seat belt retractor

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, emergency locking retractors have been used as seat belt retractors for safely holding vehicle occupants in their seats. These retractors are equipped with an emergency locking mechanism that physically locks the withdrawal of the seat belt (webbing) using vehicle body acceleration sensing means that reacts to sudden acceleration, collision, or deceleration, thereby effectively and safely restraining the occupant.

[0003] For example, emergency locking mechanisms include the following: One detects a sudden withdrawal of the seat belt and prevents the spindle from rotating in the seat belt withdrawal direction (webbing acceleration sensing means: WS (Webbing Sensor)), and the other detects a sudden deceleration of the vehicle and prevents the spindle from rotating in the seat belt withdrawal direction (car body acceleration sensing means: CS (Car Sensor)). In either case, the spindle is locked by the swing of a locking member that rotates integrally with the spindle, causing the claw 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-retracting 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 use 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 out and engage with the internal teeth of the frame. However, if the webbing becomes taut after being rapidly wound up, the momentum causes the mass to move 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 acceleration sensing means due to vibration of the retractor caused by rapid winding of the webbing, the ball, which is an inertial member, moves, causing the lever to swing and engage with the latch member, 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 retractor (ALR) that prevents the seat belt from rotating in the retracting direction once it has been 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 a seat belt is fully withdrawn forcefully, the belt winding shaft may overrun, causing teeth to skip, resulting in loss of synchronization and lockup.The present disclosure aims 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 on 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 peripheral surfaces, respectively, and rotatably disposed on the bearing plate, a steering disc arranged coaxially with the latch ring, having external teeth formed on its outer peripheral surface, and supported on the spindle so as to be rotatable integrally with the latch ring, a webbing sensor lever pivotally supported on the steering disc at a position where it can engage with and disengage from the internal teeth of the latch ring, and displaceable between a first operating position where it engages with the internal teeth of the latch ring and a first inoperative position where it does not engage with the internal teeth of the latch ring, and a car sensor lever pivotally supported on a housing provided on the bearing plate at a position where it can engage with and disengage from the external teeth of the steering disc, and displaceable between a second operating position where it engages with the external teeth of the steering disc and a second inoperative position where it does not engage with the external teeth of the steering disc in response to acceleration acting thereon. The tractor comprises a switch lever rotatably supported on a bearing plate, the switch lever displacing 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 displaces via the first disk due to 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 aspect, when the seat belt is withdrawn to its maximum extent, the first contact portion of the first disc 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 accidental lockup from occurring when the seat belt is withdrawn to its maximum extent. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an exploded three-dimensional view of a seat belt retractor 1. FIG. [Figure 2] 1 is a diagram showing the configuration of a WS assembly 20. FIG. [Figure 3] 3A and 3B are diagrams showing the configuration of a latch ring 24. FIG. [Figure 4] 10A and 10B are diagrams illustrating the operation of the WS lever 22. [Figure 5] 3A and 3B are diagrams showing the configuration of a bearing plate 30. FIG. [Figure 6] 3A and 3B are diagrams showing the configuration of a cam disc 50. FIG. [Figure 7] 10 is a diagram for explaining in detail the second contact portion 56 of the cam disc 50. FIG. [Figure 8] 3A and 3B are diagrams showing the configuration of a friction plate 60. FIG. [Figure 9] 3A and 3B are diagrams showing the configuration of a wobble gear 80. FIG. [Figure 10] 10 is a diagram showing the configuration of the front side of the hub 90. FIG. [Figure 11] FIG. 2 is a diagram showing the configuration of the back side of the hub 90. [Figure 12] 10 is a diagram showing the configuration of a CS assembly 35. FIG. [Figure 13] 10 is a diagram showing the configuration of the front side of the SW lever 70. FIG. [Figure 14] 10 is a diagram showing the configuration of the back side of the SW lever 70. FIG. [Figure 15] 2A and 2B are diagrams showing the configuration of a friction lever 110. FIG. [Figure 16]3A and 3B are diagrams showing the configuration of an ALR lever 40. [Figure 17] 10A and 10B are diagrams for explaining the operations of the hub 90, the wobble gear, and the cam disc 50 due to the retraction and withdrawal of the seat belt. [Figure 18] FIG. 10 is a diagram showing the positional relationship of each member when WS / CS / ALR lock canceling is not activated. [Figure 19] FIG. 10 is a diagram showing the positional relationship of each member when WS / CS / ALR lock canceling is activated. [Figure 20] 10 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] 10 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. [Figure 23] FIG. 4 is a diagram showing the amount of seat belt withdrawal at each point in time. [Figure 24] 10 is a diagram illustrating that WS / CS / ALR lock canceling is activated when the seat belt withdrawal amount is equal to or greater than the second withdrawal amount. FIG. [Figure 25] FIG. 10 is a diagram illustrating that the WS / CS / ALR lock becomes operable when the seat belt is retracted so that the withdrawal amount of the seat belt is equal to or less than the second withdrawal amount and equal to or greater than the first withdrawal amount. [Figure 26] FIG. 10 is a diagram illustrating that the WS / CS / ALR lock becomes operable when the seat belt is retracted so that the withdrawal amount of the seat belt is equal to or less than the second withdrawal amount and equal to or greater than the first withdrawal amount. [Figure 27]10 is a diagram illustrating that WS / CS / ALR lock canceling is activated when the seat belt is retracted so that the seat belt withdrawal amount is equal to or less than a first withdrawal amount. FIG. [Figure 28] FIG. 10 is a diagram explaining that when the seat belt is pulled out 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, the WS / CS lock becomes operable and the ALR lock canceling is activated. [Figure 29] FIG. 10 is a diagram explaining that when the seat belt is pulled out 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, the WS / CS lock becomes operable and the ALR lock canceling is activated. [Figure 30] 10 is a diagram illustrating that WS / CS / ALR lock canceling is activated when the seat belt is pulled out to a second pulled-out amount or more. FIG. [Figure 31] 1 is a view 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 is seated in a vehicle seat in a normal posture, the direction in which the occupant faces forward is referred to as the forward direction, and the opposite direction is referred to as the rearward direction. Similarly, left / right and up / down are based on the case in which the occupant is seated in a vehicle seat in a normal posture. Clockwise and counterclockwise directions 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 pulled out 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 restrict 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 seatbelt retractor 1 will be described with reference to FIG.

[0017] The seat belt retractor 1 comprises a metal spindle 12 on 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 be rotatable integrally with it, 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 accordance with the rotation of the spindle 12, a friction plate 60 that rotates in accordance with 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, latch ring 24, WS assembly 20, cam disc 50, friction plate 60, wobble gear 80, and 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 that face each other across the axial center of the spindle 12, and 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 is disposed on the outside of one of the side plates 14, and the retractor 11 is disposed on the outside of the other side plate 13. A shaft 15 on one end 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 has a hub 90 fixed to its tip so as to rotate integrally with it.

[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 and internal teeth 26 on its inner circumferential surface.

[0022] The steering disc 21 has a shaft hole 29, external teeth 23 formed on its outer peripheral surface, and a convex shaft 28 that fits into the shaft hole of the WS lever 22 and supports the WS lever 22 so as to be able to swing freely. The shaft hole 29 is penetrated by the shaft 15 of the spindle 12. This allows the steering disc 21 to be supported on the spindle 12 so as to be rotatable integrally with it. That is, when the spindle 12 rotates, the steering disc 21 rotates at the same rotational 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. Under normal conditions, as shown in Figure 4(A), the WS lever 22 is in the 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 an angular acceleration equal to or greater than a predetermined value is applied to the WS assembly 20 (for example, when the spindle 12 rotates at high speed due to the seat belt being withdrawn 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 Figure 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 rotatable independently of each other. That is, even when 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 peripheral surface of the peripheral wall portion 31.

[0027] The ALR lever rotation shaft 32 is inserted into the cylindrical portion 41 of the ALR lever 40. The SW lever rotation 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 the cam disc engaging claw portion 83 of the wobble gear 80.

[0030] The first operation region 51 is a region used for WS / CS lock canceling, and the first non-operation region 52 is a region used to prevent WS / CS lock canceling. The transition region 53 is a switching cam that smoothly transitions between the first operation region 51 and the first non-operation region 52. Therefore, for example, a portion of the transition region 53 close to the first operation region 51 is in a state where WS / CS lock canceling is operable. In other words, at least a large portion of the transition region 53 can be said to be included in the first non-operation region 52. The first contact region 54 is located on the outer periphery of the cam disc 50, between the first operation region 51 and the first non-operation region 52. The transition region 53 has a slope-like shape that rises gently from the first non-operation region 52 toward the first operation region 51. On the other hand, the first contact region 54 has a mountain-like shape that rises steeply from the first non-operation region 52 toward the first operation 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 thereof near the transition portion 53 in the circumferential direction, and a pressing portion 58 formed on the other side thereof near 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 so 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 operation region 61 is a region where ALR lock canceling is activated by contact with the ALR lever 40 (described later), and the second non-operation region 62 is a region where ALR lock canceling is not activated. The switching cam 64 is a switching cam for smoothly transitioning between the second operation region 61 and the second non-operation region 62. Therefore, if the ALR lever 40 contacts the friction plate 60 at a portion of the switching cam 64 that is close to the second non-operation region 62, for example, the operation of the ALR lock canceling is limited. In other words, at least a portion of the switching cam 64 is included in the second non-operation region 62. The pressed portions 63 and 65 are provided between the second operation region 61 and the second non-operation 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 a wobble gear 80. The wobble gear 80 has a gear body 81, a hole 82 formed in the center of the gear body 81, and a cam disc engagement claw 83. The gear body 81 is disposed on the inner circumferential surface of the peripheral wall 31 of the bearing plate 30. As a result, the gear body 81 engages with a gear receiver 300 on the inner wall surface of the peripheral wall 31. The number of teeth of the gear body 81 is fewer than the number of teeth of the gear receiver 300. For example, in FIG. 9, the gear body 81 has 19 teeth, while in FIG. 5, the gear receiver 300 has 20 teeth. 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 55 of the cam disc 50.

[0036] (Hub 90) 10 and 11 are diagrams showing an example of the configuration of a hub 90. Specifically, FIG. 10 is a three-dimensional view of the hub 90 viewed from the front side (i.e., the positive direction of the z-axis), and FIG. 11 is a plan view of the hub 90 viewed from the back side (i.e., the negative direction of the z-axis). The hub 90 has a friction lever slide groove 91, an eccentric portion 92, and a rotation shaft 93. The friction lever slide groove 91 is formed on a substantially cylindrical peripheral surface 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 82 of the wobble gear 80. This allows the outer peripheral surface of the eccentric portion 92 to slide against the inner peripheral surface of the hole 82. The rotation shaft 93 is disposed centrally with respect to the hub 90. On the other hand, the rotation shaft 93 is disposed eccentrically with respect to the eccentric portion 92. The shaft 15 of the spindle 12 is fixed to the rotation shaft 93, and the rotation 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 rotation shaft 93, while the eccentric portion 92 rotates eccentrically in response to the rotation of the rotation shaft 93. A base 111 of a friction lever 110 is fitted into the friction lever sliding groove 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 a shaft that fits into a shaft hole 39 of the housing 36. This allows the CS lever 37 to be pivotally supported on the housing 36 so that it can swing freely. The inertial body 38 is capable of swinging 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 under normal conditions, the inertial mass 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 inoperative position.

[0040] On the other hand, for example, when a large acceleration acts on a 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. In other words, 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 positive direction of the z-axis), and Fig. 14 is a three-dimensional view of the SW lever 70 seen from the back side (i.e., the negative direction of the z-axis). The SW lever 70 has a cylindrical portion 73, a friction lever engaging protrusion 72, a cam disc engaging protrusion 71, a CS lock canceling protrusion 75, and a WS lock protrusion 74.

[0042] The SW lever rotation shaft 33 of the bearing plate 30 is inserted into the cylindrical portion 73. As a result, the SW lever 70 is rotatably supported on the bearing plate 30. The friction lever engagement protrusion 72 engages with the SW lever engagement groove 112 of the friction lever 110. The cam disc engagement protrusion 71 contacts the outer peripheral 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 engagement protrusion 71 is a cam follower guided by the outer peripheral surface of the cam disc 50, and functions as a part to which power for swinging the SW lever 70 is input. The CS lock canceling protrusion 75 is configured to be able to come into contact with and separate from the CS lever 37. The WS lock protrusion 74 is configured to be able to engage and disengage with the external teeth 25 of the latch ring 24.

[0043] (Friction Lever 110) 15 is a diagram showing an example of the configuration of a 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 to 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 engaging groove 112 formed to protrude radially outward from the outer periphery of the base 111 and to engage with the friction lever engaging protrusion 72 of the SW lever 70.

[0044] The base 111 has a notched groove extending in the radial direction on the opposite side of the notch in the approximate C-shape. This allows the base 111 to elastically deform (contract in diameter) in the radial direction. The base 111 contracts in diameter due to the elastic force of the clamping spring 100 attached to the attachment portion 113, thereby connecting the sliding portion 114 and the friction lever sliding groove portion 91 of the hub 90 by friction force. The magnitude of this friction force is approximately proportional to the elastic force of the clamping spring 100. In other words, since the friction lever 110 rotates due to the friction force between it and the hub 90, if a rotational torque exceeding this friction force acts on the friction lever 110 (for example, if the hub 90 attempts to rotate while 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 in 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 rotation 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 rotatably supported by the ALR lever rotation shaft 32 of the bearing plate 30.

[0046] <2. Operation of seat belt retractor 1> (Rotation of cam disc 50 due to seat belt retraction / retraction) In the seatbelt retractor 1, the spindle 12 and the cam disc 50 rotate in opposite directions. The sequence of their operations will be described with reference to Figures 17(A)-(C). In the following description, directions in an xy plane with the rotation axis 93 as the origin will be explained using an analog clock as an analog clock. Specifically, the positive and negative directions of the x-axis correspond to the "3 o'clock direction" and the "9 o'clock direction," respectively. Furthermore, 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 rotary shaft 93 and 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 withdrawal amount is at its maximum. In this state, the eccentric portion 92 is eccentric in the 3 o'clock direction when viewed from the rotary shaft 93. Also, the cam disc engaging claw portion 83 of the wobble gear 80 is engaged 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 component when the seatbelt is retracted, based on the situation in FIG. 17(A). When the seatbelt is retracted, the spindle 12 rotates clockwise, causing the eccentric portion 92 to rotate clockwise around the eccentric rotation axis 93. At this time, the outer peripheral surface of the eccentric portion 92 presses the gear body 81 from the inner peripheral surface of the hole 82 in the 6 o'clock to 7 o'clock direction (FIG. 17(B)(1)). As a result, the gear body 81 and the gear receiving portion 300 of the peripheral wall portion 31 engage in the 3 o'clock to 4 o'clock direction (FIG. 17(B)(2)). As the outer peripheral surface of the eccentric portion 92 slides against the inner peripheral surface of the hole 82, the gear body 81 rotates counterclockwise (FIG. 17(B)(3)). As a result, the cam disc engaging claws 83 of the wobble gear 80 engaged with the grooves 55 rotate the cam disc 50 counterclockwise.

[0049] FIG. 17(C) shows the positional relationship of each component when the seat belt is further retracted from the state shown in FIG. 17(B). As the seat belt is retracted, the eccentric portion 92 rotates clockwise around the eccentric rotation shaft 93. At this time, the outer peripheral surface of the eccentric portion 92 presses against the inner peripheral surface of the hole 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 in the 5 o'clock to 6 o'clock direction (FIG. 17(C)(2)), and the gear body 81 rotates counterclockwise (FIG. 17(C)(3)). As a result, the cam disc engaging claw 83 engaged with the groove 55 further rotates the cam disc 50 counterclockwise.

[0050] To summarize the above, when the spindle 12 rotates clockwise due to the seat belt being retracted, the cam disc 50 rotates counterclockwise. On the other hand, when the seat belt is unretracted, 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 WS / CS / ALR lock canceling will be described with reference to FIGS. 18 and 19.

[0052] Figure 18 is a diagram showing the positional relationship of each component when WS / CS / ALR lock canceling is not activated (i.e., when all of the WS lock, CS lock, and ALR lock are operable). In Figure 18, the SW lever 70 is displaced to a non-lock canceling position where the WS / CS lock canceling is not activated (i.e., the WS / CS lock is activated) by the action of the friction lever 110 (described below). Also in Figure 18, the ALR lever 40 is displaced to an ALR activated position where the ALR is activated by the action of the ALR lever return spring 48 (described below).

[0053] FIG. 19 is a diagram showing the positional relationship of each component when 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 engaging protrusion 71 of the SW lever 70 in the 6 o'clock direction. As a result, the SW lever 70 is urged counterclockwise around the cylindrical portion 73 and displaced to the lock canceling position where the WS / CS lock canceling is activated. Note that while 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 can also be displaced to the lock canceling position by the first contact portion 54 of the cam disc 50 pressing the cam disc engaging protrusion 71 of the SW lever 70 (see FIG. 24 described below).

[0054] 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 counterclockwise around the cylindrical portion 41 and displaced to the ALR inoperative position, where operation of the ALR lock is restricted. Note that while FIG. 19 shows a situation 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 can also be 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 below).

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

[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 explained with reference to Figures 20(A) and 20(B). Figures 20(A) and 20(B) are diagrams focusing on area AR1 in Figures 18 and 19, respectively.

[0057] Figure 20(A) shows a situation in which the SW lever 70 is in the non-lock canceling position and the CS lock is activated. In Figure 20(A), the inertial mass 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, counterclockwise rotation of the steering disc 21 (i.e., rotation when withdrawing the seat belt) is prevented.

[0058] On the other hand, Figure 20(B) shows a situation in which the SW lever 70 is in the lock canceling position, limiting the operation of the WS / CS lock. As shown in Figure 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 pressure on the CS lever 37 prevents the inertial body 38 from coming out of the recess on the back side of the CS lever 37. In other words, the CS lock canceling protrusion 75 prevents the CS lever 37 from moving 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 do not engage with each other. This limits the operation of the CS lock.

[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 Figure 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 Figure 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.

[0061] 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. If the WS lever 22 is displaced from the WS non-engagement position to the WS engagement position at this time (i.e., if the steering disc 21 and the latch ring 24 rotate together), counterclockwise rotation of the steering disc 21 is prevented by the latch ring 24, which is engaged with the SW lever 70.

[0062] On the other hand, according to Figure 20(B), when the SW lever 70 is in the lock canceling position, the WS locking 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 engaging position (see Figure 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, allowing the WS lock to operate (see FIG. 21). On the other hand, when the SW lever 70 is in the lock canceling position, rotation of the latch ring 24 is not prevented even if the WS lever 22 is displaced to the WS engaging position, limiting operation of the WS lock (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 22(B). Figures 22(A) and 22(B) are diagrams focusing on the area AR2 in Figures 18 and 19, respectively.

[0065] 22(A) shows a state in which the ALR lever 40 is in the ALR operating position and the ALR lock is operable. The ALR engagement claw 42 of the ALR lever 40 is wound around the cylindrical portion 41 and is biased clockwise 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 42 to a position where it can engage with the external teeth 23 of the steering disc 21. As a result, counterclockwise rotation of the steering disc 21 (i.e., 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) shows a situation in which the ALR lever 40 is in the ALR inoperative position and 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 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, counterclockwise rotation of the steering disc 21 (i.e., rotation when withdrawing the seat belt) is not prevented, and 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 engagement between the ALR engaging claw 42 and the external teeth 23 of the steering disc 21 is not prevented, and therefore the ALR lock can be activated (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 engaging claw 42 and the external teeth 23 of the steering disc 21 is prevented, and therefore activation of the ALR lock is limited (see FIG. 22(B)).

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

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

[0071] [Time A] Figure 24 is a diagram showing the state of the seat belt retractor 1 at time point A (the time point when the withdrawal amount of the seat belt is equal to or greater than the second withdrawal amount). As shown in Figure 24, at time point A, the first contact portion 54 of the cam disc 50 is in contact with the cam disc engaging 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 Figures 20 and 21, when the SW lever 70 is in the lock canceling position, operation of the WS / CS lock is restricted.

[0072] Also, 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 seatbelt retractor 1 activates the WS / CS / ALR lock canceling at time A when the seatbelt is pulled out to approximately its maximum extent. That is, at time A, the activation of all of the WS / CS / ALR locks is restricted.

[0074] [Time B and Time C] Figure 25 is a diagram showing the state of the seatbelt retractor 1 at time B (the time when the withdrawal amount of the seatbelt is equal to or less than the second withdrawal amount and equal to or greater than the first withdrawal amount). As the seatbelt is retracted, the hub 90 rotates clockwise (Figure 25(1)). In contrast, as described with reference to Figure 17, the cam disc 50 rotates counterclockwise (Figure 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, and 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 (Figure 25(3)).

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

[0076] 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, clockwise rotation of the friction lever 110 is prevented by engagement with the friction lever engaging projection 72 of the switch lever 70. 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 the hub 90 independently of the friction lever 110, while keeping the switch lever 70 displaced 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 retracted from time B. Further retraction of the seat belt causes the hub 90 to rotate clockwise (FIG. 26(1)). In response, the cam disc 50 rotates counterclockwise (FIG. 26(2)). This causes the pressing portion 57 provided on one side of the second contact portion 56 of the cam disc 50 to press the pressed portion 63 of the friction plate 60. As a result, the friction plate 60 rotates counterclockwise together with the cam disc 50, and the switching cam 64 of the friction plate 60 begins to press the ALR control cam 43 of the ALR lever 40. This causes the ALR lever 40 to rotate counterclockwise around the cylindrical portion 41. At time C, the ALR lever 40 has begun to move toward the ALR inoperative region, but is still in the ALR operating position.

[0078] Furthermore, the clockwise rotation of the hub 90 ((1) in FIG. 26) biases the friction lever 110 clockwise ((4) in FIG. 26). This biases the SW lever 70 counterclockwise (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 does not actually activate the WS / CS lock canceling.

[0079] As described above, the seatbelt retractor 1 does not activate the WS / CS / ALR lock canceling at time B and time C when the seatbelt is wound up so that the 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 B and time 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 withdrawal amount of the seat belt is equal to or less than the first withdrawal amount). Further retraction 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. This causes the first operating area 51 of the cam disc 50 to come into contact with the cam disc engaging protrusion 71 of the SW lever 70, and the SW lever 70 is oriented 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 oriented to the ALR inoperative position.

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

[0082] [Time points E and F] FIG. 28 is a diagram showing the state of the seat belt retractor 1 at time point E (the time point when the withdrawal amount of the seat belt is equal to or greater than the first withdrawal amount and equal to or less than the second withdrawal amount). Withdrawal of the seat belt causes the hub 90 to rotate counterclockwise (FIG. 28(1)). This causes the cam disc 50 to rotate clockwise (FIG. 28(2)). Meanwhile, the rotation of the hub 90 urges the friction lever 110 counterclockwise (FIG. 28(3)). As a result, the friction lever 110 urges the SW lever 70 to rotate clockwise around the cylindrical portion 73 via the engagement between the SW lever engaging groove 112 and the friction lever engaging protrusion 72 (FIG. 28(4)). When the cam disc 50 rotates within the first non-operating 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, and therefore the ALR lever continues to be maintained in 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 engaging projection 71 of the switch lever 70 is in contact with the cam disc 50, the switch lever 70 does not rotate further in the clockwise direction. Therefore, counterclockwise rotation of the friction lever 110 is prevented by engagement with the friction lever engaging projection 72 of the switch lever 70. 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. As a result, the seat belt retractor 1 allows the hub 90 to rotate independently of the friction lever 110, while the switch lever 70 is displaced 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. Further withdrawal of the seat belt causes the hub 90 to rotate counterclockwise (FIG. 29(1)), and the cam disc 50 to rotate clockwise (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 begins to press the pressed portion 65 of the friction plate 60. As a result, the friction plate 60 begins to rotate clockwise. That is, the ALR lever 40 begins to move relatively from the second operating region 61 of the friction plate 60 toward the second inoperating region 62. Note that 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, and therefore the ALR lever 40 continues to be maintained in the ALR inoperating 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 is withdrawn to a position equal to or greater than the first withdrawal amount and equal to or less than the second withdrawal 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, but the ALR lock is restricted from operation.

[0088] [Point G] Figure 30 is a diagram showing the state of the seat belt retractor 1 at time G (the time when the withdrawal amount of the seat belt reaches the second withdrawal amount). Withdrawal of the seat belt causes the hub 90 to rotate counterclockwise ((1) in Figure 30). As a result, the friction lever 110, which rotates together with the hub 90, biases the SW lever 70 clockwise 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 clockwise around the cylindrical portion 73.

[0089] On the other hand, the rotation of the hub 90 causes the cam disc 50 to rotate clockwise ((2) in FIG. 30), which causes the first contact portion 54 of the cam disc 50 to press the cam disc engaging projection 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 ((2) in Figure 30), 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 G when the seat belt is withdrawn and the withdrawal amount is equal to or greater than the second withdrawal amount, the WS / CS / ALR lock canceling of the seat belt retractor 1 is activated, i.e., the operation of the WS / CS / ALR locks is restricted.

[0092] In one embodiment, the first withdrawal amount can also be said to be the withdrawal amount at which the cam disc engaging protrusion 71 of the SW lever 70 contacts the boundary between the first operating region 51 and the first non-operating region 52 of the cam disc 50 when the SW lever 70 is urged clockwise around the cylindrical portion 73. In other words, when retracting the seat belt, the first withdrawal amount can also be said to be the withdrawal amount at which the cam disc engaging protrusion 71 of the SW lever 70 finishes climbing the "slope" of the transition portion 53 of the cam disc 50. Also, when withdrawing the seat belt, the first withdrawal amount can also be said to be the withdrawal amount at which the cam disc engaging protrusion 71 of the SW lever 70 starts to descend the "slope" of the transition portion 53 of the cam disc 50.

[0093] In one embodiment, the second withdrawal amount can also be said to be the amount of seat belt withdrawal 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 withdrawal amount can also be said to be the amount of seat belt withdrawal 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 withdrawn, when the withdrawal amount reaches the second withdrawal amount by retracting 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-described 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 has been described in which the friction lever 110 displaces the SW lever 70 to the non-lock canceling position. However, the seatbelt retractor 1 may also 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 seatbelt retractor 1 that includes a SW lever return spring 115 instead of the friction lever 110. The SW lever 70 of FIG. 31 further includes a return spring engaging protrusion 76. When the cam disc 50 rotates within 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 a clockwise moment about the cylindrical portion 73 generated 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 around 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 caused by 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 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 peripheral surfaces, respectively, and rotatably disposed on a bearing plate 30; a steering disc (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; 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 is displaceable between a first operating position (WS engaging position) where the lever engages with the internal teeth (26) of the latch ring (24) to rotate the steering disc (21) and the latch ring (24) together, and a first non-operating position (WS non-engaging position) where the 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 acting acceleration, a switch lever 70 pivotally supported on the bearing plate 30, the switch lever 70 displacing between a lock canceling position where it 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 it 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 that has a first contact portion 54 on its outer periphery that contacts the switch lever 70 to displace the switch lever 70 to a lock canceling position; Equipped with The first contact portion 54 is displaced via the first disc (cam disc 50) by the rotation of the spindle 12 in a first rotation direction corresponding to the retraction 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 withdrawal of the seat belt, and displaces the switch lever 70 to the lock canceling position when the withdrawal amount of the seat belt is maximum. Seat belt retractor 1.

[0097] [Embodiment 2] The first disc (cam disc 50) is a first actuation region 51 that directs the switch lever 70 to a lock canceling position; a first inoperative region 52 on the outer periphery that does not direct the switch lever 70 to the lock canceling position, When the withdrawal amount of the seat belt is equal to or less than the first withdrawal amount, the seat belt rotates within the range of the first operating region 51 relative to the switch lever 70, When the withdrawal amount of the seat belt exceeds the first withdrawal amount, the switch lever 70 rotates within the range of the first inoperative 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 displacing between a third operating position (ALR operating position) that prevents rotation of the steering disc 21 in the seat belt withdrawing direction and a third non-operating position (ALR non-operating position) that does not prevent rotation of the steering disc 21 in the seat belt withdrawing direction; 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; Furthermore, The second disc (friction plate 60) is When the seat belt is pulled out from a stationary 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 withdrawal amount of the seat belt is greater than the second withdrawal amount, the seat belt does not contact the ALR lever 40 in the second operation area 61, When retracting the seat belt from a state where it has been 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 withdrawal amount is equal to or less than the first withdrawal amount, the seat belt contacts the ALR lever 40 in the second operation area 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 withdrawal amount of the seat belt 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). A seat belt retractor 1 according to a 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 area 62 and the second operating area 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. A seat belt retractor 1 according to a 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). A seat belt retractor 1 according to a third embodiment.

[0102] [Embodiment 7] The bearing plate 30 further has a peripheral wall portion 31 having a gear receiving portion 300 provided on its inner peripheral surface, 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 the 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 rotation axis (93) as the spindle (12) rotates; When the spindle 12 rotates in the 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 against 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 (cam disc engaging claw portion 83) rotates the first disc (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 has an engaged portion that engages with the engaging portion, When the seat belt is retracted, the friction lever 110 rotates in a first rotation direction in accordance with the rotation of the spindle 12 for retraction, thereby rotating the switch lever 70 in a second rotation direction via engagement between the engaging portion of the friction lever 110 and the 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 the second rotation direction in accordance with the rotation of the spindle 12, thereby rotating the switch lever 70 in the first rotation direction via engagement between the engaging portion of the friction lever 110 and the 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 seatbelt retractor 1 according to the first embodiment further comprises 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...retractor, 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 engaging protrusion, 72...friction lever engaging protrusion, 73...cylindrical portion, 74...WS lock protrusion, 75...CS lock canceling protrusion, 76...return spring engaging protrusion, 80...wobble gear, 8 1...gear body, 82...hole portion, 83...cam disc engaging claw portion, 90...hub, 91...friction lever sliding groove portion, 92...eccentric portion, 93...rotating shaft, 95...engaging gear receiving portion, 100...clamping spring, 110...friction lever, 111...base portion, 112...SW lever engaging groove, 113...mounting portion, 114...sliding portion, 115...SW lever return spring, 115...return spring, 120...cover member, 124...engaging gear portion, 300...gear receiving portion, 301...shaft hole

Claims

1. a spindle 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 peripheral 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 integrally rotatable; a webbing sensor lever that is pivotally supported on the steering disc at a position where it can be engaged with and disengaged from the internal teeth of the latch ring, and that is displaceable 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 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 disc, and that displaces between a second operating position where it engages with the external teeth of the steering disc and a second inoperable 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 it 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 it 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 lower rotational speed than the spindle in response to rotation of the spindle, the first disk having a first contact portion on its outer periphery that comes into contact with 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 rotation of the spindle in a first rotation direction corresponding to retraction of the seat belt and rotation of the spindle in a second rotation direction opposite to the first rotation direction corresponding to withdrawal of the seat belt, and displaces the switch lever to the lock canceling position when the withdrawal amount of the seat belt is maximum. Seat belt retractor.

2. The first disk is a first operating region in which the switch lever is oriented toward the lock canceling position; a first non-operating region on an outer periphery that does not direct the switch lever to the lock canceling position, When the withdrawal amount of the seat belt is equal to or less than a first withdrawal amount, the seat belt rotates within the range of the first operation 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 inoperative region.

2. The seat belt retractor according to claim 1.

3. an ALR lever rotatably supported on the bearing plate, the ALR lever displacing between a third actuation position at which rotation of the steering disc in the seat belt withdrawing direction is prevented and a third inactuation 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 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; Furthermore, The second disk is When the seat belt is withdrawn from a stationary state, the seat belt contacts the ALR lever in the second operating range until the seat belt withdrawal amount reaches a second withdrawal amount that is greater than the first withdrawal amount; When the withdrawal amount of the seat belt is greater than the second withdrawal amount, the seat belt does not contact the ALR lever in the second operation range, When the seat belt is retracted from a state in which the seat belt is withdrawn by more than the second withdrawal amount, The seat belt does not contact the ALR lever in the second operation range until the withdrawal amount of the seat belt returns to the first withdrawal amount, When the withdrawal amount of the seat belt is equal to or less than the first withdrawal amount, the seat belt contacts the ALR lever in the second operation range.

3. The seat belt retractor according to claim 2.

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

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 when the second contact portion of the first disk presses against the transition portion; 5. The seat belt retractor according to claim 4.

6. a return spring that biases 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 has 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 the 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 the upper surface or the lower surface of the first disk; a hub having an eccentric portion that rotates while sliding on the inner circumferential 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 rotation direction, As the eccentric portion of the hub rotates in the first rotation direction around the eccentric rotation axis, the outer peripheral surface of the eccentric portion of the hub presses the 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 rotation direction, and the pawl portion rotates the first disk in the second rotation 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 has an engaged portion that engages with the engaging portion, When the seat belt is retracted, the friction lever rotates in the first rotation direction in accordance with the rotation of the spindle for retraction, 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 withdrawal, thereby rotating the switch lever in the first 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 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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