CH705584B1 - Shock-absorbing bearing for balance-sprung, balance-spiral including it, and timepiece. - Google Patents

Abstract

The invention relates to a shock-absorbing bearing (1) for a sprung balance, comprising a counter-pivoting stone (10), a hole-shaped stone (17) fulfilling the function of a sliding bearing, a frame (20) which accommodates and supports the hole stone (17), a kitten (30) which accommodates and supports the frame (20), and a fastener (37) whose ends of its outer edge are arranged to be housed in a housing present on the inner diameter (36) of the periphery of the kitten (30) and whose inner edge plate thanks to its elasticity against the pivot stone (10) against the frame (20). The contact surface of the counter-pivot stone (10) with the end of the axis of the sprung balance is of spherical shape and is convex. The invention also relates to an assembly comprising said bearing and a sprung balance, as well as a timepiece comprising such a bearing or such an assembly.

Description

Description: FIELD OF THE INVENTION [0001] The present invention relates to a damping bearing for a sprung balance, a sprung balance comprising the latter, as well as a timepiece. 2. Description of the Prior Art [0002] To reduce an axial impact (parallel to the direction in which a balance axis extends) and a transverse impact (perpendicular to the direction in which the balance axis extends ) produced, for example, by a sudden movement of a wrist of a user of a timepiece and acting on a balance-spring in the timepiece worn around the wrist, a pivot at each end of the wrist balance shaft is retained by a damping bearing. As a damping bearing of this type, it is known a damping bearing comprising a counter-pivot stone, a hole stone ("hole jewel"), a stone-to-hole kitten which carries the stones with a hole / counter-pivot, a plate cushioning which carries the kitten for stone to hole, and a support attachment piece that presses the counter-pivot stone against the stone-to-hole kitten between the cushioning plate and the stone-to-hole kitten (JP-A-2009- 139,180 (Patent Document 1) and Japanese Patent No. 4,598,701 (Patent Document 2)).

[0003] More specifically, a damping bearing 101 of this type has a structure, for example, shown in FIGS. 10, 11a and 11b and comprises a counter-pivoting stone 110 which serves the function of a thrust bearing, a hole stone 117 which serves as a journal bearing. a stone-to-hole kitten 120 having a tubular portion 121 and an enlarged-diameter portion 122, which is on the side where there is an open end 121a of the tubular portion 121, and does not carry only the counter-pivot stone 110 to the enlarged-diameter portion 122 but also the hole-shaped stone 117 in the tubular portion 121, a cushioning plate 130 which carries the stone-to-hole kitten 120, and a cushioning support fastener 137 which is disposed between the shock absorbing plate 130 and the stone kitten with hole 120 and press the counter-pivoting stone 110 against the open end portion 121a of the tubular portion 121 of the stone-to-hole kitten 120.

The damping plate 130 holds all the parts described above, as the shock absorbing support piece 137, the cushioning counter-pivoting stone 110 and the stone kitten with cushioning hole 120. More specifically, the piece of shock absorbing support bracket 137 holds the shock absorbing counter-pivot stone 110 and the shock absorbing hole stone kit 120 to absorb an impact force acting on a balance spring balance 103 and assists the counter-pivot stone 110 and the stone kitten to hole 120 not only to move (be moved) when the impact is applied but also to return to their original positions. The damping counter-pivoting stone 110 holds a balance pin 140 against a force A1 or A2 acting in the direction in which a central axial line C of the balance shaft 140 of the balance-spring 103 extends (axial direction). The shock absorbing hole stone kit 120 is a movable frame that is resiliently pressed by the support attachment 137 against the cushioning plate 130 and is movable relative to the cushioning plate when impact or other force is applied. . The stone kitten with a damping hole 120 accommodates and carries the hole stone 117 which receives a radial force B.

The damping bearing 101 retains the rocker axis 140, specifically, small diameter pivots 141F and 141R on the respective ends of the balance shaft 140 of the sprung balance 103 in a mechanical timepiece 102. In the following description, the damping bearings 101F and 101R and their parts or elements have their own reference numbers followed by a suffix F or R. When it is not necessary to distinguish the bearings and parts F and R one of the other one or collectively refer to them, the suffixes F and R are deleted.

[0006] Pivot receiving surfaces or push rod receiving surfaces 111F and 111R of the counter pivoting stones 110F and 11OR are flat surfaces. The damping bearing (which is referred to as the upper rock spring damper) 101F, which retains the pivot 141F of the balance pin 140 which is located on the rear side of the case or the side of the pendulum bridge of the timepiece 102, and the damping bearing (which is referred to as the rocker lower rock damper) 101 R, which holds the pivot 141R of the rocker pin 140 which is located on the side of the dial of the timepiece 102, are substantially configured in the same way.

The spring balance 103 comprises the rocker shaft 140, a balance rod 150, and a spring 155 and the upper and lower damping rod receivers 101F, 101R in the form of the damping bearing 101 and is attached to a pendulum bridge 105 in the rear side damper rod receptor of the casing 101 F. Each of the pendulum bridges 105 and the counterclockwise sway rod end 101R is attached to a platen 108. The spiral 155 has a spiral shape around the central axial line C of the balance shaft 140. The balance spring 155 has an inner spiral end portion attached to a collar 143 and an outer spiral end portion attached to a nail (not shown), and the effective length of the spring (spring) is adjusted by a regulator (not shown).

An exhaust regulator 104 comprising the sprung balance 103 comprises an anchor 106 and an escapement mobile 107 supported by the plate 108 and the spring balance 103. The anchor 106, specifically, a space pin 161, interacts with a plateau pin 144 of a double roll, and an entry pallet and an exit pallet (not shown) of the anchor 106 engages with an escape wheel 162 of the escape wheel 107. The escape wheel 107, specifically, a pinion 164, meshes with a second mobile 170. The second mobile 170, which operates the exhaust regulator 104 using the energy of a spring (not shown), is rotated intermittently at a predetermined rotational speed by the escape wheel 107, which is rotated intermittently at a speed defined by the balance-spring 103.

In the timepiece 102 of the prior art comprising the spring balance 103 of the prior art with the damping bearings 101F and 101R of the prior art configured in this way, when the balance spring 103 operates in an appropriate state PSO as shown in FIGS. 13a and 13b, the timepiece 2 operates normally. That is, when the rear side of the housing and the dial-side damping bearings 101F, 101R and counter-pivoting stones 110F and 11OR in the bearings 101F and 101R are arranged in such a way that the receiving flat pivot 111F and 111R counter-pivoting stones 110F and 11 OR are perpendicular to the central axial line C of the balance shaft 140 and the central axial line C of the balance shaft 140 is substantially not inclined , the balance shaft 140 is configured as explained below independently of the arrangement of the timepiece: an upward arrangement PP1 in which the damping bearing on the rear side of the housing 101F is located above the damping bearing of the 101R dial side and a downward arrangement PP2 in which the dial-side damping bearing is located above the damping bearing rear side of the housing 101 F. That is, the axis of the dial 101R lance 140, specifically, the end surfaces 145R and 145F of the pins 141R and 141F located below, more specifically, the COR and COF positions, through which the central axial line C substantially passes, come into contact with the surfaces of receiving pivot 111R and 111F of the pivoting stones 11 OR and 110F in the side of the dial and the damping bearing on the rear side of the housing 101 R, 101F located below the positions COR and COF, and the balance shaft 140 rotates with the COR and COF positions being the center of rotation. The spring balance 103 can therefore operate in substantially the same manner regardless of the attitude of the timepiece 102, PP1 or PP2, where the difference in the attitude can be minimized.

In the timepiece 102 of the prior art comprising the balance spring balance 103 of the prior art with the damping bearings 101F and 101R of the prior art, however, the state of the spring balance 103 in the timepiece 102 having the orientation or the attitude PP1 in which the damping bearing on the rear side of the housing 101F is situated above the damping bearing on the side of the dial 101R (hereinafter also referred to as "arrangement towards the high ") may differ from the state of the sprung balance 103 in the timepiece 102 having the orientation or attitude PP2 in which the damping bearing on the side of the dial 101R is situated above the damping bearing on the rear side of the box 101F (hereinafter also called "downward arrangement").

For example, as shown in FIGS. 14a and 14b, in a state PS1 in which the counter-pivoting stone 110F on the side where the rocker bridge 105 or the back of the casing is present is slightly inclined (at about a degree, for example) and attached to the kitten for 120F hole stone using the support attachment piece 137F, the condition of the sprung balance 103 in the timepiece 102 operating in an upward arrangement PP1, wherein the damping bearing 101F of the rear side of the housing is located above the damping bearing 101R on the dial side as shown in FIG. 14a differs from the state of the sprung balance 103 in the timepiece 102 operating in the downward arrangement PP2, in which the damping bearing 101R on the dial side is located above the damping bearing 101F on the rear side of the housing as shown in fig. 14b. The counter-pivoting stone 110F is inclined typically when the 120F hole stone kit is tilted to the cushioning deck 130F.

In the PS1 state, in which the counter-pivoting stone 110F attached to the side where the rocker bridge 105 is present is inclined, and in the upward arrangement PP1, in which the damping bearing 101R on the side of The dial is located below and the pivot receiving surface 111R of the counter-pivot stone 11 OR on the dial side receives the end surface of the pivot 141R of the balance shaft 140 as shown in FIG. 14a, the balance pin 140, specifically, the end surface 145R of the pivot 141R located below, more specifically, the COR position through which the central axial line C substantially passes, comes into contact with the pivot receiving surface. 111R of the counter-pivoting stone 110R in the damping bearing 101R on the dial side below the COR position, and the balance pin 140 rotates with the COR position being the center of rotation, as almost the same as shown in FIGS. 13a and 13b.

By cons, when the timepiece 102 is reversed and operates in the attitude PP2, wherein the damping bearing 101F on the side where the balance bridge 105 (back of the housing) is present is located below and the pivot receiving surface 111F of the counter-pivoting stone 110F on the side where the balance bridge 105 is present receives the end surface of the pivot 141F of the balance shaft 140 as shown in FIG. 14b, the balance shaft 140, specifically, the end surface 145F of the pivot 141F located below, more specifically, an edge CaF which is separated from the central axial line C and situated on the same side as the side in the direction of which the counter-pivoting stone 110 is inclined, comes into contact with the pivot receiving surface 111F of the counter-pivoting stone 110F in the damping bearing 101F located on the side where the balance bridge 105 is present and below the edge CaF, unlike the boxes shown in Figs. 13a, 13b and FIG. 14a. The center of rotation of the balance shaft 140 is therefore a point CaF (Ca) which is not on the central axial line C of the balance shaft 140 but is separated from the central axial line C by Apr ( the distance corresponding to the radius of the pivot 141 and to several tens of micrometers), resulting in an unstable axis of rotation.

As seen in the description above, in the state PS1, the operation of the sprung balance 103 in the timepiece 102 operating in the upward arrangement PP1 differs from the operation of the sprung balance. 103 in the timepiece 102 operating in the downward arrangement PP2. In this case, a considerable difference in the speed of the timepiece is inevitable.

In addition, for example, as shown in FIGS. 15a and 15b (Fig. 15b in particular), in the downward arrangement PP2 and in a case PS2 where the central axial line C of the rocker axis 140 is inclined, the rocker axis 140, specifically, the surface end 145F of the pivot 141F below, more specifically, the edge CaF which is separated from the central axial line C and located on the same side as the side towards which the central axial line C of the balance shaft 140 is inclined, comes into contact with the pivot receiving surface 111F of the counter-pivoting stone 110F in the damping bearing 101F located on the side where the balance bridge 105 is present and below the edge CaF, as in the case PS1 shown in figs. 14a and 14b. The center of rotation of the balance shaft 140 is therefore the point CaF (Ca) which is not on the central axial line C of the balance shaft 140 but is separated from the central axial line C by Apr ( the distance corresponding to the radius of the pivot 141 and to several tens of micrometers), resulting in an unstable axis of rotation.

In the PS2 state described above, the operation of the spring balance 103 in the timepiece 102 operating in the upward arrangement PP1 also differs from the operation of the balance spring balance 103 in the workpiece timepiece 102 operating in the downward arrangement PP2, and a considerable difference in the rate ("rate") of the timepiece is inevitable.

The central axial line C of the balance shaft 140 may be inclined, for example, when the weight of the balance rod 150 is not balanced in the circumferential direction. Strictly speaking, for example, the central axial line C of the rocker axis 140 is inclined somewhat and the inclination varies somewhat when a torque is applied to the rocker axis 140 by the flange 143 during an operation. winding or releasing the hairspring 155 having a spiral spring shape.

In addition, as shown in FIGS. 16a and 16b, in a state PS3 in which the end surface 145F of the pivot 141F on the side where the balance bridge 105 is present is inclined to the central axial line C of the balance shaft 140 and in the downward arrangement PP2, the end surface 145F, specifically, the CaF edge protruding because the end surface 145F is inclined, comes into contact with the pivot receiving surface 111F of the backstop stone 110F in the damping bearing 101F located on the side where the balance bridge 105 is present and below the edge CaF. The center of rotation of the balance shaft 140 is therefore the point CaF (Ca) which is not on the central axial line C of the balance shaft 140 but is separated from the central axial line C by Apr ( the distance corresponding to the radius of the pivot 141 and about several tens of micrometers), resulting in an unstable axis of rotation.

In the PS3 state described above, the operation of the spring balance 103 in the timepiece 102 operating in the upward arrangement PP1 also differs from the operation of the spring balance 103 in the workpiece timepiece 102 operating in the downward arrangement PP2, and a considerable difference in the rate of the timepiece is inevitable.

On the other hand, to reduce the possibility of the difference in the rate of the timepiece 102 between the upward arrangement PP1 and the downward arrangement PP2 due to the variety of reasons described hereinabove. above, the following proposition has been made: the end flat surfaces 145F and 145R of the pins 141F and 141R on the balance shaft 140 are replaced by a convexly curved end surface or by pivot points 145F and 145R.

However, since the diameter of each of the pins 141F and 141R is typically greater than about 0.1 mm, it is difficult to maintain a high precision of the dimensions of the shape of such a convexly curved surface. When the variation in the length of the pivots, in other words, the length of the balance shaft 140, increases with the variation in the shape of the convexly curved surface, the shape of the spiral 155 tends to differ between the upward arrangement PP1 and the downward arrangement PP2. It is therefore difficult to eliminate the possibility of increasing the difference in the rate of the timepiece, because the spiral 155 which should extend spirally in a plane perpendicular to the central axial line C of the balance shaft 140 has, for example, a shape somewhat similar to a funnel and therefore the change in the characteristics of the spring when the timepiece operates in the upward arrangement PP1 or the downward arrangement PP2. SUMMARY OF THE INVENTION [0022] The invention has been made in view of the points described above. An object of the invention is to provide not only a damping bearing for a balance spring which can minimize the variation in the operation of the balance with the balance due to the variation in the support state of a balance shaft but also a sprung balance including the damping bearing and a timepiece including the damping bearing.

To achieve the object described above, a damping bearing for a sprung balance according to the invention comprises a counter-pivot stone which performs the function of a thrust bearing, a hole stone that performs the function of a plain bearing, a stone kitten with a hole that houses the hole stone and carries the hole stone, a cushioning plate that houses the kitten for stone to hole, carries the kitten for a hole stone and includes a retaining part on the side where there is a large diameter open end and a support attachment piece having an outer rim retained by the cushioning portion of the cushioning plate and an inner rim resiliently pushing the counter-pivot stone against the stone kitten hole for holding the counter-pivot stone, and the surface of the counter-pivot stone which is arranged to oppose an end surface of a rod retained by the damping bearing and to come into contact with the surface this end of the rod is a convexly curved surface projecting outwards.

In the damping bearing for a sprung balance according to the invention, since "the surface of the counter-pivot stone which opposes the end surface of a rod retained by the damping bearing and comes into contact with the end surface of the stem is formed of a convexly curved surface protruding outwards', even when none of the following types of inclination occur: the counter-pivot stone held by the stone for hole stone and the bracket attachment piece is tilted; the central axial line (line of gravitation) of the stem is inclined; and the end surface of the shank is tilted, the amount of change in the position of a rotational support portion due to any of the types of inclination described above is minimized compared to a case where the surface the counter-pivot stone which opposes the end surface of a rod retained by the damping bearing and comes into contact with the end surface of the rod "is a" flat surface ". Therefore, an opposite effect of a timepiece arrangement, for example, on the rate of this can be minimized. Further, since "the surface of the counter pivot stone (a pivot receiving surface) is formed of a convexly curved surface projecting outwards", the counter pivot stone substantially contacts a only point and supports the end surface of the rod to be rotatably supported, where the rod tends to rotate stably. In this case, since the end surface of an end portion or the tip (tip of the pivot) of the end portion (pivot portion) of the rod (balance shaft) to be supported by the damping bearing for a balance spring can be a flat surface, a variation in the length of the rod (balance shaft) can be minimized.

In the damping bearing for a sprung balance according to the invention, the convex surface of the counter-pivot stone may be formed of a spherical surface portion.

In this case, it is likely that the convex surface of the counter-pivot stone is formed in an exact, highly accurate manner. The convex surface may have another shape which is a spheroid including a spherical surface in a broad sense, as desired. The convex surface can not be rotatably symmetrical as long as the convex surface has a smooth curved shape, convex outwardly. It should be noted, however, that the convex surface is preferably a partially spherical surface (spherical surface portion) for minimizing the opposing effect of variation in the support state of the balance shaft, such as the tilt of the counter-pivot stone, on the rate or any other operation of the sprung balance (variation in the operation).

The damping bearing for a sprung balance according to the invention may be such that the counter-pivot stone has a convex lens-like shape, that the hole-shaped stone kit includes a tubular part and a widened-diameter portion of the on the side where an open end of the tubular portion is located, that the enlarged diameter portion carries the counter-pivot stone, that the outer rim of the support attachment piece is retained by the cushioning portion of the cushioning plate, and the inner rim of the support fastener resiliently urges the counter-pivot stone against the enlarged diameter portion of the stone-to-hole kit to hold the counter-pivot stone.

In this case, even when the thickness of the damping bearing is minimized and the end surface of the rod which opposes the bearing is a flat surface, a variation in the operation of the sprung balance due to the variation in the support state of the balance shaft can be minimized, and a variation in the operation due to a difference in attitude, such as an upward disposition and a downward disposition, can be minimized .

In another typical example of the damping bearing for a sprung balance according to the invention, the counter-pivot stone is a sphere.

In this case, the counter-pivot stone can be formed in a highly precise manner in terms of dimension, where the variation in the operation of the sprung balance can be minimized.

In addition, in one embodiment of the damping bearing for a sprung balance according to the invention, the spherical counter-pivot stone is arranged in such a manner in a cylindrical zone of the stone-to-hole kitten that the counter-stone pivot can contact the hole stone, while the outer edge of the support fastener is retained by the cushioning portion of the cushioning plate, and the inner edge of the support fastener pushes the stone counter-pivoting against a terminating end surface of the hole-shaped stone in the cylindrical zone of the stone-to-hole chaton for resiliently pushing the counter-pivot stone against the hole-to-hole chaton via the hole-shaped stone and holding the counter-pivot stone .

In this case, an advantage of the fact that the counter-pivot stone is formed of a sphere (ball) can be provided while the increase in thickness resulting from the fact that the counter-pivot stone is formed of a sphere (ball) is minimized.

In the damping bearing for a sprung balance according to the invention, the portion of the stone kitten with hole which supports a pivot receiving surface of the counter-pivot stone may have a truncated cone shape.

In this case, the variation in the operation of the sprung balance can be minimized. The truncated cone shape can be replaced with a spherical shape.

The invention also relates to a sprung balance comprising any damping bearing among those defined above.

In the sprung balance according to the invention, the rod retained by the damping bearing may be a balance shaft, and the end surface of a pivot, which is located at each end of the balance shaft and has a diameter smaller than the diameter of a main part of the balance shaft, can be substantially a flat surface.

In this case, the length of the balance shaft can be cut to the right dimensions in a highly accurate manner, and a variation in the rate of a timepiece due to the arrangement of the workpiece. a clockwise, upward and downward arrangement can be minimized.

To achieve the purpose described above, a timepiece according to the invention comprises any damping stage among those defined above or any sprung balance among those defined above.

Brief description of the drawings [0039]

Fig. 1 is a sectional descriptive diagram showing a part of a timepiece of a preferred example according to the invention comprising a spiral balance of the preferred example according to the invention with a damping bearing of the preferred example according to the invention.

Fig. 2 represents the damping bearing for the sprung balance shown in FIG. 1, fig. 2a being a descriptive diagram in plan and FIG. 2b is a sectional descriptive diagram.

Fig. 3 is a sectional descriptive diagram showing a state in which an end portion comprising a pivot of a balance shaft is installed in the damping bearing for the sprung balance shown in FIG. 1.

Fig. 4 represents a case where a counter-pivot stone on the side of the balance bridge is inclined in the damping bearing for the sprung balance in the timepiece shown in FIG. 1, fig. 4a being a sectional descriptive diagram showing the damping bearing for the sprung balance and the two end parts including pivots of the balance shaft in the timepiece operating in an upward arrangement and FIG. 4b is a sectional descriptive diagram showing the damping bearing for the sprung balance and the two end portions comprising the pivots of the balance shaft in the timepiece operating in a downward arrangement.

Fig. 5 represents a case where one of the pivots of the balance shaft is inclined in the damping bearing for the sprung balance in the timepiece shown in FIG. 1 operating in the downward arrangement, FIG. 5a being a sectional descriptive diagram showing the damping bearing for the sprung balance and the two end portions representing the pivots of the balance shaft in the timepiece operating in the upward arrangement and FIG. 5b is a sectional descriptive diagram showing the damping bearing for the sprung balance and the two end portions representing the pivots of the balance shaft in the timepiece operating in the downward arrangement.

Fig. 6 represents a case where the end surface of one of the pivots of the balance shaft, specifically the pivot on the side of the balance bridge, is inclined in the damping bearing for the sprung balance in the timepiece represented in FIG. fig. 1, fig. 6a being a sectional descriptive diagram showing the damping bearing for the sprung balance and the two end portions comprising the pivots of the balance shaft in the timepiece operating in the upward arrangement and FIG. 6b being a sectional descriptive diagram showing the damping bearing for the sprung balance and the two end portions comprising the pivots of the balance shaft in the timepiece operating in the downward arrangement.

Fig. 7 shows a damping bearing of another preferred example according to the invention, FIG. 7a being a descriptive diagram in plan and FIG. 7b being a sectional descriptive diagram.

Fig. 8 is a sectional descriptive diagram showing a portion of a sprung balance of another preferred example according to the invention showing a state in which an end portion comprising a pivot of a balance shaft is installed in the bearing damper shown in FIG. 7.

Fig. 9 shows the degree of change in a position of the center of rotation under a variety of conditions in the sprung balance provided with the damping bearing shown in FIG. 7, FIG. 9a being a sectional descriptive diagram showing a standard case where the balance shaft and the counter-pivot stone operate in a predetermined state, FIG. 9b is a sectional descriptive diagram showing a case where the counter-pivot stone is inclined, and FIG. 9c being a sectional descriptive diagram representing a case where the balance axis is inclined.

Fig. 10 is a sectional descriptive diagram showing a part of a timepiece of the prior art comprising a sprung balance of the prior art with a damping bearing of the prior art.

Fig. 11 shows the damping bearing of the prior art in the timepiece shown in FIG. 10, FIG. 11a being a descriptive diagram in plan and FIG. 11 b being a sectional descriptive diagram.

Fig. 12 is a sectional descriptive diagram showing a state in which an end portion comprising a pivot of a balance shaft is installed in the damping bearing for the sprung balance shown in FIG. 10.

Fig. 13 shows the state in which the damping bearing for the sprung balance in the timepiece shown in FIG. 10 can operate normally, FIG. 13a being a sectional descriptive diagram showing the damping bearing for the sprung balance and the two end portions comprising pivots of the balance shaft in the timepiece operating in an upward arrangement and FIG. 13b is a sectional descriptive diagram showing the damping bearing for the sprung balance and the two end portions comprising the pivots of the balance shaft in the timepiece operating in a downward arrangement.

Fig. 14 shows a state in which a counter-pivot stone on the balance bridge side is inclined in the damping bearing for the sprung balance in the timepiece shown in FIG. 10, FIG. 14a being a sectional descriptive diagram showing the damping bearing for the sprung balance and the two end portions comprising the pivots of the balance shaft in the timepiece operating in the upward arrangement and FIG. 14b is a sectional descriptive diagram showing the damping bearing for the sprung balance and the two end portions comprising the pivots of the balance shaft in the timepiece operating in the downward arrangement.

Fig. 15 shows a state in which one of the pivots of the balance shaft is inclined in the damping bearing for the sprung balance in the timepiece shown in FIG. 10 operating in the downward arrangement, FIG. 15a being a sectional descriptive diagram showing the damping bearing for the sprung balance and the two ends comprising the pivots of the balance shaft in the timepiece operating in the upward arrangement and FIG. 15b is a sectional descriptive diagram showing the damping bearing for the sprung balance and the two ends comprising the pivots of the balance shaft in the timepiece operating in the downward arrangement.

Fig. 16 shows a state in which the end surface of one side of the balance beam of the pivots of the balance shaft is inclined in the damping bearing for the sprung balance in the timepiece shown in FIG. 10, FIG. 16a being a sectional descriptive diagram showing the damping bearing for the sprung balance and the two end portions comprising the pivots of the balance shaft in the timepiece operating in the upward arrangement and FIG. 16b being a sectional descriptive diagram showing the damping bearing for the sprung balance and the two end portions comprising the pivots of the balance shaft in the timepiece operating in the downward arrangement.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0040] A preferred embodiment of the invention will be described with reference to a preferred example shown in the accompanying drawings.

Example [0041] FIG. 1 represents a part of a timepiece 2 of a preferred example according to the invention comprising a balance spring 3 of the preferred example according to the invention with a damping bearing 1 of the preferred example according to the invention . Figs. 2a and 2b are enlarged views showing the damping bearing 1 in the timepiece 2. FIG. 3 is an enlarged view showing a portion of the side of the end of a balance shaft of the balance spring 3 comprising the damping bearing 1.

In the mechanical timepiece 2, an exhaust regulator 4 comprises the balance spring 3, an anchor 6, and an escapement mobile 7. The timepiece parts 3, 6, and 7, which form the exhaust regulator 4, are carried by a plate 8. The anchor 6, specifically, a space pin 61, interacts with a plateau pin 44 of a double cylinder, and an entry pallet and a output pallet (not shown) of the anchor 6 interact with an escape wheel 62 of the escape mobile 7. The escape mobile 7, specifically, a pinion 64, meshes with a second mobile 70. The second mobile 70, which actuates the escape wheel 7 in the exhaust regulator 4 using the energy of a spring (not shown), is rotated intermittently at a predetermined rotational speed by the escape wheel 7, which is rotated intermittently ittence at a speed defined by the spring balance 3.

The spring balance 3 comprises a balance shaft 40, a balance beam 50 and a balance spring 55. The balance shaft 40, specifically, 41F and 41 R pivots, which are small end portions. upper and lower diameter (rear side of case and side of dial), are rotatably supported by upper and lower damping stem receivers in the form of damping bearing or an upper stone damper for 1F rocker arm and a lower stone damper for a pendulum 1 R. The end surfaces of 45F and 45R of the pivots 41F and 41R are flat surfaces substantially perpendicular to a central axial line C. Since the configuration described above allows the lengths of the pivots to be accurately cut. compared with the case where the end surfaces or pivot points of the pivots are convexly curved surfaces, the length and shape of the balance shaft 40 can be accurately cut and formed, where variation in assembled pivot points can be minimized.

In the following description, the damping bearings 1F and 1R and parts or elements thereof have their own reference numbers followed by a suffix F or R. When it is not necessary to distinguish the bearings and parts F and R of each other or a collective reference is made, the suffixes F and R are omitted.

The lower stone damper for the balance, that is to say, the lower damping bearing or the dial side 1R is attached to the plate 8, and the upper stone damper for the balance, c that is, the upper damping stem receiver or the rear side of the housing 1F is attached to the plate 8 by a rocker bridge 5. The rocker shaft 40 has end-side rods 42F and 42R located in more intermediate portions than the pivots 41F and 41R and having diameters greater than those of the pivots 41F and 41R but smaller than those of the other parts of the balance shaft 40. The spiral 55 has a spiral shape around of the central axial line (axis of gravitation) C of the balance shaft 40. The balance spring 55 has an inner side spiral end portion attached to a ferrule 43 and an outer side spiral end portion attached. to a nail (not shown), and along The effective spring (spring) is adjusted by a regulator (not shown).

[0046] The upper and lower damping stem receivers 1F, 1R have substantially the same structure and shape and are therefore described as the damping bearing or damping stem receiver 1 as long as it is not necessary to distinguish them from each other. one of the other.

The stone damper for a rocker arm or the damping rod receiver, that is to say, the damping bearing 1 comprises a counter-pivot stone or a damping counter-pivot stone 10 which performs the function of a thrust bearing, a hole-shaped stone 17 which performs the function of a plain bearing, a stone-to-hole kitten or a stone kitten with a cushioning hole 20 which carries the hole-shaped stone 17, a damping plate 30 which carries the counter-pivot stone 10 and the stone-to-hole kitten 20, and a support attachment piece or a cushioning support attachment piece 37.

The damping bearing 1 retains the balance pin 40, specifically, the small diameter pivots 41F and 41R at the respective ends of the balance shaft 40 of the balance spring 3 in the mechanical timepiece 2. The Pivot receiving surfaces or thrust rod receiving surfaces 11F and 11R of the counter pivot pins 10F and 10R each have a partially spherical shape (part of a spherical surface having a wide radius). The pivot receiving surfaces 11F and 11R of the backstop stones 10F and 10R are not necessarily a partially spherical surface (part of a spherical surface having a wide radius) but may be any other surface that is convex outwardly , curve smoothly (convex surface), and alternately symmetrical.

The counter pivot stone 10 has partially spherical end surfaces 11 and 12 similar to those of a convex lens, as described above. When the partially spherical end surfaces 11 and 12 have the same shape, it is not necessary to identify the orientation of the counter-pivot stone 10, i.e., whose side is in front or behind, at the time of assembly. It should be noted, however, that the end surface 12 may be alternately a spherical surface having a different or flat diameter or other suitable surface instead of a partially spherical surface. The shock absorbing counter-pivot stone 10 receives a force A1 or A2 (simply with reference to a force in a direction A when the forces do not need to be distinguished from each other or are collectively referred to) in the direction in which the central axial line C of the balance shaft 40 of the spring balance 3 extends (axial direction).

The hole stone 17, which is substantially plate-shaped, has a pivot hole 18 in the center and an outer circumferential cylindrical surface 17a. A recess 17c for guiding a pivot to the pivot hole 18 is formed in one of the end surfaces, an end surface 17b. The other end surface 17d is typically a flat surface. It should be noted, however, that the end surface 17d may be curved in such a concave manner in some cases that adequate space is easily maintained between the counter pivot stone 10 and the convex surface 11.

The damping plate 30 comprises a small-diameter tubular portion 31, a large-diameter tubular portion 32, an end-end neck portion 33 with an end-end stem receiving hole 33a. wherein the end-side shank 42 of the balance shaft 40 is loosely installed, a binder-like portion 34, inclined surface portions 35a and 35b, and an inward retention portion 36. The end-end neck portion 33 is formed at one end of the small-diameter tubular portion 31, and the large-diameter tubular portion 32 is larger in diameter than the small-diameter tubular portion 31 and at one end connected to another end of the small-diameter tubular portion 31 by the binder-neck portion 34. The inward-holding portion 36 is formed at the other end of the tubular portion. The end-end shank hole 33a has a diameter slightly larger than the diameter of the end-end shank 42 of the balance shaft 40. The inclined surface portions 35a are of a larger diameter. and 35b each have the shape of the outer circumferential surface of a truncated cone and are typically arranged so similarly and linearly as to form a portion of the outer circumferential surface of a single truncated cone imaginarily. The inclined surface portion 35a is formed at one end of the end side shank receiving hole 33a in the end side neck portion 33, and the inclined surface portion 35b is formed in the tubular portion. small diameter 31, specifically, in the vicinity of the binder neck portion 34.

The stone-to-hole kitten 20 comprises a small diameter tubular portion 21, a large-diameter tubular portion 22 as an enlarged diameter portion, an annular plate-shaped end-side collar portion 23 a truncated cone-shaped end-side neck-shaped portion 24 with an end-side shank receiving hole 24a in which the end-side shank 42 of the balance shaft 40 is installed with play, a tie-shaped portion 25, and inclined surface portions 26a and 26b. An inner circumferential surface 21a of the small diameter tubular portion 21 has a cylindrical shape, and the hole stone 17 is installed in the small-diameter tubular portion 21. The plate-shaped end-end collar portion annular 23 is formed at one end of the small-diameter tubular portion 21, and the truncated cone-shaped end-end collar portion 24, specifically, an end portion of the large-diameter side thereof, is connected to a radially inner end portion of the annular plate end-end-shaped collar portion 23 and extends to an end-end-end receiving hole end portion which defines the end side shank receiving hole 24a. An inner end surface 23a of the annular plate end-end-shaped neck portion 23 is a flat surface and contacts the end surface 17b of the hole stone 17, which is installed in the tubular portion. small diameter 21, to support the hole stone 17. The large diameter tubular portion 22 is larger in diameter than the small diameter tubular portion 21 and has one end connected to the other end of the tubular portion of small diameter 21 by the binder collar portion 25. An inner surface 25a of the binder collar portion 25 as an open end portion of the tubular portion 21 has a truncated cone shape and contacts an outer portion of the surface similar to a convex lens of partially spherical end 11, which is the pivot receiving surface 11 of the counter pivot stone 10, to support the counter pivot stone 1 0, specifically, the partially spherical end surface 11. The end side shank receiving hole 24a is slightly larger in diameter than the end side shank 42 of the balance shaft 40. The surface portions 26a and 26b each have the shape of the outer circumferential surface of a truncated cone and are typically arranged so similarly and linearly as to form part of the outer circumferential surface of a single imaginary truncated cone. When the hole stone kitten 20 is disposed in a predetermined position in the cushion plate 30, the inclined surface portions 26a and 26b of the hole stone box 20 contact the inclined surface portions 35a and 35b of The inclined surface portion 26a is formed along an outer circumferential surface of the truncated cone-shaped end-edge-shaped end portion 24, and the inclined-surface portion 26b is formed on the outside. along the large diameter tubular portion 22, specifically, the outer circumferential surface of an end portion in the vicinity of the binder neck portion 25.

The shock absorbing support fastener 37 has a shape similar to a three-leaf clover. The retaining portions 38a, 38a, 38a protruding from a large diameter portion 38 engage with the inwardly retaining portion 36 of the cushioning plate 30, and the U-shaped retaining portions 39, 39, 39, extending inwardly in the radial direction engage with the outer end surface 12 of the counter pivot stone 10. The damping support mounting piece 37 thus pushes the counter pivot stone 10 against the inner surface 25a. of the binder collar portion 25 of the stone kitten 20. The cushioning support fastener 37 thus pushes the stone-to-hole kitten 20, specifically, the inclined surface portions 26a and 26b, by the stone -pivot 10 against the inclined surface portions 35a and 35b of the cushioning plate 30. The cushioning support attachment piece 37 does not have to be shaped like a three leaf clover but can have any other shape capable of pushing the counter pivot stone 10.

The shock absorbing support fastener 37 therefore elastically holds the shock absorbing counter-pivot stone 10 and the shock absorbing hole stone kitten 20 to absorb an impact pressure acting on the body of the balance-spring 3 and allows the counter pivot stone 10 and the hole stone kitten 20 to move when the impact is applied and to return to their original positions. When a user wears the timepiece 2 in the shape of a wristwatch around a wrist, and the user suddenly moves the wrist to exert an axial impact on the balance shaft 40, the axial force ( impact) acting on the balance pin 40 causes the pivoting stone 10, specifically, the pivot receiving surface 11, to receive a force in the direction A from the end surface (pivot point) 45 of the pivot 41, and the counter pivot stone 10 is allowed to be moved in the direction A to absorb the impact and to protect the pivot 41. Moreover, when the user moves the wrist abruptly, and a transverse impact (in the direction perpendicular to the axial direction) acts on the balance shaft 40 and a force (impact) in the direction perpendicular to the central axial line C acts on the balance shaft 40, a force from the pivot 41 in the transverse direction acts on the pihole 18. Therefore, the hole stone kitten 20 is moved against the spring force produced by the support attachment piece 37 along the surface where the inclined surfaces 26a and 26b of the hole stone kit 20 ' engage with the inclined surfaces 35a and 35b of the damping plate 30, where the impact is absorbed and the pivot 41 is protected. In either case, when the impact is eliminated, the force produced by the support attachment piece causes the stone-to-hole kitten 20 to return somewhat to its original position.

In the mechanical timepiece 2 of the preferred example according to the invention comprising the balance spring 3 of the preferred example according to the invention with the damping bearings 1F and 1R of the preferred example according to the invention. invention configured in this manner, a description will be made in detail of whether or not there is a difference and the degree of difference if there is any between a case where the timepiece 2 operates in a "disposition towards the P1 in which the damping bearing on the rear side of the housing 1F is located above the damping bearing 1R on the side of the dial and a case where the timepiece 2 operates in a "downward arrangement" P2 in which the The damper bearing 1R on the dial side is located above the damping bearing 1F on the rear side of the housing under a variety of conditions with reference to FIGS. 4a and 4b, in figs. 5a and 5b, and in FIGS. 6a and 6b.

When the counter-pivoting stones 10F and 10R are arranged substantially perpendicular to the central axial line C of the balance shaft 40 of the balance spring 3, and the partially spherical receiving surfaces 11F and 11R are symmetrical to rotatively in accordance with the central axial line C, the support state of the balance shaft 40 of the balance-spring 3 is substantially the same in the following two cases: the case where the timepiece 2 operates in the upward arrangement P1 and the case where the timepiece 2 operates in the downward arrangement P2, where there is no practical difference in the rate of the timepiece between the upward arrangement P1 and the downward arrangement P2, as in the prior art. In the balance-spring 3, since the pivot receiving surfaces 11F and 11R of the counter-pivoting stones 10F and 10R are partially spherical surfaces, the pivot receiving surfaces 11F and 11R each come into substantially one-point contact with each other. the end surfaces 45F and 45R of the pivots 41F and 41R of the balance shaft 40, where the balance shaft 40 tends to rotate stably.

In a state S1 in which the counter-pivot stone 10F on the side where the pendulum bridge 5 or the back of the housing is present is slightly inclined (at about a degree, for example) and attached to the stone kitten with hole 20 using the support fastener 37F as shown in FIGS. 4a and 4b, the state of the sprung balance 3 differs in a precise direction somewhat between the case where the timepiece 2 operates in the upward arrangement P1 as shown in FIG. 4a and the case where the timepiece 2 operates in the downward arrangement P2 as shown in FIG. 4b. The counter-pivoting stone 10F is typically inclined when the inclined surfaces 26a and 26b of the stone-to-hole chaton 20F do not engage with the inclined surfaces 35a and 35b of the cushioning plate 30F and hence the stone-to-hole chaton. 20F is inclined towards the damping base 30F. The situation described above (the state of the sprung balance differs between the case where the timepiece operates in the upward arrangement and the case where the timepiece operates in the downward arrangement) itself. same is the same as the situation in the description made in association with the timepiece 102 of the prior art comprising the balance spring balance 103 of the prior art with the damping bearings 101F and 101R of the prior art with reference in figs. 14a and 14b, but the degree of the difference in the state of the sprung balance between the upward and the downward disposition differs between the timepiece 2 and the timepiece 102 of the prior art .

That is to say, when the timepiece 2 operates in the state S1, in which the counter-pivot stone 10F on the side where the balance bridge 5 is present is inclined and attached, and in the upward arrangement P1, wherein the damping bearing 1R on the dial side is located below and the counter pivoting stone on the dial side 10R, specifically, the pivot receiving surface 11R thereof, receives the surface end 45R of the pivot 41R of the balance shaft 140 as shown in FIG. 4a, the balance pin 40, specifically, the end surface 45R of the pivot 41R located below, more specifically, the COR position through which the central axial line C passes, comes into contact with the partially spherical pivot receiving surface 11R of the counter pivot stone 10R in the dial side damping bearing 1R located below the COR position, and the balance pin 40 rotates about the central axial line C with the contact position COR being the center of rotation, which is practically the same as the case shown in FIG. 14a. That is, in the inclination variation described above, there is no adverse effect due to the situation in which the counter-pivot stone 10F on the side where the pendulum bridge 5 or the rear of the housing is present is slightly inclined (to about one degree, for example) and attached to the stone-to-hole kitten 20F by the support attachment piece 37F, as substantially the same as the case shown in FIG. . 14a. In an exact sense, however, since the pivot receiving surface 11R of the counter pivoting stone 10R is convexly curved in the timepiece 2, the timepiece 2 may differ from the timepiece 102. in which the position COR on the central axial line C becomes firmly the center of rotation.

On the other hand, when the timepiece 2 is reversed and operates in the downward arrangement P2, wherein the damping bearing 1F on the side where the balance bridge 5 (rear of the housing) is present is located below and the pivot receiving surface 11F of the pivoting stone 10F on the side where the balance bridge 5 is present receives the end surface 45F of the pivot 41F of the balance shaft 40 as shown in FIG. fig. 4b, even though the contour of the pivot receiving surface 11F in the vicinity of the central axial line C deviates somewhat, the contour of the pivot receiving surface 11F is still substantially the same as that of before the inclination about one degree occurs, as indicated by the ghost line in fig. 4b. In particular, when the backstop stone 10F is inclined at about one degree, a portion CaV of the pivot receiving surface 11F where the tangential line is perpendicular to the central axial line C substantially coincides with the position where the central axial line C crosses the receiving surface 11F. That is, assuming the 10F counter pivot stone is tilted because the 20F hole stone kit does not engage with the cushioning base 30 (surfaces 26a and 26b do not engage with the surfaces 35a and 35b), and that the one-degree rotation turns the pivot receiving surface 11F in a substantially one-degree circumferential direction, the orientation of the tangential plane to the COF portion of the pivot receiving surface. 11F where the central axial line C crosses the pivot receiving surface 11F is substantially unchanged. Therefore, the CaV portion of the pivot receiving surface 11F where the tangential plane is perpendicular to the central axial line C is barely displaced from the COF position where the central axial line C intersects the receiving surface 11F. Therefore, at the point CaV located on the end surface 45F of the pivot 41F located below, specifically located in the vicinity of the position through which the central axial line C passes, the balance shaft 40 comes into contact with the surface for receiving the partially spherical pivot pin 11F of the pivoting stone 10F in the damping bearing on the dial side 1F located below the point CaV and rotating around the central axial line C with the position CaV being the center of rotation. The same is true for a case where the pivot receiving surface 11F is moved along the truncated cone-shaped inner surface 25a of the binder collar portion 25 of the stone-to-hole chaton 20F.

That is to say, when the mechanical timepiece 2 comprising the spring balance 3 provided with the damping bearings 1F and 1R having convexly curved pivot receiving surfaces partially spherical 11F and 11R operate. in the state S1 in which the backstop stone 10F on the side where the balance bridge 5 or the back of the housing is present is slightly inclined (at about a degree, for example) and attached to the stone-to-hole kitten 20F using the support fixing piece 37F as shown in FIGS. 4a and 4b, the state of the spring balance 3 differs somewhat between the case where the timepiece 2 operates in the upward arrangement P1 shown in FIG. 4a and the case where the timepiece 2 operates in the downward arrangement P2 shown in FIG. 4b in an exact sense. In practice, however, even in the downward arrangement P2, the part where the partially spherical convexly pivoted receiving surface 11F in the damping bearing 41F comes into contact with the end surface 45F of the axis pivot 1F. The difference in the rate of the timepiece is therefore considerably smaller than in the case shown in FIGS. 14a and 14b because the sprung balance 3 can operate both in substantially the same manner in the upward arrangement P1 and the downward arrangement P2.

On the other hand, as shown in FIGS. 5a and 5b (Fig. 5b in particular), in the downward arrangement P2 and in a state S2 in which the central axial line C of the balance shaft 40 is inclined somewhat (about 0.2 degrees, for example ), the end surface 45F of the pivot 41F of the balance shaft 40 comes into contact with the pivot receiving surface 11F, specifically, a portion Cb separated from the central axial line C of the balance shaft 40 somewhat , counter pivot stone 10F in the damping bearing 1F located on the side where the balance bridge 5 is present and located below the part Cb. The part Cb corresponds to a part where the plane tangential to the pivot receiving surface 11F of the counter pivot stone 10F is parallel to (coincides with) the end surface 45F of the pivot 41F of the balance shaft 40 having the line central axial inclined C.

The center of rotation Cb of the balance shaft 40 is therefore located in a position which is not on the central axial line C of the balance shaft 40 but is separated from the portion through which the central axial line C passes through Ar (which represents a portion of the radius of the pivot 41 and about 10 pm), and the balance shaft 40 rotates with the point Cb being the center of rotation.

In the state S2, the operation of the spring balance 3 substantially differs between the timepiece 2 operating in the upward arrangement P1 and the timepiece 2 operating in the downward arrangement P2, and there is a somewhat inevitable difference in the rate of the timepiece. It should be noted, however, that the amount of change in the center position Cb from the center C in the downward arrangement P2 is about a portion of the radius of the pivot 41 of the balance shaft 40, where the difference in the rate of the timepiece between the downward arrangement P2 and the upward arrangement P1 can be considerably reduced compared with the difference in the timepiece 102 of the prior art in which the momentum is about the radius of the pivot 41 of the balance shaft 40 (Fig. 15b).

A variety of causes results from an inclination of the central axial line C of the balance shaft 40. That is to say, when the central axial line C of the balance shaft 40 is inclined, the possibility of a great difference in the rate of the timepiece can be reduced independently of the attitude of the timepiece 2 compared with the timepiece 102 of the prior art. As an example of the inclination described above, the balance rod 50 is inclined, for example, because the weight of the balance rod 50 is not balanced. Strictly speaking, the axis of the central axial line C of the balance shaft 40 may be somewhat inclined, for example, because of a force acting on the balance shaft 40 from the spiral 55 by the ferrule 43 when the hairspring 55 is armed or released. Even in the case described above, in the sprung balance 3 having damping bearings 1, provided on the respective ends of the rocker shaft 40, each of the pivot receiving surfaces 11 is a partially spherical surface unlike the balance wheel -spiral 103 of the prior art in which each of the pivot receiving surfaces 111 is a flat surface, the end surface 45 of the pivot 41 of the balance shaft 40, specifically, a portion in the vicinity of the central axial line C, instead of a side edge of the end surface 45, can contact the pivot receiving surface 11, specifically, a portion where the tangential plane has the corresponding inclination. The degree of change of the center of rotation of the balance shaft 40 from the central axial line C can therefore be minimized.

In addition, in a state S3 in which the end surface 45F of the pivot 41F on the side where the balance bridge 5 is present is inclined towards the central axial line C of the balance shaft 40 and in the arrangement towards the bottom P2, the inclined end surface 45F comes into contact with the pivot receiving surface 11F of the counter pivot stone 10F, specifically, a portion Cd where the inclination of the pivot receiving the surface 11F of the counter pivot stone 10F in the damping bearing 1F on the side where the rocker bridge 5 is present accepts the inclination of the end surface 45F, as shown in Figs. 6a and 6b. Part Cd substantially coincides with part Cb shown in FIG. 5.

That is to say, in the state S3, the operation of the spring balance 3 differs between the timepiece 2 operating in the upward arrangement P1 and the timepiece 2 operating in the downward arrangement P2, but the difference is the same as that in fig. 5a and 5b, and the difference in the rate of the timepiece between the downward arrangement P2 and the upward arrangement P1 can be considerably smaller than that of the timepiece 102 of the prior art shown in FIG. in figs. 16a and 16b.

The center of rotation Cd of the balance shaft 40 is therefore not on the central axial line C of the balance shaft 40 but is separated from the central axial line C of approximately Ar (which is part of the radius of the pivot 41 and about 10 pm), and the balance shaft 40 rotates with the point Cd being the center of rotation.

As described above, since the receiving surface 11 of the counter pivot stone 10 has a partially spherical shape in the timepiece 2, the amount of change of the center of rotation from the center C of the balance axis 40 is small even when the inclination occurs due to a variety of reasons, where the difference in the rate of the timepiece 2, for example, between the upward arrangement P1 and the disposition to the low P2 can be minimized.

In addition, in the timepiece 2, since the end surfaces 45F and 45R of the pivots 41F and 41R of the balance shaft 40 do not have a partially spherical shape, but the receiving surfaces of pivot 11F and 11R of the counter pivot stone 10 are formed to have a partially spherical shape having a large diameter, the length of the balance shaft 40 and other dimensions thereof are unlikely to vary widely.

Instead of providing the counter-pivot stone with a partially spherical pivot-receiving surface, a counter-pivoting stone 10A may be formed by a sphere 13, as shown in FIGS. 7a and 7b and FIG. 8. In a sprung balance 3A provided with a damping rod receiving structure 1A shown in Figs. 7a and 7b and FIG. 8, the same elements as those of the sprung balance 3 provided with the damper rod receiving structure 1 shown in Figs. 1 to 3 have the same reference numbers, and the elements that correspond to those of the balance spring 3 but differ somewhat from that have a suffix A at the end of the reference numbers. When a reference number is suffixed "F" representing that the element is located on the side where the back of the case or the pendulum bridge is present or a suffix "R" representing that the element is located on the side where the dial is present, a suffix A is added to the reference number before the suffix F or R.

In the damping rod receiving structure 1A for the balance spring 3A, the counter pivot stone 10A is formed of the sphere 13, and therefore the counter pivot stone 10A must probably be cut in a very small manner. precise. In addition, in the damping rod receiving structure 1A for the balance spring 3A, since a timepiece 2A has a large size in the direction of the thickness because the counter-pivoting stone 10A is formed of the Sphere 13, a damping plate 30A is configured in substantially the same manner as the damping plate 30 except that the damping plate 30A has a large diameter tubular portion 32A having an axial length longer than that of the large diameter tubular portion. 32 of the damping base 30.

In addition, in the damping rod receiving structure 1A, since the counter pivot stone 10A is formed of the sphere 13 and the timepiece 2A has a large size in the direction of the thickness, the 10A pivoting stone is supported in the axial direction by a hole 17A instead of a 20A hole stone, in contrast to that of the shock absorbing stem receiving structure 1. A 17dA end surface of the stone Hole 17A therefore has a truncated cone shape to receive a spherical surface 14 of the counter pivot stone 10A. Backstop 10A, specifically, an inner portion of the annular zone of the spherical surface 14 which contacts the truncated cone end surface 17dA, serves as a pivot receiving surface 11A.

A support fastener 37A, specifically, the outer circumferential retaining portions 38a, 38a, 38a, engage with a retaining portion 36 of the cushioning plate 30A, and the U-shaped retainer portions. internal circumferential members 39, 39, 39 push the counter pivoting stone 10A formed of the sphere 13, specifically, an area 12A facing the pivot receiving surface 11A in the radial direction.

[0074] The 20A hole stone kitten is configured substantially in the same manner as the hole stone kit 20 as long as in terms of outer circumferential surface portion and comprises an outer circumferential tubular portion of small diameter 21A corresponding to the small diameter tubular portion 21, a large diameter outer circumferential tubular portion 22A corresponding to the small diameter tubular portion 22, an outer truncated cone shaped bonding collar portion 25A corresponding to the binder collar portion. 25, and the like. Since counter pivot stone 10A, unlike counter pivot stone 10, is formed of sphere 13, which has a small diameter to reduce thickness, counter pivot stone 10A is disposed within a cylindrical inner circumferential surface 27, which is substantially similar to the cylindrical inner circumferential surface 21a of the hole stone kit 20. The cylindrical inner circumferential surface 27 is the inner circumferential surface of the large diameter outer circumferential tubular portion 22A.

In the damping rod receiving structure 1A configured in this way, the pivot 41 of the balance shaft 40 of the balance-spring 3 is installed in a pivot hole 18 in the hole 17A stone and supported by the circumferential surface of the pivot hole 18, which works as a sliding bearing, and the end surface 45 of the pivot 41 enters into

Claims (9)

contact with the pivot receiving surface 11A of the counter pivot stone 10A, which is formed of the sphere 13 and operates as a thrust bearing, and is supported by the pivot receiving surface 11A, as shown in FIG. . 8. [0076] FIG. 9 shows the degree of change in the position of the center of rotation under a variety of conditions in the sprung balance shown in FIG. 8 with the damping bearing shown in FIG. 7. FIG. 9a shows a standard case where the balance shaft and the counter-pivot stone operate in a predetermined state. In this case, the pivot 41 of the balance shaft 40, specifically, a position CO on the end surface 45 of the pivot 41, comes into contact with the pivot receiving surface 11A of the counter-pivoting stone 10A formed of the sphere 13. The position CO corresponds to the position COR in FIG. 4 and is located on the central axial line C of the balance shaft 40. FIG. 9b represents a case where the counter-pivot stone is inclined. Even when the counter-pivoting stone 10A formed of the sphere 13 is slightly inclined (about one degree, for example), the counter-pivoting stone 10A, specifically, the annular zone 14 of the sphere 13, is supported by the surface truncated cone terminal 17dA of the hole stone 17, by a position Cf where the counter-pivoting stone 10A formed of the sphere 13 comes into contact with the end surface 45 of the pivot 41 of the balance shaft 40 does not change not because of the rotation and remains practically in the CO position. Therefore, even when the counter pivot stone 10A is inclined in either upward arrangement P1 or downward arrangement P2, the balance spring 3A can operate in substantially the same manner, and the amount Effect of the disposition on the rate of the timepiece can be minimized. FIG. 9c represents a case where the balance axis is inclined, and the end surface 45 of the pivot 41 is inclined as the balance axis 40 is inclined. In the balance sprocket 3A provided with the damping bearing 1A, however, since the pivoting stone 10A in the damping bearing 1A is formed of the sphere 13 having a relatively small diameter, the inclination of the tangential plane changes considerably when the position of contact is changed from the CO position on the central axial line C only by a small amount. A part which comes into contact with the end surface 45 of the pivot 41 of the slightly inclined rocker axis 40 is therefore slightly separated from the central axial line C, or Cg. Therefore, the effect of the inclination of the balance shaft 40 on the rotation of the balance spring 3A can be minimized. claims A damping bearing for a sprung balance (3; 103; 3A), the damping bearing comprising: a counter pivoting stone (10; 10A; 10F; 10R) which performs the function of a thrust bearing; a hole stone (17; 17A) which performs the function of a plain bearing; a stone kitten with a hole (20; 20A; 20F) which houses the hole stone (17; 17A) and carries the hole stone (17; 17A); a cushioning plate (30; 30A; 30F) which houses the hole stone kitten (20; 20A; 20F) carries the hole stone kitten (20; 20A; 20F) and includes a holding portion (36); side where there is an open end of large diameter; and a support attachment piece (37; 37A; 37F) having an outer rim retained by the retaining portion (36) of the cushioning plate (30; 30A; 30F) and an inner rim resiliently pushing the counter-pivot stone (10; 10A; 10F; 10R) against the hole stone kit (20; 20A; 20F) for holding the counter-pivot stone (10; 10A; 10F; 10R), wherein the surface (11; 11A; 11F; 11R) of the counter pivot stone (10; 10A; 10F; 10R) which is arranged to oppose an end surface (45; 45F; 45R) of a rod (40) retained by the damping bearing; and contacting said end surface (45; 45F; 45R) of said rod (40) is a convexly curved surface projecting outwardly. A damping bearing according to claim 1, wherein the convex surface (11; 11A; 11F; 11R) of the backstop stone (10; 10A; 10F; 10R) is formed of a spherical surface portion. A damping bearing according to claim 1 or 2, wherein the counter-pivoting stone (10; 10A; 10F; 10R) has a lens-like convex shape, the hole stone kit (20; 20A; 20F) includes a a tubular portion (21) and an enlarged diameter portion (22) on the side where an open end of the tubular portion (21) is located, and the enlarged diameter portion (22) carries the counter-pivoting stone (10; 10A; 10F; 10R), and the outer rim of the support attachment piece (37; 37A; 37F) is retained by the retaining portion (36) of the cushioning plate (30; 30A; 30F) and the inner rim the support attachment piece (37; 37A; 37F) resiliently urges the counter pivoting stone (10; 10A; 10F; 10R) against the enlarged diameter portion of the hole stone kit (20; 20A; 20F); hold the counter pivot stone (10; 10A; 10F; 10R). 4. damping bearing according to claim 1 or 2, wherein the counter pivot stone (10A) is a sphere (13). The damping bearing according to claim 4, wherein the spherical counter-pivoting stone (10A) is arranged in such a manner in a cylindrical area of the stone-to-hole chaton (20A) that the counter-pivot stone (10A) can enter. contact with the hole stone (17A), and the outer edge of the support attachment piece (37A) is retained by the retaining portion (36) of the cushioning plate (30A), and the inner edge of the workpiece mounting bracket (37A) urges counter-pivot stone (10A) against opposing end surface of hole-shaped stone (17A) in cylindrical area of stone-to-hole kit (20A) to elastically urge counter-pivot stone (10A) against the hole stone kitten (20A) through the hole stone (17A) and hold the counter pivot stone (10A). The damping bearing according to one of claims 1 to 5, wherein the portion of the hole stone kitten (20; 20A; 20F) which supports a pivot receiving surface of the counter-pivot stone (10; 10A; 10F; 10R) has a truncated cone shape. 7. Spiral balance comprising a damping bearing according to one of claims 1 to 6. The sprung balance according to claim 7, wherein the rod retained by the damping bearing is a rocker shaft (40), and the end surface (45; 45F; 45R) of a pivot (41; 41F; 41R; ), which is located at each end of the balance shaft (40) and has a diameter smaller than the diameter of a main portion of the balance shaft (40), is substantially a flat surface. 9. Timepiece comprising a damping bearing (3; 103; 3A) according to one of claims 1 to 6 or a sprung balance (3; 103; 3A) according to one of claims 7 and 8.