Seat-belt strap
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- AUTOLIV DEV AB
- Filing Date
- 2024-06-03
- Publication Date
- 2026-05-06
AI Technical Summary
Seat belt straps experience wear and tear during operation, leading to reduced tensile strength, and require a balance between maintaining strength and flexibility for comfortable wearing.
A seat belt strap with a 3/3 twill weave fabric, featuring an offset of two warp threads with each weft thread, providing high flexibility and maintaining tensile strength through a reduced number of binding points across the width while maintaining the same number of binding points in the warp direction, resulting in a 2-1-2-1 or 1-2-1-2 pattern along individual warp threads.
The seat belt webbing retains approximately 90% of its original breaking load after years of use, offering balanced twill weave with visible warp and weft threads on both sides, and allows for complex edge finishes and catch and fastening threads.
Smart Images
Figure EP2024065150_02012025_PF_FP_ABST
Abstract
Description
[0001] seat belt webbing
[0002] The present invention relates to a seat belt webbing for a seat belt system of a motor vehicle with a fabric made of warp threads and weft threads.
[0003] Seat belt webbing for motor vehicles typically features a twill weave. The twill weave is often a 2 / 2 twill weave, which is designed with an offset of two warp threads every other weft thread. This creates a kind of checkerboard pattern, with one thread alternating above and below two crossing threads in both the warp and weft directions.
[0004] Due to their restraining function for the occupant, seat belt webbings are subject to high tensile strength requirements. A problem with seat belts is the wear and tear that occurs during operation, which can reduce their tensile strength when worn. This wear can be caused, for example, by the seat belt webbing unwinding and running in over the belt retractor or the belt tongue.
[0005] From EP 2 659 039 B1 a safety belt with improved wear resistance is known which has a 2 / 1 / 1 / 2 twill weave having an offset of two warp threads with each weft thread.
[0006] Furthermore, the seat belt webbing is in indirect contact with the body and skin of an occupant, sometimes even in direct contact with the body and skin, particularly in the lap belt section on the abdomen of an occupant.
[0007] The object of the present invention is to provide an alternative weave for a seat belt webbing that provides sufficient strength in a used condition while simultaneously maintaining high flexibility for comfortable wearing of the seat belt. The invention achieves this object with the features of the independent claims.
[0008] A seat belt webbing for a seat belt system of a motor vehicle is proposed, comprising a fabric made of warp threads and weft threads, wherein the seat belt webbing has, at least in sections, a 3 / 3 twill weave having an offset of two warp threads with each weft thread.
[0009] The proposed seat belt webbing exhibits very high flexibility thanks to the 3 / 3 twill weave across the width of the seat belt webbing, as there are fewer bonding points across the width of the webbing compared to the prior art. Bonding points are the points in the fabric where a thread alternates between the top and bottom of the fabric. The number of bonding points is reduced, for example, compared to a fabric with a 2 / 2 or 2 / 1 twill weave or a wear-resistant fabric from the prior art. At the same time, however, the number of bonding points in the warp direction is maintained. In the warp direction, the proposed offset results in a 2-1-2-1 pattern, so that the number of bonding points in the warp direction of the fabric remains high, thus maintaining the high tensile strength of the seat belt webbing even after heavy use.The pattern along individual warp threads of the proposed seat belt webbing is therefore a 2-1-2-1 pattern or a 1-2-1-2 pattern. For example, 90% of the seat belt webbing's original breaking load can be retained after years of wear.
[0010] Overall, the proposed seat belt webbing has a balanced twill weave, with the warp threads visible on the surface in equal proportions as the weft threads on both sides of the fabric.
[0011] Preferably, the seat belt webbing has a 3 / 3 twill weave, which features an offset of two warp threads with each weft thread. This allows the advantageous properties to be utilized across the entire seat belt webbing. According to an advantageous further development, the seat belt webbing is finished at the edges with an edge yarn. With the proposed weave, the seat belt webbing can easily be provided with complex edge finishes.
[0012] In an advantageous embodiment, the seat belt webbing has catch and closure threads on the edges.
[0013] According to a further development, it is proposed that the seat belt webbing comprise multiple stripes aligned along the warp thread direction, with two warp threads in the stripes being offset to the left or to the right, and with adjacent stripes having a differently oriented offset. Preferably, the seat belt webbing comprises five stripes.
[0014] The invention will be explained below using preferred embodiments with reference to the attached figures.
[0015] Fig. 1 Illustration of a fabric sample of the seat belt webbing.
[0016] Figure 1 shows a section of the fabric 11 of the proposed seat belt webbing 10. This section of the fabric 11 of the seat belt webbing 10 can also be referred to as a repeat. The fabric 11 has warp threads 12, which run vertically in Figure 1 and are shown in white, and weft threads 13, which run horizontally in Figure 1 and are shown in dark. The weft threads 13 run in the 3 / 3 twill weave such that the weft thread 13 is alternately guided over and under three warp threads 12. The next weft thread 12 is guided with an offset of two warp threads 12, so that a characteristic twill line is formed. In the embodiment of Figure 1, the twill line runs to the top right, with the angle to the warp threads 13 being less than 45°.As can be seen in the repeat of Figure 1, a 2-1-2-1 pattern is created along the vertically running warp threads 12, which alternates with a 1-2-1-2 pattern with the next warp thread 12.
Claims
Claims:
1. Safety belt webbing (10) for a safety belt system of a motor vehicle with a fabric (11) made of warp threads (12) and weft threads (13), characterized in that the safety belt webbing (10) has at least in sections a 3 / 3 twill weave which has an offset of two warp threads (12) with each weft thread (13).
2. Safety belt webbing (10) according to claim 1, characterized in that the safety belt webbing (10) has a completely 3 / 3 twill weave which has an offset of two warp threads (12) with each weft thread (13).
3. Safety belt webbing (10) according to claim 1 or 2, characterized in that the safety belt webbing (10) is finished at the edges with an edge yarn.
4. Safety belt webbing (10) according to one of the preceding claims, characterized in that the safety belt webbing (10) has catch and closure threads on the edges.
5. Safety belt webbing (10) according to one of the preceding claims, characterized in that the safety belt webbing (10) has a plurality of strips in the direction of the warp threads (12), wherein the offset of two warp threads (12) in the strips is to the left or to the right, and wherein adjacent strips have a differently directed offset.