US3137275A

US3137275A - Mechanical pencil

Info

Publication number: US3137275A
Application number: US73102A
Authority: US
Inventors: Spatz Walter
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-12-01
Filing date: 1960-12-01
Publication date: 1964-06-16
Anticipated expiration: 1981-06-16

Description

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United States Patent() 3,137,275 MECHANICAL PENCL Walter Spatz, 11182 Sunset Blvd., Los Angeles 29, Calif. Filed Dec. 1, 1960, Ser. No. 73,102 4 Claims. (Cl. 1Z0-18) This invention relates to an improved mechanical pencil particularly for use either with lead or other writing or marking materials, such as crayons. The crayons may of course be larger in diameter and possibly of softer material. This invention provides a mechanical pencil which will propel the lead or crayon outwardly from the barrel of the pencil as desired; it will repel or retract the lead or crayon and nally will expel the end portion of the lead or crayon as it is used up. The invention particularly provides improved, efficient, effective and simplilied means for ejecting the lead or crayon when it is about to be used up, the ejecting member or stem coming substantially liush with the tip of the pencil when the lead or crayon is ejected.

A primary object of the invention is to provide an improved mechanical pencil as in the foregoing, the pencil particularly having the improved expelling or ejecting feature Vas described.

Another object is to provide an improved mechanical pencil as in the foregoing comprising relatively rotatable parts, longitudinally movable means operated by said parts for moving a lead carrier relative to the| pencil and means for moving the longitudinal means relatively to the lead carrier to provide flush ejection of lead or crayon or the like held by the leadcarrier.

A particular improvement of the pencil of this invention is that the barrel of the pencil may be made of plastic, the assembly comprising only four parts. The barrel may be made in one piece with bores and counterbores therein to accommodate the operating parts. There is a tubular rotatable member Within the barrel of the pencil, the end f which operates in a counterbore in the pencil. For ejecting the lead from the lead holder, it must of course move relatively tothe carrier or propelling and retracting stem. Ordinarily, in the prior art, this requires an undercut or shoulder in the barrel to prevent rotation of the lead holder during the ejection of the lead and operation of the propelling stem to a position properly spaced as respects the lead holder, that is to prevent rotation of the lead holder during relative axial movement of the lead holder and stem. This invention provides threaded engagement between the lead holder and the propelling stem in such operative relationship so that such undercut or shoulder in the barrel is not required making it unnecessary that this part of the pencil be made in two parts and making it possible to be made in one integral plastic part. The realization of this result is one of the objectives of the invention.

Another more specific object of the invention in relation to the foregoing is the provision of threaded engagement between the lead holder and the propelling and retracting stem in a mechanical pencil of the type described whereby the lead holder is normally propelled and retracte'd by the operating stem but relative axial movement is possible between them for expulsion of the lead without an undercut or shoulder means within the Vinterior of the pencil itself for restraining rotation of the pencil holder to effect the relative movement.

The manner of accomplishment of the foregoing obi jects will become more apparent from the detailed description.

' Further objects and numerous additional advantages of the invention will become apparent from the following detailed description and annexed drawings, wherein:

FIG. 1 is a view of a preferred form of the pencil of the invention;

ICC

' FIG. 2 is a sectional view of a part of the pencil;

FIG. 3 is a sectional view of the tip part of the pencil;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 2;

FIG. 5 is a perspective view of the longitudinally movable stem part of the assembly;

FIG. 6 is a perspective view of the end part of the cylindrical tube or barrel within the pencil;

FIG. 7 is a sectional perspective view of the lead holder; and

FIG. 8 is a section view of a lead holder of a modilied form of the invention.

Referring now more in detail to the various igures of the drawings, numeral 10 designates the exterior form of one embodiment of the invention. In this form of the invention, it comprises a barrel portion having a gently tapered end as shown at 11 and a part 12 of slightly smaller diameter, these parts being separated by the shoulder 13. This barrel part has a central bore 14 and another bore 15 of smaller diameter near the tip of the pencil, these bores being connected by the tapered bore or counterbore 16. The barrel has an additional bore 17 extending `towards the tip of the pencil from the bore 15 and providing a stop shoulder 15a therebetween, the bore 17 connecting by a short tapered counterbore 19 with a bore 20 of slightly smallery diameter in Ithe end of the barrel. See FIG. 3.

At the opposite end of the barrel part 11, it has a counterbore 23 and adjacent the end of this counterbore is an inwardly extending annular rib 25.

The cap or casing part of the pencil is designated by the numeral 27, it being cylindrical as shown and it may have a tapered end portion as shown at 26 in FIG. 1.

Within the casing 27 is a cylindrical or tubular member designated by the numeral 28. It has a part 29 at the end of larger diameter which fits snugly within the casing 27 to rotate therewith. It has a part 30 of slightly smaller diameter than part 29 which fits rotatably within the counterbore 23 of the barrel 11, there being an undercut or annular groove 31 between the parts 29 and 30 forming a square shoulder as shown. The rib 25 tits into the groove 31 and against the square shoulder at one side of the groove.

The tubular member 28 extends longitudinally within the bore 14 in the barrel 11 and it has an axial bore 34 as indicated in FIG. 4. The end part 35 of tubular member 2S is of smaller diameter as shown, there being a taper 36 between the parts of different diameter. j The tubular member 28 has an elongated axial slot as shown at 37 as may be seen in FIG. 6.

The bore 14 of the barrel 11 has formed therein a heli ical groove or internal helical thread as designated at 39 having the shape as shown in FIG. 2 preferably having a flat bottom and tapered side walls as shown in section in order to accommodate a longitudinally moving finger, projection or key member 41 as shown in FIG. 5. This key member is on the end of a rod, plunger or stem 42 having an extending part 43 of slightly smaller diameter. The numeral 44 designates the head of a small pin in the side of the part 43 of smaller diameter. The extending end of the key or linger 41 is coniigurated to accommodate itself to the cross-sectional shape of the helical groove 39.

3 and is of a size to fit into the bore 17 in the barrel 11. Its internal diameter is such as to receive a piece of lead or crayon. It has a radially extending projection, linger or key 52 which may alsomove longitudinally in the vslot 37. Within the end of the lead holder 50, it is provided with helical ribs forming a screw thread as designated at S4.

FIG. 2 shows the parts assembled with a piece of lead or crayon in the lead holder with the lead holder in its maximum position towards the tip of the pencil. FIG. 3 shows the tip in cross-section. If the cap or casing 27 is now rotated relative to the barrel part 11 (in one direction), by reason of the cooperation of the nger 41 with the helical thread 39, the key 41 will move longitudinally moving the rod or stern 42 with it. This will draw the lead holder Si) into the pencil into the broken line position shown in FIG. 2 with the key 52 moving in the elongated slot 37, because of the engagement of the pin 44 with the helical rib `or thread 54, which form an axial cam interconnection. If the cap or casing 27 and the barrel part 11 are rotated relatively in the opposite direction, the lead holder will move in the opposite direction for propelling the lead or crayon from the end or tip of the pencil. In other words, relative rotation the opposite way retracts or withdraws the lead. It will be understood of course that in the propelling and repelling or retracting of the lead, or crayon, the lead holder 50 rotates with the tubular part 28, the longitudinal movement of the plunger 42 being transmitted to the holder through the pin 44 and rib 54.

When the pencil has been operated to propel the lead or crayon to the `maximum extent,V that is to the position as shown in FIGS. 2 and 3, the key or projection 52 will be out of the slot 37 since the end part 35 of the tubular member 28 is spaced from the end of the bore 15 as may be seen in FIG. 2. The amount of this spacing is the length of the extending finger 46 which extends toward the shoulder at the end of bore from the end of tubular part 35. When the parts have reached the position shown in FIGS. 2 and 3, they are in a position ready for the lead or crayon to be expelled from the lead holder. At this time, the key 52 is against the stop shoulder 15a at the end of the counterbore 15, so that lead holder 50 cannot advance outwardly any further.

Continued rotation of the tubular member 2S relative to the barrel 11 in the same direction will cause the rod or stem 42 to continue to advance. The engagement of its pin 44 with the rib 54 will cause the lead holder SG to rotate relative to the stem 42 away from the linger 46 since the key 52 is not now in the slot 37. During such rotation, the end part 43 advances into the lead holder 50 and ejects or expels' the lead or crayon therein from the tip of the pencil. The extending pin head or button 44 on the stem 43 cooperates with the ribs or threads S4 inside the lead holder Si? so that these parts rotate relatively and allow part 43 to advance into the lead holder 50. That is, stem part 43 drives the lead holder 50 rotationally through a little less than a revolution. Now upon relative rotation of barrel 11 and part 2S in the opposite direction, stem part 43, by virtue of engagement of the pin 44 with the rib 54 and because of engagement of the holder projection 52 with the forward end of the tubular member 28, rotationally drives lead holder 50 until key 52 picks up linger 46 at slot 37 at which time the lead holder projection 52reshifts into the slot 37 and retracts in the vtubular member 28 with the stem 42, that is, part 43 moves back axially in the lead holder before retracting it.

FIG. 8 shows the lead holder 51' having relatively thicker side walls as indicated at S7 and a counterbore 58 in the end of larger diameter than the bore 59 having the ribs 54 in it. This lead holder may be used in place of the one of the other figures for utilizing a crayon or marking member of larger diameter.

From the foregoing, those skilled in the art will observe that the invention as described herein achieves and realizes the objectives set forth in the foregoing. It provides a mechanical pencil constructed of a small number of simplified, rugged and effective parts. Particularly, the invention provides for simplified and effective means for ejecting the lead or crayon whichever is used when it is about to be used up. This is done in an effective and convenient manner after which the parts operate to enable the insertion of a new length of lead or crayon. The propelling stem advances and retracts relative to the lead holder for expelling the lead without there being an undercut or shoulder within the barrel to serve as a rotational stop for the lead holder. Thus, the barrel can be made inexpensively and easily as a one-piece integral unit.

|The foregoing disclosure is representative of a preferred form of the invention and is to be interpreted in an illustrative rather than a limiting sense, the invention to be accorded the full scope of the claims appended thereto.

What is claimed is: i v

l. In a mechanical pencil: a barrel having an internal helical thread; a tubular member within said barrel hav- `ing a longitudinal slot; said barrel and tubular member being relatively rotatable; a pencil holder in said barrel slidable in said tubular member and having a projection movable in said slot free from engagement with said thread, said projection being movable from said slot at the forward portion of said tubular member; a plunger slidable in said tubular member rearwardly of said holder and having a projection extending through said slot into meshing engagement with said thread; means providing an axial cam interconnection between said plunger and holder that causes longitudinal movement of said holder with said plunger upon relative rotation of said barrel and tubular member with both of said projections in said slot and which is adapted torelatively rotate said plunger and holder upon relative longitudinal movement therebetween; means engageable with said holder to limit its forward movement in said barrel with its projection free from said slot, whereby relative rotation of said barrel and tubular member in one direction advances said plunger into said holder to simultaneously rotate said holder and expel a pencil therefrom; and means engageable with said holder after its forward movement has been limited and it has been rotated by said plunger to initially prevent rearward movement of said holder in said barrel, whereby relative rotation of said barrel and tubular member in the opposite direction simultaneously retracts said plunger in said holder and causes said axial cam interconnection to rotate said holder to place its projection in alignment with said slot and in position for reentry thereinto.

2. In a mechanical pencil: a barrel having an internal helical thread; a tubular member within said barrel having a longitudinal slot; said barrel and tubular member being relatively rotatable; a pencil holder in said barrel slidable in said tubular member and having a projection movable in-'said slot free from engagement with said thread, said projection being movable from said slot at the forward portion of said tubular member; a plunger slidable in said tubular member'rearwardly of said holder and having a projection extending through said slot into meshing engagement with said thread; means providing an axial cam interconnection between said plunger and holder that causes longitudinal movement of said holder with said plunger upon relative rotation of said barrel and tubular member with both of said projections in said slot and which is adapted to relatively rotate said plunger and holder upon relative longitudinal movement therebetween; said barrel having a stop shoulder at its forward portion engageable by said holder projection to limit forward movement of said holder in said barrel with its projection free from said slot, whereby relative rotation of said barrel and tubular member in one direction advances said plunger into said holder to simultaneously rotate said holder and expel a pencil therefrom; said tubular member providing stop means at its for ward portion engageable with said holder projection after forward movement of said holder has been limited and said holder has been rotated by said plunger to initially prevent rearward movement of said holder in said barrel, whereby relative rotation of said barrel and tubular member in the opposite direction simultaneously retracts `said plunger in said holder and causes said axial cam interconnection to rotate said holder to place its projection in alignment with said slot and in position for reentry thereinto. t y

3. In a mechanical pencil: a barrel having an internal helical thread; a tubular member within said barrel having a longitudinal slot; said barrel and tubular member being relatively rotatable; a pencil holder in said barrel slidable in said tubular member'and having a projection movable in said slot free from engagement with saidl ing means engaging said rib to relatively rotate saidr plunger and holder upon relative longitudinal movement therebetween; means engageable with said holder to limit its forward movement in said barrel with its projection free from said slot, whereby relative rotation of Vsaid barrel and tubular member in one direction advances said plunger into said holder to simultaneously rotate said holder and expel a penciltherefrom; and means engage-A able with `said holder after its forward movement has been limited and it has been rotated by said plunger to initially prevent rearward movement of said holder in said barrel, whereby relative rotation of said barrel and tubular member in the opposite direction simultaneously retracts said plunger'in said holder and causes said helical rib and actuating means to rotate said holder to place its projection in alignment with said slot and in position for reentry thereinto. Y

4. In a mechanical pencil: a barrel having an internal helical thread; a tubular member within said barrel having a longitudinal slot; said barrel and tubular member being relatively rotatable; a pencil holder in said barrel slidable in said tubular member and having a projection movable in said slot free from engagement with said thread, said projection being movable from said slot at the forward portion of said tubular member; a plunger slidable Y tuating means engaging said rib to relatively rotate said plunger and holder upon relative longitudinal movement therebetween; said barrel having a stop shoulder at its forward portion engageable by said holder projection to limit forward movement of said holder in said barrel with its projection free from said slot, whereby relative rotationof said barrel and tubular member in one direction advances said plunger into said holder to simultaneously rotate said holder and expel a pencil therefrom; said tubular member providing stop means at its forward portion engageable with said holder projection after forward movement of said holder has been limited and said holder has been rotated by said plunger to initially prevent rearward movement of said holder in said barrel, whereby relative rotation of said barrel and tubular member in the opposite direction simultaneously retracts said plunger in said holder and causes said helical rib and actuating means to rotate said holder to place its projection in alignment with said slot and in position for reentry thereinto.

References Cited in the ile of this patent UNITED STATES PATENTS Aversa Nov. 8, 1955

Claims

1. IN A MECHANICAL PENCIL: A BARREL HAVING AN INTERNAL HELICAL THREAD: A TUBULAR MEMBER WITHIN SAID BARREL HAVING A LONGITUDINAL SLOT; SAID BARREL AND TUBULAR MEMBER BEING RELATIVELY ROTATABLE; A PENCIL HOLDER IN SAID BARREL SLIDABLE IN SAID TUBULAR MEMBER AND HAVING A PROJECTION MOVABLE IN SAID SLOT FREE FROM ENGAGEMENT WITH SAID THREAD, SAID PROJECTION BEING MOVABLE FROM SAID SLOT AT THE FORWARD PORTION OF SAID TUBULAR MEMBER; A PLUNGER SLIDABLE IN SAID TUBULAR MEMBER REARWARDLY OF SAID HOLDER AND HAVING A PROJECTION EXTENDING THROUGH SAID SLOT INTO MESHING ENGAGEMENT WITH SAID THREAD; MEANS PROVIDING AN AXIAL CAM INTERCONNECTION BETWEEN SAID PLUNGER AND HOLDER THAT CAUSES LONGITUDINAL MOVEMENT OF SAID HOLDER WITH SAID PLUNGER UPON RELATIVE ROTATION OF SAID BARREL AND TUBULAR MEMBER WITH BOTH OF SAID PROJECTIONS IN SAID SLOT AND WHICH IS ADAPTED TO RELATIVELY ROTATE SAID PLUNGER AND HOLDER UPON RELATIVE LONGITUDINAL MOVEMENT THEREBETWEEN; MEANS ENGAGEABLE WITH SAID HOLDER TO LIMIT ITS FORWARD MOVEMENT IN SAID BARREL WITH ITS PROJECTION FREE FROM SAID LSOT, WHEREBY RELATIVE ROTATION OF SAID BARREL AND TUBULAR MEMBER IN ONE DIRECTION ADVANCES SAID PLUNGER INTO SAID HOLDER SIMULTANEOUSLY ROTATE SAID HOLDER AND EXPEL A PENCIL THEREFROM; AND MEANS ENGAGEABLE WITH SAID HOLDER AFTER ITS FORWARD MOVEMENT HAS BEEN LIMITED AND IT HAS BEEN ROTATED BY SAID PLUNGER TO INITIALLY PREVENT REARWARD MOVEMENT OF SAID HOLDER IN SAID BARREL, WHEREBY RELATIVE ROTATION OF SAID BARREL AND TUBULAR MEMBER IN THE OPPOSITE DIRECTION SIMULTANEOUSLY RETRACTS SAID PLUNGER IN SAID HOLDER AND CAUSES SAID AXIAL CAM INTERCONNECTION TO ROTATE SAID HOLDER TO PLACE ITS PROJECTION IN ALIGNMENT WITH SAID SLOT AND IN POSITION FOR REENTRY THEREINTO.