Seat Height Actuator Brake-Clutch Locking Against Vibration Creep
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Solution Overview
Problem
Existing seat height adjustment mechanisms in vehicles often feature complex, costly, and prone-to-failure manual actuators that can creep or unlock due to vibrations, leading to undesirable seat movement during vehicle operation.
Innovation Solution
A seat height adjustment actuator comprising a pinion, brake drum, clutch drum, and anti-creep insert, where the pinion is locked and unlocked via a driver cam and rolling brake elements, with crimp-on tabs and centering bias elements ensuring secure assembly and preventing unwanted movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If manual actuators are used for seat height adjustment, then the mechanism can be operated without power, but the actuator becomes complex, costly, and prone to failure
Solution Approach 1:
The patent replaces complex manual mechanical actuators with a simplified motorized system. The motor-driven pinion gear directly engages with the rack to adjust seat height, eliminating the need for complex cam mechanisms, springs, and levers found in traditional manual actuators. This substitution reduces part count and complexity while maintaining adjustment functionality.
2Extent of automation
If manual actuators are used for seat height adjustment, then the mechanism can be operated without power, but the actuator is heavy and large
Solution Approach 1:
The motorized pinion gear system replaces heavy manual actuator components such as stamped steel housings, multiple springs, and complex linkages. The electric motor and gear assembly are significantly lighter while providing the same height adjustment function, reducing overall seat mechanism weight.
3Extent of automation
If manual actuators are used for seat height adjustment, then the mechanism can be operated without power, but the actuator is prone to creeping or unlocking due to vibrations
Solution Approach 1:
The motorized system with pinion-rack engagement eliminates the creeping and unlocking issues inherent in manual actuators. The motor provides controlled, consistent force to maintain seat position, and the gear engagement geometry prevents backward movement under vibration loads that would cause creeping in manual systems.
Solution Approach 2:
The motorized actuator system self-regulates to maintain seat height position without requiring additional locking mechanisms or anti-creep features. The control system monitors and adjusts motor output to counteract vibrations and external forces, automatically preventing position drift that would occur in manual systems.
4Ease of operation
If complex manual actuators are used, then seat height adjustment is possible, but the production cost increases
Solution Approach 1:
Replacing complex manual actuator assemblies with a motorized pinion-rack system reduces manufacturing costs through fewer parts, simplified assembly procedures, and reduced material requirements. The elimination of multiple stamped components, springs, and adjustment mechanisms lowers both material and labor costs in production.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The actuator provides reliable, vibration-resistant seat height adjustment by locking the pinion in the absence of input and unlocking it with precise control, minimizing creep and maintaining the seat's position effectively during vehicle operation.
Implementation Method 1
a brake hub, brake drum and anti-creep insert in an assembled configuration. The rolling brake elements are disposed between the brake hub and brake drum
Implementation Method 2
biasing brake elements. The rolling brake elements are disposed between the brake hub and brake drum, with the biasing brake elements disposed between the rolling brake elements
Implementation Method 3
The actuator includes a pinion, brake drum, clutch drum and anti-creep insert
Implementation Method 4
The actuator includes a pinion, brake drum, clutch drum and anti-creep insert in an assembled configuration
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
A seat height adjustment actuator includes a brake drum fixable to a seat and defining an outer brake race. A rotatable brake hub includes a floor with a shelf, and a wall around the floor with cam surfaces defining an inner brake race. A pinion fixed to the brake hub engages a seat adjustment mechanism through the brake drum. Rolling brake elements wedge between the inner and outer brake races to lock the brake hub at rest. A clutch drum defines an outer clutch race, and includes tabs extending between the brake races to displace the brake rollers, unlocking the brake hub, under actuator input. A centering bias element on the floor simultaneously engages the shelf and a projection of the clutch drum for centering the projection over the shelf at rest. A driver cam receives actuator input and drives rotation of the clutch drum.