Vehicle Seatbelt Tether Ring Headrest Positioning
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Solution Overview
Problem
Existing vehicle seatbelt assemblies do not effectively draw the upper portion of the seatbelt toward the headrest portion in response to tensioning events, such as rapid deceleration or impacts, which can lead to inadequate restraint of the passenger's upper torso.
Innovation Solution
A seatbelt tether assembly with a tensioning mechanism, an elongated connecting portion, and a tether ring, where the tensioning mechanism applies tension to the elongated connecting portion and tether ring upon detection of a tensioning event, causing the tether ring to move from an outboard position to a position closer to the headrest, thereby pulling the seatbelt toward the headrest for improved restraint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the seatbelt is configured to extend over the passenger's shoulder area, then the seatbelt can provide basic restraint coverage, but the upper portion of the seatbelt cannot be effectively drawn toward the headrest during tensioning events
Solution Approach 1:
The seatbelt assembly is divided into functional segments: the seatbelt itself, the tether ring, the elongated connecting portion, and the tensioning mechanism. This segmentation allows the upper portion of the seatbelt to be independently controlled and drawn toward the headrest during tensioning events, improving restraint effectiveness without requiring a complete redesign of the entire seatbelt system.
Solution Approach 2:
The tether ring acts as an intermediary component between the seatbelt and the tensioning mechanism. It receives the seatbelt, allows it to slide through, and connects to the elongated connecting portion that transmits tensioning forces. This intermediary structure enables the seatbelt to be drawn toward the headrest while maintaining flexibility and ease of movement during normal operation.
2Ease of operation
If the tether ring is positioned at the upper outboard side of the seatback portion, then the seatbelt has freedom of movement during normal operation, but the seatbelt cannot be pulled toward the headrest during tensioning events
Solution Approach 1:
The tether ring is designed to be dynamically positionable along the elongated connecting portion. During normal operation, it remains at the upper outboard side allowing free movement. During tensioning events, the tensioning mechanism draws the elongated connecting portion, which in turn pulls the tether ring toward the headrest. This dynamic repositioning provides both ease of operation and reliable upper torso restraint.
Solution Approach 2:
The position parameter of the tether ring is changed based on operational conditions. In the normal state, the tether ring is positioned at the upper outboard side for freedom of movement. During tensioning events, the position parameter changes as the tether ring is drawn toward the headrest, transforming the restraint geometry to improve upper torso support.
3Reliability
If a tensioning mechanism is added to draw the seatbelt toward the headrest, then upper torso restraint is improved, but the device complexity increases
Solution Approach 1:
The tensioning mechanism is integrated with existing seatbelt assembly components. The elongated connecting portion connects the tether ring to the tensioning mechanism, merging these functions into a cohesive unit that works with the existing seatbelt structure. This integration approach improves upper torso restraint while minimizing the increase in overall device complexity.
Solution Approach 2:
The tensioning mechanism is designed to work with the existing seatbelt system architecture, serving multiple functions: it draws the upper portion of the seatbelt toward the headrest during tensioning events, maintains proper seatbelt positioning during normal operation, and integrates with the existing buckle and retractor systems. This multi-functionality reduces the need for separate dedicated components.
Data Source
AI summary
A seatback portion has a tether passageway defined therein from proximate an upper section to proximate a lower section thereof. A seatbelt tether includes a tensioning mechanism, a tether ring and a connecting portion that extends from the tether ring to the tensioning mechanism. The connecting portion extends through the tether passageway with the tether ring located at the upper section outside the seatback portion. The tether ring is shaped and dimension to slide-ably receive a seatbelt. The tensioning mechanism selectively applies tension to the tether ring. In a non-tensioned state the tether ring is movable to an upper outboard side of the seatback portion. In a tensioned state the tether ring is pulled toward a headrest supporting section of the seatback portion inboard and away from the upper outboard side of the seatback portion.