PUNISHING, FORCE-LIMITING SEAT BELT DEVICE

Abstract

Seat belt assembly (20) comprising the following: a tightener (40); a rope (50) connected to the tensioner (40); and a torsion bar (60) with several teeth (70), wherein the rope (50) has slots (52) which interlock with the teeth (70).

Description

BACKGROUND

[0001] The invention relates to a seat belt assembly. In particular, a webbing strap of the seat belt assembly can act to tighten the webbing and limit the force on the webbing. Specifically, the seat belt assembly can tighten the webbing by pulling it towards the occupant upon detection of an impact. This tightening can help prevent "submarining," i.e., when the occupant slides forward under the webbing. The seat belt assembly can limit the force applied to the occupant's chest by slightly loosening the webbing if the force on the chest exceeds a threshold force.

[0002] Seat belt arrangements are already known from DE 102 59 635 A1 and DE 195 46 280 A1.

[0003] The object of the present invention is to provide a structurally advantageous seat belt arrangement and seat arrangement.

[0004] To solve this problem, a seat belt arrangement according to claim 1 and a seat arrangement according to claim 9 are proposed according to the invention. Advantageous embodiments of the invention are specified in the dependent claims and the following description. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view of a seat comprising a seat belt arrangement in a vehicle. Fig. Figure 2 is a perspective view of a section of the seat belt assembly attached to a section of a seat frame. Fig. Figure 3 is a side view of the seat belt arrangement. Fig. Figure 4 is a perspective view of the seatbelt arrangement. Fig. Figure 5 is a perspective view of another embodiment of the seat belt arrangement. Fig. Figure 6 is a side view of one end of a torsion bar. Fig. Figure 7 is a cross-sectional view of the torsion bar and a cable. DETAILED DESCRIPTION

[0005] With reference to the figures, in which matching reference numerals across the different views indicate matching parts, a seat belt assembly 20 comprises a tensioner 40, a rope 50 connected to the tensioner 40, and a torsion bar 60 having several teeth 70. The rope 50 has slots 52 that interlock with the teeth 70.

[0006] The seat belt assembly 20 provides both tensioning and force limitation in a single compact unit. Furthermore, the seat belt assembly 20 distributes the force limitation provided by the torsion bar 60 across both a pelvic ligament 32 and a shoulder ligament 34, instead of concentrating the effects of the force limitation in the shoulder ligament 34. The seat belt assembly 20 reduces complexity by having fewer parts.

[0007] With reference to Fig. 1 and Fig. 2 comprises a seating arrangement 10 in a vehicle 90, comprising a seat 12 which has a seat frame 14 and the seat belt arrangement 20. The seat 12 supports an occupant 99 in a seated position and may include cushions 16, 18. The seat 12 may include a seat base 13 and a seat back 15. The seat frame 14 may extend over the seat base 13 and the seat back 15.

[0008] Seat 12 can be a front or rear seat and can be in a transverse position. The one in Fig. The seat 12 shown is a bucket seat; however, seat 12 can alternatively be a bench seat or another type of seat. The seat frame 14 is a rigid structure that supports the seat cushions 16, 18, and the seat frame 14 can be tilted based on input from the occupant 99.

[0009] The seat belt assembly 20, when fastened, restrains the occupant 99 in seat 12, for example, during sudden deceleration of the vehicle 90. The seat belt assembly 20 may comprise a webbing 22, a retractor 24, a lap belt attachment 26, and a tongue 28 that engages with a buckle 30. The retractor 24 may be attached to a body part (without reference numeral) of the vehicle, for example, a B-pillar (without reference numeral) if seat 12 is a front seat, a C-pillar (without reference numeral) if seat 12 is a rear seat, etc. Alternatively, the retractor 24 may be attached to the seat frame 14.

[0010] The lap belt attachment 26 secures one end of the webbing 22 to the seat frame 14. The other end of the webbing 22 leads into the retractor 24, which may include a spool (without reference numeral) that unwinds and rewinds the webbing 22. The tongue 28 slides freely along the webbing 22 and, in engagement with the buckle 30, divides the webbing 22 into a lap belt 32 and a shoulder belt 34.

[0011] The seat belt arrangement 20 of Fig. 1 is a three-point belt, which means that when fitted, the webbing 22 is attached at three points around the occupant 99: the lap belt attachment 26, the retractor 24, and the buckle 30. The seat belt arrangement 20 may alternatively include a different arrangement of attachment points.

[0012] With reference to Fig. 3 and Fig. The seat belt assembly 20 comprises a bracket 42 that is attached to the seat frame 14, i.e., to the seat base 13. Alternatively, the bracket 42 can be integral with the seat frame 14, i.e., formed together as a single, continuous unit. The bracket 42 can support the tensioner 40 and / or the torsion bar 60. The bracket 42 can be made of any suitable material, e.g., metal or plastic. The bracket 42 can comprise a first plate 84, a second plate 86, and cross members 88 that fix the first plate 84 to the second plate 86. Either the first plate 84 or the second plate 86 can, for example, be directly connected to the seat frame 14.

[0013] The seatbelt assembly 20 includes a ratchet mechanism 78 to allow the rope 50 to slide freely in a first direction D1 and to be blocked in a second direction D2, which is opposite to the first direction D1, when no minimum tensile force is applied to the rope 50. As an example, this mechanism 78 can be the torsion bar 60 with the multiple teeth 70 and the rope 50 with slots 52 interlocking with the teeth 70, as shown in the illustration in Fig. 2-5 and as described in more detail below, and structural equivalents thereof.

[0014] With reference to Fig. 4. The torsion bar 60 can be attached to the bracket 42. In particular, the torsion bar 60 has a first end 64 that is fixed to the bracket 42, e.g., to the second plate 86 of the bracket 42, and a second end 66 that is spaced apart from the first end 64. The adjectives “first” and “second” are used throughout this document as designations and are not intended to indicate any rank or order. The first end 64 can be directly connected to the bracket 42, as shown in Fig. The first end 64 of the torsion bar 60 can alternatively be connected directly to the seat frame 14 or indirectly to one or more intermediate components (not shown) instead of the bracket 42.

[0015] The second end 66 can rotate freely relative to the support 42. For example, the second end 66 may not be attached to the support 42; e.g., the torsion bar 60 may project from the first end 64, as shown in Fig. 4 is shown. Alternatively, the second end 66 can be rotatably attached to the bracket 42, e.g. with a bolt, a pin, etc., to allow a rotational movement of the second end 66 relative to the bracket 42.

[0016] The torsion bar 60 can be designed to yield rotatably while being rotated by the cable 50, e.g., to deform plastically, as described in more detail below. In particular, the torsion bar 60 can be designed with a shape, dimensions, and material suitable for yielding when subjected to a threshold torsion force.

[0017] As an example, the torsion bar 60 can be used with reference to Fig. 4. The system comprises a shaft 94 at a first end 64 and a cylinder 96 at the second end 66. The cylinder 96 can have a larger diameter than the shaft 94. This larger diameter generates a moment applied by the rope 50 to the torsion bar 60 and promotes deflection of the shaft 94. The shaft 94 exhibits known elasticity such that, when the torsion bar 60 is subjected to a given torque about the second end 66, the second end 66 deflects rotatably to a predictable extent. The shaft 94 and the cylinder 96 can be integrally formed together, e.g., simultaneously as a single, continuous unit. Alternatively, the shaft 94 and the cylinder 96 can be formed separately and subsequently joined to one another.

[0018] As another example, shaft 94 and cylinder 96 can be used with reference to Fig. 5 be provided with splined teeth. In particular, the splined cylinder 96 can slidably receive the splined shaft 94, and the cylinder 96 and the shaft 94 are rotatably fixed to one another, i.e., they rotate together as a unit.

[0019] As explained in more detail below, the rotatable flexion of the torsion bar 60 can reduce the forces exerted by the seat belt 22 on the occupant's chest. In other words, upon impact of the vehicle 90, the retractor 24 blocks the seat belt 22 to prevent it from unwinding from the retractor 24. As the occupant moves forward, for example during a frontal collision, the occupant is pressed against the seat belt 22, and the seat belt 22 can exert forces on the occupant's chest. The torsion bar 60 is designed to flex when subjected to a threshold force resulting from the occupant being pressed against the seat belt 22.

[0020] The torsion bar 60 has several teeth 70 that are aligned circumferentially around the second end 66, e.g., on the cylinder 94. With reference to Fig. The multiple teeth 70 extend radially from the cylinder 94. The torsion bar 60 can encompass a base 72 between the teeth 70. Each of the teeth 70 has a gripping side 74 and a release side 76, each extending from the base 72.

[0021] The capturing faces 74 each have an interior angle θ to the base 72, i.e., the angle on the inside of the tooth between the capturing face 74 and the tangent to the base 72 where the capturing face 74 meets the base 72. Likewise, the release faces 76 each have an interior angle φ to the base 72, i.e., the angle on the inside of the tooth between the release face 76 and the tangent to the base 72 where the release face 76 meets the base 72. The interior angle θ of each capturing face 74 is larger than the interior angle φ of each release face 76.

[0022] With reference to Fig. 3, Fig. 4 and Fig. The rope 50 is connected to the tensioner 40. The rope 50 is also connected to the seatbelt buckle 30. The rope 50 has slots 52 that interlock with the teeth 70 of the torsion bar 60. The slots are spaced apart along an axis 54 of the rope 50. The rope 50 extends from the tensioner 40 around the torsion bar 60 to the buckle 30.

[0023] The rope 50 can comprise a sleeve 58 and a cord 56 extending coaxially through the sleeve 58. The cord 56 can be made of any suitable material, for example, metal. The cord 56 can be flexible with respect to the sleeve 58 and can axially reinforce the sleeve 58 when the rope 50 is under tension.

[0024] The sleeve 58 can define the slots 52. The sleeve 58 can be flexible with respect to the torsion bar 60 in such a way as to turn around the torsion bar 60, as shown in Fig. 3, Fig. 4 and Fig.Figure 7 shows that, for example, the sleeve 58 can be a sheath surrounding the cord 56 and can be made of a suitable material and thickness such that the sleeve 58 is flexible with respect to the torsion bar 60. As another example, the sleeve 58 can be a braid surrounding the cord 56 and defining the slots 52. In other words, the teeth 70 of the torsion bar 60 can engage the slots 52 defined by the braid. As yet another example, the sleeve 58 can comprise a series of interlocking sheaths that are, for example, hinged to one another. The sleeve 58 can be made of any suitable material, for example, metal.

[0025] The tensioner 40 can be connected directly or indirectly to the bracket 42 and / or the seat frame 14. The tensioner 40 can be of any suitable type, such as a ball-in-tube tensioner, in which an explosive charge drives a ball or balls via a gear connected to the cable 50; a piston tensioner, in which an explosive charge drives a piston attached to the cable 50; a mechanical tensioner, in which a tensioned spring attached to the cable 50 is released; or any other suitable type. The tensioner 40 is activated by a processing device 80, which is connected to an impact sensor 82 that may be positioned in a front bumper (without reference numeral) of the vehicle 90. As described in more detail below, the tensioner 40 winds up the cable 50.

[0026] In the event that the vehicle 90 is involved in an impact, the impact sensor 82 detects the impact event and sends a message to the processing device 80, which activates the tensioner 40. The tensioner 40 winds up the rope 50, and the slots 52 of the rope 50 slide over the release sides 76 of the teeth 70. This winding tensions the pelvic strap 32 and the shoulder strap 34 against the occupant 99, thus preventing "submarining," in which the occupant 99 would slide forward under the pelvic strap 32. As the occupant 99 is propelled forward by the momentum, the occupant 99 pulls on the pelvic strap 32 and the shoulder strap 34, both of which, via the tongue 28 engaged with the lock 30, tighten the rope 50. The slots 52 of the rope 50 engage with the gripping sides 74 of the teeth 70 and pull on them, thereby applying a torque to the torsion bar 60.The torsion bar 60 is rotatable, allowing the rope 50 to be extended and limiting the force exerted on the occupant 99 by the webbing 22. Thus, the torsion bar 60 provides a ratchet mechanism 62 to allow the rope 50 to slide freely in a first direction and to be blocked in a second direction, opposite to the first, unless a minimum tensile force is applied to the rope 50. The momentum of the occupant 99 can be further restrained at this point by an airbag (without reference numeral). The force limitation provided by the torsion bar 60 can reduce the forces exerted on the occupant 99's chest by the webbing 22.

Claims

[1] Seat belt assembly (20) comprising the following: a tightener (40); a rope (50) connected to the tensioner (40); and a torsion bar (60) with several teeth (70), wherein the rope (50) has slots (52) which interlock with the teeth (70). [2] Seat belt assembly (20) according to claim 1, further comprising a seat belt buckle (30) connected to the rope (50). [3] Seat belt arrangement (20) according to claim 1, wherein the torsion bar (60) comprises a base (72); Each of the teeth (70) has a capture side (74) and a release side (76), each extending from the base (72); wherein the capture side (74) and the release side (76) each have an interior angle (θ, φ) to the base (72); and the interior angle (θ) of each detection side (74) is greater than the interior angle (φ) of each release side (76). [4] Seat belt assembly (20) according to claim 1, further comprising a support (42) that supports the tensioner (40) and the torsion bar (60). [5] Seat belt arrangement (20) according to claim 4, wherein the torsion bar (60) has a first end (64) which is fixed to the support (42) and a second end (66) which is spaced apart from the first end (64), wherein the multiple teeth (70) are arranged circumferentially around the second end (66). [6] Seat belt arrangement (20) according to claim 1, wherein the rope (50) comprises a sleeve (58) and a cord (56) extending through the sleeve (58) coaxially to the sleeve (58), wherein the sleeve (58) defines the slots (52). [7] Seat belt arrangement (20) according to claim 1, wherein the slots (52) are spaced apart from each other along an axis (54) of the rope (50). [8] Seat belt arrangement (20) according to claim 1, wherein the rope (50) is made of metal. [9] Seating arrangement (10) comprising the following: a seat frame (14); a torsion bar (60) supported by the seat frame (14), which has several teeth (70), a tensioner (40) which is supported by the seat frame (14); a rope (50) which is connected to the tensioner (40) and has slots (52) which interlock with the teeth (70). [10] Seating arrangement (10) according to claim 9, further comprising a seat belt buckle (30) connected to the rope (50). [11] Seating arrangement (10) according to claim 9, wherein the torsion bar (60) comprises a base (72); Each of the teeth (70) has a capture side (74) and a release side (76), each extending from the base (72); wherein the capture sides (74) and the release side (76) each have an interior angle (θ, φ) to the base (72); and the interior angle (θ) of each detection side (74) is greater than the interior angle (θ) of each release side (76). [12] Seat arrangement (10) according to claim 9, wherein the torsion bar (60) has a first end (64) which is fixed to the seat frame (14) and a second end (66) which is spaced apart from the first end (64), wherein the multiple teeth (70) are arranged circumferentially around the second end (66). [13] Seating arrangement (10) according to claim 9, wherein the rope (50) comprises a sleeve (58) and a cord (56) extending through the sleeve (58) coaxially to the sleeve (58), wherein the sleeve (58) defines the slots (52). [14] Seating arrangement (10) according to claim 9, wherein the slots (52) are spaced apart from each other along an axis (54) of the rope (50). [15] Seating arrangement (10) according to claim 9, wherein the rope (50) is made of metal.

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