HK1223449B - Vibration plate for a music box - Google Patents

Description

Vibrating plates for music boxes

Technical Field

The present invention relates to the field of music sheets and small-sized music boxes.

Background Art

Typically, a music box's striking mechanism consists of a vibrating plate with several strips and a triggering system that activates the strips; this triggering system can take the form of a rotating column or a rotating disk. In order to incorporate this striking mechanism into a watch, the components must be minimized while maintaining mechanical strength and good sound quality.

Currently, the material selection for the vibration plate is mainly based on manufacturability and resistance to wear and fatigue. In fact, the strips of the vibration plate are subjected to repeated elastic forces and must therefore have considerable resistance to have an acceptable lifespan.

When manufacturing vibrating plate strips, the strip's trigger energy criteria must also be considered. It's known that the shortest strips require higher trigger energy than longer strips. Shorter strips are therefore subject to greater spring forces and must be more resistant to wear and fatigue.

The oscillating plates of current striking watches suffer from a significant drawback, as they are made of a single material. This means that manufacturers must compromise on the material used to make the strips in order to achieve acceptable vibration performance for both long and short strips. This compromise does not result in optimal reproduction of high and low notes.

Summary of the Invention

An object of the present invention is to overcome all or part of the above-mentioned drawbacks by providing a vibrating plate that simultaneously meets the constraints of mechanical strength and vibration performance, regardless of the length of the strips.

Another object of the present invention is to provide a diaphragm that matches the sound levels of high and low pitches.

Another object of the invention, at least in one particular embodiment, is to propose a vibrating plate capable of limiting wear and deformation of the strips.

Another object of the present invention is to provide a compact vibration plate.

Another object of the present invention is to provide a vibration plate with a simple design and low manufacturing cost.

To this end, the present invention relates to a vibration plate comprising at least two parts connected to each other, namely a first part and at least a second part, the first part forming a first set of strips being made of a first material to produce sound in a first frequency range, and the second part forming a second set of strips being made of a second material to produce sound in a second frequency range.

Due to the above-mentioned features, this bi-material diaphragm allows for selection of an appropriate material based on the mechanical strength of the strip for reproducing sounds in a first frequency range, typically high-pitched sounds, and, on the other hand, allows for selection of an appropriate material based on the required activation energy of the strip for reproducing sounds in a second frequency range, typically low-pitched sounds. This results in a diaphragm with optimized performance for reproducing sounds within the desired diaphragm frequency range.

According to other advantageous variants of the invention:

- the first material has a Young's modulus between 150 GPa and 250 GPa, a density between 4000 kg/m ³ and 10000 kg/m ³ , a hardness greater than 300 HV and a tensile strength above 800 MPa, which makes it possible to have a more resistant material;

The second material has a Young's modulus between 70 GPa and 120 GPa, a density between 14,000 kg/m ³ and 20,000 kg/m ³ , a hardness less than 300 HV and a tensile strength less than 600 MPa, which makes it possible to use materials with higher triggering energies;

– the speed of sound in the second material is at least 40% less than the speed of sound in the first material, so as to limit the transmission of vibrations between the two parts;

The first and second parts are connected to each other by soldering, brazing or press-fitting operations to obtain a single-piece vibration plate, thereby optimizing the vibration transmission between the vibration plate and the radiation member;

- the vibrating plate comprises at least three parts, referred to as a first part, a second part and a third part;

– the first part is made of a first material, the second part is made of a second material, and the third part is made of a third material, and the speeds of sound in the three materials differ from each other by at least 30% to limit the transmission of vibrations between the two parts;

- the first material is steel or metallic glass, the second material is gold or cast iron, and the third material is platinum, brass, aluminum, metallized sapphire, Phynox, or cupronickel;

– The triggering energy of each strip is greater than or equal to 20 microwatts to obtain effective radiation.

The invention also relates to a music box comprising a music module provided with at least one vibration plate according to the invention and a triggering assembly for triggering the strips to produce music.

The invention also relates to a music watch comprising a music module provided with at least one vibration plate according to the invention and a triggering assembly for triggering the strips to produce music.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention will appear more clearly on reading the following description of a particular embodiment of the invention, given simply by way of illustrative and non-limiting examples and the accompanying drawings, in which:

- FIG. 1 is a top view of a vibration plate according to the invention according to a first embodiment.

- Figure 2 is a perspective view of a vibration plate according to the invention according to a second embodiment.

- Figure 3 is a perspective view of a vibration plate according to the invention according to a third embodiment.

- Figures 4a and 4b are perspective views of a vibrating plate according to the invention according to further embodiments.

DETAILED DESCRIPTION

A vibration plate for a small-sized music box will be described below with reference to Figures 1, 2, 3, 4a and 4b.

The present invention relates to a vibration plate 1 comprising at least two parts connected to one another and made of at least two materials, namely a first part and at least a second part, the first part forming a first set of strips 11, 12, 13, 14 and made of a first material M1 to produce sounds in a first frequency range, and the second part forming a second set of strips 21, 22, 23, 24 and made of a second material M2 to produce sounds in a second frequency range.

The first frequency range may, for example, extend from 1600 Hz to 20 kHz, which enables the reproduction of high-pitched sounds. The second frequency range may extend from 20 Hz to 400 Hz, which enables the reproduction of low-pitched sounds. A frequency range extending from 400 Hz to 1600 Hz may also be considered to reproduce mid-pitched sounds.

According to the invention, the first material M1 has a Young's modulus between 150 GPa and 250 GPa, a density between 4000 kg/m ³ and 10000 kg/m ³ , a hardness greater than 300 HV and a tensile strength above 800 MPa.

An example of a material that meets these criteria is steel. This material enables the strips that reproduce high-pitched sounds to be mechanically strong. Obviously, any other material that meets these criteria can be used to make the first set of strips 11, 12, 13, 14.

The second material M2 has a Young's modulus between 70 GPa and 120 GPa, a density between 14,000 kg/m ³ and 20,000 kg/m ³ , a hardness of less than 300 HV and a tensile strength of less than 600 MPa.

An example of a material that meets these criteria is gold. This material allows the strips that generate low-pitched sounds to store an amount of energy greater than or equal to 20 microwatts when triggered. Obviously, any other material that meets these criteria can be used to make the second set of strips 21, 22, 23, 24.

According to a particularly advantageous aspect, the use of two different materials to reproduce the high and low pitched notes enables the materials to be selected so that the triggering energies of the strips producing the high and low pitched notes are relatively close.

According to the present invention, the speed of sound in the second material M2 is at least 40% smaller than the speed of sound in the first material M1 to limit the transmission of vibrations between the first portion 10 and the second portion 20 .

According to the present invention, the first part 10 and the second part 20 are connected to each other by soldering, brazing or press-fitting operations or any other method known to those skilled in the art of producing one-piece components to obtain a one-piece vibration plate.

Connecting the two parts 10, 20 makes it possible in particular to obtain a correct positioning relative to a triggering element such as a disc or a stud. Connecting the two parts also makes it possible to optimize the transmission of vibrations between the vibrating plate and the radiating member of the music box or music watch.

According to a particular embodiment of the present invention, the vibration plate may include a first portion 10, a second portion 20, and a third portion capable of forming a third set of strips 31, 32, each portion being made of a different material. Obviously, a person skilled in the art may vary the number of portions of the vibration plate 1 to obtain the desired result without departing from the scope of the present invention.

According to a first example, given purely by way of non-limiting illustration, the first portion 10 and the second portion 20 are made of material M1 and are connected to each other by a third portion 30 made of material M2. According to this embodiment, the third portion 30 is sandwiched between the first portion 10 and the second portion 20.

According to another example, the first portion 10 and the second portion 20 are made of material M2 and are connected to each other by a third portion 30 made of material M1. The third portion 30 is also sandwiched between the first portion 10 and the second portion 20.

According to yet another embodiment shown in Figures 4a and 4b, the first portion 10 is made of a first material M1, the second portion 20 is made of a second material M2, and the third portion 30 is made of a third material M3.

According to a particularly advantageous aspect of the invention, the speeds of sound in the three materials M1, M2 and M3 differ from each other by at least 30%, so as to limit the transmission of vibrations between the two parts. This embodiment makes it possible to manufacture a vibrating plate having three parts, each part being able to reproduce sound within a specific frequency range.

Advantageously, the third material M3 used to make the third portion 30 is chosen so as to limit or even prevent the transmission of vibrations between adjacent strips of the first portion 10 and the second portion 20 .

According to an embodiment of the invention, which can be seen in FIG4 a , the third part 30 forming the connection between the first part 10 and the second part 20 can have strips 31, 32 for reproducing additional sounds. According to another embodiment, which can be seen in FIG4 b , the third part 30 can have no strips and serve only as a connecting element between the first part 10 and the second part 20.

According to the present invention, the first material M1 can be one of the following materials: steel, titanium, metallic glass, bronze, or magnesium. The second material M2 can be one of the following materials: gold, cast iron, or palladium. The third material M3 can be one of the following materials: platinum, brass, aluminum, metallized sapphire, Phynox (a cobalt-chromium-nickel alloy), or Arcap (a nickel-silver alloy).

For example, the first part 10 can be made of gold, the second part 20 can be made of steel, and the third part 30 can be made of brass. Those skilled in the art can of course make any combination they wish to obtain the desired result without departing from the scope of the present invention.

Each strip of each section 10, 20, 30 may be linear in shape, having a rectangular, circular, or other cross-section, which may be uniform along the entire length of the strip. The cross-section may also vary gradually or discontinuously along the length of each strip. The length and thickness of each strip may also vary to produce different musical notes. Each strip of each section 10, 20, 30 may have a different width.

Each strip of the vibration plate 1 is generally sized so that each strip produces a different note when it is triggered by a specific trigger element of the music module. However, it is also possible to have a pair of strips that are capable of producing the same specific note.

As can be seen from Figures 1 to 3, the number of strips in each part 10, 20, 30 can vary. Each part 10, 20, 30 of the vibration plate 1 can include an even or odd number of strips according to the requirements of a person skilled in the art to form the vibration plate 1 and reproduce the desired notes.

The invention also relates to a music box comprising a music module provided with at least one vibration plate 1 according to the invention and a triggering assembly, for example a disc or a post provided with lugs, for triggering the strips to produce music.

The invention also relates to a musical watch equipped with a musical module provided with at least one vibrating plate 1 according to the invention and a triggering assembly, for example a disc or a column provided with lugs, for triggering the strips to produce music.

Thanks to the different aspects of the invention, a vibration plate of simple design is obtained, making it possible to match the sound levels of high and low notes, and having good mechanical strength and good vibration efficiency.

Of course, the present invention is not limited to the shown examples, but may have various variations and modifications that are obvious to those skilled in the art.

Parts List

1 vibration plate

10 The first part of the vibration plate

11, 12, 13 Strips of the first part

20 The second part of the vibration plate

21, 22, 23 Strips of the second part

30 The third part of the vibration plate

31, 32 Strips of the third part

M1 First Material

M2 Second Material

M3 Third Material

Claims (17)

1. A vibrating plate (1) for a striking mechanism of a music watch or music box, characterized in that the vibrating plate (1) comprises at least two parts made of at least two materials connected to each other, namely, a first part (10) and at least a second part (20), the first part (10) forming a first set of strips (11, 12, 13, 14) being made of a first material (M1) to produce sound in a first frequency range, and the second part (20) forming a second set of strips (21, 22, 23, 24) being made of a second material (M2) to produce sound in a second frequency range. 2. The vibrating plate (1) according to claim 1, characterized in that the first material (M1) has a Young's modulus between 150 GPa and 250 GPa. 3. The vibrating plate (1) according to claim 1, characterized in that the first material (M1) has a density between 4000 kg/ ^m³ and 10000 kg/ ^m³ . 4. The vibrating plate (1) according to claim 1, characterized in that the first material (M1) has a hardness greater than 300 HV. 5. The vibrating plate (1) according to claim 1, characterized in that the first material (M1) has a tensile strength of 800 MPa or more. 6. The vibrating plate (1) according to claim 1, characterized in that the second material (M2) has a Young's modulus between 70 GPa and 120 GPa. 7. The vibrating plate (1) according to claim 1, characterized in that the second material (M2) has a density between 14000 kg/ ^m³ and 20000 kg/ ^m³ . 8. The vibrating plate (1) according to claim 1, characterized in that the second material (M2) has a hardness of less than 300 HV. 9. The vibrating plate (1) according to claim 1, characterized in that the second material (M2) has a tensile strength of less than 600 MPa. 10. The vibrating plate (1) according to claim 1, characterized in that the sound velocity in the second material (M2) is at least 40% lower than the sound velocity in the first material (M1). 11. The vibrating plate (1) according to claim 1, characterized in that the first part (10) and the second part (20) are connected to each other by soldering, brazing or press-fitting to obtain an integral vibrating plate (1). 12. The vibrating plate (1) according to any one of claims 1 to 10, characterized in that the vibrating plate (1) comprises at least three parts referred to as a first part (10), a second part (20) and a third part (30). 13. The vibrating plate according to claim 12, characterized in that the first part (10) is made of a first material (M1), the second part (20) is made of a second material (M2), and the third part (30) is made of a third material (M3), wherein the sound velocities in the three materials (M1, M2, M3) differ from each other by at least 30%. 14. The vibrating plate (1) according to claim 13, characterized in that the first material (M1) is steel or metallic glass, the second material (M2) is gold or cast iron, and the third material (M3) is platinum, brass, aluminum, metallized sapphire, Phynox or cupronickel. 15. The vibrating plate (1) according to claim 1, characterized in that the triggering energy of each strip (11,12,13,14,21,22,23,24) is greater than or equal to 20 microwatts. 16. A music box including a music module, the music module being provided with at least one vibrating plate (1) according to claim 1, and a triggering component for triggering a strip to generate music. 17. A music meter including a music module, the music module being provided with at least one vibrating plate (1) according to claim 1, and a triggering component for triggering a strip to generate music.