US2496554A

US2496554A - Mechanical pencil

Info

Publication number: US2496554A
Application number: US716907A
Authority: US
Inventors: Lynn Gary
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-12-18
Filing date: 1946-12-18
Publication date: 1950-02-07
Anticipated expiration: 1967-02-07

Description

y Feb. 7 1950 G. LYNN 2,496,554

MECHANICAL PENCIL Filed Deo. 18, 1946 2 Sheets-Sheet l Feb. 7, 1950 G. LYNN 2,496,554

MECHANICAL PENCIL Filed Dec. 18,4 1946 2 Sheets-Sheet 2 11 \/57 )SiC-4 MQW/WW II////v Patented Fel). 7, 1950 UNITED `STATES PATENT OFFICE MECHANICAL PENCIL Gary Lynn, Melrose Park, Ill.

Application December 18, 1946, Serial No. 716,907

(Cl. 1Z0- 18) 6 Claims. l

This invention relates to mechanical pencils and is more particularly concerned with the provision of a pencil embodying means for guiding and feeding relatively large diameter lead suitable for such uses as marking packages, checking items, marking bowling scores, et cetera. In marking bowling scores, printing on packages, et cetera, it has heretofore been the practice to use crayons which, due to their enlarged diameters, must be provided with a sharpened point in order to provide legible writing or printing. Crayons are also objectionable as they become softened and broken through use in hot weather.

The present invention contemplates the provision of a mechanical pencil embodying either a screw feed mechanism or a reciprocable clutch feed mechanism for progressively moving a relatively large diameter lead toward the point of the pencil.

This invention further contemplates the provision of a mechanical pencil embodying a feed mechanism adapted to be enclosed within a twopiece housing which, in turn, is inserted into and frictionally engaged within the barrel or body of the pencil.

This invention further contemplates the provision of means for preventing relative longitudinal movement of the two pieces of the split housing during or after assembly of same within the barrel of a pencil.

This invention embodies other novel features, details of construction and arrangement of parts which are hereinafter set forth in the specication and claims and illustrated in the accompanying drawings wherein:

Fig. 1 is a longitudinal sectional view showing a mechanical pencil embodying features of this invention.

Fig. 2 is a transverse sectional View taken along the line 2--2 of Fig. 1.

Fig. 3 is a transverse sectional View taken along the line 3-3 of Fig. 1.

Fig. 4 is a longitudinal sectional view showing a modified form of a checking pencil embodying features of this invention.

Fig. 5 is a transverse sectional View taken along the line 5-5 of Fig. 4.

Fig. 6 is a transverse sectional View taken along the line 6-6 of Fig. 4.

Referring now to the drawings for a better understanding of this invention and more particularly to Figs. 1, 2 and 3 therein, the mechanical pencil is shown as comprising a lead guide tube 1 adapted to receive a relatively large diameter lead 8. The lead guide tube I is preferably 2 blanked and formed of relatively thin sheet metal to provide a longitudinally extending slot 9 and a neck portion il of reduced diameter to frictionally engage the lead 8.

A feed plug I2 is mounted for reciprocable movement within the lead guide tube i for moving the lead il outwardly through the reduced neck portion II. The feed plug I2 is provided with a feed shoulder I3 which projects outwardly through the longitudinally extending slot 9 for engagement within a helical groove Iii formed in a feed housing I6. In order to prevent breakage of parts, the helical groove lil terminates at its ends in run-out chambers Il and E8 which permit rotational movement of the feed housing I6 without imparting reciprocatory movement to the feed plug i2. The feed housing Iii is also split longitudinally along diametrically opposed sides, as illustrated in Figs` 2 and 3, to facilitate assembly and to reduce the cost of manufacture. By making the feed housing in two halves, each section Ilia and It?) may be inexpensively formed by either die casting or stamping operations. The sections ISa and Itb of the feed housing It are secured in proper alignment by means of a head plug I9 formed with an annual flange 2l to be received in arcuate aligning recesses 32e-22. The inner end of the head plug I9 is formed with a cylindrical boss 23 for insertion into the inner end of the guide tube `I. The guide tube 'I is secured to the cylindrical boss 23 by welding -or brazing to form a relatively strong, rigid unitary structure adapted to be rotated within the split feed housing I6.

A barrel 25 formed of plastic, metal or other suitable material is provided to snugly and frictionally receive and engage the split feed housing I6. The outer end of the barrel 2S is reduced at 2l and formed with a reduced bore at 2s to receive the neck portion I I of the guide tube An aperture 29 is formed in the outer end of the barrel 26 for the passage of the lead t.

If desired, a ring portion 3l of a clip 32 may be mounted on the split feed housing iii between the head portion 33 thereof and the inner end of the barrel 26. A band of thin metal sli is mounted over the inner end of the split feed housing it to enclose the ring portion 3l of the clip 32. A suitable cap 36 formed of plastic or metal is pressed over the head plug I9 and is secured against relative rotational or axial movement therewith by means of a knurled surface 3'! formed on the plug I9. A helical compression spring 3S is mounted within the cylindrical boss 23 to urge the feed plug I2 outwardly to move the feed shoulder I3 3 out of the run-out chamber il and into the helical groove I4. If desired, a tassie may be inserted through an opening 42 formed in the end of the cap 36 for threaded engagement at 43 in the head plug I9, in which event the clip 32 would be omitted from the pencil construction.

In the use of a pencil of the type shown and described, the lead 8 is forced outwardly through the guide tube l by means of relative rotational movement between the guide tube 'i and the split feed housing iii. When the feed plug l2 is in its inner position, as indicated in Fig. l, the compression spring 38 acts to move the feed plug i2 outwardly until the feed shoulder I3 moves into the helical groove Iii. When the feed shoulder i3 is disposed within the helical groove it will be noted that relative movement between the guide tube l and the split leed housing IG will cause reciprocable movement of the feed plug l2. As

the lead 8 becomes worn, the feed plug l2 will eventually come to rest at the outer end of the guide tube l, with the feed shoulder i3 disposed within the run-out chamber i8. in refilling the pencil with a new lead, the feed plug is moved to its inner position, illustrated in Fig, l, and a. lead 8 is inserted into the guide tube l.

Figs. 4, and 6 illustrate a modified .form of this invention in which the pencil is shown as comprising a guide tube 5S to receive lead 32.

The guide tube 5! is enclosed within a split feed 0 housing 53 formed of two similar hal; sections 53a and 53h. Each section 53( ...id i533: provided with an arcuate recess Sil to receive annular flange 56 formed on the inner end of a friction collar El. The annular iange SLS serves to hold the sections and 53h in alignment with each other. The sectie ormng the feed housing 53 are snugly receA -ed frictionally engaged within a barrel ES formed of plastic or metal.

A plurality of tapered fingers 59 are ffrmed on the outer end of the guide tube 5i for engagement by an annular clutch collar 6i which acts to move the lingers 59 into clutching engagement against the lead 52 when thc guide tube 5l is moved inwardly to its position shown in Fig. The guide tube 5l is normally urged to its inner position by means of a helical compression spring interposed between a shoulder E3 formed on the guide tube 5l and a bearing Eli formed on the split feed housing 53. During inward movement of the guide tube 5l, it is brought to rest by engagement of the shoulder against bearing G5 formed on the feed housing A. si. table cap 6l is secured to the end of the guide tube 5l for engagement by the thumb of the user in reciprocating the guide tube to impart a step-by-step outward movement of tfie lead During forward movement of the guide tube 5i the fingers 59 are held in tight engagement against the lead 52 by means of the clutch collar E l. As the guide tube approaches the forward end of its stroke, the clutch collar 6| is brought to rest against a shoulder 61 formed on the feed housing to permit the resilient lingers 59 to move out of clutching engagement with the lead 52. After release of the clutch fingers 5d from their engagemcnt with the lead 52, the guide tube 5l is returned to its normal position by means of the helical compression spring 62. As the guide tube 5! approaches its normal position, the clutch collar Si is brought to rest against the bearing t@ and to wedge the resilient lingers 59 inwardly for clutching engagement against the lead 52. During the return stroke of the guide tube El, the friction collar 5l serves to hold the lead 52 against axial movement.

It will be noted that each of the two pencil constructions shown and described embodies a. split feed housing for enclosing a guide tube, the feed housing being divided longitudinally along diametrically opposed sides to form two half sections which are maintained against relative axial displacement by means of an annular flange disposed in arcuate recesses formed in the half sections. During assembly of the mechanical pencil, the guide tube is first enclosed within the two sections forming the feed housing, and the feed housing is then forced into the barrel of the pencil for snugr frictional engagement therewith. If the pencil should become inoperative for any reason, it is a simple matter to remove the feed housing and other parts from the interior of the barrel to repair or replace parts. By forming the feed housing in two sections, the cost of manufacture is greatly reduced as the sections may be inexpensively formed by die-casting or stamping operations.

While this invention has been shown in but two formait is obvious'to those skilled in the art that it is not so limited but is susceptible of various changes and modications without departing from the spiritand` scope of the claimed invention.

I claim as my invention:

l. In a mechanical pencil, a tubular housing divided longitudinally along diainetrically oppositesides to form twoisimilar abutting sections, a tubular barrel snugly enclosing said housing, a guide tube mounted within said housing to receive a writing lead, means operable responsive to movement oi saidguide tube relative to said tubular housing to movefa writing lead longitudinally through said guide tube, and a member mounted in one end of said housing, said member having an annular. flange disposed Within and preventing relative longitudinal displacement of the two sections forming the housing.

2. In a mechanical pencil, a tubular housing divided longitudinally along diametrically opposite sides to form two similar abutting sections, one end of said tubular housing being formed with an internal annular groove, a tubular barrel snugly enclosing said tubular housing, a guide tube mounted within said housing to receive a .f iting lead, means operable responsive to movement of said guide tuberelative to said housing to move a writing lead'longitudinally through. said guide tube, a member mountedin one end of said housing, said member having an annular flange disposed within said internal' annularY groove to prevent relative longitudinal displacement of the two sections forming the housing.

3. In a mechanical pencil, an internally thread'- ed tubularhousing divided longitudinally along diametrically opposite sides` to lform two abutting sections, a tubular barrel snugly enclosing said housing, a guide tube mounted witl'iinsaidv housing to receive a writing lead, said guide tube having a longitudinally extending slotY formed therein, a plug mounted within said guide tube, a shoulder provided on said plug and extending outwardly through the slot foi-med in said guide tube for engagement' by the threads of said internally threaded housing, and a member mounted in one end-of saidhousing, said member having arrannular flange disposed within and engaging the two sections of the housing against relativelorigitudinal displacement.

4; In a mechanical pencil, a tubular housing divided longitudinally along diametrically Vopposite sides to form two abutting sections, a tubular barrel snugly enclosing said housing, a guide tube mounted Within said housing to receive a writing lead, resilient fingers formed on one end of said guide tube, a clutch sleeve mounted on said guide tube to engage and move said resilient fingers into rictional engagement with a writing lead, and shoulder means formed on said housing to move said clutch sleeve into and out of engagement with said resilient iingers responsive to reciprocatory movement of said guide tube.

5. In a mechanical pencil, a tubular housing divided longitudinally along diametrically opposite sides to form two abutting sections, a tubular barrel snugly enclosing said housing, a guide tube mounted within said housing to receive a writing lead, resilient fingers formed on one end of said guide tube, a clutch sleeve mounted on said guide tube to engage and move said resilient fingers into frictional engagement with a writing lead, shoulder means formed on said housing to move said clutch sleeve into and out of engagement with said resilient lingers responsive to reciprocatory movement of said guide tube, and a helical compression spring interposed between said housing and guide tube to normally hold said clutch sleeve in engagement with said resilient fingers.

6. In a mechanical pencil, a tubular housing divided longitudinally along diametrically opposite sides to form two abutting sections, a tubular barrel snugly enclosing said housing, a guide tube mounted within said housing to receive a writing lead, resilient fingers formed on one end of said guide tube, a clutch sleeve mounted on said guide tube to engage and move said resilient ngers into frictional engagement with a writing lead, shoulder means formed on said housing to move said clutch sleeve into and out of engagement with said resilient fingers responsive to reciprocatory movement of said guide tube, a helical compression spring interposed between said housing and guide tube to normally hold said clutch sleeve in engagement with said resilient ngers, a friction sleeve to snugly receive and engage a writing lead, and annular flange means provided on said friction sleeve to engage and maintain the two sections of the housing against relative longitudinal displacement.

GARY LYNN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,568,950 Ballou Jan. 5, 1926 FOREIGN PATENTS Number Country Date 210,979 Great Britain Feb. 14, 1924