Disclosed is a direct-liquid writing instrument. Two ends of a penholder (1) are provided with a writing portion (11) and an ink storage portion (12) respectively. A nib (3) is partly inserted into the writing portion (11). A first baffle (41) and a second baffle (42) of an adjusting portion (4) are spaced apart so that an air barrier layer (43) is formed between the two baffles. The first baffle (41) is in contact with the ink (13) of the ink storage portion (12). The second baffle (42) is adjacent to the writing portion (11). An ink feeder (2) passes through the first baffle (41), the air barrier layer (43) and the second baffle (42). The first baffle (41) is provided with a first air-guiding channel (8). A second air-guiding channel (7) is provided between the second baffle (42) and the ink feeder (2). At least one gap is formed between the second air-guiding channel (7) and the ink feeder (2). The present direct-liquid writing instrument has the advantages as follows: 1) a large storage capacity, low ink residuals, and fluency in writing; 2) prevention to leakage even under significant variation of external temperature and pressure; 3) simple and stable in structure, resistant to pressure difference and temperature difference, and convenient for transportation; 4) high ink utilization rate, convenient for usage, and less waste and environment pollution.

Disclosed is a direct-liquid writing instrument. Two ends of a penholder (1) are provided with a writing portion (11) and an ink storage portion (12) respectively. A nib (3) is partly inserted into the writing portion (11). A first baffle (41) and a second baffle (42) of an adjusting portion (4) are spaced apart so that an air barrier layer (43) is formed between the two baffles. The first baffle (41) is in contact with the ink (13) of the ink storage portion (12). The second baffle (42) is adjacent to the writing portion (11). An ink feeder (2) passes through the first baffle (41), the air barrier layer (43) and the second baffle (42). The first baffle (41) is provided with a first air-guiding channel (8). A second air-guiding channel (7) is provided between the second baffle (42) and the ink feeder (2). At least one gap is formed between the second air-guiding channel (7) and the ink feeder (2). The present direct-liquid writing instrument has the advantages as follows: 1) a large storage capacity, low ink residuals, and fluency in writing; 2) prevention to leakage even under significant variation of external temperature and pressure; 3) simple and stable in structure, resistant to pressure difference and temperature difference, and convenient for transportation; 4) high ink utilization rate, convenient for usage, and less waste and environment pollution.

The present disclosure described herein, in general, describes a refillable writing instrument. The writing instrument may comprise one or more master reservoir, one or more slave reservoir, one or more slave reservoir gate and one or more master reservoir gate. The slave reservoir may have reducing cross-section, facilitating fluid flow towards nib of the writing instrument. The slave reservoir gate may comprise at least one of blocking element, blocking element seat, one or more gates, one or more covers and a combination thereof. The slave reservoir gate provides a connection between the master reservoir and the slave reservoir. Further, the blocking element rests over the blocking element seat due to gravity, restricting return flow of the fluid to the master reservoir. The master reservoir gate facilitates clean, easy and fast refilling of master reservoir using fluid container or fluid nozzle without the need of opening the master reservoir cap.

The present disclosure described herein, in general, describes a refillable writing instrument. The writing instrument may comprise one or more master reservoir, one or more slave reservoir, one or more slave reservoir gate and one or more master reservoir gate. The slave reservoir may have reducing cross-section, facilitating fluid flow towards nib of the writing instrument. The slave reservoir gate may comprise at least one of blocking element, blocking element seat, one or more gates, one or more covers and a combination thereof. The slave reservoir gate provides a connection between the master reservoir and the slave reservoir. Further, the blocking element rests over the blocking element seat due to gravity, restricting return flow of the fluid to the master reservoir. The master reservoir gate facilitates clean, easy and fast refilling of master reservoir using fluid container or fluid nozzle without the need of opening the master reservoir cap.

The subject disclosure relates to systems, methods, and apparatuses that perform self-erasing writings. In an aspect, the subject disclosure includes deploying a self-erasing material, onto a writing medium, from an apparatus comprising a tip element and a body element. In another aspect, the method includes removal of the self-erasing material on a time-released schedule based on an interaction between a set of environmental conditions and the self-erasing material.

A double-head marker pen includes a first penholder, a second penholder and a connecting tube; one end of the first penholder is formed with a first pen head, and one end of the second penholder is formed with a second pen head; and an end of the first penholder away from the first pen head is detachably connected with an end of the second penholder away from the second pen head by the connecting tube.

A double-head marker pen includes a first penholder, a second penholder and a connecting tube; one end of the first penholder is formed with a first pen head, and one end of the second penholder is formed with a second pen head; and an end of the first penholder away from the first pen head is detachably connected with an end of the second penholder away from the second pen head by the connecting tube.

A compensation membrane for compensating a pressure difference between the outside and the inside of a free ink reservoir of a pen or the equivalent, the membrane comprising a first portion having a first rigidity, and a second portion having a second rigidity, the first rigidity being less than the second rigidity. A pen or the equivalent comprising a free ink reservoir provided with such a compensation membrane.

A compensation membrane for compensating a pressure difference between the outside and the inside of a free ink reservoir of a pen or the equivalent, the membrane comprising a first portion having a first rigidity, and a second portion having a second rigidity, the first rigidity being less than the second rigidity. A pen or the equivalent comprising a free ink reservoir provided with such a compensation membrane.

A marking instrument having a plurality of removable writing nibs serially aligned so that an operator can remove a spent or fluid-affected writing nib and, thereby, access a fresh writing tip.