Pre-Curved Backrest Linkage for Shoulder and Head Support
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Solution Overview
Problem
Existing seat designs fail to provide adequate ergonomic support for the shoulder and head areas, especially when the backrest is reclined, and lack a synchronized adjustment mechanism for seat height and backrest inclination.
Innovation Solution
A seat with a backrest support featuring a link chain made of movable links, a flexible actuator, and a return spring, allowing the backrest to assume a pre-curved deformation and synchronize with seat height adjustment, ensuring improved support and comfort through adjustable pre-curved deformation and synchronized movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the backrest is made rigid to provide stable support, then structural stability is improved, but ergonomic adaptability to user's back profile deteriorates
Solution Approach 1:
The backrest is divided into multiple rigid elements (at least three) that can move independently relative to each other around horizontal axes. This segmentation allows each element to adjust independently to different parts of the user's back profile while maintaining overall structural stability through their interconnected rigid construction.
Solution Approach 2:
The backrest elements are designed to be dynamically adjustable rather than fixed. The elements can pivot and reposition themselves in response to user movement and weight distribution, enabling the rigid structure to adapt ergonomically to different body profiles while maintaining structural integrity.
2Ease of operation
If the backrest is tilted backwards to provide reclined support, then comfort is improved, but support for shoulder and head areas deteriorates
Solution Approach 1:
The backrest is segmented into multiple elements that can tilt at different angles independently. This allows the lower elements to recline for comfort while upper elements remain more upright to support the shoulder and head areas, resolving the contradiction between reclined comfort and upper body support.
Solution Approach 2:
Different sections of the backrest have different tilt characteristics and support properties. The lower elements provide reclined comfort while the upper elements maintain a more vertical orientation for head and shoulder support, creating local quality variations that satisfy both requirements simultaneously.
3Adaptability or versatility
If the backrest uses a link chain mechanism for adjustment, then ergonomic adaptability is improved, but device complexity increases
Solution Approach 1:
The adjustment mechanism is segmented into discrete rigid elements connected by simple hinges, avoiding complex continuous adjustment mechanisms. Each element can be independently positioned, providing ergonomic adaptability through discrete steps while keeping the overall mechanism relatively simple and maintainable.
4Adaptability or versatility
If the backrest elements are articulated to allow movement, then ergonomic adaptability is improved, but structural stability deteriorates
Solution Approach 1:
The backrest is segmented into rigid elements that maintain their individual structural integrity while being articulated to each other. This segmentation allows movement between elements for adaptability while each element's rigid construction maintains overall structural stability.
Solution Approach 2:
Multiple rigid elements are merged into a unified backrest structure through articulated connections. This combining allows the elements to move relative to each other for ergonomic adaptability while functioning together as a stable unified structure that maintains overall rigidity and support.
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 solution enhances ergonomic support by allowing the backrest to pre-curve under load, providing better support for the shoulders and head, while synchronizing with seat height adjustment for improved comfort and usability.
Implementation Method 1
a) the backrest assumes a successive pre-curved deformation against the action of the load by the action of a load from a basically vertical zero position to a maximum rearward-facing tilt position; b) the backrest has a return spring for setting the backrest to the zero position in the absence of a load
Implementation Method 2
A flexible actuator with a fixed length extends from an upper fixed point, which is provided on one of the links in the upper area of the backrest support, along the backrest support to a lower fixed point
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 2A~2B
AI summary
The backrest which is designed for a seat can be adjusted to form a precurved deformation. The backrest has a rest support (40) having a link chain (41) comprising a large number of links (410, 411) which are interconnected such that they can move in relation to each other. A flexible actuating element (47) with a fixed length extends from an upper fixing point (415), which is provided on one of the links (410, 411) in the upper region of the rest support (40), along the rest support (40) to a lower fixing point. Each link (410, 411) has a driver (412) which engages in the link (411) arranged beneath it. The flexible actuating element (47) is embedded in a guide (46) which is provided on the rest support (40) and which extends from close to the upper fixing point (415) to an intermediate space which is situated in front of the lower fixing point. Means (43, 45) for displacing the actuating element (47) in the guide (46) and precurving the upper fixing point (415) with an associated link (410, 411) are provided for the purpose of adjusting the backrest. The driver (412) of the link (410, 411) which is associated with the upper fixing point (415) and engages in the next link (411) which is arranged beneath it is intended to move this next link (411) to the precurved position. The further drivers (412) within the link chain (41) serve in each case to move the coupled link (411) to the precurved position.