Method for manufacturing dial blank attached to support plate

Abstract

The invention relates to a method for manufacturing a dial blank (4a, 4b) of a measuring instrument, said dial blank being mounted in a support plate (3a, 3b), said method comprising: a step (34) of forming in an enclosure of a mould (2) a central cavity (9a) and a peripheral cavity (9b) defined around the central cavity, said forming step (34) comprising fitting said support plate into said enclosure, said peripheral cavity (9b) being formed in the enclosure of the mould (2); wherein the enclosure is formed by reversible assembly of a first portion (7a) and a second portion (7b) of the mold; -a forming step (36) for forming the dial blank in the central cavity and for forming an attachment element (10) in the peripheral cavity, and-a demolding step (40) for demolding the support plate from the mold, the support plate comprising the formed attachment element and the dial blank, therefore, the dial plate blank is enabled to be attached in the supporting plate.

Description

Technical Field

[0001] This invention relates to a method and system for manufacturing a dial blank for a measuring instrument mounted in a support plate / strip. Background Technology

[0002] As part of the dial of a watch made from measuring instruments (such as watches), blanks are typically made before subsequent finishing processes used to produce the dial. For dials produced in batches, or to reduce production costs, these blanks are formed in a mold using material injection molding.

[0003] More specifically, material is injected into the mold housing at an injection point located at the center of the blank to be formed. The blank is then removed from the housing by separating it from components not included in the final dial. This separation is typically accomplished by blanking, stamping, or machining with cutting tools. The disadvantages of this method include the potential damage to the blank, rendering it unsuitable for the dial to be manufactured, or soiling the blank, thus increasing the difficulty of subsequent finishing operations.

[0004] In this context, it is clear that there is a need to develop alternative solutions that do not have the aforementioned drawbacks. Summary of the Invention

[0005] The present invention aims to overcome all or part of the disadvantages mentioned above by providing a method and system for manufacturing a dial blank housed in a support plate, thereby simplifying the operation when the blank is removed from the mold, as well as the operation during the finishing process that the blank must undergo.

[0006] Therefore, one aspect of the present invention relates to a method for manufacturing a dial blank for a measuring instrument, the dial blank being mounted on a support plate, the method comprising:

[0007] - A forming step for forming a central cavity and a peripheral cavity defined around the central cavity in a mold shell, the forming step comprising assembling a support plate into the shell, the shell being formed by reversible assembly of a first part and a second part of the mold;

[0008] - A molding step for molding the dial blank in a central cavity and for molding attachment elements in peripheral cavities, and

[0009] - Demolding step for demolding a support plate from the mold, the support plate comprising the dial blank and a formed attachment element, the attachment element ensuring that the dial blank is attached to the support plate.

[0010] In other embodiments:

[0011] - During the assembly of the support plate into the housing, the central through opening and through hole of the support plate are arranged to face the central recess and peripheral recess defined in the inner surface of the first part, respectively, the inner surface participating in defining the housing of the mold;

[0012] - During the assembly of the support plate into the housing, the outlets of the material injection circuits contained in the flat receiving surface of the second part are each connected to a through hole in the support plate.

[0013] - In the molding step, material is injected into the central cavity and peripheral cavity of the mold via an outlet contained in the receiving surface of the second part;

[0014] - During injection, the material first enters each peripheral cavity until it reaches the central cavity, where it accumulates to form the dial blank;

[0015] - Once the dial blank has been formed, the injected material will continue to flow through the outlet while accumulating in each peripheral cavity to form an attachment element, which has a detachable joint to connect the attachment element to the dial blank.

[0016] - The molding step includes forming an injection point at an interface located between an outlet in the receiving surface of the second part and a through hole in the support plate;

[0017] - The molding step includes adjusting the temperature of the sealing shell by performing a cooling operation after the material is injected into the sealing shell;

[0018] -The demolding step includes separating the first part and the second part from each other;

[0019] - The demolding step includes disconnecting the injection point to form a base at one end of each attachment element, the base being flush with the bottom surface of the support plate;

[0020] - The method includes a design step for a support plate, which includes forming a central through opening and a plurality of through holes located around the central through opening in the main body thickness of the support plate.

[0021] The method further includes a preparation step for forming a central recess and a peripheral recess in a first portion from at least one original portion, the original portion being configured to form these recesses in an inner surface of the first portion; and

[0022] - The measuring instrument is a watch.

[0023] The present invention also relates to a system for manufacturing a dial blank of a measuring instrument using the method described above, the dial blank being mounted in a support plate. The system includes a mold comprising a housing having a central cavity and a peripheral cavity defined around the central cavity. The housing is formed by reversible assembly of a first portion and a second portion of the mold, the first and second portions being configured to receive the support plate. The central cavity and the peripheral cavity are configured to form the dial blank and an attachment element that ensures the dial blank is attached to the support plate. Attached Figure Description

[0024] The objects, advantages, and features of the present invention will become clearer from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0025] - Figure 1 A system for manufacturing a dial blank for a measuring instrument according to an embodiment of the present invention is shown, the dial blank being attached to a support plate / strip;

[0026] - Figure 2 A support plate according to an embodiment of the present invention is shown, which does not have a dial blank attached thereto;

[0027] - Figure 3 This is a cross-sectional view of a portion of a mold of a system according to an embodiment of the present invention, in which a support plate can be assembled;

[0028] - Figure 4 and Figure 5 A support plate according to an embodiment of the present invention is shown, the support plate including a single receiving cavity in which a formed dial blank is received, the dial blank being connected to the support plate by an attachment element;

[0029] - Figure 6 and Figure 7 A support plate according to the invention is shown, the support plate comprising a single receiving cavity for receiving a variant of a dial blank, the dial blank including a through opening and connected to the support plate by an attachment element;

[0030] - Figure 8 A support plate according to an embodiment of the present invention is shown, the support plate including a plurality of receiving cavities, each receiving cavity accommodating a dial blank; and

[0031] - Figure 9 This is a flowchart according to an embodiment of the present invention, relating to a method for manufacturing a dial blank mounted on a support plate. Detailed Implementation

[0032] Figure 1A schematic diagram of a system 1 for manufacturing at least one dial blank 4a, 4b for use in measuring instruments (e.g., watches or meters) and mounted / secured in support plates 3a, 3b is shown. It is understood that the system 1 can also be used to manufacture support plates 3a, 3b including the dial blanks 4a, 4b attached therein.

[0033] In system 1, Figures 4 to 8 Each dial blank 4a, 4b shown includes a visible surface and a hidden surface. Dial blanks 4a, 4b also include peripheral sidewalls that connect these visible and hidden surfaces to each other. It should be noted that the visible surface 17a of the blank 4a, 4b corresponds to the surface 17a that the user of the measuring instrument (e.g., a watch wearer) can see when the dial obtained from the blank 4a, 4b is installed into the measuring instrument. In other words, this surface of the blank is referred to as "visible" because it is visible when the dial made from the blank 4a, 4b is installed into the measuring instrument, unlike the other surface 17b of the blank 4a, 4b opposite to this visible surface 17a.

[0034] This system 1 can be used in an automated assembly plant (or automated assembly line) for manufacturing dials, or more generally, for manufacturing all or part of a measuring instrument. In this context, system 1 is responsible for manufacturing and supplying dial blanks 4a, 4b that are mounted / attached to support plates 3a, 3b in the automated assembly plant. The support plates 3a, 3b can then be manipulated to be arranged in another system within the plant, such as dial blank finishing systems 4a, 4b, to produce the dials that will be mounted in the measuring instruments.

[0035] refer to Figures 1 to 3 This system 1 includes, but is not limited to:

[0036] - A mold 2 formed by reversibly assembling a first part 7a and a second part 7b, the mold being able to receive support plates 3a, 3b (also called strips or support bars), the support plates being able to receive at least one dial blank 4a, 4b;

[0037] - Device 11 for injecting injectable material into the mold 2;

[0038] - Device 15 for generating a vacuum in mold 2, and / or device 16 for regulating the internal temperature of mold 2;

[0039] - Device 25 for demolding and installing support plates 3a and 3b.

[0040] In system 1, mold 2 includes a shell formed by assembling a first part 7a and a second part 7b, wherein support plates 3a and 3b can be arranged.

[0041] Support plates 3a and 3b are integrally manufactured components, and may include a single accommodating cavity 24 capable of accommodating dial blanks 4a and 4b, such as... Figures 4 to 7 As shown, or preferably including multiple similar receiving cavities 24, such as Figure 8 As shown.

[0042] To better understand the invention, a system 1 for manufacturing blanks 4a, 4b contained in a support plate 3a having a single accommodating cavity 24 will be described below. The system is similar when the support plate 3b includes multiple accommodating cavities 24. Thus, the accommodating cavity 24, also referred to as a compartment, is part of the support plate 3a, 3b, which accommodates the dial blanks 4a, 4b formed by system 1.

[0043] The support plates 3a and 3b include flat top surfaces 18a and bottom surfaces 18b that are opposite to each other. In this configuration, each receiving cavity 24 includes a central through opening 6a surrounded by a peripheral portion of the support plates 3a and 3b, which includes a plurality of through holes 6b. In this configuration, it should be understood that these holes 6b are located on the periphery of the central opening 6a. These openings 6a and through holes 6b lead to the top surface 18a and bottom surface 18b of the support plates 3a and 3b. It should be noted that each receiving cavity 24 includes at least two through holes 6b, preferably four, such as... Figure 2 and Figure 8 As shown.

[0044] Reference Figure 3 In this mold 2, the second part 7b includes a receiving surface 19b for receiving the support plates 3a, 3b. The receiving surface 19b is preferably planar, but may also include at least one cavity or an opposite / complementary shape, or include at least one protrusion or raised portion. More specifically, the support plates 3a, 3b are mounted on the receiving surface 19b of the second part 7b such that the hidden surfaces 17b of the dial blanks 4a, 4b to be formed are arranged to face, or even contact, the receiving surface 19b in whole or in part. In this configuration, the visible surfaces 17a of the dial blanks 4a, 4b to be formed are positioned to face, or contact, the inner surface 19a of the first part 7a in whole or in part. In other words, the support plates 3a, 3b, and therefore the dial blanks 4a, 4b, are arranged within the shell of the mold 2 by being sandwiched between the first part 7a and the second part 7b of the mold 2.

[0045] The inner surface 19a of the first portion 7a of mold 2 includes a central portion 20a and a peripheral portion 20b. The central portion 20a of the inner surface 19a is designed as a central region 21 facing the receiving surface 19b of the second portion 7b. The area of ​​the central portion 20a and the central region 21 is similar to, but smaller than, the area of ​​the central opening 6a of the support plate 3a. The central portion 20a includes a single recess 5a, also referred to as a central recess 5a. The central recess 5a is configured as follows:

[0046] - Defines (or at least helps to define) various features of the dial blanks 4a, 4b, such as their overall shape, the shape of their axial and / or cross-sections, their thickness, and / or

[0047] - In the thickness of the dial blanks 4a and 4b, the visible surface 17a of the dial blanks to be formed is constructed (or at least facilitates the construction) by forming at least one pattern, at least one raised portion, at least one hollow portion, at least one cut, and / or by forming at least one blind hole or even a through hole. Figure 6 and Figure 7 (See in the middle).

[0048] In other words, the central recess 5a may have at least one hollow shape and / or at least one raised or protruding portion. The central portion 20a of the inner surface 19a of the first part 7a and the central region 21 of the receiving surface 19b of the second part 7b together form the central cavity 9a of the mold 2, in which the dial blanks 4a and 4b are formed / made.

[0049] Regarding the peripheral portion 20b of the inner surface 19a, it is preferably flat and includes a plurality of recesses 5b, also referred to as peripheral recesses 5b. These recesses 5b are configured to facilitate the forming / manufacturing of element 10 for attaching dial blanks 4a, 4b to support plate 3a. Preferably, each recess 5b is configured to form an attachment element 10, which consists of two parts: a portion 12a for anchoring to support plate 3a, and a portion 12b for connecting the anchoring portion 12a to the sidewalls of dial blanks 4a, 4b. The engagement between the peripheral portion 20b of the inner surface 19a of the first portion 7a, the receiving surface 19b of the second portion 7b, and support plate 3a facilitates the formation of a plurality of peripheral cavities 9b in mold 2, in which the attachment element 10 is formed / made. It should be noted that each peripheral cavity 9b includes a through hole 6b formed in the peripheral portion of support plates 3a, 3b. The number of peripheral cavities 9b in the mold 2 is the same as the number of through holes 6b on the peripheral portions of the support plates 3a and 3b. It should be noted that when the support plates 3a and 3b are arranged in the mold 2, each of these through holes 6b is positioned as an outlet 23 facing the injection circuit 8, which is wholly or partially defined within the body of the second portion 7b. In other words, the receiving surface 19b of the second portion 7b has the same number of outlets 23 as the number of through holes 6b on the support plates 3a and 3b. These outlets 23 are defined in the peripheral portion of the receiving surface 19b. Each outlet 23 is connected to an injection device 11 for injectable material via the injection circuit 8 defined in the second portion 7b of the mold 2.

[0050] In this configuration, outlet 23 is the sole path in system 1 for injecting injectable material into mold housing 2 for both forming / manufacturing dial blanks 4a, 4b and attachment element 10. When the injectable material is injected into the housing, it first passes through each peripheral cavity 9b, specifically through each through-hole 6b, until it reaches the central cavity 9a. The material then accumulates in the central cavity 9a until it is filled to form the dial blanks 4a, 4b. Once the blanks 4a, 4b are formed, material continues to be injected and accumulates in each peripheral cavity 9b to form the attachment element 10. It should be noted that temperature regulation inside the mold 2 used for injecting material into the mold housing is ensured by circulation of either cooling or heating fluid in a secondary loop included in the second part 7b. This temperature control is performed by a device 16 for regulating the temperature of the mold 2.

[0051] As described above, each peripheral cavity 9b forms an attachment element 10 consisting of two parts: an anchoring portion 12a and a connecting portion 12b. The connecting portion 12b, composed of solidified injection-molded material, is used to connect the sidewalls of the dial blanks 4a and 4b to the anchoring portion 12a. The anchoring portion 12a consists of a first part and a second part. The first part is overmolded onto the top surface 18a of the peripheral portion of the support plates 3a and 3b, and the second part is located within the through-hole 6b. The first and second parts work together to help ensure that the attachment element 10 is securely attached to the support plates 3a and 3b, thereby ensuring that the dial blanks 4a and 4b are securely attached to the same support plates 3a and 3b. It should be noted that in this configuration, one end of the formed attachment element 10 includes a detachable joint 14 that connects the attachment element 10 to the sidewalls of the dial blanks 4a and 4b. The joint 14 is specifically designed to be detachable, especially during the operation of removing the dial blanks 4a and 4b from the support plates 3a and 3b.

[0052] Furthermore, in this configuration, the portion of the solidified injectable material located at the interface (between the outlet 23 contained in the receiving surface 19b of the second portion 7b and the corresponding through-hole 6b) is formed as an injection point 13. The cross-section of this injection point 13 is preferably smaller than the cross-section of the through-hole 6b and / or the outlet 23. Therefore, it can be understood that the cross-section of this injection point 13 is smaller than the cross-section of the second portion of the anchoring portion 12a of the attachment element 10. This injection point 13 is configured to be breakable, particularly when the support plates 3a, 3b are separated from the second portion 7b. In fact, by connecting the support plates 3a, 3b to the stalk 22 formed in the mold 2, the injection point 13 helps to hold the support plates 3a, 3b and, consequently, the dial blanks 4a, 4b on the second portion 7b.

[0053] It should be noted that the material handle 22 (such as Figures 4 to 7 (As shown) includes:

[0054] -The first part is formed by the solidification of injectable material in the central cavity 9a;

[0055] - The second part is formed by the solidification of injectable material in each peripheral cavity 9b;

[0056] - The third part is formed by the solidification of injectable material in the injection circuit 8 provided in the second part 7b.

[0057] As already mentioned, in this mold 2, the second part 7b is designed to be reversibly assembled with the bottom surface 18b of the support plates 3a, 3b. The second part 7b includes at least one injection circuit 8 for injectable material, the first end of which is connected to the injection device 11, and each second end has an outlet 23 communicating with each through-hole in the support plate 3a. In this case, it is understood that the number of second ends included in the injection circuit 8 is the same as the number of outlets 23 formed in the receiving surface 19b of the second part 7b. It should be noted that when the system 1 is equipped with a vacuum device 15 for the mold 2, the device 15 is configured to generate a vacuum in the mold shell 2 containing the central cavity 9a and peripheral cavities 9b. In this configuration, as previously mentioned, one of the functions of the second part 7b is to deliver injectable material to each cavity 9a, 9b and, if necessary, generate a vacuum around them.

[0058] In system 1, the injectable material used is, for example, an organic material and / or a composite material, or a metallic or ceramic material, or a thermoformable, thermosetting, or thermoplastic material. Examples of such materials may include the following:

[0059] -SLN type charged plastics (phosphorescent) and colored and / or fluorescent pigments;

[0060] - Ceramic-filled polymers with or without colored pigments;

[0061] - Additives used to give a metallic appearance or glossy appearance, such as aluminum powder or metal powder;

[0062] - Additives that make the polymer conductive (for technical reasons, or for use in chemical / electroplating or other post-treatments);

[0063] - An additive that imparts an aesthetic effect to mimic a certain material (mother-of-pearl, stone, etc.);

[0064] - Additives that impart specific mechanical and / or tribological properties;

[0065] -BMG, commonly known as "bulk metal glass";

[0066] -Oxidation-resistant materials;

[0067] -Sinterable metallic materials;

[0068] -ceramics;

[0069] - Silicon, and / or

[0070] -A combination of any one or more of these elements.

[0071] Reference Figure 9The system 1 employs a method for manufacturing dial blanks 4a and 4b for measuring instruments, wherein the dial blanks 4a and 4b are mounted in or attached to support plates 3a and 3b. In other words, the system 1 is configured to employ this method for manufacturing support plate 3a, wherein support plate 3a contains dial blanks 4a and 4b for measuring instruments.

[0072] The method includes a step 30 of designing support plates 3a and 3b, wherein step 30 includes forming a central opening 6a extending through the main thickness of the support plates 3a and 3b, and through holes 6b located around the opening 6a. It should be noted that in step 30, the support plates 3a and 3b are selected from plates made of metal, metal alloys, and / or polymers.

[0073] The method further includes step 31, for forming a central recess 5a and a peripheral recess 5b from at least one original portion in the first portion 7a, said original portion being designed or intended to form these recesses 5a, 5b in the inner surface 19a of the first portion 7a. In this context, step 31 is responsible for forming the same number of peripheral recesses 5b as the number of through holes 6b in the support plate 3a.

[0074] The original portion (also referred to as the "master" portion) includes a central portion 20a designed to form the central recess 5a. The shape of the central portion 20a is similar to that of the dial blanks 4a, 4b to be manufactured / formed. The central portion also includes a region whose surface is similar to the expected / desired visible surface 17a of the dial blanks 4a, 4b. The original portion also includes a peripheral portion having regions for forming the peripheral recesses 5b. These regions are all shaped similarly to the fasteners 10 used to connect the formed dial blanks 4a, 4b to the support plates 3a, 3b. It should be noted that, in one embodiment of the invention, the number of original portions required for step 31 is the same as the number of recesses 5a, 5b to be formed.

[0075] In this context, preparation step 31 includes a sub-step 32 of designing the original portion using photolithography. The photolithography technique is selected from the following techniques known in the prior art, which will not be elaborated here: ultraviolet projection lithography, UV, MUV or DUV projection lithography, immersion lithography, double patterning lithography, extreme ultraviolet lithography, and nanoimprint lithography. It should be noted that other techniques can be used as supplements or alternatives to photolithography, such as laser ablation.

[0076] The preparation step 31 then includes a sub-step 33 that reproduces the original part by copying its negative form. This sub-step 33 specifically uses a Ni pad or BMG (an abbreviation for "bulk metallic glass") type replication technique known in the art, which will not be described further herein.

[0077] The method then includes step 34 of forming a central cavity 9a and peripheral cavities 9b within the shell of the mold 2. These peripheral cavities 9b are defined around the central cavity 9a or its periphery. Step 34 includes a sub-step 35 of assembling support plates 3a, 3b into the shell, which is formed by the reversible assembly of the first portion 7a and the second portion 7b of the mold 2.

[0078] In this sub-step 35, support plates 3a and 3b are positioned on the receiving surface 19b of the second portion 7b. The support plates 3a and 3b are positioned such that each outlet 23 of the respective second end of the injection circuit 8 engages / connects with the corresponding through-hole 6b of the support plates 3a and 3b. This sub-step 35 facilitates establishing an optimal connection between each outlet 23 and each corresponding through-hole 6b of the support plate 3a; in other words, mates the through-hole 6b with the outlet 23. It should be understood that the number of outlets 23 (and therefore the number of second ends) of the circuit 8 is the same as the number of through-holes 6b of the support plates 3a and 3b. In this sub-step 35, the top surface 18a of the support plates 3a and 3b mates with the central recess 5a and peripheral recess 5b defined on the inner surface 19a of the first portion 7a to facilitate the preparation / forming of the dial blanks 4a and 4b and the element 10 for attaching the blanks 4a and 4b to the support plates 3a and 3b. It should be noted that in this configuration, the central opening 6a of the support plates 3a and 3b is positioned to face the central recess 5a, and the through hole 6b is positioned to face the peripheral recess 5b.

[0079] The method then includes step 36 for forming the dial blanks 4a and 4b in the central cavity 9a and for forming the attachment element 10 in the peripheral cavity 9b. Step 36 includes a sub-step 38 of injecting material into the mold housing 2. In this sub-step 38, material is injected into the central cavity 9a and peripheral cavities 9b of the housing. The material is injected into the housing via each outlet 23 of the loop 8 contained in the receiving surface 19b of the second portion 7b. More specifically, as the material is injected via each outlet 23 into the corresponding through-hole 6b of each peripheral cavity 9b, it first passes through each peripheral cavity 9b until it reaches the central cavity 9a, where it accumulates and fills the central cavity 9a to form / shape the dial blanks 4a and 4b.

[0080] Once the dial blanks 4a and 4b are formed, material continues to flow from each outlet 23, accumulating in each peripheral cavity 9b until it is filled to form the attachment element 10. In this context, the anchoring portion 12a of the attachment element 10 comprises a first portion and a second portion, wherein the first portion is overmolded onto the top surface 18a of the peripheral portion of the support plate 3a, and the second portion is formed in the through-hole 6b. As for the connecting portion 12b of the attachment element 10, it is formed to extend substantially perpendicular to or strictly perpendicular to the peripheral sidewalls of the formed dial blanks 4a and 4b. Each connecting portion 12b formed in this manner includes a detachable joint 14 for connecting / joining the connecting portion 12b to the peripheral sidewalls.

[0081] It should be noted that during step 36, the temperature within mold 2 is regulated. This temperature regulation facilitates the injection of material into its shell by controlling the circulation of cooling or heating fluid in the secondary loop contained in the second part 7b. This regulation is performed by the temperature regulating device 16 of mold 2. Subsequently, the injected material occupies the entire volume defined in the central cavity 9a and peripheral cavities 9b of the shell.

[0082] It should be noted that during this injection sub-step 38, an injection point 13 is formed at the interface between each outlet 23 included in the receiving surface 19b of the second part 7b and the through hole 6b of the support plates 3a, 3b. As described above, the injection point 13 connects one end of each formed attachment element 10 to the end of the stalk 22 included in the corresponding outlet 23.

[0083] Therefore, such molding step 36 may include the following sub-steps:

[0084] - Before performing sub-step 38 for injecting the injectable material into the central cavity 9a and peripheral cavities 9b, a vacuum 37 is created in these cavities 9a, 9b, and / or

[0085] - Adjust the temperature of mold 39 during the following time period to adjust the temperature of cavities 9a and 9b:

[0086] • The period of time from the start of sub-step 38, in which the injectable material is injected into the casing, until the end of sub-step 38, and / or

[0087] • A period of time during which the cooling operation on the casing begins after the injection sub-step 38 ends.

[0088] Performing these vacuum and temperature conditioning sub-steps 37 and 39 is to ensure the structural uniformity of the dial blanks 4a, 4b and the attachment elements 10, in order to eliminate any defects that may exist in or on the blanks 4a, 4b and / or these attachment elements 10. For example, such defects may be welds present on the visible surface 17a of the dial blanks 4a, 4b after the two streams of injectable material converge in the central cavity 9a.

[0089] When performing vacuum sub-step 37, fluids (e.g., gases such as air) present in the enclosure can be removed from the enclosure before performing injection sub-step 38.

[0090] Before performing injection sub-step 38, when performing sub-step 39 for adjusting the hot mold temperature of the casing (more specifically, adjusting the temperature inside the casing), the casing can be heated to a temperature higher than or significantly higher than the temperature at which the injectable material supplied by the device 11 for injecting material changes from a liquid to a solid state. For example, if the material is a thermoplastic, this transition temperature is called the glass transition temperature. Thereafter, once injection sub-step 38 for the injectable material has been performed (i.e. completed), sub-step 39 will perform a cooling operation on the casing.

[0091] The method then includes step 40 for demolding the support plates 3a, 3b, comprising the dial blanks 4a, 4b and the formed attachment elements 10, from the mold 2. This step 40 includes a sub-step 41 for separating the first portion 7a and the second portion 7b from each other. In other words, the first portion 7a and the second portion 7b are separated from each other. This demolding step 40 includes a sub-step 42 for disconnecting the injection points 13. The injection points 13 are configured such that their disconnection facilitates / enables that the base of the end of each obtained attachment element 10 is substantially flush with the bottom surface 18b of the support plates 3a, 3b. In this sub-step 42, a force is applied to the support plates 3a, 3b, which are provided with the dial blanks 4a, 4b, to cause rotational and / or translational displacement of the support plates 3a, 3b relative to the outlet 23 (and therefore relative to the second portion 7b), thereby causing each injection point 13 to break. It should be noted that once the injection point 13 breaks, the base of the free end of each attachment element 10 at this time (especially the free end of the second part of its anchoring portion 12a) is substantially flush with or strictly flush with the bottom surface 18b of the support plates 3a, 3b.

[0092] Once the support plates 3a and 3b, to which the formed dial blanks 4a and 4b are securely attached, are removed from the mold 2, the support plates 3a and 3b can be freely manipulated without detaching the blanks from their bodies. For example, the support plates 3a and 3b can be manipulated to assemble / install them into a receiving cavity in the system for finishing the blanks 4a and 4b. This receiving cavity is configured to receive the support plates 3a and 3b so that finishing operations can be performed on the dial blanks 4a and 4b. It should be noted that the second portion of the anchoring portion 12a of each attachment element facilitates the assembly of the support plates 3a and 3b into the receiving cavity, the base of which is flush with the bottom surface 18b of the support plates 3a and 3b. In other words, the support plates 3a and 3b containing the dial blanks 4a and 4b retain a flat bottom surface 18b.

[0093] For example, such a finishing system may include:

[0094] - Construct, mount, or apply at least one pattern on the visible outer surface 17a of the dial blanks 4a, 4b;

[0095] - Apply a coating to all or part of the dial blanks 4a, 4b, for example by depositing decorative and / or functional materials on the visible surface 17a.

[0096] Furthermore, once the dial blanks 4a and 4b have been finished, they can be detached from the support plates 3a and 3b for installation in measuring instruments. In practice, the end of each attachment element 10 is connected to the dial blanks 4a and 4b via a detachable joint 14 configured to break when a force is applied to the dial blanks 4a and 4b, thereby detaching / separating the dial blanks 4a and 4b from the support plates 3a and 3b.

[0097] the term

[0098] 1. Manufacturing System

[0099] 2. Mold

[0100] 3a, 3b. Support plate

[0101] 4a, 4b. Dial blanks

[0102] 5a. Central depression

[0103] 5b. Peripheral depression

[0104] 6a. Central through opening

[0105] 6b. Through hole

[0106] 7a. Part One

[0107] 7b. Part Two

[0108] 8. Injection circuit

[0109] 9a. Central cavity

[0110] 9b. Peripheral cavity

[0111] 10. Attachment components

[0112] 11. Injection device

[0113] 12a. Anchoring portion of the attachment element

[0114] 12b. Connection part of the attachment element

[0115] 13. Injection point

[0116] 14. Disconnectable joint

[0117] 15. Vacuum device

[0118] 16. Adjustment device

[0119] 17a. Visible surfaces of the dial blank

[0120] 17b. Hidden surfaces of the dial blank

[0121] 18a. Top surface of the support plate

[0122] 18b. Bottom surface of the support plate

[0123] 19a. Inner surface of the first part

[0124] 19b. Surface used to receive the second part

[0125] 20a. The central portion of the inner surface

[0126] 20b. Peripheral portion of the inner surface

[0127] 21. The central area of ​​the receiving surface

[0128] 22. Material handle

[0129] 23. Outlet of the injection circuit

[0130] 24. The receiving cavity of the support plate

[0131] 25. Demolding and assembly equipment

Claims

1. A method for manufacturing a dial blank (4a, 4b) for a measuring instrument, said dial blank (4a, 4b) being mounted in a support plate (3a, 3b), said method comprising: - Forming step (34) for forming a central cavity (9a) and a peripheral cavity (9b) defined around the central cavity (9a) within the shell of the mold (2), the forming step (34) comprising assembling (35) the support plates (3a, 3b) into the shell, wherein the shell is formed by reversible assembly of a first part (7a) and a second part (7b) of the mold (2); - Molding step (36) for molding the dial blank (4a, 4b) in the central cavity (9a) and molding the attachment element (10) in the peripheral cavity (9b), and - Demolding step (40) for demolding the support plate (3a, 3b) from the mold (2), the support plate including the formed attachment element (10) and the dial blank (4a, 4b) thereby ensuring that the dial blank (4a, 4b) is attached to the support plate (3a, 3b).

2. The method according to claim 1, wherein, During the assembly (35) of the support plates (3a, 3b) into the housing, the central through opening (6a) and through hole (6b) of the support plates (3a, 3b) are respectively arranged to face the central recess (5a) and peripheral recess (5b) defined in the inner surface (19a) of the first portion (7a), which in turn defines the housing of the mold (2).

3. The method according to any one of the preceding claims, characterized in that, During the assembly (35) of the support plates (3a, 3b) into the housing, the outlets (23) of the material injection circuits (8) contained in the flat receiving surface (19b) of the second part (7b) are each connected to a through hole (6b) of the support plates (3a, 3b).

4. The method according to any one of the preceding claims, wherein, In the molding step (36), material is injected (38) into the central cavity (9a) and peripheral cavity (9b) of the mold (2) via an outlet (23), wherein the outlet (23) is contained in the receiving surface (19b) of the second part (7b).

5. The method according to claim 4, wherein, When injected (38), the material first enters each peripheral cavity (9b) until it reaches the central cavity (9a) and accumulates in the central cavity (9a) to form the dial blank (4a, 4b).

6. The method according to claim 5, wherein, Once the dial blanks (4a, 4b) have been formed, the injected material continues to flow through the outlet (23) and accumulates in each peripheral cavity (9b) to form the attachment element (10), which has a detachable joint (14) for connecting the attachment element (10) to the dial blanks (4a, 4b).

7. The method according to any one of the preceding claims, wherein, The molding step (36) includes forming an injection point (13) at an interface, wherein the interface is located between an outlet (23) contained in the receiving surface (19b) of the second part (7b) and a through hole (6b) of the support plate (3a, 3b).

8. The method according to any one of the preceding claims, wherein, The molding step (36) includes: after the material has been injected into the shell, adjusting (39) the temperature of the shell by performing a cooling operation on the shell.

9. The method according to any one of the preceding claims, wherein, The demolding step (40) includes separating the first part (7a) from the second part (7b) (41).

10. The method according to claim 9, wherein, The demolding step (40) includes disconnecting (42) the injection point (13) to form a base at one end of each attachment element (10), the base being flush with the bottom surface (18b) of the support plate (3a, 3b).

11. The method according to any one of the preceding claims, wherein, The method includes a design step (30) for the support plate (3a, 3b) to form the central through opening (6a) and a plurality of through holes (6b) located around the central through opening (6a) in the main body thickness of the support plate (3a, 3b).

12. The method according to any one of the preceding claims, wherein, The method includes a preparation step (31) for forming a central recess (5a) and a peripheral recess (5b) in the first part (7a) from at least one original part, the original part being configured to form these recesses (5a, 5b) in the inner surface (19a) of the first part (7a).

13. The method according to any one of the preceding claims, wherein, The measuring instrument is a watch.

14. A system (1) for manufacturing a dial blank (4a, 4b) of a measuring instrument using the method according to any one of claims 1 to 12, wherein the dial blank (4a, 4b) is mounted in a support plate (3a, 3b), the system (1) comprising a mold (2) including a housing comprising a central cavity (9a) and a peripheral cavity (9b) defined around the central cavity (9a), the housing being formed by reversible assembly of a first portion (7a) and a second portion (7b) of the mold (2), the first portion (7a) and the second portion (7b) being configured to receive the support plate (3a, 3b), the central cavity (9a) and the peripheral cavity (9b) being configured for molding the dial blank (4a, 4b) and an attachment element (10) ensuring that the dial blank (4a, 4b) is attached to the support plate (3a, 3b).

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