US3424538A - Pen - Google Patents

Description

#lh-'28, 1969 FRIEDRICH-WILHELM RAuscH 3,424,538

PEN

Filed Sept. l2, 1966 United States Patent O 3,424,538 PEN Friedrich-Wilhelm Rausch, Hannover, Germany, assignor to Wagner Guenther Pelikan-Werke, Hannover, Germany Filed Sept. 12, 1966, Ser. No. 578,578 Claims priority, application Germany, Aug. 16, 1966,

W 39,925 U.s. C1. 401-259 claims Inf. cl. 43k 5/00,1/06

ABSTRACT 0F THE DISCLOSURE A pen includes a barrel having a central bore at its front end and rearwardly thereof a centrally arranged closed cylindrical chamber having a narrow opening at its front end coaxial with the bore. An ink reservoir is located rearwardly of the cylindrical chamber. The

ink reservoir and the cylindrical chamber are separated by wall means. Passage means extends in the barrel alongside the cylindrical chamber and communicates with the ink reservoir and with the bore. An ink applicator is removably mounted on the front end of the barrel and provided with a central passage coaxial with the bore and the narrow opening. A cleaning unit comprises a piston element slidably arranged in the cylindrical chamber and a pin secured to and extending forwardly of the piston element so that, when the latter is in advanced position the pin projects through the narrow opening and the bore into the central passage in the ink applicator.

The present invention relates to a pen and, more particularly, to a pen having a rellable ink reservoir.

Pens of the type having a refllable ink reservoir are generally known as fountain pens, a designation which will occasionally be employed hereafter. All pens of this type are provided with nibs of one type or another which contact the paper and make thereon the ink indicia. Some of the general-use fountain pens, and most fountain pens used for drafting, are provided with nibs in form of a short tubular portion through which ink can ow from the reservoir onto the paper or other material on which indicia are to be made. The problem with this latter type of nib is, however, that quantities of ink are likely to dry thereon, or indeed to dry in the passages connecting the tubular member with the ink reservoir. This is particularly true in the case of fountain pens which are to be used for drafting purposes since these pens utilize india ink which, having a higher solids content than regular inks, is especially susceptible to forming encrustations which adversely influence or perhaps even completely prevent the further flow of ink.

Attempts have been made to overcome this and in one of these a piston-like member is disposed in a chamber in the interior of the detachable ink applicator carried by the pen, and provided with a forwardly projecting pin which is located within the tubular nib of the applicator and can freely move therein in longitudinal direction in response to any movement of the pen from a horizontal to an inclined position, or vice versa. In constructions of this type there is very little provision made for displacement of the ink when expansion of the air in the ink reservoir occurs. Accordingly, pens constructed in this manner are susceptible to smudging, since ink which is being displaced by expanding air in the reservoir, can escape only to the outside of the pen and not to an auxiliary reservoir wherein it might be collected. Furthermore, the construction of these pens is conducive to the formation of ink encrustations and requires frequent dissassembly of the pen and cleaning of the writing portions. Addi- 3,424,538 Patented Jan. 28, 1969 ICC tionally, the construction of pens of this type is relatively expensive.

In another type of drafing pen the front portion, including the ink applicator, comprises an auxiliary ink reservoir of relatively great volume which is connected with an ink feeding system. The arrangement and configuration of the ink reservoir or reservoirs makes possible a relatively advantageous compensation for temperature fluctuations and thus relatively uniform ink ow. However, in these devices the movable piston-like member with its pin is not provided since the space necessary for it is of course taken up by the auxiliary or overlflow reservoir. Thus, the formation of encrustations within the tubular nib is inevitable and the pen must then be disassembled and cleaned. This is rather ditlicult because of the relative complexity of the ink feeding system connecting the nib with the overow reservoir.

It is therefore a general object of the present invention to provide a pen as set forth above which is not subject to the disadvantages of the prior art.

A more specific object of the present invention is to provide such a pen in which the formation of encrustations in the nib is eliminated or at least largely prevented.

A concomitant object of the invention is to provide a pen of the type outlined above in which a uniform ink ow from the ink reservoir to the nib is assured.

In accordance with one feature of my invention I provide a pen which comprises an elongated pen barrel provided at its front end with a central bore and rearwardly therefrom with a centrally arranged closed cylindrical chamber having a narrow opening at its front end arranged coaxially with said central bore. An ink reservoir is provided in the barrel and is located rearwardly of the cylindrical chamber separated therefrom. Passage means are provided in the barrel, including a portion which extends alongside of and is spaced from the cylindrical chamber and communicates at one end with the ink reservoir and at its other end with the bore at the front end of the barrel, an ink applicator is removably mounted on the front end of the barrel Iand is provided with a central passage arranged coaxially with the bore and the narrow opening, and a cleaning unit is provided, including a piston element slidably arranged within the cylindrical chamber and movable between a retracted position nearer to the ink reservoir and in an advanced position nearer to the narrow opening of the cylindrical chamber. The cleaning unit further includes a pin which is secured at its rear end to the piston element and extends forwardly therefrom, such pin projecting in advanced position of the piston element through the narrow opening and the bore in the front end of the barrel into the central passage of the ink applicator.

In accordance with an important feature of the invention the length of the path along which the piston-like member can move, as well as the length of the pin are so arranged that in the retracted position of the piston-like element the front end of the pin is located within the central bore in the front end of the barrel. Thus, the ink applicator can be readily exchanged for an applicator of different type while the piston-like element is in retracted position without fear of damaging the delicate pin. On the other hand, when the piston-like element moves to its advanced position the pin will project into the nib of the ink applicator. Thus, any movement of the pen from a horizontal to an inclined position and vice versa will cause shifting of the piston-like element and consequently of the pin into and out of the nib of the ink applicator, thereby cleaning this nib of ink deposits or encrustations.

In accordance with the invention it is important that the space Within which the piston-like element is slid- \f encrustations which might tend to preclude movement of the piston-like element.

Also the ink is in contact with the air only at the point :at which it leaves the front end of the nib, so that the formation of ink encrustations is further reduced by this expedient.

Furthermore, the invention provides for an auxiliary or overflow ink reservoir of relatively great volume which permits use of the pen under all atmospheric conditions `without any significant changes in the ink ow.

The novel features which are considered as characteris tic for the invention are set forth in particular in the ap pended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a partial cross-section in longitudinal direction through a pen in accordance with the present invention; and

FIG. 2 is a section taken on the line II-II of FIG. l.

Discussing now the drawing in detail, and firstly FIG. 1 thereof, it will -be seen that the front section 1 of the pen is provided with an internal shoulder 2 and is connected via screw threads 3 with a rear portion of the barrel, namely with an ink reservoir-containing portion 6. An elastically compressible sealing ring 8 is advanta geously provided which is compressed between the por tions 1 and 6. By constructing the face 11 at the front end of the rear portion 6 in forwardly slanting direction the sealing action becomes particularly effective.

The front portion 1 houses an inner sleeve comprising a back portion 4 and a forward portion 5. Located within this inner sleeve is a guide sleeve 7. The inner sleeve is provided with a radially projecting ange portion 9 which is received within the front portion 1 of the barrel and which is provided with an eccentrically located annular capillary groove 10 which at its narrowest point as seen with respect to the Ibore of front portion 1 is connected with the interior of the ink reservoir `6 by a longitudinally extending groove 12 whereas at its widest, oppositely located point it is connected via a longitudinally extending groove 13 with an overflow reservoir 18. The back portion 4 is provided at its forward end with a means for securing thereto the forward portion 5, for instance by pushing the front end of the portion 4 into the rearwardly directed opening of the forward portion 5.

The forward portion 5 is provided with two or more annular grooves 14 and 15 which are in communication with one another and which further communicate via an air chamber 16 with the ambient atmosphere and via an additional air channel 17 with the overflow reservoir 18. None of these channels are of capillary type.

The forward portion 5 is `also provided `with a radial shoulder 19 which engages the inwardly directed shoulder 2 at the front end of portion 1 against which it is pressed when the sealing ring 8 is placed -under axial compression, as has been indicated before.

Guide sleeve 7 is located within the portions 4 and 5 and extends over the entire length thereof in such a manner that an annular capillary passage 20 exists between the inner wall of the portions 4 and 5 on the one hand and the outer wall of the drive sleeve 7 on the other hand. This passage 20 serves for conducting the ink.

The guide sleeve 7 is, as will be evident from the drawing, centered and supported, preferably at its conically tapering front end, by supporting projections 21 provided at the conically tapering bore of portion 5, and the depth of these projections 21 is such that a capillary passage is formed between the same and the sleeve 7. At the rearward end the sleeve 7 is secured and centered by having an axial projection 22 provided on the back portion 4 extending into its central chamber 32. Of course, this axial projection 22 simultaneously serves to close off the rear end of sleeve 7 and to thus define the aforementioned central chamber 32.

The cleaning unit, comprising an axially slidable piston member 23 which carries at its front end a forwardly projecting pin 24, is slidable within this chamber 32. When the novel pin is tilted such that its forward end points in downward direction the piston member 23 moves to an advanced position in which the pin projects through the bore 25 of sleeve 7 into the bore 26, which is of greater cross-section than the bore 25 since through bore 26 ink must ow whereas it is desired that ink-flow through bore 25 be prevented, and into the tubular nib 27 of the ink applicator 28. The total length of the pin 24 and the piston 23, as well as the extent of axial movement of the latter, are so arranged that in the retracted position of the piston 23 the front end of the pin 24 does not project beyond the bore 26 and is thus protected if the ink applicator 28 is exchanged or removed, whereas in advanced position of the piston 23 the pin extends completely through the nib 27 and slightly projects beyond the open front end thereof.

As is evident from the drawing the outer wall of back portion 4 is not cylindrical but rather slightly conical in such manner that it tapers towards the front of the pen. A particularly advantageous capillary action can be obtained in this area if the wall is of hyperbolic outline, which is not shown in the drawing. In either case, there is created an annular space serving as overflow reservoir 18 of such configuration that automatic filling thereof with fluid from the reservoir 6 is not possible. However, if fluid is displaced, for instance by heating and expansion of the air in the reservoir 6, then this overflow reservoir 18 fills uniformly and without the inclusion of any air from the rear end of reservoir 18 to the front end. Normally, only the narrowest portion of the eccentric annular groove 10 and the annular groove 12 receives ink. To assure that annular groove 10 is definitely provided with ink a capillary longitudinally extending groove 29 (see FIG. 2) is provided at opposite sides of the longitudinally extending groove 12 parallel thereto.

As has been pointed out, the portion or end wall 22 closes off the chamber 32. It is carried by the back portion 4 and is preferably a separate member. It is provided with several longitudinally extending ribs 30 angularly spaced and of such height that several arcuate capillary passages 31 are established between the bore of the back portion 4 and the peripheral face of wall 22, and it is these capillary passages 31 which connect the annular capillary groove 20 with the ink reservoir 6. The annular capillary groove 20 is of constant cross section since there is no shoulder at the joint between the bore of rear portion 4 and forward portion 5. The latter, as is evident from the drawing, carries the ink applicator 28 with the tubular nib 27 and is secured thereto, preferably by means of screw threads.

The operation of the novel device will be obvious from what has been said before and from a consideration of the drawing. Ink flows from the reservoir 6 via the passages 31 through the annular capillary groove 20 to the bore 26 in forward portion 5, and from there into the nib 27. In the area of bore 26 and of the nib 27 it flows about the Ipin 24, which, because of its movable arrangement, makes it possible to keep the bore 26 of forward portion 5 and the interior of the tubular nib 27 free from ink encrustations in the simple manner described above without requiring disassembly of the pen. Entry of ink into chamber 32 of guide sleeve 7 is completely or substantially prevented since the bore 25 is so narrow that it is filled by the pin 24. Replacement air for ink Withdrawn from reservoir 6 fiows through air channel 16, the annular grooves 14 and 15 which are connected with one another, and the subsequently arranged air channel 17 into the overflow reservoir 18 between the front section 1 and the back portion 4. From there it passes through the eccentric annular groove via the longitudinal groove 13 and the longitudinal groove 12 and into the ink reservoir 6, breaking at intervals through the ink contained in the annular groove 10 and the longitudinal groove 12.

It is not believed necessary to show how the ink reservoir 5 is filled since this can be done in conventional form from an ink container or by means of cartridges. A cap will of course be provided for protecting the front end of the pen and it should be noted that this can be placed onto the pen without requiring removal of the ink applicator 28. The ink applicator 28 can, of course, be replaced With a different type of applicator if desired.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of a pen differing from the types described above.

While the invention has been illustrated and described as embodied in pens, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint `of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A pen comprising, in combination, an elongated pen barrel provided at its front end with a central bore and rearwardly therefrom with a centrally arranged closed cylindrical chamber having a narrow opening at its front end arranged coaxially with said central bore; an ink reservoir located in said barrel rearwardly of said cylindrical chamber and separated therefrom; wall means interposed between said ink reservoir and said cylindrical chamber and sealing the latter against entry of ink from the former; passage means in said barrel including a portion extending alongside of and spaced from said cylindrical chamber communicating at one end with said ink reservoir and at its other end with said bore at said front end of said barrel; an ink applicator removably mounted on the front end of said barrel and provided With a central passage arranged coaxially with said bore and said narrow opening; and a cleaning unit, including a piston element slidably arranged within said cylindrical chamber and movable between a retracted position nearer to said ink reservoir and an advanced position nearer to said narrow opening of said cylindrical chamber, said cleaning unit also including a pin secured at its rear end to and extending in forward direction from said piston element and projecting in advanced position of the latter through said narrow opening and said bore in said front end of the barrel into said central passage in said ink applicator.

2. A pen as defined in clairn 1, wherein said pin is of such length that the front end thereof in retracted position of said piston element is located within said central bore in the front end of said barrel.

3. A pen as defined in claim 1, wherein the crosssectional area of said central bore is greater than the cross-sectional area of said narrow opening.

4. A pen as defined in claim 2, wherein said pin is of such length that the front portion thereof in advanced position of said piston element is located within said central passage of said ink applicator.

5. A pen as defined in claim 1, wherein said barrel comprises a rear section within which said ink reservoir is located, and a front section removably secured to said rear section and comprising said front portion.

6. A pen as defined in claim 5, wherein said front section includes an outer sleeve member secured to said rear section and having an open front end, and an inner sleeve having a back portion received in said outer sleeve with peripheral clearance so as to define therewith an annular space and also having a forward portion connected to said back portion partially located within said outer sleeve and sealing said annular space and partially projecting outwardly beyond said open front end of said outer sleeve.

7. A pen as defined in claim 6, said inner sleeve further comprising a guide sleeve received within said forward and back portions of said inner sleeve and defining therewith said portion of said passage means, said piston element being located within said guide sleeve.

8. A pen as defined in claim 7, wherein said passage means is an annular capillary passage of constant crosssection.

9. A pen as defined in claim 7, and further comprising centering means for centering said inner sleeve with respect to said outer sleeve.

10. A pen as defined in claim 1, wherein said passage means comprises a plurality of capillary channels communicating with said ink reservoir and with said portion of the passage means.

References Cited UNITED STATES PATENTS 2,891,512 6/1959 Kovacs 4011-258 X FOREIGN PATENTS 1,244,806 9/ 1960y France.

LAWRENCE CHARLES, Primary Examiner.

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