Vehicle Seat Headrest Linkage With Spindle Drive for Quiet Adjustment
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Solution Overview
Problem
Existing headrest adjusting mechanisms for vehicle seats are either difficult to manually adjust, lack comfort, and face challenges with motorized installations due to space constraints and sound insulation issues.
Innovation Solution
A four-joint gear mechanism with a spindle drive and cam guiding system that allows for vertical and longitudinal adjustment of the headrest, providing a compact, self-locking, and soundproof design with flexible spindles for enhanced strength and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a motorized adjusting mechanism is installed in the headrest, then the ease of operation is improved, but the device complexity and installation space requirements increase
Solution Approach 1:
The patent combines the longitudinal adjusting mechanism and vertical adjusting mechanism into a single integrated adjusting device. The holding device serves as a common mounting structure for both spindle drives, and the backrest fastening provides a unified attachment point to the backrest. This merging reduces overall device complexity and installation space while maintaining motorized operation for both adjusting directions.
Solution Approach 2:
The holding device performs multiple functions: it serves as the mounting structure for the longitudinal adjusting mechanism, the attachment point for the vertical adjusting mechanism, and the structural element that transfers loads between the headrest and backrest. The backrest fastening similarly provides universal attachment and load transfer functions for both adjusting directions.
2Ease of operation
If motors are installed in the headrest for motorized adjustment, then the ease of operation is improved, but noise and sound insulation issues arise
Solution Approach 1:
The patent extracts the motors from the headrest structure and relocates them to the backrest side, specifically mounting the spindle drives on the backrest fastening or holding device. This separation removes the noise-generating motors from the headrest area, eliminating sound insulation issues while preserving motorized adjusting functionality.
3Strength
If a four-joint gear mechanism with cam guiding is used, then the strength and crash safety are improved, but the device complexity increases
Solution Approach 1:
The patent segments the adjusting mechanism into distinct functional components: the four-joint gear mechanism handles longitudinal adjustment with secure guiding, while the spindle drive with cam guiding handles vertical adjustment with self-locking. Each segment is optimized for its specific function, allowing the complex mechanisms to work independently and reduce overall system complexity through functional separation.
Solution Approach 2:
The holding device serves as an intermediary structure between the backrest fastening and the headrest. It provides the mounting point for both adjusting mechanisms and the vertical adjusting spindle, while also serving as the structural element that receives and transfers loads. This intermediary structure organizes the complex mechanisms and simplifies their integration.
4Stability of the object's composition
If the front and rear guiding arms are made unequal in length, then the rigidity and strength are improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent explicitly employs asymmetric design in the four-joint gear mechanism by making the front guiding arm and rear guiding arm of unequal lengths. The front guiding arm has a different length than the rear guiding arm, creating an asymmetric linkage that provides mechanical advantage and improved rigidity for the longitudinal adjusting function.
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
Enables safe, easy, and space-efficient motorized adjustment of the headrest with high strength and crash safety, while minimizing noise and installation space requirements, resulting in improved comfort and functionality.
Implementation Method 1
The spindle drive provides self-locking, a compact design with low weight as well as high reduction ratio
Implementation Method 2
The spindle drive in combination with the cam guiding in the front guiding arm enables a suitable conversion of the linear adjusting of the spindle into the pivoting motion of the four-joint gear
Implementation Method 3
The four-joint-gear mechanism provides a secure guiding with a degree of freedom that adjusts the holding device in longitudinal direction
Implementation Method 4
a guiding means for the lower spindle end or spindle head of the spindle is provided in the holding device, whereby loads on the spindle, in particular in X direction, can at least be reduced
Data Source
AI summary
The present disclosure relates to an adjusting device for a headrest of a vehicle seat, the adjusting device comprising: a backrest fastening for attaching to a backrest, a holding device with a vertical adjustment means for adjusting the headrest in vertical direction, a longitudinal adjusting means for adjusting the holding device in a longitudinal direction, the longitudinal adjusting means comprising a four-joint gear provided between the backrest fastening and the holding device, the four-joint gear comprising two guiding arms.Here, the longitudinal adjusting means comprises a spindle drive, the spindle drive being provided between the holding device and one of the guiding arms. The guiding arm is preferably a front guiding arm. A spindle of the spindle drive is preferably translationally displaceable and provided in an arc-shaped slot guiding of the guiding arm. Moreover, a vertical adjustment by a second spindle drive is provided.