Writing instrument

Abstract

A thermochromic 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 thermochromic 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 thermochromic 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.

Claims

1. A thermochromic 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 thermochromic 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 thermochromic 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, wherein the helical-cam propelling mechanism includes a first part and a second part, the body comprises a first portion having the first end and a second portion having the second end, the first portion and the second portion are rotatable relative to each other, and the first part is rotatably coupled with the first portion and axially movable with regard to the first portion.

2. The thermochromic ink writing instrument according to claim 1, wherein the eraser and the writing tip are coaxial, the eraser being disposed around the writing tip, the writing tip comprising a writing end, and, when the thermochromic ink writing instrument is seen perpendicular to the axis, the writing end is concealed by the eraser when the eraser is in the protruding position and the writing end is free from the eraser when the eraser is in the retracted position.

3. The thermochromic ink writing instrument according to claim 1, wherein the first part includes one of a helical cam and a cam follower and the second part includes the other of the helical cam and the cam follower, and the first part is axially coupled in at least one direction with the eraser and the second part is fixed to the second end, inside the body.

4. The thermochromic ink writing instrument according to claim 1, wherein the second part is snap-fitted with the second end.

5. The thermochromic ink writing instrument according to claim 1, wherein the first part comprises one of at least one axial projection and at least one axial recess, the first portion comprises the other of the at least one axial projection and the at least one axial recess, and the at least one axial projection and the at least one axial recess are slidably engaged with each other axially.

6. The thermochromic ink writing instrument according to claim 1, comprising a writing body having the writing tip, wherein the eraser is mounted onto a tube holder, the eraser is axially coupled in at least one direction with the first part via the tube holder, and the writing body extends at least in part into the tube holder in any position of the eraser.

7. The thermochromic ink writing instrument according to claim 1, comprising a writing body having the writing tip, wherein the body comprises a nose cone, the nose cone comprises the first end, and the nose cone is removable, due to which the writing body is removable for refill.

8. The thermochromic ink writing instrument according to claim 1, wherein the eraser is mounted onto a tube holder, a rear portion of the eraser being configured to be fitted within a front end of the tube holder.

9. The thermochromic ink writing instrument according to claim 1, comprising a return spring configured to axially push the eraser toward the first part.

10. The thermochromic ink writing instrument according to claim 9, wherein the return spring is configured to axially push the eraser from the extended position toward the retracted position while the eraser abuts against the first part axially.

11. The thermochromic ink writing instrument according to claim 1, comprising a writing body having the writing tip, wherein the first part is hollow, a support extends inside the first part and is axially coupled with the second part, and the support supports the writing body.

12. The thermochromic ink writing instrument according to claim 11, wherein the writing body is removably mounted to the support.

13. The thermochromic ink writing instrument according to claim 11, wherein the writing body is press-fitted to the support.

14. The thermochromic ink writing instrument according to claim 11, wherein the support and the second part are unitarily formed.

15. The thermochromic ink writing instrument according to claim 1, wherein the eraser is a body configured to be rubbed over a surface to generate heat thereby causing the thermochromic ink to change color.

16. The thermochromic ink writing instrument according to claim 15, wherein the eraser is a friction body, and the eraser is made of rubber or elastomer.

17. The thermochromic ink writing instrument according to claim 15, wherein the eraser is made of styrene-ethylene-butylene-styrene copolymer (SEBS), styrene-butadiene-styrene copolymer (SBS), ethylene-propylene-diene monomer (EPDM).

18. The thermochromic ink writing instrument according to claim 15, wherein the eraser has a friction coefficient ranging from 0.2 to 1.0 when rubbed against a paper surface.

19. A thermochromic 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 thermochromic 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 thermochromic ink writing instrument further comprises a helical-cam propelling mechanism configured to move the eraser along the axis between a retracted position and a protruding position, wherein the helical-cam propelling mechanism includes a first part and a second part, and wherein the thermochromic ink writing instrument further comprises a return spring configured to axially push the eraser toward the first part.

20. A thermochromic 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 thermochromic 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 thermochromic ink writing instrument further comprises a helical-cam propelling mechanism configured to move the eraser along the axis between a retracted position and a protruding position, wherein the helical-cam propelling mechanism includes a first part and a second part, wherein the thermochromic ink writing instrument further comprises a writing body having the writing tip, wherein the first part is hollow, a support extends inside the first part and is axially coupled with the second part, and the support supports and restricts a movement of the writing body.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Additional details and features of the disclosure are described with reference to the following figures in which

(2) FIG. 1 shows an erasable ink writing instrument;

(3) FIG. 2 shows an exploded view of the erasable ink writing instrument of FIG. 1;

(4) FIG. 3 shows a sectional view of the erasable ink writing instrument of FIG. 1, in the plane III of FIG. 1;

(5) FIG. 4 shows the erasable ink writing instrument seen perpendicular to the axis X, the eraser being in the retracted position;

(6) FIG. 5 shows the erasable ink writing instrument seen perpendicular to the axis X, the eraser being in an intermediate position between the retracted position and the protruding position;

(7) FIG. 6 shows the erasable ink writing instrument seen perpendicular to the axis X, the eraser being in the protruding position.

DETAILED DESCRIPTION

(8) FIGS. 1, 2 and 3 show an erasable ink writing instrument 10 comprising a body 12 extending along an axis X. The body 12 has a first end (or front end) 12A and a second end (or rear end) 12B opposed to the first end 12A along the axis X. The first end 12A is provided with a writing tip 14 and with an eraser 16. The writing tip 14 is fed with erasable ink. The writing tip 14 is fixed with regard to the body 12. The eraser 16 is movable along the axis X with regard to the body 12 (see double-arrow I in FIG. 1). The erasable ink writing instrument 10 further comprises a helical-cam propelling mechanism 18 (see FIGS. 2 and 3) configured to move the eraser 16 along the axis X between a retracted position (see FIGS. 1, 3 and 4) and a protruding position (see FIG. 5).

(9) The eraser 16 and the writing tip 14 may be coaxial. The eraser 16 may be disposed around the writing tip 14. The eraser 16 may form a sleeve extending along the axis X and configured to receive therein all or part of the writing tip 14. The writing tip 14 may comprise a writing end 14A. When the writing instrument 10 is seen perpendicular to the axis X as in FIGS. 4 to 6, the writing end 14A may be concealed by the eraser 16 when the eraser 16 is in the protruding position (see FIG. 6) and the writing end 14A may free from the eraser 16 when the eraser 16 is in the retracted position (see FIG. 4). When the writing instrument 10 is seen perpendicular to the axis X, the writing end 14A may be free from the eraser 16 when the eraser 16 is in an intermediate position between the protruding position and the retracted position (see FIG. 5). The eraser 16 may have a distal end 16A. The distal end may have a frustoconical shape. This may render the writing easier when the eraser 16 is in the intermediate position.

(10) eraser 16 may be mounted onto a tube holder 20. In this example, a rear portion 16B (i.e. a portion axially disposed on the side of the second end 12B) of the eraser 16 is press fitted within a front end 20A (i.e. an end axially disposed on the side of the first end 12A) of the tube holder 20.

(11) The helical-cam propelling mechanism 18 may comprise a first part 18A having in this example a helical cam 18A1 and a second part 18B having a cam follower 18B1. In this example, the first part 18A may have a single helical cam 18A1 and the second part 18B may have a single cam follower 18B1. As shown in the detailed view of FIG. 2, the cam follower 18B1 is engaged with the cam helical cam 18A1. In the present example, the angular stoke of the helical-cam propelling mechanism 18 may be up to 90°.

(12) The second part 18B may be fixed to the second end 12B, inside the body 12. In this example, the second part 18B may be snap-fitted to the second end 12B. The snap-fitted parts of the second part 18B and of the second end 12B may be configured to cooperate in form fitting manner in order to prevent relative rotation between the second part 18B and the second end 12B around the axis X. A snap-fitting rib 18B2 may be engaged with a snap-fitting groove 12B1 in order to axially couple the second part 18B and the second end 12B while a flat 18B3 of the second part 18B may cooperate in form fitting manner with a complementary flat (not shown) of the second end 12B in order to rotatably couple the second part 18B and the second end 12B around the axis X. In the present example, two flats 18B3 and two complementary flats may be provided. Any other shape may be provided.

(13) The body 12 may comprise a first portion 12-1 having the first end 12A and a second portion 12-2 having the second end 12B. The first portion 12-1 and the second portion 12-2 may be rotatable relative to each other. The first portion 12-1 and the second portion 12-2 may be rotatably snap-fitted. For example, the first portion 12-1 may have a snap-fitting annular rib 12-1a rotatably engaged with a complementary snap-fitting annular rib 12-2a of the second portion 12-2.

(14) The first part 18A may be rotatably coupled with the first portion 12-1 and axially movable with regard to the first portion 12-1. For example, the first part 18A may comprise two axial projections 18A2 and the first portion 12-1 may comprise two axial recesses 12-1b. The two axial projections 18A2 and the two axial recesses 12-1b may be slidably engaged with each other axially.

(15) In this example, the first part 18A may be hollow and may receive a rear end 20B of the tube holder 20. The first part 18A may be axially coupled in only a first direction X1 with the eraser 16, via the tube holder 20. In other words, the first part 18A may axially move the eraser 16 only when the first part 18A is moved in a first axial direction X1. The tube holder 20 may axially abut against the first part 18A. In other words, in this example the eraser 16 may abut axially against the first part 18A via the tube holder 20. When the first part 18A is moved in a second axial direction X2, opposite to the first axial direction X1, the first part 18A may be not able to move the eraser 16.

(16) A return spring 22 may be configured to axially push the eraser 16 toward the first part 18A. In this example, the return spring 22 may be configured to axially push the eraser 16 from the extended position toward the retracted position, in the second axial direction X2. The return spring 22 may be a coil spring which works in compression. As shown in FIGS. 4 to 6, a first end 22A of the return spring 22 may abut against a first shoulder 12C of the body 12 and a second end 22B, axially opposite to the first end 22A, may abut against a shoulder 16C of the eraser 16. In a variant not shown, the second end 22B may abut against a shoulder of the tube holder 20.

(17) Therefore, in the present example, when the second portion 12-2 of the body 12 is rotated relatively to the first portion 12-1 in the first rotational direction R1 around the axis X shown in FIG. 1, the second part 18B rotates together with the second portion 12-2 and pushes axially the first part 18A via the cam follower 18B1 and the helical cam 18A1 in the first axial direction X1, then pushing the eraser 16 in the first axial direction X1. The eraser 16 is thus moved from the retracted position (see FIG. 4) toward the intermediate and the protruding position (see FIGS. 5 and 6). No button may be needed in order to actuate the eraser 16. The writing instrument 10 may thus be a buttonless writing instrument. The structure of such a writing instrument may be simple and provide better ergonomics on the body.

(18) When the second portion 12-2 of the body 12 is rotated relatively to the first portion 12-1 in the second rotational direction R2, opposite to the first rotational direction R1, as shown in FIG. 1, the second part 18B rotates together with the second portion 12-2 and pushes axially the first part 18A via the cam follower 18B1 and the helical cam 18A1 in the second axial direction X2. The return spring 22 then pushes simultaneously the eraser 16 in abutment, via the tube holder 20, against the first part 18A. The eraser 16 is thus moved from the protruding or intermediate position (see FIGS. 5 and 6) toward the retracted position (see FIG. 4).

(19) In the present example, the writing instrument 10 may comprise a writing body 24, for example a cartridge, which may comprise the writing tip 14. The writing body 24 may also comprise an ink reservoir 25 configured to store erasable ink, for example thermochromic ink. The writing tip 14 may be fed with erasable ink by the reservoir 25. The eraser 16 may be a friction body.

(20) The writing body 24 may extend at least in part into the tube holder 20 in any position of the eraser 16. The writing body 24 may be supported, in the tube holder 20 by a support 26.

(21) The support 26 may extend inside the first part 18A and may be axially coupled with the second part 18B. The writing body 24 may be removable mounted to the support 26. For example, a rear end 24B of the writing body may be press fitted to a front portion 26A of the support 26. The support 26 may comprise a rear portion 26B, for example a rod, press fitted to the second part 18B. In an example not shown the support 26 and the second part 18B may be unitarily formed. The support 26 may stop the writing body 24 in the second axial direction X2.

(22) The writing body 24 may have a front shoulder 24A which may abut against a complementary shoulder 16D of the eraser 16. Therefore, if the writing body 24 were to be detached from the support 26, writing body 24 may remain into the body 12. For example, a maximum axial gap G (see FIG. 6) between the front shoulder 24A and the complementary shoulder 16D may be less than a maximum axial stroke D (see FIG. 3) for removing the writing body 24 from the support 26 (or a maximum axial length of the front portion 26A engaged with the writing body 24). In such a case, there is no enough axial space between the two shoulders 24A and 16D for allowing the writing body 24 to be completely detached from the support 26. Therefore, the writing body 24 may remain attached to the support 26 in any configuration of the writing instrument 10.

(23) As shown in FIGS. 4 to 6, the writing tip 14 is fixed with regard to the body 12 while the eraser 16 is movable between a retracted position (see FIG. 4) and a protruding position (see FIG. 6). When the eraser 16 is in the retracted position (see FIG. 4) or in the intermediate position (see FIG. 5) the eraser 16 may not be used and the writing tip 14 may be used for writing. When the eraser 16 is in the protruding position (see FIG. 6), the writing tip 14 is protected by the eraser 16 and may not be used and the eraser 16 may be used for erasing an erasable ink applied with the writing tip 14.

(24) The body 12 may comprise a nose cone 12-11, the nose cone 12-11 comprising the first end 12A. The nose cone 12-11 may be part of the first portion 12-1. The nose cone 12-11 may be removable from the rest of the body 12. For example, the nose cone 12-11 may be screwed with the first portion 12-1. The nose cone 12-11 may be provided with the shoulder 12C against which the return spring 22 abuts. Thus, when removing the nose cone 12-11, the return spring 22 and the eraser 16 together with the tube holder 20 may be removed and the writing body 24 may be removed for refill.

(25) Although the present disclosure is described with reference to specific examples, it is clear that modifications and changes may be made to these examples without going beyond the general scope of the disclosure. In particular, individual characteristics of the various embodiments shown and/or mentioned may be combined in additional embodiments. Consequently, the description and the drawings should be considered in a sense that is illustrative rather than restrictive.

(26) Additionally, all of the disclosed features of an apparatus may be transposed, alone or in combination, to a method and vice versa.