US2514610A - Mechanical pencil - Google Patents

Description

July l1, 1950 A. scHwElTzER '2,514,610

MECHANICAL PENCIL,

Filed June 4, 1946 -2-..-ii-----:.:iasiHWWH Patented July 11, 1950 MECHANICAL PENCIL Arnold Schweitzer, Geneva, Switzerland, assignor to Fabrique Suisse de Crayons Caran dAche S. A., Geneva, Switzerland, a. corporation of Switzerland Application J une 4, 1946, Serial No. 674,226 In Switzerland March 13, 1946 The present invention relates to mechanical pencil and is an improvement over a type of pencil comprising an outer shell having at one end a conical seat, a lead guiding tube carrying at one end jaws clamping the lead when in said seat, a controlled spring urging the tube inwardly and the jaws to their seat, auxiliary jaws normally urged to lead clamping position through openings in the tube, but retracted from lead clamping position by a central cam during the spring-urged back stroke of the tube.

This otherwise satisfactory pencil structure has the. disadvantages of a high production cost, of the complicated shape of the auxiliary jaws and of the diiliculty of accurately positioning the cam retracting the auxiliary jaws.

These and other disadvantages are overcome by the embodiment of the present invention.

The present invention has for its object a leadholder of the type cited above and which tends to avoid the inconveniences mentioned owing to the fact that a stationary clamping organ is provided in the shell, the arms of the auxiliary jaws having a portion cooperating with said stationary clamping organ in such a manner as to cause the elastic application of said auxiliary jaws on the lead engaged in said leads guiding tube when said control member is actuated against the action of said restoring spring, and so as to maintain said auxiliary jaws and said lead in a fixed position with respect to said shell while said leads guiding tube performs a portion of its back stroke, this back stroke being caused by said restoring spring when said control member is released by the operator, whereby the automatic forwarding of the lead between the clamping jaws is produced.

The annexed drawing shows diagrammatically and by way of example two forms of construction of the lead-holder.

Fig. 1 is a view of an axial section of a form of construction with some portions removed, the lead being clamped in its position of service between the clamping jaws.

Fig. 2 is a similar view, with the clampingr jaws in a forwarded position.

Fig. 3 is a similar view of a second form of construction, the lead being in a forwarded position between the clamping jaws, these latter being represented in an intermediate position taken during their back stroke.

The lead-holder represented on the drawing by way of example comprises after the fashion of other known lead-holders:

An outer shell I, of general cylindrical shape, with a pointed end in which a conical seat 2 is .A prises a member sliding freely along the leads 4 Claims. (Cl. 1Z0-17) provided. A leads guiding tube 3 carrying at one of its ends clamping jaws 4 emerging from this pointedv end of the shell, is subjected to the action of a restoring spring 5 tending to maintain jaws 4 applied on conical seat 2. This leads guiding tube bears at its other end a leadsv magazine AI5 covered by a control member 1 emerging from the end of shell I opposite to the clamping jaws 4.

The lead feeding device of the invention comguiding tube 3 between two extreme positions determined by two abutments I0 and ll. This sliding member is provided with twoauxiliary jaws I2 traversing the'wall of the leads guiding tube 3 through longitudinal openings I3. These auxiliary jaws are borne by elastic arms 14 rigidly connected at one end to an annular portion` l5 engaged over the leads guiding tube 3. Arms I4 have a shoulder I5 cooperating, when the control member 1 is actuated, with a clamping organ constituted by a shoulder I1 of shell I, and on which rests the restoring spring 5 of the leads guiding tube. The portion ofthe shell I located between this shoulder I1 and the pointed end i has van axial vhole I9 of a smaller diameter than the bore 20 of the portion of the shell extending from this shoulder to the'other end. Y

In Fig. 1, the elements of the lead-holder are represented in the position of rest, the lead 8 being maintained in its position of service by clamping jaws 4. These latter are applied on the lead owing to the action of the restoring spring 5 tending to jamb the jaws in conical seat 2.A y f l When the user desires to cause the forwarding of the lead between the clamping jaws, it is sufli-4v cient for him to exert an axial pressure on the control member 'I against the action of the re.- storing spring 5 in order to bring -the various members of the lead-holder into the position rep- S resented in Fig. 2.

Control member 'I drives with it leads magazine 6 leads guiding tubev 3 and clamping jaws 4, all these parts being rigidly connected one to the other. During this movement, abutment II constituted by the frontal face of magazine 6 comes in contact with a rear face IB of the ring portion I5 of the sliding member and drives the latter for the latter portion of the forward stroke of the control member 1.

During the movement of the sliding member, shoulders I6 of elastic arms I4 slide over shoulder Il of the shell and enter hole I9 of smaller diameter, which causes the clamping of aux- ,iliary jaws I2 upon the lead 8 (Fig. 2). y

' As previously indicated, the' jaws 4 cooperate ber l.

they are drawn into the socket by the-spring..F

5, but when the control member.` I ismovedto When the lead is in writing position.

push the tube 3 downwardlyth'ejaws.are .moved out of the seat 2 but the jawss4l @still clamp thelead with sucient friction to prevent the lead from falling from between s'aid jaws. As-`shown.

in Figure 2 the lead 8 has been'givemadisplace ment of the same magnitude of the control memsocket as the displacement stroke of the tube 3 proceeds# the vauxiliary` jaws 2. which have-,been applied/.by virtue of the.-shoulder. I 6 vof vthermembers L14: ridingvoverthe shoulders ill; the lead -8 willl be i pushedf through the jaws-,1l aA suflicient amountA toy provide the-additional: length of lead :Icr writingV 'purposess Whenvzthe'user'freleasesf'control member "I, restoring-spring.` =causes--a: back.` motion of leads guiding tube 3 and clamping jaws 4. Neverthe@ lesszzthesliding member'. the elastic arms I4f'of which are brought.v together in the inside pinhole I94 of f'shell :.I is; maintained'stationarywith respect to. thesshell byithefriction ofarms I-4'and thefwalls fof." thefholef;I I9.; Auxiliary,A jaws-1 I2 maintain; thus @the lead 1in:Y ai fixed position with respect to.: shelL'I` andstlexfjawsz-g4 can-:slide over the lead! The-free stroke. of'thefsliding .member iis limited by in on'edirecti'onl theterminalf walls'of the When the jaws 4 are moved out'of '-the.;

two# longitudinal slots.: I3, ,inzwhichf auxiliary andtakes the Aslid'i'ngfnrenriber along fortheflatter portion Aof- 'the fbackward movement of l'the :leads guiding tube. This-movementof theA sliding member causes the disengagement of the-'elastic arms I4 fromy the hole I9Iand fromthefsh'oulder I'If andtherefoie the =liberation yofilead 8f-rom the auxiliaryjaws. Towards rthe end 'of-.the back stroke of the leads guiding ftube A3, 'clampingjaws 4 vfengaging' witl- conical seat 2,2 become clamped on lead '8 "(Fig. 1) Tand maintain'same in its Aposi. tion of service:

From the above; it mayb'efseen, that thedescribed leads-holder, although-containing only al veryY small "number" of vrparts asy compared with known` leads-holders operates in" an.I absolutely safe' manner. n

Furthermore, no part or 1 constitutive imember. of this leads-holder necessitates accuratezmae. chining; This peculiarity represents. a great technicaladvantage-*and ensures. a long service life--to the describedfleadseholder. Lastly, the assemblyfof` the latter is exceedingly easy and rapid-'iasit-does not necessitateany adjustment.

Furthermore, in the above described." leads' holder'thef elasticity of 'arms I4 must be only sucientfto prevent a took high pressure from being exerted by auxiliary:jaws I21on lead 8. This velastic characteristic does not require any special property of the jaw arm I4.. Further, the frictions r'are much smallerzthan in known leadsholdersvso that restoringfspring 5Jdoes `notneed to be strong.

In: the form of"A construction represented? in 4 Fig. 3, a sleeve 22 with an axial hole I9 is slipped in the bottom of axial hole 20 of outer shell I. The edge of this sleeve is shaped into a collar forming the shoulder Il on which rests restoring spring. 5. Clamping jaws 4 are carried by a tubularholder 23, the/end .of which v`is screwthreaded. The free end of the leads guiding tube 3 :is also provided with a screw thread. A screw threaded nipple 24 holds together holder 23 and leads guiding tube 3.

From theeinspection of Fig. 3, it may be seen that ;thefassembly;of the described leads-holder is Vvery'quickH and easy. Indeed, after the sleeve 22 has been'V placed in the outer shell I and the slidinggmember has been slipped over the leads guidinggtube'and the nipple 24 has been screwed to the free end of the latter, it is suicient to sli'prrestoring spring 5 over` the sliding member and to introduce the whole in the outer shell I. Bye exerting a pressure onthe -endof'the magazine-f6," spring l-5 is maintained inV its compressed position andthe clamping jaws viv may be introduced through the pointed end of the Ashell andI screwed :into nipple 24. After filling magazine-61 with'leadal and' placing over `it control 'membern "I theleads-jholder is ready foruse.4

One of Vthe'greaifadvantages of the described leads-holder` consists inthe fact ithat the amplitude of the forwarding'movement'iof vthelead isalways the same and 'equals the amplitudeof the vfreestrokeof the sliding member from. one tcV the `other of the twoabutrnents I0 'and II..

I claim:

l. In a propelling pencil .the.combination.com-` prising, an outer shell havinga-.conical. seatin one end, a` lead.. guid.ing.tube.disposed. in ,said shell, lead gripping` jaws. carried by the lower end of .the-tube.and...normally engaging said seat tormly holdthe. leadin writing position, said jaws when projectedout of theseat being adaptedv .to-.clamp-.the-'lead less .firmly topermit its. movement between the jaws,` spring .means held at-one end kbysaid .shell a controlsmernber in said.shell andl connected to..saidtubefandv eir-l gaged by said-spring means andthereby urged to a position Vprojecting.:through the other end of said.shell,. means in, saidrv shell and-guided' by said-"tube and. engageable at itsY upper end. by said control` member land having at its lower endauxiliary lead engaging andfieeding jaws normally urged toleadreleasing position, elongated openings.A in said .tube providing said auxiliary j awsaccess to. theyleadand a path. ofi movement lengthwise of said tube, cam means in said shell engageable by said auxiliary jaws after the out' wardf propulsion` ofsaid tube: by the inward movement of .thecontrol,memberand after the release of the lead by said vgripping jaws and upon continued :inward movement of y said control member, said camY meansurging said auxiliary jaws to leadr clamping.l position, whereby inward movement of said control member will propeLsaidvtube-ain said shelli outwardlyk of said casing and disengageA saidigripping jaws from said seat and thus :partially release ysaid jaws from' thezlead .and then move said means guided bysaid' tube and force. said auxiliary jaws into engagement with said cam means to cause same to clamp the lead:throughv said openingsand to Imove the'lead in said tube outwardly'through said `released gripping 'jaws and whereby upon release of said controlmember the ends-of said. openingsmove saidauxiliary'jaws and said means guidedfby saidrtubeiztosaf position inrwhich said' auxiliary jaw means are disengaged from said cam means.

2. In a propelling pencil, the combination according to claim 1 and wherein said shell is 'provided with shoulder means holding said spring means and camming said auxiliary jaws upon continued inward movement of said control member.

3. In a propelling pencil, the combination according to claim 1 and wherein a sleeve is dis- 10 posed within said shell for holding said spring means and camming said auxiliary jaws upon continued inward movement of said control member.

4. In a propelling pencil, the combination, acl cording to claim 1 and wherein the means in said shell and guided by said tube is engageable at its upper end by said control member after initially stressing said spring.

ARNOLD SCHWEITZER.

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

UNITED STATES PATENTS Number Name Date 1,803,794 Deutsch May 5, 1931 2,078,433 Winter Apr. 27, 1937 FOREIGN PATENTS 5 Number Country Date 219,430 Switzerland May 16, 1942-

Images