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EP-4741175-A1 - WRITING INSTRUMENT, IN PARTICULAR REFILLABLE WRITING INSTRUMENT

EP4741175A1EP 4741175 A1EP4741175 A1EP 4741175A1EP-4741175-A1

Abstract

The invention relates to a writing instrument (100), in particular refillable writing instrument, comprising - a shaft (10) extending in a longitudinal direction (L), - a cartridge (11) configured to provide a reservoir (12) for application liquid, wherein the cartridge (11) is arranged within the shaft (10)in a rear section, wherein a receiving section (14) is provided at a front end of the cartridge (11), - a capillary application element (16) being arranged at a front end of the shaft (10), - an adapter (18) configured to be arranged within the receiving section (14) of the cartridge (11), wherein the adapter (18, 18') is configured to fluidly connect the application element (16) with the reservoir (12) via a through-channel (20, 20') extending in the longitudinal direction (L), and wherein the through-channel (20, 20') comprises an inner section (20c, 20c') and at least two outer sections (20a, 20a', 20b, 20b'), wherein the at least two outer sections (20a, 20a', 20b, 20b') are fluidly connected via the inner section (20c, 20c') in the longitudinal direction (L) at least in sections and wherein the inner section (20c, 20c') forms a narrower passage than the outer sections (20a, 20a', 20b, 20b') so that a flow rate between the reservoir (12) and the application element (16) through an outer section (20a, 20a, 20b, 20b') is larger than a flow rate between the reservoir (12) and the application element (16) through the inner section (20c, 20c').

Inventors

  • Loh, Wen Cheun

Assignees

  • Faber- Castell AG

Dates

Publication Date
20260513
Application Date
20241128

Claims (15)

  1. Writing instrument (100, 100'), in particular refillable writing instrument, comprising - a shaft (10) extending in a longitudinal direction (L), - a cartridge (11) configured to provide a reservoir (12) for application liquid, wherein the cartridge (11) is arranged within the shaft (10)in a rear section, wherein a receiving section (14) is provided at a front end of the cartridge (11), - a capillary application element (16) being arranged at a front end of the shaft (10), - an adapter (18) configured to be arranged within the receiving section (14) of the cartridge (11), wherein the adapter (18, 18') is configured to fluidly connect the application element (16) with the reservoir (12) via a through-channel (20, 20') extending in the longitudinal direction (L), and wherein the through-channel (20, 20') comprises an inner section (20c, 20c') and at least two outer sections (20a, 20a', 20b, 20b'), wherein the at least two outer sections (20a, 20a', 20b, 20b') are fluidly connected via the inner section (20c, 20c') in the longitudinal direction (L) at least in sections and wherein the inner section (20c, 20c') forms a narrower passage than the outer sections (20a, 20a', 20b, 20b') so that a flow rate between the reservoir (12) and the application element (16) through an outer section (20a, 20a, 20b, 20b') is larger than a flow rate between the reservoir (12) and the application element (16) through the inner section (20c, 20c').
  2. Writing instrument (100, 100') according to claim 1, characterised in that, the inner section (20c, 20c') and the outer sections (20a, 20a', 20b, 20b') have different dimensions in the longitudinal direction (L), in particular a different length, and/or different dimensions in a plane perpendicular to said longitudinal direction (L), in particular different cross-sections and/or shape.
  3. Writing instrument (100, 100') according to any of the claims 1 or 2, characterised in that, the at least two outer sections (20a, 20a', 20b, 20b') have the same dimensions in the longitudinal direction (L), in particular the same length, and/or the same dimensions in a plane perpendicular to said longitudinal direction (L), in particular the same cross-sections and/or shape.
  4. Writing instrument (100, 100') according to any of the preceding claims, characterised in that, the inner section (20c) has a rectangular cross-section in a plane perpendicular to said longitudinal direction (L) with a length being many times greater than a width and/or the outer sections (20a, 20a', 20b, 20b') have a round, semicircular, circular or elliptical cross-section in a plane perpendicular to said longitudinal direction (L).
  5. Writing instrument (100, 100') according to any of the preceding claims, characterised in that, the adapter (18, 18') comprises a rear wall (18a) or a rear section (18d'), an outer wall (18b, 18b') and an inner wall (18c, 18c'), wherein the outer wall (18b, 18b') and the inner wall (18c, 18c') extend from the rear wall (18a) or the rear section (18a') in the longitudinal direction (L) and are spaced apart from each other in a radial direction (R).
  6. Writing instrument (100, 100') according to claim 5, characterised in that, the through-channel (20, 20'), in particular the inner section (20c, 20c') and the outer sections (20a, 20a', 20b, 20b'), is formed by the inner wall (18c, 18c') of the adapter (18, 18'), the inner wall (18c, 18c') extending further from the rear wall (18a) or the rear section (18d') in the longitudinal direction (L) than the outer wall (18b, 18b').
  7. Writing instrument (100, 100') according to any of the preceding claims, characterised in that, the outer sections (20a, 20a', 20b, 20b') extend beyond the inner section (20c, 20c') in the longitudinal direction (L), wherein the outer sections (20a', 20b') have a tubular shape and are surrounded completely by the inner wall (18c') at least in the section extending beyond the inner section (20c').
  8. Writing instrument (100, 100') according to any of the claim 6 to 7, characterised in that, the rear wall (18a) and/or rear section (18a') and/or outer wall (18b, 18b') abut on an inner surface (14b) of the receiving section (14) in a sealing manner and/or the outer wall (18b, 18b') overlaps a front end (14a) of the receiving section (14) at least partially in a radial direction (R) and abuts on the front end (14a) of the receiving section (14) in a sealing manner.
  9. Writing instrument (100, 100') according to any of the claims 6 to 8, characterised in that, the outer wall (18b, 18b') at least partially abuts on an inner surface (30) of the shaft (10) in a sealing manner and/or by forming a positive fit effective in the longitudinal direction (L).
  10. Writing instrument (100, 100') according to any of the preceding claims, characterised in that, the writing instrument (100) further comprises a filter element (24) being arranged within the shaft (10) and between the adapter (18, 18'), in particular the trough-channel (20, 20') of the adapter (18, 18'), and the application element (16), wherein the filter element (24) is configured to fluidly connect the application element (16) with the through-channel (20, 20') and the reservoir (12).
  11. Writing instrument (100, 100') according to claim 10, characterised in that, a recess (22) is provided at a front surface of the inner wall (18a, 18a') in the area of the inner section (20c, 20c') configured to receive the filter element (24).
  12. Writing instrument (100, 100') according to any of the claims 10 to 11, characterised in that, the filter element (24) at least partially abuts on an inner surface of the shaft (10), in particular forming a positive fit effective in the longitudinal direction (L).
  13. Writing instrument (100, 100') according any of claims 10 to 12, characterised in that, the filter element (24) is made of fibres extending in the longitudinal direction (L), wherein the filter element (24) comprises a front section and a rear section and wherein the fibres are compressed in the front section so that the fibres are arranged in a more dense state in the front section than in the rear section.
  14. Writing instrument (100, 100') according to any of the claims 10 to 13, characterised in that, a first air space (26, 26') is provided between the application element (16), the filter element (24) and the shaft (10) said air space (26, 26') being configured to receive air passing past the application element (16) from outside during the use of the writing instrument (100, 100') to equalize pressure inside the writing instrument (100, 100') and a second air space (34) is provided within the cartridge (11) to receive air from the first air space (26, 26') through the through-channel (20, 20') during the use of the writing instrument (100, 100') to equalize pressure inside the writing instrument (100, 100').
  15. Writing instrument (100, 100') according to any of the claims 10 to 14, characterised in that, a volume in the first air space (26, 26') is smaller than a volume in the second air space (34) and/or a pressure in the first air space (26, 26') is larger than a pressure in the second air space (34).

Description

The present invention relates to a writing instrument, in particular a refillable writing instrument. Known writing instruments, in particular refillable writing instruments, such as cartridge markers have cartridges providing a reservoir for an application liquid (or: ink) and an application element, in particular a capillary application element. The application element is fluidly connected to said reservoir and configured to transfer application liquid onto a writing medium when the writing instrument is used. Refillable cartridge markers (RCM) work on the principle of ink surface tension, air displacement, suffocation of airflow by saturated ink in a filter element and pressure equalization between chambers that are present within the marker. Known cartridge markers have the disadvantage that the application liquid, which is flowing free in the reservoir, will continue flowing when the writing instrument is held in a vertical position, thus when the tip of the application element is directed downwardly in a vertical direction. A filter element may be arranged between the reservoir and the application element for regulating the flow of application liquid, in particular to reduce flow towards the application element and prevent leakage of the application liquid. Nevertheless, such a system needs to have good hermetic sealing to prevent tip bleeding during external or internal pressure change. The ink flow control is critical to the ink lay down, ink intensity and writing length, while the hermetic sealing is crucial to prevent ink bleeding through the tip of the application element and leaking of ink at joining parts of the components of the writing instrument. It is therefore an object of the present invention to provide a writing instrument, in particular a refillable writing instrument such as a refillable cartridge marker that is improved with regard to control of the flow of an application liquid and hermetic sealing. This object is solved by a writing instrument, in particular a refillable writing instrument, more particularly a refillable cartridge marker, according to claim 1. The writing instrument comprises a shaft extending in a longitudinal direction and a cartridge configured to provide a reservoir for application liquid (or: ink), wherein the cartridge is at least partially, preferably completely arranged within the shaft. In other words: The cartridge contains an application liquid (or: ink) and/or is configured to receive and/or store an application liquid. A receiving section is provided at a front end of the cartridge, configured to receive a further component of the writing instrument in a sealing manner. The writing instrument further comprises a capillary application element (or: nib) for transferring application liquid onto a writing medium such as paper. The application element is arranged at a front end of the shaft and is fluidly connected to said reservoir for receiving application liquid therefrom. An adapter (or: connecting piece) is configured to be arranged within the receiving section of the cartridge provided at the front end of the cartridge. The adapter comprises a through-channel that extends in the longitudinal direction and is configured to fluidly connect the application element - directly or indirectly - with the reservoir. The through-channel comprises - relative to a radial direction - an inner section and at least two outer sections, each of them extending in the longitudinal direction, wherein the at least two outer sections are fluidly connected via the inner section in the longitudinal direction at least in sections and wherein the outer sections and the inner section are designed such that a flow rate of application liquid and/or air between the reservoir and the application element through an outer section is larger than a flow rate of application liquid and/or air between the reservoir and the application element through the inner section. In other words: The inner section forms a narrower passage than the outer sections so that a flow rate of application liquid and/or air between the reservoir and the application element through an outer section is larger than a flow rate of application liquid and/or air between the reservoir and the application element through the inner section. More particularly, the through-channel is a single channel, but comprises an inner section extending in the longitudinal direction and at least two outer sections extending in the longitudinal direction, wherein these sections have such a cross-section or shape that application liquid and/or air merely flow through the outer sections, but only very minimal through the inner section. In other words, the inner section and the outer sections each extend at least essentially parallel to each other in the longitudinal direction and are fluidly connected to form one single channel through which the application liquid and/or air can flow through. As the inner and outer sections are fluidly