US2523568A - Pencil with mechanical means for advancing the lead thereof - Google Patents

Description

F. W. HALVERSON sept. 26, 195o INVENTQR.

, m ,A Q e f Q s a LAQ z w l z 6 a Q Q Q Q Q Q Q w H m r|. l. 74 mm Q QQ Q Q Q Q Q Q 4 +7, F 1 J 7 /,0 5 mme. z f/Q g4 ma NL9- www. MTM G 1 z A ,Q ...114| Wawy/ Q uw L ,@waw//W w 6 .f Q P Patented Sept.\26, 1950 UNITED STATES PATENT oFFl-ce PENCILWITH MECHANICAL `MEANSFOR ADVA'NCING ATHE LEAD THEREDF FondlWfHalverson, Milwaukee, Wis.

-ApplicationvMay 26, 194'8, Seria1.No.i29,3'30

(o1. 12in- 17) "This invention vrelates to imprt'rvements-v in pencils :with'step by step .feed.

Anto'bject iof the invention isftorprovide la pencil of the'type ywhereinthe user can advance the lead from ltimefto'timeto replaceithe point asit wears awayoraccidentally:breaks off.

Anothervobject fof the :invention isnto provide a lead pencil` of the 'mechanical type including anf improvedf'form and construction of clutch deviceiior. vadvancing .the 4lead from Vtime to time, meansbeing `prm/idediorfoperating the clutch by `th-e `gripping actionY of the hand holding the pencil.

A further fobiject othefinvention iste provide a lead pencil of the mechanical type having an axially compressible and reciprocable clutch or feed mechanism for advancingl the lead as it wears away, saidfeed beingdisposed well within the forward part or simulated' point of Athe pencil and controlled therefrom. l

Other objects 'will appear as the 'description proceeds. f

In the-accompanying drawings which-.forme part of this application: v

Figure l is `a longitudinal sectional view through the writing end of a mechanical pencil formed in accordance with the present invention showing the lead advancing clutch device in retracted or writing position.

Fig. 2 is a longitudinal sectional view through the writing end of a mechanical pencil formed in accordance with the present invention showing the lead advancing clutch device in lead advanced position.

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 1.

Fig. 4 is a sectional view taken on'the line 4-4 of Fig. 2.

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 2.

The same characters of reference are used throughout the following specification and the accompanying drawings to designate the same parts.

In carrying out the invention, there is shown an improved mechanical type pencil including an elongated body I formed with a screw thread 2 on its point supporting end. A molded rubber sleeve 3 is threaded upon the threaded end 2 of the pencil body I, and is formed with a constricted lower end 4 rmly secured in the annular groove 5 formed in the tip 6, which sleeve is part of a skeleton framework having a plurality of longitudinally extending radial slots 1 formed therein for receiving or accommodating inner and outer rows or stacks of spherical balls 8. A centrally disposed longitudinally extending guide tube 9 is supported Within the pencil body l for accommodating the writing lead I0, and at the same time providing a wall -against which balls .8 oitheinner row ofballsrest. .Longitudinally `extending control bars II are disposed in the slots .'I between the spherical balls 8 and the molded rubber sleevel, with vsaid sphericalballs lying vbetween said control bars I I and the centrally disposed .longitudinally extending guide tube 9 for the writing lead I0. The balls of the `cuter rowrestbetzweenadjacent balls of theinner rowf-ofballs, thespacesbetween the balls of one row` .being normally .substantially narrower vthan the diameter-.of the balls ofY the adjacent row. Thus itfwill be seen that. when the sleeve 'l is pressed. inwardly, the balls ofthe outer row will ,beforcedbetween theballsof the inner .rows, spreading the balls of the inner rows andlengthening theinner row of balls, operating `the clutch memberv `I5 to .advance the lead.

Thetiphasat its inner end a laterally extending annulariiange. I2, and is formed with a'large innerlbore .t3 and .areduced outer bore I4.

A114 inner clutchmember I5 having a laterally extending annular flange vlli on its upper. end is slidably supported onthe outer endof Lthe guide tube. 9 and isprovided with aconical inner wall .I'Land an inwardly extending annular iiangev I8 in its lower end. A coil spring I9 is disposed within the inner bore I3 about the clutch member I5 with one end contacting the annular flange I6 on the clutch member I5 and its outer end engaging the base 1 of the bore I3. The outermost of the spherical balls 8 will rest upon theV inner end of the clutch member I5 while the innermost of the spherical balls 8 will contact the adjacent end of the pencil body I.

A second clutch member 20 is Slidably disposed Within the reduced bore I4 in the tip 6 and comprises an outer ring 2| which snugly surrounds the writing lead I0 and three radial upwardly extending clutch fingers 22 which terminate with the hooked inner ends 23 which are formed with shoulders 24 extending above and supported by the annular flange I8 on the clutch member I5.

At rest, the spherical balls 8 are held in position by the pressure of the coil spring I9, being forced to rest against the guide tube 9 on the inside and the control bar I I. Pressure upon two sides of the rubber sleeve 3 forces the bars II inwardly pushing the outermost spherical balls 8 between the row of innermost balls 8, bringing into alignment allof the balls 8 in each slot. With the top ball 8 resting against the outer end of the pencil body I,r the outer ball 8 is forced a sufficient distance outward to bring about a subsequent movement of the clutch members I5 and 20 to advance or expel writing lead I0 slightly from the tip 6.

Upon release, the clutch member I5 is forced inward by the spring I9 permitting the fingers 2| to release their grip on the writing lead I0. Clutch member 20 is retarded by friction until 3 the shoulders 23 and the inwardly extending annular flange I8 are engaged. Further inward motion returns the entire clutch assembly to a normal position.

Having thus described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

1. A pencil having a body, a lead guide tube supported axially by one end of said body, a compressible rubber sleeve supported by said body concentrically about said lead guide tube, an axially bored tip supported by the opposite end of said rubber sleeve, a writing lead in said lead guide tube, cooperating clutch members in said tip,- outer and inner rows of balls supported withrin thebody, the balls of outer'rowsresting against the balls of theinner rows, separating the balls of the inner rows, and the-balls of the outer rows being movable between the balls of the inner rows in contact with the guide tube, spreading the balls of the inner rows and operating the clutch members.

2. In a mechanical pencil, a body, a lead guide tube supported axiauy of the body and in which writing lead is held, a clutch member slidable on the guide tube, engaging the writing lead advancing the lead through one end of the guide tube, a coiled spring normally urging the clutch member longitudinally of the guide tube, outer ,and inner rows of spaced balls surrounding the tube, portions of thev balls of the outer rows being normally disposed between the balls of the inner rows, and a collapsible rubber sleeve encasing the rows of balls, said rubber sleeve ,adapted to force the balls of the outer rows between the balls of the inner rows when pressure is directed thereto, lengthening the inner rows of balls and operating said clutch.

3. In a mechanical pencil, a body, a lead guide tube supported axially of the body in which a Cil vso

writing lead is mounted, a collapsible rubber sleeve having radial slots supported by said body concentrically about the lead guide tube, outer and inner rows of balls mounted within the slots, a clutch member on which balls of the inner row rest, the balls of the outer row being movable between the balls of the inner row under pressure directed to the balls of the outer row by said collapsible rubber sleeve, lengthening the inner row of balls, operating the clutch member, and a coiled spring mounted within the body adapted to return the clutch member to its inactive position.

4. In a mechanical pencil, a body, a lead guide tube supported axially` of the body in which writing lead is held, a clutch member engaging the lead advancing the lead asthe clutch is operated, a collapsible rubber tube surrounding the lead tube, outer and inner rows of balls held between-the lead guide tube and rubber tube,'a coiled spring within the body engaging theclutch member urging the clutch member against the balls of the inner row forcing the balls of the outer row outwardly against the collapsible rubber tube, the outer row of balls being movable between the balls of the inner row under pressure directed'tol the collapsible tube, operating the clutch, and means for gripping the lead holding the lead against inward movement.

FORD W. HALVERSON.

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

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