US2365548A

US2365548A - Mechanical pencil

Info

Publication number: US2365548A
Application number: US418874A
Authority: US
Inventors: Paul S Hauton
Original assignee: SCRIPTO Manufacturing Co
Current assignee: SCRIPTO Manufacturing Co
Priority date: 1941-11-13
Filing date: 1941-11-13
Publication date: 1944-12-19
Anticipated expiration: 1961-12-19

Description

, 1944. P. s. HAUTON MECHANICAL PENCIL Filed Nov. 15, 1941 2 Sheets-Sheet 1 m T N E V m P. S. HAUTON MECHANICAL PENCIL Filed NOV. 13, 1941 Dec. 19, 1944.

2 Sheets-Sheet 2 KNVENTOR PAUL s HATQN Patented Dec. 19, 1944 macnamcar. PENCIL Paul S. Hauton, Atlanta, Ga., assignor to Scripto Manufacturing Company, Atlanta, Ga., a cornotation of Georgia Application November 13,1941, Serial No. 418,874

* 12 Claims.

This invention relates to mechanical pencils and has more particular reference to screw operated mechanical pencils having chambers for storing reserve leads.

This application is a continuation in part of the application of Paul S. Hauton, Serial No. 259,535.

One of the objects of the invention is to minimize the possibility of clogging the leadmoving mechanism by broken lead or other extraneous objects.

Another object of the invention is to provide a. simplified arrangement for confining the spare leads to reserve storage spaces or chambers and to render the storag space accessible when desired.

Another object of the invention is to render visible certain parts of the lead moving mechanism while concealing some of the other parts.

Another object of the invention is to provide a simplified arrangement of lead grip sleeve and ejector to minimize possible damage to the parts.

Other and further objects will be pointed out or will become apparent to one skilled in the art as the description proceeds.

comprehensively stated, the invention comprises feed mechanism including a shielded screw member, the shielding serving, together with mechanism closing off the end of the lead reserve chamber, to confine the spare leads to the reserve chambers which in the preferred. embodinmt are molded in forming the barrel or housing so as to communicate with some of its longitudinal bores and thereby prevent lead from entering and interfering with the normal operation of the lead feeding mechanism, the shielding also serving to partly conceal some of the lead feeding mechanism and leaving some of the lead feeding parts visible through at least a part of the barrel, when the barrel as shown in its preferred form is formed of transparent or translucent moldable material.

More specifically stated, the invention comprises a pair of slotted tubes, onopposite sides of a helix, the slots permitting the lugs of the ejector mechanism and lead grip sleeve mechanism to engage a longitudinal slot in the molded barrel, the tube surrounding the helix serving as a partition between the helix and the chambers for reserve leads and partly concealing the operating mechanism when the barrel or casing is formed of transparent or translucent material and means for indicating the position of the lead grip sleev visible at least through a part of the transparent or translucent barrel in the region of the back and forth movement of the indicating means. The end of the seam of the seamed tubular lead grip sleeve adjacent to the lead ejecting mechanism is offset from the lug of the lead ejector pin so as to avoid opening the tubular lead grip sleeve along its seam when the ejector mechanism strikes'the end of the lead grip sleeve. The reserve leads are further confined to their chambers by a door or gate arrangement affording access to some of the reserve lead chambers and rotatable so as to afford access to other reserve lead chambers in the event that reserve lead chambers on the opposite side of the pencil are used as is contemplated.

The invention comprises various combinations and sub-combmations of the invention generally and specifically outlined.

While one embodiment of this invention is illustrated in the accompanying drawings, it is to be understood that such embodiment merely serves as an illustration of th underlying principles of the invention so that it may be readily comprehended by those skilled in the art, and is not intended as limiting the invention to the specific details disclosed therein.

In said drawings:

Fig. 1 is a side elevation of the assembled pencil, including a transparent or translucent barrel.

Fig. 2 is a side elevation of the inventionpartly sectioned and partly fragmentary.

Fig. 3 is a section of Fig. 1 on the line 33.

Fig. 4 is a. section of Fig. 9,011 the line 4-4.

Fig. 5 is an end elevation of one of the lead moving parts.

Fig. 6 is a fragmentary side elevation of the lead moving part shown in Fig. 5.

Fig. 7 is a section in part of the pencil shown in Fig. 2, rotated Fig. 8 is an end elevation of the pencil parts at the eraser end of the pencil with the eraser ferrule and its eraser removed.

Fig. 9 is a side elevation of the parts shown in Fig. 8 with the eraser ferrule and its eraser removed.

Fig. 10 is a side elevation of the lead grip sleeve and ejector pin partly fragmentary.

Fig. 11 is a side elevation of the elements shown in Fig. 10, also partly fragmentary.

Fig. 12 is a section of Fig. 11 on the line lZ-IZ, and

Fig. 13 is an end elevation of a modified form of the arrangement shown in Fig. 8.

end with a preferably rigid lead guide tip B. The barrel has a longitudinal axial bore B to re ceive the lead moving mechanism with a pinof the pencil barrel A from which end access to the lead reserves is obtained as will be more fully described hereinafter. The barrel A which houses the lead moving mechanism preferably consists of a transparent or translucent material so that the position of some of the lead moving parts can be readily determined by visual inspection particularly when the arrangement which will be described more fully hereinafter is used with this type of barrel material.

The lead moving mechanism includes an open threaded helix D formed by coiling a flat strip of material to requisite shape, the helix terminat ing in a stub end D for facilitating pick up of the lead grip sleeve, with a seamed tubular lead grip sleeve E and an ejector pin F longitudinally slidable therein, the lead grip sleeve having a helix engaging lug G and the ejector pin having a helix engaging lug H, both lugs passing through the turns of the open threaded helix D and constrained to move longitudinally of the barrel by sliding in a longitudinal slot J formed contiguous to the bore in the barrel A. On rotation of the helix relatively to the barrel, both lugs move longitudinally of the barrel maintaining their spacing so that the ejector is in retracted position with respect to the lead grip sleeve. When the lead grip sleeve reaches the end of its stroke at the writing end on the pencil its lug disengages from the helix D. On continued rotation of the helix in lead advancing direction the ejector pin lug advances and elects the lead from the lead grip sleeve. In order to divide the spare lead receiving chambers C and C from the helix and to simultaneously conceal most of the helix without interfering with the travel of the lead grip sleeve lugs G and H in the longitudinal slot J, a sleeve K having a narrow longitudinal slot or slit L surrounds with a loose running fit the helix D, the slot L registering with the longitudinal lug guide slot J to permit the lugs G and H to engage said longitudinal slot and to be moved back and forth in the pencil as the helix is rotated. In order to avoid short pieces of lead from working into the operating mechanism from the inside of the helix D and to insure proper alignment of short pieces of lead so that on the forward stroke the lead will properly enter the bore of tip B a similar shielding sleeve M having a. longitudinal slit or slot N has a loose running fit against the inside of the helix D, the slot N permitting the lugG of the lead grip sleeve and the lug H of the ejector pin to ride therein. From the foregoing description it will be seen that the helix D is shielded both on the inside and on the outside, each sleeve having longitudinal slits in registry with each other and with the slot J which permits the lugs to move longitudinally back and forth when the helix D is rotated. The sleeve K is anchored to the barrel A by 8. lug K engaging a slot K" at the eraser end of the barrel. In

order that the maximum shielding of the helix sleeves are comparatively narrow and so that the lugs G and it may travel freely in this narrow slit, the necks of lugs G and H are narrowed at P and Q respectively. To permit "free riding of the lugs G and H without damage to the walls of the slot J, the lugs have embossed or smooth- 1y raised sections B. These sections may be formed in any convenient manner as for instance by striking out the wall ot-the lugs G and utilizing the cylindrical shape of the ejector pin lug F as will be readily understood. The lead grip sleeve E is shaped from a blank into cylindrical iorm having a. seam and in order to prevent the lug H of the ejector pin 1 which is in alignment with the lead grip sleeve lug G from striking the meeting edges of scam S of the lead grip sleeve, the meeting edges of seam S are ofiset at the end of the lead grip sleeve adjacent the elector pin lug so that the meeting edges of the seem at this point are not in line with the ejectdr pin lug and the lead grip sleeve lug. This ofisetting of the end ofthe seam meeting edges is effected by suitably cutting the lead grip sleeve blank as will be readily understood so that one end or the seam is angularly disposed with respect to the seam in the region 01' the lead grip sleeve lugs. The lead grip sleeve lug G is formed by cutting two opposite ears in the blank prior to forming the tubular lead grip sleeve. The abutting ears forming the'lead grip sleeve lug are aligned with the ejector pin lug in the pencil. As heretofore stated the ejector pin F moves relatively to the lead grip sleeve E when the lead grip sleeve lug G is arrested by striking the lower end of the slot J. If the rotation of the helix is continued the ejector pin lug H moves toward the lug G after the latter is arrested until the lug H strikes the top of the lead grip sleeve E which is not seamed at the striking point and danger of opening and distortion is avoided. The slot J is of suflicient length so that the lead grip sleeve lug at the forward end of its stroke clears the may be eifected the slits in the shielding 1c in helix D. In order to insure proper pick-up of the ejector lug G by the retractile movement of the ejector pin, the ejector pin is slotted at T to provide a shoulder T' adapted to engage the nose of the member U formed upon the lead grip sleeve E so that the lead grip sleeve will of necessity accompany the ejector pin at the proper time and will enter the helix facilitated by the specially shaped and D' of the last helix turn.

The cam shaped and D of the last helix turn also permits the use of the longest possible movement of the ejector pin F in the lead carrier H. In case lug G should try to enter the helix because the lugs happen to be at minimum spacing, the cam shaped end D will push the lug away so that it will enter on the next turn of the helix when the lugs will be at maximum spacing. The general arrangement of lead carrier E and elector pin F are the same as described in my Patent No. 2,265,162, except that in the present invention both lugs travel in the same guide slot or channel.

As is well understood the.rotation of helix D moves the lugs G and H back and forth depending on the direction of itsirotation. In order to positively rotate the helix a driving cap V is locked to the helix D by providing an opening W in the helix engaged by 9. lug W suitably formed in the driving cap V. A cylindrical eraser ferrule X rides on the periphery of the cylindrical reduced end X formed at the eraser end of barrel A and is in frictional engagement with the dependent skirt of the driving cap V which rides a further reduced end or the casing A at the accuse eraser end of the pencil. In order that the driving cap maybe rotatably held on the barrel A the driving cap has a detent engaging an annular groove V' formed in the casing near its eraser end. 1

To provide convenient access to the lead reserve chambers C and C and to close off the ends of the spare lead receiving chambers independently of the eraser ferrule, a semi-circular tiltable gate or door Y is pivoted at Y in bearings conveniently formed with the driving sleeve V so that the free end of the gate may be swung up to expose the open ends of the spare lead receiving chambers when access to the chambers is desired and the eraser ferrule is removed. This gate or door is locked in closed position by the spring latch Z having a cam nose adapted to engage the door and formed with or secured to the driving can by a curved cam nose suppor arm. The gate serves to cover an opening in the driving sleeve adapted to register with the open end of one of the spare lead chambers at one side of the barrel, the spare lead chambers on the other side of the barrel being closed off by the extended portion or covering wings Z" of a lug carried by the driving cap V and locking with one end of the helix D. Since the gate is pivoted in diametrically opposite bearings extending upwardly from the driving cap V, the gate Y will rotate about the axis of the pencil simultaneously with the helix engaging lug and its win-gs Z" covering the diametrically opposite lead reserve chambers. If it is desired to obtain access to the lead reserve chambers the ends of which are closed off by the helix engaging lug wings Z", the driving cap may be rotated so that the gate Y is positioned over the lead reserve chambers previously closed off by the extended portions or wings of the helix engaging lug, the latter extended portions thereupon closing off the lead reserve chambers previously accessible by lifting the gate Y. In order to prevent accidental opening of the gate Y while the eraser ferrule is in place the end of the gate Y has a dependent ferrule interlocking lug Z at it free end forming a sufliciently wide ferrule abutting face so that the door cannot rotate about its pivot points until the ferrule is removed.

A marker element I4 preferably of contrasting color to facilitate determination of the working length of the pencil lead is slipped between lugs G and H and is short enough so as not to interfere with the operation of the ejector pin lug. This marker element is preferably slidable in the slot J but will normally take an abutting position against the lug G when the pencil is held in writing position.

In the alternative arrangement for closing off the open ends of the spare lead reserve chambers shown in Fig. 13 a cover plate or gate Y is pivoted at Y to cover the open ends of the chamber C and on rotation of the hinge Y with the driving cap V to take a position closing oil the open ends of the spare lead reserve chambers C in a manner similar to that shown in Fig. 8 and described in connection therewith. The cover plate or gate Y instead of rotating about an axis at right angles to the longitudinal axis of the pencil as shown in Fig. 8, in the alternative form shown in Fig. 13 rotates about an axis parallel to the longitudinal axis of the pencil.

It will be noted that the arrangement of obtaining access to the reserve lead chambers permits drive of the pencil while at the same time affording easy access to the reserve leads.

The

helix is partly surrounded by a comparatively -thin tubular member having an opening along helix is similarly shielded by a similar thin tubular member which has its-lower end seated in a restricted portion of the barrel bore so as to form a continuous opening communicating with the opening in the lead guide tip.

Referring more particularly to Fig. 7 the pencil has a pocket clip Ill locked to the pencil by lugs H and I! which is more particularly the subject matter of a co-pending application of Paul S. Hauton, Serial No. 353,324.

' When I speak in my claims of having atransparent portion, I mean to include a transparent, translucentor a portion of the barrel cut away so as to render visible some of the operating mechanism.

It is claimed:

1. A mechanical pencil combining a barrel having a longitudinal bore and lug guide slot, a lead reserve chamber, the bore communicating with the slot and lead reserve chamber, a lead grip sleeve having a lug, a rotatable helix in the bore, a driving cap rotatably secured to one end of the barrel, a tube having a slot surrounding the helix, the lead grip sleeve lug riding in the slot and engaging the helix turns, the slotted tube closing off one side of the lead reserve chamber, and means carried by the driving cap for closing off the open end of the lead reserve chamber.

2. A lead grip sleeve for mechanical pencils having a projecting lug with raised sections on the side of the lug and spaced from the lead grip sleeve to form a restricted neck and enlarged slot engaging end.

3. In a pencil the combination of a casing having a center bore with a longitudinal extending channel, lead moving mechanism in the center bore including a helix, a lead carrier having a lug engaging the helix and the longitudinal channel and a thin wall slotted tube between the lead carrier and the helix to prevent small pieces of lead from getting into the helix.

4. Mechanical pencil comprising a barrel havin a longitudinal bore and a longitudinal slot opening in said bore, a helix with spaced turns mounted in said bore, means for rotating said helix relative to said barrel, a lead grip sleeve and an ejector pin within said helix, said pin being slidable within said sleeve, said sleeve and pin having lateral lugs in longitudinal spaced relation extending between turns of said helix and into said slot, whereby turning of said helix produces longitudinal movement of said lugs in said slot, and a lead length indicator slidable in said slot, positioned between said lugs.

5. Mechanical pencil comprising a barrel having a longitudinal bore and a longitudinal slot opening in said bore, a helix with spaced turns mounted in said bore, means for rotating said helix relative to said barrel, a lead grip sleeve and an ejector pin within said helix, said pin being slidable within said sleeve, said sleeve and pin having lateral lugs in longitudinal spaced relation extending between turns of said helix and into said slot, whereby turning of said helix produces longitudinal movement of said lugs in said slot, and a lead length indicator slidable in said slot, positioned between said lugs, said barrel being transparent at least in the region overlying the path of travel of said indicator.

6. Mechanical pencil comprising a barrel having a longitudinal bore and a longitudinal slot opening in said bore, a helix with spaced turns mounted in said bore, means tor rotating said helix relative to said barrel, a lead grip sleeve and an elector pin within said helix, said pin being slidable within said sleeve, said sleeve and pin having lateral lugs in longitudinal spaced relation extending between turns of said helix and into said slot, whereby turning of said helix produces longitudinal movement of said lugs in said slot, said barrel being provided with means forming a limit stop for the pointwise movement 01 said lead grip sleeve 1118, positioned below said helix, whereby rotation of said helix subsequent to the stopping of said lead grip sleeve lug moves said ejector pin relative to said lead grip sleeve, and a lead length indicator slidable in said slot, positioned between said, lugs.

' 7. In a mechanical pencil, a, barrel having a bore and a longitudinal slot opening in said bore, a helix with spaced turns in said bore rotatable relative to said barrel, longitudinally slotted tubes, one surrounding and the other surrounded by said helix having their slots in alignment with the barrel slot, and a lead carrier reciprocable within said helix having a lateral lug extending through the slots of said tubes, the space between the turns of said helix and into said barrel slot.

8. Mechanical pencil comprising a barrel, means for moving the writing lead including a rotatable helix having spaced turns, a longitudinally movable lead carrier within said helix and having a. lug engaging the helix turns, and tubes located on the outside and inside of the helix having longitudinal slots also engaged by said lug.

9. Mechanical pencil comprising a barrel having a longitudinal bore, a longitudinal guide slot within said bore, a helix with spaced turns mounted in said bore, a lead grip sleeve and ejector pin within said helix, said pin being slidable within said sleeve, sad sleeve and pin having lateral lugs in changeable, longitudinal spaced relation and extending between turns of said helix and into said guide slot so that turning of said helix produces longitudinal movement of said lugs in said guide slot, means for stopping the pointwise movement of said sleeve after said sleeve lug disengages from said helix so that rotation of said helix subsequent to the stopping of said sleeve lug causes movement of the ejector pin lug from the maximum to the minimum spaced relation of said lugs, said lead grip sleeve and ejector pin having cooperating stop means carried solely by said lead grip sleeve and elector pin for establishing the maximum longitudinal spacing of said lugs at a distance equal to complete turns, at least two in number, of said helix and the minimum longitudinal spacing of said lugs at the shortest distance which permits restoring of said lugs to maximum longitudinal spacing by reverse rotation of said helix before said disengaged lug reenters said helix.

10. it lead cag and electing mecm for mechanical pencils, comprising a rotatable helix with spaced turns, a lead grip sleeve and ejector pin within said helix, said pin being slid= able in said sleeve said sleeve and pin having lateral lugs in changeable, longitudinal spaced relation and normally extending between complete turns, at least two in number, of said helix when both lugs are engaged by said helix, a longitudinal slot for guiding said lugs, said slot extending below said helix to permit disengagement of said lead grip sleeve lug from said helix and cooperating stops on said sleeve and pin for establishing the normal and the minimum longitudinal spacing of said lugs, the minimum spacing being the shortest distance between said lugs when the sleeve lug is disengaged from said helix which permits said helix to prevent entrainment of said diseng ed lug upon resetting movement of said helix when said lugs are not in normal spaced relation.

11. Mechanical rpencil comprising a barrel, a helix mounted in said barrel having spaced turns defining a helical slot, means for rotating said helix relative to said barrel, a. longitudinal guide slot within said barrel, a lead grip sleeve and ejector. pin within said helix, said pin being slidable within said sleeve, said sleeve and pin having lateral lugs in changeable longitudinal spaced relation and extending into said longitudinal uide slot between the turns of said helix so that rotation of the helix produces longitudinal movement of said lugs in said guide slot, said guide slot extending below said helix permitting disengagement oi said lead grip sleeve lug from said helix, the last turn of said helix terminating in a downwardly and rearwardly inclined face, referred to the resetting direction of movement of said helix, extending from said helical slot to the bottom of said helix forming a cam engageable with said lead grip sleeve lug for rejecting said lug until said lugs are in their relative position or maximum spacing.

12. Mechanical pencil comprising a barrel having a longitudinal bore and a longitudinal slot opening into said bore, a helix with spaced turns mounted in said bore, means for rotating. said