Steering column arrangement

Abstract

A steering column assembly comprising a steering column cover having an inner cover section (4) and an outer cover section (6), wherein one end of the inner cover section (4) is positioned within one end of the outer cover section (6) so that the two cover sections (4, 6) can be telescopically adjusted to adjust the overall length of the cover, wherein the outer cover section (6) is provided with an elongated slot (14) extending axially along the outer cover section (6), and the inner cover section (4) is also provided with an elongated slot (16) extending axially along the inner cover section (4), wherein the two slots (14, 16) always at least partially overlap over the height adjustment range of the steering column assembly (2), and further comprising an end stop (18),which extends through the slot (14) in the outer trim section (6) and the slot (16) in the inner trim section (4), wherein the end stop (18) can move freely along both slots (14, 16) when the steering column assembly (2) is positioned between the position at maximum retracted height and the position at maximum extended height, and is arranged to abut one end (16a) of the inner slot (16) and one end (14a) of the outer slot (14) when the steering column assembly (2) reaches the position at extended height, and to abut the opposite ends (14b, 16b) of the two slots (14, 16) when the steering column assembly (2) reaches the position at retracted height, characterized in that the end stop (18) has a shaft (20) passing through the two slots (14, 16) and a Head (22) which prevents the end stop (18) from being pulled through the slots (14, 16),while allowing a sliding movement of the end stop (18).

Description

[0001] The present invention relates to a steering column arrangement having the features of the preamble of claim 1.

[0002] Such a steering column arrangement is known from US 2014 / 0 116 185 A1.

[0003] It is known to provide a steering column assembly comprising a steering column cover that surrounds and supports a steering shaft. The cover is attached to the vehicle body for secure positioning of the steering shaft, and the shaft, in turn, is supported by bearing assemblies within the cover so that it can rotate. One end of the shaft is attached to the vehicle's steering wheel, and the other is attached to the road wheels by a steering mechanism, such as a rack and pinion.

[0004] It is important to allow the steering column to collapse in the event of a crash in which the driver is thrown onto the steering wheel, as can happen if the driver is not wearing a seat belt. To enable controlled collapse, a two-piece fairing is typically provided, comprising an inner fairing section and an outer fairing section. One end of the inner fairing section is positioned within one end of the outer fairing section, allowing the two fairing sections to telescope together. The steering shaft must also be capable of collapsing, ideally also by being constructed from two parts that can telescopically move.

[0005] The provision of the two-piece cover can also allow the driver to adjust the overall length of the cover and thus the height of the steering column assembly. This allows the position of the steering wheel to be moved backward or forward in the vehicle to provide a comfortable position for drivers of different shapes and sizes. This requires that the two parts of the cover be connected by a releasable clamping arrangement.

[0006] To prevent damage to the telescopic fairing during adjustment, a stop is known to be provided fixed to the outer fairing section, which engages a slot in the inner section. As the inner section moves in and out of the outer section during adjustment, the stop moves along the slot in the inner fairing section and ultimately abuts one end of the slot to prevent further movement. The stop abuts one end of the slot to limit the extent of the height extension adjustment and the other end to limit the extent of the height retraction adjustment.

[0007] An object of the present invention is to provide a steering column assembly which improves some of the problems associated with steering column assemblies as described above, particularly when a large degree of height adjustment is desired from a steering column assembly having a short length in the fully retracted height position.

[0008] The object underlying the invention is achieved with a steering column arrangement having the features of claim 1.

[0009] The invention provides a steering column assembly comprising a steering column cover having an inner cover portion and an outer cover portion, wherein one end of the inner cover portion is positioned within one end of the outer cover portion so that the two cover portions can be telescopically adjusted to adjust the overall length of the cover, wherein the outer cover portion is provided with an elongated slot extending axially along the outer cover portion, and the inner cover portion is also provided with an elongated slot extending axially along the inner cover portion, wherein the two slots always at least partially overlap over the height adjustment range of the steering column assembly, and which further comprises an end stop,which extends through the slot in the outer trim section and the slot in the inner trim section, wherein the end stop can move freely along both slots when the steering column assembly is positioned between the maximum retracted height position and the maximum extended height position, and is arranged to abut one end of the inner slot and one end of the outer slot when the steering assembly reaches the extended height position, and to abut the opposite ends of the two slots when the steering assembly reaches the retracted height position.

[0010] The end stop establishes the retracted height position and the extended height position—defined as the longest and shortest lengths of the fairing. Because it can move along both slots, each slot can be shorter than would be the case if a single slot were provided and the end stop were fixed to one of the fairings. This allows the slots to be set back from the outer end of the respective fairing sections to an extent greater than would be possible for a single slot for a given panel overlap and adjustment range. By setting the slots back from the outer ends, the strength of the fairing sections at the outer ends is comparatively higher than would be possible if the slot stopped closer to the ends.

[0011] According to the invention, the end stop comprises a shaft passing through the two slots and a head that prevents the end stop from being pulled through the slots while allowing a sliding movement of the end stop.

[0012] To assist in axially guiding the end stop along the slots, the end stop may comprise an elongated bracket that fits into a pair of grooves extending along either side of the slot in the outer panel, with the bracket capable of sliding along the grooves during use. These grooves should extend beyond the ends of the slot.

[0013] The end stop can be positioned so that the head is positioned on the outside of the outer panel. The slots can be provided in the uppermost area of ​​the two panel sections so that the head sits over the slots and prevents the end stop from falling through the slots.

[0014] The end stop may be held in place by a cover member in the two slots. This may comprise a cover plate secured to the outer panel, for example, by one or more screws, bolts, rivets, or other fasteners.

[0015] The end stop stem can be fragile, so it will break when subjected to a high force applied from the ends of the slots in the event of a crash, allowing the fairing to collapse beyond its retracted height position. Because the two fairings are slightly offset, the compressive force applied to the stem creates a shear force that causes the stem to shear in a controlled manner.

[0016] The inner trim section may be positioned closer to the steering wheel than the outer trim section.

[0017] The outer fairing portion may be fixed to a clamping arrangement which, in use, is movable between a first position in which it clamps the outer fairing portion to the inner fairing portion to prevent height adjustment and a second position in which the outer fairing portion is released from the inner fairing portion to allow height adjustment.

[0018] The steering column arrangement can be adjustable in both tilt and height.

[0019] An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is an exploded perspective view of the trim sections and end stop and cover of an embodiment of a steering column assembly within the scope of the present invention; Fig. 2 is a cutaway side view of the steering column assembly in an intermediate position between the retracted height position and the extended height position; Fig. 3 a corresponding view, wherein the steering column assembly is in the position with the Fig. 2 height; and Fig. 4 a corresponding view, wherein the steering column assembly is in the position with the Fig. 2 height.

[0020] As shown in Figure 1, an embodiment of a steering column assembly 2 comprises within the Fig. 2-4, the scope of the present invention includes a two-piece steering column cover having an inner cover section 4 and an outer cover section 6. One end of the inner cover section 4 is positioned within one end of the outer cover section 6 so that the two cover sections can be telescopically adjusted to adjust the overall length of the cover. In the example shown, the outer cover section 6 is positioned farthest from the steering wheel end of the assembly 2, and the inner cover 4 is positioned closer to the steering wheel.

[0021] Within the cover is a two-part telescopic steering shaft 8, with the part closest to the steering wheel fitting around the part farthest from the steering wheel. A bearing assembly 10 supports the steering shaft 8 within the cover.

[0022] The panel is secured in a use position to the vehicle body using a clamping mechanism 12. This comprises a clamping pin passing through a hole in a feature integral with the outer panel section, as can be seen in Figure 1. This pin also passes through a Fig. 1 support bracket (not shown).

[0023] The outer trim section 6 is provided with an elongated slot 14 extending axially along the outer trim section 6. In this example, it is located on top of the trim, but it could be provided in a different position, e.g., on the side of the outer conduit section 6. The slot 14 is positioned near the end of the outer trim section 6 closest to the steering wheel. The inner trim section 4 is also provided with an elongated slot 16 extending axially along the inner trim section 4, again on top of the inner trim section 4 near the end that fits into the outer trim section 6. The two slots 14, 16 always overlap, at least in part, across the height adjustment range of the steering column assembly 2.

[0024] The assembly 2 further comprises a mushroom-shaped end stop 18 having a stem 20 extending downward through the slot 14 in the outer fairing section 6 and into the slot 16 in the inner fairing section 4. A wider head 22 of the end stop 18 prevents it from falling through the two slots 14, 16. A cover member 24 is fixed over the slot 14 in the outer fairing section 6. This comprises, as shown, a plate 26 secured by two small screws 28 engaging the outer fairing section 6.

[0025] The cover plate 26 prevents the shaft 20 of the end stop 18 from coming out of the slots 14, 16, but does not restrict the movement of the shaft 20 along the two slots 14, 16. The width of the shaft 20 is less than 10 percent of the lengths of the slots 14, 16, and the shaft 20 fits snugly into the slots 14, 16, so that it is guided along by the edges of the slots 14, 16.

[0026] In use, the end stop 18 can move freely along both slots 14, 16 when the steering column assembly 2 is positioned anywhere between the maximum retracted height position and the maximum extended height position. However, the lengths of the slots 14, 16 and their respective axial positions are selected such that when the steering assembly 2 reaches the extended height position, the stem 20 of the end stop 18 abuts one end 16a of the slot 16 in the inner fairing section 4 and one end 14a of the slot 14 in the outer fairing section 6, with the two ends 14a, 16a applying a compressive force to the stem 20. This prevents the fairing from extending beyond its extended height position. Similarly, the shaft abuts the opposite ends 14b, 16b of the two slots 14, 16 when the steering assembly 2 reaches the retracted height position.Again, these ends 14b, 16b exert a compressive force on the shaft 20.

[0027] The stem 20 is arranged to shear when the compressive force exceeds a predefined level, which is selected to be higher than the force expected during height adjustment of the fairing and lower than the force expected during a crash in which a driver impacts the steering wheel. In this case, the stem 20 shears at the interface between the outer surface 30 of the inner fairing 4 and the inner surface 32 of the outer fairing 6, where the fairing sections act on the stem 20. After shearing, further collapse of the fairing beyond the retracted height position can be achieved.

Claims

[1] A steering column assembly comprising a steering column cover having an inner cover portion (4) and an outer cover portion (6), one end of the inner cover portion (4) being positioned within one end of the outer cover portion (6) so that the two cover portions (4, 6) can be telescopically adjusted to adjust the overall length of the cover, the outer cover portion (6) being provided with an elongated slot (14) extending axially along the outer cover portion (6), and the inner cover portion (4) also being provided with an elongated slot (16) extending axially along the inner cover portion (4), the two slots (14, 16) always at least partially overlapping over the height adjustment range of the steering column assembly (2), and further comprising an end stop (18),which extends through the slot (14) in the outer trim section (6) and the slot (16) in the inner trim section (4), wherein the end stop (18) can move freely along both slots (14, 16) when the steering column assembly (2) is positioned between the position at maximum retracted height and the position at maximum extended height, and is arranged to abut one end (16a) of the inner slot (16) and one end (14a) of the outer slot (14) when the steering column assembly (2) reaches the position at extended height, and to abut the opposite ends (14b, 16b) of the two slots (14, 16) when the steering column assembly (2) reaches the position at retracted height, , characterized byin that the end stop (18) comprises a shaft (20) passing through the two slots (14, 16) and a head (22) preventing the end stop (18) from being pulled through the slots (14, 16) while allowing a sliding movement of the end stop (18). [2] A steering column assembly according to claim 1, wherein the end stop (18) comprises an elongated bracket which fits into a pair of grooves extending along the two sides of the slot (14) in the outer trim portion (6), the bracket being capable of sliding along the grooves in use. [3] Steering column assembly according to claim 2, wherein said grooves extend beyond the ends (14a, 14b) of the slot (14). [4] Steering column assembly according to one of claims 1 to 3, wherein the end stop (18) is positioned such that the head (22) is positioned on the outside of the outer trim section (6). [5] Steering column assembly according to claim 4, wherein the slots (14, 16) are provided in an uppermost region of the two trim sections (4, 6) so that the head (22) sits over the slots (14, 16) and prevents the end stop (18) from falling through the slots (14, 16). [6] Steering column arrangement according to one of claims 1 to 5, wherein the end stop (18) is held in the two slots (14, 16) by a cover member. [7] A steering column assembly according to claim 6, wherein the cover member comprises a cover plate secured to the outer trim portion (6). [8] A steering column assembly according to any one of claims 1 to 7, wherein the stem (20) of the end stop (18) is frangible so that it breaks when subjected to a high force applied from the ends (14a, 14b, 16a, 16b) of the slots (14, 16) in the event of a crash, thereby allowing the fairing sections (4, 6) to collapse beyond the retracted height position. [9] Steering column assembly according to one of claims 1 to 8, wherein the inner trim portion (4) is positioned closer to the steering wheel than the outer trim portion (6). [10] A steering column assembly according to claim 9, wherein the outer trim portion (6) is fixed to a clamping assembly which, in use, is movable between a first position in which it clamps the outer trim portion (6) to the inner trim portion (4) to prevent height adjustment and a second position in which the outer trim portion (6) is released from the inner trim portion (4) to allow height adjustment. [11] Steering column assembly according to claim 10, which is adjustable in both inclination and height.

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