Seat belt retractor

Abstract

A seat belt retractor for a vehicle seat belt webbing includes a frame and a spool rotatably mounted to the frame. The spool is configured to wind a seat belt webbing thereon. The first belt and the second belt are symmetrically arranged in the reel around the axis of the reel. The first strap and the second strap are configured to plastically deform to at least partially absorb a load on the seat belt webbing.

Description

[0001] Related applications

[0002] This application claims priority to U.S. Patent Application Serial No. 18 / 495,813, filed October 27, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to a seat belt retractor for vehicle seat belt webbing. Background Technology

[0004] U.S. Patent No. 6,926,221 (“221 Patent”) discloses a known seatbelt retractor for vehicle seatbelt webbing. This seatbelt retractor includes a frame, a spool rotatably mounted on the frame, and first and second energy-absorbing spirals. The first energy-absorbing spiral includes three strips arranged symmetrically with respect to the axis of rotation of the spool. The second energy-absorbing spiral similarly includes three strips arranged symmetrically with respect to the axis of rotation of the spool. Unlike the first energy-absorbing spiral, the second energy-absorbing spiral can be selectively deactivated during use. Therefore, the two energy-absorbing spirals can be initially connected in parallel during a first phase to achieve a particularly high energy absorption load. After the first phase, the second energy-absorbing spiral can be deactivated via a pyrotechnic actuator to achieve a lower energy absorption load.

[0005] Therefore, the '221 patent seatbelt retractor requires pyrotechnics and numerous straps to achieve the desired load level. Consequently, the '221 patent seatbelt retractor is a relatively expensive and complex seatbelt retractor. Summary of the Invention

[0006] According to one aspect of the invention, alone or in combination with any other aspect, a seatbelt retractor for vehicle seatbelt webbing includes a frame and a spool rotatably mounted to the frame. The spool is configured to wind seatbelt webbing thereon. A first and a second webbing are symmetrically arranged in the spool about an axis of the spool. The first and second webbing are configured to plastically deform to at least partially absorb loads on the seatbelt webbing.

[0007] According to one aspect of the invention, alone or in combination with any other aspect, a seatbelt retractor for vehicle seatbelt webbing includes a locking disc rotatable relative to a frame. In an emergency situation with the vehicle, rotation of the locking disc relative to the frame is prevented. A torsion bar has a first end rotatably fixed to a reel and a second end rotatably fixed to the locking disc. Plastic deformation of the torsion bar allows the reel to rotate about an axis relative to the locking disc in an emergency situation. First end portions of a first strap and a second strap are connected to the locking disc. Second end portions of the first strap and the second strap are connected to the reel such that rotation of the reel relative to the locking disc plastically deforms the first strap and the second strap.

[0008] According to one aspect of the invention, alone or in combination with any other aspect, the seat belt retractor has a high energy absorption (“EA”) load level and a low EA load level. At the high energy absorption (“EA”) load level, the torsion bar, as well as the first and second belts, plastically deform to absorb energy from the seat belt webbing. At the low EA load level, the torsion bar alone plastically deforms to absorb energy from the seat belt webbing.

[0009] According to one aspect of the invention, alone or in combination with any other aspect, after the reel has rotated a predetermined amount relative to the locking disc, the second end portions of the first and second straps simultaneously disengage from the reel. This disengagement switches the seatbelt retractor from a high EA load level to a low EA load level without the use of pyrotechnics.

[0010] According to one aspect of the invention, alone or in combination with any other aspect, the seatbelt retractor has a first energy absorption state and a second energy absorption state, in the first energy absorption state, each strap of the seatbelt retractor is operatively connected to the spool such that rotation of the spool relative to the locking disc causes all straps to plastically deform, and in the second energy absorption state, each strap of the seatbelt retractor is operatively disconnected from the spool such that no strap plastically deforms when the spool rotates relative to the locking disc. Attached Figure Description

[0011] After reading the following description with reference to the accompanying drawings, those skilled in the art will understand the foregoing and other features and advantages of the present invention, wherein:

[0012] Figure 1 This is a perspective side view of a seatbelt retractor according to an exemplary embodiment of the present disclosure;

[0013] Figure 2 It is along Figure 1 A cross-sectional view taken from line 2-2;

[0014] Figure 3 yes Figure 1A rear exploded view of a portion of the seatbelt retractor;

[0015] Figure 4 yes Figure 3 The exploded view of the portion shown;

[0016] Figure 5 yes Figure 1 Rear view of part of the seat belt retractor;

[0017] Figure 6 yes Figure 1 A front cross-sectional view of a portion of the seatbelt retractor;

[0018] Figure 7 yes Figure 1 A perspective side view of a portion of the seatbelt retractor;

[0019] Figure 8 It is shown Figure 1 A graph showing the energy absorption load characteristics of the seat belt retractor;

[0020] Figure 9 yes Figure 1 A rear exploded view of an alternative configuration of part of the seat belt retractor;

[0021] Figure 10 yes Figure 9 A rear cross-sectional view of a portion of the seatbelt retractor; and

[0022] Figure 11 yes Figure 9 A front cross-sectional view of a portion of the seatbelt retractor. Detailed Implementation

[0023] Figures 1 to 6 The illustration shows an example seatbelt retractor 10 design according to the present disclosure. The seatbelt retractor 10 includes a reel 12 having a first cylindrical portion 14 and a second cylindrical portion 16 forming part of the first cylindrical portion. The second cylindrical portion 16 has an outer diameter and an inner diameter that are larger than the outer diameter and inner diameter of the first cylindrical portion 14.

[0024] The spool 12 is rotatably mounted to the frame 18 such that a length of seatbelt webbing (not shown for clarity) is wound onto and unwound from the spool (e.g., wound onto and unwound from the first cylindrical portion 14). More specifically, the spool 12 is rotatable in a webbing pull-out direction 20 and an opposite webbing take-up direction 22. A spring 24 acts on the spool 12 to bias the spool in the webbing take-up direction 22.

[0025] Torsion bar 26 extends axially through the interior of spool 12. A first end 28 of torsion bar 26 is rotatably secured to spool 12 (e.g., via spline-in-grove engagement of one or more splines) such that the first end rotates with the spool (i.e., does not rotate relative to the spool). A second end 30 of torsion bar 26 is rotatably secured to locking disc 32 such that the second end rotates with the locking disc. For example, the second end 30 of torsion bar 26 may be rotatably secured to locking disc 32 via spline 34, which is received on or in a groove 36 adjacent to the inner periphery 37 of the locking disc.

[0026] The locking disc 32 is only part of the locking mechanism 38, which is configured to prevent rotational movement of the reel 12 relative to the frame 18 in the webbing pull-out direction 20 under certain conditions. The locking mechanism 38 also includes a pawl 40, one end of which is pivotally mounted to the locking disc 32. The other end of the pawl 40 includes a plurality of teeth 42. With the aid of conventional locking mechanisms (such as those shown and described in U.S. Patent No. 10,315,617 to Franz et al. (“617 Patent”, the subject of which is incorporated herein by reference in its entirety), the pawl 40 can be released from its idle position (in... Figure 2 (As shown in the diagram) it pivots to engage with tooth 44, which is formed around an opening 46 in a supplementary portion 48 of frame 18. After the pawl tooth 42 engages the frame tooth 44 (e.g., immediately or almost immediately thereafter), rotational movement of the locking disc 32 relative to frame 18 in the webbing pull-out direction 20 is prevented. Furthermore, rotation of the second end 30 of the torsion bar in the webbing pull-out direction 20 is also prevented due to the mutual engagement between the groove 36 in the locking disc 32 and the spline 34 on the torsion bar 26. When the torsion bar 26 is prevented from rotating in the webbing pull-out direction, the spool 12, which is rotatably fixed to the first end 28 of the torsion bar 26, is at least partially restricted from rotation in the webbing pull-out direction 20. The torsion bar 26 thus operatively connects the spool 12 to the locking mechanism 38.

[0027] The turbine wheel 50 of the pretensioner 52 is rotatably fixed to the locking disc 32, such that the turbine wheel and the locking disc rotate together with each other. As shown, the turbine wheel 50 is formed separately from the locking disc 32 and is subsequently attached to the outer periphery 54 of the locking disc in a rotatably fixed manner. Alternatively, the turbine wheel 50 and the locking disc 32 may have a one-piece construction for rotatably fixing each other. Although not shown in detail, the pretensioner 52 includes a tube 56 housing a gas generator and one or more features that rotate the turbine wheel 50 in the webbing take-up direction 22 in response to actuation of the gas generator. An example of such a pretensioner is shown and described in patent '617. The rotation of the turbine wheel 50 is transmitted to the reel 12 via the locking disc 32 and the torsion bar 26, thereby rotating the reel in the webbing take-up direction 22 to wind the seat belt webbing onto the reel. The winding rotation of the spool 12 effectively reduces or eliminates slack in the seat belt webbing wound on the spool, and also pulls the seat belt webbing tightly and firmly against the vehicle occupants (not shown).

[0028] The fixing disc 58 is also rotatably fixed to the locking disc 32, such that the fixing disc and the locking disc rotate together. As shown, the fixing disc 58 is formed separately from the locking disc 32 and is subsequently attached to the outer periphery 54 of the locking disc in a rotatable manner. Alternatively, the fixing disc 58 and the locking disc 32 can have a one-piece construction for rotatable fixation to each other. The fixing disc 58 is a one-piece construction having a hub 60 and an annular flange 62 extending radially from the hub, the fixing disc being connected to the locking disc 32 via the hub 60. At least a portion of the hub 60 extends into the second cylindrical portion 16, while the flange 62 remains outside the second cylindrical portion.

[0029] The axial surface 64 of the flange 62 on the spool side is adjacent to and / or abuts against the outer axial surface 66 of the second cylindrical portion 16. This specific positioning helps to hold the insert 68, as well as the first strap 70 and the second strap 72, within the second cylindrical portion 16 during use. It should be noted that any contact between the axial surface 64 of the flange 62 and the outer axial surface 66 does not (or does not significantly) restrict the rotation of the spool 12, the rotation of the retaining disc 58, or any relative rotation between the spool and the retaining disc.

[0030] The insert 68 is substantially annular in shape and has a first axial surface 74 that is adjacent to and / or contacts the inner axial surface 76 of the second cylindrical portion 16. Furthermore, the outer periphery 78 of the insert 68 is adjacent to and / or contacts the inner periphery 80 of the second cylindrical portion 16, which extends axially between the outer axial surface 66 and the inner axial surface 76. The insert 68 can be rotatably secured to the spool 12 such that the insert and the spool rotate together with each other. For example, the insert 68 may include a radially extending protrusion 82 that is received in a recess 84 of the inner periphery 80 of the second cylindrical portion 16.

[0031] The second axial surface 86 of the insert 68 is adjacent to and / or abuts against the axial surface 64 of the flange 62, such that a cavity 88 is defined between the insert and the retaining disk 58. More specifically, the cavity 88 is annular and is defined by the inner axial surface 90 of the insert 68, the axial surface 64 of the flange 62, the outer periphery 92 of the hub 60, and the inner periphery 94 of the insert. It should be noted that any contact between the axial surface 64 of the flange 62 and the second axial surface 86 of the insert 68 does not (or does not significantly) restrict the rotation of the reel 12, the rotation of the retaining disk 58, or any relative rotation between the reel and the retaining disk. Furthermore, the flange 62 may be configured such that the flange is at least partially located in the second cylindrical portion 16. In such a configuration, the flange 62 may be radially adjacent to and / or radially abut against the inner periphery 80 of the second cylindrical portion 16.

[0032] At least a portion of the first strap 70 and the second strap 72 extends substantially circumferentially within the cavity 88. The first strap 70 has a first end portion 96 (i.e., the end closest to the axis 98, on which the spool 12 and the locking disc 32 are coaxially arranged), which is secured to the hub 60 in the second cylindrical portion 16. Specifically, the first end portion 96 includes a first end face 100 that circumferentially abuts (i.e., directly contacts) a complementary inner shoulder 102 of the hub 60. The inner shoulder 102 is formed by a radial descent on the inner periphery 104 of the hub 60. The first end portion 96 extends from the inner shoulder 102 through a substantially radially extending slot 106 in the hub 60 toward the outer periphery 92 of the hub. The first end portion 96 and the slot 106 can be configured such that a press fit and / or friction engagement is formed between the first end portion and the slot. The press fit and / or friction engagement between the first end portion 96 and the slot 106 rotatably secures the first end portion to the fixing plate 58, thereby securing it to the locking plate 32.

[0033] The middle portion 108 of the first tape 70 extends circumferentially around the outer periphery 92 of the hub 60 from the first end portion 96 in the tape pull-out direction 20 to form an inner section S1. Then, the middle portion 108 makes a U-turn to form a U-turn section S2 in the cavity 88. After making the U-turn, the middle portion 108 extends in the tape take-up direction 22 to form an outer section S3.

[0034] The second end portion 110 of the first band 70 (i.e., the end opposite to the first end portion 96 and furthest from the axis 98) extends from the intermediate portion 108. The second end portion 110 engages the inner periphery 94 of the insert 68. In particular, the second end portion 110 includes a second end face 112 that circumferentially abuts against a complementary inner shoulder 114 of the insert 68. The inner shoulder 114 is formed by a radial descent on the inner periphery 94 of the insert 68.

[0035] The second tape 72 is structurally identical (or at least substantially identical) to the first tape 70, and is therefore arranged in the take-up unit 10 in the same or similar manner as the first tape. Therefore, the above description of the first tape 70 applies to the second tape 72. However, the tapes 70 and 72 are arranged symmetrically with respect to the axis 98. In this way, a symmetrical load distribution is achieved, resulting in particularly low loads on the reel 12 via the fixing disc 58, the locking disc 32, and the torsion bar 26. Figures 5 to 6 As shown, the lengths of the straps 70 and 72 (measured from the first end face 100 to the second end face 112) are such that the straps overlap each other. This overlap does not inhibit the function of either strap 70 or 72.

[0036] like Figure 7 As shown, because the turbine impeller 50 and the fixed disc 58 are fixed to the locking disc 32, and the insert 58, together with the fixed disc, forms a cavity 88 for receiving the tapes 70, 72, these features can be pre-assembled as a single unit 116 before being connected to the rest of the corresponding retractor 10. More specifically, the locking disc 32, turbine impeller 50, fixed disc 58, insert 68, and the first tape 70 and the second tape 72 can appear or be packaged as a pre-assembled single unit 116. Then, during the assembly of the retractor 10, this single unit 116 can be selected and connected to the corresponding spool 12 and torsion bar 26.

[0037] In use, when the retractor 10 is installed in a vehicle (not shown), the occupant grasps the buckle tongue (not shown), which attaches to the seatbelt webbing. The seatbelt webbing winds onto the reel 12, and the buckle tongue and seatbelt webbing are pulled away from the retractor to wear the seatbelt by pulling the webbing across the occupant's body and engaging the buckle tongue with the buckle (not shown). As the seatbelt webbing is pulled away from the retractor 10, the webbing unwinds from the reel 12 and the reel rotates in the webbing withdrawal direction 20, overcoming the bias of the spring 24. Because the reel 12 is connected to the torsion bar 26, and the torsion bar is connected to the locking disc 32, the rotation of the reel affects the rotation of the locking disc in the webbing withdrawal direction 20.

[0038] After the occupant wears the seat belt, in the normal state of the vehicle, such as when the occupant adjusts his or her position in the vehicle seat (not shown), the resulting low-acceleration, low-speed pull-out and retracting motion of the seat belt webbing will produce a low-acceleration rotational motion of the spool 12 and a resulting combined rotational motion of the locking disc 32.

[0039] In an emergency situation involving the vehicle (e.g., during a high-speed collision), the pretensioner 52 and locking mechanism 38 can be actuated. The pretensioner 52 can be actuated in response to a vehicle sensor (not shown), such as an accelerometer mounted in the vehicle, detecting rapid deceleration of the vehicle indicating the occurrence of an emergency. The pretensioner 52 can alternatively or additionally be actuated in response to a vehicle sensor (not shown), such as a forward-looking radar unit or a forward-looking camera, detecting an anticipated and potentially unavoidable emergency. The pretensioner 52 can alternatively or additionally be actuated in response to a vehicle sensor (not shown) detecting movement of an occupant indicating the occurrence of an emergency; the vehicle sensor is such as a camera or capacitive sensor pointing towards or located near the occupant. Any desired system or mechanism can be used to determine whether and when the pretensioner 52 is actuated.

[0040] Actuation of the pretensioner 52 is initiated by actuation of the micro gas generator. Upon actuation, the micro gas generator produces or generates a gas that pushes one or more features against the turbine impeller 50, causing the turbine impeller to rotate in the webbing take-up direction 22. The rotation of the turbine impeller 50 is transmitted to the reel 12 via the locking disc 32 and the torsion bar 26, thus rotating the reel in the webbing take-up direction 22 to wind the seatbelt webbing onto the reel. This winding rotation of the reel 12 effectively reduces or eliminates slack in the seatbelt webbing wound on the reel and also tightly pulls the seatbelt webbing against the occupant.

[0041] However, in an emergency, the occupant can move against the seatbelt webbing that extends across the occupant's body. After the pretensioner 52 has been activated, this occupant movement will apply a load to the seatbelt webbing and force the reel 12 to accelerate in the webbing pull-out direction 20. The locking mechanism 38 can be configured such that under such reel acceleration, the pawl 40 pivots from its idle position to a position where the teeth 42 of the pawl engage the teeth 44 of the frame, preventing further rotation of the locking disc 32 and the second end 30 of the torsion bar 26 in the webbing pull-out direction 20. Thus, when the teeth 42 of the pawl engage the teeth 44 of the frame, the locking disc 32 is rotatably locked to the frame 18 (e.g., to the supplementary portion 48 of the frame) via the pawl 40.

[0042] However, due to the vehicle being in an emergency, the load in the seat belt webbing may be sufficient to cause the spool 12 to rotate in the webbing pull-out direction 20 via the rotation of the first end 28 of the torsion bar 26 relative to the second end 30, resulting in torsion and plastic deformation of the torsion bar. The plastic deformation of the torsion bar 26 absorbs at least a portion of the load in the seat belt webbing and / or at least a portion of the impact energy of the seat belt webbing on the moving occupant.

[0043] Through this relative motion, the straps 70, 72, positioned between the fixed disc 58 (which is in a rotationally locked state via its connection to the locking disc 32) and the reel 12 (which rotates relative to the fixed and locking discs via the plastic deformation of the torsion bar 26), undergo plastic deformation and wind around the outer periphery 92 of the hub 60 in the webbing pull-out direction 20. Specifically, the inner shoulder 114 of the insert 68 (which is rotatably fixed to the rotating reel 12) forces and / or pushes the second end faces 112 of the straps 70, 72 in the webbing pull-out direction 20, causing the straps to plastically deform and wind around the hub 60. Because the straps 70, 72 have the same or substantially similar structure and are arranged in the retractor 10 in the same or substantially similar manner, the straps deform together and simultaneously, although the retractor 10 can be configured such that one strap deforms before the other. This plastic deformation of the straps 70, 72 further absorbs the seatbelt webbing load and / or impact energy.

[0044] As the tapes 70 and 72 are wound around the outer periphery 92 of the hub 60, the length of their inner sections S1 increases, and their U-shaped bend sections S2 shift in the tape pull-out direction 20. This deformation also shortens the outer section S3. The winding of the tapes 70 and 72 and the alteration of sections S1, S2, and S3 continue in this manner until the second end 112 shifts to or beyond its corresponding U-shaped bend section S3. The second end 112 simultaneously reaches or at least partially moves through the U-shaped bend section S3, causing the tapes 70 and 72 to unwind at their U-shaped bend sections, thereby eliminating the U-shaped bend sections and the outer sections S2 and S3. As the tapes 70 and 72 unwind, the second end 112 detaches from the inner shoulder 114 and becomes a free end. Because the tapes 70 and 72 have the same or substantially similar structure and are arranged in the retractor 10 in the same or substantially similar manner, the tapes simultaneously disengage from the inner shoulder 114, although the retractor 10 can be configured such that one tape disengages before the other.

[0045] When the spool 12 rotates relative to the second end 30 of the torsion bar 26 in the webbing pull-out direction 20 and causes the torsion bar to twist, the plastic deformation of the torsion bar and the straps 70, 72 is used to absorb energy / seat belt webbing load. The total energy absorption (“EA”) load is the sum of the EA load when the torsion bar 26 twists and deforms and the EA load when the straps 70, 72 deform and wrap around the hub 60. Through the total EA load, the impact energy applied to the moving occupant via the seat belt webbing is absorbed and mitigated, and the load applied to the seat belt webbing is limited.

[0046] Figure 8 This is a graph showing the variation of the EA load generated via the torsion bar 26 and the belts 70, 72 when absorbing impact energy as described above. The horizontal axis shows the rotational stroke (angle) of the spool 12 relative to the locking disc 32 (and therefore also relative to the second end 30 of the torsion bar 26 and the fixing disc 58).

[0047] like Figure 8 As shown, when the rotational travel of the spool 12 relative to the locking disc 32 is zero, the EA load is zero. Then, when the aforementioned relative rotation begins and the travel begins to increase, the EA load, initially caused by the torsion / deformation of the torsion bar 26, increases proportionally. As the travel increases until a certain value ( Figure 8 At point A), in addition to the torsion of torsion bar 26, plastic deformation of belts 70 and 72 also begins. The total EA load is the EA load of torsion bar 26 (at... Figure 8 The image shows the TB) and the EA load of the tape (in Figure 8 The sum of EA loads (shown as BA) is used. As the stroke increases further, the sum of EA loads across the entire retractor 10 stops increasing at a fixed value ( ). Figure 8Point b in the diagram). Afterwards, despite the increase in stroke, the EA load remains at a fixed value ( Figure 8 (From point b to point c in the middle).

[0048] As the travel increases further and the second ends 112 of the belts 70 and 72 disengage from the inner shoulder 114, the EA load of the entire retractor 10 drops sharply. Figure 8 Points c to d in the diagram), because the EA load is no longer generated by the belt, but solely by the torsion bar 26 (TB). In other words, after the second ends 112 of the belts 70 and 72 simultaneously disengage from the inner shoulder 114, the belt no longer absorbs energy. After this disengagement, although the stroke increases (from... Figure 8 (To the right of point d in the middle), the EA load still maintains a decreasing value.

[0049] like Figure 8 As demonstrated by the change in EA load between midpoints c and d, the reel 10 switches directly from a high EA load to a low EA load without using non-mechanical features, such as, for example, pyrotechnics. Therefore, the change in EA load level is purely mechanical (i.e., independent of pyrotechnics) and occurs after the reel 12 has rotated to a certain and / or predetermined extent.

[0050] Furthermore, by including two symmetrically arranged tapes, the EA load is symmetrically distributed in the retractor 10. Having two tapes is also advantageous because the dual tapes 70, 72 can provide a greater EA load in a smaller axial package than a single tape can provide. Figure 8 The EA load and EA duration are also considered. In other words, in order for a single tape to provide the same EA load and EA duration as tapes 70 and 72, a single tape must typically have a much larger axial width than tapes 70 and 72.

[0051] The energy absorption characteristics of the retractor 10 can be adjusted and customized according to different vehicle structures and occupant geometries. For example, the EA load of the torsion bar 26 can be adjusted by changing the torsion bar material and / or the diameter and thickness of the torsion bar. The tape material and thickness can also be adjusted to achieve the desired tape EA load (BA). Furthermore, the lengths of the tapes 70 and 72 can be selected to achieve the desired tape EA load (BA) and EA duration (i.e., from...). Figure 8 The time or rotational distance taken to travel from point a to point c.

[0052] Figures 1 to 6 The retractor 10 is merely an example of a retractor designed in accordance with the teachings of this disclosure. Figures 9 to 11 It depicts another one. Figures 9 to 11 The retractor 10 is basically similar to Figures 1 to 6 The retractor 10, some differences are described below. Compared to... Figures 1 to 6 different, Figures 9 to 11 The hub 60 and flange 62 of the retaining disc 58 are separate from each other. This two-piece construction of the retaining disc 58 allows one of the hub 60 and flange 62 to be application-agnostic, while the other can be application-specific. The hub 58 includes two protrusions 118 that are received in corresponding recesses 120 in the flange 62 to rotatably secure the flange to the hub. The inner periphery 102 of the hub 60 also includes a recess 122 in which the spline 124 of the locking disc 32 is received to rotatably secure the hub to the locking disc.

[0053] Figures 9 to 11 The protrusion 118 of the hub 60 includes a substantially circumferentially extending recess 126 into which a first end portion 96 of the straps 70, 72 extends. The end wall of the recess 126 defines an inner shoulder 102, into which a first end face 100 of the straps 70, 72 abuts (i.e., directly contacts) the inner shoulder 102. The first end portion 96 extends from the inner shoulder 102 through the recess 126 toward the outer periphery 92 of the hub 60. The first end portion 96 and the recess 126 can be configured such that a press-fit and / or friction engagement is formed between the first end portion and the recess. The press-fit and / or friction engagement between the first end portion 96 and the recess 126 rotatably secures the first end portion to the hub 60, and thus to the locking disc 32.

[0054] and Figures 1 to 6 The retractor 10 is different. Figures 9 to 11 The retractor 10 does not include the insert 68. Therefore, the cavity 88 is defined between the reel 12 and the retaining disc 58. More specifically, the cavity 88 is annular and is defined by the inner axial surface 76 of the second cylindrical portion 16, the axial surface 64 of the flange 62, the outer periphery 92 of the hub 60, and the inner periphery 80 of the second cylindrical portion. Furthermore, although the flange 62 may be positioned adjacent to the outer axial surface 66 of the second cylindrical portion 16, at least a portion of the flange may be within the second cylindrical portion.

[0055] The inner periphery 80 of the second cylindrical portion 16 of the spool includes radially extending protrusions 128. These protrusions 128 circumferentially abut and force the second end faces 112 of the straps 70, 72 to rotate in the same manner as the inner shoulder 114 of the insert 68. By omitting the insert 68, Figures 9 to 11 The retractor 10 can reduce manufacturing time and material costs.

[0056] and Figures 1 to 6 The strips 70 and 72 are different. Figures 9 to 11 The strips 70 and 72 in the middle include selected lengths such that the strips do not overlap each other along their lengths.

[0057] Figures 9 to 11The retractor 10 also includes a bearing 130 located directly radially between the locking disc 32 and the spool 12. The bearing 130 helps the spool 12 rotate relative to the locking disc 32 and can absorb radial tolerances in the retractor 10.

[0058] although Figures 9 to 11 The retractor 10 is shown as being with Figures 1 to 6 The retractors 10 are separate, but any features discussed and / or described with respect to one of the retractors may be incorporated into the other if needed. For example, any of the retractors 10 may be configured to include or exclude the insert 68, the one-piece retaining disc 58, or the two-piece retaining disc 58. Figures 1 to 6 Hub configuration, Figures 9 to 11 Hub configuration, Figures 1 to 6 flange configuration, Figures 9 to 11 Flange configuration, bearing 130, etc.

[0059] The above description is an example of the present invention. Of course, for the purposes of describing the invention, it is impossible to describe every conceivable combination of components or methods; however, those skilled in the art will recognize that many further combinations and arrangements of the invention are possible. Therefore, the invention is intended to encompass all such changes, modifications, and variations falling within the spirit and scope of the appended claims.

Claims

1. A seat belt retractor for vehicle seat belt webbing, comprising: frame; A reel, rotatably mounted to the frame and the seat belt webbing wound around the reel; and A first strap and a second strap are symmetrically arranged in the spool about the axis of the spool, and the first strap and the second strap are configured to plastically deform to absorb at least part of the load on the seat belt webbing.

2. The seat belt retractor according to claim 1, further comprising: A locking disc, the locking disc being rotatable relative to the frame, the locking disc being prevented from rotating relative to the frame in an emergency situation of the vehicle, and the first end portions of the first strap and the second strap being connected to the locking disc; A torsion bar having a first end rotatably fixed to the spool and a second end rotatably fixed to the locking disc, the plastic deformation of the torsion bar allowing the spool to rotate about an axis relative to the locking disc in the emergency state, the second end portions of the first and second straps being connected to the spool such that rotation of the spool relative to the locking disc causes plastic deformation of the first and second straps.

3. The seat belt retractor according to claim 2, wherein, In the normal state of the vehicle, the rotation of the spool causes the rotation of the locking disc via the torsion bar.

4. The seat belt retractor according to claim 2, wherein, The seatbelt retractor has a high energy absorption (EA) load level and a low energy absorption load level. At the high energy absorption (EA) load level, the torsion bar, as well as the first and second straps, plastically deform to absorb energy from the seatbelt webbing. At the low energy absorption load level, the torsion bar alone plastically deforms to absorb energy from the seatbelt webbing.

5. The seat belt retractor according to claim 4, wherein, After the reel rotates a predetermined amount relative to the locking disc, the second end portions of the first strap and the second strap simultaneously disengage from the reel, such disengagement switching the seat belt retractor from the high energy absorption load level to the low energy absorption load level.

6. The seat belt retractor according to claim 4, wherein, The switching from the high EA load level to the low EA load level does not depend on the use of fireworks.

7. The seat belt retractor of claim 2, further comprising a retaining plate rotatably fixed to the locking plate and the first end portions of the first strap and the second strap, such that the first end portions of the first strap and the second strap are connected to the locking plate via the retaining plate.

8. The seat belt retractor according to claim 7, wherein, The fixing disc includes a hub and a flange extending radially from the hub, the first end portions of the first strip and the second strip are fixed to the hub, and rotation of the spool relative to the locking disc forces the first strip and the second strip to plastically deform and wind around the hub.

9. The seat belt retractor according to claim 8, wherein, The hub and flange are integrally formed into one piece, making the fixed plate a one-piece structure.

10. The seatbelt retractor according to claim 8, wherein, The hub and flange are separate from each other, making the retaining plate a two-piece construction, with the protrusion of the hub received in the recess of the flange to rotatably secure the flange to the hub.

11. The seat belt retractor according to claim 8, wherein, The first end portions of the first strap and the second strap each extend from the interior of the hub toward the outer periphery of the hub. Each of the first strap and the second strap includes an intermediate portion extending between the first end portion and the second end portion. Each intermediate portion has a first section extending circumferentially around the outer periphery of the hub from the corresponding first end portion, a U-shaped bend section extending from the first section, and a second section extending from the U-shaped bend section to the corresponding second end portion.

12. The seatbelt retractor of claim 7, further comprising an insert received in and rotatably fixed to the reel, the second end portions of the first strap and the second strap each abutting an inner shoulder of the insert, and rotation of the insert relative to the locking disc forcing the second end portions of the first strap and the second strap to rotate relative to the first end portions via the inner shoulder.

13. The seat belt retractor according to claim 12, wherein, The retaining disc includes a hub and a flange extending radially from the hub, the first end portions of the first strap and the second strap are secured to the hub, and cavities extending therein, at least partially, of the first strap and the second strap are defined between the hub, the flange, and the insert.

14. The seat belt retractor according to claim 13, wherein, At least a portion of the hub extends into the reel, such that the first end portions of the first strip and the second strip are connected to the hub in the reel, the flange being outside the reel and having an axial surface adjacent to and / or abutting against at least one of the outer axial surfaces of the insert and the reel.

15. The seatbelt retractor of claim 2, further comprising an insert received in and rotatably fixed to the reel, the second end portions of the first strap and the second strap each abutting an inner shoulder of the insert, and rotation of the insert relative to the locking disc forcing the second end portions of the first strap and the second strap to rotate relative to the first end portions via the inner shoulder.

16. The seat belt retractor according to claim 2, wherein, The inner periphery of the spool includes two radially extending protrusions, the second end portions of the first and second straps abutting the protrusions, and rotation of the spool relative to the locking disc forces the second end portions of the first and second straps to rotate relative to the first end portions via the protrusions.

17. The seatbelt retractor of claim 16, further comprising a retaining disc rotatably fixed to the locking disc and the first end portions of the first strap and the second strap, such that the first end portions of the first strap and the second strap are connected to the locking disc via the retaining disc, the retaining disc including a hub and a flange extending radially from the hub, the first end portions of the first strap and the second strap being fixed to the hub, and cavities extending therein from the first strap and the second strap being defined between the hub, the flange, and the reel.

18. The seat belt retractor of claim 2, further comprising a pretensioner having a turbine impeller rotatably fixed to the locking disc, wherein actuation of the pretensioner rotates the reel in the webbing winding direction via the turbine impeller, the locking disc, and the torsion bar.

19. The seat belt retractor according to claim 1, wherein, The seat belt retractor has a first energy absorption state and a second energy absorption state. In the first energy absorption state, each strap of the seat belt retractor is operatively connected to the spool, such that rotation of the spool relative to the locking disc causes all straps to plastically deform. In the second energy absorption state, each strap of the seat belt retractor is operatively disconnected from the spool, such that no strap plastically deforms when the spool rotates relative to the locking disc.

20. The seat belt retractor according to claim 1, wherein, The spool includes a first cylindrical portion and a second cylindrical portion, the seat belt webbing is wound on the first cylindrical portion, the second cylindrical portion has a larger diameter than the first cylindrical portion, and the first belt and the second belt are located in the second cylindrical portion.

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