US2274702A - Mechanical pench - Google Patents

Description

March 3,'1942. H. R. JocHlM MECHANICAL PENCIL Filed April 2l, 1941 INVENTOR.

/\TTORNEY Patented Mar. 3, 1942 UNireo STATES PATENT oFFlor-1vr MECHANICAL PENCIL;

Helmet R. Jochim,v Chicago, Ill. assignor to Rite- Rite Mfg. Co., Chicago, Ill., a corporation of l A Illinois Application April 21, 1941, serial4 No. 389,593

(Cl. 12o- 181)V 4 Claims.

This invention relates to an improvement in mechanical pencils, and consists of the matters hereinafter described and more particularly4 the pencil, it is arrested in either positionby' a suitable stop. An attempted rotation of the-head f member in one or the other direction beyond its position when one of said points is reached is apt to damage the lead-feeding mechanism of the pencil.

While means has been provided in pencils of the kind to notify the user of the pencil by a clicking noise that the end of the advance or-of the retracting movement of the lead clutchY has been reached, this noise is not always eective to prevent the pencil user from continuing the rotative movement of the head beyond the point that it should go.

The object of the present invention is to provide a mechanism in a pencil of the kind whereby when the lead clutch reaches the said limits of movement a further rotation of the lead-feeding mechanism will be made ineffective by reason of an improved drive cup which operates the drive stud and includes a yieldable friction clutch to prevent undue pressures from being transmitted. y

The advantages of the invention will appear more clearly as I proceed with my specication.

In the drawing, the pencil and its parts are shown on a greatly exaggerated scale in order that the details of construction may be more readily seen.

Figure 1 is a front view in elevation of the improved pencil, with parts broken away and shown in section in order that the mechanism of the interior may be seen.

Figure 2 is a top plan view of the improved drive cup on a still greater exaggerated scale.

Figure 3 is a view showing a vertical cross-section through Figure 2 in a plane indicated by the line 3-3 of Figure 2.

Figure 4 is a perspective view oi a dished washer which. is oneT elementof theimproved driving y cup.-

Figure 5 isv a view representing a horizontal section of Figure p1 in a plane indicated by the line 5--5 of Figure 1.

Referring now to that embodiment of the invention illustrated in the drawing: I0 indicates the barrel. This is made in two parts, an upper part I0a and a lower part I0". .The latter is provided with a tapered tipvlin, the usual manner. an eraser and also designed for rotating the operating assembly.` I'I/ indicatesa metal sleeve extending the length ofthe upper part Illa of the barrel and frictionally engaged therein. Said sleeve projects beyondY the upper end of the barrel part Il)a to receive a cap I. Adjacent the upper end-of thebarrelLv Ia'the sleeveA is provided with an indented groove I-2 whichA is engaged by a ring I3.` This-'helps tol retainthe sleeve-in the barrel.

Within the loweramember Ib-of the barrelis the operating assembly I4. includinga spiral I5y and a longitudinally slotted tubev Id'acontaining .therlead clutch and ejecting rodr xedwithin the lower barrel part IOb-in a familia-rmanner. Saidf assembly includes adr-ive stud I6 projeeting'at the top and fixed to the rotative member thereof, in this case the spiral I5, in the usual manner. Surrounding the operating assembly I4 and mounted in the lower barrel part Illb is a sleeve I1. Said sleeve is of greater diameter than the diameter of the operating assembly so that a cylindrical space I'Ix is left to provide a reservoir for leads.

The upper end of said sleeve II is split and is preferably provided with an annular groove I'Ia to yieldingly engage an associated annular rib I Ih formed in the sleeve I I to yieldingly hold the two parts Ila and IIllD of the barrel together. A knurled split nut I8 yieldingly held on the driving assembly I4 closes the upper end of the mag- .azine.

Obviously by the construction described the -upper part IIIa of the barrel may be withdrawn Illd indicates the familiar cap enclosing Within which is seated in the cup an operating disc 2|. Said operating disc has a central aperture provided with annularly spaced V-shaped notches 2|a opening towards the center of said disc with their apices preferably disposed radially to said center. The stud as shown is polygonal (rectangular as shown) in cross-section and its edges are adapted to be engaged by said notches.

22 indicates a. dished spring washer seated on the top of said operating disc and engaged at its upper edges by metal tongues 23 preferably cut from the interior metal of the cup ange I!!a and bent down into engagement with the rim of said operating disc 2|. `An auxiliary washer 24 is preferably disposed between the bottom of the operating disc and the bottom of the drive cup as shown in Figure 4.

The bottom of the dished spring washer 22 is yieldingly engaged against the top of the operating disc 2| so that normally when the upper part I t'la of the barrel is rotated, said rotation will be communicated through the operating disc 2| to the drive stud I 6. But when the lead clutch reaches the limit of its movement at either end of the barrel so that it cannot with safety be moved any further, the dished Washer 22 will yield, and further rotation of the operating disc is prevented.

From the foregoing description, it will be seen that kthe invention includes a'drive cup and a friction clutch made up of a few parts, readily and easily assembled. When it is remembered how small these parts are in actual pencils, the advantage of this feature will be fully appreciated by those familiar with .the art.

I claim as my invention:

1. In a mechanical pencil of the kind described, including a barrel made in two parts, one rotative with respect to the other, an operating assembly including a drive stud mounted in the non-rotatable part, a drive cup provided with an annular flange Xed within the rotatable part of said barrel, anapertured disc seated in said cup provided with means for engaging said drive stud, and a yielding member engaged with said apertured disc, the ange of said cup being provided with circumferentially spaced tongues projecting inwardly and engaged with said yielding member.

2. In a mechanical pencil of the kind described, including a b-arrel made in two parts, one rotative with respect to the other, an operating assembly including a drive stud mounted in the non-rotatable part, a drive cup .provided with an annular flange xed within the rotatable part of said barrel, an apertured disc seated in said cup provided with means for engaging said drive stud, and a yielding member engaged with said apertured disc, the flange of said cup being provided with circumferentially spaced tongues struck from the metal of said flange, projecting inwardly from said flange, and engaged with said yielding member.

3. Y In a mechanical pencil of the kind described, including a barrel made in two parts, one rotative with respect to the other, an operating assembly including a drive stud mounted in the non-rotatable part, a drive cup provided with an annular flange xed within the rotatable part of said barrel, an apertured disc mounted in said cup provided with means for engaging said drive stud, and an apertured dished washer engaged with said apertured disc, the ange of said cup being provided with circumferentially spaced tongues projecting inwardly from said flange and engaged with the margin of saidspring dished washer.

4. In a mechanical pencil of the kind described, including a barrel made in two parts, one rotative with respect to the other, an operating as- .'sembly including a drive stud mounted in the non-rotatable part, a drive cup provided with an annular ange Vfixed -within the rotatable part of said barrel, an apertured disc mounted in said cup provided with means for engaging said drive stud, and an apertured dished washer engaged with said apertured disc, the flange of said cup being provided with Ycircurnferentially spaced tongues struck from the metal of said ange, projecting inwardly from said flange, and en- :gaged with said yielding member.

HELMER R. JocHIM.

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