Buckling control assembly for a steering column energy absorption strap assembly

#The embodiments disclosed herein relate to vehicle steering column assemblies and, more particularly, to a buckling control assembly for a steering column energy absorption strap assembly.

#On adjustable steering columns, energy absorption straps are utilized to partially reduce an occupant's kinetic energy during a collapse event of the steering column. Some steering columns include multiple energy absorbing straps to have a constant running load during a collapse event. Such straps may include one strap that is nested within the other strap. Prior efforts utilize an outer energy absorption strap that is fully captured on either side of the outer strap for the entire length of the collapse event, such as the generically shown design in FIG. 1. During the collapse event, either or both straps buckle because of the design properties of the strap(s). During the bucking action, the straps can bind against one another due to the lack of freedom caused by the outer strap being completely captured. The binding of the strap, or straps, undesirably results in an inconsistent running load performance.

#According to one aspect of the disclosure, a buckling control assembly for a steering column energy absorption strap assembly is provided. The buckling control assembly includes an inner energy absorption strap operatively coupled to a steering column jacket. Also included is an outer energy absorption strap surrounding at least a portion of the inner energy absorption strap and operatively coupled to the steering column jacket. Further included is a strap constraining structure disposed on a constraint side of the outer energy absorption strap to inhibit buckling of the outer energy absorption strap in a first direction, the outer energy absorption strap having a free side unconstrained to accommodate buckling of the outer energy absorption strap.

#The subject matter that is regarded as the subject invention is particularly pointed out and distinctly claimed in the claims at the conclusion of this specification. The foregoing and other features and advantages of the invention are apparent from the following detailed description of non-limiting exemplary embodiments of the invention taken in conjunction with the accompanying drawing thereof in which:

#FIG. 1 is an energy absorption strap assembly known in the art;

#FIG. 2 is an elevational, partial cross-sectional view of a steering column assembly with an energy absorption strap assembly;

#Referring now to the Figures, wherein like numerals indicate corresponding parts, the subject invention is described below with reference to specific non-limiting embodiments thereof. The embodiments described herein relate to a buckling control assembly for an energy absorption strap assembly associated with a steering column (also referred to herein as a “steering column assembly”). The steering column may be utilized in numerous types of vehicles.

#Referring to FIG. 2, the steering column is illustrated and generally referenced with numeral 10. The steering column 10 substantially extends along a longitudinal axis “A.” The steering column 10 is adjustable in a telescopic direction parallel to the longitudinal axis “A” (i.e., the steering column 10 is axially adjustable along the longitudinal axis “A”). More specifically, the steering column includes a steering shaft 12 rotatably disposed within a column assembly that includes an upper jacket 14 and a lower jacket 16. The steering shaft 12 may be one of a plurality of operatively coupled steering shafts in some embodiments. A steering wheel (not shown) is configured to be mounted to the steering shaft 12. The column jackets 14, 16 and the steering shaft 12 substantially extend along the longitudinal axis “A.” The upper jacket 14 is movable, relative to the lower jacket 16, during a normal operating condition of the vehicle to telescopically adjust a position of the steering wheel along the longitudinal axis “A.” The normal operating condition (also referred to herein as a first condition of the steering column) is defined as a normal driving condition that allows adjustment of the upper jacket 14 over a predefined range of telescoping movement that is suitable for driving.

#The steering column 10 is also operable in a second operating condition defined as a collapse of the upper jacket 14 during an energy absorption event. In this way, energy-absorbing movement (i.e., energy absorbing collapsibility) of the upper jacket 14 along the longitudinal axis “A” within the lower jacket 16 is provided. To assist with a collapse event and to provide desirable characteristics during the normal operating condition, an energy absorption strap assembly is provided, as described herein. The energy absorption strap assembly is generally referenced with numeral 20.