CN110579953B

CN110579953B - Constant torque mechanism, movement for timepiece and timepiece

Info

Publication number: CN110579953B
Application number: CN201910489403.XA
Authority: CN
Inventors: 森裕一; 藤枝久
Original assignee: Seiko Instruments Inc
Current assignee: Seiko Instruments Inc
Priority date: 2018-06-07
Filing date: 2019-06-06
Publication date: 2022-04-01
Anticipated expiration: 2039-06-06
Also published as: CH715052B1; CN110579953A; JP2019211404A; JP6566432B1; CH715052A2

Abstract

The invention provides a constant torque mechanism, a timepiece movement, and a timepiece, which can suppress variation in torque transmitted to an escapement. The constant torque mechanism is provided with: a planet carrier which rotates about a first axis of rotation by means of power from a barrel wheel; a planetary gear supported by the carrier so as to be rotatable; a constant force spring (100) to which power is supplemented by rotation of the carrier; a constant force lower wheel which rotates by the power from the constant force spring and transmits the power of the constant force spring to the escapement; a base (95) of the lever spring rotating in a clockwise direction about a first axis of rotation in synchronism with rotation of the constant force lower pulley; and an engagement shoe that rotates clockwise around the first rotation axis in accordance with rotation of the base and is capable of engaging with and disengaging from the planetary gear, and that is capable of being displaced relative to the base and retreating from a rotation locus of the planetary gear after being engaged with the planetary gear within the rotation locus of the planetary gear and rotation of the planetary gear is restricted.

Description

Constant torque mechanism, movement for timepiece and timepiece

Technical Field

The invention relates to a constant torque mechanism, a timepiece movement, and a timepiece.

Background

In general, in a mechanical timepiece, if the torque (power) transmitted from a barrel wheel to an escapement fluctuates in accordance with unwinding of a spring, the swing angle of a balance-spring mechanism changes in accordance with the fluctuation of the torque, and the rate of change (the slowness of the timepiece) of the timepiece changes. Therefore, in order to suppress the fluctuation of the torque transmitted to the escapement, a known means is to provide a constant torque mechanism on a power transmission path from the barrel wheel to the escapement.

As such a constant torque mechanism, various types of mechanisms have been proposed, and for example, when focusing on cycle control, the mechanism is roughly classified into three types, namely, a cam type, a gear train type, and a planetary gear type.

The cam type constant torque mechanism includes, for example, a follower or a fork which engages with a cam connected to the escapement side train and swings in accordance with rotation of the cam, and an engagement/disengagement period is controlled by periodically engaging and disengaging an engagement/disengagement pawl provided on the follower or the fork with and from an escapement wheel connected to the power source side train. Thus, the constant-torque spring between the power source side train wheel and the escapement side train wheel can be wound up.

In the constant torque mechanism of the gear train system, the power source side gear train and the escapement side gear train are connected by a differential mechanism, and the engagement/disengagement pawl that is disengaged from the detent wheel is moved into and out of the track of the detent wheel, whereby the phase difference can be controlled periodically.

As described in patent documents 1 and 2, for example, the planetary gear type constant torque mechanism includes a planetary mechanism having a detent wheel as a planetary gear, and can periodically control a phase difference between a power source side train and an escape side train by the planetary mechanism. The planetary gear revolves while rotating so as to follow an engagement/disengagement pawl provided on a sun gear connected to an escape machine side train, and the planetary gear periodically engages with and disengages from the engagement/disengagement pawl.

Patent document 1: swiss national patent application publication No. 296060

Patent document 2: swiss national patent application publication No. 707938

In the planetary constant torque mechanism, the direction of the force acting between the planetary gear and the engaging/disengaging pawl in a state where the tooth tip of the planetary gear is in contact with the engaging/disengaging pawl is along the normal direction of the contact portion between the planetary gear and the engaging/disengaging pawl. Therefore, immediately before the planetary gear is disengaged from the engaging/disengaging pawl, the direction of the force acting between the planetary gear and the engaging/disengaging pawl approaches the rotational direction of the engaging/disengaging pawl while the tooth tip of the planetary gear is in contact with the corner of the engaging/disengaging pawl. As a result, the torque transmitted from the sun gear provided with the engagement/disengagement pawl to the escapement increases, and the pivot angle of the balance spring mechanism changes.

Disclosure of Invention

Therefore, the present invention provides a constant torque mechanism, a timepiece movement, and a timepiece in which fluctuation of torque transmitted to an escapement is suppressed.

The constant torque mechanism of the present invention is characterized by comprising: a planetary carrier that rotates about a first axis by power from a power source; a planetary gear rotatably supported by the carrier, the planetary gear rotating about a second axis and revolving about the first axis; a constant force spring that is supplemented with power by rotation of the carrier; a constant force wheel that rotates by power from the constant force spring and transmits the power of the constant force spring to an escapement; a synchronous rotation portion that rotates in a first direction about the first axis in synchronization with rotation of the constant force wheel; and an engagement claw that rotates in the first direction in accordance with rotation of the synchronous rotating portion and is capable of engaging with and disengaging from the planetary gear, wherein when the engagement claw engages with the planetary gear within a rotation locus of the planetary gear to restrict rotation of the planetary gear, the engagement claw is displaced with respect to the synchronous rotating portion and is capable of retracting from the rotation locus.

According to this configuration, the engagement claw is displaced relative to the synchronous rotating portion and retreats from the rotation locus of the planetary gear, whereby the torque in the first direction transmitted from the planetary gear to the synchronous rotating portion via the engagement claw can be reduced immediately before the planetary gear and the engagement claw are disengaged. This can suppress variation in torque transmitted from the synchronous rotating portion to the escapement via the constant force wheel. Therefore, the torque transmitted to the escapement can be suppressed from varying.

In the above-described constant torque mechanism, it is preferable that the engagement claw is displaced in a direction along the first direction with respect to the synchronous rotation portion and retreats from the rotation locus.

According to this configuration, when the direction of the force acting between the planetary gear and the engagement claw is close to the first direction just before the planetary gear and the engagement claw are disengaged, the engagement claw can be pressed by the planetary gear to displace the engagement claw with respect to the synchronous rotating portion. Thus, the torque in the first direction transmitted from the planetary gear to the synchronous rotating portion via the engagement claw is alleviated by the displacement of the engagement claw. Therefore, fluctuation of torque transmitted from the synchronous rotating portion to the escapement via the constant force wheel can be suppressed.

In the above-described constant torque mechanism, it is preferable that the constant torque mechanism further includes a spring portion that directly or indirectly biases the engagement claw toward the inside of the rotation locus.

According to this configuration, it is possible to suppress: the state in which the engagement claw retreats from the rotation locus of the planetary gear is maintained. This stabilizes the engaging and disengaging operation of the engaging pawl with respect to the planetary gear.

In the constant torque mechanism, it is preferable that the constant torque mechanism further includes a lever provided separately from the spring portion, the lever supporting the engagement claw to be rotatable with respect to the synchronous rotation portion.

According to this configuration, the engaging pawl can be stably supported as compared with a case where the engaging pawl is supported by the spring portion. This makes it possible to stabilize the displacement of the engagement claw with respect to the synchronous rotating portion, and to stabilize the engagement and disengagement operation of the engagement claw with respect to the planetary gear.

In the constant torque mechanism, it is preferable that the engagement claw is supported by the spring portion.

According to this configuration, the number of components can be reduced as compared with a configuration in which the engagement claw is not supported by the spring portion.

In the constant torque mechanism, it is preferable that the synchronous rotating portion includes a first regulating portion that regulates displacement of the engagement pawl engaged with the planetary gear relative to the synchronous rotating portion in a direction along a second direction around the first axis.

According to this configuration, it is possible to suppress: when the engagement claw rotates in a first direction together with the synchronous rotation portion, the engagement claw is displaced in a direction along a second direction opposite to the first direction with respect to the synchronous rotation portion so that the engagement claw cannot be disengaged from the planetary gear. Therefore, the engaging and disengaging operation of the engaging pawl with respect to the planetary gear can be stabilized.

In the constant torque mechanism, it is preferable that the synchronous rotation portion includes a second restriction portion that restricts displacement of the engagement claw retracted from the rotation locus in a direction along the first direction with respect to the synchronous rotation portion.

According to this configuration, it is possible to suppress: after the engagement claw retreats from the rotation locus of the planetary gear, the engagement claw is displaced in the direction along the first direction with respect to the synchronous rotation portion, and the engagement claw cannot enter the rotation locus of the planetary gear again to be engaged. Therefore, the engaging and disengaging operation of the engaging pawl with respect to the planetary gear can be stabilized.

In the constant torque mechanism, it is preferable that the engagement pawl is provided so as to be swingable about the first axis with respect to the synchronous rotating portion.

According to this configuration, as the shaft member that supports the member to which the engaging pawl is attached so as to be displaceable with respect to the synchronous rotation portion, a shaft member that extends along the first axis and supports the synchronous rotation portion can be used. In contrast, when the engagement claw is provided so as to be swingable about an axis different from the first axis with respect to the synchronous rotating portion, it is necessary to provide a separate shaft member disposed on an axis different from the first axis on the synchronous rotating portion as a shaft member for supporting the member to which the engagement claw is attached so as to be displaceable with respect to the synchronous rotating portion. Therefore, the number of components can be reduced as compared with a case where the engaging pawl is provided so as to be swingable about an axis different from the first axis with respect to the synchronous rotating portion.

In the above-described constant torque mechanism, it is preferable that the engagement pawl is provided so as to be swingable about a third axis different from the first axis and the second axis with respect to the synchronous rotation portion.

According to this configuration, since the rotation axis of the engagement claw is arranged on the third axis different from the first axis, the degree of freedom in designing the constant torque mechanism can be improved.

The timepiece movement of the present invention is characterized by including the constant torque mechanism.

A timepiece according to the present invention is characterized by including the timepiece movement described above.

According to this configuration, since the constant torque mechanism is provided which suppresses the variation in torque transmitted to the escapement, a timepiece movement and a timepiece with high accuracy can be realized.

According to the present invention, it is possible to provide a constant torque mechanism, a timepiece movement, and a timepiece in which fluctuation of torque transmitted to an escapement is suppressed.

Drawings

Fig. 1 is an external view of a timepiece illustrating a first embodiment.

Fig. 2 is a block diagram of the movement of the first embodiment.

Fig. 3 is a perspective view of a part of the movement of the first embodiment as viewed from above.

Fig. 4 is a cross-sectional view showing a part of the movement of the first embodiment.

Fig. 5 is a plan view of a part of the movement of the first embodiment as viewed from above.

Fig. 6 is a plan view of the engagement/disengagement lever unit according to the first embodiment as viewed from above.

Fig. 7 is a sectional view showing the engagement and disengagement lever unit of the first embodiment.

Fig. 8 is a perspective view of the planetary gear and the engagement/disengagement lever unit according to the first embodiment as viewed from above.

Fig. 9 is a perspective view of the planetary gear and the engagement/disengagement lever unit according to the first embodiment as viewed from below.

Fig. 10 is a plan view of a part of the constant torque mechanism of the first embodiment as viewed from above.

Fig. 11 is an explanatory diagram of the operation of the constant torque mechanism of the first embodiment.

Fig. 12 is an explanatory view of the operation of the constant torque mechanism of the first embodiment.

Fig. 13 is an explanatory view of the operation of the constant torque mechanism of the first embodiment.

Fig. 14 is an explanatory view of the operation of the constant torque mechanism of the first embodiment.

Fig. 15 is a plan view of the planetary gear and the engagement/disengagement lever unit according to the second embodiment as viewed from above.

Fig. 16 is an explanatory diagram of the operation of the constant torque mechanism of the second embodiment.

Fig. 17 is a plan view of the planetary gear and the engagement/disengagement lever unit according to the third embodiment as viewed from above.

Fig. 18 is an explanatory diagram of the operation of the constant torque mechanism of the third embodiment.

Fig. 19 is a plan view of the planetary gear and the engagement/disengagement lever unit according to the fourth embodiment as viewed from above.

Fig. 20 is an explanatory view of the operation of the constant torque mechanism of the fourth embodiment.

Description of the reference symbols

1: a timepiece; 10: a movement; 11: barrel wheels (power source); 14: an escapement; 30. 130, 230, 330: a constant torque mechanism; 45: a planetary gear; 47: a planet carrier; 60: a constant force lower layer wheel (constant force wheel); 85: a lever main body (lever body); 86: a snap-fit pallet (snap-fit claw); 95: a base (synchronous rotating part); 96: an arm (first restriction section); 97: a spring main body (spring portion); 100: a constant force spring; 194: an angle determination lever (synchronous rotation portion); 195: a fork portion (a first restricting portion, a second restricting portion); 284: a base (synchronous rotating part); 284 b: a protrusion (first restriction portion, second restriction portion); 294: a spring portion; 385: a lever main body (lever body); 395: a base (synchronous rotating part); 397: a spring main body (spring portion); 398: a lever pin (first restriction portion); o1: a first axis of rotation (first axis); o2: a second axis of rotation (second axis); o3: a third axis of rotation (third axis).

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals are given to the same or similar structures having the same or similar functions. In the present embodiment, a mechanical timepiece is described as an example of a timepiece.

[ first embodiment ]

(basic structure of timepiece)

In general, a mechanical body including a drive portion of a timepiece is referred to as a "movement". The state in which the dial and the hands are mounted on the movement and put in the timepiece case to be completed is referred to as "completed product" of the timepiece.

Of the two sides of the bottom plate constituting the base plate of the timepiece, the side on which the glass of the timepiece case is present (i.e., the side on which the dial is present) is referred to as the "back side" of the movement. Further, one of the two sides of the bottom plate on which the case back cover of the timepiece case exists (i.e., the side opposite to the dial) is referred to as a "front side" of the movement.

In the present embodiment, the direction from the dial toward the case back is defined as upward, and the opposite side is defined as downward. Further, a clockwise direction when viewed from above is referred to as a clockwise direction, and a counterclockwise direction when viewed from above is referred to as a counterclockwise direction, with each axis of rotation as a center.

Fig. 1 is an external view of a timepiece illustrating a first embodiment.

As shown in fig. 1, the finished timepiece 1 of the present embodiment includes, in a timepiece case including a case back cover and a glass 2, not shown: a movement (movement for a timepiece) 10; a dial 3 having at least a scale indicating information related to hours; and hands 4 including an hour hand 5, a minute hand 6, and a second hand 7.

Fig. 2 is a block diagram of the movement of the first embodiment.

As shown in fig. 2, the movement 10 includes: barrel wheel 11 as power source; a power source side gear train 12 connected to the barrel wheel 11; an escapement 14 regulated by the governor 13; an escapement side train wheel 15 connected to the escapement 14; and a constant torque mechanism 30 disposed between the power source side train wheel 12 and the escape side train wheel 15.

The constant torque mechanism 30 forms a part of a front side train that generally includes a second wheel, a third wheel, a fourth wheel, and the like. The power source side gear train 12 in the present embodiment is a gear train located closer to the barrel wheel 11 as a power source than the constant torque mechanism 30 as viewed from the constant torque mechanism 30. Similarly, the escapement-side gear train 15 in the present embodiment is a gear train located closer to the escapement 14 than the constant torque mechanism 30 when viewed from the constant torque mechanism 30.

A mainspring 16 is housed inside the barrel wheel 11. The power spring 16 is wound by rotation of an unillustrated arbor coupled to a crown 17 shown in fig. 1. The barrel wheel 11 is rotated by power (torque) associated with unwinding of the mainspring 16, and the power is transmitted to the constant torque mechanism 30 via the power source side gear train 12. In the present embodiment, the case where the power from the barrel wheel 11 is transmitted to the constant torque mechanism 30 via the power source side gear train 12 is described as an example, but the present invention is not limited to this case. For example, the power from the barrel wheel 11 may be directly transmitted to the constant torque mechanism 30 without via the power source side gear train 12.

For example, the power source side gear train 12 has a first transmission wheel 18. The first transfer wheel 18 is, for example, a third wheel. The first transmission wheel 18 is pivotally supported between a base plate 23 (see fig. 4) and a train wheel support (not shown). The first transfer wheel 18 rotates based on the rotation of the barrel wheel 11. When the first transmission wheel 18 rotates, a minute wheel not shown rotates based on the rotation. The minute hand 6 shown in fig. 1 is mounted on the minute wheel, and the minute hand 6 displays "minutes" by the rotation of the minute wheel. The minute hand 6 rotates at a rotational speed regulated by the escapement 14 and the speed regulator 13, that is, 1 hour and 1 turn.

When the first transmission wheel 18 rotates, the not-shown straddle wheel rotates based on the rotation, and further, the not-shown hour wheel rotates based on the rotation of the straddle wheel. An hour hand 5 shown in fig. 1 is attached to the hour wheel, and the hour hand 5 displays "hour" by rotation of the hour wheel. The hour hand 5 rotates at a rotation speed regulated by the escapement 14 and the speed regulator 13, for example, 1 turn for 12 hours.

The escape machine side train wheel 15 mainly includes a second transmission wheel 19. The second transfer wheel 19 is for example a fourth wheel. The second transmission wheel 19 is pivotally supported between the base plate 23 and the gear train support member, and rotates based on rotation of a constant force lower stage wheel 60 described later of the constant torque mechanism 30. When the second transmission wheel 19 is a fourth wheel, the second hand 7 shown in fig. 1 is attached to the second transmission wheel 19, and the second hand 7 displays "seconds" based on the rotation of the second transmission wheel 19. The second hand 7 rotates at a rotational speed regulated by the escapement 14 and the speed regulator 13, for example, 1 turn for 1 minute.

The escapement 14 mainly includes an escape wheel and an escape fork (both not shown).

The escape wheel is pivotally supported between the bottom plate 23 and the train wheel support, for example, in mesh with the second transmission wheel 19. Thus, power from a constant force spring 100, which will be described later, in the constant torque mechanism 30 is transmitted to the escape wheel via the escape side train 15. Thereby, the escape wheel rotates by the power from the constant force spring 100.

The pallet is supported to be rotatable (swingable) between the bottom plate 23 and a pallet bridge (not shown), and has a pair of pallet stones (not shown). The pair of pallet stones are alternately engaged with and disengaged from the escapement tooth on the escape wheel at a predetermined cycle by the speed controller 13. This enables the escape wheel to escape at a predetermined cycle.

The governor 13 mainly includes a balance spring mechanism (not shown).

The balance spring mechanism includes a balance staff, a balance, and a balance spring, and is pivotally supported between the bottom plate 23 and a balance bridge (not shown). The balance spring mechanism rotates reciprocally (rotates forward and backward) at a constant swing angle using a balance spring as a power source.

(constant Torque mechanism structure)

The constant torque mechanism 30 is a mechanism that suppresses a variation in power (torque variation) transmitted to the escapement 14.

As shown in fig. 3, the constant torque mechanism 30 includes: a fixed gear 31 having a first rotation axis O1 extending up and down as a center axis; a constant force upper sheave 40 that rotates about a first rotation axis O1; a constant-force lower sheave 60 (constant-force sheave) that is disposed coaxially with the constant-force upper sheave 40 and is rotatable relative to the constant-force upper sheave 40 about a first rotation axis O1; a snap-fit disengagement lever unit 80 that connects the constant-force upper-stage wheel 40 and the constant-force lower-stage wheel 60; a constant force spring 100 for transmitting the accumulated power to the constant force upper stage wheel 40 and the constant force lower stage wheel 60; and a torque adjustment mechanism 110 that adjusts the torque of the constant force spring 100. The first rotation axis O1 is arranged at a position offset in the in-plane direction of the base plate 23 (see fig. 4) with respect to the rotation axes of the first transmission pulley 18 and the second transmission pulley 19 (see fig. 2).

As shown in fig. 4, the fixed gear 31 is disposed between the bottom plate 23 and the constant force unit clamping plate 24. The constant force unit clamp plate 24 is disposed above the bottom plate 23. The fixed gear 31 includes a cylindrical body 32 disposed coaxially with the first rotation axis O1, and a gear main body 33 formed integrally with the cylindrical body 32.

The cylinder 32 is fixed to the lower surface of the constant force unit clamp plate 24 by a fixed gear pin 34 projecting downward from the constant force unit clamp plate 24. The cylinder 32 has a center hole 35 and a window 36. The center hole 35 extends vertically with a constant inner diameter centering on the first rotation axis O1, and vertically penetrates the cylinder 32. The window portion 36 is adjacent to the center hole 35 in a direction in which the first rotation axis O1 is aligned with the rotation axis of the first transfer pulley 18 when viewed in the vertical direction (see fig. 3). The window 36 extends through the cylinder 32 in the vertical direction and is connected to the center hole 35. Thus, the hole penetrating the fixed gear 31 in the up-down direction is a long hole when viewed in the up-down direction.

The gear main body 33 is formed coaxially with the first rotation axis O1 and protrudes radially outward from the lower end portion of the cylinder 32. On the outer peripheral surface of the gear main body 33, fixed teeth 33a are formed over the entire circumference. That is, the fixed gear 31 is an external gear type gear.

The constant force upper wheel 40 is pivotally supported between the base plate 23 and the constant force unit clamp plate 24. The constant-force upper tier wheel 40 has: a rotary shaft 41 that rotates about a first rotation axis O1; a planetary wheel 43 that revolves around the first rotation axis O1; and a carrier 47 that axially supports the planetary gear 43.

The rotary shaft 41 extends along the first rotation axis O1. The rotary shaft 41 is supported by the bottom plate 23 and the constant force unit clamp plate 24 via through-

hole jewel bearings

25A and 25B. The through

hole jewel bearings

25A and 25B are formed of artificial jewels such as ruby. The through

hole jewel bearings

25A and 25B are not limited to those formed of artificial jewels, and may be formed of other brittle materials or metal materials such as iron-based alloys. A constant force upper pinion 41a is formed on the upper portion of the rotary shaft 41. The constant force upper pinion 41a meshes with the first transfer wheel 18. Thereby, power from the barrel wheel 11 (both refer to fig. 2) is transmitted to the rotary shaft 41 via the power source side gear train 12. The power of torque Tb is transmitted from barrel wheel 11 to rotary shaft 41. Hereinafter, the torque Tb is referred to as torque Tb of the barrel 11. The rotation shaft 41 is rotated in the clockwise direction by the power from the barrel wheel 11.

Here, a concave portion 27 that is concave in a direction from the rotation axis of the first transmission wheel 18 toward the first rotation axis O1 is formed in at least one of the constant force unit bridge 24 and the cylinder 32. In the present embodiment, the concave portion 27 is formed to straddle both the constant force unit clamp plate 24 and the cylindrical body 32. The recess 27 opens towards the axis of rotation of the first transfer wheel 18. A part of the constant-force upper pinion 41a is disposed inside the recess 27. Thus, even when the constant force unit bridge 24 and the rotary shaft 41 are arranged at predetermined positions during assembly of the movement 10, the first transmission wheel 18 can be inserted so as to slide into the recess 27 and coupled to the constant force upper pinion 41 a.

The carrier 47 is fixedly supported by the rotary shaft 41. The clockwise torque Tb from the rotary shaft 41 is transmitted to the carrier 47. Thereby, the carrier 47 rotates clockwise about the first rotation axis O1 together with the rotation shaft 41 by the power from the barrel wheel 11. The carrier 47 includes: a lower seat 48 integrally connected to the rotary shaft 41; and an upper seat 54 disposed above the lower seat 48 and fixed to the lower seat 48.

The lower seat 48 is disposed below the fixed gear 31. The lower seat 48 includes: a planet wheel support portion 49 that supports the planet wheels 43; a spring support portion 50 that supports the constant force spring 100; and a coupling portion 51 that couples the planet wheel supporting portion 49 and the spring supporting portion 50.

As shown in fig. 3 and 5, the planet wheel supporting portion 49 extends in an arc shape in the circumferential direction around the first rotation axis O1 when viewed in the vertical direction. The planet wheel support portion 49 is formed such that: the middle portion is lowered one step below the both end portions when viewed in the vertical direction.

As shown in fig. 4, the spring support portion 50 is provided on the opposite side of the planet wheel support portion 49 with the first rotation axis O1 interposed therebetween. The spring support portion 50 is formed with a pin insertion hole 50a through which a constant force spring pin 103 to be described later is inserted. A center hole through which rotating shaft 41 is inserted is formed in coupling portion 51. The connection portion 51 is fixed to the lower portion of the rotation shaft 41 below the constant force upper pinion 41 a. Thereby, the lower seat 48 rotates integrally with the rotary shaft 41. A carrier window portion 52 is formed in the lower seat 48. The carrier window portion 52 is formed on the first rotation axis O1 side with respect to the planet wheel supporting portion 49. The carrier window 52 vertically penetrates the lower seat 48. The carrier window portion 52 prevents the lower seat 48 from coming into contact with an engagement pallet 86 (engagement claw) described later.

As shown in fig. 3, the upper seat 54 is disposed above the planetary wheel support portion 49 of the lower seat 48 and above the gear main body 33 of the fixed gear 31. The upper seat 54 extends in an arc shape in the circumferential direction around the first rotation axis O1 when viewed in the vertical direction. The upper seat 54 is stacked with a plurality of washers 55 in a spaced state with respect to the planetary wheel support portion 49 of the lower seat 48. Both end portions of the upper seat 54 are fixed to both end portions of the planet wheel supporting portion 49 by a plurality of bolts 56 inserted through a plurality of washers 55.

As shown in fig. 4, planetary gear 43 is supported by carrier 47 so as to be rotatable. Specifically, the planetary gear 43 is supported by the planetary gear support portion 49 of the lower carrier 48 and the upper carrier 54 via the through-

hole jewel bearings

59A and 59B, and is rotatable about the second rotation axis O2. The second rotation axis O2 is disposed at a position offset in the in-plane direction of the bottom plate 23 with respect to the first rotation axis O1, and is also disposed at a position fixed to the carrier 47. The planetary gear 43 is disposed between an intermediate portion of the planetary gear support portion 49 of the lower seat 48 as viewed in the vertical direction and an intermediate portion of the upper seat 54 as viewed in the vertical direction (see fig. 3). The planetary gear 43 includes a planetary pinion 44 and a planetary gear 45.

The planetary pinion 44 meshes with the fixed teeth 33a of the fixed gear 31. Since the fixed gear 31 is of the external-tooth type, the pinion 43 revolves around the first rotation axis O1 in the clockwise direction while rotating around the second rotation axis O2 in the clockwise direction in accordance with the clockwise rotation of the carrier 47 by the meshing of the pinion 44 with the fixed gear 31.

The planetary gear 45 is formed below the planetary pinion gear 44 and can rotate (rotate and revolve) without contacting the fixed gear 31. The planetary gear 45 has a plurality of stopper teeth 45a that can engage with and disengage from an engagement surface 86a (see fig. 8) of an engagement yoke 86, which will be described later. The number of the stop teeth 45a is 8 teeth. However, the number of teeth is not limited to this case, and may be appropriately changed.

As shown in fig. 5, the stopper tooth 45a extends in the clockwise direction about the second rotation axis O2 as viewed from the up-down direction as being away from the second rotation axis O2. The tip of the stopper tooth 45a is an action surface that engages with and disengages from the engagement surface 86a of the engagement yoke shoe 86. The tip of the stopper tooth 45a is formed in a convex curved surface shape when viewed from the up-down direction. Hereinafter, a rotation locus M drawn by the tooth tip of the stopper tooth 45a along with the rotation of the planetary gear 43 is referred to as a rotation locus M of the planetary gear 45.

As shown in fig. 4, the constant-force lower sheave 60 is rotatably supported by the rotating shaft 41 of the constant-force upper sheave 40 between the bottom plate 23 and the constant-force unit clamp plate 24. The constant force lower stage wheel 60 is disposed below the carrier 47 of the constant force upper stage wheel 40, and is disposed between the carrier 47 and the bottom plate 23. The constant force lower wheel 60 includes: a constant force lower cylinder 61 inserted into the rotary shaft 41; and a constant force lower gear 62 integrally connected to the constant force lower cylinder 61. In addition, the constant force lower sheave 60 rotates in the clockwise direction about the first rotation axis O1 by the power transmitted from the constant force spring 100.

The rotary shaft 41 is inserted into the constant force lower stage cylinder 61 from above and projects below the constant force lower stage cylinder 61. Annular through-

hole jewel bearings

69A and 69B are pressed into the inner sides of the upper and lower ends of the constant-force lower cylinder 61. The rotary shaft 41 is inserted through the through-

hole jewel bearings

69A and 69B.

The constant force lower gear 62 is integrally connected to the lower end of the constant force lower cylinder 61. A constant force lower gear 62a meshing with the second transmission wheel 19 is formed on the outer peripheral surface of the constant force lower gear 62 over the entire periphery. Thus, the constant force lower wheel 60 can transmit the power from the constant force spring 100 to the second transmission wheel 19 connected to the escapement 14, that is, the escapement side train wheel 15.

In the present embodiment, the case where the power from the constant force spring 100 is transmitted to the escapement 14 via the escapement side gear train 15 is described as an example, but the present invention is not limited to this case. For example, the power from the constant force spring 100 may be directly transmitted to the escapement 14 without providing the escapement side train 15.

The engagement/disengagement lever unit 80 includes an engagement yoke 86 that engages with and disengages from the stopper teeth 45a of the planetary gear 45, and supports the engagement yoke 86 so as to be rotatable about the first rotation axis O1. The engagement/disengagement lever unit 80 includes: a rod bushing 81 and a rod spring 94 provided so as not to relatively rotate with respect to the constant-force lower stage cylinder 61; and an engaging/disengaging lever 84 provided to be rotatable relative to the constant-force lower cylinder 61.

The rod bushing 81 is formed in a cylindrical shape coaxial with the first rotation axis O1. The rod bushing 81 is inserted around the upper end of the constant force lower drum 61 of the constant force lower wheel 60 and is integrally connected to the constant force lower drum 61. Thereby, the lever bushing 81 rotates in the clockwise direction about the first rotation axis O1 in synchronization with the rotation of the constant-force lower stage wheel 60. A flange 82 protruding radially outward is formed at the upper end portion of the rod bushing 81.

Fig. 6 is a plan view of the engagement/disengagement lever unit according to the first embodiment as viewed from above. Fig. 7 is a sectional view showing the engagement and disengagement lever unit of the first embodiment.

As shown in fig. 6 and 7, the engagement and disengagement lever 84 is provided so as to be rotatable relative to the lever bushing 81 and the lever spring 94 about the first rotation axis O1. The engagement/disengagement lever 84 includes: a lever main body 85 (lever body); and an engaging pallet 86 and a lever pin 87 supported by the lever main body 85.

The lever main body 85 is disposed below the planetary gear 45 of the planetary gear 43 (see fig. 4). The lever main body 85 is rotatably supported by the upper and lower intermediate portions of the lever bushing 81. The lever main body 85 is restricted from moving upward relative to the constant-force lower stage cylinder 61 by the flange 82 of the lever bushing 81. The rod main body 85 includes a first rod piece 90, a second rod piece 91, and a third rod piece 92 extending radially outward from the rod bushing 81 side. The first lever piece 90, the second lever piece 91, and the third lever piece 92 are arranged at intervals in the circumferential direction around the first rotation axis O1. In the illustrated example, through holes penetrating vertically are formed in the base end portions of the first lever piece 90, the second lever piece 91, and the third lever piece 92. However, the shapes of the first lever piece 90, the second lever piece 91, and the third lever piece 92 are not limited to this case, and may be freely changed. The shape of the lever main body 85 is not limited to the above shape, and can be freely changed. For example, the lever main body may not include the third lever piece 92.

A pallet holding portion 90a for holding the engagement pallet 86 is formed at the distal end portion of the first lever piece 90. The pallet stone holding portion 90a penetrates the first lever piece 90 vertically. A pin holding portion 91a for holding the lever pin 87 is formed at the distal end portion of the second lever piece 91. The pin holding portion 91a vertically penetrates the second lever piece 91.

Fig. 8 is a perspective view of the planetary gear and the engagement/disengagement lever unit according to the first embodiment as viewed from above. Fig. 9 is a perspective view of the planetary gear and the engagement/disengagement lever unit according to the first embodiment as viewed from below.

As shown in fig. 8 and 9, the engagement pallet 86 is attached to the pallet holding portion 90a of the first lever piece 90, and is supported by the lever main body 85 so as to be rotatable with respect to the lever bushing 81 and the lever spring 94. Thereby, the engagement pallet 86 is provided swingably about the first rotation axis O1. The engaging pallet 86 is formed of an artificial gem such as ruby. The engagement pallet 86 is not limited to being formed of an artificial stone as in the case of the above-described through-hole stone bearing, and may be formed of another brittle material or a metal material such as an iron-based alloy, for example. The engagement shoe 86 may be formed integrally with the lever main body 85 instead of being separate from the lever main body 85. The engagement shoe 86 is held in a state of protruding to a position closer to (above) the planetary gear 45 than the shoe holding portion 90 a. The engagement pallet 86 is disposed inside the carrier window 52 of the carrier 47 of the constant force upper stage wheel 40 (see fig. 4).

As shown in fig. 8 and 10, a side surface of the protruding portion of the engagement yoke shoe 86 on the opposite side to the first rotation axis O1 is an engagement surface 86a on which the tooth tip of the stopper tooth 45a of the planetary gear 45 can be engaged and disengaged. In the illustrated example, the engaging surface 86a is substantially entirely flat, and has both end portions R-chamfered when viewed in the vertical direction. That is, the engagement surface 86a is formed in a convex curved surface shape at the end edges on both sides in the circumferential direction around the first rotation axis O1 when viewed in the vertical direction. Hereinafter, an end edge of the engaging surface 86a in the counterclockwise direction around the first rotation axis O1 is referred to as a first end edge 86a 1. The engagement yoke 86 engages with the planetary gear 45 within the rotation locus M of the planetary gear 45 to restrict the rotation of the planetary gear 43. The engagement yoke 86 is displaced in the clockwise direction about the first rotation axis O1 with respect to the planetary gear 43, retreats from the rotation locus M of the planetary gear 45, and thereby disengages from the stopper tooth 45a and releases the engagement with the planetary gear 45.

As shown in fig. 7, the lever pin 87 includes: a shaft body 87a formed in a vertically extending cylindrical shape and inserted through the pin holding portion 91a of the lever main body 85; and a head 87b having a diameter enlarged at a lower end of the shaft body 87 a. The shaft body 87a protrudes from the second lever piece 91 to both upper and lower sides. The head 87b is disposed at a distance from the lower surface of the second rod piece 91.

As shown in fig. 7 and 9, the rod spring 94 is disposed below the rod main body 85 and is fixedly supported by the lower end portion of the rod bushing 81. Thereby, the lever spring 94 rotates in the clockwise direction about the first rotation axis O1 in synchronization with the rotation of the constant-force lower stage wheel 60. The lever spring 94 includes a base portion 95 (synchronous rotation portion) fixed to the lever bushing 81 and a spring main body 97 (spring portion) extending from the base portion 95.

As shown in fig. 9, the base 95 is formed in a ring shape surrounding the first rotation axis O1. The base 95 is inserted externally to the lower end of the rod bushing 81 and is integrally connected to the rod bushing 81. The base 95 can abut against the lever main body 85 of the engagement/disengagement lever 84 from below, and restricts downward movement of the lever main body 85 relative to the lever bushing 81. An arm 96 is formed on the base 95.

As shown in fig. 6, the arm 96 extends in a direction in which the second lever piece 91 of the engagement/disengagement lever 84 extends when viewed in the vertical direction. The distal end portion of the arm 96 abuts against the shaft body 87a of the lever pin 87 in the counterclockwise direction about the first rotation axis O1 between the distal end portion of the second lever piece 91 and the head 87b of the lever pin 87 (see also fig. 9). Thus, the arm 96 restricts the rotation of the engagement/disengagement lever 84 counterclockwise about the first rotation axis O1 with respect to the base 95. That is, the arm 96 restricts the counterclockwise displacement of the engagement yoke 86 (both refer to fig. 8) engaged with the planetary gear 45 with respect to the base 95 about the first rotation axis O1. The lever spring 94 presses the engagement release lever 84 in the clockwise direction about the first rotation axis O1 to rotate it.

The spring body 97 is a thin plate spring. The spring body 97 extends from the tip end portion of the arm 96 in the counterclockwise direction about the first rotation axis O1. The spring body 97 radially outwardly surrounds the base 95 and contacts the shaft body 87a of the lever pin 87 in the clockwise direction about the first rotation axis O1 between the distal end portion of the second lever piece 91 and the head 87b of the lever pin 87 (see also fig. 9). Thereby, the spring main body 97 biases the engagement and disengagement lever 84 in the counterclockwise direction about the first rotation axis O1 with respect to the base 95, and allows the engagement and disengagement lever 84 to be displaced in the clockwise direction about the first rotation axis O1 with respect to the base 95. As described above, the engagement yoke 86 included in the engagement/disengagement lever 84 has a clockwise play about the first rotation axis O1 with respect to the base 95.

As shown in fig. 10, the constant force spring 100 is a sheet spring made of metal such as iron or nickel or an alloy, and is formed in a spiral shape. Specifically, the constant force spring 100 is formed in a spiral shape along an archimedean curve in a polar coordinate system with the first rotation axis O1 as an origin. Thus, the constant force spring 100 is wound in a plurality of windings so as to be adjacent to each other at substantially equal intervals in the radial direction when viewed in the vertical direction.

As shown in fig. 4, the constant force spring 100 is disposed below the engagement/disengagement lever unit 80 and between the engagement/disengagement lever unit 80 and the constant force lower gear 62. One circumferential end portion, i.e., an outer end portion 101, of the constant force spring 100 is connected to the lower seat 48 of the carrier 47 of the constant force upper stage wheel 40 via a constant force spring pin 103, and the other circumferential end portion, i.e., an inner end portion 102, is connected to the constant force lower stage wheel 60 via a fixed ring 104 and a torque adjusting mechanism 110. Thus, the constant force spring 100 can transmit the accumulated power to the constant force upper stage wheel 40 and the constant force lower stage wheel 60, respectively.

The constant force spring pin 103 is held by the spring support portion 50 in a state of protruding below a pin insertion hole 50a formed in the spring support portion 50 of the constant force upper sheave 40. An outer end 101 of the constant force spring 100 is fixed to a projecting portion of the constant force spring pin 103.

A retaining ring 104 is secured to the inner end 102 of the constant force spring 100. The fixing ring 104 is formed in an annular shape coaxial with the first rotation axis O1. The fixed ring 104 is integrally coupled to a constant force spring bushing 111 of the torque adjustment mechanism 110, which will be described later.

The constant force spring 100 is wound in a clockwise direction by a predetermined winding amount toward the outer end 101 with the inner end 102 as an unwinding position. The constant force spring 100 is elastically deformed so as to be reduced in diameter by being wound up, and is preloaded. Therefore, power of the torque Tc is generated in the constant force spring 100, and the power is accumulated. The power accumulated in the constant force spring 100 is transmitted to the constant force upper sheave 40 and the constant force lower sheave 60 along with the elastic recovery deformation of the constant force spring 100. Thereby, the constant-force upper stage wheel 40 and the constant-force lower stage wheel 60 can be rotated in opposite directions to each other about the first rotation axis O1 by the power transmitted from the constant-force spring 100. Specifically, the constant force lower tier wheel 60 is able to rotate in a clockwise direction and the constant force upper tier wheel 40 is able to rotate in a counterclockwise direction. Hereinafter, the torque Tc is referred to as a torque Tc of the constant force spring 100. When the power spring 16 in the barrel wheel 11 is wound by a predetermined winding amount, the torque Tc is smaller than the torque Tb of the rotating shaft 41.

The torque adjusting mechanism 110 applies a preload to the constant force spring 100 to adjust the torque Tc of the constant force spring 100. The torque adjustment mechanism 110 includes: a constant force spring bushing 111 supported by the constant force lower cylinder 61 of the constant force lower wheel 60; a first torque adjustment gear 112 integrally coupled with the constant force spring bushing 111; a second torque adjustment gear 113 integrally connected to the constant force lower cylinder 61; and a torque adjusting crossover 114 connecting the first torque adjusting gear 112 and the second torque adjusting gear 113.

The constant force spring bushing 111 is formed in a cylindrical shape coaxial with the first rotation axis O1. The constant force spring bushing 111 is externally inserted into the constant force lower barrel 61 between the constant force lower gear 62 and the engagement and disengagement lever unit 80. The constant force spring bushing 111 is provided to be rotatable about the first rotation axis O1 with respect to the constant force lower stage cylinder 61. The above-described fixed ring 104 is inserted around the upper and lower intermediate portions of the constant force spring bushing 111, and the constant force spring bushing 111 and the fixed ring 104 are integrally connected.

The first torque adjustment gear 112 is integrally coupled to a lower end portion of the constant force spring bushing 111. On the outer peripheral surface of the first torque adjustment gear 112, first torque adjustment teeth 112a are formed over the entire circumference. The first torque adjustment teeth 112a mesh with a gear for torque adjustment, not shown.

The second torque adjustment gear 113 is disposed between the constant force lower gear 62, the constant force spring bushing 111, and the first torque adjustment gear 112. The second torque adjustment gear 113 is integrally connected to the constant force lower cylinder 61. The second torque adjustment gear 113 is formed to be smaller in diameter than the first torque adjustment gear 112. Second torque adjustment teeth 113a are formed on the outer peripheral surface of the second torque adjustment gear 113 over the entire peripheral range. The torque adjustment crossover 114 releasably engages the second torque adjustment teeth 113 a.

The torque adjustment crossover 114 is supported by the first torque adjustment gear 112 and is capable of revolving around the second torque adjustment gear 113 about the first rotation axis O1. The torque adjusting crossover 114 can limit the rotation of the first torque adjusting gear 112 relative to the second torque adjusting gear 113 in the clockwise direction. Further, the torque adjusting crossover 114 can allow the first torque adjusting gear 112 to rotate in a counterclockwise direction relative to the second torque adjusting gear 113.

Thus, when the constant force spring bushing 111 and the first torque adjusting gear 112 receive clockwise power from the constant force spring 100, the power is transmitted to the second torque adjusting gear 113 via the torque adjusting crossover 114. In this way, the torque adjusting crossover 114 restricts the clockwise rotation of the first torque adjusting gear 112 with respect to the second torque adjusting gear 113, and the first torque adjusting gear 112 and the second torque adjusting gear 113 integrally rotate in the clockwise direction. As a result, the constant force lower sheave 60 also rotates clockwise together with the second torque adjustment gear 113.

When a preload is applied to the constant force spring 100, a gear for torque adjustment, not shown, is engaged with the first torque adjustment gear 112 and is rotated, whereby the first torque adjustment gear 112 is rotated counterclockwise. In this way, the torque adjustment crossover 114 allows counterclockwise rotation of the first torque adjustment gear 112 relative to the second torque adjustment gear 113, and therefore, the constant force spring bushing 111 and the fixed ring 104 are rotated in a counterclockwise direction without rotating the constant force lower pulley 60. Thereby, the inner end portion 102 of the constant force spring 100 can be rotated in the counterclockwise direction. As a result, the constant force spring 100 can be wound up, and the preload of the constant force spring 100 can be increased to adjust the torque Tc to be increased.

(action of constant Torque mechanism)

The operation of the constant torque mechanism 30 configured as described above will be described.

In the initial state, the power spring 16 in the barrel drum 11 is wound by a predetermined winding amount, and the power of the torque Tb is transmitted from the barrel drum 11 to the carrier 47 of the constant upper sheave 40 via the power source side gear train 12. The constant force spring 100 is wound by a predetermined amount, and a power of a torque Tc smaller than the torque Tb is transmitted from the constant force spring 100 to the carrier 47 of the constant force upper stage wheel 40 and the constant force lower stage wheel 60.

According to the constant torque mechanism 30 of the present embodiment, since the constant force spring 100 is provided, the power accumulated in the constant force spring 100 can be transmitted to the constant force lower sheave 60, and the constant force lower sheave 60 can be rotated clockwise about the first rotation axis O1. In detail, the power from the constant force spring 100 is transmitted to the torque adjustment mechanism 110 via the fixed ring 104. The power transmitted to the torque adjustment mechanism 110 is transmitted to the constant force lower sheave 60. Thus, the constant force lower sheave 60 is transmitted with the torque Tc from the constant force spring 100 to rotate clockwise about the first rotation axis O1. Further, the power of the constant force spring 100 can be transmitted from the constant force lower pulley 60 to the second transmission pulley 19, and the second transmission pulley 19 can be rotated in accordance with the rotation of the constant force lower pulley 60. That is, the power from the constant force spring 100 can be transmitted to the escape side train wheel 15 via the constant force lower wheel 60, and the escape 14 can be operated.

Further, since the power from the constant force spring 100 is also transmitted to the constant force upper sheave 40, the constant force upper sheave 40 is intended to be rotated in the counterclockwise direction about the first rotation axis O1 by the torque Tc.

However, a torque Tb that rotates in the clockwise direction about the first rotation axis O1 is transmitted from the power source side train 12 to the constant force upper sheave 40. Since the torque Tb is greater than the torque Tc, the constant force upper sheave 40 is prevented from rotating in the counterclockwise direction about the first rotation axis O1.

Further, the constant force upper layer wheel 40 is applied with power (torque Tb — torque Tc) of a difference between the torque Tb transmitted from the power source side gear train 12 and the torque Tc transmitted from the constant force spring 100. However, since the engagement yoke 86 of the engagement/disengagement lever unit 80 engages with the planetary gear 45 within the rotation locus M of the planetary gear 45 of the constant-force upper stage wheel 40, the rotation and revolution of the planetary gear 43 are restricted. This allows the constant force upper stage wheel 40 to be connected to the constant force lower stage wheel 60, and prevents the constant force upper stage wheel 40 from rotating clockwise about the first rotation axis O1.

As described above, the constant force upper wheel 40 is prevented from rotating about the first rotation axis O1 at the stage when the planetary gear 45 engages with the engagement pallet 86. Since the power of the difference is applied to the constant force upper pulley 40, the tip of the stopper tooth 45a of the planetary gear 45 is strongly abutted against the engagement surface 86a of the engagement yoke 86.

Fig. 11 to 14 are operation explanatory views of the constant torque mechanism of the first embodiment, and are plan views of the fixed gear, the planetary gear, and the engagement/disengagement lever unit as viewed from above. In fig. 11 to 14, the fixed gear, the planetary gear, and the engagement/disengagement lever unit are simplified and illustrated.

When the constant-force lower pulley 60 is rotated by the power from the constant-force spring 100, the lever bushing 81 of the engagement release lever unit 80 and the lever spring 94 are rotated clockwise about the first rotation axis O1 along with this. When the lever spring 94 rotates, the click release lever 84 of the click release lever unit 80 is pressed by the arm 96 of the lever spring 94 to rotate in the clockwise direction about the first rotation axis O1. When the engagement/disengagement lever 84 rotates in the clockwise direction, the engagement pallet 86 included in the engagement/disengagement lever 84 is displaced in the clockwise direction about the first rotation axis O1 while having a play in the clockwise direction about the first rotation axis O1. Thereby, the engagement and disengagement lever unit 80 is gradually disengaged from the planetary gear 45 so as to retract the engagement yoke shoe 86 from the rotation locus M of the planetary gear 45. As a result, as shown in fig. 11 to 13, the tip of the stopper tooth 45a moves counterclockwise about the first rotation axis O1 with respect to the engagement surface 86a while sliding on the engagement surface 86a as the engagement pallet 86 is disengaged.

Here, the force F acting between the stopper tooth 45a and the engaging yoke shoe 86 is a resultant force of a pressing force of the stopper tooth 45a pressing the engaging surface 86a and a frictional force generated by the stopper tooth 45a sliding on the engaging surface 86 a. The pressing force is a force parallel to the normal direction of the contact portion between the stopper tooth 45a and the engagement surface 86 a. The frictional force is a force parallel to the tangential direction of the contact portion between the stopper tooth 45a and the engagement surface 86 a. Since the tip of the stopper tooth 45a and the first end edge 86a1 of the engagement surface 86a are formed in the shape of a convexly curved surface when viewed in the vertical direction, the force F approaches the clockwise direction around the first rotation axis O1 (see fig. 13) when the tip of the stopper tooth 45a contacts the first end edge 86a1 of the engagement surface 86 a. Thus, the engagement/disengagement lever 84 including the engagement yoke shoe 86 rotates clockwise about the first rotation axis O1 with respect to the base 95 against the urging force of the spring main body 97 of the lever spring 94. Then, as shown in fig. 14, the engagement between the stopper tooth 45a and the engagement yoke shoe 86 is released at the point when the tip of the stopper tooth 45a passes over the first end edge 86a1 of the engagement surface 86 a. Thereby, the connection between constant force upper stage wheel 40 and constant force lower stage wheel 60 via engagement yoke 86 and planetary gear 43 is released.

Therefore, the constant force upper sheave 40 rotates in the clockwise direction about the first rotation axis O1 by the power of the difference between the torque Tb transmitted from the power source side gear train 12 and the torque Tc transmitted from the constant force spring 100 (torque Tb-torque Tc).

By rotating the constant force upper sheave 40 clockwise about the first rotation axis O1, the constant force spring 100 can be wound up via the constant force spring pin 103 fixed to the carrier 47, and the constant force spring 100 can be supplemented with power. That is, the loss amount of the power lost by the transmission of the power to the constant-force lower sheave 60 can be compensated by the power transmitted from the barrel sheave 11 side as the power source. This can maintain the power of the constant force spring 100 constant, and can operate the escapement 14 with a constant torque.

Even when the constant force spring 100 is supplemented with power, the constant force lower wheel 60 rotates by the power from the constant force spring 100, and the power from the constant force spring 100 is transmitted to the escape side train wheel 15.

In addition, when the power supply to the constant force spring 100 described above is performed, the planetary gear 43 revolves clockwise around the first rotation axis O1 while rotating clockwise around the second rotation axis O2 and follows the engagement pallet 86 as the constant force upper sheave 40 rotates around the first rotation axis O1. The planetary gear 43 rotates by one tooth of the stopper tooth 45a, and then rides over the engagement yoke 86, and the tooth tip of the stopper tooth 45a engages with the engagement surface 86a of the engagement yoke 86 again.

As a result, the constant force upper stage wheel 40 and the constant force lower stage wheel 60 are reconnected, and therefore, the rotation of the constant force upper stage wheel 40 is prevented, and the power supply to the constant force spring 100 is completed.

By repeating the above operations, the planetary gear 45 and the engagement yoke 86 can be intermittently engaged and disengaged. That is, the engagement and disengagement of the planetary gear 45 and the engagement pallet 86 are intermittently performed based on the rotation of the constant force lower pulley 60, and the constant force upper pulley 40 can be intermittently rotated with respect to the constant force lower pulley 60. This allows the constant force spring 100 to be intermittently supplemented with power.

As described above, the constant torque mechanism 30 of the present embodiment includes: a base portion 95 of the lever spring 94 that rotates in the clockwise direction about the first rotation axis O1 in synchronization with the rotation of the constant-force lower pulley 60; and an engagement pallet 86 that rotates clockwise around the first rotation axis O1 in accordance with the rotation of the base 95, is engageable with and disengageable from the planetary gear 45, and is displaceable with respect to the base 95 so as to be able to retreat from the rotation locus M of the planetary gear 45 after being engaged with the planetary gear 45 within the rotation locus M of the planetary gear 45 and restricting the rotation of the planetary gear 45. According to this configuration, by displacing the engagement pallet 86 with respect to the base 95 and retracting from the rotation locus M of the planetary gear 45, the clockwise torque about the first rotation axis O1 transmitted from the planetary gear 45 to the base 95 via the engagement pallet 86 can be reduced immediately before the planetary gear 45 and the engagement pallet 86 disengage. This can suppress variation in torque transmitted from the base 95 to the escapement 14 via the constant-force lower wheel 60. Therefore, variation in torque transmitted to the escapement 14 can be suppressed.

In particular, in the present embodiment, the tip of the stopper tooth 45a of the planetary gear 45 and the first end edge 86a1 of the engagement surface 86a of the engagement yoke shoe 86 are formed in a convex curved surface shape when viewed in the vertical direction. Therefore, as compared with the case where the tooth tips of the stopper teeth of the planetary gear and the first end edges of the engaging surfaces of the engaging shoes are not formed in the convex curved surface shape, the contact surface pressure between the planetary gear 45 and the engaging shoes 86 can be reduced, and the occurrence of the scraping on the planetary gear 45 and the engaging shoes 86 can be suppressed. In this case, the sliding distance between the tooth tip of the stopper tooth 45a of the planetary gear 45 and the first end edge 86a1 of the engaging surface 86a of the engaging yoke shoe 86 is longer than in the case where the tooth tip of the stopper tooth of the planetary gear and the first end edge of the engaging surface of the engaging yoke shoe 86 are not formed in the convex curved surface shape. Therefore, the period in which the direction of the force F acting between the planetary gear 45 and the engagement yoke 86 approaches the clockwise direction around the first rotation axis O1 becomes longer. Here, in the present embodiment, as described above, the engagement yoke 86 is retracted from the rotation locus M of the planetary gear 45 just before the planetary gear 45 and the engagement yoke 86 are disengaged, and the clockwise torque about the first rotation axis O1 transmitted from the planetary gear 45 to the base 95 can be reduced. Therefore, both the improvement of the durability of the constant torque mechanism 30 and the suppression of the torque variation can be achieved.

Further, since the scraping of the planetary gear 45 and the engagement yoke shoe 86 is suppressed, a margin for increasing the force acting on the contact portion of the planetary gear 45 and the engagement yoke shoe 86 is generated. Therefore, the distance between the contact portion of the planetary gear 45 and the engagement yoke 86 and the first rotation axis O1 can be reduced, and the constant torque mechanism 30 can be downsized.

Further, the engagement shoe 86 is displaced in the clockwise direction about the first rotation axis O1 with respect to the base 95 and retreats from the rotation locus M. According to this structure, when the direction of the force F acting between the planetary gear 45 and the engagement pallet 86 approaches the clockwise direction about the first rotation axis O1 just before the planetary gear 45 and the engagement pallet 86 disengage, the engagement pallet 86 can be displaced with respect to the base 95 by the planetary gear 45 pressing the engagement pallet 86. Thereby, the clockwise torque about the first rotation axis O1 transmitted from the planetary gear 45 to the base 95 via the engagement pallet 86 is alleviated by the displacement of the engagement pallet 86. Therefore, the torque transmitted from the base 95 to the escapement 14 via the constant-force lower wheel 60 can be suppressed from varying.

The constant torque mechanism 30 further includes a spring main body 97 that indirectly biases the engagement shoe 86 toward the inside of the rotation locus M via the lever main body 85. According to this configuration, the following can be suppressed: the engagement yoke 86 is maintained in a state retracted from the rotation locus M of the planetary gear 45. This stabilizes the engaging and disengaging operation of the engaging yoke 86 with respect to the planetary gear 45.

The constant torque mechanism 30 further includes a lever main body 85 that supports the engagement yoke shoe 86 so as to be rotatable with respect to the base 95 of the lever spring 94, and the lever main body 85 is provided separately from the spring main body 97. According to this configuration, the engagement shoe 86 can be stably supported, compared to the case where the engagement shoe 86 is supported by a spring portion. This stabilizes the displacement of the engagement yoke 86 with respect to the base 95, and stabilizes the engagement and disengagement operation of the engagement yoke 86 with respect to the planetary gear 45.

Further, the base portion 95 of the lever spring 94 includes an arm 96, and the arm 96 restricts displacement of the engagement fork shoe 86 engaged with the planetary gear 45 with respect to the base portion 95 in the counterclockwise direction about the first rotation axis O1. According to this configuration, it is possible to suppress: when the engagement pallet 86 rotates clockwise about the first rotation axis O1 together with the base 95, the engagement pallet 86 is displaced counterclockwise about the first rotation axis O1 with respect to the base 95, and the engagement pallet 86 cannot be disengaged from the planetary gear 45. Therefore, the engagement and disengagement operation of the engagement yoke 86 with respect to the planetary gear 45 can be stabilized.

Further, the engaging pallet 86 is provided swingably about the first rotation axis O1 with respect to the base 95 of the lever spring 94. According to this configuration, as the shaft member that supports the lever main body 85 to which the engagement shoe 86 is attached so as to be displaceable with respect to the base 95 of the lever spring 94, the lever bushing 81 that extends along the first rotation axis O1 and supports the base 95 can be used. In contrast, when the engagement yoke shoe is provided so as to be swingable about an axis different from the first rotation axis O1, it is necessary to provide a shaft member (for example, the lever rotation shaft 389 of the fourth embodiment shown in fig. 19) which is separately disposed on an axis different from the first rotation axis O1 as a shaft member for supporting the member to which the engagement yoke shoe is attached so as to be swingable. Therefore, the number of components can be reduced compared to a case where the engagement pallet 86 is provided so as to be swingable around an axis different from the first rotation axis O1.

Here, the assembly of the constant torque mechanism 30 will be briefly described. When assembling the constant torque mechanism 30, first, the constant force lower sheave 60 is assembled to the bottom plate 23 together with the torque adjusting mechanism 110, the constant force spring 100, and the engagement/disengagement lever unit 80. Next, the constant force upper stage wheel 40 is assembled to the constant force lower stage drum 61 of the constant force lower stage wheel 60. Next, the fixed gear 31 assembled to the constant force unit clamping plate 24 is assembled to the constant force upper level gear 40. At this time, the gear body 33 of the fixed gear 31 is coupled to the planetary gears 45 of the planetary gears 43 while avoiding the upper seat 54 of the carrier 47, while inserting the rotary shaft 41 into the center hole 35 of the fixed gear 31. Therefore, it is necessary to insert the rotary shaft 41 into the center hole 35 of the fixed gear 31 in a state where the fixed gear 31 is inclined with respect to the first rotation axis O1. In the present embodiment, the center hole 35 of the fixed gear 31 through which the rotary shaft 41 is inserted is connected to the window portion 36, and is formed as a long hole when viewed in the vertical direction. Therefore, the rotary shaft 41 can be inserted into the center hole 35 of the fixed gear 31 in a state where the fixed gear 31 is inclined with respect to the first rotation axis O1. Therefore, the constant torque mechanism 30 with improved assembly workability can be provided.

Furthermore, since the timepiece 1 and the movement 10 according to the present embodiment include the constant torque mechanism 30, and the constant torque mechanism 30 can suppress variation in torque transmitted to the escapement 14 and improve durability, the movement 10 and the timepiece 1 having high accuracy and excellent durability can be realized.

[ second embodiment ]

Next, a second embodiment will be described with reference to fig. 15 and 16. The second embodiment is different from the first embodiment in that the engagement and disengagement lever 84 is not biased. The configuration other than the following description is the same as that of the first embodiment.

(construction of engaging and disengaging lever Unit)

Fig. 15 is a plan view of the planetary gear and the engagement/disengagement lever unit according to the second embodiment as viewed from above. In fig. 15, the planetary gear and the engaging and disengaging lever unit are shown in a simplified manner (the same applies to the following drawings).

As shown in fig. 15, the engagement/disengagement lever unit 180 includes an angle determination lever 194 (synchronous rotation portion) instead of the lever spring 94 of the first embodiment.

The angle determination lever 194 is disposed below the lever main body 85 and is integrally connected to the lower end portion of the lever bushing 81. Thereby, the angle determining lever 194 rotates in the clockwise direction about the first rotation axis O1 in synchronization with the rotation of the constant-force lower stage wheel 60. A bifurcated yoke 195 is formed at one end of the angle determining lever 194. A lever pin 87 is disposed inside the fork 195. The inside of the fork 195 is formed larger than the lever pin 87 in the circumferential direction about the first rotation axis O1. Thus, the fork 195 can rotate the engagement/disengagement lever 84 including the lever pin 87 within a predetermined angular range with respect to the angle determination lever 194.

The fork 195 contacts the lever pin 87 from the counterclockwise direction about the first rotation axis O1 by rotating in the clockwise direction about the first rotation axis O1. Thus, the angle determination lever 194 rotates by pressing the engagement/disengagement lever 84 clockwise about the first rotation axis O1. Further, the fork 195 restricts the rotation of the engagement release lever 84 in the counterclockwise direction about the first rotation axis O1 with respect to the angle determination lever 194. That is, the fork portion 195 restricts the counterclockwise displacement of the engagement fork shoe 86 engaged with the planetary gear 45 with respect to the angle determination lever 194 about the first rotation axis O1. As described above, the engagement yoke 86 included in the engagement/disengagement lever 84 has the play in the clockwise direction about the first rotation axis O1 with respect to the angle determination lever 194.

Further, the fork 195 restricts the rotation of the click release lever 84 in the clockwise direction about the first rotation axis O1 with respect to the angle determination lever 194. That is, the fork portion 195 restricts the displacement of the engagement fork shoe 86 retracted from the rotation locus M of the planetary gear 45 in the clockwise direction about the first rotation axis O1 with respect to the angle determination lever 194.

(function of engaging and disengaging lever unit)

The operation of the engagement and disengagement lever unit 180 configured as described above will be described.

As in the first embodiment, at the stage when the planetary gear 45 is engaged with the engagement yoke 86, the tip of the stopper tooth 45a of the planetary gear 45 is strongly abutted against the engagement surface 86a of the engagement yoke 86.

When the constant-force lower pulley 60 is rotated by the power from the constant-force spring 100, the lever bushing 81 and the angle determination lever 194 of the engagement/disengagement lever unit 180 are rotated clockwise about the first rotation axis O1 in association with this. When the angle determining lever 194 rotates, the engagement pallet 86 included in the engagement disengaging lever 84 is displaced in the clockwise direction about the first rotation axis O1 with a play in the clockwise direction about the first rotation axis O1. Thus, the engagement/disengagement lever unit 180 can be gradually disengaged from the planetary gear 45 so as to retract the engagement yoke 86 from the rotation locus M of the planetary gear 45. The tip of the stopper tooth 45a moves counterclockwise with respect to the engaging surface 86a while sliding on the engaging surface 86 a.

Fig. 16 is an explanatory view of the operation of the constant torque mechanism according to the second embodiment, and is a plan view of the planetary gear and the engagement/disengagement lever unit as viewed from above.

When the tip of the stopper tooth 45a contacts the first end edge 86a1 of the engaging face 86a, the force F acting between the stopper tooth 45a and the engaging pallet 86 approaches the clockwise direction about the first rotation axis O1. Thereby, the engagement/disengagement lever 84 is displaced clockwise about the first rotation axis O1 with respect to the angle determination lever 194 by the play in the clockwise direction about the first rotation axis O1. Then, as shown in fig. 16, the engagement between the stopper tooth 45a and the engagement yoke shoe 86 is released at the point when the tip of the stopper tooth 45a passes over the first end edge 86a1 of the engagement surface 86 a.

As described above, the constant torque mechanism 130 of the present embodiment includes the angle determining lever 194 that rotates clockwise around the first rotation axis O1 in synchronization with the rotation of the constant force lower sheave 60, instead of the lever spring 94 of the first embodiment. Further, the engagement pallet 86 is rotatable in the clockwise direction about the first rotation axis O1 in accordance with the rotation of the angle determination lever 194, is engageable with and disengageable from the planetary gear 45, and is displaceable relative to the angle determination lever 194 to retreat from the rotation locus M of the planetary gear 45 after being engaged with the planetary gear 45 within the rotation locus M of the planetary gear 45 to restrict the rotation of the planetary gear 45. Thus, as in the first embodiment, it is possible to suppress variation in torque transmitted from the angle determining lever 194 to the escapement 14 via the constant-force lower wheel 60. Therefore, variation in torque transmitted to the escapement 14 can be suppressed.

The angle determination lever 194 includes a fork portion 195 that restricts counterclockwise displacement of the engagement fork shoe 86 engaged with the planetary gear 45 relative to the angle determination lever 194 about the first rotation axis O1. According to this configuration, it is possible to suppress: when the engaging pallet 86 rotates clockwise about the first rotation axis O1 together with the angle determining lever 194, the engaging pallet 86 is displaced counterclockwise about the first rotation axis O1 with respect to the angle determining lever 194 so that the engaging pallet 86 cannot be disengaged from the planetary gear 45. Therefore, the engagement and disengagement operation of the engagement yoke 86 with respect to the planetary gear 45 can be stabilized.

The angle determination lever 194 includes a fork portion 195 that restricts displacement of the engagement fork shoe 86 retracted from the rotation locus M of the planetary gear 45 in the clockwise direction about the first rotation axis O1 with respect to the angle determination lever 194. According to this configuration, it is possible to suppress: after the engagement yoke 86 retreats from the rotation locus M of the planetary gear 45, the engagement yoke 86 is displaced in the clockwise direction about the first rotation axis O1 with respect to the angle determination lever 194 so that the engagement yoke 86 cannot enter the rotation locus M of the planetary gear 45 again to be engaged. Therefore, the engagement and disengagement operation of the engagement yoke 86 with respect to the planetary gear 45 can be stabilized.

[ third embodiment ]

Next, a third embodiment will be described with reference to fig. 17 and 18. In the first embodiment, the engagement pallet 86 is indirectly urged by the spring main body 97 of the lever spring 94 via the lever main body 85. In contrast, the third embodiment differs from the first embodiment in that the engagement shoe 86 is directly biased by the spring portion 294. The configuration other than the following description is the same as that of the first embodiment.

(construction of engaging and disengaging lever Unit)

As shown in fig. 17, the engagement/disengagement lever unit 280 includes a base portion 284 (synchronous rotation portion) and a spring portion 294 instead of the engagement/disengagement lever 84 and the lever spring 94 of the first embodiment.

The base 284 is formed in a ring shape surrounding the first rotation axis O1. The base 284 is inserted into the rod bushing 81 externally and is integrally connected to the rod bushing 81. Thus, the base 284 rotates in the clockwise direction about the first rotation axis O1 in synchronization with the rotation of the constant-force lower sheave 60. An end edge 284a of the base portion 284 that faces the engagement pallet 86 side when viewed in the vertical direction extends in the circumferential direction around the first rotation axis O1. The base portion 284 includes a protruding portion 284b that protrudes radially outward from the end edge 284 a. The projection 284b is adjacent to the end edge 284a in the clockwise direction about the first rotation axis O1. The engagement/disengagement lever unit 280 may be configured such that the base 284 is directly connected to the constant-force lower cylinder 61 of the constant-force lower wheel 60 without providing the lever bushing 81.

The spring portion 294 is a thin plate spring. The spring portion 294 extends counterclockwise around the first rotation axis O1 from the end of the base portion 284 on the engagement pallet 86 side. The spring portion 294 surrounds the base portion 284 radially outward, and extends substantially once around the base portion 284 to a position facing the end edge 284a of the base portion 284 from radially outward. An engagement shoe 86 is attached to a tip end 294a of the spring portion 294. Thereby, the spring portion 294 supports the engagement shoe 86 so as to be displaceable with respect to the base portion 284. The engagement yoke 86 protrudes from the distal end 294a of the spring portion 294 toward the planetary gear 45 (upward). The distal end portion 294a of the spring portion 294 abuts against the end edge 284a of the base portion 284. Thereby, the distal end portion 294a of the spring portion 294 is displaceable in the circumferential direction about the first rotation axis O1 by sliding contact with the end edge 284a of the base portion 284.

The distal end portion 294a of the spring portion 294 is disposed at a distance from the protruding portion 284b of the base portion 284 in the counterclockwise direction about the first rotation axis O1. Further, a portion of the spring portion 294 closer to the base end side than the distal end portion 294a abuts against the protruding portion 284b of the base portion 284 from the clockwise direction about the first rotation axis O1. Thus, the distal end portion 294a of the spring portion 294 can rotate within a predetermined angular range with respect to the base portion 284.

By rotating the base portion 284 in the clockwise direction about the first rotation axis O1, the spring portion 294 is thereby pressed by the protruding portion 284b of the base portion 284 to rotate in the clockwise direction about the first rotation axis O1. Also, the tip end portion 294a of the spring portion 294 is restricted from being displaced in the counterclockwise direction about the first rotation axis O1 with respect to the base portion 284. That is, the projecting portion 284b of the base portion 284 restricts the counterclockwise displacement of the engagement pallet 86 engaged with the planetary gear 45 with respect to the base portion 284 about the first rotation axis O1.

Further, the spring portion 294 urges the snap pallet 86 in the counterclockwise direction about the first rotation axis O1 with respect to the base portion 284, and allows the snap pallet 86 to be displaced in the clockwise direction about the first rotation axis O1 with respect to the base portion 284. In other words, the engagement pallet 86 attached to the distal end portion 294a of the spring portion 294 has a state in which it has a play in the clockwise direction about the first rotation axis O1 with respect to the base portion 284. The spring portion 294 is restricted from rotating in the clockwise direction about the first rotation axis O1 relative to the base portion 284 by the protruding portion 284 b. That is, the projecting portion 284b of the base portion 284 restricts the displacement of the engagement pallet 86 in the counterclockwise direction about the first rotation axis O1 with respect to the base portion 284 after retreating from the rotation locus M of the planetary gear 45.

(function of engaging and disengaging lever unit)

The operation of the engagement and disengagement lever unit 280 configured as described above will be described.

When the constant-force lower pulley 60 is rotated by the power from the constant-force spring 100, the lever bushing 81 and the base 284 are rotated in the clockwise direction about the first rotation axis O1 along with this. When the base 284 rotates, the engagement pallet 86 supported by the spring portion 294 is displaced in the clockwise direction about the first rotation axis O1 with play in the clockwise direction about the first rotation axis O1. Thus, the engagement/disengagement lever unit 280 can be gradually disengaged from the planetary gear 45 so as to retract the engagement yoke 86 from the rotation locus M of the planetary gear 45. The tip of the stopper tooth 45a moves counterclockwise with respect to the engaging surface 86a while sliding on the engaging surface 86 a.

Fig. 18 is an explanatory view of the operation of the constant torque mechanism according to the third embodiment, and is a plan view of the planetary gear and the engagement/disengagement lever unit as viewed from above.

When the tip of the stopper tooth 45a contacts the first end edge 86a1 of the engaging face 86a, the force F acting between the stopper tooth 45a and the engaging pallet 86 approaches the clockwise direction about the first rotation axis O1. Thereby, the engagement pallet 86 is displaced in the clockwise direction about the first rotation axis O1 with respect to the base 284 by the play in the clockwise direction about the first rotation axis O1. Then, as shown in fig. 18, the engagement between the stopper tooth 45a and the engagement yoke shoe 86 is released at the point when the tip of the stopper tooth 45a passes over the first end edge 86a1 of the engagement surface 86 a.

As described above, the constant torque mechanism 230 of the present embodiment includes the base portion 284 of the engagement/disengagement lever unit 280 that rotates in the clockwise direction about the first rotation axis O1 in synchronization with the rotation of the constant force lower sheave 60, instead of the base portion 95 of the lever spring 94 of the first embodiment. Further, the engagement pallet 86 is rotatable in the clockwise direction about the first rotation axis O1 in accordance with the rotation of the base 284, is engageable with and disengageable from the planetary gear 45, and is engaged with the planetary gear 45 within the rotation locus M of the planetary gear 45 to restrict the rotation of the planetary gear 45, and thereafter, the engagement pallet 86 is displaced with respect to the base 284 and can retreat from the rotation locus M of the planetary gear 45. Thus, as in the first embodiment, fluctuation in torque transmitted from the base 284 to the escapement 14 via the constant-force lower wheel 60 can be suppressed. Therefore, variation in torque transmitted to the escapement 14 can be suppressed.

The constant torque mechanism 30 further includes a spring portion 294 that directly biases the engagement yoke shoe 86 toward the inside of the rotation locus M of the planetary gear 45. According to this configuration, it is possible to suppress: the engagement yoke 86 is maintained in a state retracted from the rotation locus M of the planetary gear 45. This stabilizes the engaging and disengaging operation of the engaging yoke 86 with respect to the planetary gear 45.

The engagement pallet 86 is supported by the spring portion 294. With this configuration, the number of components can be reduced compared to a configuration in which the engagement shoe 86 is not supported by the spring portion.

Further, the base portion 284 of the engagement/disengagement lever unit 280 includes a protruding portion 284b that restricts the counterclockwise displacement of the engagement pallet 86 engaged with the planetary gear 45 with respect to the base portion 284 about the first rotation axis O1. According to this configuration, it is possible to suppress: when the engagement pallet 86 rotates clockwise about the first rotation axis O1 together with the base 284, the engagement pallet 86 is displaced counterclockwise about the first rotation axis O1 with respect to the base 284 such that the engagement pallet 86 cannot be disengaged from the planetary gear 45. Therefore, the engagement and disengagement operation of the engagement yoke 86 with respect to the planetary gear 45 can be stabilized.

Further, the base 284 of the engagement/disengagement lever unit 280 includes a protrusion 284b that restricts the clockwise displacement of the engagement pallet 86, which is retracted from the rotation locus M of the planetary gear 45, relative to the base 284 about the first rotation axis O1. According to this configuration, it is possible to suppress: after the engagement pallet 86 retreats from the rotation locus M of the planetary gear 45, the engagement pallet 86 is displaced in the clockwise direction about the first rotation axis O1 with respect to the base 284, and thus the engagement pallet 86 cannot enter the rotation locus M of the planetary gear 45 again and engage therewith. Therefore, the engagement and disengagement operation of the engagement yoke 86 with respect to the planetary gear 45 can be stabilized.

[ fourth embodiment ]

Next, a fourth embodiment will be described with reference to fig. 19 and 20. In the fourth embodiment, the engagement pallet 86 is provided swingably about a third rotation axis O3 different from the first rotation axis O1, unlike the first embodiment. The configuration other than the following description is the same as that of the first embodiment.

(construction of engaging and disengaging lever Unit)

As shown in fig. 19, the engagement/disengagement lever unit 380 supports the engagement pallet 86 so as to be pivotable about the third rotation axis O3. The third rotation axis O3 is located at a position shifted in the in-plane direction of the bottom plate 23 (see fig. 4) with respect to the first rotation axis O1 and the second rotation axis O2. The engagement/disengagement lever unit 380 is fixedly supported by the upper end portion of the constant-force lower drum 61 of the constant-force lower pulley 60. The engagement/disengagement lever unit 380 includes an engagement/disengagement lever 384 and a lever spring 394 instead of the engagement/disengagement lever 84 and the lever spring 94 of the first embodiment.

The rod spring 394 is fixedly supported by the rod bushing 81. The lever spring 394 includes: a base portion 395 (synchronous rotation portion) fixed to the lever bushing 81; and a spring main body 397 (spring portion) extending from the base portion 395.

The base portion 395 is formed in a ring shape surrounding the first rotation axis O1. The base portion 395 is externally inserted into the rod bushing 81 and integrally connected to the rod bushing 81. Thus, the base portion 395 rotates in the clockwise direction about the first rotation axis O1 in synchronization with the rotation of the constant-force lower tier wheel 60. A lever pin 398 (first restriction portion) is provided to protrude from the base portion 395. The lever pin 398 is disposed between the engagement pallet 86 and the first rotation axis O1 when viewed in the vertical direction. The lever pin 398 is formed in a cylindrical shape and protrudes upward from the base portion 395. The engagement/disengagement lever unit 380 may be configured such that the base portion 395 is directly connected to the constant force lower stage cylinder 61 of the constant force lower stage wheel 60 without providing the lever bushing 81.

The spring body 397 is a thin plate spring. The spring main body 397 extends counterclockwise from the end of the base portion 395 on the engagement pallet 86 side. The spring main body 397 radially surrounds the base portion 395 on the outside and extends to a position facing the engagement fork shoe 86 in the counterclockwise direction about the first rotation axis O1 when viewed in the vertical direction.

The engagement disengagement lever 384 is provided so as to be rotatable about the third rotation axis O3 with respect to the base portion 395 of the lever spring 394. The third rotation axis O3 is arranged at a fixed position with respect to the base portion 395 of the lever spring 394. Thereby, the engagement/disengagement lever 384 is provided to be able to revolve around the first rotation axis O1. In the illustrated example, the third rotation axis O3 is arranged radially outward of the lever bushing 81 than the lever pin 398. The engagement/disengagement lever 384 includes a lever main body 385 and an engagement pallet 86 supported by the lever main body 385.

The lever main body 385 is disposed below the planetary gear 45 of the planetary gear 43 and above the base portion 395 of the lever spring 394. The lever main body 385 is supported rotatably with respect to the base 395 by a lever rotation shaft 389 extending along the third rotation axis O3. The lever main body 385 is provided with an engagement pallet 86. Thereby, the engagement pallet 86 is provided swingably about the third rotation axis O3. The engagement fork shoe 86 protrudes from the lever main body 385 toward (above) the planetary gear 45. The engagement pallet 86 is disposed radially outward of the third rotation axis O3 from the lever bushing 81.

The lever body 385 abuts the lever pin 398 from a clockwise direction about the third rotation axis O3. Thus, the lever body 385 is restricted from being displaced in the counterclockwise direction about the third rotation axis O3 by the lever pin 398. That is, the lever spring 394 including the lever pin 398 restricts the counterclockwise displacement of the engagement yoke shoe 86 engaged with the planetary gear 45 with respect to the base portion 395 about the third rotation axis O3.

The lever main body 385 abuts on the tip end of the spring main body 397 of the lever spring 394 from the counterclockwise direction about the third rotation axis O3. Thereby, the lever main body 385 is urged counterclockwise about the third rotation axis O3 with respect to the base portion 395 of the lever spring 394 by the spring main body 397, and displacement in the clockwise direction about the third rotation axis O3 with respect to the base portion 395 is permitted. As described above, the engagement fork shoe 86 attached to the lever main body 385 has a play in the clockwise direction about the third rotation axis O3 with respect to the base portion 395.

Here, the third rotation axis O3 is disposed between the engagement pallet 86 and the first rotation axis O1 in the radial direction of the lever bushing 81. Therefore, the lever pin 398 of the lever spring 394 restricts the displacement of the engagement pallet 86 engaged with the planetary gear 45 with respect to the base portion 395 in the counterclockwise direction about the first rotation axis O1. Further, the engagement pallet 86 is in a state: there is play with respect to the constant force lower sheave 60 in a direction along the clockwise direction about the first rotation axis O1. In addition, the direction along the clockwise direction about the first rotation axis O1 refers to a direction parallel to the clockwise direction about the first rotation axis O1 or slightly inclined with respect to the clockwise direction about the first rotation axis O1. The same is true in the counterclockwise direction about the first rotation axis O1.

(function of engaging and disengaging lever unit)

The operation of the engagement and disengagement lever unit 380 configured as described above will be described.

When the constant force lower wheel 60 is rotated by the power from the constant force spring 100, the base portion 395 of the lever spring 394 is rotated clockwise about the first rotation axis O1 along with this. When the base 395 rotates, the click disengagement lever 384 revolves around the first rotation axis O1 in the clockwise direction. In this way, the engagement pallet 86 included in the engagement/disengagement lever 384 is displaced in the clockwise direction about the first rotation axis O1 while having a play in the clockwise direction about the first rotation axis O1. Thus, the engagement/disengagement lever unit 380 can be gradually disengaged from the planetary gear 45 so as to retract the engagement yoke 86 from the rotation locus M of the planetary gear 45. The tip of the stopper tooth 45a moves counterclockwise with respect to the engaging surface 86a while sliding on the engaging surface 86 a.

Fig. 20 is an explanatory view of the operation of the constant torque mechanism according to the fourth embodiment, and is a plan view of the planetary gear and the engagement/disengagement lever unit as viewed from above.

When the tip of the stopper tooth 45a contacts the first end edge 86a1 of the engaging face 86a, the force F acting between the stopper tooth 45a and the engaging pallet 86 approaches the clockwise direction about the first rotation axis O1. Thus, the engagement pallet 86 is displaced in the clockwise direction about the first rotation axis O1 with respect to the base portion 395 of the lever spring 394 by the play in the clockwise direction about the first rotation axis O1. Then, as shown in fig. 20, the engagement between the stopper tooth 45a and the engagement yoke shoe 86 is released at the point when the tip of the stopper tooth 45a passes over the first end edge 86a1 of the engagement surface 86 a.

As described above, the constant torque mechanism 330 of the present embodiment includes the base portion 395 of the lever spring 394 that rotates clockwise about the first rotation axis O1 in synchronization with the rotation of the constant force lower sheave 60, instead of the base portion 95 of the lever spring 94 of the first embodiment. Further, the engagement pallet 86 is rotatable in the clockwise direction about the first rotation axis O1 in accordance with the rotation of the base portion 395, is engageable with and disengageable from the planetary gear 45, is engaged with the planetary gear 45 within the rotation locus M of the planetary gear 45 to restrict the rotation of the planetary gear 45, and thereafter, is displaced with respect to the base portion 395 and is retractable from the rotation locus M of the planetary gear 45. Thus, as in the first embodiment, it is possible to suppress variation in torque transmitted from the base 395 to the escapement 14 via the constant-force lower wheel 60. Therefore, variation in torque transmitted to the escapement 14 can be suppressed.

The constant torque mechanism 30 further includes a spring main body 397 that indirectly biases the engagement pallet 86 toward the inside of the rotation locus M via the lever main body 385. According to this configuration, it is possible to suppress: the engagement yoke 86 is maintained in a state retracted from the rotation locus M of the planetary gear 45. This stabilizes the engaging and disengaging operation of the engaging yoke 86 with respect to the planetary gear 45.

Further, the base portion 395 of the lever spring 394 includes a lever pin 398 that restricts displacement of the engagement fork shoe 86 engaged with the planetary gear 45 relative to the base portion 395 in the counterclockwise direction about the first rotation axis O1. According to this configuration, it is possible to suppress: when the engagement pallet 86 rotates clockwise about the first rotation axis O1 together with the base portion 395, the engagement pallet 86 is displaced in the counterclockwise direction about the first rotation axis O1 with respect to the base portion 395 so that the engagement pallet 86 cannot be disengaged from the planetary gear 45. Therefore, the engagement and disengagement operation of the engagement yoke 86 with respect to the planetary gear 45 can be stabilized.

Further, the engagement pallet 86 is provided swingably with respect to the base portion 395 of the lever spring 394 about a third rotation axis O3 different from the first rotation axis O1 and the second rotation axis O2. According to this configuration, since the rotation shaft of the engagement yoke shoe 86 is disposed on the third rotation axis O3 different from the first rotation axis O1, the degree of freedom in designing the constant torque mechanism 30 can be improved. Further, the direction in which the engagement yoke shoe 86 is displaced when disengaged from the planetary gear 45 can be inclined with respect to the clockwise direction about the first rotation axis O1. Thus, the direction of the force F acting between the planetary gear 45 and the engagement yoke 86 just before the planetary gear 45 and the engagement yoke 86 disengage can be made to follow the direction of displacement of the engagement yoke 86. This makes it possible to more reliably retract the engagement yoke 86 from the rotation locus M of the planetary gear 45, and to stabilize the engagement and disengagement operation of the engagement yoke 86 with respect to the planetary gear 45.

The present invention is not limited to the above-described embodiments described with reference to the drawings, and various modifications can be considered within the technical scope thereof.

For example, in the above embodiment, the fixed gear 31 is of an external gear type, but the present invention is not limited thereto, and the fixed gear may be of an internal gear type.

In the above embodiment, the constant force upper stage wheel 40 and the constant force lower stage wheel 60 are coaxially arranged, but the present invention is not limited thereto. A gear connected to the constant force upper wheel or the constant force lower wheel may be interposed between the constant force upper wheel and the constant force spring or between the constant force lower wheel and the constant force spring.

In the above embodiment, the tip of the stopper tooth 45a of the planetary gear 45 and the first end edge 86a1 of the engagement surface 86a of the engagement yoke shoe 86 are both formed in the shape of a convex curved surface. The tip of the stopper tooth of the planetary gear and the edge of the engagement surface of the engagement yoke shoe may not be formed in a convex curved surface shape. However, in order to reduce the contact surface pressure between the planetary gear and the engagement yoke shoe and to suppress the scraping of the planetary gear and the engagement yoke shoe, it is desirable that at least one of the tooth tip of the stopper tooth of the planetary gear and the end edge of the engagement surface of the engagement yoke shoe is formed in a convex curved surface shape.

In the above embodiment, the torque adjustment mechanism 110 is provided in the constant torque mechanism, but the torque adjustment mechanism 110 may not be provided. In this case, the inner end portion 102 of the constant force spring 100 may be fixed to the constant force lower stage cylinder 61 in a state where a predetermined preload is applied to the constant force spring 100.

In addition, the components in the above embodiments may be replaced with known components as appropriate without departing from the scope of the present invention, and the above embodiments may be combined as appropriate.

Claims

1. A constant-torque mechanism is characterized in that,

the constant torque mechanism includes:

a planetary carrier that rotates about a first axis by power from a power source;

a planetary gear rotatably supported by the carrier, the planetary gear rotating about a second axis and revolving about the first axis;

a constant force spring that is supplemented with power by rotation of the carrier;

a constant force wheel that rotates by power from the constant force spring and transmits the power of the constant force spring to an escapement;

a synchronous rotation portion that rotates in a first direction about the first axis in synchronization with rotation of the constant force wheel; and

and an engagement claw that rotates in the first direction in accordance with rotation of the synchronous rotating portion and is capable of engaging with and disengaging from the planetary gear, wherein when the engagement claw engages with the planetary gear within a rotation locus of the planetary gear to restrict rotation of the planetary gear, the engagement claw is displaced with respect to the synchronous rotating portion and is capable of retracting from the rotation locus.

2. The constant torque mechanism according to claim 1,

the engagement claw is displaced in a direction along the first direction with respect to the synchronous rotation portion and retreats from the rotation locus.

3. Constant torque mechanism according to claim 1 or 2,

the constant torque mechanism further includes a spring portion that directly or indirectly biases the engagement claw toward the inside of the rotation locus.

4. A constant torque mechanism according to claim 3,

the constant torque mechanism further includes a lever body provided separately from the spring portion, and the lever body supports the engagement claw to be rotatable with respect to the synchronous rotation portion.

5. A constant torque mechanism according to claim 3,

the engagement claw is supported by the spring portion.

6. Constant torque mechanism according to claim 1 or 2,

the synchronous rotating portion includes a first regulating portion that regulates displacement of the engagement pawl engaged with the planetary gear relative to the synchronous rotating portion in a direction along a second direction around the first axis.

7. Constant torque mechanism according to claim 1 or 2,

the synchronous rotation portion includes a second regulating portion that regulates displacement of the engagement claw retracted from the rotation locus in a direction along the first direction with respect to the synchronous rotation portion.

8. Constant torque mechanism according to claim 1 or 2,

the engagement claw is provided swingably about the first axis with respect to the synchronous rotating portion.

9. Constant torque mechanism according to claim 1 or 2,

the engagement claw is provided so as to be swingable about a third axis different from the first axis and the second axis with respect to the synchronous rotating portion.

10. A movement for a clock and watch, which is characterized in that,

the timepiece movement has a constant torque mechanism as claimed in any one of claims 1 to 9.

11. A timepiece, characterized in that it comprises, in a case,

the timepiece has a timepiece movement as claimed in claim 10.