US3179089A - Mechanical pencil assembly - Google Patents

Description

April 20, 1965 J. A. clvlrAREsE MECHANICAL PENCIL ASSEMBLY 2 Sheets-Sheet 1 Filed April 23 1963 FIG. 2

INVENTOR JOSEPH A. c/v/TARESE jmd/@ ATTORNEYS April 20, 1965 J. A. clvlTAREsE MECHANICAL PENCIL ASSEMBLY 2 Sheets-Sheet 2 Filed April 25 1963 FIG. 5

FIG. 6

INVENTOR JOSEPH A. c/v/mREsE ATTORNEY` United States Patent O 3,179,089 MECHANICAL PENCIL ASSEMBLY Joseph A. Civitarese, 69 Park Ave., lLodi, NJ. Filed Apr. 23, 1963, Ser. No. 274,959 7 Claims. (Cl. 1Z0- 98) The present invention relates to pencils and more particularly to mechanical pencils of the type used in engineering drafting.

In pencilling engineering drawings and the like, it is highly desirable to manually rotate the pencil while drawing a line to keep the pencil point sharp for a longer period of time. This practice of manually rotating the pencil, in addition to reducing the frequency at which the pencil requires resharpening, provides clean-cut lines of uniform thickness to improve the appearance of the draw- To assist draftsmen in maintaining a sharp conical pencil point, various lead-rotating devices have been proposed but all have been found to be inadequate for one reason or another. For instance, some conventional pencil holders have a manually depressible end element for rotating the lead when the pencil is lifted from the drawing surface. Such devices, however, in requiring the draftsman to lift the pencil from the drawing when he desires to rotate the lead, do not offer the advantages derived from continuously rotating the pencil while a line is being drawn. As a consequence, the pencil point will objectionably wear non-uniformally in the course of drawing a line unless the draftsman resorts to the usual practice of rotating the pencil as he draws.

In accordance with the present invention, the necessity of rotating the pencil by hand in the course of drawing a line is eliminated by use of a drive mechanism having freely rotatable friction wheel particularly adapted to run onta T-square or triangle for automatically effectuating continuous rotation of the lead-holding collet. The lead rotating friction wheel of the invention may also be used as an effective means for sharpening the pencil point.

With the foregoing considerations in mind, it is, therefore, the primary object of the present invention to provide a novel pencil device for automatically effecting the continuous rotation of the pencil lead while a line is being drawn.

Amore specific object of the present invention resides in the provision of a novel mechanical pencil assembly having a surface engaging friction wheel drive for rotating the pencil lead.

Another specific object of the present invention `is to provide a novel mechanical pencil assembly having a rotatably mounted lead piece, a rotatable friction wheel adapted to engage a flat surface such as a T-square or triangle, `and a motion transmitting train for imparting rotary motion of the wheel to cause continuous rotation of the lead piece while a line is being drawn.

Further objects of the invention will appear as the description proceeds in connection with the appended claims and the annexed drawings wherein:

FIGURE 1 is a side elevation of a mechanical pencil constructed according to a preferred embodiment of the present invention;

FIGURE 2 is a front elevation of the mechanical pencil illustrated in FIGURE l;

FIGURE 3 is a longitudinal section taken substantially along lines 3 3 of FIGURE 2;

FIGURE 4 is a section taken substantially along lines 4*@ of FIGURE l;

FIGURE 5 is a sectional view taken substantially along lines 5 5 of FIGURE 4;

ilddd Patented Apr. 20, 1965 lCe FIGURE 6 is an enlarged fragmentary side elevation particularly illustrating the friction wheel mounting sleeve shown in FIGURE 2;

FIGURE 7 is an enlarged fragmentary front elevation of the mounting sleeve `illustrated in FIGURE 6;

FIGURE 8 is a section taken substantially along lines -S of FIGURE 7.

Referring now to the drawings and more particularly to FIGURES l-3, the reference numeral lil generally designates a mechanical drafting pencil incorporating the principles of the present invention and comprising a nose piece Il formed with a rearwardly opening internally threaded bored recess 12 which threadedly and coaxially receives the forward end of a tubular spindle 14.

As best seen from FIGURE 3, spindle 14 is coaxially and rotatably received in a smooth cylindrical bore 17 formed in a tubular casing I3 that is open at both ends. Casing 1S is axially retained in place between radially extending annular axially opposed faces ZZ and 24 respectively formed on nose 11 and an end plug 2d. End plug 26 has a forwardly extending externally threaded reduced diametered portion 27 coaxially and threadedly received in the rearward end of spindle ld. Casing 18, spindle 14 and nose 11 are thus axially secured together as a unit with nose 11, spindle 14 and plug 26 being rotatable as a unit relative to casing I8 for a purpose to be `presently explained.

With continued reference to FIGURE 3, nose 1I is formed with a coaxial through bore 23 extending rearwardly from the pencil tip to recess 12. A one-piece collet 3b extends coaxially through bore 28 and through recess 12 and into spindle 14. Collet 30 is provided with a tubular shank portion 31 having a plurality of longitudinal circumferentially spaced apart slits 32 extending rearwardly from the forward tip thereof. Slits 32 terminate about midway between the ends of collet 3d to provide a plurality of circumferentially disposed conventionally formed flexible lead gripping spring prongs 36 extending axially through bore 28. Each of the prongs 36 is formed with an externally tapered portion 38 located intermediate the ends of shank portion 31 .and providing a gradually increasing collet diameter extending toward the forward end of nose Il.

When an elongated cylindrical pencil lead 46 (FIGe URES l and 2) is inserted through collet 3l), it radially spreads prongs 36 in the usual manner to force the tapered portions 33 into tight bearing engagement with a section 42 of bore 23 which is gradually tapered in the same direction as prong portions 38 for a purpose to be explained in detail later on.

With continued reference to FIGURE 3, collet Sil is formed at its rearward end with an enlarged diametered cylindrically shaped head 46 integrally joined to shank portion 3l and slidably received in spindle le. Head 4d is provided with an internally threaded recess 43 facing axially rearwardly and threadedly receiving the forward end of an operating tube Sil. Tube 5t) is coaxially received in spindle 14 in radially spaced relationship to the internal spindle periphery.

A cylindrical lead release member 52 engaging the rearward end of tube 5d is stepped providing reduced diametered end sections 54 and 55 integrally joined by an intermediate section 58 of larger diameter. Section 5S is axially disposed between tube SQ and plug portion 27 and provides an annular axially facing shoulder 59 against which the rearward end of tube 5t) bears. Normally urging section 58 into abutment with plug 26 is a coiled compression spring 60.

snr/apes Spring 60 is disposed in an annular space 62 in coaxial surrounding relationship to the collet shank portion 31 and reacts between opposed axially facing annular shoulders 64 and 66 respectively formed on the collet head 46 and nose 11 at the base of recess 12 to axially urge tube Sti rearwardly into bearing engagement with shoulder 59 on release member 52.

With continuing reference to FIGURE 3, section 54 slidably extends through a smooth cylindrically walled )bore 68 formed coaxially through plug 2e in alignment with the longitudinal axis of casing '13. Section Se coaxially extends into the rearward end of tube t? to maintain tube 50 in coaxially radially spaced apart relation ship to the inner periphery of spindle 14. Section 54 projects axially beyond end plug 26 and is manually depressible in opposition to the bias exerted by spring 60 to axially `shift tube Sti and collet 311 forwardly as a unit.

When lead 41B is disposed in collet 311, prongs 36 grip the lead and are radially spread in the manner shown in FIGURE 3 such that tapered portions 38 seat snugly against lthe tapered wall surface of the nose bore section 42. Spring 6i) reacting against nose 11 urges collet 30 rearwardly to firmly wedge the collet in nose 11 with the forward ends of prongs 36 projecting beyond the nose as shown. By wedging collet 31B in place with nose 11, both of these parts are therefore rotatable as unit for a purpose to be presently explained and the prongs 36 are flexed radially inwardly to iixedly grip lead 4i) and axially retain it in the drawing position illustrated in FIGURES 1 and 2.

In order to remove lead 40, member 52 is depressed axially shifting collet 30 forwardly from the position shown in FIGURE 3 to an extended position where prongs 36 are free to flex radially outwardly to resume normal unbiased positions where they release lead 40. Lead 4t) is then free to be pulled out of the pencil. This action of gripping and releasing lead 40 with collet 31) in itself, is generally conventional and, consequently, need not be explained further.

In accordance with the present invention, collet 31B together with lead 4t) therein, nose 11 and spindle 14 are rotatable as a unit relative to casing 18 by means of a surface engaging friction wheel assembly '70 (FIGURES l and 2) and amotion transmitting gear train '72 (FIG- URE 2). l

As best shown in FIGURE 4, friction wheel assembly 'itl comprises hub 74 preferably made of molded plastic and formed with a radially outwardly opening rounded bottom peripheral groove Sil which snugly receives an annular tire 82 made of suitable resilient material such as rubber. A screw member 34 mounting wheel assembly 7) extends at right angles to the common longitudinal axis of spindle 14 and nose 11 and has an enlarged head 86 and a smooth intermediate cylindrical section 88. Hub 74 is non-rotatably mounted coaxially on section S8 and is axially conned in place between head 86 and .a rigid annular spacer 9i). Section 88 of screw member 84 is journalled in spacer 90 and terminates axially beyond spacer 90 is a reduced diametered threaded end section 92 which receives a nut and washer assembly 94, the washer of which axially bears against an annular shoulder 95 formed on member S4 at the juncture of sections 83 and 92.

With continued reference to FIGURES 4 and 5, wheel assembly 70, member 84 and spacer 911 are carried as a unit by a flat sided mounting arm 96 having a noncircular aperture 9S delimited by an annular lip 11i@ which is snugly received in a radially outwardly opening flat bottomed groove 102 formed in the outer periphery of spacer 911 in the manner shown. Spacer 9@ th-us is non-rotatably carried by arm 96 and journals screw member S4 which is rotatable by wheel assembly 711. Arm 96 is laterally spaced to one side of casing 1? and extends parallel to the pencil assembly longitudinal axis with l wheel assembly 70 being located on the side of arm 96 facing away from casing 13.

With continuing reference to FIGURE 4, arm 96 is rockably mounted about the pivot axis of a fixed screw member 1114 extending in parallel spaced apart relationship to and above screw member 84. Member 104 is provided with a smooth cylindrical intermediate section 106 extending through an aperture formed in arm 96. At axially opposite ends of section 1116, screw member 1114 is formed with an enlarged head 108 and a reduced diametered threaded end section 111i.

In order to mount screw member 1514, a mounting sleeve 112 slidably receiving and carried by casing 1S has a transverse internally threaded boss portion 113 coaxially receiving end section 110. Sleeve 112 and casing 18 are advantageously provided with mating noncircular peripheries of hexagon configuration to prevent sleeve 112 from rotating relative to easing 18.

As best shown in FIGURES 6 8, sleeve 112 is mounted at the forward end of casing 18 immediately above nose 11 and is integrally formed with a mounting clip 114 of flexible spring strip material extending from the lower forward end of sleeve 112 and being looped rearwardly to longitudinally lie over sleeve 112. Axially beyond the rearward end of sleeve 112, clip 114 is formed with a pair of inwardly turned prongs 116 which are biased to radially and snugly extend into a flat bottomed outwardly opening annular groove 113 formed in the periphery of casing 1S.

In the assembly, with prongs 111i fitted into groove 11S,

' it is clear that sleeve 112 is axially and non-rotatably mounted on casing 18. To remove sleeve 112, clip 114 is formed with a tab 121i which extends rearwardly between prongs 116 and which can be gripped to pull clip 114 outwardly and thus Withdraw prongs 116 from groove 118. Sleeve 112, arm 96, Wheel assembly 70 and gear train 72 then are conveniently removable as a unit from the pencil assembly by sliding sleeve 112 rearwardly along casing 18.

As sho-wn in FIGURES 2, 4, 7 and 8, sleeve 112 is integrally provided with a laterally protruding mounting bracket portion 122 having a ilat-sided cross piece 123 laterally spaced from casing 1S and formed with an aperture snugly receiving a screw 124 which extends along an axis that is parallel to and above the axis of screw member 105. Screw 124 extends freely through an arcuate slot 126 (FIGURE 1) formed in the upper end of arm 96 and is threaded into blind tapped bore formed in a peripherally knurled adjustment knob 123 located on the side of arm 96 facing away from casing 1S. The radius of slot 126 has its center coincident with the fixed pivot axis of screw member 113-6. The upper end of arm 96 is clamped tightly between cross-piece 123 and knob 12S when the latter is tightened to the position shown in FIGURE 4.

By loosening knob 123, arm 96 is swingable in either direction about the xed pivot axis of screw member 1116 to selectively vary the linear distance between the periphery of the surface engaging tire 32 and the tip of nose 11. This adjustment assures that tire 32 will engage a 4desired surface when the pencil assembly is held by the draftsman in a selected linclined position with the point of lead 41B touching a drawing surface 129 as shown, for example, in FIGURE 2.

As best shown in FIGURES 2 and 4, gear train 72 comprises a pair of bevel gears 132 and 134 and a pair of spur gears 13d and 13S. Gear 132 is formed at the rearward end of an internally longitudinally splined elongated hub section 14@ which is non-rotatably mounted on an externally splined recessed section 142 formed on the upper part of nose 11. The forward end face of hub section 1413 snugly and interfittingly abuts against an annular shoulder 143 (FIGURE 3) formed on nose 11 to axially locate and prevent forwardV displacement Y of gear 132.

With continued reference to FIGURES 2 and 4, gears 134 and 136 are iixedly and coaxially mounted side by side on a hub 146 which is journalled on section 106 of screw member 104 and which is axially retained between boss portion 113 and the'surface of arm 96 facing toward casing 18. Gears 134 and 136 respectively constantly mesh with gears 132 and 138. Gear 138 is axially coniined between assembly 94 and spacer 90 and is nonrotatably carried on a non-circular portion of section 88 having oppositely facing flat milled lands 139 (one Shown). The central aperture of gear 138 is provided with a non-circular configuration corresponding to the portion of section 88 containing lands 139. Rotation of friction wheel assembly 70 thus rotates gears 138, 136, 134 and 132 to effectuate rotation of nose 11. Casing 18 when grasped by the draftsman will be held against rotation.

In drawing with pencil assembly 10, friction wheel 70 is adjusted about the axis of member 164 in the manner previously described to engage the iiat surface of a pencil guide duafting implement 150 such as, for example, a T-square or triangle, when lead 40 is contacting the surface 129 in inclined drawing position as shown in FIG- URES l and 2. As the draftsman draws a line with pencil assembly positioned in this manner, friction wheel 70 will run along implement 15d and thus will be rotated about the axis of member S4. Rotation of wheel 70 is transmitted through gear train 7 2 to continuously rotate nose 11. Collet 30 and lead 4@ thus will be continuously rotated in a single predetermined direction while a line is being drawn. As -a result, the pencil point is `kept sharp for a longer .period of time and clean-cut lines of uniform thickness are attained.

Friction wheel assembly 70 may also be employed, if desired, to rotate lead 40 while the latter is being sharpened to obtain a sharp conical point.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the mean,- ing and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

l. In a mechanical pencil assembly adapted to hold an elongated piece of lead in surface engaging position, a manually grippable tubular casing, a forward pencil nose piece rotatably mounted at one end of said casing, lead holding means received in said nose piece and being rotatable therewith, said lead holding means being adapted to iixedly retain said piece of lead, a surface engaging wheel carried by said casing and mounted for rotation about an axis extending normal to the longitudinal axis of the casing, said means mounting said friction wheel comprising an arm carrying said wheel, means mounting said arm on said casing for rockable movement about a iixed pivot axis extending in parallel spaced apart relationship to the rotational axis of said wheel, means ior adjustably swinging said arm about said fixed `axis` to a fixed position, thereby permitting the linear distance between the periphery of the wheel and the forward end of the nose piece to be selectively varied, and drive mechanism connecting said nose piece to be driven from said wheel.

2. In a mechanical pencil assembly adapted to hold an elongated piece of lead in surface engaging position, a tubular manually grippable casing, means rotatably mounting a forward pencil nose piece in relatively fixed axial location on one end of said casing, lead holding means received in said nose piece and being rotatable therewith, said lead holding means being adapted to lixedly retain said piece of lead with its tip in marking position relative to a surface, a rotatable friction wheel carried by said casing with the lower periphery of said wheel being disposed adjacent the level of the tip of said lead for rolling along said surface or a parallel surface closely adjacent thereto, said wheel being rotatable about an axis transversely of the axis of said nose piece, and drive mechanism carried by said casing operatively connecting said nose piece to said wheel whereby` said lead is continuously rotated about its axis in marking relation to its associated surface as said Wheel is rolled along its associated surface.

3. In a mechanical pencil assembly adapted to hold an elongated piece of lead in surface engaging position, a tubular manually grippable casing, means rotatably mounting a Aforward pencil nose piece in axially fixed position on one end of said casing, lead holding means received in said nose piece and being rotatable therewith, said lead holding means being adapted to xedly retain said piece of lead, a carrier mounted on said casing and extending alongside said nose piece, a rotatable surface engaging friction wheel mounted on sai-d carrier, said wheel being rotatable about an axis transversely of the axis of said nose piece, and positive drive mechanism supported on. said carrier connecting saidl nose piece to said wheel whereby said lead is continuously rotated about its axis as said Wheel is rolled along :a surface.

4. In a mechanical pencil assembly adapted to hold an elongated piece of lead in surface engaging position, a tubular manually grippable casing, means rotatably mounting a forward pencil nose piece on one end of said casing, lead holding means received in said nose piece and being rotatable therewith, said lead holding means being adapted to fixedly retain said piece of lead, 1a carrier pivotally `adjustably mounted on said casing about a transverse axis, a rotatable surface engaging friction wheel carried by said carrier, said wheel being rotatable about an axis parallel to said adjustment axis and transversely of the axis of said nose piece, and drive mechanism connecting said nose piece to said wheel whereby said lead is continuously rotated about its axis as said Wheel is rolled along a surface, said drive mechanism comprising an element rotatable `about said adjustment axis whereby the angularity of said carrier may be varied without removing said arm from the assembly.

5. In a mechanical pencil assembly adapted to hold an elongated lpiece of lead in surface engaging position, a tubular manually grippable casing, means rotatably mounting a forward pencil nose piece on one end of said casing, lead holding means received in said nose piece and being rotatable therewith, said lead holding means being adapted to iixedly retain said piece of lead, a rotatable surface engaging friction wheel carried by said casing, said wheel being rotatable about an axis transversely of the axis of said nose piece, and drive mechanism connecting said nose piece to said wheel whereby said lead is continuously rotated about its axis as said wheel is rolled along a surface, said drive mechanism comprising a gear train having terminal gears respectively operatively connected to said nose piece and said friction wheel.

6. A mechanical pencil assembly comprising a tubular casing, a spindle rotatably mounted within said casing and having means adjacent one end adapted to receive and hold a piece of lead with one end of the lead projecting away from the casing in marking position, a member mounted on said casing, a friction wheel rotatably mounted on said member on an axis transversely of said spindle axis, drive transmission means between said wheel and said spindle, said member being pivoted on said casing for angular adjustment to vary the location of said wheel relative to said projecting end of the lead, and means for locking said member to said casing in different adjusted positions.

7. A mechanical pencil assembly comprising a tubular casing, a spindle rotatably mounted within said easing and having. means adjacent one end adapted to receive and hold a piece of leadr with one emi of the lead projecting away from the casing in marking position, a member detachaoly mounted on said casing, a friction Wheel rotatably mounted on said member on an axis transversely of said spindlev axis, drive transmission means between said wheel 'and said spindle, said means detachably mounting said member on said casing comprising a sleeve surrounding said Vcasing and releasably secured thereto, yand means pivotally adjustably mounting said member on saidsleeve.

References Cited by; the; Examiner UNTED STATES PATENTS4 Kowol 120-95 Johnson 1'20-15 Falconer 33-41 Graham 33-26 Consentino 120--89 Chelazzi 1Z0-22,

10 JEROME SCHNALL, Pimary Examiner.

LAWRENCE CHARLES, Examiner.

Claims (1)

1. 7. A MECHANICAL PENCIL ASSEMBLY COMPRISING A TUBULAR CASING, A SPINDLE ROTATABLY MOUNTED WITHIN SAID CASING AND HAVING MEANS ADJACENT ONE END ADAPTED TO RECEIVE AND HOLD A PIECE OF LEAD WITH ONE END OF THE LEAD PROJECTING AWAY FROM THE CASING IN MARKING POSITION, A MEMBER DETACHABLY MOUNTED ON SAID CASING, A FRICTION WHEEL ROTATABLY MOUNTED ON SAID MEMBER ON AN AXIS TRANSVERSELY

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