An erasable ink writing instrument comprising a body extending along an axis, the body having a first end and a second end opposed to the first end along the axis, the first end being provided with a writing tip and with an eraser, wherein the writing tip is fed with erasable ink, wherein the writing tip is fixed with regard to the body and the eraser is movable along the axis with regard to the body, and the erasable ink writing instrument further comprising a helical-cam propelling mechanism configured to move the eraser along the axis between a retracted position and a protruding position. The erasable ink is a peelable ink and the eraser is a friction body.

A writing instrument has a gripping tube rotatably fitted on a front portion of a barrel. At the front portion of the barrel, plural identifying marks having different identification characteristics, such as color, are disposed in parallel in a circumferential direction of the barrel. A window portion is provided in the gripping tube through which is visible an identifying mark selected by rotating the gripping tube relative to the barrel. When the user rotates the gripping tube to the position where the chosen color is visible through the window portion, a locking pawl on the barrel engages with a locking groove at the rear end of the gripping tube to lock the gripping tube in this position. Once locked in position, the gripping tube cannot accidentally rotate thereby preventing a change of colors appearing at the window portion even if the writing instrument is subjected to shock or vibration.

A thermochromic writing instrument including a writing body, storing a thermochromic ink therein, stored in a barrel; an operation body provided in the barrel to be operated to longitudinally move the writing body; a nib of the writing body configured to be capable of appearing from a front end of the writing instrument, wherein the writing instrument 1 further includes a friction unit, for rubbing handwriting in the thermochromic ink and capable of thermally changing the color of the handwriting by frictional heat generated at that time, and at least one clip body as the operation body, the friction unit 10 is provided at a rear end of the barrel, and the clip body is provided in an area other than the rear end of the barrel.

A knock type writing tool is provided, in which an appropriate amount of air can be taken in depending on an amount of a thermochromic ink discharged from a pen tip, so that the thermochromic ink can be smoothly discharged from the pen tip, and in which a writing body can rotate surely in conjunction with a rotation of a rotating member. An air hole 63a and a plurality of projection pieces 63b are provided at a rear end portion of a writing body 6. A front surface of a projection and retraction rotating member 7 is provided with a plurality of abutment parts 73, on which respective rear ends of the plurality of projection pieces 63b are to abut, and with a plurality of protrusion parts 72, each of which is formed between the plurality of abutment parts 73 and protruded more forward than the plurality of abutment parts 73. The protrusion parts 72 are respectively inserted in gaps 63c between the projection pieces 63b. An axial length of each projection piece 63b is longer than an axial length of each protrusion part 72, so that a portion of the gap 63c is left more forward than a front end of each protrusion part 72.

A writing instrument, in particular a pen, comprises a housing comprising a front barrel and a rear barrel, the front barrel having a front opening, two or more cartridges for storing colorants or inks, each cartridge having a writing tip, at least one actuator for selectively moving one of the cartridges within the housing so that the writing tip of a selected cartridge extends through the front opening of the front barrel, and a cartridge guide member which is designed to guide the movement of the cartridges within the housing. The front barrel and the cartridge guide member are designed to be removed from the rear barrel for replacing one or more of the cartridges. In particular, the front barrel and the cartridge guide member may be removed from the rear barrel while the cartridge guide member may remain mounted to the front member at the same time.

The adaptation of a pocket-size pen for use by a person is provided. The pen includes a cap with internally configured male threads, and a body. The body includes a barrel with externally configured and spaced apart first set of female threads, and second set of female threads. The barrel is hollow inside with a top opening for receiving a full-sized standard ink source. The male threads of the cap engage the second set of female threads of the pen body for closing a writing tip and reducing the length of the pen for storage in the pocket of a user. The male threads of the cap engage the first set of female threads of the body for transforming the pen into an extended-length pen similar in length to a conventional pen and revealing the writing tip for comfortable writing using the pen.

A retractive writing utensil includes a shaft tube, a core stored in the shaft tube in such a manner as to protrude from a front end of the shaft tube when moved forward, and an urging member that is stretched and contracted in the shaft tube in a front-rear direction, wherein the urging member is located adjacent to the core radially outward in such a manner that the center of the urging member is positioned radially outside the core, and urges the core rearward.

A pen comprising a shaft, a gripping zone, and a measuring device having a sensor configured to measure a force acting on the gripping zone. The pen further comprises a cover in the area of the gripping zone, the cover configured to cover the measuring device.

The present invention provides a thermochromic color-memory composition including (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) an ester compound represented by the following formula (1) or (2), as a reaction medium which controls color reaction of the component (a) and the component (b); and a thermochromic color-memory microcapsule pigment encapsulating the thermochromic color-memory composition. ##STR00001##

A writing instrument includes a body, a nosecone, and an adaptor each being of generally hollow tubular shape. The body, the nosecone, and the adaptor each have a first end and a second end. The first end of the adaptor is configured to slidably couple to the nosecone second end. The second end of the adaptor is coupled to the first end of the body. The writing instrument includes a writing element with a mounting end and a writing end where the mounting end is removably coupled to the second end of the body. The writing instrument includes a locking mechanism configured to selectively lock the nosecone in a storage position or a writing position. In the storage position, the nosecone extends and covers the writing end. In the writing position, the nosecone retracts and the writing end of the writing element extends beyond the nosecone.