RETRACTABLE WATCH CROWN

Abstract

The invention relates to a crown for a watch component, said crown being intended to be connected to a winding stem of the watch mechanism, said crown comprising a tube (14) fixed to the watch case in alignment with the winding stem, a head (16) manipulated by a user and configured to move rotationally around the tube (14) and longitudinally relative to the tube (14), a sleeve (18) extending longitudinally and fixed to the head (16), and a piston (12) intended to be fixed to the winding stem and housed within the sleeve (18). The tube (14) has radial pins (22), and said head (16) has a cam track (24) cooperating with the pins (22), said cam track (24) defining at least one retracted position and one extended position, and the cam track (24) is carried by a ring mounted for rotation and translation with clearance around the tube (14). [Fig. 2]

Description

Title of the invention: RETRACTABLE WATCH CROWN TECHNICAL FIELD AND PREVIOUS ART

[0001] The present invention relates to a retractable watch crown, such as a winding crown, and to a timepiece comprising such a crown.

[0002] A watch crown is generally located on the side of the watch case and mechanically cooperates with the mechanical watch movement housed within the case to wind the mainspring and / or to set the time. The crown is connected to the mechanical watch movement in a known manner. It comprises a tube for fixing within the watch case, a head for grasping by the watch user to operate the mechanical movement, a sleeve kinematically connecting the head to a piston fixed to the winding stem of the mechanical movement, and elastic means disposed within the sleeve, compressed between the head and the piston, and exerting a restoring force by pulling the head and piston apart. The elastic means eliminate play and ensure the correct positioning of the piston / sleeve connection.

[0003] The crown can take several positions relative to the watch case, including a retracted position in which it is close to the watch case, and at least one extended position in which its rotation allows, for example, the setting of the time or the winding of the mainspring.

[0004] The connection between the crown and the mechanical movement is obtained, for example, by a clutch between the sleeve and the piston.

[0005] We wish to create a retractable crown. An example of a retractable crown mechanism is known from document CH 703 455; however, its construction is relatively complex. Indeed, it comprises pins mounted to slide transversely and returned to position by means of elastic means. Description of the invention

[0006] It is therefore one of the aims of the present application to provide a retractable crown mechanism for a watch part of simplified realization.

[0007] The stated objective is achieved by a retractable crown mechanism comprising a tube for attachment to a watch case, a crown including a head for manipulation by the user and a ring mounted for rotation and translation with clearance around the tube, and a piston of a mechanical movement for attachment to the mechanical movement. The tube includes at least one pin projecting radially from its lateral face, and the ring includes a cam track receiving at least one pin. The cooperation of the pin and the cam track allows the head to assume its various axial positions. Elastic means are provided between the head and the piston, tending to move them away from each other.

[0008] Thanks to the invention, the retractable crown mechanism is simplified and the number of parts used is reduced.

[0009] Preferably, the ring comprises three parts, a first part defining an axial end of the cam track, a second part defining another axial end of the cam track and a third part ensuring the axial and rotational immobilization of the first part and the second part.

[0010] Preferably, the mechanism comprises four pins distributed regularly around the axis of the tube and ensuring symmetrical guidance of the crown head.

[0011] It will be understood that the present invention is not limited to a number of pawns; the invention may include one, two, three or four pawns, or even more.

[0012] In other words, an intermediate element is inserted between the head and the tube to fix the axial positions of the crown relative to the tube, this intermediate element not intervening in the rotational movement of the crown.

[0013] The present invention then relates to a crown intended to be placed on a watch case comprising a watch mechanism, said crown being intended to be connected to a winding stem of the watch mechanism, said crown having a longitudinal axis comprising a tube intended to be fixed on the watch case in alignment with the winding stem, a head intended to be manipulated by a user, and configured to move in rotation around the tube and longitudinally relative to the tube, a sleeve extending longitudinally and fixed to the head, a piston intended to be fixed to the winding stem and housed in the sleeve, means for ensuring rotational locking of the piston and the sleeve, elastic means for separating the sleeve and the piston.The tube has at least one pin projecting radially outwards and said head has a cam track configured to cooperate with the at least one pin, said cam track defining at least one retracted position and one extended position, and the cam track is carried by a ring mounted for rotation and translation with clearance around the tube and in the head.

[0014] For example the head comprises a cylindrical body with a circular cross-section, a bottom closing one end of the body and the ring is mounted between the bottom and a radial projection of the body.

[0015] Preferably, the ring comprises two axial portions and a casing, one axial portion being on the bottom side and the other axial portion being on the opposite side of the bottom, each carrying an edge of the cam track, and the casing joining the two axial portions. The edge of the cam track of the axial portion on the opposite side of the bottom may open into an axial end on the opposite side of the bottom, defining the exit position.

[0016] The envelope and the two axial parts advantageously comprise means for angular indexing of the two axial parts.

[0017] The two axial parts can be machined and turned parts and be welded to the casing.

[0018] For example, the tube has four pins, each cooperating with a portion of the cam track.

[0019] The invention also relates to a timepiece comprising a watch case, a timepiece mechanism equipped with a winding stem and a crown according to the invention, the piston being fixed to the winding stem.

[0020] The watch mechanism can be configured so that the crown can take a stem-pulled position beyond the out position.

[0021] The invention also relates to a method for assembling the crown according to the invention, comprising: - Inserting the piston into the sleeve, - the installation of elastic means in the sleeve, supported at one end by the piston, - the fixing of the base onto the sleeve, - the insertion of the ring into the body, - the integration of the body and the foundation, - the placement of the head around the tube. Brief description of the drawings

[0022] This application will be better understood with the aid of the following description and the attached drawings, in which: [Fig. 1] is a side view of an example embodiment of a retractable crown mechanism according to the invention, with the crown in the raised position, [Fig.2] is a longitudinal cross-sectional view of the mechanism of [Fig.1], [Fig.3] is an exploded view of the mechanism of [Fig.1], [Fig.4] is a partially torn view of the mechanism of [Fig.1] showing the cooperation between a pin and the cam track, [Fig. 5] is a partially torn view of the mechanism according to the invention in a retracted position, [Fig.6] is a longitudinal sectional view along a plane orthogonal to the sectional plane of figures 4 and 5 of the mechanism according to the invention, the crown being in the retracted position. [Fig.7] is a longitudinal cross-sectional view along a plane orthogonal to the cross-sectional plane of figures 4 and 5 of the mechanism according to the invention, the crown being in an intermediate position, [Fig. 8] is a longitudinal sectional view along a plane orthogonal to the sectional plane of Figures 4 and 5 of the mechanism according to the invention, with the crown in the extended position; [Fig. 9] is a longitudinal sectional view along a plane orthogonal to the sectional plane of Figures 4 and 5 of the mechanism according to the invention, with the crown in the extended stem position. [Fig.10] is a bottom view of the retractable crown mechanism of [Fig.1], [Fig.11] is a front view of a timepiece comprising a retractable crown mechanism according to the invention. DETAILED DESCRIPTION OF IMPLEMENTATION METHODS

[0023] In the description that follows, a proximal element means an element located or oriented towards the watch case and a distal element means an element located away from or oriented away from the watch case.

[0024] Figures 1 to 11 show an example of an embodiment of a retractable or telescopic crown C for a timepiece, for example, a wristwatch 2. Figure 11 shows an example of a timepiece comprising such a crown C. The timepiece comprises a watch case 4, a dial, hands (not shown), a crystal 8, and a watch movement (not visible) located within the watch case. For example, the crown is received in a recess formed in a side face of the watch case.

[0025] The crown C includes a mechanism allowing the crown to be removed from the recess and made accessible to the wearer.

[0026] The crown has the function of allowing action on the clock mechanism by manipulating the crown when the crown is in a certain axial position, hereafter referred to as the out position, for example to set the hours and minutes and / or wind the mainspring of the clock mechanism.

[0027] The crown C extends along the longitudinal axis Y, which is orthogonal to the axis X of the timepiece. The crown includes a piston 12 for attachment to the winding stem (not shown) of the timepiece mechanism by a proximal end 12.1. In this example, the proximal end 12.1 has an axial hole for attachment to the winding stem. The crown also includes a tube 14 for attachment to the watch case 4 at the point where the winding stem passes. The tube 14 is attached to the watch case, for example, by gluing or screwing. The crown includes a head 16 that allows manipulation of the crown C. In the example shown, the head 16 has grooves 17 on its lateral face to facilitate manipulation of the head 16.

[0028] In the example shown, and advantageously, the head 16 is made in at least two parts: a body 16.1 forming the lateral part of the head and generally bearing grooves, and a base 16.2 which generally bears a symbol representative of the watch manufacturer, for example made on an added part 16.3 (figures 2 and 3). Alternatively, the case back is made in several parts, for example if one wishes to add a part bearing a particular symbol.

[0029] The body 16.1 has a generally cylindrical shape of revolution bearing on its outer lateral face grooves 17, closed at its distal end by the bottom 16.2 and having at its proximal end an annular projection 44. The function of the annular projection 44 will be described below.

[0030] The crown comprises a sleeve 18 fixed to the head 16 and extending along the Y-axis. The sleeve has a substantially cylindrical shape of revolution mounted to slide around the piston 12. Furthermore, the proximal end of the sleeve 18 and the lateral wall of the piston 12 are configured to allow rotational locking with each other, at least when the crown C is in the extended position. In this example, the inner lateral face of the sleeve 18 at its proximal end 18.1 has a polygonal shape cooperating with a polygonal shape of the outer lateral face of the piston 12, thus ensuring rotational drive of the piston 12 by the sleeve 18.

[0031] Alternatively, a clutch system is provided between the piston and the sleeve, ensuring their rotational locking when the head is away from the watch case. The clutch system comprises, for example, polygonal shapes carried by the sleeve and the piston that cooperate with each other when the head is away from the watch case. When the head is close to the watch case, the polygonal shapes are separated, and the sleeve and the piston are then not rotationally locked. Any other means of rotationally locking the sleeve and the piston according to their relative axial position falls within the scope of the present invention.

[0032] Elastic means tending to move the head 16 away from the piston 12 are interposed between the head and the piston 12. In the example shown the elastic means comprise a helical spring R mounted in the sleeve 18 in support between the head and the piston 12.

[0033] Sealing means are also provided to protect the inside of the watch case. In the example shown, the sealing means comprise three O-rings 19 between the outer side face of the sleeve 18 and the inner side face of the tube 14.

[0034] The crown C also includes a cam system 20 between the head 16 and the tube 14 allowing the movement of the head 16 along the Y axis and the activation / deactivation of the connection system.

[0035] In the example shown, the cam system 20 comprises four pins 22 extending radially outwards from the outer lateral face of the tube 14, as can be seen in [Fig. 6]. The four pins 22 are diametrically opposed two The two pins 22 are arranged at 90° to each other. The pins 22 form the cam follower. The use of four pins 22, regularly spaced at an angle, ensures balanced guidance of the head 16; however, the number and arrangement of the pins are not limiting. The system could therefore include a single pin, two diametrically opposed pins, or three pins, for example, without departing from the scope of the present invention.

[0036] The cam system 20 includes a cam track 24 or cam profile which is fixed in movement to the head 16.

[0037] The cam track 24 is configured so that, in a first cooperation configuration between the pins 22 and the cam track 24, the head 16 is in the first axial position and, in a second cooperation configuration between the pins and the cam track 24, the head 16 is in the second axial position.

[0038] The crown C includes a ring 26 mounted around the tube 14 and carrying the cam track 24. The ring 26 is free to rotate about the Y-axis and relative to the fixed tube 14 carrying the pins, and relative to the head, which can only rotate if a torque is applied to it by the user. The ring 26 is a free-running ring. It is mounted with rotational and translational clearance around the tube and within the head.

[0039] The cam track is partly visible in figures 4 and 5.

[0040] The cam track is delimited by a proximal edge 24.1 and a distal edge 24.2, between which the 22 pawns are guided.

[0041] In the example shown ([Fig.3]), the ring 26 comprises a first part 26.1, one longitudinal end of which forms the proximal edge 24.1 and a second part 26.2, one longitudinal end of which forms the distal edge 24.2.

[0042] Furthermore, the path comprises, for each pin, a lower position PB or retracted position, in which the head 16 is in the first axial position, a higher position PH or extended position, in which the head 16 is in the second axial position, and intermediate positions PII, PI2 allowing passage from the first axial position to the second axial position and vice versa. The intermediate positions are on the distal side of the ring.

[0043] The cam track has the same profile four times, each extending over an angle of 90° around the Y axis. Thus each pin follows a cam profile identical to that of the other pins.

[0044] Since the pins 22 are supported by the tube 14, which is intended to be fixed to the watch case, it is the cam track, and therefore the ring 26, that move in rotation around the Y-axis and in translation along the Y-axis. We will designate the direction of rotation of the cam track as the "direction of actuation." In the example shown, the direction of actuation is clockwise. The cam track and the ring can only rotate in the direction of actuation.

[0045] The positions are delimited by two portions of longitudinal edge configured to form a cradle for each pawn.

[0046] The positions PB, PH, PII, PI2 are angularly offset from each other so that with each movement of the head along the Y axis, the ring pivots and the pins are received in another position.

[0047] The path includes ramps connecting the positions, the ramps are formed by portions of the proximal edge 24.1 and distal edge 24.2 having an inclination with respect to the Y axis.

[0048] In this example, the upper position PH is laterally delimited by two proximal edge portions 28.1, 28.2 parallel to the Y-axis and opening into the distal end of the proximal part. The two edge portions then form a stop for the pin in both directions of rotation. The axial length of the portions 28.1, 28.2 is chosen to be sufficiently large so that the pins are always located between the two portions 28.1, 28.2 regardless of the position of the ring along the Y-axis.

[0049] The lower position PB is laterally delimited on one side by a proximal edge portion 30.1 parallel to the Y-axis and forming a stop in the direction of actuation, and on the other side by a ramp portion 30.2 with a proximal edge inclined towards the proximal end in the direction of actuation. Furthermore, the intermediate position comprises a base 30.3 perpendicular to the Y-axis.

[0050] The intermediate position PII is delimited at its distal edge by two ramps RI, R2 inclined towards each other. The intermediate position PI2 is delimited by a portion 32.1 parallel to the Y-axis downstream and by a portion of ramp 32.2 upstream, the portion of ramp 32.2 being inclined towards the distal end. In this example, a bottom 32.3 perpendicular to the Y-axis connects portion 32.1 and portion 32.2.

[0051] The cam track configuration for defining the different positions PB, PH, PII, PI2 is in no way limiting. Indeed, it is possible to consider that the lower position has no bottom or that the intermediate position PII has a bottom.

[0052] The intermediate positions PII, PI2 are angularly offset from the low and high positions so that, considering the direction of actuation, the pin 22 successively encounters the low position PB, the intermediate position PII, the high position PH and the intermediate position PI2.

[0053] The distance along the Y axis between the high position PH and the low position PB is such that it allows connection and disconnection between the sleeve and the piston.

[0054] As explained above in this example, and advantageously, the ring 26 is made in three parts: the first distal part 26.1, the second proximal part 26.2, and a casing 26.3 surrounding parts 26.1 and 26.2 and joining the two parts 26.1 and 26.2. This three-part design allows for simplified manufacturing of the ring 26. The elements are, for example, produced by machining and machining, then welded for example by laser welding to each other. The first part has an annular surface 37 projecting radially outwards and intended to bear against the annular projection 44 of the head, the annular surface 37 is located axially on the first part so that the ring 26 extends outside the head towards the box to form a housing for the pins 22 regardless of the axial position of the head.

[0055] Alternatively, the ring 26 is a single piece and is obtained by machining. Alternatively, the ring 26 is produced in a single piece by 3D printing.

[0056] Preferably, and as is particularly visible in [Fig. 3], the ring 26 comprises angular and axial indexing means between the proximal part 26.2, the distal part 26.1, and the casing 26.3 so that, during assembly of the ring, the proximal edges 24.1 and distal edges 24.2 are correctly positioned angularly and axially relative to each other. In the example shown, the proximal part 26.2 comprises a tubular portion 36 with axis Y carrying the edge 24.1 of the cam track 24 and a crown 38 extending radially at the distal and proximal ends. The crown 38 comprises two diametrically opposed lugs 40 extending along the Y axis and cooperating with notches 42 formed in the proximal longitudinal end of the casing 26.3; the distal part 26.1 comprises a tubular part with axis Y bearing at one end the edge 24.2 of the cam track 24 and at the other end of the lugs 37 cooperating with notches 42 formed in the distal end of the casing 26.3. Thus, the position of the distal and proximal parts relative to each other is fixed. Preferably, the lugs 40 are angularly aligned with two high positions facilitating their manufacture. Alternatively, a single lug per proximal and distal part can be used. Alternatively still, the lugs are part of the casing.

[0057] In the example shown, the envelope 26.3 has side windows 46, but the implementation of a solid envelope does not fall outside the scope of the present invention.

[0058] An example of a method for assembling the retractable crown mechanism will now be described.

[0059] The elements of the ring 26 are pre-assembled.

[0060] The piston 12 is mounted in the sleeve 18.

[0061] The spring R is then mounted around the piston 12 in the sleeve 18 and the bottom 16.2 of the head 16 is fixed to the sleeve and piston assembly so as to compress the spring.

[0062] The ring 26 is then mounted in the body 16.1 bearing against the annular projection.

[0063] The base 16.2 is then secured to the body 16.1, so that the ring 26 is retained with axial play and radial play in the head between the base 16.2 and the annular projection 44.

[0064] The different elements are joined together by welding or gluing. A sub-assembly is thus formed.

[0065] The seals 19 are mounted in the tube 14, and the tube 14 is fixed to the watch case. The subassembly is then inserted onto the tube so as to allow the pins to enter the cam track. The pins 22 are oriented angularly so as to be positioned at a high point between two proximal edge portions 28.1, 28.2; the pins 22 then slide between the two proximal edge portions 28.1, 28.2. The piston is secured to the winding stem of the watch mechanism.

[0066] The operation of the retractable crown system will now be described.

[0067] The operation will be described starting from the first position, in which the Pins 22 are housed in the upper position PH, as can be seen in [Fig.4] and [Fig.8]. In this position, the crown C is in a position away from the watch case.

[0068] The user exerts an axial force on the head along the Y-axis towards the watch case against the restoring force of the spring. Each pair of proximal edge portions 28.1, 28.2 slides on either side of a pin 22.

[0069] Beyond a certain stroke in the Y direction, each pin 22 encounters the ramp portion 32.2. Due to the inclination of the ramp portion 32.2 and the cooperation between the ramp portion and the fixed pin, the ring 26 pivots clockwise until the base 32.3 comes into contact with the pin 22.

[0070] The user releases their pressure on the crown, which, under the effect of the spring's return force, moves away from the watch case. Portion 30.2 encounters pin 22, forcing the ring to pivot clockwise until portion 30.1 comes into contact with pin 22. The crown reaches its lower position, known as the retracted position (Figures 5 and 6).

[0071] When the user wishes to operate the watch mechanism, for example to wind the mainspring or set the time, the user applies force to the crown towards the watch case against the return spring. The ramp R2 engages the pin 22, which, due to their interaction, forces the ring to pivot clockwise ([Fig. 7]). The user releases the force, and then the ramp RI comes into contact with the pin 22. The ring 26 pivots and slides axially until the pin 22 is located between the proximal edge portions 28.1, 28.2 in the raised or extended position. The sleeve 18 has moved along the Y-axis away from the watch case ([Fig. 8]). In this position, when The user rotates the crown, thus acting on the clockwork mechanism to wind the mainspring.

[0072] For example, in this extended position, it can also act on the hands if the watch only has one position for the crown.

[0073] The user can then apply a pulling force to the crown from its extended position to reach a pulled stem position, to axially move the winding stem and allow access to other functions of the clockwork mechanism, for example, for setting the time. In this position, the pins are still received in the ring 26. This position is shown in [Fig. 9].

[0074] The ring 26 controls the axial position of the crown and the rotational position of the crown is fixed by the user's manipulation.

[0075] The axial stroke of the head for moving from one position to another can be adjusted according to the geometry of the cam path. For example, the stroke is from 0.8 mm to 1 mm.

[0076] Alternatively, it is possible to consider that the crown has several positions with the stem pulled out, one position for setting the time and one position to allow the adjustment of a complication.

[0077] As a further alternative, it may be envisaged that the crown does not have a stem-pulled position, and that the crown-out position allows the time to be set, for example in the case of a quartz or self-winding watch.

[0078] It can also be envisaged that a function of the watch may be attainable with the crown in the retracted position.

[0079] The crown according to the invention is simplified in its construction compared to retractable crowns of the prior art.

Claims

Demands

1. A crown intended to be fitted to a watch case comprising a watch mechanism, said crown being intended to be connected to a winding stem of the watch mechanism, said crown having a longitudinal axis (Y) comprising: - a tube (14) intended to be fixed to the watch case in alignment with the winding stem, - a head (16) intended to be manipulated by a user, and configured to move in rotation around the tube (14) and longitudinally relative to the tube (14), - a sleeve (18) extending longitudinally and fixed to the head (16), - a piston (12) intended to be fixed to the winding stem and housed in the sleeve (18), means for ensuring rotational locking of the piston (12) and the sleeve (18), elastic means for separating the sleeve (18) and the piston (12),wherein the tube (14) has at least one pin (22) projecting radially outwards and said crown has a cam track (24) configured to cooperate with the at least one pin (22), said cam track (24) defining at least one retracted position (PB) and one extended position (PH), and wherein the cam track (24) is carried by a ring (26) mounted for rotation and translation with clearance around the tube (14) and in the head (16).

2. Crown according to claim 1, in which the head comprises a body (16.1) of cylindrical shape with circular cross-section, a bottom (16.2) closing one end of the body and in which the ring (26) is mounted between the bottom (16.2) and a radial projection (44) of the body (16.1).

3. Crown according to claim 1 or 2, in which the ring (26) comprises two axial parts (26.1, 26.2) and a casing (26.3), one of the axial parts being on the bottom side and the other axial part being on the opposite side of the bottom, each carrying an edge of the cam track (24) and in which the casing (26.3) secures the two axial parts (26.1, 26.2).

4. Crown according to claim 3, wherein the edge of the cam track of the axial part opposite the bottom opens into an axial end opposite the bottom defining the exit position.

5. Crown according to claim 3 or 4, wherein the envelope and the two axial parts comprise means for angular indexing of the two axial parts.

6. Crown according to claim 3, 4 or 5, wherein the two axial parts are machined and turned parts and are welded to the casing.

7. Crown according to any one of claims 1 to 6, wherein the tube has four pins (22), each cooperating with a portion of the cam track (24).

8. A timepiece comprising a watch case, a timepiece mechanism equipped with a winding stem and a crown according to any one of claims 1 to 7, the piston being fixed to the winding stem.

9. A timepiece according to claim 8, wherein the timekeeping mechanism is configured so that the crown can assume a stem-pulled position beyond the out position.

10. A method for assembling the crown according to any one of claims 1 to 7, comprising: - inserting the piston into the sleeve, - placing the elastic means in the sleeve supported by one end on the piston, - fixing the base on the sleeve, - placing the ring in the body, - securing the body and the base, - placing the head around the tube.

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