of parts involved and the facility with y sembl'ed. A more particular object is the provision of a 15 construction wherein the lead feeding and holding-parts are definitely maintained in proper alignment, to insure proper feed ofthe lead and avoid fracture of the lead stick within the pencil which they may be asincident to the lead feeding operationsY or use of 20. the pencil in writing.
vAnother particular object is the provision of an improved construction wherein the parts which grip 'the lead in the lead propelling operation f operate close to theV writing point'of the pencil, so 25 as to minimize possibility -of fracture of the lead stick,A and wherein the weight of the lead sticks is availed of to bestadvantage to insure the feeding of the successive lead sticks from the magazine to the lead gripping parts.
' Another particular object is the provision of a construction which is particularly qualified for use in pencils wherein the pencil barrel may be formed kof pyroxylin'or similar materials which are desirable because of their decorative or orna- 5 mental'value but which are susceptible to slight distortion or shinkage in they course of time, the
advantage of the present improvements residing in the fact thatfthe reliability and operabilty of the lead feeding mechanism and the protec- 0 tion of the lead'sticks against fracture are eilectively maintained irrespective of such variations of the pencilbarrel.
Another particular object isfthe provision of a construction whereby the extent to which the 45 lead is propelled in each operation is denitely controlled, and over-feed` and partial retraction of the lead stick following the propelling movement are obviatecl. y f
yYet another object is the provision of a con- ;50 struction whereby clogging or Jamming of the parts are lead feeding parts are obviated and said x easily accessible for cleaning.
Yet another Objectis the provision of a'mechanism having the advantages above specified and 55 which may be embodied in very slender pencils without mcriiice of necessary strength or reliability in operation.
Other and further objects will be pointed out or indicated hereinafter or will be apparent to one skilled in the art upon an understanding of s the invention or its employment in use.
For the purpose of aiding in an explanation of the invention I show in the accompanying drawingiorming a part of this specification, and here- .inafter describe, forms in which the invention lo may be embodied. It is Yto be understood, however, that this is presented for purpose of illustration only, as the invention may be embodied in various other forms, and hence that the example here presented is not to be construed in 15 any fashion for the purpose of, limiting the appended claims short of the true and most comprehensive scope of the invention in the art.
In the drawing,
Fig. i represents a longitudinal sectional view -of a mechanical pencil representing an embodiment of the invention; f.
Fig. 2, ls a similar sectional view of the lower portion of Fig. 1 on a larger scale, showing the parts in normal position; f
vFig. 3 is a view similar to Fig. 2 but showing the parts in the positions which they assume at the conclusion of their forward or lead propelling movement;
Fig. 4 is an enlarged view of the upper portion of Fig. l;
Fig'. 5 is an enlarged view of the pencil tip removed from associated portions of the device;
Fig. 6 is an enlarged perspective detail of one of the clutch jaws; and 35 Fig. 7 is a longitudinal sectional view illustrat` ing a slightly modiiled construction. Y
Described generally, the invention contemplates a lead feeding mechanism which comprises a longitudinally reciprocable tubular element the upper portion of which affords a magazine adapted to hold a number of lead sticks in iside-by-side relationship. and the lower portion of which carries a plurality of gripping jaws adapted to clutch a-lead stick adjacent the point of the pencil. The lead gripping action of the jaws is imparted by a constraining element which exercises .a wedging or camming action on the jaws to press them toward one another, said element being reciprocable to a limited extent with the jaws incident to reciprocation of the tubular member. The cooperation between the Jaws and the constricting member is such that the latter is denitely retained against exerting `its wedging action upon them ln the course of the return or recessive-movement of the tubular member, and
the lower portion of the tubular member, the
jaws, and the jaw constricting member are `all I definitely maintained and guided in coaxial rela-V against lateral bending or breaking stresses.
`imposing lateral bending or breaking pressures on the .contained lead sticks. The improved construction includes other features which, together with the foregoing, will now be described in detail from the illustrative embodiment shown in the drawing.
The mechanical pencil here illustrated includes a tubular barrel l0, the lower portion of which lenci of the barrel.
is slightly tapered and formed with an internal shoulderyor seat I I. A rigid guide bushing I2 is mounted coaxially in the lower end of the barrel, said guide bushing having a peripheral ilange I4 which seats upon the shoulder II. The guide bushing may be secured in the barrel by screw threads, which may be preferable when the barrel is of metal, or it may be secured by 'a pressed nt or in other fashion. It projects out of the truncated lower end of the barrel, the pro jectingr portion affording a screw-threaded part I5 and a centering part I6 winch has a circular peripheral surface. :The guide bushing has a cylindrical bore I1 and an enlarged counterbore I8 coaxial therewith. At its upper terminus the bore I1 is slightly flared or funneled, as at ,I9.`
The tip 20 is formed of rigid material, such as metal, and is of tapering form, its upper end 4being of a diameter corresponding to the lower The tip has a coaxial stepped bore which forms at its top a. circular aligning portion 2| adapted to t the periphery of the aligning portion I6 of the guide bushing, and below that a Vscrew-threaded portion 22 for screwing onto the threaded -portion I5 of the bushing. Below the screw-threaded portion 22 the bore is reduced to form a clutchl chamber 24 which terminates at its upper end at a. shoulder 25. Below the clutch chamber 24 the bore converges in funnel shape, as at 26, to a. clampchamber 21, and at the lower end of the latter again converges at 28 to an end orifice 29. A resilient n clamp 30 is fixed in the clamp chamber, said i clamp being of tubular form and springing inwardly at its lower end to a size somewhat less than the end orifice 29.
A reciprocable tubular member is provided, same comprising the magazine 3| and lead guide tube 32. These are connected in coaxial rela.- tionship by a joining member 34, the upper portion of which is fitted into the magazine tube and is formedwlth a conical top surface 35 which constitutes the bottom of the magazine. The lower portion of the joining member 34 is provided with a socket in which the upper end of the lead guide tube 32 is fitted and secured, the bore of said lead guide tube being in alignment with an axial aperture 36 of the joining member, which aperture constitutesanv outlet affording passage for lead sticks from the magazine tube into the I lead guide tube.
The lower end ofthe lead guide tube is counterf magazine tube.
bored so as to form an internal shoulder 31 (see Fig.' 2) and provide a socket for the clutch member 38. The clutch member is a tubular element which is split longitudinally for a considerable' distance upwardly from its lowerend to provide a plurality of resilient arms 39 which are given a setrthat induces them to assume normally a spread or downwardly diverging relationship. The upper end portion of the clutch member nts accurately in the counterbored portion of the lead guide tube 32 so that itis retained in coaxial relationship therewith. The upper end of the clutch member abuts the shoulder 31 in the lead guide tube, and the lo`wer end portion of the lead guide tube is swaged inwardly under a shoulder on the clutch member, as at 40, to hold the'clutch member securely and immovably connected with the lead guide tube. They normal bore of theclutch member is slightly smaller than the bore of the lead guide tube.
At their lower ends the resilient arms or sections 39 of the clutch member are thickenedrand formed into respective clutch jaws having lead engaging-portions 4I, preferably yserrated or toothed, which extend inwardly beyond the normal inner wall surfaces of the arms, and with peripheral conic or flaring surface portions 42. These flaring surface portions diverge down- .wardly and terminate at their upper ends atabruptly inwardly sloping shoulders 44 -and at their lower ends at downwardly converging conic surfaces 45. v
'I'he tubular member is mounted for longitudinal reciprocation within lthe pencil barrel, the lower end portion of the lead guide tube being positioned in the upper portion of the bore of the guide bushing' I2 and accurately guided by said member. A coiled' spring 46 is compressed between the flange I4 vof' the guide bushing and a shoulder 41 of the joining member 34. At its upper end the vbarrel is internally screw threaded at'48, and a ferrule 49 is screwed therein, said ferrule encompassing the upper end portion of the magazine tube 3l. .Said ferrule has an inwardly jutting shoulder 5ll'which overhangs an outwardly projecting stop member 5I `on the Thus the ferrule retains the reciprocable tubular member against withdrawal fromthe barrel and has guiding cooperation with it in its reciprocatory movement. With the reciprocable tubular member thus assembled in the barrel, the clutch jaws project somewhat beyond the lower end of the guide bushing I2.
` A clutch constricting member 52 is arranged for longitudinal reciprocatory movement in the The lower portion offthe clutch constricting member 52 is extendeddownwardly beyond the lower y end of the guide bushing I2 in the form of a sleeve 52a having a conic borek that is complementary to the conic peripheral surfaces`42 of the clutch jaws. The length of this sleeve is such that it extends for a distance downwardly on the clutch jawswhen the reciprocat'ory tubular member is in its upper limit position. Accordingly, when the tip 'is in position on the guide bushing I2, the clutch jaws and the sleeve 52a extend into the clutch cavity 24.
On the upper endy of the magazine tube 3| is mounted an eraser holder 54 which carries an y eraser 55 projecting from one end thereof, the
otherend being closed.` Either end of the eraser holder may be inserted into the open upper endl of the tube 3| to the extent permitted by a periphyeral ilange 56 formed on thel eraser holder and yadapted to abut the upper end of the tube 3|.
The lwall of the tube may be provided with a shallow bayonet groove 51 and the eraser holder with lugs adapted to be received in said groove to retain the holder against accidental displacement. In Fig. 4 the eraser holder is shown in the 'position wherein the eraser is housed within the upper end portion of the tube 9 I. In the re' a gauge member 59, which closes the tube exceptingfor an aperture 59 in said member, said aper- 4ture-,affording the passage through which lead .Kao
sticks are introduced into the magazine, and being of size andlshape suchlasv to prevent the introduction of lead sticks of excessive size or improper vform for proper operation in the pencil.
- This also acts as a lead retaining closure for the upper end4 of the magazine. y
In the operation of the pencil, a plurality o f f lead sticks L having been disposed in the maga'- zine tube 3|, some of them will be fed by gravityv into the vlead guide tube 32. when the pencil is held with the' point downwardly. 'I'he lowermost lead stick will be stopped by the clutch jaws, which will be held in inward position by the sleeve 52a.
Pressure being applied to the upper end4 of the eraser. holder, the tubular member will be moved downwardly against the pressure of spring 49. The clutch constricting member 52 will be carried downwardly `with the tubular member be- 'cause of thegfrictional engagement of the sleeve 52a' with the peripheral surfaces -of' the clutch jaws whichy are urged radially routwardly by the` tension of the resilient arms 39. 4Such downward movement of the clutch, constricting member will continue untilits. shoulder 53 engages shoulder 25 of the tip; Downward movement of the tubular .member continues, howeveruntil it isar'rested by engagement of its stop 4D with the upper end of the clutch constricting member 52. Incident to such further downward movement of ythe tubular member the conic peripheral surfaces 42 of the clutch jaws are moved beyond the lower i end of the sleeve 52a, andthe jaws Aare thus per- .mit.tedf to spring outwardly tol ya position such as shown in Fig. 3. 'I'his permits lthe lowermost lead stick to slide down until it is stopped in the clamp 30, such downward movement of the lw- `ermost lead stick being aided by the weight of the following lead sticks in the leadyguidetube 32'.
It will be observed, as in Fig. 3, that the further downward movementof the tubular member, after the clutch 'constricting member 52 has been stopped, brings the abruptly sloping shoulders 44 to a position beyond or below the lower end of the sleeve 52a. Accordingly, when the d ownward pressure on the eraser holder is relieved so as to permitthe spring 49 to move the tubular and more or less of the conic surfaces 42 ofthe vclutch jaws into the sleeve 52 and camming or wedging the clutch jaws inwardly against the spring pressure oi their arms 39. This inward movement oi' the jaws continues until the lead engaging members 4| engage the lead stick, which normally will occur before the stop (Fig. 4) reaches the stop shoulder 50 of the ferrule 49 and while the spring 49 remains partially com.
pressed. Consequently, the parts are maintained at rest against the pressure of spring 46 through the medium of the clutch constricting member 52 and its wedging cooperation with the clutchv jaws. 'I'his induces a very firm clutching engagement of 'member upwardly, the clutch constricting mem- However, when the jaws with the lead stick. Consequently, when the tubular member is again pressed downwardly, the lead stick will be carried downward with the jaws and propelled through the restricted.
portion of the resilient clamp 30, which thereupon clamps the lead stick and holds it definitely against retraction. By such repeated operations of the reciprocable tubular member the lead stick is propelled step by step through the writing tip of the pencil: As soon as one lead stick is ejected,4 the next one follows on. immediately, step by step, this continuing until the magazine tube and lead guide tube havebeen completely emptied A,of lead sticks. When there is no lead stick engaged in the clutch, thetubular member is retained against withdrawal from the barrel by engagement of the stop 5| with stop 50 of the ferrule, and the resulting additional projection of the tube 3| above the upper end of the ferrule serves an indication that the clutch is unoccupied.
In some instances it may be desirable to avoid thev use of `the separate ferrule 49 at the upper end of the barrel. In such instances the modifled construction shown in Fig. 'l may be employed, inorder to provide the necessary stop for retaining the reciprocable tubular member in the barrel when there is no lead in the clutch, which function is performed by the stops 50 and 5| in the form above described. In this modified construction the guide bushing |2a is secured in the j maintained in coaxial alignment with the lower end portion of the lead guide tube by the lower portion of the member |2a.v The lower end of the member |2b forms the upper or rearward limit stop for the clutch constricting member 52. The upper portion of Athe member |2b is counterbored at I2c to accommodate movement of a'stop member 5| incident to longitudinal movement-of the lead guide tube. This stopmember 6| may bein the form of a split spring ring seated in a circumferential groove or kerf in the lead guide tube. When there is a lead stick engaged inthe clutch, the lead guide tube will normally be arrested inthe position-shown in Fig. 7, the stop member 6I being some distance from the stop I3. However, when there is no lead stick in the I clutch, and the clutch` jaws as a consequence may move inward to such an extent that the rearwardmovement of the clutch is not arrested by i the constricting member 52, the tubular memzwthe member I.2a. Then the split ring 5l S Placed in the groove, and the member I2b telescoped over the clutch and the lower end vof the lead guide tube and into the member I2a, after which the constricting member 52 is telescoped over the clutch and intok the lower end of the member I2a.
Certain particular advantages of the construction are to be observed.` It will be noted that due to the engagement of the sleeve 52a above the shoulders 44 of the clutch jaws, the clutch constricting member will be positively propelled on return movement of the reciprocatory tubular member, and premature clamping of the lead stick will be thereby prevented, thus avoiding retraction of the lead stick. It will also be notedthat the guide bushing I2 forms a definitevaiigning guide for the lower end of the lead guide tube 32 and the clutch constricting member 52, holding them accurately in coaxial relationship. This insures the proper concentric actionof the4 clutch jaws and prevents anyeccentric displacement of the lead propelling parts such as might impose lateral breaking stresses on the lead stick which is held in the clutch. 'I'his coaxial alignment of the lead propelling partswith the clamp 30 and tip orifice 29 is maintained by the centering guide afforded by cooperation of the fitting surfaces I6 and 2| of theguide bushing and tip respectively as Well as by the screw-thread connection oi the tip with the lower end portion of the guide bushing. Consequently, even though' the barrel II)y may be made of a material which may be subject to slight warping, the accuracy and certainty of the operation of the'lead feeding mechanism are maintained.' The provision of the inwardly projecting lead-engaging portions II of the clutch jaws aiords suiicient'clearance between the arms 39 and the leadstick to permit the initial lead ,stick/'to feed freely bygravity when the jaws are in their opened or cast-ofi. position, and the provision of the abrupt shoulders IVI on the jaws per-f sitioned with its point upwardly land he reciprocatory tubulary member held in its inward posi tion; the tip may be unscrewed and removed,
carrying the clamped lead stick with it, such removal aii'ording access to the lead handling parts for' purpose of cleaning., By thu's removing the tip and unscrewing the ferrule 49, all of the operating parts may be removed from the barrel.
u wmtrclaimis:
1. In a mechanical pencil, in combination, a tubular barrel, a longitudinally reciprocable tubular member therein,the lower portion 'of said tubular member being in the form of a slender lead guide tube and the upper portion constituting .a magazine of larger diameter than the lead guide tube, a clutch member at the lower end of' the tubular member and reciprocable longitudinally therewith, a. clutch constricting member co-- operating with the clutch member and reciprocable longitudinally relative thereto, and an in-l exible guide bushing fixed in the lower portion of the barrel and having guiding cooperation with the clutch constricting member and the lower end portion of the lead guide tube to maintain them in coaxial alignment.
2. In a mechanical pencil, in combination, a tubular barrel, a longitudinally reciprocable tubular member therein, said tubular member having its lower portion in the form of a slender tube adapted to maintain a plurality of lead sticks in single le therein, a clutch member atthe lo'wer therewith, a clutch constricting member encompassing said clutch member and reciprocable longitudinallyrelative thereto, a guide bushing iixed in the lower end of the barrel and having guiding cooperation with said clutch constricting member and the lower end portion of the lead guide tube `to maintain themv in coaxial alignment; and a tip member aiilxed to said guide bushing at the lower end of the barrel and having an vaxial orifice for passage of a lead stick from the clutch mem'- gber, said guide bushing and tip member havin;r
concentric guide surfaces cooperating to position the tip member in coaxial `relationship with, the clutch constricting member.
end of said lead guide tube and reciprocable 3. In a mechanical pencil, in combination, a
`vtubular barrel, a longitudinally reciprocabetubular membertherein, said tubular member having its lower portion formed as a slender lead guide tube and its upper portion as a magazine of greater .diameter than the'lead guide tube, a clutch member at the lower end of the lead guide tube and reciprocable thereby, a clutch constricting member encompassing the clutch member and reciprocable relative thereto, a guide bushing fixed in the lower portion of the barrel and' Ahaving guiding cooperation with the clutch constricting member and the lower? end of the lead guide tube to maintain them in coaxial alignment, upper and lower stops 4for limiting' the reciprocatory movement of said clutch constricting member to a scope less than that of the clutch member, and a stop on the lead guide tube for cooperation with the clutch constricting mem-A ber to -llmitthe downwardmovement of the clutch member.
4. In a mechanical pencil, in combination, a longitudinally reciprocable tubular member for holding and vconducting lead sticks, a reciprocable clutch for receiving lead sticks lfrom said movement of said jaws in one direction relative y to said constrictlng member, and means for lim-` iting the reciprocate-ry movement of the constricting member to a scope less than that of the clutch, said clutch having means for latching the constricting member out of jaw-constricting poj ping jaws which are movable outwardly and inwardcly, a constricting member reciprocable with the clutch but through a lesser distancegsaid conv stricting Amember having a portion adapted to wedge the jaws inwardly incident to rearward movement of the jaws relative to .the constricting member, a spring effective on the tubular member to restore it to rearward position after it has been moved frwardlyand means on the clutch for latching the constricting member out of jaw-wedging position during movement. 6; In a mechanical pencil, in combination, a longitudinallyy reciprocable lead-feeding clutch having an outwardly'spring-pressed lead-gripits rearward ping jaw, a lead guiding member for conducting a lead stick to the clutch, a clutch constricting' member encompassing the clutch and reciprocable therewith, stops limiting the movement of lthe constricting member to only a portion of the stroke of the clutch in each direction, said constricting member adapted to wedge the jaw to lead-gripping position during rearward mov`ement of the clutch relative vto the constricting member, and said clutch including a catch portion for engagement with the constricting member to hold it out of wedgingcooperation with the jaw during the simultaneous rearward movement of the clutch and'constricting member.
'1. In a mechanical pencil, a combination as specified in claim 6 and wherein said catch is spring-pressedto position for engagement with the constricting member when the clutch approaches its limit of forward movement.v 8. In a mechanical pencil, acombination as specified in claim 6 and wherein said catch is movable inwardly and outwardly with the jaw.
9.y In a mechanical pencil, a combination as.
specified in claim 6 and wherein said catch is lmovable to ineffective position by rearward movement of thev clutch relative to the constricting member after the latter has reached its limit of rearward movement.
10. In a mechanical pencil, a combination as specified in claim Gand wherein the clutch comprises a plurality ofoutwardly spring-pressed 50- to effective position to engage the restricting jaws, each having a catch portion which is moved member upon a predetermined extent of forward movement of the clutch relative to the constricting member.
11. In Aa mechanical pencil, a combination as Y specified in claim 6 and wherein said jaw is one of a plurality of cooperating jaws which are lspring-pressed outwardly and movable inwardly toward a common axis by the wedging action of the constricting member.
12. In' a mechanical pencil, in combination, a longitudinally reciprocable lead-feeding clutch )having an outwardly spring-pressed jaw, a longitudinally reciprocable clutch-constricting mem'-v ber',`stops for limiting the movement of said constricting member to a distance 'less 'than the stroke of :the clutch in each direction, said. jaw havingY a flaring surface portion adapted forl wedging engagement with the constricting member to cam the Jaw inwardly upon rearward y movement of the clutch relative to the constricting member, saidjaw having also a shoulder sloping abruptly inwardly from the rear terminus of said flaring surface portion; in position to,
engage a forwardly facing margin lof the constricting member when the flaring surface por- `tion is moved forwardly therebeyond.
i3. In a mechanical pencil, a combination as specified in claim 12 and wherein said jaw is one of a plurality of similar outwardly spring-pressed jaws which are movable inwardly toward a com-y `laws, a.l longitudinally yreciprocable constricting member encompassing the clutch, stops for limiting the movement of said constricting member to a distance less than the stroke of the clutch in each direction, said jaws having forwardly flaring peripheral surface portions adapted for wedging engagement with the constricting member to camAthe jaws inwardly toward a common axis upon rearward movement of the clutch rela# tive tothe constricting member, said jaws having also lperipheral shoulders sloping abruptly inwardly from vthe rear terminus of said flaring surface portions in position to retentively engage the constricting memberwhen the flaring surface portions are moved forwardly out of engagement therewith, a lead guide tube for guiding a lead stick to an axial position between the jaws, and means for maintaining said constricting member in coaxial alignment with the lead guide tube.
15. In a mechanical pencil, in combination, a tubular barrel, an inflexible guide bushing fixed in the lower end thereof, a longitudinally recip-A of the tubular member, a longitudinally reciproj cable clutch-constricting member associated with said clutch, and a tip having a,bore in which said. clutch operates, said guide bushing having positioning cooperation with said tip and 'said constricting member and the lower portion of said tubular members to maintain them in coaxial alignment.v
16. In a mechanical pencil, a combination as specified in claim 15 and wherein the clutch has a plurality of outwardly spring-pressed jaws and the constricting member is adapted for wedging cooperation with said jaws to move them inwardly toward the axis of the guide bushing.
17. In a'mechanical pencil, in combination, a tubular barrel, a lead guide tube reciprocable therein, a clutch reciprocable with the lead guide tube, a reciprocable clutch constricting member, 'I a guide bushing guiding said constricting member and. lthe lower'end of said lead guide tube in coaxial alignment, a stop provided on the lead guide tube for cooperation with the guide bushing to limit rearward movement of the lead guide tube, and a tubular member encompassing the lower end of the lead guide tube and having .its upper endabutting the guide bushing and its lower end aifordlng an abutment for limiting upward movement of the constricting member.
18. In 'a mechanical pencil, in combination, a tubular barrel, a guide bushing xed in the forward end thereof. a lead guide tube reciprocable in the barrel and extending into and Aguided in said guide bushing. Said guide bushing having an inwardly projecting stop portion, a stop member on the lead guide tube adapted-for cooperanon with saidI stop portion of the hmmag to limit rearward movement of the lead guide tube, clutch jaws reciprocable with the lead guide tube, a clutch constricting member and atubular porytion movably guided in the guide bushing andencompassng the clutch jaws and lower end of the lead guide tube, said tubular portion adapted for abutment with the stop on the guide bushing to limit rearward movement of the cltch constricting member, and a `spring pressing the lead guide tube rearwardly.
19. In a mechanical pencil, in combination, a. tubular barrel, a guide bushing iixed therein, a
m longitudinally reciprocable clutch constricting member guided by the guidel bushing, 'a clutch reciproeable in said clutcbconstricting member and having an outwardly spring-pressed jaw adapted to be wedged inwardly thereby at the end ofthe rearward movement of the clutch, said jaw` having a catch portion adapted .toeng'age said clutch constricting member after the clutch has been moved forwardly relative thereto and to restrain the clutch constricting member out of jawwedging position throughout the rearward movement of the ch'ltch constricting member.
AIBERT H. STENERSEN. l
US85894A 1936-06-18 1936-06-18 Mechanical pencil Expired - Lifetime US2158991A (en)

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2427648A (en) * 1939-12-14 1947-09-16 Farrington Hastings Macleod Propelling pencil
US2561113A (en) * 1948-05-03 1951-07-17 Henry T Hallberg Gravity and inertia fed pencil
US2563551A (en) * 1951-08-07 Pencil
US2564727A (en) * 1948-04-07 1951-08-21 Seripto Inc Mechanical pencil
US2627842A (en) * 1948-03-31 1953-02-10 Raymond T Moloney Mechanical pencil of the push-button type
US3439989A (en) * 1966-09-09 1969-04-22 Parker Pen Co Automatic pencil
US4205924A (en) * 1978-11-17 1980-06-03 Pilot Precision Kabushiki Kaisha Mechanical pencil with lead-feeding device operable by forward shake of pencil
US4729684A (en) * 1985-07-18 1988-03-08 Micro Co., Ltd. Mechanical pencil

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2563551A (en) * 1951-08-07 Pencil
US2427648A (en) * 1939-12-14 1947-09-16 Farrington Hastings Macleod Propelling pencil
US2627842A (en) * 1948-03-31 1953-02-10 Raymond T Moloney Mechanical pencil of the push-button type
US2564727A (en) * 1948-04-07 1951-08-21 Seripto Inc Mechanical pencil
US2561113A (en) * 1948-05-03 1951-07-17 Henry T Hallberg Gravity and inertia fed pencil
US3439989A (en) * 1966-09-09 1969-04-22 Parker Pen Co Automatic pencil
US4205924A (en) * 1978-11-17 1980-06-03 Pilot Precision Kabushiki Kaisha Mechanical pencil with lead-feeding device operable by forward shake of pencil
US4729684A (en) * 1985-07-18 1988-03-08 Micro Co., Ltd. Mechanical pencil

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