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 PRIOR 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 cooperates mechanically with the mechanical watch movement which is housed in the watch case, to wind the barrel spring and / or to set the time. The crown is connected to the mechanical watch movement in a known manner. It comprises a tube intended to be fixed in the watch case, a head which is intended to be grasped by the user of the watch to act on the mechanical movement, a sleeve kinematically connecting the head to a piston fixed on the winding stem of the mechanical movement, and elastic means arranged in the sleeve, compressed between the head and the piston and exerting a return force away from the head and the piston. The elastic means eliminate play and guarantee the correct position for the piston / sleeve connection.

[0003] The crown can take several positions relative to the watch case, in particular 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 barrel spring.

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

[0005] It is desired to produce a retractable crown. An example of a retractable crown mechanism is known from document CH 703 455, however this is relatively complex to produce. In fact, it comprises pins mounted to slide transversely and returned to position by means of elastic means. Presentation of the invention

[0006] It is therefore an aim of the present application to provide a retractable crown mechanism for a timepiece of simplified construction.

[0007] The aim stated above is achieved by a retractable crown mechanism comprising a tube intended to be fixed to a watch case, a crown comprising a head intended to be manipulated by the user and a ring mounted in rotation and in translation with play around the tube, a piston of a mechanical movement intended to be secured to the mechanical movement. Said tube comprises at least one pin projecting radially from its lateral face, and the ring comprising a cam path receiving the at least one pin. The cooperation of the pin and the cam path allows the head to take its different 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 delimiting an axial end of the cam path, a second part delimiting another axial end of the cam path 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 comprise 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 timepiece mechanism, said crown being intended to be connected to a winding stem of the timepiece mechanism, said crown of 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 attachment of the piston and the sleeve, elastic means so as to separate the sleeve and the piston.The tube comprises at least one pin projecting radially outwards and said head comprises a cam path configured to cooperate with the at least one pin, said cam path defining at least one retracted position and one extended position, and the cam path is carried by a ring mounted in rotation and in translation with play around the tube and in the head.

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

[0015] Preferably, the ring comprises two axial parts and an envelope, one of the axial parts being on the side of the bottom and the other axial part being opposite the bottom, each carrying an edge of the cam path and the envelope secures the two axial parts. The edge of the cam path of the axial part opposite the bottom may open into an axial end opposite the bottom defining the extended 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 path.

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

[0020] The timepiece mechanism may be configured so that the crown can assume a stem-pulled position beyond the extended position.

[0021] The invention also relates to a method of assembling the crown according to the invention, comprising: - inserting the piston into the sleeve, - the installation of elastic means in the sleeve with one end resting on the piston, - fixing the bottom on the sleeve, - placing the ring in the body, - the solidarity of the body and the background, - placing the head around the tube. Brief description of the drawings

[0022] The present application will be better understood with the aid of the description which follows and the attached drawings in which: [Fig.l] is a side view of an exemplary embodiment of a retractable crown mechanism according to the invention, the crown being in the raised position, [Fig.2] is a longitudinal sectional view of the mechanism of [Fig.l], [Fig.3] is an exploded view of the mechanism of [Fig.l], [Fig.4] is a partially broken away view of the mechanism of [Fig.l] showing the cooperation between a pin and the cam track, [Fig.5] is a partially cutaway 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 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 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, the crown being 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, the crown being in the pulled-out stem position, [Fig.10] is a bottom view of the retractable crown mechanism of [Fig.l], [Fig.l 1] is a front view of a timepiece comprising a retractable crown mechanism according to the invention. DETAILED DESCRIPTION OF EMBODIMENTS

[0023] In the following description, a proximal element designates an element located or oriented towards the watch case and a distal element designates an element located far away or oriented away from the watch case.

[0024] In Figures 1 to 11, one can see an example of an embodiment of a retractable or telescopic crown C for a timepiece, for example a wristwatch 2. In [Fig.l 1], one can see 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 clockwork mechanism (not visible) located in the watch case. For example, the crown is received in a housing made in a side face of the watch case.

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

[0026] The function of the crown is to allow action on the clockwork mechanism by manipulating the crown when the crown is in a certain axial position, hereinafter referred to as the extended position, for example to set the hours and minutes and / or wind the barrel spring of the clockwork mechanism.

[0027] The crown C extends along the longitudinal axis Y which is orthogonal to the axis X of the timepiece. The crown comprises a piston 12 intended to be fixed to the winding stem (not shown) of the timepiece mechanism by a proximal end 12.1. In this example, the proximal end 12.1 comprises an axial hole for fixing to the winding stem. The crown also comprises a tube 14 intended to be fixed to the watch case 4 at the right angle to the passage of the winding stem. The tube 14 is fixed to the watch case, for example by gluing or screwing. The crown comprises a head 16 which allows the manipulation of the crown C. In the example shown, the head 16 comprises on its lateral face grooves 17 facilitating the 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 back is made in several parts, for example if you want to add a part bearing a particular symbol.

[0029] The body 16.1 has a generally cylindrical shape of revolution bearing on its external lateral face grooves 17, closed at its distal end by the bottom 16.2 and comprising 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 axis Y. 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 side wall of the piston 12 are configured to allow rotational attachment to one another, 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, and 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 interlocking when the head is moved away from the watch case. The clutch system comprises, for example, polygonal shapes carried by the sleeve and the piston and which cooperate with each other when the head is moved away from the watch case. When the head is close to the watch case, the polygonal shapes are at a distance from each other, the sleeve and the piston are then not rotationally interlocked. Any other means allowing rotational interlocking of 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 bearing between the head and the piston 12.

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

[0034] The crown C also comprises 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 two and the pins 22 are arranged at 90° to each other. The pins 22 form the cam follower. The implementation of four pins 22 distributed angularly in a regular manner ensures balanced guidance of the head 16, however the number and arrangement of the pins are not limiting. It is then possible to envisage that the system comprises 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 comprises a cam path 24 or cam profile which is integral in movement with the head 16.

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

[0038] The crown C comprises a ring 26 mounted around the tube 14 and carrying the cam path 24. The ring 26 is mounted free to rotate around 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 loose ring. It is mounted with play in rotation and in translation around the tube and in the head.

[0039] The cam path is partly visible in Figures 4 and 5.

[0040] The cam path 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 low position PB or retracted position, in which the head 16 is in the first axial position, a high position PH or extended position, in which the head 16 is in the second axial position and intermediate positions PII, PI2 allowing the 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 path 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] The pins 22 being carried by the tube 14, which is intended to be fixed on the watch case, it is the cam track and therefore the ring 26 which 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 “actuation direction”. In the example shown, the actuation direction is clockwise. The cam track as well as the ring can only rotate in the actuation direction.

[0045] The positions are delimited by two longitudinal edge portions 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 comprises ramps connecting the positions, the ramps are formed by portions of the proximal 24.1 and distal 24.2 edges having an inclination relative to the Y axis.

[0048] In this example, the high position PH is delimited laterally 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 crown along the Y axis.

[0049] The low position PB is delimited laterally on the one hand by a portion 30.1 of proximal edge parallel to the Y axis and forming a stop in the direction of actuation, and on the other hand by a portion of ramp 30.2 of proximal edge inclined towards the proximal end in the direction of actuation. In addition, the intermediate position comprises a bottom 30.3 perpendicular to the Y axis.

[0050] The intermediate position PII is delimited in the 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 ramp portion 32.2 upstream, the ramp portion 32.2 being inclined towards the distal end. In this example, a bottom 32.3 perpendicular to the Y axis connects the portion 32.1 and the portion 32.2.

[0051] The configuration of the cam path to delimit the different positions PB, PH, PII, PI2 is in no way limiting. Indeed, it is possible to envisage that the low position does not have a bottom or that the intermediate position PII has a bottom.

[0052] The intermediate positions PII, PI2 are angularly offset relative to 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 an envelope 26.3 surrounding the parts 26.1 and 26.2 and securing the two parts 26.1, 26.2. This three-part construction allows simplified manufacturing of the ring 26. The elements are for example made by machining and turning, then welded for example by laser welding to each other. The first part comprises an annular surface 37 projecting radially outwards and intended to come into contact with 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 in the direction of the box to form a housing for the pins 22 whatever the axial position of the head.

[0055] Alternatively, the ring 26 is in one piece and is obtained by machining. Alternatively, the ring 26 is produced in one 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 24.1 and distal 24.2 edges are correctly arranged angularly and axially relative to each other. In the example shown, the proximal part 26.2 comprises a tubular part 36 of axis Y carrying the edge 24.1 of the cam path 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 made in the proximal longitudinal end of the casing 26.3; the distal part 26.1 comprises a tubular part of axis Y carrying at one end the edge 24.2 of the cam path 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 production. Alternatively, only one lug per proximal and distal part can be implemented. As a further variant, the lugs belong to the casing.

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

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

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

[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 subassembly 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 penetrate into the cam path. The pins 22 are angularly oriented so as to be arranged at right angles to a high position 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 high position PH, as can be seen in [Fig.4] and [Fig.8]. In this position, the crown C is in a spaced position relative to the watch case.

[0068] The user exerts an axial force on the head along the Y axis towards the watch case against the return 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 travel 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 bottom 32.3 comes into contact with the pin 22.

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

[0071] When the user wants to act on the watch mechanism, for example to charge the barrel spring or set the time, the user applies a force to the crown in the direction of the watch case against the return spring, the ramp R2 meets the pin 22 which, due to their cooperation, forces the ring to pivot clockwise ([Fig.7]). The user releases his force, it is then the ramp RI which 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 high position 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, acting on the clockwork mechanism to wind the barrel spring.

[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 exert a pulling force on the crown from its extended position to reach a stem-pulled position, to axially move the winding stem and allow other functions of the clockwork mechanism to be achieved, 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 manages the axial position of the crown and the rotational position of the crown is fixed by the user's manipulation.

[0075] The axial travel of the head for moving from one position to another can be adjusted according to the geometry of the cam path. For example, the travel is from 8 / 10 mm to 1 mm.

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

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

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

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

Claims

Claims

1. Crown intended to be placed on a watch case comprising a timepiece mechanism, said crown being intended to be connected to a winding stem of the timepiece mechanism, said crown of longitudinal axis (Y) comprising: - a tube (14) intended to be fixed on 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 attachment of the piston (12) and the sleeve (18), elastic means so as to separate the sleeve (18) and the piston (12),in which the tube (14) comprises at least one pin (22) projecting radially outwards and said head (16) comprises a cam path (24) configured to cooperate with the at least one pin (22), said cam path (24) defining at least one retracted position (PB) and one extended position (PH), and in which the cam path (24) is carried by a ring (26) mounted in rotation and in translation with play 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 section, a base (16.2) closing one end of the body and in which the ring (26) is mounted between the base (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 side of the bottom and the other axial part being opposite the bottom, each carrying an edge of the cam path (24) and in which the casing (26.3) secures the two axial parts (26.1, 26.2).

4. Crown according to claim 3, in which the edge of the cam path of the axial part opposite the bottom opens into an axial end opposite the bottom defining the extended position.

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

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

7. Crown according to one of claims 1 to 6, in which the tube comprises four pins (22), each cooperating with a portion of the cam path (24).

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

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

10. Method of assembling the crown according to one of claims 1 to 7, comprising: - inserting the piston into the sleeve, - placing the elastic means in the sleeve bearing by one end on the piston, - fixing the bottom on the sleeve, - placing the ring in the body, - securing the body and the bottom, - placing the head around the tube.

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