EP2224294B1 - Mechanism for setting the minute hand of a timepiece with automatic return-to-zero of the seconds hand - Google Patents

Description

The present invention relates to a timepiece with at least one minute hand and a second hand and a movement, which has a mechanism for setting the minute hand. This mechanism comprises a control shaft, which is adjustable by pulling or pressing a crown in the axial direction between a normal position and a parking position. The control shaft is coupled in its parking position in such a way with a minute gear group of the movement that a rotation of the actuating shaft causes an adjustment of the minute hand. In addition, the actuating shaft cooperates with a zeroing mechanism, which drives the second hand in its zero position upon movement of the actuating shaft in the parking position, blocking it in this zero position, while the actuating shaft is in the parking position, and him in a movement of the actuating shaft back in releases its normal position again.

Watches with such mechanisms are already known from the prior art. For example, the CH 18774/71 a watch provided with such a zeroing mechanism. If you pull the crown to set the time, the second hand will be set to zero and held in that position until the crown is pressed again.

A disadvantage of the known mechanisms is that the interaction between the second and minute hands is lost during the adjustment process. If the user rotates the crown and thus the actuating shaft with the crown pulled (adjusting shaft in the setting position), the minute tube on which the minute hand is seated is rotated via a corresponding gear train. The minute hand may be in an arbitrary position after the adjustment process, for example in the middle between two minute indices. If the movement runs after pressing When the crown comes up again, the second hand starts from zero while the minute hand starts from any position. Minute hand and second hand thus run asynchronously.

The patent document JP55-113976 publishes a detent mechanism with which the minute wheel group of the movement is provided, and allows 60 detent positions. Turning the control shaft in its position causes the minute tube and thus the minute hand to move step by step so that the minute hand can only be moved from one minute index to the next. So the minute hand never comes to lie between two minute indices. If you press the crown so that the movement starts again, the minute hand starts from a minute index, and the second hand from zero, and the two hands are in sync with it. However, this solution relates to a quartz watch, wherein no decoupling of the minute hand from the power flow of a barrel is needed.

The present invention has for its object to overcome this disadvantage.

This object is achieved on the basis of the preamble of claim 1 by the characterizing features of claim 1.

In order to decouple the adjustment of the minute hand from the power flow, the Kleinbodenradgruppe the clockwork is preferably carried out twice. In each case, one part lies in the power flow between the barrel and balance, while the other part is directly or indirectly coupled with the minute wheel in.

When the crown is pressed again, the zeroing drive and the balance are released again. The friction clutch ensures a play-free starting of the synchronized thanks to the inventive mechanism seconds and minute hands.

Advantageous embodiments of the invention are described in the subclaims and in the description which follows.

According to a particularly advantageous embodiment of the invention, the locking mechanism comprises a concentric with a minute wheel arranged and provided with 60 locking lugs on its inner circumference locking ring and at least one arranged within the locking ring, pivotally mounted latch. This latch is acted upon by a spring element radially outward and locked with the locking lugs of the locking ring. If the adjusting shaft is turned when the crown is pulled, then the locking ring is rotated in relation to the locking pawl. The latch is pressed by the shape of the latching lugs formed on the inside of the latching ring against the force of the spring element which pushes it outwards, in each case radially inward, and then locks again with the next latching lug. This gives a simple and reliable way to gradually adjust the minute hand.

Preferably, the latching mechanism comprises two symmetrically arranged latching pawls, which are each acted upon by an arm of the spring element radially outward. The spring element is otherwise preferably formed in two parts to facilitate its installation.

According to a particularly advantageous embodiment of the invention, the zeroing mechanism comprises a pivotable by an axial movement of the control shaft lever which pivots a reset lever on a movement of the actuating shaft in the position via an intermediate member, which in turn actuates a zeroing drive, which drives the second hand in its zero position.

The pivotable lever is preferably an angle lever and has a toothing. This toothing can interact with a corresponding toothing of the intermediate member.

Preferably, the intermediate member on a cam-like footprint and / or a toothing, which cooperates with the zeroing lever. The pivotal movement of the angle lever is then first transmitted to the intermediate member via the interlocking teeth, which performs a rotational movement. About the footprint and / or the second toothing of the intermediate member of the zeroing lever is pivoted

The zeroing lever then actuates the zeroing drive, which preferably comprises a heart-shaped control curve. Such heart-shaped control curves, also referred to as second-seconds, for zeroing the second hand are well known from the prior art.

According to a preferred embodiment of the invention, the zeroing lever is formed with two arms, wherein a first arm actuates the zeroing drive, and a second arm actuates a stopping mechanism for stopping a balance of the clock. In this case, the two-armed lever is preferably designed so that when the crown is pulled, the stop mechanism is already actuated shortly before the zero-setting drive. The zero position of the second hand is therefore only when the second hand is no longer moved by the movement.

According to a particularly advantageous embodiment of the invention, the zeroing lever has a spring-trained area. In the case of a two-armed zeroing lever, it is particularly advantageous if the first arm, i. the one arm which actuates the zeroing drive, is resilient. Due to the suspension, the force acting on the zeroing drive can be dosed appropriately, namely in such a way that a zero position is reliably achieved, but the secondary gear group is not damaged.

In order to decouple the adjustment of the minute hand from the power flow, the second wheel group of the movement is preferably also executed twice. In each case, one part lies in the power flow between the barrel and balance, while the other part is directly or indirectly coupled with the minute wheel in.

More precisely, for example, the second wheel group of the movement analogous to the low floor group comprise two superimposed and coupled via a friction clutch second wheels, with a first second wheel with the zero actuator and the Kleinbodenradgruppe with the minutes group is in communication, and a second second wheel in the power flow between the barrel and Balance is sitting. When the actuating shaft is in its normal position, the two low-floor wheels coupled via the friction clutch and the two second wheels each move together. When the control shaft is in its setting position, the zeroing drive rotates the first second wheel to zero the second hand. At the same time, the stop mechanism blocks the balance and thus the power flow. The two halves of the second wheel group and the low-wheel gear group, which are in operative connection with the zero-setting drive, now move in relation to their respective other halves located in the power flow.

When the crown is pressed again, the zeroing drive and the balance are released again. The friction clutches ensure a play-free starting of the seconds and minute hands synchronized thanks to the mechanism according to the invention.

Hereinafter, a preferred embodiment of the invention will be described with reference to the accompanying drawings.

• Fig. 1: eine perspektivische Ansicht eines Teils eines Uhrwerks einer Uhr, wobei eine Stellwelle sich in ihrer Normalposition befindet;
• Fig. 2A: eine seitliche Ansicht des gleichen Uhrwerkteils, wobei die Stellwelle sich in ihrer Normalposition befindet;
• Fig. 2B: eine Draufsicht des gleichen Uhrwerkteils, wobei die Stellwelle sich in ihrer Normalposition befindet;
• Fig. 3A: die gleiche Ansicht wie Fig. 2A, wobei die Stellwelle sich nun in ihrer Stellposition befindet;
• Fig. 3B: die gleiche Ansicht wie Fig. 2B, wobei die Stellwelle sich nun in ihrer Stellposition befindet;
• Fig. 4A: eine Draufsicht auf eine Minutenradgruppe des Uhrwerkteils aus den Fig. 1 bis 3;
• Fig. 4B: einen Schnitt entlang der Linie B-B in Fig. 4A;
• Fig. 4C: eine Explosionsdarstellung der Minutenradgruppe aus den Fig. 4A und 4B.

The figures show in detail:

• Fig. 1 a perspective view of a part of a clockwork of a clock, wherein a control shaft is in its normal position;
• Fig. 2A a side view of the same clockwork part, wherein the actuating shaft is in its normal position;
• Fig. 2B a plan view of the same movement part, wherein the control shaft is in its normal position;
• Fig. 3A : the same view as Fig. 2A , wherein the control shaft is now in its parking position;
• Fig. 3B : the same view as Fig. 2B , wherein the control shaft is now in its parking position;
• Fig. 4A : A plan view of a minute wheel group of the clockwork part from the Fig. 1 to 3 ;
• Fig. 4B : a section along the line BB in Fig. 4A ;
• Fig. 4C : An exploded view of the minute wheel group from the FIGS. 4A and 4B ,

The Fig. 1A shows a perspective view of a part of a clockwork of a clock according to the invention. The same clockwork part is in the Fig. 2A and 3A in top view and in the Fig. 2B and 3B shown in a side view. The adjusting shaft 16 is in FIGS. 2A and 2B as in Fig. 1 in their normal position while in FIGS. 3A and 3B axially displaced outwards into its parking position. When the control shaft 16, as in the Fig. 1 . 2A and 2B , in its normal position, the movement runs normally. The details of the function of the movement are well known to the skilled person and not the subject of the present invention, so that they will not be described here. For the meaning of the reference numerals not explained in detail below, reference is made to the list of reference numerals following the description of the figures.

As in particular in the lateral views of the Fig. 2A and 3A detects, a Kleinbodenradgruppe 34 of the movement comprises two superposed and over a plate spring 35 coupled to each other small ground wheels 34a, 34b. The upper Kleinbodenrad 34a communicates with a minutes wheel group 40 in connection, while the lower Kleinbodenrad 34b sits in the power flow between a barrel 10 and a balance wheel 26.

A second wheel group 32 of the movement is also made in two parts. Again, there is a lower part with a second wheel 32a in the power flow between the barrel 10 and the balance wheel 26. This lower second wheel 32 is also connected via a friction clutch, e.g. a plate spring or a spreading spring coupled to an upper second wheel 32b, which is rotatably connected to a zeroing heart 32c and a second axis 32d. The upper part of the second wheel group, i. the upper second wheel 32b, the nulling heart 32c and the second axle 32d are communicated with the minute wheel group 40 via the minor ground gear group 34.

When depressed crown an angle lever 18 holds with an 18a toothing an intermediate member 20 with an engaging in the toothing 18a of the angle lever 18 teeth 20a. The intermediate member 20 in turn holds on a second toothing 20b a zeroing lever 22. In this case, a toothing 22a of the zeroing lever 22 with the second toothing 20b of the intermediate member into engagement. The zeroing lever 22 is divided into a zeroing 22b and a stop arm 22c, whose function in consideration of the Fig. 3B will become clear. If the actuating shaft 16 is in its normal position, both arms 22b, 22c are each held in a neutral position.

When pulling the crown is, ie when adjusting the control shaft 16 in its parking position (see. FIGS. 3A and 3B The intermediate lever 20 pivots the zeroing lever 22 via the second toothing 20c and the footprint 20b. The zeroing arm 22b of the zeroing lever 22 is thereby counter to that of the second wheel group 32 corresponding Nullstellherz 32 c pressed, and the second axis 32 d with the second hand is moved to the zero position and fixed there.

At the same time, a stop arm 22c of the zeroing lever 22 shortly before reaching the effective range of the zeroing heart 32c

Brake lever 23 free, which in turn releases a brake spring 24, which then the balance 26 and thus the movement stops.

The zeroing arm 22b of the zeroing lever 22 is comparatively thin and thus resilient. The force with which the zeroing arm 22b acts on the zeroing core 32c is metered by this suspension, and the exact shape of the zeroing arm 22b and thus the spring force is selected so that the zero position of the second hand, not shown in the figures, works reliably, the second wheel group 32 but not damaged. Due to the specially arranged toothing 20b, 22a between the intermediate member 20 and the zeroing lever 22, the torque which builds up by the spring force of the zeroing arm 22b, not transmitted to the angle lever 18 on. The actuator shaft 16 and thus the crown can thus be easily rotated to set the time without the actuator automatically moves back to its normal position.

When turning the control shaft 16, the minute hand, not shown, is rotated over a minute tube 43. The rotation of the control shaft 16 is transmitted in a known manner via a corresponding gear train (inter alia change wheel 36) to the minute tube 43. By in the Figs. 4A, 4B and 4C more precisely detectable locking mechanism of the minute wheel group 40, this movement is gradual from one minute index to the next. How to get into the Figs. 4A, 4B and 4C sees, a locking ring 44 is provided, which is concentric with the minute wheel 42, wherein the outer diameter of the locking ring 44 is slightly smaller than that of the externally toothed minute wheel 42. The locking ring is rotatably connected to the minute tube 43 (see FIG. Fig. 4B ) and is provided on its inner circumference with 60 locking lugs 45. These locking lugs 45 define in cooperation with two latches 46 the 60 possible positions of the minute tube 43 and thus the minute hand. The two detents 46 are each pivotally mounted on a journal 47 on the minute wheel 42. A to simplify the Mounting two-piece expanding spring 48, which sits centrally on the minutes wheel 42, pushes the bearing pin 47 opposite end of the two locking blades 46 to the outside, so that the two locking blades 46 each come into contact with a contact surface 46a on a locking lug 45 of the locking ring 44 ,

If the adjusting shaft 16 is turned when the crown is pulled, then the minute tube 43 is rotated with the locking ring 44 via the change gear 36 and the gear train connecting it with the control shaft 16 with respect to the minute wheel 42 with its latching pawls 46. Since the zeroing heart 32c is blocked, the minute wheel 42 is thereby blocked by the small-wheel group 34 (cf. FIGS. 3A and 3B ). The latches 46 are thereby pressed by the locking lugs 45 against the force of the outwardly urging spring element 48 radially inward, and slide with the contact surfaces 46 a along the respective latch 45, so that the minute tube is rotated by 1/60 before they Latch 46 latch again with the next latch 45. The minute hand can thus be adjusted only gradually from one minute index to the next.

Pressing the crown and thus the control shaft 16 back to its normal position (see. Fig. 1 . 2A and 2B By engaging the teeth 20b, 22a between the intermediate member 20 and the reset lever 22, the reset lever 22 is again guided back to its neutral starting position. The zeroing arm 22b of the zeroing lever 22 releases the zeroing heart 32c on the second wheel group 32 again. At the same time, the brake lever 23 is also returned to its neutral position by the stop arm 22c of the zeroing lever 22, and the brake spring 24 is deflected away from the balance wheel 26 so that the balance wheel 26 is released again and the movement starts again.

The friction clutches, which couple the two low-order wheels 34a, 34b and the lower (32a) with the upper part (32b, 32c, 32d) of the second wheel group, ensure a backlash-free Start of the minute and second display. Thanks to the zeroing mechanism, the second hand starts from zero, while the minute hand starts from a minute index thanks to the locking mechanism. The two hands are thus synchronized.

LIST OF REFERENCE NUMBERS

10

barrel

12

Clutch lever spring

14

clutch lever

16

actuating shaft

18

bell crank

18a

gearing

20

intermediary

20a

gearing

20b

gearing

20c

footprint

22

Reset lever

22a

gearing

22b

Nullstellarm

22c

stopping arm

23

brake lever

24

brake spring

26

balance

28

anchor

30

escape wheel

32

Sekundenradgruppe

32a

lower second wheel

32b

upper second wheel

32c

Zeroing heart

32d

second axis

34

Kleinbodenradgruppe

34a

Third wheel

34b

Third wheel

35

Belleville spring

36

change gear

40

Minutenradgruppe

42

minute wheel

43

cannon

44

locking ring

45

locking lug

46

latch

46a

contact surface

47

pivot

48

spring element

Claims (12)

1. Timepiece comprising at least a minutes hand and a seconds hand, as well as movement comprising a mechanism for the setting of the minutes hand, wherein this mechanism comprises a setting stem (16), that can be moved axially between a normal position and a setting position, wherein said setting stem (16) is, in its setting position, coupled with a minute wheel group (40) of said movement, so that rotating the setting stem (16) actuates the setting of the minutes hand, and wherein said setting stem (16) further interacts with a zero-reset mechanism (18, 20, 22), which actuates the reset to zero of the seconds hand when the setting stem (16) is moved in its setting position, blocks it in this position as long as the setting stems (16) finds itself in such a position, and releases it again when the setting stem (16) is moved back to its normal position,
   wherein the minute wheel group (40) of the movement is fitted with a click mechanism (44, 45, 46), having 60 indexing positions, so that the minutes hand can be set in 60 different positions, each facing respectively a minute index when rotating setting stem (16) in its setting position,
   characterized in that
   a mean wheel group (34) of the movement comprises two wheels (34a,34b) arranged one above the other, and that are coupled to each other by friction (35), wherein a first mean wheel (34a) is connected to the minute wheel group (40), and a second mean wheel (34b) that lies within the transmission between a barrel (10) and a balance wheel (26).
2. Timepiece according to claim 1, characterized in that said click mechanism comprises a notch ring (44) arranged concentrically with respect to the minute wheel, that is fitted with 60 notches (45) on its inner circumference, and at least a pivoting pawl (46) arranged inside the notch ring (44), wherein the latter is urged radially towards the outside by an elastic member (48) to catch the notches (45) of the notch ring (44).
3. Timepiece according to claim 1, characterized in that said click mechanism comprises two pawls (46) arranged symmetrically, each being respectively urged radially towards the outside by an arm of the elastic member (48).
4. Timepiece according to one of the preceding claims, characterized in that the zero-reset mechanism comprises a pivoting lever (18) that can be pivoted when the setting stem is moved axially, and that actuates, when the setting stem (16) is moved to its setting position, the pivoting of a zero-reset lever (22) through an intermediary piece (20), whereby said zero-reset lever (22) drives a zero-reset control (32c) resetting the second hand to zero.
5. Timepiece according to claim 1, characterized in that the pivoting (18) lever is an angle lever that is fitted with a toothing (18a).
6. Timepiece according to claim 4 or 5, characterized in that said intermediary piece (20) is fitted with a toothing (20a) that cooperates with the toothing (18a) of the pivoting lever.
7. Timepiece according to any of claim 4 to 6, characterized in that said intermediary piece (20) is fitted with a setting surface (20c) and/or a toothing (20b) cooperating with the zero-reset lever (22).
8. Timepiece according to any of claim 4 to 7, characterized in that the zero-reset control (32c) comprises a heart-shaped cam.
9. Timepiece according to any of claim 4 to 8, characterized in that the zero-reset lever (22) is formed of two arms, wherein a first arm (22b) actuates the zero-reset control (32c), and a second arm (22c) actuates a stop mechanism (23, 24) stopping the balance wheel (26).
10. Timepiece according to any of claim 4 to 9, characterized in that the zero-reset lever (22) comprises an elastic portion.
11. Timepiece according to claim 9, characterized in that the first arm (22b) of the zero-reset lever (22) is elastic.
12. Timepiece according to any of the preceding claims, characterized in that a seconds wheel group (32) of the movement comprises two seconds wheels (32a,32b) coupled one to another, wherein a first seconds wheel (32a) is connected to the zero reset control (32c) and to the minute wheel group (40) through a mean wheel group (34), and a second seconds wheel (34b) that lies within the transmission between the barrel (10) and the balance wheel (26).

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