EP2806314A1 - Shock absorber with bayonet - Google Patents

Abstract

The present invention relates to a shock absorbing device (100) for an axis of a component of a timepiece comprising a support (110) comprising a bottom cup (111) surmounted by a delimited peripheral rim (112), opposite said cup, by an upper surface (113), said cup and the flange together defining a housing (114), the device further comprising a pivot system (120) extending along an axis (D), said pivot system being arranged in said housing and formed of a base (121) having resilient return means (123) at its periphery formed by at least one curved arm (124), and having an opening (121a) in which a pivot member (122) adapted to cooperate with said axis is inserted. Said at least one curved arm is used for bayonet immobilization of the pivot system.

Description

The present invention relates to a shock absorbing device for an axis of a component of a timepiece comprising a hollow support comprising a bottom cup surmounted by a peripheral rim delimited, opposite said cup, by a surface upper, said cup and the flange together defining a housing, the device further comprising a pivot system extending along an axis, said pivot system being arranged in said housing and formed of a base having resilient return means at its periphery formed by at least one curved arm, and having an opening in which a pivot member adapted to cooperate with an axis is inserted.

BACKGROUND TECHNOLOGY

Shock absorbing devices for an axis of a component of a timepiece are known, such as a rocker arm or an axis carrying a gear wheel, comprising a support in which a housing is arranged. This housing has a pierced bottom through which the spindle of the axis passes and an inner wall. The device further comprises a pivot system 1, visible to the figure 1 , arranged in said housing and having a base 2 comprising elastic return means 3 at its periphery. These return means are in the form of arms 4 and are then connected by a first end to the base 2 and by a second end to a peripheral annular piece 5 as visible in FIG. figure 1 .

The base has an opening 6 in which a pivot element adapted to cooperate with an axis is inserted. This pivot element and the base can be one piece.

When mounting the shock absorbing device, the shock absorbing device is then driven into the housing of the support.

A disadvantage of these known shock absorber devices is that they are bulky. Indeed, these devices arm by nature have a larger surface than systems lyre. This space is further increased with the presence of the annular piece on which the second ends of the return means are fixed.

Consequently, this type of shock-absorbing device can only be used on large watch movements and not on watch movements with reduced dimensions.

Another disadvantage of these devices is the rigidity of the attachment between the elastic return means that is to say the arms and the peripheral annular piece. Indeed, with the principle of driving the device in the support housing, the rigidity of the attachment of the arms on the peripheral annular piece acts as if the arms were rigidly fixed to the support. This fixation then generates constraints in the arms. These must then be dimensioned accordingly in order to avoid any risk of breakage.

SUMMARY OF THE INVENTION

The object of the invention is to overcome the disadvantages of the prior art by proposing to provide a shock absorbing device that is both more compact and less stressed.

For this purpose, the present invention relates to a shock absorbing device for an axis of a component of a timepiece comprising a hollow support having a bottom cup surmounted by a delimited peripheral rim, opposite said cup. , by an upper surface, said cup and the rim together defining a housing, the device further comprising at least one pivoting system extending along an axis, said at least one pivot system being arranged in said housing and formed of a base comprising resilient return means at its periphery formed by at least one curved arm, and having an opening in which a pivot element adapted to cooperate with an axis is inserted, characterized in that the flange comprises in its thickness at least one cavity comprising a clearance parallel to said axis (D) and opening relative to the upper surface, and secant with said first clearance and the opposite of the upper surface, a blind groove used for the bayonet immobilization of a curved arm of said at least one pivot system.

The advantage of this device is that it is more compact and therefore can be used for watch movements of small sizes.

In addition, the bayonet attachment mode has the advantage of being simple and easier to dismantle than the hunting usually used.

In a first advantageous embodiment, said at least one arm has a free end, said free end engaging in said at least one groove.

In a second advantageous embodiment, the groove comprises a recess in which a lug located at the free end of said at least one curved arm fits.

In a third advantageous embodiment, the pivot element comprises a single stone.

In another advantageous embodiment, the pivot element comprises a kitten in which are immobilized a pierced stone traversed by the tigeron of the axis and a stone against pivot.

In another advantageous embodiment, the pivot element and the base are in one piece.

In another advantageous embodiment, the elastic return means are formed by three curved arms angularly offset by 120 °, said flange having, in its thickness, three cavities.

In another advantageous embodiment, the shock absorbing device further comprises an additional spring allowing, in the event of axial impact, to bring the axis back to its initial position.

In another advantageous embodiment, said additional spring is a lyre-type spring in the form of an open ring comprising a hinge and two locking lugs.

In another advantageous embodiment, said additional spring is an annular flat spring in the form of a closed ring having axially extending bearing surfaces.

In another advantageous embodiment, the device comprises two pivot systems using the same cavity for the bayonet immobilization of a curved arm of each pivot system.

In another advantageous embodiment, the device comprises two pivot systems each using a cavity for bayonet immobilization of a curved arm of said pivot system.

BRIEF DESCRIPTION OF THE FIGURES

• La figure 1 représente schématiquement un dispositif amortisseur de chocs selon l'art antérieur ;
• La figure 2 représente schématiquement un premier mode de réalisation d'un dispositif amortisseur de chocs selon l'invention ;
• La figure 3 représente schématiquement une vue en coupe du dispositif amortisseur de chocs selon l'invention ;
• La figure 4 représente schématiquement le support du dispositif amortisseur de chocs selon l'invention ;
• La figure 5 représente schématiquement une vue de dessous du système pivot du dispositif amortisseur de chocs selon un exemple de réalisation de l'invention ;
• Les figures 6 et 7 représentent schématiquement des exemples de réalisations d'un dispositif amortisseur de chocs selon l'invention;
• Les figures 8 et 9 représentent schématiquement un second mode de réalisation d'un dispositif amortisseur de chocs selon l'invention, et
• La figure 10 représente schématiquement un troisième mode de réalisation d'un dispositif amortisseur de chocs selon l'invention ;

The aims, advantages and characteristics of the shock absorbing device according to the present invention will appear more clearly in the following detailed description of at least one embodiment of the invention given solely by way of nonlimiting example and illustrated by the appended drawings. on which ones :

• The figure 1 schematically represents a shock absorbing device according to the prior art;
• The figure 2 schematically represents a first embodiment of a shock absorber device according to the invention;
• The figure 3 schematically represents a sectional view of the shock absorbing device according to the invention;
• The figure 4 schematically represents the support of the shock absorbing device according to the invention;
• The figure 5 schematically represents a bottom view of the pivot system of the shock absorber device according to an exemplary embodiment of the invention;
• The Figures 6 and 7 schematically show examples of embodiments of a shock absorber device according to the invention;
• The figures 8 and 9 schematically represent a second embodiment of a shock-absorbing device according to the invention, and
• The figure 10 schematically represents a third embodiment of a shock-absorbing device according to the invention;

DETAILED DESCRIPTION

On the figures 2 and 3 , a shock absorbing device 100 according to a first embodiment of the invention is shown. This shock absorbing device can be used for a part of a timepiece.

The shock absorbing device 100 or anti-shock device comprises a hollow support 110 comprising a bottom cup 111 surmounted by a delimited peripheral rim 112, opposite said cup, by an upper surface 113. The cup and the rim together define a housing 114 visible to Figures 3 and 4 .

The support 110 may be either an independent part driven or fixed by any other means in the frame of the watch movement, or be part of another part of the movement, such as a bridge or a plate.

In the housing 114 defined by the cup 111 and the flange 112, a pivot system 120 extending along an axis (D) is placed. This system pivot 120 comprises a circular base 121 in the form of a pellet. This base 121 may be made of a metal type material or monocrystalline type such as silicon or polycrystalline such as ceramic or ruby or sapphire.

This circular base 121, visible at the figure 3 , is a monobloc element 127 acts as a pivot element 122, that is to say that it is provided with a hole 125 blind or through which the shaft of the ax engages. Its diameter is calculated so that the tigeron that is engaged can rotate freely in with a minimum of frolicking.

The pivot system 120 also comprises elastic return means 123. These elastic return means 123 are formed by at least one curved elastic arm 124 and are attached by one of their ends to the periphery of the circular base 121. These elastic return means 123 are chosen to have a reaction force both axially and perpendicularly to the axis. That is, pivot system 120 is able to react in the event of axial impact or radial impact.

Advantageously according to the invention, the ends of the curved arms 124 which are not attached to the circular base are left free. This feature makes it possible to have a pivot system 120 which is more compact compared to the prior art system because its surface area is smaller.

Preferably, the elastic return means 123 are formed by three curved arms 124 each having a point of attachment with the base 121 and which are angularly offset by 120 °. It is obvious that the elastic function could be provided with a different number of arms 124, or with other forms.

To fix such a pivot system 120 in the support 110, the present invention advantageously proposes to use a bayonet-type fastening system as visible in FIG. figure 4 .

For this, the rim 112 has in its thickness, at least one cavity 116. This cavity 116 is formed by a clearance 117 parallel to said axis (D) and opening relative to the upper surface 113, and secant with said first clearance and opposite the upper surface 113, a blind groove 118. This groove 118 is used for bayonet immobilization of an arm 124 curved of said pivot system.

In the case where the elastic return means 113 comprise three curved arms 124, three cavities 116 are provided.

The pivot system 120 is mounted in the housing 114 so that the free ends of the bent arms 124 can be introduced into the recess 117. The pivot system can then be introduced into the housing so as to approach the bottom cup 111. . When the pivot system comes into abutment, the curved arms must face the grooves 118. Therefore, a rotational movement is made to introduce the free ends of the curved arms 124 into said grooves 118 and fix said pivot system in the support 110.

This method of fixing the pivot system 120 in the housing of the support 110 has the advantage of generating fewer constraints. Indeed, as the ends of the curved arms are free, the curved elastic arms are independent of each other because not interconnected and can more simply deform.

The geometry of the groove 118 or clearance 117 can be varied. It will be understood that the groove 118 or the clearance 117 may be cylindrical or parallelepipedal or elliptical.

Similarly, it is possible to adapt the dimensions of the clearance 117 or the groove 118 as required. For example, it is possible to have the clearance 117 which extends over all or part of the height of the flange 112. If the clearance extends over the entire height of the flange, the pivot system 120 will be, after its mounting in the support 110, in contact with the bottom of the housing 114 that is to say the In contrast, if the clearance does not extend over the entire height of the rim 112, the pivot system is no longer in contact with the cup 111. This gives it greater freedom of movement than if the clearance 117 extends over the entire height of the flange 112.

In an advantageous variant, it is intended to improve the immobilization of the pivot system 120 in the housing 114. For this, each curved arm 124 has at its free end a lug 141 extending radially relative to the central axis ( D) of the circular base 121 as visible to Figures 4 and 5 . Each blind groove 118 then has an additional recess 140 having a greater depth than that of the groove 118. This additional recess allows a lug 141 to engage.

Therefore, during the establishment of the pivot system 120, the arms 124 provided with lug 141 engage in each clearance 117 and during rotation, the difference in depth causes an elastic deformation of the arms 124. This elastic deformation is manifested by a rapprochement of the arms 124 bent towards the circular base 121. When the lug 141 located at the free end of each arm 124 arrives opposite the recess 140 of the groove 118, the stress applied to the arms 124 is releasing so that said arms tend to return to their rest position. The lug of each arm thus fits into said recess and blocks the rotation of the pivot system.

One can then imagine that clearance and the hollow have a similar depth.

In a second embodiment, the circular base 121 has a central orifice 121a (not shown) in which a pivot member 122 is housed. This configuration makes it possible to have the circular base 121 and the elastic return means 123 in a first material and the pivot element 122 in a second material. The first and second materials can be chosen according to the needs. For example, a material having elastic properties will be preferred for the arms 124 while a hard material having certain friction and wear resistance properties will be preferred for the pivot element 122.

In a first example of realization visible to figures 5 and 6 , the pivot element 122 is in the form of a single stone 127, for example ruby. This single stone 127 is placed in the orifice 121a of the circular base 121 and is provided with a blind or through hole in which the spindle of the axis engages. Its diameter is calculated so that the tigeron that is engaged can rotate freely in with a minimum of frolicking. The single stone 127 is fixed in the orifice 121a of the circular base 121 by driving or gluing or welding or any other possible methods. The advantage of this exemplary embodiment is that it makes it possible to have a pivot system 120 comprising only two parts: the single stone 127 acting as a pivot element and the circular base 121 which comprises the arms 124.

In a second example of realization visible to the figure 7 , the pivotal element comprises a kitten 128 in which are immobilized a pierced stone 129 traversed by the tibber of the axis and a counter-pivot stone 130. The kitten 128 is in the form of a tubular piece having an outer face and an inner face and an inner diameter D1. The inner face has a shoulder so that the kitten 128 has an area having a second inner diameter D2. Preferably the diameter D2 is larger than the diameter D1. This makes it possible to have the pierced stone 129 which fits into the diameter D1 and a counter-pivot stone 130 which will fit into the diameter D2 and abut against the shoulder. It is assumed, in this case, that the pierced stone 129 has a smaller diameter than that of the counter-pivot stone 130. Nevertheless, the opposite is feasible.

This kitten 128 is then placed in the orifice 121a of the circular base 121 and fixed, for example, by driving or gluing or welding. This second embodiment has the advantage of using the kitten 128 and pierced stones 129 and against pivots 130 used in a conventional shock absorber device. Second, this second example allows easier lubricant storage.

In a variant of this second embodiment, the kitten 128 and the circular base 121 are monoblock so that the pierced stone 129 and the counter-pivot stone 130 are directly immobilized in said circular base.

In a second embodiment visible to figures 8 and 9 it is envisaged to improve the absorption of axial shock. For this, the shock absorbing device according to this second embodiment further comprises an additional spring 150. This additional spring 150 is a flat spring of the lyre type, that is to say that it is in the form of an open ring comprising a hinge and two locking tabs. The hinge and the two locking tabs are diametrically opposed. Fastening areas are then created at the rim of the support to secure said additional spring. This fixing must be done so that a preload is applied to the pivot system 120. During an axial impact, a constraint is applied to the pivot system 120 via the axle spindle, the curved arms 124 deforming into result. A stress is then applied to the additional spring 150 which will deform elastically. When the stress due to the axial shock fades, the additional spring 150 tends to return to its initial position and bring back said pivot system 120 in its rest position.

It is conceivable, however, that the additional spring may be a closed annular flat spring 151 having a plurality of blades 152 extending towards the central axis of said annular spring 151. This annular spring 151 can then be glued or welded to the upper face of the rim as visible in FIG. figure 9 .

In a third embodiment visible at the figure 10 , it may be provided that the shock absorbing device 100 comprises two pivot system 120. These pivot systems are advantageously mounted in the housing 114 on support 110 by a bayonet type fixing system. For this, several possibilities are possible.

A first possibility is to use the same cavity 116 for the two pivot system 120. This cavity 116 is then formed by a clearance 117 parallel to said axis (D) and opening relative to the upper surface 113, and intersecting with said first clearance and opposite the upper surface 113, two blind grooves 118. These two grooves 118 are parallel and each of them is used for the bayonet immobilization of an arm 124 curved with a pivot system. The spacing between the two pivot systems 120 is then defined by the spacing between the two grooves 118.

A second possibility consists in having two distinct cavities 116, one for each pivot system 120. Each cavity 116 is formed by a clearance 117 parallel to said axis (D) and opening with respect to the upper surface 113, and intersecting with said first clearance and opposite the upper surface 113, a blind groove 118. This groove 118 is used for bayonet immobilization of an arm 124 curved of said pivot system. The two cavities are then configured to be angularly offset and to be located on different planes. It will be understood that during the assembly of the two pivot systems 120, a spacing appears between the two pivot systems 120.

In both possibilities, the pivot system can be all monobloc as in the figure 3 or have a kitten or a single stone inserted in the central hole 121a of the base 121. This configuration with two pivot systems also causes the most pivotal system to bottom of the housing is provided with a through hole so that the shaft of the axis can be inserted and bear on the second pivot system.

Of course, the offset angle between the two cavities may be arbitrary.

In addition, it will be understood that this third embodiment is not limited to two pivot systems 120 and a plurality of pivot system 120 can be arranged in the housing 114 of the support 110.

It will be understood that various modifications and / or improvements obvious to those skilled in the art can be made to the various embodiments of the invention described in the present description without departing from the scope of the invention.

Claims (12)

A shock absorbing device (100) for an axis of a component of a timepiece comprising a support (110) having a bottom cup (111) surmounted by a delimited peripheral rim (112), in opposition to said cup, by an upper surface (113), said cup and the flange together defining a housing (114), the device further comprising at least one pivot system (120) extending along an axis (D), said at least one a pivoting system being arranged in said housing and formed of a base (121) having resilient return means (123) at its periphery formed by at least one curved arm (124), and having an opening (121a) in which a pivot element (122) adapted to cooperate with said axis is inserted,
characterized in that the flange (112) comprises in its thickness at least one cavity (116) comprising a clearance (117) parallel to said axis (D) and opening relative to the upper surface, and secant with said first clearance and opposite the upper surface, a blind groove (118) used for the bayonet immobilization of a curved arm of said at least one pivot system. Shock absorbing device according to claim 1, characterized in that said at least one arm has a free end, said free end engaging in said at least one groove. Shock absorbing device according to claim 1, characterized in that the groove comprises a recess in which a lug located at the free end of said at least one curved arm fits. Shock absorbing device according to one of the preceding claims, characterized in that the pivot element comprises a single stone. Shock absorbing device according to one of claims 1 to 4, characterized in that the pivot element comprises a kitten in which are immobilized a pierced stone traversed by the axis of the spindle and a counter-pivot stone. Shock absorbing device according to one of claims 1 to 4, characterized in that the pivot element and the base are in one piece. Shock absorbing device according to one of the preceding claims, characterized in that the elastic return means are formed by three curved arms angularly offset by 120 °, said rim having, in its thickness, three cavities. Shock absorbing device according to one of the preceding claims, characterized in that it further comprises an additional spring allowing, in case of axial impact, to bring the axis back to its initial position. Device according to claim 8, characterized in that said additional spring is a lyre type spring in the form of an open ring comprising a hinge and two locking tabs. Device according to claim 8, characterized in that said additional spring is an annular flat spring in the form of a closed ring having axially extending bearing surfaces. Device according to one of the preceding claims, characterized in that it comprises two pivot systems (120) using the same cavity (116) for bayonet immobilization of a curved arm of each pivot system. Device according to one of claims 1 to 10, characterized in that it comprises two pivot systems (120) each using a cavity (116) for bayonet immobilization of a curved arm of said pivot system.

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