US2400768A - Fountain pen - Google Patents

Description

D- F. MOHNS May 2l; 1946.

FOUNTAIN PEN Filed ont. 12, 1944 l INVENTOR Z/QPNOLM lfinest extreme operating conditions ceed that amount which:

PatentedMay 2119f016` David F. Molins,

Parker Pen Company, anesville, Wis., a corpol ration of Wisconsin Application octtber 12,1944,seria1N0.5'5a,381

`si Claims. i w1. 12o-f4.7)

generally to fountain pens fountain pen My invention relates and has to do particularly with a provided with a multiple-stroke filling device of the type including a breather tube extending from the feed structure of the pen into the ink reservoir thereof. f

The principal object of my invention is to provide 'an improved fountain pen of the foregoing character.

Another object is to provide a fountain pen having provision for preventing leaking and nooding, and particularly a fountain pen well suited for use in airplane travel.

A further object is to provide a fountain pen of the foregoing character having provision for automatically preventing such change in the normal pressure relationship existing. between the air within and outside of the reservoir, when a reduction of atmospheric `pressure occurs, as' would cause iiooding or leaking of the pen.

Still another object is to provide a fountain pen of the foregoing character wherein the length of the breather tube is such relative to the volumetric i,

capacity of the ink reservoir that proper pressure conditions within the reservoir to prevent leaking or flooding are maintained.

l. A still further object is to provide a fountain pen of the `foregoing character `wherein the breathertube is so located in the reservoir as to provide for automatic re-establishment of the normal pressure relationship existingbetween the air within and outside of the reservoir, upon reduction of atmospheric pressure.`

A more specific object is to provide a fountain pen of the foregoing character wherein the breather tube has a free and open end projecting into the ink reservoir and terminating interme-l the` reservoir short of the volu` thereof so that the end of the be open to the air inthe reserdiate the ends of metric mid-plane breather tube will `voir in at least horizontal and point-up positions of the pen.

A further object is to `providea fountain pen o f g the foregoing character .which is so constructed andarranged that be dischargedJfromtheink' reservoir under the does not exwhich the feed mechanism is capable of retaining without leaking and flooding.

I Other objects and advantages will become apparent as the following description progresses and by reference Figure 1y is a longitudinal sectional view on an enlarged scale, showing a fountain pen embodying FOUNTAIN PEN Janesville, Wis., assignor to'Thef the amount. of ink' that may to the accompanying drawing, in`

the features of theinvention, with the pen in a vertical or filling position. l

Fig. 2fis a view showing the pen with its point end up as when carried in the pocket. f .5 l Fig.-3 is a viewshowlngthe penfin `writing position. l j l l l Fig. 4` shows the pen in horizontal position as when lying on a desk orin a handbag. j l

The fountain penfwhich I have chosen to illustrate my invention comprises a barrel I0, the interior of which constitutes an ink reservoir. It

l front end of the barrel in communication with the v f In the broaderfaspects of the l ink reservoir Il. inventionany suitable vfeed `structure capable of .use with a multiplestroke filling device may be employed. However, the particular feed structure shown herein, and `in connection with which my invention has special utility, vis ofthe type dis- 25 closed in ,United States `I etters Patent Non 2,223,541 granted to Marlin S. Baker on December 43, 1940. Other forms of feed structure that may be used are illustrated in ted States Letters 30 Patent Nos. 1,980,508 grantedfgto Ivan D. Tefft on November 13, 1934,` and 1,904,358 granted to ArthurQDahlberg on Aprils 18, 1933.

The feedstructure illustrated (Fig. ilincludes an ink governor or collector device I3 mounted in the front end ofl the barrel III incommunication 35 with the ink reservoiri I. This governoris providedl with a capillaryl ink feed passage Il inter- `secting a plurality'of annular capillary` cells I5 adaptedto receive and store ink that may `tend 46 tofiowfro he reservoir II through the feed passage ,irri-excess of that required for writing purposes. The governor I3 receives and supports a ,feedjrpar I6 and a tubular pen point I1, these ihffparts being arranged to provide capillary passages IS connecting with thefeedgpassage I4 and i the writing tip I8 of the pen nib I1, as more fullyy 'described in said Baker Patent No. 2,223,541. The governor I3, `feed bar I6 and pen nib I'I, except the writing 'tip I8 of the latter, are enclosed within 50 a shell I9 secured to the forward end of the pen barrel by a bushing member 20. i In the use of the feed structure just described, air is permitted to flow to the reservoir I I through `an opening!! in the forward end of `the shell 5 I9 and `thence through the rearniost capillary `governor vcelll or cells I5, `when they'a're free of ink, to bubble back to the ink reservoir through the rear end of the ink passage I4. The admission of air to the reservoir in the normal writing operation is necessary in order that ink may be withdrawn from the reservoir for writing purposes; but when, after a condition of flooding or leaking and the capillary governor cells I5 have ink therein, air cannot pass therethrough to the ink reservoir so that feeding of further ink from the reservoir is 'discontinued and ink is taken only from the governor structure in further writing until the governor cells are again clear.

A cap 22 is adapted to be detachably fitted to the front end of the pen for protecting the writing point thereof when the pen is not in use, which cap, if desired, is adapted to be iltted upon the rear of the barrel when the pen is in use.

Referring to Fig. 1, a filling device, indicated generally at 23, of the multiple stroke type, such as shown in said Dahlberg Patent No. 1,904,358, is secured at the rear end of the barrel I0. This filling device includes a flexible diaphragm 24 actuated by a reciprocable plunger 25 to vary theeifective volume of the reservoir II to cause ink to be drawn thereinto in the manner fully explaned in said Dahlberg patent. That is to say, on each complete stroke of the filling plunger 25 a small quantity of ink is drawn into the reservoir so that the reservoir maybe filled to a predetermined extent upon the completion of a plurality of strokes.

'I'he filling device 23 further includes a socalled breather tube 26 which has one'end supported within an opening in the rear end of the feed bar I6 in communication with the capillary ink passage I4 and its other end extending rearwardly within and in communication with the ink reservoir. As taught by the Dahlberg patent, air is expelled through the breather tube 26 in the operation of the filling plunger 25 and the relative displacement of air and ink upon actuation of the plunger 25 is such as to cause the filling of the pen as above mentioned.

It will be appreciated that in the use of a lling device of the type illustrated in Fig. 1, the filling of the reservoir may be continued by multiple stroke action until the level of the ink in the. reservoir reaches the open end of the breather tube. Should the filling operation be continued after this, ink may be drawn into the reservoir in an amount equal to that which is drawn into ,thev reservoir during one filling stroke, thereby raising the level of the ink in the reservoir to that thereof. To this end, in the last lling stroke, the front end of the pen may be lifted from the ink supply from which it is being lled and the filling plunger 25 released after such removal so that in the very last suction stroke there is drawn into the ink reservoir ink in an amount not exceeding the capacity of the governor I3. Therefore, it will be obvious that in the pen of the particular type shown, the ink level will not be extended beyond the end of the breather tube 26 to an extent in excess of the volume of ink that may be stored in the governor I3.

In pens of the type shown in said Teift and Dahlberg patents, Nos. 1,980,508 and 1,904,358, respectively, the last filling stroke-may be completed with the front end of the pen immersed in the'body of ink from which the pen is being filled. In that case, upon complete filling, the amount of ink in the reservoir beyond the open end of the breather tube will not exceed the volume of ink drawn into the reservoir on one normal filling stroke of the pen.

In prior pens embodying the foregoing type of lling mechanism, the breather tube has always been of such length as to extend in close proximity to the rear end of the ink reservoir so as to enable the filling of the reservoir substantially completely. This has presented a seriousdifficulty from the standpoint of leaking and flooding in airplane travel. For example, with the foregoing prior breather tube arrangement, when the pen point is in an inverted or upright position, as when carried in ones pocket, the open end of the breather tube is completely submerged in the ink in thereservoir and, during air travel, in the ascent of the plane the reduction in th'e outside -air may become such that the pressure of the air in the reservoir acting on the ink extent above the open end of the breather tube.y l

If the filling Operation is continued after the latter condition exists, ink instead of air will be forced out by the filling device, upon depression of the filling plunger 25, so that regardless of additional filling strokes, substantially the same amount of ink will be forced out as is drawn in, no air being forced out because, under the condition stated, the end of the tube is covered with ink, and air cannot be forced out until the ink level is reduced to uncover the end of the tube. Therefore, it will be seen that the extent to which the reservoir may be filled, i. e., the maximum ink level in the reservoiris determinable by the length of the breather tube 26.

'I'he type of pen disclosed in the drawing isy well known in the trade as the 51? pen` manufactured and sold byThe -Parker Pen Company of Janesville, Wisconsin. In lling this pen it is desirable that the filling operation be carried out in such a way that the governor I3 is substantially cleared of ink upon the completion will cause ink to be discharged from the reservoir through the breather tube and the capillary passages connected therewith. In this case, the open end of the breather tube remains submerged until the reservoir is almost empty, and the amount of inkdischarged may be in excess of the capacity of the feed mechanism to absorb the same so that excess ink leaks or floods at the writing tip of the pen into the closure cap (corresponding to the closure cap 22) which will then be in place on the front end of the pin. If this condition exists removal of the cap 22 for use of the pen in the airplane will result in smearing of ink upon ones hands and clothing. My invention completely avoids the foregoing objectionable' condition and provides a pen in which ch'angesof pressure within the reservoir relative to the outside atmosphere will not cause ink tobe forced from the pen to cause leaking or flooding at the writing tip ,5 I6 thereof in any position of the pen. Tdtheforegoing end the breather tube 26 is positloned-.poncentrically in the reservoir II and is of such-length relative to th'e volumetric capacity of-the reservoir Il that its open Aend is at all times open to the air space in the reservoir in the inverted or point-up position of the pen.

Specifically, I attain the foregoing result by positioning the inner or open end of the breather tube 26 at such apoint between the oppOsite ends i ofthe reservoir that the maximum level of the cated at 28 in Fig. 2 when the pen is in point-up or inverted position. yMore particularly, the reservoir II is of such length and diameter that.

o a accuses 3 after the feed and filling mechanisms are assemwill be below the open end of the breather tube 4 bled as shown, the volumetric mid-plane thereof 1 26 inthe writing position ofthe pen, and theprop- '(a plane perpendiculargto the longitudinal axis e t er pressurecondition may be established through of the reservoir anddividingthe volumetric cathe breather tube without inkxbeingdischarged paclty ofthe reservoir into two equal parts) is lo- 6 I into the governor or feed means. e v s, y cated on the line AiFigs. land 2).,andthe inner l I claim:` l .l eA, j end of the breather tube 26 terminates lshort or 1. Aifountain'pen comprising areservoinafeed forwardly of the volumetric mid-planeby a disstructure, and a multiple stroke` filling devlceintance greater than on -halfthe longitudinal dicluding Aa breather tube extending `freinsaid feed mension in the reservoir of the'volume of ink that 10 structure intosaidreservoir, the inner endof said can be taken inon one suction stroke of the llbreather tube beingshort of the volumetric miding device. In this arrangementthe volume of i 1 planeof said reservoirby a distance greater than the reservoir II forwardly of the inner end of one halfthe'longitudinal dimension in the reserthe breather tube 26 is less than the vclume'rear- -voir of the ink thatcan be `tfalfzeniri by onesuc-I wardly thereof. 'f 15 tion stroke `ci! thenllingdevice whereby theellevel Y, When thepen is in its point-.11D Position (Fig. of the ink will be below the `ende of, the breather 2), the open end of' the breather tube 26 will tube when the penis positioned withthepolnt end alwayslieintheairspaceinthereservoirsothat up. .l L l I if there is any tendency to disturb the normal 1` 2. A fountain pen comprisinga reservoinafeed pressure relationship between the air within and structure secured tothe front end of the reservoir, outside of the reservoir, asin airplane travel. and a multiple stroke nlling device mounted in which would otherwise causea dischargeofink Y' the rear end.of the reservoir and. including a from the reservoir, such pressure relationship will breather tube extending from said feedlstructure be automatically reestablished through' the into said reservoir, the rear endofsaidbreather breather tube, preventing discharge of ink from `tube being spaced. forwardlygof the volumetric the reservoir. midplane of said reservoir bye, distancegreater t When using a completelyfilledpen in writing .than one half the longitudinaledimension` in thel position, the ink Awill assume a1 level such as in- 1 reservoir of the volume of inkthat can betaken l `dicated at 32 in Fig. 3.] In thiscase the volume ini `on oneysuction stroke` of thefiiling`" device,

e of the ink above vthe open end of the breather 3o whereby the level of the inkwill be below the end tube is no greater thanthe capacity of the govl of the breathertube when the pen isy positioned ernor I3. Therefore, if in this case, the normal withjthefront end up. 2 i pressure relationship is disturbed suiiiciently to -l 3. -Afountainpen having an ink reservoir, an-

cause discharge of ink from the reservoir,` I I, the s c ink feed connectedwith said reservoir, and filling amount of ink discharged would not exceed the 85 mechanism for said reservoircomprising `a dis-l capacity of the governor I3 andit'wouldA be taken placement element, andan air. discharge :element up therein without flooding or leaking at the writ` projecting from said `ink feed into the e reservoir ing point of the pen. l only to apoint. where theink drawn in on the In the horizontal position of the pen, as shown last suction stroke of the displacement element" in Fig. 4, the ink will assume a level, indicated 40 will fill the reservoir to a level spaced above the at 33, which is only slightly above the axis of the volumetric mldplane of the reservoir a `distance breather tube 26 because the latter is concentric less than one half the longitudinal dimension in with the reservoir. Thus, the inner end of the the reservoir of the ink that can be taken in by l breather tube 26 will be located at least partially one suction stroke of the displacement element within the air space' in the reservoir. Since air 45 whereby said air discharge element extends into will pass through the breather tube and feed the air space in the reservoir when the `pen is structure more easily than ink, a disturbance of positioned with its front end up. the normal pressure relationship wilicause air, 4. A fountain pen comprising a reservoir, ink rather than ink, to be discharged from the resfeed means in the front end of the pen, filling ervoir. While tilting the pen so that the point 5 means in the rear end of the pen. and air disis down will tend to shift the ink level above the charge means in said ink feed means, said lling end of the breather tube, the ink above the end of means inc1uding a tubular element constantly in the breather tube will be forced from the reservoir e communication with `Said air diseharge means into the cells 2l),I as when the pen is in writing and opening into the reservoir at a point between Position, and n0 leaking or flooding will Occur. 55 said ink feed means and filling means and deter- Thus, in a pen construction in accordance with mining the level towhich said filling means can my invention, the rear end of the breather tube fill said reservoir, said pointbeing so located that will be within the air space in the reservoir for the volume of the reservoir f0rward1y of said point,` normal carrying positions of the pen, and conis less thanthe volume of said reservoir rearward-` sequently upon disturbance of the normal presly of said level, whereby said element opens into n sure relationship, air alone will be forced out of the air space in the reservoir when thefront end the reservoir through the feed structure. Should is up; n the pen be completely filled and used for writing 5. A fountain pen comprising a barrel provid under such conditions, or carried with the point ing a reservoir, a feed structure secured tothe w l `end, down, only 'so much ink as can be stored in 55 front end of the barrel, and a multiple-stroke the cells20 will be discharged from the barrel. lling device mounted in the rear end of the y Thus in no case will the pen be caused tov leak or barrel and includingV a breather tube 'extending flood at the writing tip. The pen may therefore rearwardly in andconcentrically with said reserl be safely carried and used during airplane travel. voir from said feed structure, the inner end of The foregoing description takes a completely said breather tube being spaced'forwardly from filled pen into consideration, which is the maxithe volumetric midplane of said reservoir by a mum condition that can be imposed. However, distance greater than one-half the longitudinal e it will be appreciated that in many conditions of dimension of the volume of ink that can be drawn -f use (which will be the case in the majority of into the reservoir by one suction stroke of the instances) the level o: the ink in the reservoir 7 mung device. i

inner end short of the volumetric midplane of the reservoir a distance greater Athan one-half Vthe longitudinal dimension in the reservoir of the 4ink that can be taken in' by one suction stroke of' the filling device whereby flooding or leakj ing 'of the penis prevented when the normal pressurerelationship between air. within and outside of'the reservoirl is disturbed for any position ofthe pen.

7. A fountain pen-'comprising a'reservoir, a

feed structure having an ink passage from said reservoir and means for storing excess ink opening directly ,into said ink passage, andl a multiple-stroke filling device including a breather tube voir forwardly of said point is less thany the volume rearwardly therefrom by an amount greater than the volume of ink that can be taken in on'one suction stroke of the filling device, whereby leaking or flooding of the. pen is pre- "vented when the normal pressure relationship y between the air within and outside of the reservoir is disturbed for any position ofthe pen. 8. A fountain pen comprising a reservoir, a feed structure havingan ink passage and means said feed structure into said reservoir with its i y y extending from said feed structure into said resj 'ervoir to a point where the volume of said reser- Y plane of thereservoir a` distance greater than one-halfthe longitudinal dimension in the reservoir of the ink that can be taken in by one suction strokeof the fillingdevice, the ink in said excess ink storage means being withdrawn therefrom into the reservoir 'at the conclusion of the lling operation whereby any ink discharged from the reservoir by a disturbanceof the normal pressure relationship between the air within and outside of the reservoir, when the point end is down, will be taken up by said excess ink storage means.

9. A fountain pen lcomprising a reservoir, a feed structure at the front end ofthe pen having an ink passage from said reservoir and capillary ink storage cells opening into said ink passage, anda multiple-stroke filling device at the rear endof the penv including a breather tube extending rearwardly from lsaid feed structure into said reservoir andl determining the level to which said filling device can ll said reservoir, the inner end of said breather tube being so located that the volume of the reservoir forwardly of said inner end is less than the volume of said reservoir rearwardly 0f said level whereby the breather tube opens into the air space in the reservoir whenA theY front end of the pen is up, the Linl: entering said cells during filling being' withdrawn into the reservoir by a suction stroke of theV filling device at the conclusion for storing excess ink in direct communication with said reservoir, and a multiple-stroke fill- 4ing device including a breather tube extending of the filling operation whereby the maximum quantity of ink from thereservoir that will be discharged therefrom by a disturbance of the normal pressure relationship between the air within and outside of the reservoir. when the point end is down .will be equal to the capacity of said cells and will be taken up thereby.

I DAVID F. MOI-DTS.

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