GB2150506A

GB2150506A - Writing implement

Info

Publication number: GB2150506A
Application number: GB08429961A
Authority: GB
Inventors: Hans Georg Henning
Original assignee: Vermes Chemie Co KG GmbH
Current assignee: Vermes Chemie Co KG GmbH
Priority date: 1983-11-28
Filing date: 1984-11-28
Publication date: 1985-07-03
Also published as: DE3343004A1; GB8429961D0; FR2555514A1; DE3343004C2; GB2150506B; JPS60135297A

Abstract

A writing implement has an ink container 2, a writing tip 6 fitted thereto and provided with an axial channel 4, and a capillary filament 8 of wear-resistant material mounted in the ink container 2 and projecting out of the axial channel 4 of the writing tip 6. The capillary filament 8 is straight and is formed in one piece to be self-supporting and laterally resiliently flexible, the outer diameter of the filament being slightly smaller than the diameter of the axial channel. The filament 8 includes radially open capillaries extending longitudinally and its internal end is supported in the ink container 2 against an abutment 12. <IMAGE>

Description

SPECIFICATION Writing implement The invention relates to a writing implement.

Writing implements are known which comprise an ink container, a writing tip fitted thereto and provided with an axial channel, and which include a straight capillary filament mounted in the ink con tanner and projecting out of the axial channel of the writing tip. Writing implements of this kind are used particularly in plotters.

It is desirable to provide a writing implement of this kind which produces clean strokes even when writing at high speed and when lifted frequently from the writing surface.

According to the invention there is provided a writing implement comprising an ink container, a writing tip fitted thereto and provided with an axial channel, a straight capillary filament mounted in the ink container and projecting out of the axial channel of the writing tip, the internal end of said capillary filament being supported in the ink container against an abutment, wherein the capillary filament is axially movable in the axial channel and is formed in one piece of a wear-resistant material to be selfsupporting and laterally resiliently flexible, having an external diameter slightly smaller than the diameter of the axial channel and having radially open capillaries extending in its longitudinal direction.

At least in a preferred embodiment of the invention, when the writing implement is applied to a writing surface, the capillary filament in the ink container is laterally deflected to some extent so that it presses resiliently on the writing surface. The capillaries in the filament ensure a uniform flow of ink, even with a certain pumping action, when the distance of the writing tip from the writing surface changes during writing.

Preferably, the writing tip of the implement comprises a tube passing through an end wall of the ink container and projecting slightly into the ink container. This ensures that the capillary filament is guided over a certain length as it leaves the writing tip.

The above-mentioned pumping action may be increased if the radially open capillaries extend helically about the longitudinal axis of the capillary filament.

Preferably, the ink container contains a store of filaments enclosing the internal end of the capillary filament, said filaments having a lower capillarity than the capillary filament. This provides a particularly uniform ink supply and the filament store also presents a certain resilient recoil force to counter the deflection of the capillary filament.

Preferably the capillary filament projects 0.1 to 1.0 mm out of the writing tip in the rest position, and the free end of the writing tip preferably has an external diameter of 0.2 to 1.2 mm.

It is preferred that 20 to 80% of the total length of the capillary filament is enclosed by the store of filaments. Preferably, the capillary filament has a diameter of from 0.1 to 1.0 mm and its capillaries are from 0.001 to 0.04 mm wide.

Preferably the writing tip has a compressive reaction force during writing of from 0.01 to 1 N.

An embodiment ofthe invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a longitudinal section through a writing implement in accordance with the invention; Figure 2 shows a cross section through a capillary filament.

The implement according to Figure 1 comprises an ink container 2 and a writing tip 6 fitted on the ink container 2 and provided with an axial channel 4.

Mounted in the ink container 2 is a capillary filament 8 of wear-resistant material which projects out of the axial channel 4 of the writing tip 6. The capillary filament 8 is straight in the rest position, and is formed in one piece from a material which is sufficiently inherently stiff for the filament 8 to be self-supporting, and which is sufficiently flexible for the filament 8 to be laterally resiliently bendable e.g.

by extrusion from polyacetal. Thus when the outer end of the self-supporting filament 8 is pressed against the writing surface and deflects axially, the portion of the filament within the ink container 2 flexes into a laterally deflected, or bent, condition.

The capillary filament 8 has an external diameter which is slightly smaller than the diameter of the axial channel 4, so that it can easily be moved longitudinally in the axial channel 4. Radially open capillaries 10 extend in the longitudinal direction of the capillary filament 8. The internal end of the capillary filament is supported in the ink container 2 against an abutment 12 which is formed, in this instance, by an end cover of the ink container 2.

The writing tip 6 is formed by a tube passing through the end wall 14 of the ink container 2, the rear or internal end of the tube projecting slightly into the ink container 2.

By torsion and subsequent fixing of the capillary filament, the capillaries 10 can be made to extend helically about the longitudinal axis of the capillary filament 8.

In the ink container 2 there is a store of filaments 16 enclosing the internal end of the capillary filament 8 and having a lower capillarity than the capillary filament 8.

The guide tube 6 consists of metal or some other resistant material with good sliding properties.

The cross section of the capillary filament 8 and hence of the channel 4 is preferably circular.

The front end of the writing tip 6 is preferably chamfered and smoothed so that it can slide perfectly over a writing surface.

1. A writing implement comprising an ink container, a writing tip fitted thereto and provided with an axial channel, a straight capillary filament mounted in the ink container and projecting out of the axial channel of the writing tip, the internal end of said capillary filament being supported in the ink container against an abutment, wherein the capillary filament is axially movable in the axial channel and is formed in one piece of a wear-resistant material to be self-supporting and laterally resiliently flexible,

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Writing implement The invention relates to a writing implement. Writing implements are known which comprise an ink container, a writing tip fitted thereto and provided with an axial channel, and which include a straight capillary filament mounted in the ink con tanner and projecting out of the axial channel of the writing tip. Writing implements of this kind are used particularly in plotters. It is desirable to provide a writing implement of this kind which produces clean strokes even when writing at high speed and when lifted frequently from the writing surface. According to the invention there is provided a writing implement comprising an ink container, a writing tip fitted thereto and provided with an axial channel, a straight capillary filament mounted in the ink container and projecting out of the axial channel of the writing tip, the internal end of said capillary filament being supported in the ink container against an abutment, wherein the capillary filament is axially movable in the axial channel and is formed in one piece of a wear-resistant material to be selfsupporting and laterally resiliently flexible, having an external diameter slightly smaller than the diameter of the axial channel and having radially open capillaries extending in its longitudinal direction. At least in a preferred embodiment of the invention, when the writing implement is applied to a writing surface, the capillary filament in the ink container is laterally deflected to some extent so that it presses resiliently on the writing surface. The capillaries in the filament ensure a uniform flow of ink, even with a certain pumping action, when the distance of the writing tip from the writing surface changes during writing. Preferably, the writing tip of the implement comprises a tube passing through an end wall of the ink container and projecting slightly into the ink container. This ensures that the capillary filament is guided over a certain length as it leaves the writing tip. The above-mentioned pumping action may be increased if the radially open capillaries extend helically about the longitudinal axis of the capillary filament. Preferably, the ink container contains a store of filaments enclosing the internal end of the capillary filament, said filaments having a lower capillarity than the capillary filament. This provides a particularly uniform ink supply and the filament store also presents a certain resilient recoil force to counter the deflection of the capillary filament. Preferably the capillary filament projects 0.1 to 1.0 mm out of the writing tip in the rest position, and the free end of the writing tip preferably has an external diameter of 0.2 to 1.2 mm. It is preferred that 20 to 80% of the total length of the capillary filament is enclosed by the store of filaments. Preferably, the capillary filament has a diameter of from 0.1 to 1.0 mm and its capillaries are from 0.001 to 0.04 mm wide. Preferably the writing tip has a compressive reaction force during writing of from 0.01 to 1 N. An embodiment ofthe invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a longitudinal section through a writing implement in accordance with the invention; Figure 2 shows a cross section through a capillary filament. The implement according to Figure 1 comprises an ink container 2 and a writing tip 6 fitted on the ink container 2 and provided with an axial channel 4. Mounted in the ink container 2 is a capillary filament 8 of wear-resistant material which projects out of the axial channel 4 of the writing tip 6. The capillary filament 8 is straight in the rest position, and is formed in one piece from a material which is sufficiently inherently stiff for the filament 8 to be self-supporting, and which is sufficiently flexible for the filament 8 to be laterally resiliently bendable e.g. by extrusion from polyacetal. Thus when the outer end of the self-supporting filament 8 is pressed against the writing surface and deflects axially, the portion of the filament within the ink container 2 flexes into a laterally deflected, or bent, condition. The capillary filament 8 has an external diameter which is slightly smaller than the diameter of the axial channel 4, so that it can easily be moved longitudinally in the axial channel 4. Radially open capillaries 10 extend in the longitudinal direction of the capillary filament 8. The internal end of the capillary filament is supported in the ink container 2 against an abutment 12 which is formed, in this instance, by an end cover of the ink container 2. The writing tip 6 is formed by a tube passing through the end wall 14 of the ink container 2, the rear or internal end of the tube projecting slightly into the ink container 2. By torsion and subsequent fixing of the capillary filament, the capillaries 10 can be made to extend helically about the longitudinal axis of the capillary filament 8. In the ink container 2 there is a store of filaments 16 enclosing the internal end of the capillary filament 8 and having a lower capillarity than the capillary filament 8. The guide tube 6 consists of metal or some other resistant material with good sliding properties. The cross section of the capillary filament 8 and hence of the channel 4 is preferably circular. The front end of the writing tip 6 is preferably chamfered and smoothed so that it can slide perfectly over a writing surface. CLAIMS

1. A writing implement comprising an ink container, a writing tip fitted thereto and provided with an axial channel, a straight capillary filament mounted in the ink container and projecting out of the axial channel of the writing tip, the internal end of said capillary filament being supported in the ink container against an abutment, wherein the capillary filament is axially movable in the axial channel and is formed in one piece of a wear-resistant material to be self-supporting and laterally resiliently flexible, having an external diameter slightly smallerthan the diameter of the axial channel and having radially open capillaries extending in its longitudinal direction.

2. An implement as claimed in claim 1, wherein the writing tip comprises a tube passing through an end wall of the ink container and projecting slightly into the ink container.

3. An implement as claimed in claim 1 or2, wherein said capillaries extend helically about the longitudinal axis of the capillary filament.

4. An implement as claimed in claim 1,2 or 3, wherein the ink container contains a store offilaments enclosing the internal end of the capillary filament, said filaments having a lower capillarity than the capillary filament.

5. An implement as claimed in any of the preceding claims, wherein the capillary filament projects 0.1 to 1.0 mm out of the writing tip in the rest position.

6. An implement as claimed in any of the preceding claims, wherein the free end of the writing tip has an external diameter of 0.2 to 1.2 mm.

7. An implement as claimed in any of the preceding claims, wherein 20 to 80% of the total length of the capillary filament is enclosed by the store of filaments.

8. An implement as claimed in any of the preceding claims, wherein the writing tip has a compressive reaction force during writing of from 0.01 to 1 N.

9. An implement as claimed in any of the preceding claims, wherein the capillary filament has a diameter of from 0.1 to 1.0 mm and its capillaries are from 0.001 to 0.04 mm wide.

10. A writing implement substantially as hereinbefore described with reference to the accompanying drawings.