WO2019207490A1

WO2019207490A1 - Timepiece barrel and method for modifying a timepiece movement

Info

Publication number: WO2019207490A1
Application number: PCT/IB2019/053358
Authority: WO
Inventors: Didier VUILLEMIN; Marc-Antoine Sudan
Original assignee: Patek Philippe Sa Geneve
Priority date: 2018-04-26
Filing date: 2019-04-24
Publication date: 2019-10-31
Also published as: CH716092B1

Abstract

The invention relates to a timepiece barrel (100) of the fixed flange type, in which the hook (136) of the arbor (102) and the recess (140) in the internal cylindrical surface of the drum (104) are designed such that the mainspring (106) can be wound around the barrel arbor (102) inside the barrel drum (104) in one direction or the other. The invention also relates to a method for modifying a timepiece movement, comprising a step consisting in inverting the mainspring (106) inside the drum (104) of the barrel (100) of the movement in order to change the direction of rotation of the drum (104).

Description

Watch barrel and watch movement modification method

The present invention relates to a watch cylinder, in particular a barrel for a timepiece with manual winding, and a method of modifying a watch movement comprising such a barrel.

In a mechanical watchmaking movement, the barrel is the motor unit that provides the energy needed to move the various components. The barrel comprises a drum, a lid closing the drum, a shaft around which the drum and the lid rotate freely, and a spiral motor spring housed in the drum and wound around the shaft. The outer turn of the motor spring is held by the cylindrical wall of the drum. The shaft includes an intermediate portion called "bung" which carries a hook to which is attached the inner coil of the mainspring. The shaft is integral in rotation with a ratchet and, through it, can be rotated in a predetermined direction by a winding stem of the movement, in the case of a manual winding movement, or by an oscillating weight in the case of a self-winding movement, to arm the mainspring and thus accumulate energy. The mainspring disarms by rotating the drum in said predetermined direction, which drum, by a toothing it carries, drives the gear movement.

The hook that carries the barrel shaft is engaged in an eyelet of the inner coil of the mainspring. This hook generally has an asymmetric shape, with a hooking surface that retains the inner turn and a non-functional surface opposite to the hooking surface. The appended FIG. 1, issued from the patent application WO 2017/005394 of the present applicant, represents a top view of a barrel shaft 1 with its bung 3 and its hook 5, the attachment surface of the hook 5 being designated by 7, the inner coil retained by the attachment surface 7 being designated 9. This shaft 1 further comprises, upstream of the hook 5 in the winding direction of the mainspring, a clearance 1 1 intended to receive the end internal spring motor. Other barrel trees with Asymmetrical or symmetrical hooks are described in patent application CN 103376727.

To retain the outer turn of the motor spring, the inner surface of the cylindrical wall of the drum cooperates with a blade, called "flange" attached to the outer turn. This flange is generally fixed in the case of a manual winding movement and is slippery - it can temporarily disengage from the drum above a limit winding torque - in the case of a self-winding movement. The present invention relates in a preferred manner a fixed-flanged cylinder. Generally, in this type of barrel the cylindrical wall of the drum has a recess delimited in the circumferential direction by two opposite surfaces, one of which is a gripping surface which cooperates with the flange. The appended FIG. 2, taken from the book "Théorie d'horlogerie" by Ch. A. Reymondin et al., Editions of the Federation of Technical Schools, Switzerland, 1998 shows in exploded view such a barrel with its drum 13, its motor spring 15, its shaft 17 and its cover 19. As can be seen, the internal surface of the cylindrical wall of the drum 13 has a recess 21 adapted to receive the flange 23 fixed to the motor spring 15. An end surface 25 of the recess 21 is a hooking surface. The other end surface 27 is non-functional. Other fixed flanged drums are described in US 163161, US 753584 and US 381 176.

In order to increase the energy storage capacity in a mechanical clock movement, it is known to arrange several barrels in series, as shown schematically in Figure 3. However, these barrels do not all turn in the same direction. For example, the barrels 29 and 31 in Figure 3 turn clockwise while the intermediate barrel 33 rotates counterclockwise. This implies that the barrels can not all be identical and therefore leads to relatively high manufacturing and logistics costs. To remedy this drawback, it is possible to place references between the barrels so that they all turn in the same direction, as shown in FIG. 4 where the references are designated by 35, but this solution increases the number of components and congestion and decreases the yield.

There are other circumstances where the direction of rotation of the cylinder may be problematic. For example, when it is desired to modify the wheel of an existing movement, to add to it one or more additional functions or to increase the power reserve, the direction of rotation of the barrel may require the use of one or more referrals that will increase clutter and affect performance, or the replacement of the barrel by another turn in the other direction.

The present invention aims to provide a watch cylinder which facilitates the design, manufacture and / or modification of watch movements.

To this end, it is proposed a fixed-flange type watch cylinder comprising a barrel drum, a barrel shaft, a motor spring wound around the barrel shaft in the barrel drum and a flange connected to a barrel. outer coil of the mainspring, the barrel drum having in its inner cylindrical surface a recess for receiving the flange, the recess being delimited in the circumferential direction of the barrel drum by first and second opposed hooking surfaces, the first gripping surface for retaining the flange if the mainspring is wound in the barrel drum in a predetermined direction, the second gripping surface for retaining the flange if the mainspring is wound in the barrel drum in a direction opposite to the predetermined direction, the barrel shaft comprising a hook engaged in an eyelet of an inner turn of the mainspring, the hook c omprenant third and fourth gripping surfaces opposite in the circumferential direction of the barrel shaft, the third gripping surface for retaining the inner turn if the mainspring is wound around the barrel shaft in the predetermined direction , the fourth attachment surface for retaining the inner turn if the spring motor is wrapped around the barrel shaft in the opposite direction to the predetermined direction.

The present invention further provides a method of modifying a watch movement, the watch movement comprising a barrel as defined above, characterized in that it comprises a step of turning the mainspring in the drum barrel so to change the direction of rotation of the latter.

The present invention also proposes a method for modifying a watch movement, the watch movement comprising a barrel itself comprising a barrel drum, a barrel shaft and a motor spring wound around the barrel shaft in the barrel of the barrel. barrel, the motor spring being mountable in the barrel drum being wound in one direction or the other, characterized in that it comprises a step of turning the mainspring in the barrel drum to change the direction rotation of the latter.

Other characteristics and advantages of the present invention will appear on reading the following detailed description, made with reference to the appended drawings in which:

Figure 1, already commented, is a plan view from above of a barrel shaft according to the state of the art, which is attached an inner coil of a motor spring (shown partially); Figure 2, already discussed, is an exploded perspective view of a barrel according to ^the prior art;

Figures 3 and 4, already commented, schematically show two barrel arrangements in series according to the state of the art;

Figure 5 is a sectional view of a cylinder according to the invention; Figure 6 is a perspective view of the shaft of the cylinder according to the invention; Figure 7 is a bottom plan view of the barrel shaft according to the invention;

Figure 8 is a bottom plan view of a variant of the barrel shaft according to the invention;

Figure 9 is a perspective view of the barrel drum according to the invention;

Figure 10 is a plan view from above of the barrel drum according to the invention;

Figure 11 is a plan view from above of the cylinder according to the invention without its cover and with its motor spring wound in the drum in a first direction;

Figure 12 is a plan view of the cylinder according to the invention without its cover and with its motor spring wound in the drum in a second direction opposite to the first.

In the rest of this description, the terms "cylinder" and "cylindrical" will refer to cylinders of revolution.

With reference to FIG. 5, a barrel 100 with a fixed flange according to a particular embodiment of the invention, for the movement of a mechanical timepiece with manual winding, such as a wristwatch or a wristwatch. pocket, comprises a barrel shaft 102, a barrel drum 104, a spiral motor spring 108 housed in the barrel drum 104 and a lid 108.

The barrel drum 104 comprises a bottom 110, a cylindrical wall 112 and a peripheral toothing 114. The cover 108 closes the barrel drum 104 on the opposite side to the bottom 110 being fixed to the cylindrical wall 112. In a variant, the cover 108 can be omitted.

With reference to FIGS. 5 to 7, the barrel shaft 102 extends along an imaginary axis A and is terminated at its ends, in known manner, respectively by a lower pivot 116 and a section of square section 118. lower pivot 118 is intended to rotate in a frame member of the movement, typically platinum. The section of square section 1 18 is intended to engage in a central hole of corresponding shape of a ratchet not shown in the figures for securing in rotation the barrel shaft 102 and the ratchet. The ratchet allows rotating the barrel arbor 102 about the axis A, through a winding stem operable by ^the user, in order ^to arm the power spring 106 and thus accumulate in the mechanical energy in the barrel 100.

Between its two ends 1 16, 1 18 the barrel shaft 102 comprises in a known manner, successively, a cylindrical section 120 traversing and rotating in rotation about the axis A the bottom 1 10 of the barrel drum 104, a portion of larger section constituting the bung 122, a cylindrical section 124 traversing and guiding in rotation about the axis A the cover 108 and a cylindrical section 126 for pivoting in a frame member of the movement, typically a bridge.

The surface of the bung 122, designated by 128, is the one around which the internal coil of the motor spring 106 winds and rests. In the example illustrated (see FIG. 7), this surface 128 comprises a cylindrical part 130 of radius R1 extending over a first angle, typically greater than 180, a cylindrical portion 132 of radius R2 extending over a second angle, typically less than 180 °, where R2 is greater than R1, and connecting portions 134 connecting the cylindrical portions 130, 132 together. The surface 128 of the bung 122 could however have another shape.

From the surface 128, more precisely from the cylindrical portion 130 of radius R1 and in the zone opposite to the cylindrical portion 132, a hook 136 engages in an eyelet 138 (visible in FIG. 5) of the inner coil of the mainspring 106 to secure this inner coil to the barrel shaft 102. The hook 136 includes two opposite end surfaces 136A and 136B in the circumferential direction of the shaft 102. A clearance can be provided in the surface 128 immediately upstream and or downstream of the hook 136 in said circumferential direction, like the clearance 11 of FIG. 1. The opposite end surfaces 138A and 136B may be planar, as shown in FIG. 7, or concave, as shown in FIG. 8. In either case, each end surface 136A, 136B is a gripping surface in FIG. this direction for example that it forms a right or acute angle with a cylinder (imaginary) axis A and passing through the base (junction points with the surface 128) of the surface 136A, 136B In the example shown, the cylindrical portion 130 of radius R1 of the surface 128 of the bung 122 coincides with a portion of this cylinder. In the case of concealed attachment surfaces 138A, 136B, the angle α is measured between the average tangent plane to the surface 136A, 136B and the cylinder. For each attachment surface 136A, 136B, the angle a is preferably less than 87 °, more preferably less than 85 °, more preferably less than 83 °, more preferably less than 81 °. Preferably, to facilitate manufacture, the two attachment surfaces 136A, 136B are symmetrical to each other with respect to a plane P1 containing the axis A. Preferably, the hook 138 as a whole or the bung 122 as a whole is symmetrical with respect to plane P1.

The barrel shaft 102 can thus be used indifferently with the motor spring 106 wound in one direction or the other. With the motor spring 106 wound in a first direction, it is the attachment surface 136A which retains the inner turn, that is to say prevents it from sliding on the bung 122, cooperating with the wall of the eye 138, and which causes this inner turn during the winding of the mainspring 106. With the motor spring 106 wound in a second direction opposite the first, it is the hooking surface 138B which retains the inner coil cooperating with the wall of ^the eyelet 138 and which drives the inner coil during the winding of the motor spring 106.

Figures 9 and 10 illustrate the barrel drum 104 with its bottom 1 10, its cylindrical wall 1 12 and toothing 1 14. The inner face of the cylindrical wall 1 12 has a recess 140 for fixing the outer coil of the mainspring 106 to the wall 1 12 via a flange 142 (visible in Figure 1 1 and similar to the flange 23 of Figure 2) itself even fixed in a known manner by one of its ends at the end of the outer turn. The recess 140 is preferably in the form of a circular arc centered on the axis A and is sufficiently large to be able to accommodate the entire flange 142 when the mainspring 106 is disarmed. The recess 140 is delimited in the radial direction by a bottom 140C and in the circumferential direction by two opposite surfaces 140A, 140B.

Both surfaces 140A, 14GB may be flat, as shown, or concave. They constitute hooking surfaces in this sense, for example that they each form a right or acute angle b with an (imaginary) cylinder of axis A and passing through the base (junction points with the bottom 140C) of the surface 140A, 140B. In the example shown, the bottom 14QC of the recess 140 coincides with a part of this cylinder. In the case of concealed attachment surfaces 140A, 140B, the angle b is measured between the average tangent plane to the surface 140A, 14QB and the cylinder. For each attachment surface 140A, 140B, the angle b is preferably less than 87 °, more preferably less than 85 °, more preferably less than 83 °, more preferably less than 81 °. Preferably, to facilitate manufacture, the two attachment surfaces 140A, 140B are symmetrical to one another with respect to a plane P2 containing the axis A, the plane P2 may or may not coincide with the plane P1. Preferably, the recess 140 as a whole or even the drum 104 as a whole is symmetrical with respect to the plane P2.

The drum drum 104 can thus be used indifferently with the motor spring 106 wound in one direction or the other. With the motor spring 106 wound in a first direction, it is the attachment surface 140A which retains the flange 142, that is to say prevents it from sliding on the cylindrical wall January 12, cooperating with the free end of the flange 142, the attachment surface 140A being pushed by the flange 142 during the disarming of the mainspring 106. With the motor spring 106 wound in a second direction opposite to the first, it is the 14GB attachment surface who retains the flange 142 by cooperating with the free end thereof, and which is pushed by the flange 142 during the disarming of the mainspring 106.

Figures 1 1 and 12 show by way of illustration the cylinder 100 according to the invention with its mainspring 106, in a disarmed state, wound in two opposite respective directions.

The barrel 100 according to the invention, with its barrel shaft 102 and its barrel drum 104, is therefore able to operate in one direction of rotation or in the other depending on the winding direction chosen for the mainspring 106. This property facilitates the design, manufacture and modification of watch movements and timepieces.

It is indeed possible to arrange several barrels 100 in series by alternating the winding direction of the mainspring 106. As all the barrels are identical, except the winding direction of the mainspring 106, the manufacturing and logistics costs are reduced. In addition, it is not necessary to place references between the barrels, so that the size and performance are preserved.

It is also possible to start from a basic movement comprising the barrel 100 according to the invention and to modify it, for example to modify its gear. The modification of the gear train may comprise the addition of a intermediate or intermediate wheel between the barrel drum and the barrel. mobile which meshing with him, this return or intermediate mobile serving for example to distribute the driving force to the cogwheel and an additional gear supplying a complication or to increase the power reserve of the movement. In this case, it is necessary to reverse the direction of rotation of the barrel drum so that the needles continue to rotate in the right direction. Instead of replacing the barrel, the only possible solution in the state of the art, the present invention proposes to simply return the motor spring 106 in the barrel drum 104 so that it is wound in the other direction. The reversal of the direction of rotation of the barrel drum 104 requires only a few adaptations in the movement, such as flipping the ratchet ratchet. In another application of the invention, starting from a basic movement comprising the barrel 100 according to the invention, the motor spring 108 is turned back into the barrel drum 104 to reverse the direction of rotation of the latter, it rises the indicator hands on the bridge side instead of the platinum side and some other components such as the ratchet and the exhaust are turned over. This gives a movement that can be mounted in a timepiece, typically a wristwatch or a pocket watch, in a returned position relative to conventional timepieces, that is to say in a position where the bridge side is visible to the user (the timepiece does not include a dial or having a transparent dial), and this without replacing the barrel or change the structure of the movement.

Note that the principle, explained above, to return the mainspring to change the direction of rotation of the barrel drum can also be applied to movements whose barrel is slidable flange, particularly to movements with automatic winding .

Claims

he CLAIMS

A fixed flange type watch cylinder (100) comprising a barrel drum (104), a barrel shaft (102), a motor spring (106) wound around the barrel shaft (102) in the barrel drum (104) and a flange (142) connected to an outer turn of the motor spring (106), the barrel drum (104) having in its inner cylindrical surface a recess (140) for receiving the flange (142) the recess (140) being delimited in the circumferential direction of the barrel drum (104) by opposing first and second engaging surfaces (140A, 140B), the first engaging surface (140A) for retaining the flange (142) if the mainspring (106) is wound in the barrel drum (104) in a predetermined direction, the second hooking surface (140B) for retaining the clamp (142) if the mainspring (106) is wound in the barrel drum (104) in a direction opposite to the predetermined direction , the barrel shaft (102) comprising a hook (136) engaged in an eyelet (138) of an inner coil of the mainspring (106), the hook (136) comprising third and fourth hooking surfaces (136A , 136B) opposed in the circumferential direction of the barrel shaft (102), the third latching surface (136A) for retaining the inner coil if the motor spring (106) is wrapped around the barrel shaft ( 102) in the predetermined direction, the fourth hooking surface (136B) for retaining the inner turn if the drive spring (106) is wrapped around the barrel shaft (102) in the opposite direction to the predetermined direction.

2. Barrel (100) according to claim 1, characterized in that the first and second attachment surfaces (140A, 140B) are symmetrical to each other with respect to a plane (P2) containing the imaginary axis (A) the barrel drum (104).

3. Barrel (100) according to claim 1 or 2, characterized in that the first attachment surface (140A) and / or the second attachment surface (140B) are planar.

4. Barrel (100) according to claim 1 or 2, characterized in that the first attachment surface (140A) and / or the second attachment surface (140B) are concave.

5. Barrel (100) according to any one of claims 1 to

4, characterized in that each of the first and second attachment surfaces (140A, 140B) forms a right or an acute angle (b) with an imaginary cylinder having as its axis the imaginary axis (A) of the barrel drum (104) and passing through the base of said surface (140A, 140B).

Barrel (100) according to any one of claims 1 to

5, characterized in that the third and fourth hooking surfaces (136A, 136B) are symmetrical to one another with respect to a plane (P1) containing the imaginary axis (A) of the barrel shaft (102).

7. Barrel (100) according to any one of claims 1 to

6, characterized in that the third hooking surface (136A) and / or the fourth hooking surface (136B) are planar.

8. Barrel (100) according to any one of claims 1 to 6, characterized in that the third attachment surface (136A) and / or the fourth attachment surface (136B) are concave.

9. Barrel (100) according to any one of claims 1 to 8, characterized in that each of the third and fourth attachment surfaces (136A, 136B) forms an angle (a) right or acute with an imaginary cylinder having for axis the imaginary axis (A) of the barrel shaft (102) and passing through the base of said surface (136A, 136B).

10. Set of barrels arranged in series, each barrel (100) according to any one of claims 1 to 9, the winding direction of the mainspring (106) being inverted from one barrel to the next.

11. A method of modifying a watch movement, the watch movement comprising a barrel (100) according to any one of claims 1 to 9, characterized in that it comprises a step of turning the mainspring (106) in the barrel drum (104) to change the direction of rotation of the barrel.

12. A method of modifying a watch movement, the watch movement comprising a barrel (100) itself comprising a barrel drum (104), a barrel shaft (102) and a motor spring (106) wound around the barrel barrel shaft (102) in the barrel drum (104), the motor spring (106) being able to be mounted in the barrel drum (104) by being wound in one direction or the other, characterized in that it comprises a step of returning the mainspring (106) in the barrel drum (104) to change the direction of rotation thereof.

13. The method of claim 11 or 12, characterized in that it further comprises a step of modifying a train driven by the barrel drum (104) to for example add a function to the watch movement or increase the power reserve of the watch movement.

14. The method of claim 11 or 12, characterized in that it further comprises a step of mounting the indicator hands on the bridge side of the watch movement.