Retractor for seat belt

Abstract

To provide a retractor for a seat belt which can reduce incidental lock-up when an entire part of a belt is pulled out.SOLUTION: A retractor for a seat belt includes: a switch lever which is pivotally supported by a bearing plate and displaced between a lock canceling position where the switch lever does not engage with an external tooth of a latch ring and prevents locking by a car sensor lever and a non-lock canceling position where the switch lever engages with the external tooth of the latch ring and allows lock by the car sensor lever; and a first disc which rotates in response to rotation of a spindle. A first contact part provided at an outer peripheral part of the first disc contacts with the switch lever and thereby displaces the switch lever to the lock canceling position when a length of a pulled out portion of the seat belt is maximum.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a seat belt retractor. [Background technology]

[0002] Conventionally, as a seat belt retractor for safely holding a vehicle occupant in a seat, an emergency locking retractor has been used which is equipped with an emergency locking mechanism that physically locks the withdrawal of the seat belt (webbing) by a vehicle body acceleration sensing means that reacts to sudden acceleration, collision, or deceleration, thereby effectively and safely restraining the occupant.

[0003] For example, there are the following types of emergency locking mechanisms: One detects a sudden withdrawal of the seat belt and prevents the rotation of the spindle in the seat belt withdrawal direction (webbing acceleration sensing means: WS (Webbing Sensor)), and the other detects a sudden deceleration state of the vehicle and prevents the rotation of the spindle in the seat belt withdrawal direction (vehicle acceleration sensing means: CS (Car Sensor)). In either case, the spindle is locked by the rocking of a locking member that rotates together with the spindle, causing the claws of the locking member to engage with internal teeth of a frame that supports the spindle (see, for example, Patent Documents 1 and 2).

[0004] In such a retractor, end lock (a phenomenon in which the spindle cannot rotate in the belt-withdrawing direction or the belt-retracting direction) can occur in the following three cases. (1) Caused by inadvertent activation of the webbing acceleration sensing means (WS). Generally, webbing acceleration sensing means operates on the principle that when the belt is rapidly pulled out, the inertia of the mass causes the rotation of the mass to lag behind the spindle, causing the locking member to jump outward and engage with the internal teeth of the frame. However, if the webbing becomes taut after being rapidly wound up, the momentum of the mass moves relative to the spindle, causing the locking member to engage with the internal teeth of the frame. (2) Caused by inadvertent activation of the vehicle acceleration sensing means (CS). When acceleration is input to the vehicle body acceleration sensing means due to vibration of the retractor caused by rapid winding of the webbing, etc., the ball, which is an inertial member, moves, causing the lever to swing and engage with the latch member, thereby locking it. (3) Inadvertent operation of the locking member itself. This occurs when the force of winding up the seat belt causes the locking member itself to become caught in the internal teeth of the frame.

[0005] Patent Document 3 describes a seat belt retractor that can prevent end lock of both the webbing acceleration sensing means and the vehicle body acceleration sensing means with a simple configuration.

[0006] Other seat belt retraction locking mechanisms include an automatic locking function (ALR: Automatic Locking Retractor) that prevents the seat belt from rotating in the retracting direction when the seat belt is fully retracted until a specified amount of the seat belt has been retracted. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 9-58410 [Patent Document 2] Japanese Patent Application Publication No. 10-129417 [Patent Document 3] Patent No. 5748712 Summary of the Invention [Problem to be solved by the invention]

[0008] When the seat belt is fully withdrawn with force, the belt winding shaft may overrun and skip teeth, causing the synchronization to be lost and resulting in lockup. The object of the present disclosure is to provide a seat belt retractor that limits the locking operation when the seat belt is fully withdrawn. [Means for solving the problem]

[0009] A seat belt retractor according to one aspect of the present disclosure includes a spindle rotatably supported by a frame and around which a seat belt is wound, a bearing plate fixed to the frame, a latch ring having internal teeth and external teeth formed on its inner and outer circumferential surfaces, respectively, and rotatably disposed on the bearing plate, a steering disk arranged coaxially with the latch ring, having external teeth formed on its outer circumferential surface, and supported by the spindle so as to be rotatable together with the latch ring, a webbing sensor lever pivotally supported by the steering disk at a position where it can be engaged with and disengaged from the internal teeth of the latch ring, and displaced between a first operating position in which it engages with the internal teeth of the latch ring and a first inoperative position in which it does not engage with the internal teeth of the latch ring, and a car sensor lever pivotally supported by a housing provided on the bearing plate at a position where it can be engaged with and disengaged from the external teeth of the steering disk, and displaced between a second operating position in which it engages with the external teeth of the steering disk and a second inoperative position in which it does not engage with the external teeth of the steering disk in response to an acceleration acting thereon. The tractor comprises a switch lever rotatably supported on a bearing plate, the switch lever displaceable between a lock canceling position in which it does not engage with the external teeth of a latch ring and prevents the car sensor lever from being displaced to the second operating position, and a non-lock canceling position in which it engages with the external teeth of the latch ring and allows the car sensor lever to be displaced to the second operating position; and a first disk that rotates at a speed slower than the spindle in response to rotation of the spindle, the first disk having a first contact portion on its outer periphery that contacts the switch lever to displace the switch lever to the lock canceling position, the first contact portion being displaced via the first disk by rotation of the spindle in a first rotational direction in response to retraction of the seat belt and rotation of the spindle in a second rotational direction opposite to the first rotational direction in response to withdrawal of the seat belt, displacing the switch lever to the lock canceling position when the amount of withdrawal of the seat belt is maximum.

[0010] According to this embodiment, when the seat belt is withdrawn to a maximum extent, the first contact portion of the first disk comes into contact with the switch lever. This causes the switch lever to be displaced to a position that restricts the operation of the CS / WS lock (i.e., the lock canceling position). As a result, the seat belt retractor according to the present disclosure can prevent an inadvertent lock-up from occurring when the seat belt is withdrawn to a maximum extent. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is an exploded three-dimensional view of a seat belt retractor 1. [Diagram 2] 2 is a diagram showing the configuration of a WS assembly 20. FIG. [Diagram 3] 3A to 3C are diagrams showing the configuration of a latch ring 24. [Figure 4] 11A to 11C are diagrams illustrating the operation of the WS lever 22. [Diagram 5] 3A to 3C are diagrams showing the configuration of a bearing plate 30. [Figure 6] 2 is a diagram showing the configuration of a cam disc 50. FIG. [Figure 7] 5 is a diagram for explaining the second contact portion 56 of the cam disc 50 in detail. FIG. [Figure 8] 3A to 3C are diagrams showing the configuration of a friction plate 60. [Figure 9] 3A and 3B are diagrams illustrating a configuration of a wobble gear 80. [Figure 10] 1A and 1B are diagrams showing the configuration of the front side of a hub 90. [Figure 11] 13 is a diagram showing the configuration of the back side of the hub 90. FIG. [Figure 12] 1 is a diagram showing the configuration of a CS assembly 35. FIG. [Figure 13] 13 is a diagram showing the configuration of the front side of the SW lever 70. FIG. [Figure 14] 13 is a diagram showing the configuration of the back side of the SW lever 70. FIG. [Figure 15] 2A to 2C are diagrams showing the configuration of a friction lever 110. [Figure 16]3A to 3C are diagrams showing the configuration of an ALR lever 40. [Figure 17] 11A to 11C are diagrams for explaining the operations of the hub 90, the wobble gear, and the cam disc 50 caused by winding and unwinding the seat belt. [Figure 18] FIG. 13 is a diagram showing the positional relationship of each member when WS / CS / ALR lock canceling is not activated. [Figure 19] FIG. 13 is a diagram showing the positional relationship of each member during operation of WS / CS / ALR lock canceling. [Figure 20] 11 is a diagram showing the positional relationship between the SW lever 70, the CS lever 37, the latch ring 24, and the steering disc 21 when the WS / CS lock canceling is activated. FIG. [Figure 21] 11 is a diagram showing the positional relationship between the SW lever 70, the latch ring 24, and the steering disc 21 when the WS lock canceling is activated. FIG. [Figure 22] 10 is a diagram showing the positional relationship between the ALR lever 40, the friction plate 60, and the steering disc 21 when the ALR lock canceling is activated. FIG. [Diagram 23] FIG. 4 is a diagram showing the amount of seat belt withdrawal at each point in time. [Figure 24] FIG. 13 is a diagram for explaining that the WS / CS / ALR lock canceling is activated when the seat belt withdrawal amount is equal to or greater than a second withdrawal amount. [Diagram 25] FIG. 13 is a diagram for explaining that the WS / CS / ALR lock becomes operable when the seat belt is wound up so that the seat belt withdrawal amount is equal to or less than the second withdrawal amount and equal to or greater than the first withdrawal amount. [Figure 26] FIG. 13 is a diagram for explaining that the WS / CS / ALR lock becomes operable when the seat belt is wound up so that the seat belt withdrawal amount is equal to or less than the second withdrawal amount and equal to or greater than the first withdrawal amount. [Figure 27]FIG. 13 is a diagram for explaining that the WS / CS / ALR lock canceling is activated when the seat belt is wound up so that the seat belt withdrawal amount becomes equal to or less than a first withdrawal amount. [Figure 28] FIG. 13 is a diagram explaining that when the seat belt is pulled out so that the amount of the seat belt pulled out becomes equal to or less than a second amount and equal to or more than a first amount, the WS / CS lock becomes operable and the ALR lock canceling is activated. [Figure 29] FIG. 13 is a diagram explaining that when the seat belt is pulled out so that the amount of the seat belt pulled out becomes equal to or less than a second amount and equal to or more than a first amount, the WS / CS lock becomes operable and the ALR lock canceling is activated. [Diagram 30] FIG. 13 is a diagram for explaining that the WS / CS / ALR lock canceling is activated when the seat belt is pulled out to a second pulled-out amount or more. [Diagram 31] 1 is a diagram showing a seat belt retractor 1 equipped with a SW lever return spring 115 instead of the friction lever 110. FIG.

[0012] A preferred embodiment of the present disclosure will be described with reference to the accompanying drawings. In this specification, up / down, left / right, and front / rear are defined as follows. When an occupant sits on a vehicle seat in a normal position, the direction in which the occupant faces forward is called the front, and the opposite direction is called the rear. Similarly, left / right and up / down are based on the case in which the occupant sits on a vehicle seat in a normal position. Clockwise and counterclockwise refer to the directions of rotation in each drawing.

[0013] In this disclosure, "WS", "CS" and "SW" are abbreviations for "webbing sensor", "car sensor" and "switch", respectively. For example, "SW lever" is synonymous with "switch lever".

[0014] In addition, in this disclosure, the terms "WS lock", "CS lock" and "ALR lock" respectively refer to functions or mechanisms that prevent the seat belt from being withdrawn by the WS / CS / ALR.

[0015] In addition, in this disclosure, "WS lock canceling", "CS lock canceling", and "ALR lock canceling" respectively refer to functions or mechanisms that limit the activation of the WS lock / CS lock / ALR lock.

[0016] <1. Seatbelt retractor configuration> (Overall configuration of seat belt retractor 1) First, the main configuration of a seat belt retractor 1 will be described with reference to FIG.

[0017] The seat belt retractor 1 comprises a metal spindle 12 around which a seat belt (not shown) is wound, a spring-type winding device 11 that rotates and biases the spindle 12 in the winding direction, a metal frame 10 that rotatably supports the spindle 12, a bearing plate 30 fixed to the frame 10, a latch ring 24 rotatably arranged on the bearing plate 30, a WS assembly 20 supported on the spindle 12 so as to rotate integrally therewith, a CS assembly 35 arranged on the bearing plate 30, an ALR lever 40 and a SW lever 70 rotatably supported on the bearing plate 30, a cam disc 50 that rotates in response to the rotation of the spindle 12, a friction plate 60 that rotates in response to the rotation of the cam disc 50, and a cover member 120 fixed to the frame 10 so as to cover the bearing plate 30. The seat belt retractor 1 further includes an ALR lever return spring 48 , a wobble gear 80 , a hub 90 , a clamping spring 100 and a friction lever 110 .

[0018] In the seat belt retractor 1, the spindle 12, the latch ring 24, the WS assembly 20, the cam disc 50, the friction plate 60, the wobble gear 80, and the hub 90 are all arranged coaxially. That is, these members all rotate about a common rotation axis with the spindle 12.

[0019] In this disclosure, the spindle 12 rotates clockwise when retracting the seat belt and counterclockwise when unretracting the seat belt.

[0020] (Frame 10) The frame 10 has left and right side plates 13, 14 facing each other across the axial center of the spindle 12, with a locking mechanism (comprised of the WS assembly 20, CS assembly 35, ALR lever 40, latch ring 24, etc.) that physically locks the withdrawal of the seat belt disposed on the outside of one of the side plates 14, and the retractor 11 disposed on the outside of the other side plate 13. A shaft 15 on one end side of the spindle 12 passes through the WS assembly 20, latch ring 24, bearing plate 30, friction plate 60, cam disc 50, and wobble gear 80, and a hub 90 is fixed to its tip so as to rotate integrally therewith.

[0021] (WS assembly 20, latch ring 24) Fig. 2 is a diagram showing an example of the configuration of the WS assembly 20. The WS assembly 20 has a steering disc 21 and a WS lever 22. Fig. 3 is a diagram showing an example of the configuration of the latch ring 24. The latch ring 24 has external teeth 25 on its outer circumferential surface side and internal teeth 26 on its inner circumferential surface side.

[0022] The steering disc 21 has an axial hole 29, external teeth 23 formed on the outer peripheral surface, and a convex shaft 28 that fits into the axial hole of the WS lever 22 and supports the WS lever 22 so as to be able to swing. The axial hole 29 is penetrated by the shaft 15 of the spindle 12. This allows the steering disc 21 to be supported by the spindle 12 so as to be able to rotate integrally with the spindle 12. That is, when the spindle 12 rotates, the steering disc 21 rotates at the same rotation speed as the spindle 12. On the other hand, when the rotation of the spindle 12 stops, the rotation of the steering disc 21 also stops. Similarly, when the rotation of the steering disc 21 stops, the rotation of the spindle 12 also stops. The WS / CS / ALR lock of the present disclosure prevents the rotation of the spindle 12 by preventing the rotation of the steering disc 21.

[0023] The WS lever 22 has a latch ring engagement claw 27 at one end in the outer diameter direction that can engage with the internal teeth 26 of the latch ring 24. In a normal state, as shown in Fig. 4(A), the WS lever 22 is in a WS non-engagement position where the latch ring engagement claw 27 does not engage with the internal teeth 26 of the latch ring 24. In contrast, when a predetermined or greater angular acceleration is applied to the WS assembly 20 (for example, when the spindle 12 rotates at high speed by withdrawing the seat belt at high speed), the WS lever 22 is displaced to the WS engagement position where the latch ring engagement claw 27 engages with the internal teeth 26 of the latch ring 24, as shown in Fig. 4(B).

[0024] When the WS lever 22 is in the WS engagement position, the steering disc 21 and the latch ring 24 rotate together. That is, when the steering disc 21 rotates, the latch ring 24 rotates at the same rotational speed as the steering disc 21, and when the rotation of the latch ring 24 stops, the rotation of the steering disc 21 also stops. On the other hand, when the WS lever 22 is in the WS disengagement position, the latch ring 24 and the steering disc 21 are each independently rotatable. That is, even if the rotation of the latch ring 24 stops, the steering disc 21 can rotate.

[0025] (Bearing plate 30) 5 is a diagram showing an example of the configuration of the bearing plate 30. The bearing plate 30 is disposed on the frame 10 so as to cover the WS assembly 20 and the latch ring 24. The bearing plate 30 has a peripheral wall portion 31, an ALR lever rotation shaft 32, a SW lever rotation shaft 33, and a CS assembly fitting portion 34.

[0026] The peripheral wall portion 31 is formed so as to have a convex shape extending from the bearing plate 30 in the positive direction of the z-axis. A shaft hole 301 through which the shaft 15 of the spindle 12 passes is formed in the center of the peripheral wall portion 31. A gear receiving portion 300 with which the gear body 81 of the wobble gear 80 engages is provided on the inner circumferential surface of the peripheral wall portion 31.

[0027] The ALR lever rotating shaft 32 is inserted into the cylindrical portion 41 of the ALR lever 40. The SW lever rotating shaft 33 is inserted into the cylindrical portion 73 of the SW lever 70. A housing 36 of a CS assembly 35 is fitted into the CS assembly fitting portion 34.

[0028] (CamDisc 50) 6 is a diagram showing an example of the configuration of the cam disc 50. The cam disc 50 is disposed so that its inner peripheral surface contacts the outer peripheral surface of the peripheral wall portion 31 of the bearing plate 30. The cam disc 50 has a first operating region 51, a first non-operating region 52, a transition portion 53, a first contact portion 54, a second contact portion 56, and a groove portion 55.

[0029] The first operating area 51 and the first non-operating area 52 are both part of the outer periphery of the cam disc 50. The first operating area 51 is thicker in the outer diameter direction than the first non-operating area 52. The second contact portion 56 and the groove portion 55 are provided in the first operating area 51. The groove portion 55 engages with a cam disc engaging claw portion 83 of the wobble gear 80.

[0030] The first operating region 51 is an area used for WS / CS lock canceling, and the first non-operating region 52 is an area used for preventing WS / CS lock canceling. The transition portion 53 is a switching cam for smoothly transitioning between the first operating region 51 and the first non-operating region 52. Therefore, for example, in a portion of the transition portion 53 close to the first operating region 51, the WS / CS lock canceling is in an operable state. In other words, it can be said that at least most of the transition portion 53 is included in the first non-operating region 52. The first contact portion 54 is provided on the outer periphery of the cam disc 50 between the first operating region 51 and the first non-operating region 52. The transition portion 53 is shaped like a slope that rises gently from the first non-operating region 52 toward the first operating region 51. On the other hand, the first contact portion 54 is shaped like a mountain that rises steeply from the first non-operating region 52 toward the first operating region 51. The length of the first contact portion 54 in the outer radial direction is greater than the thickness of the first operating region 51 in the outer radial direction.

[0031] 7 is a diagram for explaining in detail the second contact portion 56 of the cam disc 50. The second contact portion 56 protrudes radially outward from the outer periphery of the first operating region 51. The second contact portion 56 has a pressing portion 57 formed on one side closer to the transition portion 53 in the circumferential direction, and a pressing portion 58 formed on the other side closer to the first contact portion 54 in the circumferential direction.

[0032] (Friction plate 60) 8 is a diagram showing an example of the configuration of the friction plate 60. The friction plate 60 is disposed between the bearing plate 30 and the cam disc 50 such that the inner peripheral surface of the friction plate 60 contacts the outer peripheral surface of the peripheral wall portion 31 of the bearing plate 30. The friction plate 60 has a second operating region 61, a second non-operating region 62, pressed portions 63 and 65, and a switching cam 64.

[0033] The second operating region 61 and the second non-operating region 62 are both part of the outer periphery of the friction plate 60. The second operating region 61 is thicker than the second non-operating region 62 in the outer diameter direction.

[0034] The second operating region 61 is a region where the ALR lock canceling is activated by contacting the ALR lever 40 described later, and the second non-operating region 62 is a region where the ALR lock canceling is not activated. The switching cam 64 is a switching cam for smoothly transitioning between the second operating region 61 and the second non-operating region 62. Therefore, when the ALR lever 40 is in contact with the friction plate 60 at a portion of the switching cam 64 close to the second non-operating region 62, for example, the operation of the ALR lock canceling is restricted. In other words, at least a part of the switching cam 64 is included in the second non-operating region 62. The pressed portions 63 and 65 are provided between the second operating region 61 and the second non-operating region 62. The pressed portion 63 is pressed by the pressing portion 57 in response to the rotation of the cam disc 50. The pressed portion 65 is pressed by the pressing portion 58 in response to the rotation of the cam disc 50.

[0035] (Wobble Gear 80) FIG. 9 is a diagram showing an example of the configuration of the wobble gear 80. The wobble gear 80 has a gear body 81, a hole 82 provided at the center of the gear body 81, and a cam disc engagement claw 83. The gear body 81 is disposed on the inner peripheral surface side of the peripheral wall portion 31 of the bearing plate 30. As a result, the gear body 81 engages with the gear receiving portion 300 on the inner wall surface side of the peripheral wall portion 31. The number of teeth of the gear body 81 is smaller than the number of teeth of the gear receiving portion 300. For example, the number of teeth of the gear body 81 is "19" in FIG. 9, whereas the number of teeth of the gear receiving portion 300 is "20" in FIG. An eccentric portion 92 of a hub 90, which will be described later, is fitted into the hole 82. The cam disc engagement claw 83 extends from the gear body 81 and engages with a groove portion 55 of the cam disc 50.

[0036] (Hub 90) 10 and 11 are diagrams showing an example of the configuration of the hub 90. Specifically, FIG. 10 is a three-dimensional view of the hub 90 seen from the front side (i.e., the z-axis positive direction), and FIG. 11 is a plan view of the hub 90 seen from the back side (i.e., the z-axis negative direction). The hub 90 has a friction lever sliding groove portion 91, an eccentric portion 92, and a rotating shaft 93. The friction lever sliding groove portion 91 is formed in a substantially cylindrical peripheral surface portion that protrudes slightly from the front end face of the hub 90. The eccentric portion 92 is formed as a cylindrical portion that protrudes slightly from the back end face of the hub 90, and the center of the cylindrical portion is eccentric with respect to the center of the hub 90.

[0037] The eccentric portion 92 is disposed on the inner peripheral surface side of the hole portion 82 of the wobble gear 80. As a result, the outer peripheral surface of the eccentric portion 92 is slidable against the inner peripheral surface of the hole portion 82. The rotating shaft 93 is provided at the center with respect to the hub 90. On the other hand, the rotating shaft 93 is provided at an eccentric position with respect to the eccentric portion 92. The shaft 15 of the spindle 12 is fixed to the rotating shaft 93, and the rotating shaft 93 rotates at the same rotation speed and in the same direction as the spindle 12. In other words, when the spindle 12 rotates, the hub 90 as a whole simply rotates about the rotating shaft 93, while the eccentric portion 92 rotates eccentrically in response to the rotation of the rotating shaft 93. A base portion 111 of a friction lever 110 is fitted into the friction lever sliding groove portion 91.

[0038] (CS Assembly 35) 12 is a diagram showing an example of the configuration of the CS assembly 35. The CS assembly 35 has a housing 36, a CS lever 37, and an inertial body 38. The housing 36 is disposed in the CS assembly fitting portion 34 of the bearing plate 30. The CS lever 37 has an axis that fits into an axis hole 39 of the housing 36. This allows the CS lever 37 to be pivotally supported by the housing 36 so as to be able to swing freely. The inertial body 38 is able to swing freely in the space inside the housing 36. The inertial body 38 is, for example, a sphere.

[0039] The back side of the CS lever 37 (i.e., the surface facing the negative y-axis direction) has a recess, and in the normal state, the inertial body 38 fits into this recess. This keeps the CS lever 37 in a relatively low position. When the CS lever 37 is in this position, the CS lever 37 does not engage with the external teeth 23 of the steering disc 21. In other words, operation of the CS lock is limited. Therefore, the relatively low position to which the CS lever 37 can be displaced can also be called the CS lock non-operating position.

[0040] On the other hand, for example, when a large acceleration acts on the vehicle to which the seat belt retractor 1 is attached (for example, when the vehicle brakes suddenly), the inertial body 38 is displaced in the space inside the housing 36. This causes the inertial body 38 to come out of the recess on the back side of the CS lever 37. As a result, the CS lever 37 swings and displaces to a relatively high position. When the CS lever 37 is in this position, the CS lever 37 engages with the external teeth 23 of the steering disc 21. That is, the CS lock is activated. Therefore, the relatively high position to which the CS lever 37 can be displaced can also be called the CS lock activation position.

[0041] (SW lever 70) 13 and 14 are diagrams showing an example of the configuration of the SW lever 70. Specifically, Fig. 13 is a three-dimensional view of the SW lever 70 seen from the front side (i.e., the z-axis positive direction), and Fig. 14 is a three-dimensional view of the SW lever 70 seen from the back side (i.e., the z-axis negative direction). The SW lever 70 has a cylindrical portion 73, a friction lever engagement projection 72, a cam disc engagement projection 71, a CS lock canceling projection 75, and a WS lock projection 74.

[0042] The SW lever rotating shaft 33 of the bearing plate 30 is inserted into the cylindrical portion 73. As a result, the SW lever 70 is rotatably supported by the bearing plate 30. The friction lever engaging projection 72 engages with the SW lever engaging groove 112 of the friction lever 110. The cam disc engaging projection 71 contacts the outer circumferential surface of the cam disc 50 (including the first operating area 51 and the first non-operating area 52). In other words, the cam disc engaging projection 71 is a cam follower guided by the outer circumferential surface of the cam disc 50, and functions as a portion to which power for swinging the SW lever 70 is input. The CS lock canceling projection 75 is configured to be capable of coming into contact with and being separated from the CS lever 37. The WS lock projection 74 is configured to be capable of being engaged with and disengaged from the external teeth 25 of the latch ring 24.

[0043] (Friction Lever 110) 15 is a diagram showing an example of the configuration of the friction lever 110. The friction lever 110 is configured to be able to rotate together with the spindle 12 as the spindle 12 rotates. The friction lever 110 has a substantially C-shaped base 111, a mounting portion 113 formed on the outer periphery of the base 111 and on which the clamping spring 100 is mounted, a sliding portion 114 formed on the inner periphery of the base 111 and slidably coupled (engaged) with the friction lever sliding groove portion 91 of the hub 90, and a SW lever engagement groove 112 formed to protrude outward in the outer diameter direction from the outer periphery of the base 111 and engaged with the friction lever engagement protrusion 72 of the SW lever 70.

[0044] The base 111 has a notch groove extending in the outer diameter direction formed on the opposite side of the notch in the substantially C-shape. This allows the base 111 to be elastically deformed (reduced in diameter) in the outer diameter direction. The base 111 is reduced in diameter by the elastic force of the clamping spring 100 attached to the attachment portion 113, and the sliding portion 114 and the friction lever sliding groove portion 91 of the hub 90 are thereby coupled by friction force. The magnitude of this friction force is approximately proportional to the elastic force of the clamping spring 100. That is, since the friction lever 110 rotates due to the friction force between the friction lever 110 and the hub 90, when a rotational torque exceeding this friction force acts on the friction lever 110 (for example, when the hub 90 tries to rotate in a state where the friction lever 110 is fixed), the hub 90 can rotate independently of the friction lever 110 while sliding against the sliding portion 114 of the friction lever 110 at the friction lever sliding groove portion 91.

[0045] (ALR lever 40) 16 is a diagram showing an example of the configuration of the ALR lever 40. The ALR lever 40 has a cylindrical portion 41 into which the ALR lever rotating shaft 32 of the bearing plate 30 is inserted, an ALR control cam 43 that contacts the friction plate 60, and an ALR engagement claw portion 42 that engages with the external teeth 23 of the steering disc 21 when the ALR lock is activated. The ALR lever 40 is axially supported by the ALR lever rotating shaft 32 of the bearing plate 30 so as to be freely rotatable.

[0046] <2. Operation of seat belt retractor 1> (Rotation of cam disc 50 by pulling / retracting the seat belt) In the seatbelt retractor 1, the spindle 12 and the cam disc 50 rotate in opposite directions. The sequence of operations will be described with reference to Figures 17(A)-(C). In the following description, the directions in the xy plane with the rotation axis 93 as the origin will be explained using an analog clock as an example. Specifically, the positive and negative directions of the x-axis correspond to the "3 o'clock direction" and the "9 o'clock direction", respectively. Moreover, the positive and negative directions of the y-axis correspond to the "12 o'clock direction" and the "6 o'clock direction", respectively.

[0047] 17(A) shows the positional relationship between the hub 90 (including the rotating shaft 93 and the eccentric portion 92), the wobble gear 80 (including the gear body 81 and the cam disc engaging claw portion 83), and the cam disc 50 (including the groove portion 55) when the seat belt is pulled out at a maximum amount. In this state, the eccentric portion 92 is eccentric in the 3 o'clock direction when viewed from the rotating shaft 93. Also, the cam disc engaging claw portion 83 of the wobble gear 80 engages with the groove portion 55 of the cam disc 50 in the 3 o'clock direction.

[0048] FIG. 17(B) shows the positional relationship of each member when the seat belt is wound up from the situation of FIG. 17(A). When the seat belt is wound up, the spindle 12 rotates in the clockwise direction, so that the eccentric portion 92 rotates in the clockwise direction around the eccentric rotation shaft 93. At this time, the outer peripheral surface of the eccentric portion 92 presses the gear body 81 in the 6 o'clock to 7 o'clock direction from the inner peripheral surface side of the hole portion 82 (FIG. 17(B)(1)). As a result, the gear body 81 and the gear receiving portion 300 of the peripheral wall portion 31 engage with each other in the 3 o'clock to 4 o'clock direction (FIG. 17(B)(2)), and the gear body 81 rotates in the counterclockwise direction while the outer peripheral surface of the eccentric portion 92 and the inner peripheral surface of the hole portion 82 slide against each other (FIG. 17(B)(3)). As a result, the cam disc engaging claw portion 83 of the wobble gear 80 engaged with the groove portion 55 rotates the cam disc 50 in the counterclockwise direction.

[0049] FIG. 17(C) shows the positional relationship of each member when the seat belt is further wound up from the state of FIG. 17(B). In response to the winding of the seat belt, the eccentric portion 92 rotates in a clockwise direction around the eccentric rotating shaft 93. At this time, the outer peripheral surface of the eccentric portion 92 presses the inner peripheral surface of the hole portion 82 of the gear body 81 in the 8 o'clock to 9 o'clock direction (FIG. 17(C)(1)). As a result, the gear body 81 and the gear receiving portion 300 of the peripheral wall portion 31 engage with each other in the 5 o'clock to 6 o'clock direction (FIG. 17(C)(2)), and the gear body 81 rotates in a counterclockwise direction (FIG. 17(C)(3)). As a result, the cam disc engaging claw portion 83 engaged with the groove portion 55 rotates the cam disc 50 further in the counterclockwise direction.

[0050] In summary, when the spindle 12 rotates clockwise by winding up the seat belt, the cam disc 50 rotates counterclockwise. On the other hand, when the seat belt is withdrawn, the spindle 12 rotates counterclockwise and the cam disc 50 rotates clockwise.

[0051] (Lock canceling mechanism) [Lock canceling position and ALR inoperative position] First, the relationship between the positions of the SW lever 70 and the ALR lever 40 and the WS / CS / ALR lock canceling will be described with reference to FIGS. 18 and 19.

[0052] Fig. 18 is a diagram showing the positional relationship of each member when WS / CS / ALR lock canceling is not activated (i.e., when all of the WS lock, CS lock, and ALR lock can be activated). In Fig. 18, the SW lever 70 is displaced to a non-lock canceling position that does not activate the WS / CS lock canceling (i.e., activates the WS / CS lock) by the action of the friction lever 110 (described later). Also, in Fig. 18, the ALR lever 40 is displaced to an ALR activated position that activates the ALR by the action of the ALR lever return spring 48 (described later).

[0053] FIG. 19 is a diagram showing the positional relationship of each member when the WS / CS / ALR lock canceling is activated (i.e., when the activation of all of the WS lock, CS lock, and ALR lock is restricted). In FIG. 19, the first operating region 51 of the cam disc 50 presses the cam disc engagement protrusion 71 of the SW lever 70 in the 6 o'clock direction. As a result, the SW lever 70 is biased in the counterclockwise direction around the cylindrical portion 73, and is displaced to the lock canceling position where the WS / CS lock canceling is activated. Note that, although FIG. 19 shows a state in which the first operating region 51 of the cam disc 50 displaces the SW lever 70 to the lock canceling position, the SW lever 70 is also displaced to the lock canceling position by the first contact portion 54 of the cam disc 50 pressing the cam disc engagement protrusion 71 of the SW lever 70 (see FIG. 24 described later).

[0054] Also, in Fig. 19, the second operating region 61 of the friction plate 60 presses the ALR control cam 43 of the ALR lever 40 in the 4 o'clock to 5 o'clock direction. As a result, the ALR lever 40 is urged in the counterclockwise direction around the cylindrical portion 41 and displaced to the ALR inoperative position where operation of the ALR lock is restricted. Note that, although Fig. 19 shows a state in which the second operating region 61 of the friction plate 60 displaces the ALR lever 40 to the ALR inoperative position, the ALR lever 40 is also displaced to the ALR inoperative position by the second contact portion 56 of the cam disc 50 pressing the ALR control cam 43 of the ALR lever 40 (see Fig. 24 described later).

[0055] The reason why the operation of the WS / CS lock is restricted when the SW lever 70 is in the lock canceling position, and the reason why the ALR lock does not operate when the ALR lever 40 is in the ARL inoperation position will be described below.

[0056] [CS lock canceling mechanism] The reason why the operation of the CS lock is restricted when the SW lever 70 is in the lock canceling position will be described with reference to Figures 20(A) and (B). Figures 20(A) and (B) focus on the area AR1 in Figures 18 and 19, respectively.

[0057] Fig. 20(A) is a diagram showing a state in which the SW lever 70 is in the non-lock canceling position and the CS lock is activated. In Fig. 20(A), the inertial body 38 displaces the CS lever 37 to the CS lock position. This allows the CS lever 37 to engage with the external teeth 23 of the steering disc 21. As a result, the counterclockwise rotation of the steering disc 21 (i.e., the rotation when withdrawing the seat belt) is prevented.

[0058] On the other hand, FIG. 20(B) is a diagram showing a situation in which the operation of the WS / CS lock is restricted because the SW lever 70 is in the lock canceling position. As shown in FIG. 20(B), when the SW lever 70 is in the lock canceling position, the CS lock canceling protrusion 75 of the SW lever 70 presses the CS lever 37 in the 6 o'clock direction. As a result, even if a large acceleration acts on the CS assembly 35, the inertial body 38 is prevented from coming off the recess on the back side of the CS lever 37 due to the pressure on the CS lever 37. That is, the CS lock canceling protrusion 75 prevents the CS lever 37 from being displaced to the CS lock operating position. When the CS lever 37 is not in the CS lock operating position, the CS lever 37 and the external teeth 23 of the steering disc 21 are not engaged with each other. Therefore, the operation of the CS lock is restricted.

[0059] As described above, when the SW lever 70 is in the non-lock canceling position, the engagement between the CS lever 37 and the external teeth 23 of the steering disc 21 is not prevented, and the CS lock can be activated (see FIG. 20(A)). On the other hand, when the SW lever 70 is in the lock canceling position, the CS lock canceling protrusion 75 prevents the engagement between the CS lever 37 and the external teeth 23 of the steering disc 21, and activation of the CS lock is restricted (see FIG. 20(B)).

[0060] [WS lock canceling mechanism] 21 and 20(B), the reason why the operation of the WS lock is restricted when the SW lever 70 is in the lock canceling position will be described. FIG 21 is a diagram focusing on the area AR1 in FIG 18.

[0061] Fig. 21 is a diagram showing a state in which the SW lever 70 is in the non-lock canceling position and the WS lock is operable. As shown in Fig. 21, when the SW lever 70 is in the non-lock canceling position, the WS lock protrusion 74 is displaced to a position where it can engage with the external teeth 25 of the latch ring 24. At this time, when the WS lever 22 is displaced from the WS non-engagement position to the WS engagement position (i.e., when the steering disc 21 and the latch ring 24 are in a state in which they rotate together), the counterclockwise rotation of the steering disc 21 is prevented by the latch ring 24 engaged with the SW lever 70.

[0062] On the other hand, according to Fig. 20(B), when the SW lever 70 is in the lock canceling position, the WS lock protrusion 74 does not engage with the external teeth 25 of the latch ring 24. In other words, when the SW lever 70 is in the lock canceling position, even if the WS lever 22 is displaced to the WS engagement position (see Fig. 4(B)), the rotation of the latch ring 24 is not prevented by the SW lever 70, and therefore the rotation of the steering disc 21 (i.e., the rotation of the spindle 12) is similarly not prevented.

[0063] As described above, when the SW lever 70 is in the non-lock canceling position, rotation of the latch ring 24 is prevented, and the WS lock is operable (see FIG. 21). On the other hand, when the SW lever 70 is in the lock canceling position, even if the WS lever 22 is displaced to the WS engagement position, rotation of the latch ring 24 is not prevented, and operation of the WS lock is restricted (see FIG. 20(B)).

[0064] [ALR lock canceling mechanism] The reason why the operation of the ALR lock is restricted when the ALR lever 40 is in the ALR inoperative position will be described with reference to Figures 22(A) and (B). Figures 22(A) and (B) are diagrams focusing on the area AR2 in Figures 18 and 19, respectively.

[0065] 22(A) is a diagram showing a state in which the ALR lever 40 is in the ALR operating position and the ALR lock is operable. The ALR engagement claw portion 42 of the ALR lever 40 is wound around the cylindrical portion 41, and is biased in the clockwise direction by the elastic force of the ALR lever return spring 48, one end of which is supported by the bearing plate 30. This displaces the ALR engagement claw portion 42 to a position where it can engage with the external teeth 23 of the steering disc 21. As a result, the counterclockwise rotation of the steering disc 21 (i.e., the rotation when withdrawing the seat belt) is prevented. At this time, the ALR control cam 43 of the ALR lever 40 is in contact with the switching cam 64 (part of the second non-operating region 62) of the friction plate 60.

[0066] 22(B) is a diagram showing a situation in which the ALR lever 40 is in the ALR inoperative position and the operation of the ALR lock is restricted. The ALR control cam 43 of the ALR lever 40 is pressed by the second operating region 61 of the friction plate 60 with a force stronger than the elastic force of the ALR lever return spring 48. As a result, the ALR engagement claw portion 42 of the ALR lever 40 is displaced to a position where it does not engage with the external teeth 23 of the steering disc 21. In this case, the counterclockwise rotation of the steering disc 21 (i.e., the rotation when withdrawing the seat belt) is not prevented, and the rotation of the spindle 12 is likewise not prevented.

[0067] As described above, when the ALR lever 40 is in the ALR operating position, the ALR lock can be activated because the engagement between the ALR engagement claw 42 and the external teeth 23 of the steering disc 21 is not prevented (see FIG. 20(A)). On the other hand, when the ALR lever 40 is in the ALR non-operating position, the engagement between the ALR engagement claw 42 and the external teeth 23 of the steering disc 21 is prevented, so activation of the ALR lock is restricted (see FIG. 22(B)).

[0068] (Relationship between seat belt extension amount and lock canceling) The relationship between the amount of seat belt withdrawal and lock canceling will be described with reference to Figures 23-30.

[0069] FIG. 23 is a diagram showing the amount of withdrawal of the seat belt at each time point. Time point A is the time point when the amount of withdrawal of the seat belt is equal to or more than the second amount of withdrawal (almost the maximum). Time points B and C are the times when the seat belt is wound from time point A, and the amount of withdrawal is equal to or less than the second amount of withdrawal and equal to or more than the first amount of withdrawal. Time point D is the time point when the seat belt is further wound from time point C, and the amount of withdrawal is equal to or less than the first amount of withdrawal. Time points E and F are the times when the seat belt is pulled out from time point D, and the amount of withdrawal is equal to or more than the first amount of withdrawal and equal to or less than the second amount of withdrawal. Time point G is the time point when the seat belt is pulled out from time point F, and the amount of withdrawal is equal to or more than the second amount of withdrawal (almost the maximum). In the present disclosure, the "almost the maximum amount of withdrawal" may be, for example, about 90% to 99% of the upper limit of the amount of withdrawal (i.e., the maximum amount of withdrawal) when the seat belt is pulled out in a normal manner.

[0070] 24-27 are diagrams showing the operation of the seat belt retractor 1 from time A until the seat belt is wound up to time D. In contrast, FIGS. 28-30 are diagrams showing the operation of the seat belt retractor 1 from time D until the seat belt is withdrawn to time G.

[0071] [Point A] Fig. 24 is a diagram showing the state of the seat belt retractor 1 at time point A (the time point when the seat belt withdrawal amount is equal to or greater than the second withdrawal amount). As shown in Fig. 24, at time point A, the first contact portion 54 of the cam disc 50 is in contact with the cam disc engagement protrusion 71 of the SW lever 70. As a result, the SW lever 70 is oriented counterclockwise around the cylindrical portion 73 and displaced to the lock canceling position. As described with reference to Figs. 20-21, when the SW lever 70 is in the lock canceling position, the operation of the WS / CS lock is restricted.

[0072] Furthermore, at time point A, the second contact portion 56 of the cam disc 50 is in contact with the ALR control cam 43 of the ALR lever 40. As a result, the ALR lever 40 is oriented counterclockwise around the cylindrical portion 41 and displaced to the ALR inoperative position. As described with reference to Figure 22, when the ALR lever 40 is in the ALR inoperative position, operation of the ALR lock is restricted.

[0073] As described above, the seat belt retractor 1 activates the WS / CS / ALR lock canceling at time A when the seat belt is withdrawn to a substantially maximum extent. That is, at time A, the activation of all of the WS / CS / ALR locks is restricted.

[0074] [Times B and C] Fig. 25 is a diagram showing the state of the seat belt retractor 1 at time B (the time when the seat belt withdrawal amount is equal to or less than the second withdrawal amount and equal to or more than the first withdrawal amount). By winding up the seat belt, the hub 90 rotates in the clockwise direction (Fig. 25(1)). In contrast, as described with reference to Fig. 17, the cam disc 50 rotates in the counterclockwise direction (Fig. 25(2)). As a result, the ALR control cam 43 of the ALR lever 40 is no longer directed toward the second contact portion 56 of the cam disc 50, so that the ALR lever 40 is biased by the ALR lever return spring 48 to rotate clockwise around the cylindrical portion 41 and is displaced to the ALR operating position (Fig. 25(3)).

[0075] Furthermore, due to the clockwise rotation of the hub 90 (FIG. 25(1)), the friction lever 110 coupled to the hub 90 via the sliding portion 114 is biased in the clockwise direction (FIG. 25(4)). As a result, the friction lever 110 biases the SW lever 70 to rotate counterclockwise (i.e., toward the lock canceling position) about the cylindrical portion 73 via the engagement between the SW lever engagement groove 112 and the friction lever engagement protrusion 72 (FIG. 25(5)). However, when the seat belt is withdrawn at time B, the action of the friction lever 110 rotating counterclockwise together with the hub 90 displaces the SW lever 70 to the non-lock canceling position. That is, at time B, the SW lever 70 does not actually activate the WS / CS lock canceling.

[0076] As shown in FIG. 25, when the CS lock canceling projection 75 of the SW lever 70 is in contact with the CS lever 37, the switch lever 70 does not rotate further counterclockwise. Therefore, the clockwise rotation of the friction lever 110 is prevented by the engagement of the switch lever 70 with the friction lever engagement projection 72. In this case, when the hub 90 rotates further clockwise, the hub 90 rotates independently while sliding against the friction lever 110, which cannot rotate further clockwise. This allows the seat belt retractor 1 to rotate independently of the hub 90 while displacing the switch lever 70 to the lock canceling position by the friction lever 110.

[0077] FIG. 26 is a diagram showing the state of the seat belt retractor 1 at time C when the seat belt is further wound up from time B. Further winding of the seat belt causes the hub 90 to rotate in the clockwise direction (FIG. 26(1)). In contrast, the cam disc 50 rotates in the counterclockwise direction (FIG. 26(2)). As a result, the pressing portion 57 provided on one side of the second contact portion 56 of the cam disc 50 presses the pressed portion 63 of the friction plate 60. As a result, the friction plate 60 rotates in the counterclockwise direction together with the cam disc 50, and the switching cam 64 of the friction plate 60 starts to press the ALR control cam 43 of the ALR lever 40. As a result, the ALR lever 40 starts to rotate in the counterclockwise direction around the cylindrical portion 41. Note that at time C, the ALR lever 40 starts to displace toward the ALR non-operating region, but is still in the ALR operating position.

[0078] Furthermore, due to the clockwise rotation of the hub 90 (FIG. 26(1)), the friction lever 110 is biased in the clockwise direction (FIG. 26(4)). This biases the SW lever 70 in the counterclockwise direction (i.e., toward the lock canceling position). However, if the seat belt is withdrawn at time C, the SW lever 70 is displaced to the non-lock canceling position for the same reason as at time B. In other words, even at time C, the SW lever 70 is not actually activating the WS / CS lock canceling.

[0079] As described above, the seatbelt retractor 1 does not activate the WS / CS / ALR lock canceling at time points B and C when the seatbelt is wound up so that its withdrawal amount is equal to or less than the second withdrawal amount and equal to or greater than the first withdrawal amount. In other words, at time points B and C, all of the WS / CS / ALR locks can be activated.

[0080] [Time Point D] 27 is a diagram showing the state of the seat belt retractor 1 at time D (the time when the seat belt withdrawal amount is equal to or less than the first withdrawal amount). Further winding of the seat belt causes the cam disc 50 and the friction plate 60 pressed by the pressing portion 57 of the cam disc 50 to rotate counterclockwise. As a result, the first operating area 51 of the cam disc 50 comes into contact with the cam disc engagement protrusion 71 of the SW lever 70, and the SW lever 70 is directed to the lock canceling position. Furthermore, the counterclockwise rotation of the friction plate 60 causes the second operating area 61 of the friction plate 60 to come into contact with the ALR control cam 43 of the ALR lever 40, and the ALR lever 40 is directed to the ALR inoperative position.

[0081] As described above, the seat belt retractor 1 activates the WS / CS / ALR lock canceling at the time point D when the seat belt withdrawal amount is equal to or less than the first withdrawal amount. That is, at the time point D, the activation of all of the WS / CS / ALR locks is restricted.

[0082] [Times E and F] FIG. 28 is a diagram showing the state of the seat belt retractor 1 at time point E (time point when the withdrawal amount of the seat belt is equal to or larger than the first withdrawal amount and equal to or smaller than the second withdrawal amount). Withdrawal of the seat belt causes the hub 90 to rotate in the counterclockwise direction (FIG. 28(1)). As a result, the cam disc 50 rotates in the clockwise direction (FIG. 28(2)). Meanwhile, the rotation of the hub 90 urges the friction lever 110 in the counterclockwise direction (FIG. 28(3)). As a result, the friction lever 110 urges the SW lever 70 to rotate in the clockwise direction around the cylindrical portion 73 through the engagement between the SW lever engagement groove 112 and the friction lever engagement protrusion 72 (FIG. 28(4)). When the cam disc 50 rotates within the range of the first non-operational region 52 relative to the SW lever 70, the SW lever 70 is displaced to the non-lock canceling position.

[0083] In contrast, at time point E, the friction plate 60 has not rotated as compared to time point D, so the ALR lever continues to be maintained at the ALR inoperative position. This is because the clockwise rotation of the cam disc 50 causes the pressing portion 57 to move in a direction away from the pressed portion 63 of the friction plate 60.

[0084] 28, when the cam disc engagement projection 71 of the SW lever 70 is in contact with the cam disc 50, the switch lever 70 does not rotate further in the clockwise direction. Therefore, the counterclockwise rotation of the friction lever 110 is prevented by the engagement of the switch lever 70 with the friction lever engagement projection 72. In this case, when the hub 90 rotates further in the counterclockwise direction, the hub 90 rotates independently while sliding against the friction lever 110, which cannot rotate further in the counterclockwise direction. This allows the seat belt retractor 1 to rotate independently of the hub 90 while displacing the switch lever 70 to the non-lock canceling position by the friction lever 110.

[0085] FIG. 29 is a diagram showing the state of the seat belt retractor 1 at time F when the seat belt is further withdrawn from time E. By further withdrawing the seat belt, the hub 90 rotates in the counterclockwise direction (FIG. 29(1)), and the cam disc 50 rotates in the clockwise direction (FIG. 29(2)). As a result, the pressing portion 58 provided on one side of the second contact portion 56 of the cam disc 50 starts to press the pressed portion 65 of the friction plate 60. As a result, the friction plate 60 starts to rotate in the clockwise direction. That is, the ALR lever 40 starts to move relatively from the second operating region 61 of the friction plate 60 toward the second non-operating region 62. At time F, the second operating region 61 of the friction plate 60 is in contact with the ALR control cam 43 of the ALR lever 40, so that the ALR lever 40 continues to be maintained in the ALR non-operating position.

[0086] On the other hand, the SW lever 70 is maintained in the non-lock canceling position, similar to the situation in FIG.

[0087] As described above, at time points E and F when the seat belt retractor 1 is pulled out and the amount of the seat belt pulled out is equal to or greater than the first amount and equal to or less than the second amount, the WS / CS lock canceling is not activated, but the ALR lock canceling is activated. In other words, the WS / CS lock is operable, and the ALR lock is restricted from being activated.

[0088] [Point G] Fig. 30 is a diagram showing the state of the seat belt retractor 1 at time G (the time when the seat belt withdrawal amount reaches the second withdrawal amount). By withdrawing the seat belt, the hub 90 rotates in the counterclockwise direction (Fig. 30(1)). As a result, the friction lever 110 rotating together with the hub 90 biases the SW lever 70 in the clockwise direction via the engagement between the SW lever engagement groove 112 and the friction lever engagement protrusion 72. As a result, a moment acts on the SW lever 70 to rotate it in the clockwise direction around the cylindrical portion 73.

[0089] On the other hand, the rotation of the hub 90 causes the cam disc 50 to rotate clockwise (FIG. 30(2)), which causes the first contact portion 54 of the cam disc 50 to press the cam disc engagement protrusion 71 of the SW lever 70. As a result, a moment acts on the SW lever 70 to rotate it counterclockwise around the cylindrical portion 73. Since this moment is greater than the moment that the friction lever 110 acts on the SW lever 70, the SW lever 70 rotates counterclockwise and is displaced to the lock canceling position.

[0090] Furthermore, the counterclockwise rotation of the hub 90 causes the cam disc 50 to rotate clockwise (FIG. 30(2)), which brings the second contact portion 56 of the cam disc 50 into contact with the ALR control cam 43 of the ALR lever 40. This maintains the ALR lever 40 in the ALR inoperative position.

[0091] As described above, at the time point G when the seat belt is withdrawn to the second withdrawn amount or more, the WS / CS / ALR lock canceling is activated in the seat belt retractor 1. In other words, the operation of the WS / CS / ALR lock is restricted.

[0092] In one embodiment, the first pull-out amount can also be said to be the pull-out amount at which the cam disc engagement protrusion 71 of the SW lever 70 contacts the boundary between the first operation area 51 and the first non-operation area 52 of the cam disc 50 when the SW lever 70 is biased clockwise around the cylindrical portion 73. In other words, when winding up the seat belt, the first pull-out amount can also be said to be the pull-out amount at which the cam disc engagement protrusion 71 of the SW lever 70 reaches the top of the "slope" of the transition portion 53 of the cam disc 50. Also, when withdrawing the seat belt, the first pull-out amount can also be said to be the pull-out amount at which the cam disc engagement protrusion 71 of the SW lever 70 begins to descend the "slope" of the transition portion 53 of the cam disc 50.

[0093] In one embodiment, the second pull-out amount can also be said to be the amount of the seat belt pulled out when the second contact portion 56 of the cam disc 50 and the ALR control cam 43 of the ALR lever 40 start to separate (or start to contact). The second pull-out amount can also be said to be the amount of the seat belt pulled out when the first contact portion 54 of the cam disc 50 and the cam disc engaging protrusion 71 of the SW lever 70 start to separate (or start to contact). In other words, after the seat belt is pulled out, when the pull-out amount reaches the second pull-out amount by winding the seat belt, the second contact portion 56 of the cam disc 50 and the ALR control cam 43 of the ALR lever 40 start to separate from the first contact portion 54 of the cam disc 50 and the cam disc engaging protrusion 71 of the SW lever 70 at approximately the same time.

[0094] The above embodiment is merely an example of the present disclosure, and does not limit the contents of the present disclosure.

[0095] <3. Modifications> In the above embodiment, an example in which the SW lever 70 is displaced to the non-lock canceling position by the friction lever 110 has been described. However, the seat belt retractor 1 may include a SW lever return spring 115 that displaces the SW lever 70 to the non-lock canceling position. FIG. 31 is a diagram showing an example of a seat belt retractor 1 that includes a SW lever return spring 115 instead of the friction lever 110. The SW lever 70 in FIG. 31 further includes a return spring engagement protrusion 76. When the cam disc 50 rotates within the range of the first non-operating region 52 relative to the SW lever 70, the SW lever 70 is displaced to the non-lock canceling position by the clockwise moment around the cylindrical portion 73 by the SW lever return spring 115. On the other hand, when the cam disc 50 is rotating within the first operating area 51 relative to the SW lever 70, and when the first contact portion 54 of the cam disc 50 is pressing the SW lever 70, the counterclockwise moment about the cylindrical portion 73 that the first operating area 51 or the first contact portion 54 acts on the SW lever 70 exceeds the clockwise moment due to the SW lever return spring 115, and the SW lever 70 is displaced to the lock canceling position.

[0096] <4. Additional Considerations Regarding Various Embodiments> [Embodiment 1] A spindle 12 that is rotatably supported by the frame 10 and around which a seat belt is wound; A bearing plate 30 fixed to the frame 10; A latch ring 24 having internal teeth 26 and external teeth 25 formed on its inner and outer circumferential surfaces, respectively, and rotatably disposed on a bearing plate 30; a steering disk 21 arranged coaxially with the latch ring 24, having external teeth 23 formed on its outer circumferential surface, and supported by the spindle 12 so as to be integrally rotatable therewith; a webbing sensor lever 22 that is pivotally supported on the steering disc 21 at a position where it can be engaged with and disengaged from the internal teeth 26 of the latch ring 24, and that displaces between a first operating position (WS engagement position) where the steering disc 21 and the latch ring 24 rotate integrally by engaging with the internal teeth 26 of the latch ring 24, and a first non-operating position (WS non-engagement position) where the webbing sensor lever does not engage with the internal teeth 26 of the latch ring 24; a car sensor lever 37 that is pivotally supported by a housing 36 provided on a bearing plate 30 at a position where it can be engaged with and disengaged from the external teeth 23 of the steering disc 21, and that displaces between a second operating position (CS lock operating position) where it engages with the external teeth 23 of the steering disc 21 and a second non-operating position (CS lock non-operating position) where it does not engage with the external teeth 23 of the steering disc 21 in response to an acceleration acting thereon, a switch lever 70 rotatably supported on the bearing plate 30, the switch lever 70 displacing between a lock canceling position where the switch lever 70 does not engage with the external teeth 25 of the latch ring 24 and prevents the car sensor lever 37 from displacing to the second operating position (CS lock operating position) and a non-lock canceling position where the switch lever 70 engages with the external teeth 25 of the latch ring 24 and allows the car sensor lever 37 to displace to the second operating position (CS lock operating position); a first disc (cam disc 50) that rotates at a lower rotational speed than the spindle 12 in response to rotation of the spindle 12, and has a first contact portion 54 on its outer periphery that displaces the switch lever 70 to a lock canceling position by contacting the switch lever 70; Equipped with The first contact portion 54 is displaced via the first disk (cam disk 50) by the rotation of the spindle 12 in a first rotation direction corresponding to the winding of the seat belt and the rotation of the spindle 12 in a second rotation direction opposite to the first rotation direction corresponding to the unwinding of the seat belt, and displaces the switch lever 70 to the lock canceling position when the amount of unwinding of the seat belt is maximum. Seat belt retractor1.

[0097] [Embodiment 2] The first disc (cam disc 50) is a first actuation region 51 for directing the switch lever 70 to a lock canceling position; a first non-operating region 52 on an outer periphery thereof that does not direct the switch lever 70 to the lock canceling position, When the seat belt is withdrawn by a first amount, the seat belt rotates within a first operating range 51 relative to the switch lever 70. When the seat belt withdrawal amount exceeds the first withdrawal amount, the switch lever 70 rotates within the range of the first non-operating region 52. A seat belt retractor 1 according to a first embodiment.

[0098] [Embodiment 3] an ALR lever 40 rotatably supported on the bearing plate 30, the ALR lever 40 being displaceable between a third operating position (ALR operating position) in which rotation of the steering disc 21 in the seat belt withdrawing direction is prevented and a third non-operating position (ALR non-operating position) in which rotation of the steering disc 21 in the seat belt withdrawing direction is not prevented; a second disc (friction plate 60) that is arranged coaxially with the first disc (cam disc 50) and rotates in response to the rotation of the first disc (cam disc 50), the second disc (friction plate 60) having, on its outer periphery, a second operating region 61 that prevents the ALR lever 40 from being displaced to the third operating position (ALR operating position) by contacting the ALR lever 40, and a second non-operating region 62 that allows the ALR lever 40 to be displaced to the third operating position (ALR operating position) even when it comes into contact with the ALR lever 40; Further equipped with The second disk (friction plate 60) is When the seat belt is pulled out from its resting position, The seat belt contacts the ALR lever 40 in the second operating region 61 until the seat belt withdrawal amount reaches a second withdrawal amount that is greater than the first withdrawal amount, When the seat belt is withdrawn by a greater amount than the second amount, the seat belt does not come into contact with the ALR lever 40 in the second operating region 61. When the seat belt is retracted from a state in which it is pulled out more than the second pull-out amount, The seat belt does not come into contact with the ALR lever 40 in the second operating region 61 until the seat belt withdrawal amount returns to the first withdrawal amount. When the seat belt is withdrawn by a first amount or less, the seat belt contacts the ALR lever 40 in the second operating region 61. The seat belt retractor 1 according to the second embodiment.

[0099] [Embodiment 4] The first disc (cam disc 50) further has a second contact portion 56 that comes into contact with the ALR lever 40 when the seat belt withdrawal amount is greater than the second withdrawal amount, The second contact portion 56 comes into contact with the ALR lever 40 to prevent the ALR lever 40 from being displaced to the third operating position (ALR operating position). The seat belt retractor 1 according to the third embodiment.

[0100] [Embodiment 5] The second disc (friction plate 60) is provided between the bearing plate 30 and the first disc (cam disc 50), and has pressed portions 63, 65 between the second non-operating region 62 and the second operating region 61. The second disc (friction plate 60) rotates when the second contact portion 56 of the first disc (cam disc 50) presses against the pressed portions 63, 65. The seat belt retractor 1 according to the fourth embodiment.

[0101] [Embodiment 6] The ALR lever 40 is further provided with a return spring 48 that biases the ALR lever 40 in a direction from the third inoperative position (ALR inoperative position) toward the third operative position (ALR operative position). The seat belt retractor 1 according to the third embodiment.

[0102] [Embodiment 7] The bearing plate 30 further includes a peripheral wall portion 31 having a gear receiving portion 300 provided on an inner peripheral surface thereof. a wobble gear 80 having a gear body 81 that is disposed on the inner peripheral surface side of the peripheral wall portion 31 and is engageable with the gear receiving portion 300, a hole portion 82 provided in the center of the gear body 81, and a claw portion (cam disc engaging claw portion 83) that extends from the gear body 81 and engages with a groove portion 55 provided on the upper surface or lower surface of a first disc (cam disc 50); a hub 90 having an eccentric portion 92 that rotates while sliding on the inner periphery of the hole 82 of the gear body 81 around an eccentric rotating shaft 93 in response to rotation of the spindle 12; When the spindle 12 rotates in a first rotation direction, As the eccentric portion 92 of the hub 90 rotates around the eccentric rotation axis 93 in the first rotation direction, the outer peripheral surface of the eccentric portion 92 of the hub 90 presses the inner peripheral surface of the hole portion 82 of the gear body 81, whereby the gear body 81 engages with the gear receiving portion 300 of the bearing plate 30, the wobble gear 80 rotates in the second rotation direction, and the claw portion (the cam disc engaging claw portion 83) rotates the first disc (the cam disc 50) in the second rotation direction. A seat belt retractor 1 according to a first embodiment.

[0103] [Embodiment 8] a friction lever 110 having an engagement portion and capable of rotating together with the spindle 12 as the spindle 12 rotates; The switch lever 70 further includes an engaged portion that engages with the engaging portion, When the seat belt is wound up, the friction lever 110 rotates in a first rotation direction in accordance with the winding rotation of the spindle 12, thereby rotating the switch lever 70 in a second rotation direction via engagement between an engaging portion of the friction lever 110 and an engaged portion of the switch lever 70, and moving the switch lever 70 in a direction from the non-lock canceling position toward the lock canceling position, When the seat belt is withdrawn, the friction lever 110 rotates in a second rotation direction in accordance with the rotation of the spindle 12, thereby rotating the switch lever 70 in a first rotation direction via engagement between an engaging portion of the friction lever 110 and an engaged portion of the switch lever 70, and moving the switch lever 70 in a direction from the lock canceling position toward the non-lock canceling position. A seat belt retractor 1 according to a first embodiment.

[0104] [Embodiment 9] The seat belt retractor 1 according to the first embodiment further includes a return spring 115 that biases the switch lever 70 in a direction from the lock canceling position toward the non-lock canceling position. [Explanation of symbols]

[0105] 1... seat belt retractor, 10... frame, 11... winding device, 12... spindle, 13, 14... left and right side plates, 13... left and right side plates, 13... side plate, 14... left and right side plates, 14... side plate, 15... shaft, 20... WS assembly, 21... steering disc, 22... webbing sensor lever (WS lever), 23... external teeth, 24... latch ring, 25... external teeth, 26... internal teeth, 27... latch ring engagement portion, 28... convex shaft, 29... shaft hole, 30... bearing plate, 31... peripheral wall portion, 32... AL R lever rotating shaft, 33...SW lever rotating shaft, 34...CS assembly fitting portion, 35...CS assembly, 36...housing, 37...car sensor lever (CS lever), 38...inertia body, 39...shaft hole, 40...ALR lever, 41...cylindrical portion, 42...ALR engagement claw portion, 43...ALR control cam, 48...ALR lever return spring, 48...return spring, 50...cam disc, 51...first operating region, 52...first non-operating region, 53...transition portion, 54...first contact portion, 55...groove portion , 56... second contact portion, 57... pressing portion, 58... pressing portion, 60... friction plate, 61... second operating region, 62... second non-operating region, 63, 65... pressed portion, 63... pressed portion, 64... switching cam, 65... pressed portion, 70... switch lever (SW lever), 71... cam disc engagement protrusion, 72... friction lever engagement protrusion, 73... cylindrical portion, 74... WS lock protrusion, 75... CS lock canceling protrusion, 76... return spring engagement protrusion, 80... wobble gear, 8 1...gear body, 82...hole portion, 83...cam disc engagement claw portion, 90...hub, 91...friction lever sliding groove portion, 92...eccentric portion, 93...rotating shaft, 95...engagement gear receiving portion, 100...clamping spring, 110...friction lever, 111...base portion, 112...SW lever engagement groove, 113...mounting portion, 114...sliding portion, 115...SW lever return spring, 115...return spring, 120...cover member, 124...engagement gear portion, 300...gear receiving portion, 301...shaft hole

Claims

1. a spindle that is rotatably supported by the frame and around which a seat belt is wound; A bearing plate fixed to the frame; a latch ring having inner and outer teeth formed on its inner and outer circumferential surfaces, respectively, and rotatably disposed on the bearing plate; a steering disk arranged coaxially with the latch ring, having external teeth formed on an outer circumferential surface thereof, and supported by the spindle so as to be integrally rotatable therewith; a webbing sensor lever that is pivotally supported on the steering disc at a position where it can be disengaged from the internal teeth of the latch ring and that displaces between a first operating position where the steering disc and the latch ring are rotated integrally by engaging with the internal teeth of the latch ring and a first non-operating position where the webbing sensor lever is not engaged with the internal teeth of the latch ring; a car sensor lever that is pivotally supported on a housing provided on the bearing plate at a position where it can be engaged with and disengaged from the external teeth of the steering disc, and that displaces between a second operating position where it engages with the external teeth of the steering disc and a second non-operating position where it does not engage with the external teeth of the steering disc in response to an applied acceleration, a switch lever rotatably supported on the bearing plate, the switch lever displacing between a lock canceling position where the switch lever does not engage with the external teeth of the latch ring and prevents the car sensor lever from displacing to the second operating position, and a non-lock canceling position where the switch lever engages with the external teeth of the latch ring and allows the car sensor lever to displace to the second operating position; a first disk that rotates at a speed slower than that of the spindle in response to rotation of the spindle, the first disk having a first contact portion on an outer periphery thereof that contacts the switch lever to displace the switch lever to the lock canceling position; Equipped with the first contact portion is displaced via the first disk by a rotation of the spindle in a first rotation direction corresponding to the winding of the seat belt and a rotation of the spindle in a second rotation direction opposite to the first rotation direction corresponding to the unwinding of the seat belt, and displaces the switch lever to the lock canceling position when the unwinding amount of the seat belt is maximum. Seat belt retractor.

2. The first disk is a first operating region for directing the switch lever to the lock canceling position; a first non-operating region on an outer periphery thereof that does not direct the switch lever to the lock canceling position, When the seat belt is withdrawn by a first amount, the seat belt rotates within the first operating range with respect to the switch lever. When the withdrawal amount of the seat belt exceeds a first withdrawal amount, the switch lever rotates within the range of the first non-operational region.

2. The seat belt retractor according to claim 1.

3. an ALR lever rotatably supported on the bearing plate, the ALR lever being displaceable between a third actuated position at which rotation of the steering disc in the seat belt withdrawing direction is prevented and a third inactuated position at which rotation of the steering disc in the seat belt withdrawing direction is not prevented; a second disk arranged coaxially with the first disk and rotating in response to the rotation of the first disk, the second disk having, on its outer periphery, a second operating region that prevents the ALR lever from being displaced to the third operating position by contacting the ALR lever, and a second non-operating region that allows the ALR lever to be displaced to the third operating position even when the second disk comes into contact with the ALR lever; Further equipped with The second disk is When the seat belt is withdrawn from a stationary state, the seat belt contacts the ALR lever in the second operation range until the seat belt withdrawn amount reaches a second withdrawn amount that is greater than the first withdrawn amount, When the seat belt is withdrawn by a larger amount than the second amount, the seat belt does not contact the ALR lever in the second operating range. When the seat belt is retracted from a state in which the seat belt is retracted by more than the second retracted amount, The seat belt does not contact the ALR lever in the second operation range until the seat belt withdrawal amount returns to the first withdrawal amount, When the seat belt is withdrawn by an amount equal to or less than the first amount, the seat belt comes into contact with the ALR lever in the second operation region.

3. The seat belt retractor according to claim 2.

4. the first disk further has a second contact portion that comes into contact with the ALR lever when the seat belt withdrawal amount is greater than the second withdrawal amount, the second contact portion prevents the ALR lever from being displaced to the third operating position by coming into contact with the ALR lever.

4. The seat belt retractor according to claim 3.

5. the second disk is provided between the bearing plate and the first disk, has a transition portion between the second non-operating region and the second operating region, and rotates by the second contact portion of the first disk pressing against the transition portion; 5. A seat belt retractor according to claim 4.

6. a return spring configured to bias the ALR lever in a direction from the third inoperative position toward the third operative position, 4. The seat belt retractor according to claim 3.

7. The bearing plate further includes a peripheral wall portion having a gear receiving portion provided on an inner peripheral surface thereof, a wobble gear including a gear body that is disposed on an inner peripheral surface side of the peripheral wall portion and is engageable with the gear receiving portion, a hole portion provided at the center of the gear body, and a claw portion that extends from the gear body and engages with a groove portion provided on an upper surface or a lower surface of the first disk; a hub having an eccentric portion that rotates while sliding on the inner periphery side of the hole portion of the gear body around an eccentric rotation axis as the spindle rotates, When the spindle rotates in the first rotational direction, As the eccentric portion of the hub rotates in the first rotational direction around the eccentric rotation axis, an outer peripheral surface of the eccentric portion of the hub presses an inner peripheral surface of the hole of the gear body, whereby the gear body engages with the gear receiving portion of the bearing plate, the wobble gear rotates in the second rotational direction, and the claw portion rotates the first disk in the second rotational direction.

2. The seat belt retractor according to claim 1.

8. a friction lever having an engagement portion and capable of rotating together with the spindle as the spindle rotates; The switch lever further includes an engaged portion that engages with the engaging portion, When the seat belt is wound up, the friction lever rotates in the first rotation direction in accordance with the winding rotation of the spindle, thereby rotating the switch lever in the second rotation direction via engagement between the engaging portion of the friction lever and the engaged portion of the switch lever, and moving the switch lever in a direction from the non-lock canceling position toward the lock canceling position. When the seat belt is withdrawn, the friction lever rotates in the second rotation direction in accordance with the rotation of the spindle for withdrawing the seat belt, thereby rotating the switch lever in the first rotation direction through engagement between the engaging portion of the friction lever and the engaged portion of the switch lever, and moving the switch lever in a direction from the lock canceling position toward the non-lock canceling position.

2. The seat belt retractor according to claim 1.

9. 2. The seat belt retractor according to claim 1, further comprising a return spring that biases the switch lever in a direction from the lock canceling position toward the non-lock canceling position.

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