Zero-reset device for a timepiece

Abstract

The invention relates to a zero-reset device (1) for a timepiece, which device comprises a control member (2), at least two zero-reset cams (40, 42, 44), at least two hammers (34, 36, 38) which can pivot independently of one another and are arranged to cooperate respectively with the zero-reset cams (40, 42, 44), at least two hammer springs (28, 30, 32) which are arranged respectively to exert forces on the hammers (34, 36, 38), which forces work to pivot the hammers (34, 36, 38) towards the zero-reset cams (40, 42, 44), locking means (52) for locking the hammers (34, 36, 38) against the action of the hammer springs (28, 30, 32) during a first phase of actuation of the control member (2), and winding and release means (16, 18, 20) for winding the hammer springs (28, 30, 32) during the first phase of actuation of the control member (2) and for moving the locking means (52) so that the locking means (52) release the hammers (34, 36, 38) during a second phase of actuation of the control member (2) so that the hammers (34, 36, 38) strike the zero-reset cams (40, 42, 44). In order to lock the hammers (34, 36, 38) during the first phase, the locking means (52) comprise at least two locking elements (64, 66, 68) which are arranged so as to respectively cooperate with the hammers (34, 36, 38). The winding and release means comprise at least two winding levers (16, 18, 20) which are arranged to be controlled in parallel by the control member (2) and to respectively wind the hammer springs (28, 30, 32) during the first phase.

Description

[0001] Reset device for timepiece

[0002] The present invention relates to a zero-resetting device for a timepiece, in particular for a chronograph.

[0003] Patent EP 2884350 discloses a zero-reset device comprising a first control means (push button), a second control means kinematically linked to the first control means, at least two zero-reset cams, at least two zero-reset hammers pivoted independently of each other and arranged to cooperate respectively with the zero-reset cams and at least two hammer springs tending respectively to pivot the zero-reset hammers towards the zero-reset cams. This zero-reset device further comprises a winding and triggering means constituted by a bar kinematically linked to the second control means and carrying winding pins, as well as a locking means constituted by a lever.

[0004] In the rest position of this reset device, a free end of the second control means presses on a first of the hammers to keep it away from the corresponding reset cam. The hammers are connected in series by a return bar (with a certain clearance) or, alternatively, by additional arms which the hammers respectively comprise, so that the pressure of the second control means on the first hammer also has the effect of keeping the other hammer(s) away from their cams. During a first phase of an actuation of the first control means, the winding and triggering means winds the hammer springs via its winding pins. The second control means then no longer acts on the first hammer but the latter is prevented from moving towards the corresponding cam by the locking means which is in its rest position.During a second phase of the actuation of the first control means, the arming and triggering means cooperate with the locking means to move the latter from its rest position to a trigger position in which it releases the first hammer, and therefore also the other hammer(s). Under the action of the hammer springs, the hammers then fall on the cams to carry out the reset. As soon as the first control means is released by the user, the free end of the second control means returns to act on the first hammer to return it to its rest position away from the corresponding cam. During this movement, the return bar or the additional arms of the hammers return the other hammer(s) to their rest position.

[0005] This reset device has several advantages over conventional reset devices, including the fact that the force applied to the hammers to strike the cams is well defined and that the hammers are independent, so can each actuate their cam precisely.

[0006] The independence of the hammers in this zero-reset device is, however, relative, because of the return bar or additional arms that connect them in series. Such a series connection considerably limits the possibilities of arranging the device and adapting it to the space constraints imposed by the watch mechanism in which the device is intended to be integrated.

[0007] The present invention aims to provide greater flexibility in the arrangement of the reset device and the use of the available volume.

[0008] To this end, a reset device for a timepiece is proposed comprising a control member, typically actuable (directly or indirectly) by a user, at least two reset cams, at least two hammers pivotable independently of each other and arranged to cooperate respectively with the reset cams, at least two hammer springs arranged to exert on the hammers respectively forces tending to pivot the hammers towards the reset cams, locking means for blocking the hammers against the action of the hammer springs during a first phase of an actuation of the control member,and arming and triggering means for arming the hammer springs during the first phase of actuation of the control member and for moving the locking means so that the locking means release the hammers during a second phase of actuation of the control member so that the hammers strike the reset cams, characterized in that, for locking the hammers during said first phase, the locking means comprise at least two locking elements arranged to cooperate respectively with the hammers, and in that the arming and triggering means comprise at least two arming levers arranged to be controlled in parallel by the control member and to arm the hammer springs respectively during said first phase.,

[0009] Preferably, the reset device according to the invention further comprises at least one of the following characteristics:

[0010] - each cocking lever is arranged to return the corresponding hammer to a rest position distant from the corresponding reset cam when the control member returns to its initial position after its actuation;

[0011] - each cocking lever is pivotally mounted around the same axis as the corresponding hammer;

[0012] - each cocking lever is coplanar with the corresponding hammer and guided in rotation by a head of the corresponding hammer;

[0013] - each cocking lever forms a single piece with the corresponding hammer spring;

[0014] - the locking means are arranged to be moved by at least one of the arming levers to release the hammers during said second phase; - the hammers comprise first and second coplanar hammers located on either side of the locking means;

[0015] - the hammers comprise a third hammer not coplanar with the first and second hammers;

[0016] - the arming and triggering means further comprise an intermediate member arranged to be controlled by the control member, to control the arming levers in parallel and to move the locking means so as to release the hammers during said second phase so that the latter strike the reset cams;

[0017] - the intermediate member is movable in translation;

[0018] - the locking means comprise at least two locking levers respectively comprising the blocking elements and pivoting independently of each other;

[0019] - a member, preferably all-or-nothing, is arranged to act on the control member so as to prevent the control member from returning to its initial position after its actuation in order to keep the hammers pressing against the reset cams.

[0020] The present invention further provides a timepiece, for example a watch, in particular a chronograph watch, comprising a zero-resetting device as defined above.

[0021] Other characteristics and advantages of the present invention will appear on reading the following detailed description given with reference to the appended drawings in which: Figure 1 is a perspective view of a zero-reset device according to a first embodiment of the invention after its actuation; - Figure 2 is a plan view from above of the zero-reset device according to the first embodiment of the invention in a rest state;

[0022] - Figure 3 is a plan view from above of the reset device according to the first embodiment of the invention in a state armed by the user during a reset;

[0023] - figure 4 is a plan view from above of the reset device according to the first embodiment of the invention after its actuation;

[0024] - figure 5 is a plan view from above of a reset device according to a second embodiment of the invention during its arming by the user during a reset;

[0025] - figure 6 is the same view as figure 5 but makes the hidden parts visible by transparency.

[0026] With reference to Figures 1 and 2, a zero-reset device 1 according to a first embodiment of the invention, for a timepiece mechanism such as a chronograph or split-seconds mechanism, comprises a control lever 2 pivoted at a point 4 and subjected to the action of a return spring 6 which tends to keep it in a rest position resting against a stop 8. A first end 10 of the control lever 2 is articulated to a push button 12 (represented schematically by an arrow) which allows the user to actuate the control lever 2 against the action of the return spring 6. At a second end 14 of the control lever 2 are articulated three winding levers 16, 18, 20, for example by means of an opening 22 which this end 14 has and in which pins carried by the winding levers 16, 18, 20 are engaged.In the example shown, two arming levers 16, 18 among the three arming levers are coplanar, the third arming lever 20 is located in another plane while being coaxial with one, 16, of the two coplanar arming levers 16, 18, a first pin 24 carried by the arming lever 16 passes through the arming lever 20 to engage in the opening 22 and articulate the arming levers 16, 20 to the control lever 2, and a second pin 26 carried by the arming lever 18 engages in the opening 22 to articulate the arming lever 18 to the control lever 2.

[0027] From each winding lever 16, 18, 20 extends in a single piece with the winding lever a blade forming a hammer spring 28, 30, 32. By their free end, the three hammer springs 28, 30, 32 bear respectively on three hammers 34, 36, 38 and tend to move these three hammers towards three respective reset cams 40, 42, 44. The imaginary axes of rotation 46, 48, 50 of the hammers 34, 36, 38, like those of the arming levers 16, 18, 20, of the control lever 2, of the reset cams 40, 42, 44 and of the locking means 52 which will be described, are fixed relative to the frame on which the reset device 1 is mounted, and the hammers 34, 36, 38 are mounted to pivot independently of each other.Preferably, as illustrated, each hammer 34, 36, 38 is coaxial and coplanar with the corresponding winding lever 16, 18, 20 and comprises a head (only the heads 54, 56 of the hammers 34, 36 are visible in the drawings) which guides the winding lever in rotation around their common axis 46, 48, 50. The reset cams 40, 42, 44 are typically heart-shaped, as is known per se. The reset cams 40, 42, 44 are for example secured respectively to a minute counter hand, an hour counter hand and a chronograph second hand.

[0028] Locking means 52 are placed in the center of the device 1. These locking means 52 comprise three blocking elements 64, 66, 68 arranged to cooperate with three corresponding blocking elements 70, 72, 74 of the three hammers 34, 36, 38 respectively, as well as at least one triggering element 76, 77 arranged to cooperate with at least one corresponding triggering element 78, 79 of the set of three arming levers 16,

[0029] 18, 20.In the example shown, the locking means 52 are in the form of two independent, rotating, coaxial locking members 53a, 53b, each subjected to the action of a return spring 62a, 62b, the blocking elements 64, 66 and a first triggering element 76 are protrusions of the locking member 53a which is coplanar with the winding levers 16, 18 and the hammers 34, 36, the blocking element 68 is a protrusion of the locking member 53b which is coplanar with the winding lever 20 and the hammer 38, the winding lever 16 comprises a second triggering element 78, in the form of a protrusion, arranged to cooperate with the first triggering element 76, and the locking member 53b comprises a third triggering element 77, in the form of a recess, arranged to cooperate with a fourth trigger element 79, in the form of a protrusion, which the arming lever 20 comprises.In variants, however, the two locking members 53a, 53b could be integral and together have only one triggering element associated with a single triggering element of the set of cocking levers 16, 18, 20, or an independent locking member having a blocking element and a triggering element associated with a triggering element of a respective cocking lever could be provided for each of the hammers 34, 36, 38.

[0030] The device 1 operates in the following manner. In its rest state (Figure 2), the control lever 2 is held against its stop 8 by the return spring 6, the locking means 52 are held by their return springs 62a, 62b in a locking position against a common stop 63 where their blocking elements 64, 66, 68 are in the path of the blocking elements 70, 72, 74 of the hammers and therefore prevent the hammers from falling towards the reset cams, and the hammer springs 28, 30, 32 are slightly armed. When the user actuates the push button 12 (figure 3), the latter pivots the control lever 2 against the action of its return spring 6 (i.e. counterclockwise in the figures), which pivots each of the three cocking levers 16, 18, 20 in a direction which brings it closer to the angular position of the corresponding hammer 34, 36, 38.During a first phase of the actuation of the push button 12 and the control lever 2, the locking means 52 remain in their locking position so that, the hammers 34, 36, 38 being blocked by the locking means 52, the movement of the arming levers 16, 18, 20 arms the hammer springs 28, 30, 32.

[0031] At a given instant during the actuation of the push button 12 and the control lever 2, the triggering elements 78, 79 of the winding levers 16, 20 come into contact with the triggering elements 76, 77 of the locking means 52 (Figure 3 shows the state of the device 1 shortly after this instant). Then begins a second phase of said actuation, typically much shorter than the first phase, where the movement of the winding levers 16, 18, 20 by the control lever 2 causes the locking means 52 to pivot (clockwise in the figures) by the cooperation between the triggering elements 76, 78 and that between the triggering elements 77, 79.As soon as the locking elements 64, 66, 68 of the locking means 52 leave the path of the locking elements 70, 72, 74 of the hammers (figure 4), the hammers 34, 36, 38 are released and, under the action of the hammer springs 28, 30, 32, will strike the reset cams 40, 42, 44 to reposition them and reposition with them the indicator needles which they carry.

[0032] When the push button 12 is released, the return spring 6 returns the control lever 2 to its rest position and, by means of drive elements which they comprise (of which only two, 80, 82, are visible in the drawings), the winding levers 16, 18, 20 driven by the control lever 2 raise the hammers 34, 36, 38 to their initial, rest position, the return springs 62a, 62b then returning the locking means 52 to their locking position. The reset device 1 may further comprise an all-or-nothing member comprising, for example, as shown in the figures, a lever 86 pivoted at a point 88, terminated by a hook 90 and on which a return spring 92 acts. In the rest state of the device 1 (figure 2), the hook 90 rests on a surface 94 of the periphery of the control lever 2.When the control lever 2 is actuated (Figure 3), the hook 90 slides over the surface 94 and then passes a tooth 96, felt by the user as a hard point, just before the locking means 52 release the hammers 34, 36, 38, to position themselves on the other side of the tooth 96 (Figure 4) and prevent the control lever 2 from returning back. This ensures that minimal force must be exerted by the user to perform the reset. In addition, by preventing the control lever 2 from returning to its rest position after its actuation and after the release of the push button 12, the hammers 34, 36, 38 are allowed to remain in contact with the reset cams 40, 42, 44 and thus to maintain the corresponding indicator hands in position without resorting to brakes.A set of levers may be provided to, when restarting the chronograph function, act on the all-or-nothing organ 86, 92 so that it releases the control lever 2 and the latter raises the hammers 34, 36, 38 by means of the winding levers 16, 18, 20.

[0033] Thanks to the locking means 52 which cooperate with each of the hammers 34, 36, 38 and to the winding levers 16, 18, 20 controlled in parallel by the control lever 2, the zero-resetting device 1 according to the invention can take multiple forms, with for example coplanar or non-coplanar hammers, symmetrical or non-symmetrical, hammer strokes identical or different from each other, identical or different forces exerted on the hammers, identical or different shapes or sizes of zero-resetting cams, identical or different safety devices on the hammers, identical or different triggering times for resetting the different indicator hands, all to meet criteria of size, force distribution and / or aesthetics for example.The high independence of the hammers also facilitates maintenance, fault detection and repairs of the device since each sub-assembly of the cocking lever - hammer - cam can be tested separately.

[0034] Furthermore, it will be appreciated that the coaxial arrangement of each arming lever 16, 18, 20 and the corresponding hammer 34, 36, 38, the rotational guidance of each arming lever 16, 18, 20 by a head 54, 56 of the corresponding hammer 34, 36, 38, the production of each hammer spring 28, 30, 32 in a single piece with the corresponding arming lever 16, 18, 20 and the placement of the locking means 52 in the center of the device 1, are all characteristics which make it possible to optimize the size.

[0035] A zero-reset device T according to a second embodiment of the invention, for a timepiece mechanism such as a chronograph or split-seconds mechanism, is shown in Figures 5 and 6. Compared to the device 1 according to the first embodiment, this zero-reset device T comprises an additional control member, called intermediate member 100, interposed between the control lever 2' and the three winding levers 16', 18', 20'. This intermediate member 100 is typically in the form of a translationally guided part to which the end of the control lever 2' opposite that articulated to the push button 12' and the respective ends of the winding levers 16', 18', 20' are articulated. Thus, this intermediate member 100 is controlled by the control lever 2' and in turn controls, in parallel, the arming levers 16', 18', 20'.In the example shown, the arming levers 16', 18', 20' pivot around separate axes and two of them, 16' and 18', are coplanar while the third 20' is located in another plane. In the example shown, also, the locking means 52' are in the form of three independent locking levers 102, 104, 106 subjected to the action of respective return springs 108, 110, 112 which tend to keep them pressed against the intermediate member 100, more precisely against tabs 114, 116, 118 of the intermediate member 100. A surface of each locking lever 102, 104, 106 constitutes a blocking element 64', 66', 68' (see FIG. 6) located, in the rest state of the device T, on the path of a pin 120, 122, 124 which comprises the corresponding hammer 34', 36', 38' and thus preventing the corresponding hammer from moving towards the reset cam 40', 42', 44' corresponding.

[0036] In this second embodiment, it is the intermediate member 100, and not the winding levers 16', 18', 20', which moves the locking means 52' to trigger the reset. In the rest state of the device T, the control lever 2' is held against a stop (not shown) by its return spring 6', the locking levers 102, 104, 106 are held against the intermediate member 100 by their return springs 108, 110, 112 and prevent the hammers 34', 36', 38' from falling onto the reset cams 40', 42', 44', and the hammer springs 28', 30', 32' are slightly armed.When the user actuates the push button 12', the latter pivots the control lever 2' against the action of its return spring 6' (i.e. counterclockwise in Figures 5 and 6), which moves in translation (downwards in Figures 5 and 6) the intermediate member 100, pivots each of the three arming levers 16', 18', 20' in a direction which brings it closer to the angular position of the corresponding hammer 34', 36', 38', and pivots each of the three locking levers 102, 104, 106. During a first phase of the actuation of the push button 12' and the control lever 2', the locking levers 102, 104, 106, although moved by the intermediate member 100, remain at least partially on the path of the pins 120, 122, 124 so that, the hammers 34', 36', 38' being blocked by the locking levers 102, 104, 106, the movement of the cocking levers 16', 18', 20' cocks the hammer springs 28', 30', 32'.

[0037] During a second, typically very short, phase of the actuation of the push button 12' and the control lever 2', the locking levers 102, 104, 106 come out of the path of the pins 120, 122, 124, thus releasing the hammers 34', 36', 38' which, under the action of the hammer springs 28', 30', 32', will strike the reset cams 40', 42', 44' to reposition them and reposition with them the indicator needles which they carry.

[0038] When the push button 12' is released, the return spring 6' returns the control lever 2' to its rest position and, by means of drive elements 80', 82', 84' which they comprise, the arming levers 16', 18', 20' driven by the intermediate member 100 itself driven by the control lever 2' raise the hammers 34', 36', 38' to their initial, rest position, the return springs 108, 110, 112 then returning the locking levers 102, 104, 106 to their locking position.

[0039] The reset device T may comprise an all-or-nothing member similar to the member 86, 92 used in the first embodiment.

[0040] The reset device T has the same advantages as the device 1 illustrated in figures 1 to 4, with in addition increased independence of the arming levers and the locking means associated respectively with the hammers and with a distribution of forces which can be very different.

[0041] In the described embodiments, three cocking lever - hammer - cam sub-assemblies are provided. Their number could however be different, provided that it is at least equal to two.

[0042] Although the present invention finds a particular application in resetting the hands of a chronograph, it is not limited to such an application. The present invention can indeed be applied to any timepiece in which it is desired to be able to reset one or more hands.

Claims

CLAIMS 1. A zero-resetting device (1; T) for a timepiece comprising a control member (2; 2'), at least two zero-resetting cams (40, 42, 44; 40', 42', 44'), at least two hammers (34, 36, 38; 34', 36', 38') pivotable independently of each other and arranged to cooperate respectively with the zero-resetting cams (40, 42, 44; 40', 42', 44'), at least two hammer springs (28, 30, 32; 28', 30', 32') arranged to exert on the hammers (34, 36, 38; 34', 36', 38') respectively forces tending to pivot the hammers (34, 36, 38; 34', 36', 38') to the reset cams (40, 42, 44; 40', 42', 44'), locking means (52; 52') for blocking the hammers (34, 36, 38; 34', 36', 38') against the action of the hammer springs (28, 30, 32; 28', 30', 32') during a first phase of an actuation of the control member (2; 2'), and arming and triggering means (16, 18, 20;16', 18', 20', 100) for loading the hammer springs (28, 30, 32; 28', 30', 32') during the first phase of actuation of the control member (2; 2') and for moving the locking means (52; 52') so that the locking means (52; 52') release the hammers (34, 36, 38; 34', 36', 38') during a second phase of actuation of the control member (2; 2') so that the hammers (34, 36, 38; 34', 36', 38') strike the reset cams (40, 42, 44; 40', 42', 44'), characterized in that, for locking the hammers (34, 36, 38; 34', 36', 38') during said first phase, the locking means (52; 52') comprise at least two blocking elements (64, 66, 68; 64', 66', 68') arranged to cooperate respectively with the hammers (34, 36, 38; 34', 36', 38'), and in that the arming and triggering means comprise at least two arming levers (16, 18, 20; 16', 18', 20'); arranged to be controlled in parallel by the control member (2; 2') and to respectively arm the hammer springs (28, 30, 32; 28', 30', 32') during said first phase.

2. Device according to claim 1, characterized in that each arming lever (16, 18, 20; 16', 18', 20') is arranged to return the corresponding hammer (34, 36, 38; 34', 36', 38') to a rest position remote from the corresponding reset cam (40, 42, 44; 40', 42', 44') upon return of the control member (2; 2') to its initial position after its actuation.

3. Device according to claim 1 or 2, characterized in that each arming lever (16, 18, 20; 16', 18', 20') is pivotally mounted around the same axis (46, 48, 50) as the corresponding hammer (34, 36, 38; 34', 36', 38').

4. Device according to claim 3, characterized in that each arming lever (16, 18, 20; 16', 18', 20') is coplanar with the corresponding hammer (34, 36, 38; 34', 36', 38') and guided in rotation by a head (54, 56) of the corresponding hammer (34, 36, 38).

5. Device according to any one of claims 1 to 4, characterized in that each cocking lever (16, 18, 20; 16', 18', 20') forms a single piece with the corresponding hammer spring (28, 30, 32; 28', 30', 32').

6. Device according to any one of claims 1 to 5, characterized in that the locking means (52) are arranged to be moved by at least one (16) of the arming levers (16, 18, 20) to release the hammers (34, 36, 38) during said second phase.

7. Device according to any one of claims 1 to 6, characterized in that the hammers (34, 36, 38) comprise first and second hammers (34, 36) which are coplanar and located on either side of the locking means (52).

8. Device according to claim 7, characterized in that the hammers (34, 36, 38) comprise a third hammer (38) not coplanar with the first and second hammers (34, 36).

9. Device according to any one of claims 1 to 5, characterized in that the arming and triggering means (16', 18', 20', 100) further comprise an intermediate member (100) arranged to be controlled by the control member (2'), to control in parallel the arming levers (16', 18', 20') and to move the locking means (52') so as to release the hammers (34', 36', 38') during said second phase so that the latter strike the reset cams (40', 42', 44').

10. Device according to claim 9, characterized in that the intermediate member (100) is movable in translation.

11. Device according to claim 9 or 10, characterized in that the locking means (52') comprise at least two locking levers (102, 104, 106) respectively comprising the blocking elements (64', 66', 68') and pivotable independently of one another.

12. Device according to any one of claims 1 to 11, characterized in that it comprises a member (86, 92) arranged to act on the member of control (2; 2') so as to prevent the control member (2; 2') from returning to its initial position after its actuation in order to keep the hammers (34, 36, 38; 34', 36', 38') pressing against the reset cams (40, 42, 44; 40', 42', 44').

13. Device according to claim 12, characterized in that said member (86, 92) arranged to act on the control member is an all-or-nothing member.

14. Timepiece comprising a zero-resetting device according to any one of claims 1 to 13.

Images