Steering Column Lever With Plastically Deformable Stress Point

The patent introduces a predefined plastically deformable stress point with notches in the lever member second portion before impact occurs. This stress point acts as a predetermined weak location that will yield under impact forces, absorbing energy through controlled plastic deformation. The notches concentrate stress at specific locations to initiate controlled deformation rather than uncontrolled fracturing, thereby cushioning the structure against harmful impact forces while maintaining overall integrity.

The patent converts the harmful impact force that would otherwise cause catastrophic fracturing into a beneficial controlled plastic deformation process. By designing the lever member with a predefined plastically deformable stress point, the impact energy is transformed into useful work that deforms the material in a controlled manner, absorbing energy and preventing more severe structural damage to the steering column assembly.

The patent applies local quality by introducing notches only at specific locations where the lever member second portion requires controlled deformation. Rather than modifying the entire lever member structure, the notches are localized to create stress concentration points that facilitate predictable plastic deformation. This localized modification approach minimizes manufacturing complexity while achieving the desired energy absorption characteristics at critical locations.

The patent changes the physical parameters of the lever member by introducing notches that alter the stress distribution and deformation characteristics. The notches modify the geometric parameters of the lever member second portion, creating predetermined locations where plastic deformation will occur under impact. This parameter change enables controlled energy absorption without requiring complex manufacturing processes, as the notches can be formed using standard machining or forming operations.