Patent Application
20180217556
The present invention concerns an assembly for holding or supporting a timepiece balance spring including a balance spring stud and a stud-holder.
In a mechanical watch, it is usual to use a regulating member comprising a sprung-balance device. Conventionally, the inner end of the balance spring is attached to a collet provided on the balance staff. In order to attach and position the inner end of the balance spring, it is known to use a stud-holder housing a balance spring stud, in association with a clamping screw to clamp the stud against the portion of the balance spring engaged in the stud-holder.
In such an assembly, the stud-holder is conventionally attached to a balance-cock also used for attaching one of the ends of the balance staff. The balance-cock is devised to incorporate a setting equipped with a shock-absorber device for the balance staff. A known stud-holder uses two rings. These two rings are mounted to be movable in rotation at the setting. Each ring comprises an extension in the shape of a tuning fork or a Y, the Y-shaped fork thus forming a housing.
A first ring is then used for housing the stud whereas the second ring is used for housing an adjustment element. This adjustment element makes it possible to adjust the limitation of the balance spring to adjust the rate and therefore the frequency of the balance spring.
Although such a device has proved effective for the steel balance springs currently used, it is considerably less practical for the use of the latest generation of silicon springs. Indeed, these materials have the reputation of being quite fragile. However, the current stud-holder requires a great deal of handling during assembly and after-sales service so that the risk of damaging silicon balance springs is considerable.
It is an object of the invention to overcome the drawbacks of the background art by proposing to provide an assembly for holding or supporting a timepiece balance spring which allows simplified assembly or disassembly of the balance spring stud.
To this end, the present invention concerns an assembly for holding or supporting a timepiece balance spring, comprising a balance spring stud and a stud-holder, characterized in that said stud-holder comprises a base having at least one circular portion, said base comprising, on said circular portion, a first plot and a second plot each extending radially; one of the two lugs comprising an elastic arm extending from the lug, in a direction parallel to that of the base, towards the other lug, said elastic arm forming with said base a housing for housing the balance spring stud and in that said first and second lugs are able to cooperate with a tool to allow the balance spring stud to exert a stress on the elastic arm to deform the latter and permit the assembly or disassembly of said stud.
This holding assembly according to the invention thus allows for simple assembly/disassembly of the balance spring stud which minimises stresses on the balance spring.
In a first advantageous embodiment, said stud-holder further comprises a notch arranged such that the balance spring stud can be housed therein.
In a second advantageous embodiment, the notch is arranged on the base.
In a third advantageous embodiment, the notch is arranged on the elastic arm.
In a fourth advantageous embodiment, the first lug and the second lug are angularly separated by an angle of less than 180 degrees.
The invention further concerns a method for assembly of a balance spring stud on a stud-holder, said stud-holder comprising a base having at least one circular portion attached to a balance-cock, said base comprising, on said circular portion, a first lug and a second lug each extending radially; the first lug comprising an elastic arm extending from its end, in a direction parallel to that of the base, towards the second lug, said elastic arm forming with said base a housing for housing the balance spring stud, said method comprising the following steps:
In a variant, the assembly method includes the following steps:
In a first advantageous embodiment, said stud-holder further comprises a notch arranged such that the balance spring stud can be housed therein.
The invention also concerns a method for disassembly of a balance spring stud from a stud-holder, said stud-holder comprising a base having at least one circular portion attached to a balance-cock, said base comprising, on said circular portion, a first lug and a second lug each extending radially; one of the two lugs comprising an elastic arm extending from the lug, in a direction parallel to that of the base, towards the other lug, said elastic arm forming with said base a housing for housing the balance spring stud, said method comprising the following steps:
In a variant, the method includes the following steps:
In a first advantageous embodiment, said stud-holder also includes a notch arranged such that the balance spring stud can be housed therein, the force exerted by the arms of said tool and transmitted to the elastic arm via the stud is sufficient to remove the stud from the notch.
The objects, advantages and features of the invention will appear more clearly in the following detailed description of at least one embodiment of the invention, given solely by way of non-limiting example and illustrated by the annexed drawings, in which:
The present invention proceeds from the general idea of providing an assembly for holding or supporting a timepiece balance spring permitting simpler assembly/disassembly of the balance spring stud.
Stud-holder 3 according to the invention comprises a base 30. This base 30 takes the form of an open ring or at least a part having at least one circular portion. This base 30 is attached to balance cock 2. A first possibility consists in giving a structure to balance-cock 2, for example by hollowing it out partly to form a chimney 20 on which the bearing body is mounted. This chimney is the element of the balance-cock that will be used for attaching base 30. Consequently, the chimney is structured to have a circular shape as seen in
Base 30 comprises means of attachment 31 for the attachment of balance spring stud 5. These attachment means 31 ingeniously comprise a first lug 32, this first lug 32 extends radially from base 30. The end of the lug is completed by an arm 33. Arm 33 is integral with lug 32 and extends, from the end of said lug 31, parallel to the curvature of base 30. Arm 33 is preferably elastic and is used for attaching the balance spring stud.
Elastic arm 33 and base 30 thus form a housing 34 into which balance spring stud 5 can be inserted.
Ingeniously according to the invention, it is provided that the assembly of the balance spring stud is simplified. To this end, base 30 is provided with a second lug 35. Second lug 35 also extends radially from said base. Second lug 35 is arranged such that the first lug and the second lug are angularly separated by an angle of less than 180°. The angle between the lugs is determined by the length required for the arm and the space available with the balance-cock. Preferably, the angle will be less than 120°. This arrangement allows a simple stud assembly method to be used. To this end, the stud is initially mounted on the balance spring.
In a first step, the balance spring is assembled to the stud, the stud is placed at the entrance to housing 34 formed by elastic arm 33 and base 30.
In a second step, the user takes a first tool or instrument of the tweezer type. This means an instrument such as fine pincers that can be provided with a spring. Once equipped with the tweezers, the user positions one of the tweezer arms resting on the balance spring stud and the second arm resting on first lug 32. More particularly, the tweezer arms are positioned such that they are apart and such that first lug 32 and balance spring stud 5 form an obstacle preventing the arms from returning to their rest position.
In a third step seen in
Once the stud is in the desired position, the user removes the tweezers. He can then perform an optional angular adjustment operation. Indeed, with a base 30 having a ring shape and mounted on the setting, base 30 could be arranged to be angularly movable. This advantageously allows the angular position of stud 5 to be modified to adjust the rate of the watch. To achieve this, the user uses tweezers. He can advantageously place the tweezer arms A on either side of second lug 35 pinching it with a pressure P″ or between first lug 32 and second lug 35. He can then move the ring clockwise or anticlockwise in order to modify the angular position of stud 5, as seen in
These assembly and adjustment operations are advantageous since they minimise handling operations and therefore minimise the stresses applied to the balance spring. In this manner, it is possible to envisage having a balance spring made of silicon type material, deemed to be less brittle than the conventional metal balance springs.
To disengage balance spring stud 5 from stud holder 3, several procedures are possible.
A first procedure consists in using tweezers, these tweezers being one of the basic tools of a watchmaker. Once the user is equipped with the tweezers, the procedure can start.
This first procedure uses the same principle as for the engagement of stud 5 on stud holder 3. Therefore, the user moves the tweezer arms apart so that one of the arms rests on second lug 35 while the other arm rests on stud 5, as seen in
Once the tweezers are in the right position, the user exerts a pressure P′ on said tweezer arms to attempt to return them to their initial position. The pressure exerted by the user is transmitted to stud 5 which, with second lug 35, is the only element adapted to be movable. Consequently, stud 5 it exerts a pressure on base 30 and on elastic arm 33. If the pressure exerted by the user increases, it may become sufficient to move aside elastic arm 33. In such case, stud 5 leaves notch 36. The user can then grasp said stud 5 with the tweezers and remove it from the housing as seen in
According to a second method for disengaging the stud seen in
In a variant of the invention, stud 5 may be made to have a conical shape, which allows it to be vertically engaged in the stud holder in the case of automated assembly.
It will be clear that various alterations and/or improvements and/or combinations evident to those skilled in the art may be made to the various embodiments of the invention set out above without departing from the scope of the invention defined by the annexed claims.
Thus, it will be understood that utilisation of screwdriver T may also be employed for assembly of the stud. The screwdriver head is inserted into the housing, preferably with the flat head extending parallel to the base. The user then rotates the screwdriver on itself. This rotation allows the screwdriver to enter into contact with the base and the elastic arm. If the user continues to rotate the screwdriver, leverage occurs, as the dimensions of the screwdriver are defined to make this possible. The leverage then causes a force to occur on elastic arm 33 and base 30. Given that elastic arm 33 is the only element able to be deformed, the leverage causes deformation of said arm. This deformation results in the enlargement of housing 34 and the possibility of slipping the stud into the housing.
| Number | Date | Country | Kind |
|---|---|---|---|
| 15199633. 7 | Dec 2015 | EP | regional |
This application is a divisional of U.S. patent application Ser. No. 15/339,322, filed Oct. 31, 2016, and claims the benefit of priority under 35 U.S.C. § 119 to European Patent Application No. 15199633.7, filed on Dec. 11, 2015. The entire contents of each of the above applications are incorporated herein by reference in entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15339322 | Oct 2016 | US |
| Child | 15936116 | US |
