American Ergonomics Corporation

Innovative Seat Technology for Comfort and Safety

Optimizing the CBM Seat Design

Hector Serber
American Ergonomics Corporation
©1998 Shore-Varrone, Inc.

Optimization Methodology
Computer Model Results
Road Test Performance
Performance Summary


For safety, Dynamic Seating involves managing body posture through a path of motion that functions with both the dynamics of frontal vehicular collision and occupant biomechanics.

Upon impact, the CBM (Counter Balanced Motion) Seat dynamics positions the body toward the fetal position and the seat cushion captures the buttock as a restraining "safety net".

The CBM Seat design principle of Dynamic Seating is to center the seat motion proximate and relative to the body´s centers of mass and motion to obtain dynamic equilibrium during the pulse and stability during normal driving. (1)

During deployment, the seat travels in an upward, arcuate path which complements lumbar motion about the Instantaneous Center of Lumbar Flexion (ICLF). (2) Thus, the body rotates about it´s CG providing a defined path which reciprocally complements the seat containment characteristics to catch and decelerate the lower body.

During normal driving, the CBM Seat remains stationary with the occupant by gravity. The seat and lumbar adjust in response to occupant movements to accommodate the body.

Due to the counter balance nature of the CBM, during changes in velocity, the seat and lumbar align toward a more supportive angle, seeking equilibrium of forces.

This paper focuses on the CBM Seat design, optimization, computer crash modeling results and road performance.

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