HK1207341B

HK1207341B - Writing instrument

Info

Publication number: HK1207341B
Application number: HK15108125.4A
Authority: HK
Inventors: Michel Willemin; Nakis Karapatis; Jean-Claude Martin
Original assignee: The Swatch Group Research And Development Ltd.
Priority date: 2012-09-18
Filing date: 2013-09-12
Publication date: 2018-09-21

Description

Writing implement

Technical Field

The invention relates to a writing instrument comprising a body extending longitudinally along a central axis and a clip extending substantially parallel to the central axis, the clip being secured to at least a portion of the body and extending to a free end.

Background

Writing instruments formed of a body extending longitudinally along a central axis C between a front end and a rear end are known in the art. The front end includes an opening through which a writing tip (not visible when retracted) may extend. At the rear end, the writing instrument has a button that actuates a tip extension/retraction mechanism. The body may be made of two parts: a cone-shaped protrusion (nose) and a tube portion to which the cone-shaped protrusion is fixed.

The writing instrument is also provided with a clip for enabling a user to clip the writing instrument to, for example, a shirt pocket. The clip comprises an arm provided at a first end with a free projection that should be in contact with the body of the writing instrument and at a second end with attachment means for fixing the clip to the body of the writing instrument. These attachment means may be a snap-fit system, i.e. the snap-fit system is inserted into a hole in the body to secure the clip. The attachment means may also take the form of a split ring encircling the body of the writing instrument.

A first drawback of such writing instruments is that they are aesthetically unpleasing and fragile. In fact, the clip is an additional component, which results in the risk of the clip being torn off during operation.

Further, the configuration has a disadvantage in that it requires a processing method in which the main body and the clip are each manufactured separately. Thus providing an additional assembly step to install a clip for each writing instrument.

Further, the material forming the clip is any metal. Each material is characterized by its young's modulus E or elastic modulus (usually expressed in GPa) which characterizes its resistance to deformation. Furthermore, each material also has its elastic limit σ_eCharacterized (usually expressed in GPa) by a specific stress beyond which the material plastically deforms. Thus, for a given thickness, the ratio σ of elastic limit to Young's modulus can be established for each material_eMaterials were compared and the ratio characterizes the elastic deformation of each material. Thus, the higher the ratio, the greater the elastic deformation of the material. However, crystalline materials such as used in the prior art provide low σ_ea/E ratio, the crystalline material being, for example, a Cu-Be alloy having a Young's modulus E equal to 130GPa and a typical elastic limit σ_eThe value 1GPa, i.e. sigma_ethe/E was about 0.007. These crystalline alloy components therefore have limited elastic deformation. In the case of a clip of a writing instrument, it is noted that a user tends to frequently operate the clip, and the clip is finally deformed or broken.

Similarly, the use of precious crystalline metals for the manufacture of such clamps cannot be envisaged, taking into account the insufficient mechanical properties of these metals. In fact, these noble metals have in particular a lower elastic limit of about 0.5GPa for Au, Pt, Pd and Ag alloys compared to the conventionally used crystalline alloys having an elastic limit of about 1 GPa. Given the elastic modulus of these noble metals (about 120GPa), theSigma of about 0.004 was obtained_eThe ratio of E to E. However, a high σ is required_ethe/E ratio produces such a clip, as explained above. Therefore, those skilled in the art are not inclined to use these precious metals to produce such clips.

Another disadvantage of the conventional writing instrument is a spring which is provided at a lower portion of the main body and provides a restoring force to extend/retract the writing tip. In fact, the spring is a separate component that sometimes disengages from the body of the writing instrument when the writing tip is replaced, which results in the loss of the basic function of the writing instrument.

Disclosure of Invention

The present invention relates to a writing instrument which overcomes the above-mentioned disadvantages of the prior art by proposing a writing instrument which is made in one piece and is made of an at least partially amorphous material.

To this end, the invention relates to a writing instrument comprising:

-a body extending longitudinally along a central axis;

-a resilient element secured to at least a portion of the body;

characterized in that said elastic element and said at least one portion of said body are in a single piece and are made of an at least partially amorphous metal alloy.

Advantageous embodiments of the writing instrument form the subject matter of the dependent claims.

In a first advantageous embodiment, the metal alloy comprises at least one noble metal element included in the list comprising gold, platinum, palladium, rhenium, ruthenium, rhodium, silver, iridium and osmium.

In a second advantageous embodiment, said clip and said at least one portion of said body are made of a material that is completely amorphous.

In a third advantageous embodiment, the material is free of cobalt, beryllium or nickel.

In another advantageous embodiment, the resilient element is a clip extending from a first end fixed to the at least one part of the body substantially parallel to the central axis to a free end.

In another advantageous embodiment, the resilient element is a spring comprising at least one element extending substantially radially towards the central axis within the at least one portion of the body.

In another advantageous embodiment, the body comprises an opening at the front end through which a writing tip extends.

In another advantageous embodiment, the body comprises at a front end a conical projection fixed to the body and having an opening through which a writing tip extends.

In another advantageous embodiment, the body further comprises a complementary member directly embedded in the body in a casting or thermoforming operation.

The invention also relates to a method for manufacturing a writing instrument according to any one of the preceding claims, characterized in that the body is obtained by:

a) taking a material for forming the main body;

b) forming the body by casting the material in a casting mold;

c) cooling the assembly to form an amorphous state in the body; and

d) and removing the main body.

Another method of manufacturing a writing instrument is characterized in that the body is obtained by:

a) forming a preform from the at least partially amorphous material;

b) heating the mold between the glass transition temperature Tg and the crystallization temperature Tx of the material;

c) disposing the preform between the molds; and

d) applying pressure on the preform with the mold for a predetermined time to replicate the shape of the mold on the respective surfaces of the preform;

e) cooling the body to maintain at least a partially amorphous state.

Advantageously, the mould or casting mould comprises a surface state, so as to directly reproduce the surface state during a casting or thermoforming operation.

Surprisingly, the noble material in amorphous form has a high σ_ethe/E ratio, making it possible to manufacture components such as clips or springs according to the invention.

A first advantage of the invention is that it has more favourable elastic properties. In fact, for amorphous materials, the elastic limit σ is raised by_eTo increase sigma_eThe ratio of E to E. Thus, a specific stress is increased above which the material does not return to its original shape. Sigma_eThe increase in the/E ratio thus allows greater deformation. This allows the size of the clip to be optimized depending on whether it is desired to increase the measurement range of the clip or to decrease the size of the clip for the same measurement range. Similarly for a spring, the restoring force can be adjusted by changing the dimensions of the spring.

Another advantage of these amorphous materials is that they provide new forming possibilities for developing complex shaped parts with higher precision. In fact, amorphous metals have the unique property of softening while remaining amorphous within a given temperature range [ Tg-Tx ] (where Tx is the crystallization temperature and Tg is the glass transition temperature) for each alloy. These metals can be formed at relatively low stress and low temperature. This means that fine geometries can be reproduced very accurately, since the viscosity of the alloy is greatly reduced and the alloy thus acquires all the details of the mold.

The invention also relates to a protective element for a writing tip of a writing instrument according to the invention, comprising a cap extending longitudinally along a central axis and arranged to be fitted to the body of the instrument, and a clip extending from a first end fixed to the cap substantially parallel to the central axis to a free end, characterized in that the clip and the cap are in one piece and are made of an at least partially amorphous metal alloy.

In a second advantageous embodiment, the clip and the cap are made of a completely amorphous material.

In another advantageous embodiment, the cap further comprises a complementary member directly embedded in the body in a casting or thermoforming operation.

The invention also relates to a method for manufacturing a protective element for a writing tip of a writing instrument, characterized in that said cap is obtained by the following steps:

a) taking a material for forming the cap;

b) forming the cap by casting the material in a mold;

c) cooling the assembly to form an amorphous state of the cap; and

d) and removing the cap.

The method for manufacturing a protective element for a writing tip of a writing instrument is further characterized in that said cap is obtained by the following steps:

a) forming a preform from the at least partially amorphous material;

c) disposing the preform between the molds; and

e) cooling the cap to maintain at least a partially amorphous state.

Drawings

The objects, advantages and features of the writing instrument according to the invention will emerge more clearly in the following detailed description of at least one embodiment of the invention, given purely by way of non-limiting example by means of the accompanying drawings, in which:

figure 1 shows a schematic longitudinal cross-sectional view of a writing instrument according to a first embodiment of the invention;

fig. 2 shows a schematic side view of a variant of the writing instrument according to the invention; and is

Figure 2a shows a schematic radial cross-section of a writing instrument according to the invention; and is

Fig. 3 shows a schematic side view of a writing instrument according to a second embodiment of the invention.

Detailed Description

Fig. 1 and 2 show a cross-sectional view of a writing instrument 1 according to a first embodiment. The writing instrument 1 comprises a body 2, said body 2 extending longitudinally along a central axis C between a front end 3 and a rear end 4. The front end includes an opening 5 through which a writing tip 6 (not visible when retracted) may extend. The writing tip 6 may be a pencil tip, a pen tip or a ball-point tip or a felt tip arranged at the end of a refill (not shown) extending longitudinally into the body 2. At the rear end 4, the writing instrument has a button 7, which button 7 can actuate a mechanism (not shown) for extending/retracting the tip.

The writing instrument is further provided with a resilient element 10, such as a clip 8, for enabling a user to clip the writing instrument to, for example, a shirt pocket. The clip 8 comprises an arm 81 provided at a first end 82 with a protruding element 83 intended to come into contact with the body of the writing instrument. The clip is secured to the body 2 of the writing instrument by the second end 84.

In a variant, the body 2 can be made in two parts: a conical projection 9 and a tube portion to which the conical projection is fixed. The body 2 can also be made of three parts, namely a first part on which the clip is fixed, a second part for holding the tool and a third part fixed to the second part, the third part being a conical projection. These three parts thus form the body 2.

Advantageously according to the invention, at least the first portion of the body 2 and the clip 8 are integral and made of a material that is completely amorphous or partially amorphous. In particular, metallic glasses, i.e. amorphous metal alloys, are used. The above-described configuration, in which at least the first portion of the body 2 and the clip 8 are integral, provides a sturdier appearance of higher quality.

In fact, the advantages of these amorphous metal alloys in terms of deformation stem from the fact that: the atoms that form the amorphous material during fabrication are not arranged in a particular structure as are crystalline materials. Therefore, even if the Young's moduli E of the crystalline metal and the amorphous metal are equal, the elastic limit σ is_eDifferent. In fact, amorphous materials differ in that they have a larger elastic limit σ than crystalline materials_eaWherein the ratio between the elastic limit of the amorphous material and the elastic limit of the crystalline material is substantially equal to 2. This allows the amorphous material to reach the elastic limit σ_ePreviously experienced greater stresses and thus experienced four to eight times greater stresses than comparable crystalline materials.

First, this configuration makes it possible to improve the reliability of the clip 8 on the writing instrument. In practice, the elastic limit σ_eaLarger, this makes it farther from the shaping field and thus reduces the risk of the clip 8 plastically deforming when the user operates the writing instrument.

Furthermore, it is advantageous to note that the use of clips 8 made of amorphous material allows the dimensions of the clips to be optimized for the same stress in order to withstand this same stress. In fact, the dimensions of the clip 8, such as its thickness, vary its deformation. Advantageously, if the elastic limit is increased, the stress that can be applied to the clip 8 without any plastic deformation increases. So that it is possible to reduce its thickness while maintaining resistance to the same stress. The clip 8 thus becomes thinner and thus less noticeable, which can be an advantage in terms of aesthetics.

In addition, amorphous materials or amorphous metal alloys have the property of being harder than their crystalline equivalents. Thus, a body 2 made of such a material will be harder and thus more durable/strong.

The following may be cited as examples of amorphous materials that may be used: zr41Ti14Cu12Ni10Be23, having Young's modulus E value of 105GPa and elastic limit sigma_e1.9GPa, and a_e0.018 and Pt57.5Cu14.7Ni5.3P22.3, having a Young's modulus E value of 98GPa and an elastic limit sigma_e1.4GPa, and a_eAnd E is 0.014. It should be understood that the alloys mentioned in the following patents are incorporated by reference into the present patent application: US5288344, US5618359 and US 7368022.

Of course, there are other features that may be advantageous, such as the allergenic aspects of the alloy. In fact, it can be noted that, whether the material is crystalline or amorphous, it is often used with alloys comprising allergens. These types of alloys include, for example, cobalt, beryllium or nickel. Thus, variations of the invention may be made from alloys that do not include these allergens. It is also permissible that allergens are present but do not cause allergic reactions.

According to another variant of the invention, it is possible that at least the first portion of the body 2 and the clip 8 are made of a precious material. In fact, in the crystalline state, noble materials such as gold and platinum are too soft to produce a flexible and strong clip 8. However, once it takes the form of metallic glass, i.e., amorphous, these precious metals may have the characteristic of being used while providing a valuable, attractive appearance. Preferably, platinum 850(Pt850) and gold 750(Au750) are the noble metals to be used for manufacturing the assembly formed by the clip 8 and at least the first portion of the body 2. Of course, other noble metals such as palladium, rhenium, ruthenium, rhodium, silver, iridium, and osmium may be used. It should be understood that the alloys mentioned in the following patents are incorporated by reference into the present patent application: WO 2006/045106 and WO 2004/059019.

It should also be noted that amorphous metal alloys are easy to shape. In fact, amorphous metals have the unique property of softening while remaining amorphous within a given temperature range (Tx-Tg) for each alloy. These metals can be shaped at relatively low stress and low temperature.

The process specifically described in U.S. patent No 2003/0047248, incorporated by reference into this patent application, involves thermoforming an amorphous preform. The preform is obtained by melting the metallic elements forming the amorphous alloy in a furnace. The melting is performed under a controlled atmosphere to obtain the smallest possible oxygen contamination of the alloy. Once these elements have melted, they are cast in semifinished form and then rapidly cooled to maintain the amorphous state. Once the preform is formed, thermoforming is performed to obtain the final part. The thermoforming is achieved by pressing for a predetermined time in a temperature range between Tg and Tx to maintain a fully or partially amorphous structure or state. This is performed such that the characteristic elastic properties of the amorphous metal are retained. The final forming steps are thus:

i. a mold having the negative/inverse shape of the assembly formed by at least the first portion of the body 2 and the clip 8 is heated to a selected temperature.

inserting the amorphous metal preform between hot dies.

Applying a closing force to the mold to replicate the geometry of the mold on the amorphous metal preform.

Wait for a selected maximum time.

v. opening the mould.

Rapidly cooling the assembly formed by the at least first portion of the body 2 and the clip 8 to a temperature below Tg, and

removing the assembly formed by the at least first portion of the body 2 and the clip 8 from the mould.

The forming method allows to reproduce very accurately fine geometries, since the viscosity of the alloy is greatly reduced and the alloy thus acquires all the details of the mold. The advantage of this method is that there is no solidification shrinkage, which allows to obtain, obtaining, more precise parts at higher temperatures than those obtained by injection molding. Furthermore, the clip and at least the first part of the body 2 may be produced in the same single step. Furthermore, the fact that at least the first portion of the body 2 and the clip 8 are in one piece reduces the risk of the clip 8 being torn off.

Of course, other types of forming, such as injection molding, may be used. The method described in detail in U.S. patent No 5711363, incorporated herein by reference, comprises molding an alloy obtained by melting a metal element in a furnace into the form of any member, such as a rod, which may be in a crystalline or amorphous state. Then, the alloy member of an arbitrary shape is remelted and injected into a mold having the shape of the final member. Once the mould is filled, it is rapidly cooled to a temperature below Tg to prevent crystallisation of the alloy and thereby obtain an assembly in amorphous or semi-amorphous metal form formed by at least the first portion of the body 2 and the clip 8.

Thus, the assembly formed by the at least first portion of the body 2 and the clip 8 can be shaped into a desired geometry.

One variant consists in forming the ornament directly during the manufacture of the assembly formed by the clip 8 and at least the first part of the body 2. To achieve this, the writing instrument 1 has decorations, for example "genevade gende ve) ", rotary circling, satin finishing or machine engraving, obtained directly in the negative impression/negative pattern impression of the casting mould or die respectively for casting and thermoforming. Thus, in addition to the advantages described above, this variant also avoids the use of heavy equipment currently used for manufacturing these series of decorations. It is clear that the method thus makes it possible to produce decorative writing instruments more quickly and with it less expensively.

Advantageously, complementary members such as pearl inlays or gems may be embedded within the writing instrument. The complementary member may be allowed to sit directly in the casting mold or on the mold during the casting or thermoforming step and be directly inlaid. The complementary member thus forms an integral part of the writing instrument rather than an additional part.

In a second embodiment, shown in fig. 3, the writing instrument 1 comprises a protective element or cap 20, which protective element or cap 20 is intended to be fixed to the body 2 and to protect the front end 3. In practice, a writing tip 6 is arranged at the front end 3 and sometimes it is necessary to protect the writing tip, especially in the case of a pencil tip or a felt tip. The cap 20 includes a member extending longitudinally along a central axis (C). The component is arranged to be fitted to the body 2 of the tool. It is envisaged that the protective element comprises a clip 80. The clip 80 extends from a first end fixed to the component substantially parallel to the central axis (C) to a free end.

Advantageously, clip 80 and said cap 20 are in a single piece and are made of an at least partially amorphous metal alloy. Naturally, all the variants described for the first embodiment can also be used for the second embodiment.

In the case of a writing instrument having a push button and a retractable pencil or ball-point pen tip, it should also be noted that the body 2 may also include a return spring 11 for the writing tip-cartridge assembly as shown in fig. 2 and 2 a. Advantageously, this spring 11 is in a single piece with the body 2 and can take the form of a perforated washer extending radially towards the centre of the body 2 to ensure the spring effect, as shown in fig. 2A, which shows a view of the spring 11 along the section axis a. Alternatively, the gasket may be replaced by a plurality of tabs extending radially towards the centre of the body 2. There may be a slight incline to ensure better operation. The use of an amorphous metal alloy makes it possible to obtain a spring that withstands greater stresses and ensures greater reliability. The return spring 11 can also be formed directly with the body 2 in a thermoforming or casting operation.

It will be clear that various modifications and/or improvements obvious to a person skilled in the art can be made to the embodiments of the invention described above without departing from the scope of the invention as defined in the appended claims.

Claims

1. Writing instrument (1) comprising:

-a body (2) extending longitudinally along a central axis (C);

-an elastic element (10) fixed to at least a portion of said body;

characterized in that said elastic element (10) and said at least one portion of said body (2) are in a single piece and are made of a metal alloy that is completely amorphous, said elastic element being a washer-shaped spring (11) comprising at least one element that extends substantially radially towards said central axis (C) within said at least one portion of said body (2).

2. The writing instrument of claim 1, wherein the metal alloy comprises at least one precious metal element included in a list comprising gold, platinum, palladium, rhenium, ruthenium, rhodium, silver, iridium, and osmium.

3. The writing instrument of claim 1, wherein the fully amorphous metal alloy is cobalt-free, beryllium-free, or nickel-free.

4. A writing instrument according to claim 1, characterized in that it comprises a clip (8) extending from a first end fixed to said at least one portion of the body substantially parallel to the central axis (C) to a free end.

5. A writing instrument according to claim 2, characterized in that it comprises a clip (8) extending from a first end fixed to said at least one portion of the body substantially parallel to the central axis (C) to a free end.

6. The writing instrument of claim 1, wherein the body includes an opening at the front end through which a writing tip can extend.

7. The writing instrument of claim 1, wherein the body includes a tapered projection at a front end that is secured to the body and includes an opening through which a writing tip can extend.

8. The writing instrument of claim 1, wherein the body further comprises a complementary member directly embedded in the body in a casting or thermoforming operation.

9. The writing instrument of claim 4, wherein the body further comprises a complementary member directly embedded in the body in a casting or thermoforming operation.

10. The writing instrument of claim 5, wherein the body further comprises a complementary member directly embedded in the body in a casting or thermoforming operation.

11. A method for manufacturing a writing instrument according to claim 1, characterized in that the body (2) is obtained by:

a) -taking the material forming the body (2);

b) forming the body by casting the material in a casting mold;

c) cooling the assembly to form the body into an amorphous state; and

d) and removing the main body.

12. A method for manufacturing a writing instrument according to claim 1, characterized in that the body (2) is obtained by:

a) forming a preform from the fully amorphous metal alloy;

b) heating the mold between the glass transition temperature Tg and the crystallization temperature Tx of the fully amorphous metal alloy;

c) disposing the preform between the molds; and

e) cooling the body (2) to maintain an at least partially amorphous state.

13. The method of making a writing instrument according to claim 11, wherein the mold includes a surface condition to directly replicate the surface condition during a casting or thermoforming operation.

14. A method of manufacturing a writing instrument according to claim 12, wherein the mould comprises a surface state so as to directly replicate the surface state during a casting or thermoforming operation.