US3836266A - Tube writing pen - Google Patents

Abstract

Capillary writing pens of the type having a housing defining a reservoir which communicates with a capillary writing tube extending through the lower end of the housing. The reservoir is characterized by the definition of a plurality of radially spaced capillary grooves extending inwardly from the walls of the reservoir into the writing tube, so as to suspend writing ink, regardless of inversion of the pen and to enhance flow from the reservoir into the writing tube. The writing grooves may be defined in a frustum at the lower end of the reservoir and, as well, may extend longitudinally along the walls of the reservoir into the frustum.

Description

in States Lorenz et a1.

[ TUBE WRITING PEN [75] Inventors: Ewald Lorenz, Uelzen; Wilhelm Schlink, Anderten; Bruno lKiinzler, Koldingen; Klaus-Dieter Goltermann, Hannover-Kleefeld, all of Germany [73] Assignee: Koh-ll-Noor Rapidograph, llnc.,

Bloomsbury, NJ.

[22] Filed: July 20, 1973 [211 App]. No.: 331,316

[30] Foreign Application Priority Data July 21, 1972 Germany 2235880 May 24, 1973 Germany l 2326431 [52] US. Cl. 401/259 [51] Int. Cl 843k 11/06, B43k l/lO [58]. Field of Search 401/258-260, 401/216 [56] References Cited UNITED STATES PATENTS 2,627,844 2/1953 Johnson 401/259 ll/l970 12/1973 Dahle l v 401/259 Linz 40l/2l6 Primary ExaminerLawrence Charles Capillary writing pens of the type having a housing defining a reservoir which communicates with a capillary writing tube extending through the lower end of the housing. The reservoir is characterized by the definition of a plurality of radially spaced capillary grooves extending inwardly from the walls of the reservoir into the writing tube, so as to suspend writing ink, regardless of inversion of the pen and to enhance flow from the reservoir into the writing tube. The writing grooves may be defined in a frustum at the lower end of the reservoir and, as well, may extend longitudinally along the walls of the reservoir into the frustum.

7 Claims, 1 Drawing Figure rues WRITING PEN BACKGROUND OF THE INVENTION The invention relates to a capillary writing point with a cylindrical body receiving the capillary in its front end, which cylindrical body has an inside bore accommodating a falling weight with a cleaning wire, the front end of said bore has an area tapering forward in the manner of a frustum.

In the case of conventional capillary writing points, the front area of the falling weight has been flattened laterally, in order not to impede the in-flow of drawing ink from the inside bore to the writing capillary by the falling weight resting at the front end of the inside bore. However. it turned out that in the case of such conventional capillary writing points difficulties can occur whenever the points are held pointing upwards for a brief period of time, so that the drawing ink flows back out of the inside bore into the reservoir for the ink. In the case of subsequent use a breakdown in the supply flow of the drawing ink to the writing capillary can occur, since under certain circumstances air has settled in the frustum shaped area, which prevents the subsequent inflow of drawing ink from the inside bore to the writing capillary.

DESCRIPTION OF THE DRAWINGS FIG. ll, is a fragmentary, vertical section, partially in perspective, showing positioning of a conventional weight and cleaning wire assembly within the lower end of an ink reservoir, modified according to present invention.

SUMMARY OF THE INVENTION It is an object of the invention of creating a capillary writing point in which such breakdowns in the inflow of the drawing ink are assuredly prevented.

This will be achieved in the case of a capillary writing point, according to the present invention, in that at least in the frustum shaped area, radially spaced ribs are provided which are inclined inwardly and run essentially in the direction of the longitudinal axis of the cylindrical body. The spaces between the ribs form capillary grooves.

The capillary grooves will hold drawing ink even, if the capillary writing point with the writing capillary tube is held pointing upwards. Upon subsequent writing use when the writing tube is pointed downwardly, a connection is re-established between the drawing ink remaining in the capillary grooves with the drawing ink in the inside bore or reservoir, so that an undisturbed flow of drawing ink is assured.

In addition, the radially spaced ribs forming the capillary grooves have the advantage that a flattening of the falling weight at the front end is no longer required, as long as the outside diameter of the falling weight is smaller than the maximum inside diameter of the frustum shaped area.

Frequently, the annular space between the falling weight and the inside bore or reservoir wall has been developed relatively small, so that the volume of drawing ink sustained in the inside bore and prevailing at the rear end of the writing capillary tube will not become too large. Such a smaller annular space will prevent, under certain circumstances, a timely flow of drawing ink to the writing capillary tube after the return of the India ink into the drawing ink reservoir. Also, it may occur that the supply flow of drawing ink to the inside bore after inverting the capillary writing point into a position with the writing capillary tube point upwards, will remain interrupted for some time, because an air bubble settles for example in the area between the falling weight and the capillary writing tube. Such an air bubble interrupts the inflow of the drawing ink. In both such cases the India ink, which is held in the capillary grooves, is initially consumed without there being any possibility of drawing ink flowing in. In order to prevent with certainty a breakdown in the flow of drawing ink into the capillary in such cases, notch type capillaries may be provided in the inside wall of the reservoir, which are connected with the capillary grooves in the frustum area.

The notch type capillaries, also. retain a part of the drawing ink in the reservoir wall, because of their capillary effect. Even in case of drawing ink flowing backwardly from the annular space between wall and weight and into the reservoir for the drawing ink, the notch type capillaries will discharge said drawing ink into the capillary grooves upon subsequent use. Thus, even in case of a prolonged interruption of the inflow of draw ing ink from the reservoir to the annulus, an undisturbed operation is assured.

DESCRIPTION OF PREFERRED EMBODIMENTS The cylindrical body 1 has an inside bore or reservoir 4, in which a falling weight 2, with a cleaning wire 3, is contained. Cleaning wire 3 extends through a central bore to the writing capillary in the front end of the cylindrical body, which has not been shown.

At the lower end of the inside bore 4, there is a frustum shaped transition area starting from the shoulder 7 pointed inwardly, in which there are radially spaced ribs 5, which run essentially in the direction of the longitudinal axis of the inside bore. Grooves 6 have been formed between the ribs 5, which have a capillary effect.

In the wall of the inside bore 4-, there are notch type capillaries 8, running in an axial direction, which extend radially inwardly as at 8 into a capillary groove 6. In the present embodiment, three such notch type capillaries are provided, two of which are shown. Naturally, the number of notch type capillaries 8, just like that of the corresponding notch grooves 6, can be adapted to pertinent operating conditions and dimensions and all or a few of the capillary grooves 6 can be connected with a notch type capillary 8.

The notch type capillaries 8, just like the capillary grooves 6, will retain drawing ink, even if the capillary writing point is held pointing upwardly, so that upon subsequent use, the drawing ink retained in the capillary grooves between the radially spaced ribs and the ink retained in the notch type capillaries will flow into the writing capillary tube and an early connection to the drawing ink flowing subsequently into the inside bore will than have been established by way of the notch type capillaries 8. As a result. a continuous influx of drawing ink into the writing capillary tube will be assuredin any case.

We claim:

1. In a capillary writing pen of the type including an ink reservoir communicating axially with a capillary writing tube at one end, and including a weight supported in the reservoir with cleaning wire extending from the weight into the capillary writing tube, the improvement comprising:

A. a radially inwardly extending frustum having the large diameter thereof communicating with said reservoir and the small diameter thereof communicating with said capillary tube;

B. said frustum being inclined forwardly and inwardly towards said writing tube and in the direction of ink flow;

C. said frustum being defined by a plurality of spaced ribs extending substantially longitudinally and inwardly angled increasingly towards said writing tube;

D. said ribs defining therebetween capillary grooves communicating with said reservoir and said writing tube with said grooves extending radially inwardly from the periphery of said frustum to the axis of said writing tube; and

E. the inner ends of said capillary grooves each defining a longitudinally extending feeding aperture spaced about the periphery of said writing tube.

2. A capillary writing pen as in claim 1, including at least one longitudinally extending groove defined in the wall of said reservoir and communicating at its forward end with at least one of said radially spaced grooves in said frustum.

3. A capillary writing pen as in claim 2, said longitudinally spaced groove being V-shaped notched in cross section.

4. A capillary writing pen as in claim 2, said longitudinally extending groove and said radially spaced groove both being similarly notched in cross section, so as to define a continued notched capillary groove extending from the sides of said reservoir, through said frustum and into the writing tube axis.

5. A capillary writing pen as in claim 4, said frustum including a peripheral outer shoulder at the juncture with said reservoir and said longitudinally extending grooves and said radially spaced grooves registering through said shoulder.

6. A capillary writing pen as in claim 1, wherein said weight defines a relatively small annulus for ink flow adjacent the inner wall of said reservoir.

7. A capillary writing pen as in claim 1, wherein said weight outer diameter is less than the diameter of said frustum at the juncture with said reservoir.

Claims (7)

1. In a capillary writing pen of the type including an ink reservoir communicating axially with a capillary writing tube at one end, and including a weight supported in the reservoir with cleaning wire extending from the weight into the capillary writing tube, the improvement comprising: A. a radially inwardly extending frustum having the large diameter thereof communicAting with said reservoir and the small diameter thereof communicating with said capillary tube; B. said frustum being inclined forwardly and inwardly towards said writing tube and in the direction of ink flow; C. said frustum being defined by a plurality of spaced ribs extending substantially longitudinally and inwardly angled increasingly towards said writing tube; D. said ribs defining therebetween capillary grooves communicating with said reservoir and said writing tube with said grooves extending radially inwardly from the periphery of said frustum to the axis of said writing tube; and E. the inner ends of said capillary grooves each defining a longitudinally extending feeding aperture spaced about the periphery of said writing tube.

2. A capillary writing pen as in claim 1, including at least one longitudinally extending groove defined in the wall of said reservoir and communicating at its forward end with at least one of said radially spaced grooves in said frustum.

3. A capillary writing pen as in claim 2, said longitudinally spaced groove being V-shaped notched in cross section.

4. A capillary writing pen as in claim 2, said longitudinally extending groove and said radially spaced groove both being similarly notched in cross section, so as to define a continued notched capillary groove extending from the sides of said reservoir, through said frustum and into the writing tube axis.

5. A capillary writing pen as in claim 4, said frustum including a peripheral outer shoulder at the juncture with said reservoir and said longitudinally extending grooves and said radially spaced grooves registering through said shoulder.

6. A capillary writing pen as in claim 1, wherein said weight defines a relatively small annulus for ink flow adjacent the inner wall of said reservoir.

7. A capillary writing pen as in claim 1, wherein said weight outer diameter is less than the diameter of said frustum at the juncture with said reservoir.

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