US2930354A - Alternate push rocking latch mechanism for retractable ball pen - Google Patents

Description

March 29, 1960 J. c. LocKwooD ALTERNATE PUSH ROCKING LATCH MECHANISM FOR RETRACTABLE BALL PEN 2 Sheets-Sheet 1 Filed Dec. 3l, 1956 INVENTOR. JOHN c. Locxwooo A TTORNCYS March 29, 1960 J. c. LOCKWOOD ALTERNATE PUSH RocxING LATCH MEcHANIsM FOR RETRACTABLE: BALL PEN Filed Dec. :51, 1956 2 Sheets-Sheet 2 "fr, i.

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ALTERNATE PUSH ROCKING LATCHMCHA- NISM FOR RETRACTABLE BALL PEN John C. Lockwood, Atlanta, Ga., assigner to Scripta, Inc., Atlanta, Ga., a corporation of Georgia Application December 31, 1956, Serial No. 631,771

Claims. (Cl. 1Z0-42.03)

This invention relates to ball point writing instruments and more particularly to an improved latch mechanism for such writing instruments in which a writing unit is arranged for projection and retraction alternately upon successive depression of a plunger member.

Briefly described, the latch mechanism of the present invention is characterized by a iloating latch member adapted for disposition within a pen barrel at the rear end of a writing unit retractably housed therein and forwardly of a depressible plunger member, and shaped for sliding longitudinally in the barrel upon depression of the plunger member into contact therewith as well'tas for selective, transverse, fulcrumed rocking in opposite directions in the barrel as a result of such contact; the -'oating latch member and the depressible plunger member having the adjacent ends thereof formed for ContactY in alternate relations so that each successive depression of the plunger member causes rocking of the latch member in the direction opposite to that of the preceding depression and thereby operates to project land retract the writving unit alternately. Y Y By this arrangement of the floating latch member a number of important advantages are obtained in thelatch mechanism provided by the present invention. In the first place, a wide choice is allowed in selecting a specific design for the latch memberso that no compromise is '2,930,354 Patented Mar. 29, 1961) the operating mechanism in the position it occupies when the latch member is being disengaged to lpermit retraction of the writing unit; and

Fig. 7 is a partial, longitudinal cross section showing' the operating mechanism in the position it occupies when the writing unit is being retracted as the latch member en; gages the rear latch shoulder to position the latch member for a new operating cycle.

The writing instrument 10 comprises a two-part barrel housingy formed by a forward barrel portion v12 anda rear barrel portion 14. A writing-unit or ball point and reservoir unit'16 is slidably arranged within the forward barrel portion 12 for projection forwardly to a writing position through an opening in the tapered Writing tip of the forward barrel portion 12 and is continuo-usly biased rearwardly for retraction therein by a barrel springilS seated forwardly on an inwardly stepped inclined annular shoulder 20 formed in forward barrel portion 12. The other extremity of barrel spring 18 bears against shoulder 22 formed exteriorly on the ball point and reservoii unit 16. vThe forward barrel portion 12 is reduced in diameter and threaded'adjacent itsrear end as at 24 for assembly with rear barrelportion 14 fitted for this purpose with an internally threaded assembly sleeve 26; assembly sleeve 2,6 having an opening therethrough forallowing the ball point and reservoir unit 16 to extend into rear barrel portion 14. A cartridgeV plug 28 is fitted within the rear end fof yball point and reservoir unit 16 and has a central longitudinal aperture 29 extending therethrough andV exterior grooves 30 spacedron the outer surface of cartridge plug 28."V A

cap coverV 32 is tted overthecar'tridge plug 28 and allows venting to the atmosphere through grooves Silthat extend necessary in regard to such factors as strength and ease of manufacture. Also, the floating nature ofthe latchmember eliminates any highly critical tolerances in shaping it to the related structure with which it must operate, and further eliminates the difficulty of vany articulated assembly about `a pivot axis or the like. prior attempts to provide a rocking latch means have always introduced arrangements that required the latch to be a captive of or attached to other parts of. the operating mechanism. As a consequence, the floating latch member of the present invention makes it possible to provide an exceptionally effective alternate push latch mechanism having consistent and serviceable operating characteristics and arranged so thatv it is particularly easy to assemble.

These and other featuresiof the present invention are described in further detail below` in connection with the accompanying drawings, in which:

Fig l is a central, longitudinal cross section of the writing instrument according to the present embodiment of the invention;

It is recognized that v beyondY the forward end of cap cover 32." The'writing iny unitsrandis not intended to be limited to any specic Fig, 2 is an exploded perspective View of the writing in- I writingunit.

The operating mechanism ofthe present invention is contained within housing 36 which is divided longitudif f nally into two sections 38, 4l) as shown in Fig. 2. An Y insert 42 of Achannel Vshape in cross section, vhaving a forward latch shoulder'44 formed on Vone side of the channel section-and a rear latch shoulder 46'formed by the other side thereof, is arranged within a grooved portion 48 in housing section 38. An adapter cup 50 is arranged'oiver the rear end of the ball point and reservoir unit 16 and is disposed within housing sections 38, 4); a cup shoulder 52 being arranged interiorly of sections 38,40 for limiting the forward movement of adapter cup 50. A latch member 54 contacts the rear kendY of` the adapter cup 50 and is limited in its forward movement by the adapter cup 5l) abutting cup shoulder 52, thereby restricting the forward movement of latch member`r Latch member 54 is unattached to any of the parts 'of the Writing instrument and is a freely floating ltnemlier being free to move longitudinally andwto `rock transversal? to'shift the ball point and reservoir unit 16 between retracted and projected positions. The rear end of`latch member 54 is formed witha pair of oppositely arranged, inclined, outwardly facing cam surfaces 56, 58 that .converge at a point substantially on` the longitudinal axis of latch membertSi. Latch member'54 is furtherformed adjacent its forward end with two oppositely arranged llaterally extending latch arms 60, 62; the configuration of latch member 54 being substantially symmetrical ywith a T-shaped or arrow head appearance.

ITl`he latch member 54 is rockably `cammed into and out of latching Arelation with forward latch shoulder 44 about latch rockers 67, 68 respectively,thatare disposed 'slightly rearward of the midpoint ofthe longitudinal xis'of latch member 54. The maximum trans'versedi- Vrnension of 'latch member S4 is between the laterally Aextending latch arms 60, 62 and this .dimension Visso designed to be less than the transverseinterior dimension "of the .mechanism housing 36 between forward latch 'shoulder 44 and rear latch shoulder 46. It is noted *that the transverse interior dimension of mechanism l'verse 'aperture 72 extending transversely through the 4forwardly :extending portion of plunger member v7|)l and -'dapt'edto receive and containV a plunger Aspring 74that continuously biases plunger member 70 rearwardly. A

springstud 76 isarranged on the rear'edge of the aper- 4turef72'andthe'rear end of spring 74 isarranged around :."stud', Aplunger retaining stud 78 is formed Yonthe 'housing Ysection 38and limits the forward and rearward movements of plunger member 70. The forward end of `plunger member 70 is formed with oppositely arranged inclined strike faces 80, 82 that converge at a point substantially on the longitudinal axis of plunger member70 `andthe longitudinal axis of the barrel. lA rearwardly facing plunger spring shoulder 84 is arranged within vmechanism housing sections'38, '40 providing a seat for the plunger spring 74.

"In assembly, the forward portion of mechanism housing 36 receives `the rear portion of assembly sleeve 26 and is V'secured-'thereto by an outwardly Adisposed Abarb 86 on assembly sleeve 26. A lock sleeve 88 is tted 'over the downward-stepped rear portion of mechanism housing "3.6and` secures the rear `ends of mechanism housing sec- `tions 4'38, 40 together.

A clip`member 90 is vfixed, on 'rear barrel portion 14 by ears 92 extending Athrough'slots '93 in the rear barrel portion 14, and lock sleeve 88 has -slot 94therein that abuts the clip member ears 92. A trim -ring 96 having a clearance aperture therethrough to receive plunger member 70 for slidingmovement therein is arranged about the end of the rear barrel portion 14; the clearance aperture being alignedV withthe rearportion'fof lock sleeve 88 and being of a `similar 4coniguration.

VIn operation, referring first to Figure '3 in whichlthe ball point and reservoir unit 16 is in retracted position withllatch varm 62 in abutting relation with rear latch shoulder '46, the latch member 54 is Iurged rearwardly nnder--the `bias Vof barrel spring 18 andv induces rocking of latch member 46V about latch arm 62, therocking pre- `-v'er'rted -by 'latch rocker 67 abutting the inner wall of insert'42 Ywithin mechanism housing 36. Upon depression of` plunger member 70 when the ball point and VV"r"1`cl'-"fo`rcing latchmember `54 forwardly with latch arm `i'$lidablyengaging the inner wall of insert 42 within the 4 mechanism housing 36 until forward latch shoulder 44 is reached;`1atch varm 60 then being rocked about rocker 67 to latched engaging relation with forward latch shoulder 44 as shown in Figure 4, and the ball point and reservoir unit 16 is thus latched in projected posi-tion.

Upon the release of plunger member 70 from the latched Vposition shown in Figure 4, the rearward force exerted by barrel-spring 18 is transmitted totheforward canted bearing surface of latch member 54 and rocks latch member 54 about latch arm 60 until latch rocker 68 contacts the inner wall. of insert 42 within the mechanism housing 36 as shown in vFigure 5; plunger member 70 returning to its extended position after each depression under the .bias-of plunger spring 74. It is understood that plunger spring 74 is not a necessary element for satisfactory operation but is used to return the plunger 70 in each instance to its extended position. The latch member cam surface 58 is thus exposed for contact with the plunger strike face l82 upon the next succeeding depression of plunger -member 70.

To release the'ball point and reservoir unit 16 from projected position, plunger member 70 is depressed and strike face 82 contacts latch member cam surface 58 as illustrated in'Figure 6 and the camming action therefrom results in a rocking of latch member 54 about rocker 68 in a clockwise Adirection and the unlatching o'f rocken arm 60 from engagement with forward 'flatch shoulder 44. 'i'he'latch member 54 is rocked untilrocker arm'62 contacts the opposite interior side of mechanism housing, 36 from rocker arm 60; (latch member54 then moving'rearwardlyiun'der Lthe action of 'barrel spring '1'8 until latch arm 62 contacts rear latch shoulder 46 `'as shown in "Figure 7.

As plunger member54 moves rearwardly from the position shown in Figure 7 under the force of plunger spring 74, the rearward force exerted by barrel springulS is 'transmitted to the forward canted bearing surface of latchrnember 54 and rocks latch member 54 about latch arm 62 until latch rocker 67 contacts the interior wall of insert`^42'within mechanism housing 36 as in Figure '3, thus'exposing latch cam surface 56 for contact with plunger memberstrike face upon `the next succeeding depression of the plunger member 70.

It is noted that the plunger strike faces 80, 82 alter. nately engage alternate latch cam surfaces 56, 58 upon successive `depressions of the Vplunger member 70 as.' a resultof the rocking o'f the latchmember S4 about latch arms 60, 62 Aafter the plunger member 70 is releasedfrom Ycontact with latch member 54.

The present invention has been described above for purposes of illustration only and is not intended to be limited by-this description lor otherwise except as described in the appended claims.

Iclaim:

'1. In a ball point writing instrument havingfa barrel, a writing unit slidably arranged within said barrel for retracted and` projected positioning with respect thereto, and rmeans'continuously biasing said writing unit rearwardly within said barrel toward retracted positionythe improvement comprising a rockable latch member 'arranged in fulcrumed relation with respect to the -rear -en'dl-of 'said writing Yunit and within `said barrel Yand floating freely thereat to move longitudinally and to rock transversely `in opposite directions, but -onlyein a singleplane, -incident to shifting of 'said unit tbe tween retracted and projected positions, the forward end of said latch member having oppositely `extending latching arms formed thereat, and the rear end ofrsaid latchy member having a pair of oppositely arranged, rearwardly facing surfaces that converge at a point substantiallyonf-'thelongitudinal `axis of said latch member, means-farrangedinteriorly lof said barrel for successive 4engagement :by 'said :latch Amember :arms to :latchf'said writingfunit respectively at said `projected :and retracted positions against the force of said biasing means, said engaging means bemg laterally offset with respect to said latch member for engagement by said arms uponrocking of said latch member, and depressible actuating means arranged in said barrel rearwardly of said latch member and having forwardly facing surfaces thereon for alternately engaging the surfaces of said latch member, one of the surfaces of said actuating means being engageable with a related surface of said latch member to propel and rock the latch member to a position for latching the writing unit in projected position upon a rst depression of said actuating means, and another surface of said actuating means being engageable with the other surface of said latch member to rock the latch member oppositely to a position for unlatching the writing unit and permitting retraction thereof upon a subsequent depression of said actuating means, all without requiring any rocking of said writing unit.

2. In a ball point writing instrument having a barrel, a writing unit slidably arranged within said barrel for retracted and projected positioning with respect thereto,- and means continuously biasing said writing unit rearwardly within said barrel toward retracted position; the improvement comprising a rockable latch member having latch rocker portions at the sides thereof arranged in sidewise fulcrumed relation with respect to the inner wall of said barrel for rocking thereon and floating freely at the rear end of said writing unit to slide longitudinally and rock transversely in opposite directions within said barrel incident to shifting of said unit between retracted and projected positions, the forward end of said latch member having oppositely extending latching arms formed thereat, and the rear end of said latch member having a pair of oppositely arranged, rearwardly facing surfaces that converge at a point substantially on the longitudinal axis of said latch member, means arranged interiorly of said barrel for successive engagement by said latch member arms to latch said writing unit respectively at said projected and retracted positions against the force of said biasing means, said engaging means being laterally offset with respect to said latch member for engagement by said arms upon rocking of said latch member, and depressible actuating means arranged in said barrel rearwardly of said latch member and `having forwardly facing surfaces thereon for alternately engaging the rearwardly facing surfaces of said latch member to apply an actuating force thereat, one of the surfaces of said actuating means being engageable with a related surface of said latch member t0 propel and rock the latch member, about the latch rocker portion thereof that is against the inner barrel wall, to a position for latching the writing unit in projected position upon a rst depression of said actuating means, and another surface of said actuating means being engageable with the other surface of said latch member to rock the latch member oppositely, about the latch rocker portion thereof that is then against the inner barrel wall, to a position for unlatching the writing unit and permitting retraction thereof upon a subsequent depression of said actuating means, all without requiring any rocking of said Writing unit.

3. A writing instrument comprising. a barrel, a writing y unit slidably housed within said barrel for shifting between projected and retracted positions with respect thereto, means within said barrel biasing said writing unit toward retracted position, a rockable latch member slidably oating in sidewise fulcrumed relation within said barrel at the rear end of said writing unit to slide longitudinally and rock transversely in opposite directions Within said barrel, said latch member being unattached to said writing unit or to said barrel and having latch rocker portions at the sides thereof for rocking against the inner barrel wall, means arranged interiorly of said barrel for successive engagement by said latch member to latch said writing unit respectively at said projected and retracted positions against the force of said biasing means, said means being laterally offset with respect to said latch member for engagement upon rocking of said latch member, and a depressible plunger member Aslidably carried at the rear end of said barrelV for depression into operating contact with said latch member, theoperating contact of said plunger member being suchlas to apply an actuating force for rocking said sidewise fulcrumed latch member alternately on said latch rocker portions against said inner barrel wall incident to longitudinal movement of said plunger within said barrel for shifting said writing unit between projected and retracted positions.

4. In a writing instrument comprising a barrel, a writing unit housed within said barrel and arranged for shifting between projected and retracted positions therein, and means disposed within said barrel biasing said writing unit rearwardly toward retracted position, a depressible plunger slidably carried in the rear end of said barrel, aV latch member floating freely for relative transverse movement at the rear end of said writing unit and having latch rocker portions at the sides thereof disposed in a sidewise fulcrumed relation within said barrel for rocking against the inner wall thereof forwardly of Vsaid plunger, said latch member being engageable by said plunger to slide longitudinally and to rock transversely in one direction within said barrel about one of said latch rocker portions upon engagement of a given contact surface on said plunger with a given paired contact surface on said latch member and to rock in the opposite direction about the other of said latch rocker portions upon engagement of a second contact surface on said plunger with a corresponding paired latch member contact surface, incident to shifting of said writing unit between retracted and projected positions by said plunger member, without requiring any rocking of the writing unit, and laterally offset means within said barrel engaging and securing said rocked latch member in latching relation at said projected and retracted positions against the force of said biasing means.

5. In a writing instrument having a barrel, a writing unit slidably arranged for alternate retraction and projection with respect thereto, and means continuously biasing said writing unit rearwardly within said barrel towards retracted position; the improvement comprising a rockable latch member floating freely at the rear of said writing unit having latch rocker portions at the sides thereof and arranged in sidewise fulcrumed relation with` -in said barrel to rock transversely in opposite directions against the inner barrel wall and to slide longitudinali;l within the barrel incident to shifting of said unit between retracted and projected positions, the forward' end of said latch member having oppositely extending latching portions formed thereat, and the rear end of said latch member having rearwardly facing surface areas that conn verge at a point substantially on the longitudinal axis of said latch member, means arranged interiorly of said barrel for successive engagement by said latch member to latch said writing unit respectively at said retracted and projected positions against the force of said biasing means, said barrel means beingy laterally offset with respect to said latch member for engagement by said extending latching portions upon rocking of said latch member, and depressible actuating means arranged in said barrel rearwardly of said latch member and having forwardly facing surfaces thereon for engaging the rearwardly facing surface areas of said latch member to apply an actuating force thereat, said actuating means engaging ,the rear end of said latch member on that side of said latch member opposite from the side that is in engagement with said barrel means to rock said latch member in sidewise fulcrumed relation about one of said latch rocker portions from engagement with said barrel means into position for engagement with the opposite portion n.7 post'ip'as -fresetftunderthe force of-saijdibasing means 52863;.421 for npposite'foperating coutactwith 'sadz actuating :means '2,865,331 upon:themen-succeeding depression thereof.

:References Cited `in the ilelof this ,patent 5 v2 017 UNITED STATES PATENTS `53,926 2,584,569 'Fremzel Feb. 5, 1952 '840,819

8 lRizzo Dec. 9, 1958 Marcotte Dec. 23, `1958 FOREIGN PATENTS 'Great Britain of 1890 Germany Oct. 10, 1890 France Jan. 23, 1939

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