How to manufacture an escapement anchor

Abstract

This invention provides a manufacturing method that allows for limiting the number of machines required to machine the ankle to just one, while also limiting the number of parts that need to be modified. [Solution] A method for manufacturing an ankle 1, comprising the steps of: a) forming guide holes in a strip; b) milling the strip; c) creating a bevel over at least half the thickness of the strip to form the body 2 of the ankle, including horns 50, 51 and two arms 20, 21; d) milling the outer shell of the ankle body 2 over two-thirds the thickness of the strip; e) milling rough cutouts 3, 4 on each of the arms 20, 21 over the entire thickness of the strip; f) correcting the cutouts 3, 4 and the fork 5 using a broaching tool; and g) laser blanking to separate the ankle from the strip.

Description

Technical Field

[0007] , ,

[0001] The present invention relates to the field of watchmaking technology. More specifically, it relates to a method for manufacturing watch parts, particularly the escape wheel fork for a watch.

Background Art

[0002] In the field of watchmaking technology, some applications require the use of complex parts that need a number of machining operations.

[0003] This is the case, for example, of a fork that requires a number of machining operations using multiple machines during laser blanking. Such a method requires parts to be corrected after their manufacture, which is costly and time-consuming.

[0004] The escape wheel fork can also be manufactured by stamping, but in the case of small-scale production, this method is very expensive and thus not of much interest.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, one object of the present invention is to provide a simpler manufacturing method that makes it possible to limit the number of parts to be corrected while reducing the number of machines required for machining the fork to one.

Means for Solving the Problems

[0006] For this purpose, the present invention relates to a method for manufacturing a fork for an escape system.

[0007] According to the present invention, the method comprises step a) of providing a strip of metal or metal alloy and forming guide holes in the strip to guide the strip; and step b) of machining the strip to form a horn. Step c) creating a bevel to form the body of an anchor, the first end of which includes a horn and the second end of which includes two arms, the bevel being made over a portion of the thickness of the strip so that the body of the anchor remains attached to the strip, Step d) is to mill the outer shell of the ankle body, wherein the milling is performed on a portion of the thickness of the strip in the same way as in the previous step d), Step e) involves milling a notch into each of the arms, where each notch serves to receive the anchor stone, and in the same step e) involves milling a rough shape of the fork. Step f) involves correcting the notches and forks using a broaching tool, Step g) involves laser blanking the obtained ankle to the remaining thickness of the strip to separate the ankle from the strip. Includes.

[0008] According to other advantageous modifications of the present invention, In step f), broaching is performed only in the axial direction. In step f), at least two lateral passes are made to create a specific width. In step e), the shaft hole and dart hole are also drilled. In step e), the milling is performed across the entire thickness of the strip. The method includes step h) attaching the anchor stone and axle to the anchor. The broaching tool is made of hard metal.

[0009] The present invention also relates to an anchor for an escapement system obtained using the method according to the present invention. [Brief explanation of the drawing]

[0010] Other features and advantages of the present invention will become apparent from the following detailed description with reference to the accompanying drawings. [Figure 1] An ankle obtained by the method according to the present invention is shown. [Figure 2] The steps in the manufacturing method according to the present invention are shown. [Figure 3] The steps in the manufacturing method according to the present invention are shown. [Figure 4-4a] The steps in the manufacturing method according to the present invention are shown. [Figure 5-5a] The steps in the manufacturing method according to the present invention are shown. [Figure 6-6a] The steps in the manufacturing method according to the present invention are shown. [Modes for carrying out the invention]

[0011] The present invention relates to a method for manufacturing an anchor for an escapement system.

[0012] Ankle 1 generally comprises a rod 2 formed from a metallic material which may be, for example, carbon steel (e.g., 20AP, 15P, Ck75, or Ck101), titanium, aluminum, austenitic cobalt-based alloys, brass alloys (e.g., CuZn42), or copper alloys (e.g., CuBe2 or German silver (CuNi1820)).

[0013] Rod 2 comprises arms 20 and 21 provided to support the anchor stone so as to engage with at least one escape wheel (not shown) in the escapement system. Between these two arms 20 and 21, an anchor shaft is fitted into a hole 22 for pivotally mounting the anchor 1. Finally, at the opposite ends of arms 20 and 21, rod 2 comprises a fork 5 having two horns 50 and 51.

[0014] The example shown in Figure 1 illustrates a conventional anchor for a watch. Naturally, other types of anchors, such as side anchors, can also be manufactured using the methods described below.

[0015] Next, the ankle manufacturing method 1 according to the present invention will be described with reference to Figures 2 to 6a.

[0016] The first step a) of the method shown in Fig. 2 consists of preparing a strip 10 of metal or metal alloy with a thickness e, in which guide holes 11 are punched to guide and move the strip 10 along a conveyor (not shown).

[0017] The next step b) shown in Fig. 3 consists of machining the strip 10 by milling, the milling 12 being carried out to a depth less than the thickness e of the strip and at least half of the thickness e of the strip to form the horns 50, 51 of the ankle.

[0018] The third step c) of the method shown in Figs. 4 and 4a consists of creating a bevel to form the body of the ankle, the first end of which includes the horns 50, 51 and the second end of which includes the two arms 20, 21. The bevel is created to a depth equal to half of the thickness e of the strip so that the body of the ankle remains attached to the strip at the end of the step.

[0019] The fourth step d) of the method consists of milling the outer shell of the ankle body, the milling also being carried out to a depth less than the thickness e of the strip and at least 2 / 3 of the thickness e of the strip to keep the ankle body attached to the strip.

[0020] The fifth step e) shown in Figs. 5 and 5a consists of roughing the cutouts 3, 4 in each of the arms 20, 21 and roughing the fork 5 in the same step. In this step, the cutouts 3, 4 and the fork 5 are milled over the entire thickness e of the strip 10. In step e), the shaft hole 22 and the dart hole 23 are also drilled.

[0021] The sixth step f) shown in Figure 6 consists of modifying the notches 3 and 4 and the fork 5 using a broaching tool. Broaching is performed only in the axial direction, and at least two lateral passes are made to produce the desired width of the notches 3 and 4. Such steps allow the desired angle to be obtained at the back of the notch, because milling would not be able to produce the desired angle due to the large radius of the milling machine.

[0022] Finally, step 7(g) consists of laser blanking the resulting ankle to the remaining thickness of the strip to separate the ankle from the strip. Alternatively, the ankle can be separated from the strip using a cutting machine.

[0023] The method may also include the step (h) of attaching the anchor stone and axle to the anchor.

[0024] The present invention also relates to an ankle obtained by the method according to the present invention.

Claims

1. A method for manufacturing an anchor (1) for an escapement system, Step a) prepare a strip (10) of metal or metal alloy having a thickness (e), and form guide holes (11) in the strip (10) to guide the strip, Step b) to form the horns (50, 51), by milling (12) the strip (10) over at least half of the thickness (e) of the strip (10), Step c) creating a bevel to form the body (2) of the ankle, the first end of which includes the horns (50, 51) and the second end of which includes two arms (20, 21), the step c) creating a bevel over at least half the thickness (e) of the strip so that the body of the ankle remains attached to the strip, Step d) is to mill the outer shell of the ankle body (2), wherein the milling is performed over 2 / 3 of the thickness (e) of the strip, Step e) is to mill the arms (20, 21) to roughly shape notches (3, 4) over the entire thickness (e) of the strip, wherein each of the notches (3, 4) serves to receive the anchor stone, and in the same step e) is to mill the fork (5) to roughly shape it. Step f) involves correcting the notches (3, 4) and the fork (5) using a broaching tool, Step g) to laser blank the obtained ankle to the thickness of the remaining strip and separate the ankle from the strip. A method characterized by including the following.

2. The method for manufacturing an ankle according to claim 1, characterized in that in step f), the broaching is performed only in the axial direction.

3. Ankle manufacturing method (1) according to claim 1, characterized in that in step (f), at least two lateral passes are made to produce a specific width.

4. The method for manufacturing an ankle according to claim 1, characterized in that in step (e), the shaft hole (22) and the dart hole (23) are also drilled.

5. The method for manufacturing ankle (1) according to claim 1, characterized in that in step (e), the milling is performed over the entire thickness of the strip.

6. An ankle manufacturing method (1) according to claim 1, characterized by including a step (h) of attaching the ankle stone and staff.

7. The method for manufacturing an ankle according to claim 1, characterized in that the broaching tool is made of hard metal.

8. An ankle (1) obtained by the method described in claim 1.

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