Stones for timekeeping movements

Abstract

To provide jewels for timekeeping movements. [Solution] The present invention relates to a stone (1) that forms a guide element for a pivot (14) of an axis (12) of a timekeeping instrument moving body (13), wherein the stone (1) comprises a main portion (23) designed to be pressed into a base (19) of a timekeeping instrument support (16) such as a plate or rod on a timekeeping instrument movement, and a hole (15) for the pivot (14) of the axis (12), wherein the stone (1) comprises a protruding portion (22) that forms a projection extending from the outer circumference of the main portion (23), and the protruding portion (22) comprises the hole (15). The present invention also relates to a rotating guide device (10) comprising such a stone (1), and a timekeeping instrument movement comprising such a guide device (10).

Description

Technical Field

[0001] The present invention relates to stones for timepiece movements, for example, industrial stones or industrial ceramics.

[0002] The present invention also relates to a timepiece movement comprising such a stone.

Background Art

[0003] In the state of the art of timepieces, stones such as ruby, zirconia (ZrO2) or sapphire are used, in particular, to form receiving stones or guiding elements known as bearings in timepieces. These receiving stones and guiding elements are designed to come into contact with a pivoting body and to rotate the pivoting body with minimal friction. Thus, the receiving stones and guiding elements form, for example, all or part of a bearing for a rotating fitting shaft. The guiding element generally comprises a through-hole for inserting a pivot shaft.

[0004] In principle, industrial synthetic stones are used within timepiece movements. In particular, the Bernoulli method is generally used for the production of single-crystalline stones. There are also polycrystalline stones produced by compressing a precursor with a compression device to obtain a raw body of a future stone. In this case, the stone is sintered and machined into a finished shape with the desired dimensions. In particular, in the case of a guiding element made from polycrystalline stone, the compression device is equipped with, for example, a wire that helps to generate an evulsion of a hole.

[0005] FIG. 1 is a schematic view of a stone 11 forming a guiding element for a pivoting body on a rotating moving body according to the prior art. The stone 11 is pressed into a support 4, in this case, into a base 2 of a bar within a timepiece movement. In some configurations, the stone 11 is arranged at an edge 8 of the support 4 when the rotating moving body requires such a position.

[0006] In this example, the stone 11 is circular and has a through hole 5, which is located at the center of the stone 11 while the stone 11 is concentric. The base 2 for the stone 11 has an opening 6 at the edge 8 of the support 4 and has two counterbore holes 3 that balance the forces applied to the stone 11. Thus the stone 11 is held by three support surfaces 7, 9, two of which are positioned between the edge 8 and the different counterbore holes 3, and the third support surface 9 is positioned between the two counterbore holes 3.

[0007] However, the surface into which the stone 11 is pressed is limited, in particular, because the width of the opening 6 within the edge 8 must be compensated for by the two counterbore holes 3. As a result, the pressing surface provided by the three support surfaces 7, 9 is insufficient, and therefore the stone 11 is not held securely in place, which may cause the stone 11 to be pushed off the base upon impact. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The present invention aims to improve all or part of the aforementioned drawbacks by providing a stone that can be pressed into a base with a larger pressing surface. [Means for solving the problem]

[0009] For this purpose, the present invention relates to a stone that forms a guide element for a pivot of the axis of a timekeeping instrument movement, the stone comprising a main portion designed to be pressed into a base of a timekeeping instrument support, such as a plate or rod, on the timekeeping instrument movement, and a hole for the pivot of the axis.

[0010] The stone is noteworthy in that it has a protruding portion that forms a projection extending from the outer periphery of the main part of the stone, and that the protruding portion has the aforementioned hole 15.

[0011] Therefore, this stone can be pressed into the base with a larger pressing surface while keeping the guide hole within the supporting opening.

[0012] In fact, the protruding portion with the hole is in the same location as the stone in conventional technology, but the main part of the stone is retained further inside the support and is larger. As a result, the indentation surface is larger, so the stone is held more securely and there is less risk of the stone being pushed out.

[0013] According to a particular embodiment of the present invention, the main part is substantially circular in shape.

[0014] According to a particular embodiment of the present invention, the main portion preferably comprises a truncated surface located opposite the protruding portion.

[0015] According to a particular embodiment of the present invention, the protruding portion is concentric semicircular in shape around the hole.

[0016] According to a particular embodiment of the present invention, the stone is, for example, a polycrystalline type containing Al2O3Cr polyruby or preferably ZrO2 zirconia.

[0017] According to a particular embodiment of the present invention, the main portion has a diameter greater than the diameter of the protruding portion.

[0018] The present invention relates to a rotational guide device for the axis of a time measuring instrument, wherein the guide device comprises a time measuring instrument support such as a plate or rod, the time measuring instrument support being equipped with a base, and such a stone is pressed into the base.

[0019] According to a particular embodiment of the present invention, the base is provided with a transverse opening at the edge of the support.

[0020] According to a particular embodiment of the present invention, the stone is placed within the base such that at least a portion of its protruding portion protrudes from the base through the lateral opening.

[0021] According to a particular embodiment of the present invention, the base is circular except for the lateral opening.

[0022] According to a particular embodiment of the present invention, the dimensions of the base correspond to the dimensions of the main part of the stone so that the stone can be pressed into it.

[0023] The present invention also relates to a timepiece movement comprising such a rotary guide device.

[0024] Other features and advantages will become more apparent from the following description with reference to the drawings. The following description is provided for illustrative purposes only and is in no way exhaustive.

Brief Description of the Drawings

[0025] [Figure 1] It is a schematic view of a rotary guide device according to a known embodiment of the prior art. [Figure 2] It is a schematic perspective view from below of a part of a timepiece movement comprising a moving body and a rotary guide device according to the present invention. [Figure 3] It is a schematic cross-sectional view of the axis of a timepiece moving body fitted within a rotary guide device according to the present invention. [Figure 4] It is a schematic top view of a rotary guide device according to the present invention. [Figure 5] It is a schematic view from below of a rotary guide device according to the present invention.

Embodiments for Carrying Out the Invention

[0026] As described above, the present invention relates to a stone 1 forming a guide element for a pivot body 14 of an axis 12 of a timepiece moving body 13 shown in FIGS. 2 to 4, and a rotary guide device 10 comprising such a stone 1. The timepiece moving body 13 is, for example, a third-wheel moving body.

[0027] The stone 1 is of a polycrystalline type and, for example, preferably contains Al2O3Cr polyruby or ZrO2 zirconia as a whole. The stone 1 comprises a main portion 23, a protruding portion 22 of the axis 12, and a hole 15 for the pivot body 14. Preferably, the stone 1 has a substantially constant thickness defined within the same plane.

[0028] The main portion 23 is designed to be pressed into the timer support 16, in this case into the base 19 of the rod in the timer movement. The main portion 23 is substantially circular in shape. The main portion 23 preferably includes a truncated surface 21 located opposite the protruding portion 22. The truncated surface 21 is approximately the same width as the opening 18 in the base 19 to compensate for any lack of force applied at this point.

[0029] According to the present invention, the stone 1 is provided with a protruding portion 22 that forms a projection extending from the outer periphery of the main portion 23, and the protruding portion 22 is provided with the hole 15.

[0030] The protruding portion 22 is a concentric semicircle with respect to the hole 15. The main portion 23 has a larger diameter than the protruding portion 22.

[0031] The main portion 23 and the protruding portion 22 of stone 1 form a material continuum.

[0032] The guidance device 10 also includes a time measuring instrument support 16, in this case a rod equipped with a base 19 for the stone 1. The dimensions of the base 19 correspond to the dimensions of the main part 23 of the stone 1 so that the stone 1 can be pressed into it.

[0033] The base 19 has a horizontal opening 18 at the edge 17 of the support 16. The base 19 is circular except for the opening 18.

[0034] Stone 1 is pushed into the base 19 such that at least a portion of the protruding portion 22 extending from the base 19 is positioned through the lateral opening 18.

[0035] Such a stone 1 is formed from a precursor which is formed as a raw material that will become a mineral body containing, for example, Al2O3Cr polyruby or ZrO2 zirconia ceramics.

[0036] For example, stone 1 is produced using a method comprising a first step in which a precursor is prepared from a mixture of at least one powder material and a binder. The powder may include aluminum oxide for forming synthetic sapphire, or a mixture of aluminum oxide and chromium oxide for forming synthetic ruby, or zirconium oxide.

[0037] In a second compression step, the precursor is compressed to form a raw material for the future stone. A third step of sintering the raw material allows for the formation of a mineral body for the future stone, which will be formed from the at least one material. The method may include a fourth machining and / or finishing step.

[0038] Naturally, the present invention is not limited to the examples shown, and various modifications and alterations are possible, as will be obvious to those skilled in the art. [Explanation of Symbols]

[0039] 1 stone 12 axes 13 Time measuring device moving object 14. Pivot Body 15 holes 16 Timekeeping support 19 units 22 Protruding part 23 Main parts

Claims

1. A stone (1) that forms a guide element for a pivot (14) of the shaft (12) of a time measuring instrument moving body (13), wherein the stone (1) comprises a main portion (23) designed to be pressed into a base (19) of a time measuring instrument support (16) such as a plate or rod of a time measuring instrument movement, and a hole (15) for the pivot (14) of the shaft (12), wherein the stone (1) comprises a protruding portion (22) that forms a projection extending from the outer circumference of the main portion (23), and the protruding portion (22) comprises the hole (15).

2. The stone according to claim 1, characterized in that the main portion (23) is substantially circular in shape.

3. The stone according to claim 1, wherein the main portion (23) preferably comprises a truncated surface (21) positioned on the opposite side of the protruding portion (22) from the center of the main portion (23).

4. The stone according to claim 1, characterized in that the protruding portion (22) is concentric semicircular in shape with respect to the hole (15).

5. The aforementioned stone (1) is, for example, Al ２ O ３ Cr polyruby or preferably ZrO ２ The stone according to claim 1, characterized in that it is a polycrystalline type containing zirconia.

6. The stone according to claim 1, characterized in that the main portion (23) has a diameter larger than the diameter of the protruding portion (22).

7. A rotary guide device (10) for the axis (12) of a time measuring instrument moving body (13), wherein the guide device (10) comprises a time measuring instrument support (16) such as a plate or rod, and the time measuring instrument support (16) is equipped with a base (19), wherein the rotary guide device (10) comprises a stone (1) as described in claim 1, and the stone (1) is pressed into the base (19).

8. The guide device according to claim 7, characterized in that the base (19) has a lateral opening (18) at the edge (17) of the support (16).

9. The guide device according to claim 8, characterized in that the stone (1) is arranged in the base (19) such that at least a portion of the protruding portion (22) protrudes from the base (19) through the lateral opening (18).

10. The guide device according to claim 8, characterized in that the base (19) is circular except for the lateral opening (18).

11. The guide device according to claim 7, characterized in that the dimensions of the base (19) correspond to the dimensions of the main portion (23) of the stone (1) so that the stone (1) can be pressed into it.

12. A timekeeping instrument movement characterized by comprising the rotating guide device (10) described in claim 7.

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