Anti-reverse rotation mechanism and clock

Abstract

To reduce the number of components in a reverse rotation prevention mechanism and a timepiece.SOLUTION: A reverse rotation prevention mechanism 100 includes: a clutch lower gear 50 rotating synchronously with a clutch upper gear 120 for winding up a spring; and a clasp member 10 which allows the clutch lower gear 50 to rotate in a direction of winding up the spring and which prevents it from rotating in a direction of unwinding the spring. The clasp member 10 integrally includes: a clasp part 11 rotatably provided between in states of engaging with teeth 51 of the clutch lower gear 50 and of releasing the engagement with the teeth 51; and a clasp spring part 18 for biasing the clasp part 11 in the engagement state.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a reverse rotation prevention mechanism and a clock.

Background Art

[0002] A winding stem of a clock has a dragon head provided at a portion protruding outward from the main body of the clock. When the dragon head is rotated around the axis of the winding stem, the rotation of the winding stem is transmitted to the fusee, the escape wheel, the circular hole wheel, the square hole wheel, and the barrel arbor. Thereby, the mainspring fixed to the barrel arbor is wound up.

[0003] In order to prevent the wound mainspring from unwinding, the clock is provided with a reverse rotation prevention mechanism that prevents the square hole wheel from rotating in the unwinding direction of the mainspring. The reverse rotation prevention mechanism has a click and a click spring.

[0004] The click is rotatably provided between a posture of meshing with the teeth of the square hole wheel or the teeth of a wheel synchronized with the square hole wheel (hereinafter referred to as the teeth of the square hole wheel or the like) and a posture in which the meshing is disengaged, and by the change in the posture, it is a rigid member that switches the rotation and stop of the square hole wheel.

[0005] The click spring is an elastic member, contacts the click in an elastically deformed state, and biases the click to the above-described meshing posture by the elastic force (restoring force) due to the elastic deformation. The click and the click spring are formed as separate members.

[0006] When winding up the mainspring, the square hole wheel rotates in the forward direction, so that the tooth surface facing forward in the forward direction among the tooth surfaces (tooth surfaces) of the teeth of the square hole wheel or the like presses the click that is meshing with the teeth of the square hole wheel or the like against the elastic force of the click spring. As a result, the click is pushed out to the outside of the tip circle of the teeth of the square hole wheel or the like, and the meshing between the click and the teeth of the square hole wheel or the like is disengaged. The reverse rotation prevention mechanism allows the forward rotation of the square hole wheel, and the mainspring is wound up.

[0007] On the other hand, when the mainspring rotates in the reverse direction, the tooth surface of the ratchet wheel, etc., that faces forward in the reverse direction presses against the pawl. However, since the direction in which this press against the pawl is not set to face outward from the tip circle of the ratchet wheel, etc., the pawl remains engaged with the teeth of the ratchet wheel, etc., without slipping away. As a result, the reverse rotation prevention mechanism prevents the ratchet wheel from rotating in the reverse direction (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2021-117196 [Overview of the project] [Problems that the invention aims to solve]

[0009] By the way, the anti-reverse rotation mechanism described in Patent Document 1 has a pawl, a pawl spring, and a screw for fixing the pawl to the base plate, etc., and has the problem of having a large number of parts.

[0010] This invention has been made in view of the above circumstances, and aims to provide a reverse rotation prevention mechanism and a clock that can reduce the number of parts. [Means for solving the problem]

[0011] The first aspect of the present invention is a reverse rotation prevention mechanism comprising: a gear that rotates in sync with a ratchet wheel that winds a mainspring; and a pawl member that allows the gear to rotate in the direction of winding the mainspring and prevents it from rotating in the direction of unwinding the mainspring, wherein the pawl member integrally comprises a pawl portion that is rotatably provided between a state in which it is meshed with the teeth of the gear and a state in which it is disengaged from the teeth of the gear, and a pawl spring portion that biases the pawl portion to the meshed state.

[0012] The second aspect of the present invention is a clock comprising the reverse rotation prevention mechanism according to the present invention and the square-hole wheel. [Effects of the Invention]

[0013] According to the anti-reverse rotation mechanism and clock of the present invention, the number of parts can be reduced. [Brief explanation of the drawing]

[0014] [Figure 1] This diagram shows a watch movement equipped with a reverse rotation prevention mechanism. [Figure 2] This is a plan view of the main part of the anti-reverse rotation mechanism, showing the state in which the clasp portion of the clasp member is engaged with the teeth of the clutch lower gear. [Figure 3] Figure 2 shows the state in which the clutch upper gear has been virtually removed. [Figure 4] This is a plan view of the main part of the anti-reverse rotation mechanism, showing the state in which the locking part of the locking member and the teeth of the clutch lower gear are disengaged. [Figure 5] Figure 4 shows the state in which the clutch upper gear has been virtually removed. [Figure 6] This is a perspective view showing the upper clutch gear and lower clutch gear integrated into a single unit. [Figure 7] This is a perspective view showing the lower clutch gear with the upper clutch gear removed from the state shown in Figure 6. [Figure 8] This is a perspective view of a single kohaze component. [Modes for carrying out the invention]

[0015] Hereinafter, embodiments of the anti-reverse rotation mechanism and clock according to the present invention will be described with reference to the drawings.

[0016] (composition) FIG. 1 is a view showing the movement of the timepiece 200 provided with the reverse rotation prevention mechanism 100, and FIGS. 2 to 5 are partial plan views showing the reverse rotation prevention mechanism 100. FIGS. 2 and 3 show a state in which the engaging portion 11 of the engaging member 10 meshes with the teeth 51 of the clutch lower gear 50, and FIGS. 4 and 5 show a state in which the clutch upper gear 120 rotates in the forward direction and the engagement between the engaging portion 11 and the teeth 51 of the clutch lower gear 50 is released, respectively.

[0017] Note that FIG. 3 shows a state in which the clutch upper gear 120 is virtually removed in order to make it easier to see the state in which the clutch lower gear 50 and the engaging portion 11 are engaged in the state shown in FIG. 2, and FIG. 5 shows a state in which the clutch upper gear 120 is virtually removed in order to make it easier to see the state in which the engagement between the clutch lower gear 50 and the engaging portion 11 is released in the state shown in FIG. 4.

[0018] FIG. 6 is a perspective view showing a state in which the clutch upper gear 120 and the clutch lower gear 50 are integrally provided, and FIG. 7 is a perspective view showing the clutch lower gear 50 in a state where the clutch upper gear 120 is removed from the state shown in FIG. 6. FIG. 8 is a perspective view of the engaging member 10 alone.

[0019] The illustrated timepiece 200 is an embodiment of the timepiece according to the present invention. Also, the illustrated reverse rotation prevention mechanism 100 is an embodiment of the reverse rotation prevention mechanism according to the present invention.

[0020] As shown in FIGS. 1 and 2, the timepiece 200 is provided with a reverse rotation prevention mechanism 100 in the movement. As shown in FIGS. 1 to 5, the reverse rotation prevention mechanism 100 includes an engaging member 10 and a clutch gear 50.

[0021] As shown in Figure 6, the lower clutch gear 50 is coaxial with the upper clutch gear 120, sharing a common shaft C2, and is superimposed on the upper clutch gear 120 in the thickness direction, and is integrally provided with the square bore wheel 120 via the clutch ratchet mechanism 70 shown in Figure 7. The clutch wheel 50 rotates around shaft C2 together with the upper clutch gear 120 via the clutch ratchet mechanism 70. Therefore, the lower clutch gear 50 rotates around shaft C2 in synchronization with the upper clutch gear 120. The lower clutch gear 50 may be formed integrally with the upper clutch gear 120.

[0022] Here, the clutch upper gear 120 is configured to be linked to the winding stem of the clock 200, and the automatic winding rotor is sequentially transmitted to the clutch upper gear 120, the clutch ratchet mechanism 70, the clutch lower gear 50, the clutch pinion 81, the reduction gear (not shown), and the ratchet wheel, which are examples of an automatic winding mechanism. As a result, the mainspring, one end of which is fixed to the barrel arbor that forms the axis of the ratchet wheel, is wound up.

[0023] For example, in Figures 2, 4, and 6, the clutch cannon 81 rotates clockwise (right-hand) around axis C2, as indicated by arrow R, causing the linked reduction gear to rotate and wind the mainspring, and then rotates counterclockwise (left-hand) as indicated by arrow -R to unwind the wound mainspring.

[0024] The clutch lower gear 50 has teeth 51 formed on its outer circumference. The teeth 51 are not teeth that mesh with the teeth of other gears, but are formed as teeth of a ratchet mechanism that engages with the clasp portion 11 described later, and have a tooth profile similar to that of a sawtooth.

[0025] Specifically, in the state shown in Figures 2, 4, and 6, when rotating clockwise around axis C2 (rotation in the direction of winding the mainspring), the tooth surface 51a on the front side has a shallower (smaller) inclination angle with respect to the tangent of the tip circle of the tooth 51 of the clutch lower gear 50 compared to the tooth surface 51b on the rear side.

[0026] Furthermore, the inclination angle of the front tooth surface 51a with respect to the tangent to the tip circle of the tooth 51 of the clutch lower gear 50 is formed to be, for example, 35 to 45 degrees, and the inclination angle of the rear tooth surface 51b with respect to the tangent to the tip circle of the tooth 51 of the clutch lower gear 50 is formed to be, for example, approximately 90 degrees.

[0027] The number of teeth 51 on the lower clutch gear 50 is the same as the number of teeth 121 on the upper clutch gear 120. The number of teeth 51 on the lower clutch gear 50 does not have to be the same as the number of teeth 121 on the upper clutch gear 120; therefore, it may be more or less than the number of teeth 121 on the upper clutch gear 120.

[0028] The clutch ratchet mechanism 70 comprises a sun gear 71 and a planetary gear 72. The clutch ratchet mechanism 70 transmits only one rotation of the upper clutch gear 120 to the lower clutch gear 50. Since the lower clutch gear 50 is fixed to the clutch pinion 81, the rotation of the lower clutch gear 50 is transmitted to the clutch pinion 81, and from the clutch pinion 81, the rotation is transmitted to the square hole gear via a reduction gear (not shown).

[0029] As shown in Figure 8, the fastener member 10 comprises a fastener portion 11 and a fastener spring portion 18. The fastener portion 11 and the fastener spring portion 18 are each part of the fastener member 10. Therefore, the fastener portion 11 and the fastener spring portion 18 are formed integrally. The fastener member 10 is formed in a roughly V-shape by the fastener portion 11 and the fastener spring portion 18.

[0030] The clasp member 10 is formed, for example, by cutting a flat metal plate of uniform thickness into a predetermined shape by press working, bending it, and shaping it into a roughly V-shape in plan view. However, the method of forming the clasp member 10 is not limited to the press working method described above.

[0031] The clasp portion 11 has a flat plate portion 11a and an arm portion 11c. The flat plate portion 11a is positioned parallel to the clutch upper gear 120 and the clutch lower gear 50 in the movement of the clock 200. In other words, the clasp member 10 is positioned in the movement such that the thickness direction of the flat plate portion 11a coincides with the thickness direction of the clock 200.

[0032] A support hole 11b is formed in the flat plate portion 11a. An axis perpendicular to the flat plate portion 11a is passed through the support hole 11b, and this axis is fixed to the base plate or the like of the movement of the clock 200. As a result, the clasp portion 11 is supported so as to be able to rotate around the center C1 of the axis that passes through the support hole 11b.

[0033] The arm portion 11c is formed by bending downward so as to be perpendicular to the flat plate portion 11a. The arm portion 11c has a clutch claw 11d (an example of a claw) and a flange portion 11e. The flange portion 11e is formed on the side of the arm portion 11c that is further from the center C1 than the clutch claw 11d, and on the tip side of the arm portion 11c. The clutch claw 11d is formed on the side of the arm portion 11c that is closer to the flat plate portion 11a than the flange portion 11e.

[0034] The clasp member 10 is positioned in the movement of the clock 200 such that, in the thickness direction of the clock 200, the height range is such that the clutch pawl 11d engages with the teeth 51 of the clutch lower gear 50. The clasp member 10 can be displaced between a state in which the clutch pawl 11d engages with the teeth 51 of the clutch lower gear 50 (see Figures 2 and 3) and a state in which the clutch pawl 11d and the teeth 51 are disengaged (see Figures 4 and 5) by the rotation around the center C1 described above.

[0035] Specifically, as the clutch lower gear 50 rotates clockwise (in the direction of arrow R), the clutch pawl 11d, which is engaged with the teeth 51 of the clutch lower gear 50 (see Figure 3), is pushed outward from the tip circle of the clutch lower gear 50 by the tooth surface 51a of the tooth 51 that is facing forward in the rotational direction relative to the clutch pawl 11d.

[0036] This pressure causes the clasp 11 to rotate counterclockwise around the center C1 (arrow R direction). As a result, the clutch pawl 11d is displaced radially outward from the tip circle of the teeth 51 of the clutch lower gear 50, disengaging the clutch pawl 11d from the teeth 51 of the clutch lower gear 50 (Figures 4 and 5), allowing the clutch lower gear 50 to rotate clockwise (arrow R direction). This winds the mainspring that was wound inside the barrel via the clutch pinion 81, reduction gear, and ratchet wheel.

[0037] On the other hand, when the lower clutch gear 50 rotates counterclockwise (in the direction of arrow R), the clutch pawl 11d, which is engaged with the teeth 51 of the lower clutch gear 50 (see Figure 2), is pushed by the tooth surface 51b of the tooth 51 that is behind the clutch pawl 11d in the rotational direction, in a direction perpendicular to the tooth surface 51b. As a result, a rotational moment is generated in the pawl portion 11 clockwise (in the direction of arrow R) around the center C1, but this rotational moment does not displace the clutch pawl 11d outside the tip circle of the teeth 51 of the lower clutch gear 50.

[0038] Therefore, the clutch pawl 11d and the teeth 51 of the clutch lower gear 50 remain engaged (Figures 2 and 3), preventing the clutch lower gear 50 from rotating counterclockwise (arrow-R direction). This causes the mainspring, which was wound inside the barrel, to unwind.

[0039] The flange portion 11e is formed at the tip of the flat plate portion 11a that is further away from the flat plate portion 11a than the clutch pawl 11d, in the thickness direction of the flat plate portion 11a. Specifically, with the clutch pawl 11d positioned to engage with the teeth 51 of the clutch lower gear 50 at a height range, the flange portion 11e is positioned on the lower surface side of the clutch lower gear 50 (the side opposite to the surface facing the clutch upper gear 120 (the top surface) in the thickness direction of clockwise 200) so as not to come into contact with the clutch lower gear 50.

[0040] As a result, when the clasp member 10 is displaced upward in the thickness direction relative to the clutch lower gear 50, the flange portion 11e abuts against the lower surface of the clutch lower gear 50 in the thickness direction, preventing the clasp member 10 from being displaced any further upward. This also prevents the clutch pawl 11d of the flange portion 11 from moving upward relative to the clutch lower gear 50, thereby disengaging the clutch pawl 11d from the teeth 51.

[0041] Therefore, to prevent the clasp member 10 from being displaced upward, it is not necessary to fix the clasp member 10 to the base plate or the like with screws. The clasp member 10 can be held to the base plate or the like simply by passing the shaft fixed to the base plate or the like through the support hole 11b of the flat plate portion 11a. Thus, a screw member for fixing the clasp member 10 to the base plate or the like becomes unnecessary.

[0042] In conventional anti-reverse mechanisms to which the present invention does not apply, where the clasp and clasp spring are composed as separate parts, a screw member for fixing the clasp to the base plate or the like, and a screw member for fixing the clasp spring to the base plate or the like were required. Therefore, the anti-reverse mechanism 100 can reduce the number of screw members by two compared to such conventional anti-reverse mechanisms.

[0043] The flat plate portion 11a has a projection 11g that protrudes radially outward from the center C1 at a position different from the position where the arm portion 11c is formed. This projection 11g is the part where a finger is placed to input the operation of rotating the clasp portion 11 counterclockwise around the center C1.

[0044] By pushing the projection 11g in the direction of arrow f1 (see Figures 4 and 5), the clasp 11 is rotated counterclockwise around the center C1 (in the direction of arrow R), moving the clutch pawl 11d, which is engaged with the teeth 51 of the clutch lower gear 50 (Figure 2), to the outside of the tip circle of the clutch lower gear 50, thereby switching to a state where the engagement between the clutch pawl 11d and the teeth 51 is released (Figures 4 and 5).

[0045] As will be described later, a bent portion 18b, which is a spring pressing portion, is formed at the end of the clasp spring portion 18. This bent portion 18b is formed to input an operation that rotates the clasp portion 11 counterclockwise around the center C1, similar to the projection portion 11g. Therefore, the projection portion 11g, which can perform the same function as the bent portion 18b, is not necessary.

[0046] A connecting portion 11f is formed on the flat plate portion 11a, on the side opposite to the arm portion 11c, with the support hole 11b in between. The connecting portion 11f is parallel to the flat plate portion 11a and has a step in the thickness direction, on the side opposite to the arm portion 11c relative to the flat plate portion 11a. The connecting portion 11f is the part that connects to the snap spring portion 18.

[0047] Since the clasp member 10 is formed by bending a metal plate, the clasp portion 11 and the clasp spring portion 18 are formed with uniform (equal) thickness. Furthermore, the clasp portion 11 functions as a rigid body that hardly undergoes elastic deformation under load in the in-plane direction of a surface substantially parallel to the clutch lower gear 50. In other words, the clasp portion 11 is a rigid body portion with respect to load around the center C1.

[0048] Therefore, as shown in Figures 2-5, even when the teeth 51 of the lower clutch gear 50 apply a pressing force to the clutch pawl 11d in a direction along the surface of the flat plate portion 11a, the clasp portion 11 hardly undergoes elastic deformation. Instead, it rotates around the center C1 as a rigid body due to the torque around the center C1 corresponding to the applied pressing force.

[0049] The clasp spring portion 18 is formed by bending downward from the end of the connecting portion 11f in a direction perpendicular to the surface of the connecting portion 11f. The clasp spring portion 18 as a whole is formed to extend linearly in a certain direction. The clasp spring portion 18 is formed to be longer than the clasp portion 11. However, the clasp spring portion 18 may be formed to be shorter than the clasp portion 11.

[0050] Unlike the clasp portion 11, the clasp spring portion 18 functions as an elastic portion that elastically bends in response to loads in the in-plane direction of a surface substantially parallel to the clutch lower gear 50, specifically loads that intersect the longitudinal direction of the clasp spring portion 18.

[0051] The clasp spring portion 18 has a spring portion 18a, a contact portion 18c, a bent portion 18b, and a connecting portion 18d. The connecting portion 18d is formed on the side of the clasp spring portion 18 closest to the clasp portion 11 and is connected to the connecting portion 11f of the clasp portion 11. The portion where the connecting portion 11f and the connecting portion 18d are connected forms the apex angle of the roughly V shape which is the shape of the clasp member 10.

[0052] The spring portion 18a is connected to the connecting portion 18d, and the width perpendicular to the longitudinal direction of the spring portion 18 is formed to be narrower than the other parts, and the length along the longitudinal direction is formed to be longer than the other parts. As a result, the spring portion 18a has the highest flexibility (is the most flexible) in the direction perpendicular to the longitudinal direction compared to the other parts of the spring portion 18.

[0053] The contact portion 18c is formed on the opposite side of the spring portion 18a from the connecting portion 18d, that is, on the end side of the clasp spring portion 18, and is connected to the spring portion 18a. The contact portion 18c is the part that contacts the spring stopper portion 80, which is provided on the outer side of the roughly V shape of the clasp member 10 in a plan view, when the clasp member 10 is attached to a predetermined position in the movement of the clock 200 (with the shaft passed through the support hole 11b and supported on the base plate, etc.).

[0054] At this time, as shown in Figures 2 to 5, the clasp member 10 is in a state where the clutch pawl 11d is engaged with the teeth 51 of the clutch lower gear 50.

[0055] The spring stopper portion 80 is formed in a position where the spring portion 18a of the fastener member 10, which is attached to a predetermined position on the movement, is elastically bent in a direction that narrows the apex angle of the approximately V shape of the fastener member 10 (in Figures 2 to 5, the spring portion 18a is bent so that it is convex downwards) and contacts the contact portion 18c.

[0056] As a result, the clasp member 10 is subjected to a rotational moment that rotates clockwise around the center C1 (in the direction of arrow R), and therefore, the clasp member 10, when mounted in a predetermined position, biases the clutch pawl 11d in a direction that presses it against the tooth surface 51a of the clutch lower gear 50 (towards the radially inward direction of the clutch lower gear 50).

[0057] Furthermore, the spring stopper portion 80 is preferably a fixed part formed on the base plate of the movement, and is in contact with the contact portion 18c, allowing the contact portion 18c to slide smoothly. Therefore, in order to improve the sliding properties (ease of sliding) with the contact portion 18c, the spring stopper portion 80 is preferably formed on the circumferential surface of a cylinder.

[0058] The bent portion 18b is formed at the end of the crimp spring portion 18 opposite to the connecting portion 18d. The bent portion 18b is formed by bending in a direction perpendicular to the contact portion 18c. The bent portion 18b is a part to which pressing force can be applied by a finger or the like along the direction of arrow f2 (see Figures 4 and 5) in the longitudinal direction of the crimp spring portion 18.

[0059] When a pressing force is applied to the bent portion 18b along the direction of arrow f2 described above, this pressing force is input to the connection portion 11f of the fastener portion 11 via the connection portion 18d of the fastener spring portion 18. The pressing force applied to the connection portion 11f then generates a rotational moment in the fastener member 10, including the fastener portion 11, that causes it to rotate counterclockwise around the center C1 (in the direction of arrow R).

[0060] This rotational moment causes the clasp member 10 to rotate counterclockwise around the center C1, displacing the clutch pawl 11d outward from the tip circle of the tooth 51 of the clutch lower gear 50, resulting in a state where the engagement between the clutch pawl 11d and the tooth 51 is released (Figures 4 and 5).

[0061] As a result, the restriction on the lower clutch gear 50 to rotate counterclockwise (arrow-R direction) is removed, allowing the clutch pinion 81 to rotate counterclockwise and the mainspring that was wound inside the barrel to unwind.

[0062] Furthermore, when the clasp member 10 rotates counterclockwise around the center C1 due to the rotational moment described above, the spring portion 18a of the clasp spring portion 18 becomes elastically bent downwards in Figures 4 and 5, and an elastic force is generated in the direction in which the bending disappears.

[0063] Therefore, when the pressure applied to the bent portion 18b in the direction of arrow f2 is removed, the elastic force in the direction that eliminates the deflection returns it to its pre-deflection state, and the clutch pawl 11d returns to the state in which it engages with the teeth 51 of the clutch lower gear 50. This stops the mainspring inside the barrel from unwinding.

[0064] (action) As described above, in the clock 200 and reverse rotation prevention mechanism 100 of this embodiment, the clutch pawl 11d of the clasp member 10 engages with the teeth 51 of the clutch lower gear 50, as shown in Figures 2 and 3. Due to the elastic force of the spring portion 18a, the clutch pawl 11d presses the tooth surface 51a of the teeth 51 radially inward of the clutch lower gear 50. In other words, the clasp spring portion 18 biases the clasp portion 11 and the clutch lower gear 50 into a meshed state.

[0065] Here, when the automatic winding rotor is rotated to wind the mainspring of the barrel wheel in the movement of the watch 200, that rotation is transmitted to the clutch upper gear 120. When the mainspring is being wound, the clutch upper gear 120 rotates clockwise (in the direction of arrow R) in Figures 2-5.

[0066] The upper clutch gear 120 rotates the lower clutch gear 50 in sync with it via the clutch ratchet mechanism 70. Therefore, the lower clutch gear 50 also rotates clockwise (in the direction of arrow R).

[0067] Here, as described above, the teeth 51 of the clutch lower gear 50 are pressed by the clutch pawl 11d to suppress their rotation. However, if the torque that rotates the clutch lower gear 50 exceeds the torque that the clutch pawl 11d uses to suppress the rotation of the clutch lower gear 50, the tooth surfaces 51a of the teeth 51 of the clutch lower gear 50 rotate while pushing the clutch pawl 11d radially outward, as shown in Figures 4 and 5.

[0068] When the clutch pawl 11d is pushed radially outward from the clutch lower gear 50, this upward load corresponds to an in-plane load on the clasp portion 11. Since the clasp portion 11 is a rigid body with respect to this in-plane load, the upward load received from the clutch lower gear 50 causes the clasp portion 11 to rotate counterclockwise around the center C1 (in the direction of arrow R).

[0069] As a result, the connecting portion 11f of the clasp portion 11 rotates upward in the diagram compared to the state shown in Figures 2 and 3, and the connecting portion 18d at the right end of the clasp spring portion 18 also rotates upward in the diagram. At this time, the contact portion 18c on the left end of the clasp spring portion 18 is in contact with the spring stopper portion 80, so the downward rotation shown in accordance with the rotation of the connecting portion 18d is prevented.

[0070] Therefore, with the contact portion 18c of the clasp spring portion 18 in contact with the spring stopper portion 80, the connecting portion 18d is displaced upward, causing the spring portion 18a to be elastically bent downward. Due to the bending of the spring portion 18a, a torque is generated in the clasp member 10 that attempts to rotate it clockwise around the center C1 (in the direction of arrow R).

[0071] Then, when the tooth surface 51a of the tooth 51 of the clutch lower gear 50 pushes the clutch pawl 11d up to the outside of the tip circle of the clutch lower gear 50, the tooth 51 moves forward in the rotational direction relative to the clutch pawl 11d. As a result, the clutch pawl 11d moves over the tooth 51, and due to the torque caused by the deflection of the spring portion 18a described above, the clasp member 10 rotates clockwise around the center C1, and the clutch pawl 11d comes into contact with the tooth surface 51a of the tooth 51 that follows the tooth 51 that has moved forward.

[0072] In this way, the mainspring can be wound by the clockwise rotation of the clutch upper gear 120.

[0073] On the other hand, when the automatic winding rotor is not being rotated, the clutch lower gear 50 does not rotate clockwise, but the wound mainspring exerts torque in the direction that unwinds the mainspring, that is, in the direction of counterclockwise rotation (arrow R direction).

[0074] However, even if the clutch lower gear 50 tries to rotate counterclockwise, the tip of the clutch pawl 11d of the clasp member 10 abuts against the tooth surface 51b of the tooth 51 of the clutch lower gear 50, and receives a rotational moment from the tooth surface 51b that causes the clasp member 10 to rotate clockwise (in the direction of arrow R).

[0075] Therefore, the clutch pawl 11d remains engaged with the teeth 51 of the clutch lower gear 50, preventing the clutch lower gear 50 from rotating counterclockwise, and thus preventing the mainspring from being unwound by the counterclockwise rotation of the clutch pinion 81 fixed to the clutch lower gear 50.

[0076] As described in detail above, according to the clock 200 and reverse rotation prevention mechanism 100 of this embodiment, the clasp member 10, in which the clasp portion 11 and the clasp spring portion 18 are integrally formed, can perform the same function as a reverse rotation prevention mechanism composed of a separate clasp and clasp spring.

[0077] Therefore, the clock 200 and the anti-reverse rotation mechanism 100 of this embodiment can reduce the number of parts compared to an anti-reverse rotation mechanism in which the clasp and clasp spring are configured as separate components.

[0078] Furthermore, in this embodiment, the clock 200 and the anti-reverse rotation mechanism 100 can be easily manufactured by a press working process in which a rigid part, the clasp part 11, and an elastic part, the clasp spring part 18, are integrated into a single clasp member 10, which is formed by cutting a flat metal plate of uniform thickness into a predetermined shape and bending it. Therefore, the anti-reverse rotation mechanism 100 of this embodiment can reduce manufacturing costs compared to one in which a rigid part and an elastic part are formed separately and then integrated.

[0079] Furthermore, in this embodiment, when the clasp member 10 moves (lifts up) in the thickness direction of the clock 200 so that the clutch pawl 11d disengages from the teeth 51 of the clutch lower gear 50 upward on the shaft C2 in Figures 6 and 7, the flange portion 11e abuts against the lower surface of the clutch lower gear 50 (in Figure 6, the surface of the clutch lower gear 50 opposite to the surface facing the clutch upper gear 120 (the upper surface)), preventing the clasp member 10 from moving to a position where the clutch pawl 11d disengages from the teeth 51.

[0080] Therefore, there is no need to provide fixing members such as screws to secure the clasp member 10 to the base plate or the like in order to prevent the clasp member 10 from moving in the thickness direction of the clock 200. In other words, in the case without the flange portion 11e, it is necessary to use fixing members such as screws to secure the clasp member 10 to the base plate or the like in order to prevent the clasp member 10 from floating up, but in this embodiment the clasp member 10 has a flange portion 11e, there is no need to provide fixing members such as screws.

[0081] Furthermore, in reverse rotation prevention mechanisms to which the present invention does not apply, where the clasp and clasp spring are composed of separate components, it is necessary to fix the clasp spring to the base plate or the like using a fixing member such as a screw, independently of the clasp. However, in the reverse rotation prevention mechanism of the present invention, the clasp part and the clasp spring part are composed of an integrated unit. Therefore, by preventing the clasp part from lifting up with the flange part, the lifting up of the clasp spring part can also be prevented, and a fixing member for fixing the clasp spring becomes unnecessary.

[0082] Furthermore, in this embodiment, the reverse rotation prevention mechanism 100 has a bent portion 18b formed in the clasp spring portion 18. The bent portion 18b functions as an operating part that, when pressed with a finger or the like, releases the engagement between the clutch pawl 11d and the teeth 51 of the clutch lower gear 50, thereby allowing the clutch pinion 81 to rotate in the reverse direction (rotation in the direction of unwinding the mainspring (arrow-R direction)).

[0083] Furthermore, since the bent portion 18b can be pressed with a finger or the like without removing the clasp member 10 itself or the surrounding parts that are overlapped and cover at least a part of the clasp member 10, when disassembling the movement for purposes such as repair or overhaul of the watch 200, the mainspring can be unwound beforehand before removing the clasp member 10 itself or the surrounding parts, thereby alleviating the difficulty of disassembling the watch while the mainspring is wound.

[0084] The reverse rotation prevention mechanism 100 of this embodiment is configured by combining a clutch lower gear 50, which forms part of the automatic winding mechanism and synchronizes with the ratchet wheel, and a clasp member 10. However, the gear that the clasp member 10 meshes with is not limited to the clutch lower gear 50, but can be any gear that rotates in synchronization with the ratchet wheel. Therefore, the reverse rotation prevention mechanism 100 may not be a gear provided on the same axis C2 as the clutch upper gear 120, as is the clutch lower gear 50, but rather a combination of a gear configured to mesh with the clutch upper gear 120 and a clasp member 10 that restricts the rotation of that gear.

[0085] The anti-reverse rotation mechanism according to the present invention is not limited to a combination of a gear that rotates in sync with the square-hole wheel and a tack member, but may also consist only of a tack member that directly restricts the rotation of the square-hole wheel itself. [Explanation of symbols]

[0086] 10. Clasp member 11 Kohaze Club 18. Kohaze spring section 50 Clutch lower gear (gear) 100 Anti-reverse rotation mechanism 120 Clutch upper gear 200 clocks C1 center C2 axis

Claims

1. A gear that rotates in sync with the square-hole wheel that winds the mainspring, The gear comprises a pawl member that allows rotation in the direction of winding the mainspring and prevents rotation in the direction of unwinding the mainspring, The aforementioned clasp member is, A clasp portion is provided to be rotatable between a state in which it is engaged with the teeth of the gear and a state in which it is disengaged from the teeth of the gear, The system integrally includes a clasp spring that biases the clasp portion to the engaged state, The teeth of the gear are formed such that the tooth surface facing forward during rotation in the winding direction of the mainspring has a shallower inclination angle with respect to the tip circle of the gear compared to the tooth surface facing backward. The pawl portion that meshes with the teeth of the gear is pressed from the front tooth surface toward the outside of the tip circle of the gear when the mainspring is rotated in the winding direction. The aforementioned clasp portion is a reverse rotation prevention mechanism, in which, when the mainspring rotates in the direction of unwinding, it is pressed from the tooth surface that is on the rear side in the direction of winding the mainspring in a direction perpendicular to the tooth surface that is on the rear side.

2. The aforementioned clasp portion and the aforementioned clasp spring portion are formed in a substantially V-shape, The aforementioned clasp portion has a claw on the end opposite to the connecting portion connected to the clasp spring portion that engages with the teeth of the gear, The aforementioned snap spring portion biases the snap portion such that the pawl engages with the teeth of the gear, The reverse rotation prevention mechanism according to claim 1, wherein the gear rotates the pawl portion such that the pawl is released when the gear rotates in the direction of winding the mainspring.

3. The reverse rotation prevention mechanism according to claim 2, wherein the fastener portion has a flange portion at the end side that is ahead of the claw, which abuts against the surface of the gear, thereby preventing the fastener portion from lifting up so that the claw disengages from the teeth of the gear.

4. The reverse rotation prevention mechanism according to claim 2, wherein the crimp spring portion has an operating portion at the end opposite to the connecting portion, which rotates the crimp portion to the released state by applying a pressing force along the crimp spring portion.

5. The aforementioned fastener member is formed by surfaces having a uniform thickness and oriented perpendicularly to each other, with the fastener portion and the fastener spring portion having a uniform thickness. The aforementioned clasp portion functions as a rigid body portion against loads in the in-plane direction substantially parallel to the gear, The anti-reverse rotation mechanism according to any one of claims 1 to 4, wherein the aforementioned spring portion functions as an elastic portion against a load in a plane substantially parallel to the gear.

6. A reverse rotation prevention mechanism according to any one of claims 1 to 4, A clock equipped with the aforementioned square-hole wheel.

7. The reverse rotation prevention mechanism described in claim 5, A clock equipped with the aforementioned square-hole wheel.

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