Injection mold for timepiece component

Patent metadata

Field	Value
Publication number	US-11858178-B2
Application number	US-202117490044-A
Country	US
Kind code	B2
Filing date	Sep 30, 2021
Priority date	Oct 12, 2020
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

The injection mold has a mold core including a first part and a second part. The parts are mobile relative to one another between a first injection position in which they are moved together to form an injection cavity permitting the injection of a material to form an injected part ( 50; 50 ′), and a second demolding position in which they are moved away from one another to permit the demolding of the injected part ( 50; 50 ′). The injection mold has at least one ejector designed to contribute to the demolding, and at least one movable intermediate plate ( 10; 10′, 20 ′), separate from the two parts of the mold core. The intermediate pate is arranged between the two parts of the mold core, and has at least one cutout ( 12; 12′, 22 ′) forming at least one part of the injection cavity of the injection mold.

First claim

The invention claimed is:

1. An injection mold, comprising:
a mold core comprising a first part and a second part, wherein the first part and the second part are mobile relative to one another between a first injection position in which the two parts are moved together to form an injection cavity permitting the injection of a material to form an injected part comprising at least one component, and a second demolding position in which the two parts are moved away from one another to permit the demolding of the injected part,
at least one ejector designed to contribute to the demolding of the injected part, and
at least one intermediate plate, which is separate from the two parts of the mold core, and movable,
wherein the at least one intermediate plate is arranged between the two parts of the mold core, and has at least one first cutout forming at least one part of the injection cavity of the injection mold,
wherein, in the injection cavity, a respective surface of each of (i) the mold core, (ii) the at least one first cutout of the intermediate plate, and (iii) the at least one ejector contributes to defining a shape of the injected part.

2. The injection mold as claimed in claim 1 , wherein the two parts of the mold core are mobile relative to one another in translation in a direction of the mold, and wherein the at least one intermediate plate is present as a substantially planar plate positioned in a plane perpendicular to the direction of the mold.

3. The injection mold as claimed in claim 1 , wherein the at least one first cutout of the at least one intermediate plate is a through-opening.

4. The injection mold as claimed in claim 1 , wherein the at least one intermediate plate also comprises at least one blind cutout, at least one texturization of the surface of the plate forming at least one part of the injection cavity, or at least one blind cutout and at least one texturization of the surface of the plate forming at least one part of the injection cavity.

5. The injection mold as claimed in claim 1 , wherein the injection mold comprises at least two intermediate plates which are at least partially superposed, each of the at least two intermediate plates comprising at least one respective first cutout, and each of the at least two intermediate plates delimiting at least one part of the injection cavity, the respective first cutouts being superposed.

6. The injection mold as claimed in claim 1 , wherein the at least one ejector makes it possible to eject an injected part, by passing through the at least one first cutout of the at least one intermediate plate.

7. The injection mold as claimed in claim 1 , wherein the at least one intermediate plate comprises at least one additional cutout, which is a through-opening and is separate from the first cutout, the at least one additional cutout being designed for the passage of at least one additional ejector.

8. The injection mold as claimed in claim 1 , wherein the injection cavity which is configured to form an injected part comprising at least one component is principally delimited by:
the first part of the mold core, at least one ejector of the first part, or the first part of the mold core and at least one ejector of the first part,
the at least one first cutout of the at least one intermediate plate,
at least one end of at least one second ejector, and
the second part of the mold core.

9. The injection mold as claimed in claim 1 , wherein the first part of the mold core, the second part of the mold core, or both the first part and the second part of the mold core, against which the at least one first intermediate plate bears, is or are planar.

10. The injection mold as claimed in claim 1 , wherein the at least one intermediate plate comprises a plurality of first cutouts designed to define simultaneously the geometry of a plurality of injected components, and the injection cavity comprises a section located in a plane parallel to that of the at least one intermediate plate which is configured so that the different injected components remain connected together by an injection-molded support after ejection from the injection mold.

11. The injection mold as claimed in claim 1 , wherein the intermediate plate is in a material having a mechanical resistance designed to support the pressure of an injection mold and having a geometric stability up to a temperature of at least 100° C.

12. The injection mold as claimed in claim 1 , wherein flanks of the at least one first cutout define a peripheral lateral surface of the component, and wherein a distal surface of the ejector arranged in the injection cavity defines a surface of a portion of the component having greater thickness than a thickness of the peripheral lateral surface of the component.

13. The injection mold as claimed in claim 2 , wherein the intermediate plate further comprises at least one blind cutout, at least one texturization of the surface of the intermediate plate forming the injection cavity, or at least one blind cutout and at least one texturization of the surface of the intermediate plate forming the injection cavity.

14. The injection mold as claimed in claim 2 , wherein the intermediate plate comprises at least one additional cutout permitting passage of at least one additional ejector of an injection mold.

15. The injection mold as claimed in claim 5 , wherein each of the intermediate plates comprises at least one additional cutout, which is a through-opening, the respective additional cutouts being at least partially superposed so as to permit the passage of a respective same ejector.

16. The injection mold as claimed in claim 10 , wherein the injection mold comprises at least one mobile ejector making it possible to eject the injected part by acting in a region of the injected support.

17. The injection mold according to claim 12 , wherein the distal surface of the ejector is arranged in a through-hole of another intermediate plate located in a plane parallel to a plane of the at least one intermediate plate.

18. A method for the manufacture of an intermediate plate for an injection mold, wherein the method comprises:
manufacturing the intermediate plate by galvanic deposition, by machining a metal plate, or by stamping, and
assembling the intermediate plate, an injector and a mold core,
so as to obtain the injection mold according to claim 1 .

19. A method for the manufacture of a timepiece component or a timepiece, wherein the method comprises:
providing the injection mold as claimed in claim 1 , and
injecting a material into the injection cavity of the injection mold.

20. The method for the manufacture of a timepiece component or a timepiece as claimed in claim 19 , wherein the injected material is a ceramic-based material.

21. The method for the manufacture of a timepiece component or a timepiece as claimed in claim 19 , wherein the timepiece component is a pawl.

22. The method for the manufacture of a timepiece component or a timepiece as claimed in claim 19 , wherein the method comprises
selecting at least one intermediate plate adapted to the injection mold among a set of different intermediate plates, and
inserting the selected intermediate plate into the injection mold before injecting the material.

Assignees

• Rolex Sa

Inventors

• Fluri Grégoire
• Mincone Laurent

Classifications

• B29C33/442 Primary

  with mechanical ejector or drive means therefor · CPC title

• B29C33/301

  Modular mould systems [MMS], i.e. moulds built up by stacking mould elements, e.g. plates, blocks, rods (B29C33/0088 takes precedence) · CPC title

• B29C33/76

  Cores (B29C33/02 - B29C33/70, {B29C41/40, B29C53/74, B29C53/82} take precedence) · CPC title

• B29C45/1751

  Adjustment means allowing the use of moulds of different thicknesses · CPC title

• B29C45/40 Primary

  Removing or ejecting moulded articles · CPC title