Variable-Stiffness Cushion Infill for Prolonged Seating Comfort
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current vehicular seat cushions provide limited comfort over prolonged periods as they lock the occupant in a fixed position, preventing adjustments and movements that affect long-term comfort.
Innovation Solution
A cushion member with variable stiffness is developed, comprising a deformable and sealable housing filled with granular and hollow particles, whose internal pressure is adjusted to change stiffness states from soft to semi-rigid and intermediate, allowing conformability to occupant movements and terrain inputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the cushion housing is filled with traditional solid particles, then the cushion provides structural support, but the cushion cannot adapt to occupant movements and maintains fixed stiffness
Solution Approach 1:
The cushion housing contains a composite particle system comprising both solid particles and hollow particles. The hollow particles have compressible walls that can deform under load, providing variable stiffness. This composite material approach allows the cushion to adapt to occupant movements while maintaining structural support, resolving the contradiction between adaptability and structural integrity.
Solution Approach 2:
The cushion system changes the physical state and properties of the infill material dynamically. The hollow particles undergo compression and expansion cycles, changing their volume and stiffness characteristics in response to applied loads. This parameter change enables the cushion to transition between soft and supportive states, providing adaptability without complex mechanical mechanisms.
2Duration of action of moving object
If the cushion uses fixed stiffness material, then the cushion provides consistent support, but the cushion cannot accommodate prolonged seating comfort needs
Solution Approach 1:
The cushion transitions from a static, fixed-stiffness system to a dynamic system where the hollow particles continuously adjust their compression state. As the occupant settles into the cushion over time, the hollow particles compress and then rebound, providing ongoing adaptation. This dynamic behavior extends the duration of comfort by preventing the cushion from locking into a fixed position.
Solution Approach 2:
The hollow particles provide continuous useful action through their compression and expansion cycles. Rather than reaching a static equilibrium, the particles continuously adjust to maintain comfort, ensuring the cushion remains adaptive throughout the entire duration of seating. This continuous adjustment prevents discomfort that would otherwise occur during prolonged seating.
3Shape
If the cushion housing is made rigid, then the cushion maintains its shape, but the cushion cannot deform to conform to the occupant
Solution Approach 1:
The hollow particles act as flexible micro-shells within the cushion matrix. These thin-walled structures can deform and conform to applied pressures from the occupant's body, allowing the cushion to take the shape of the occupant. Despite this flexibility at the particle level, the collective arrangement of numerous particles maintains the overall structural integrity of the cushion housing.
Solution Approach 2:
The cushion is segmented into numerous individual hollow particles rather than being a single rigid structure. This segmentation allows each particle to independently deform and conform to local pressure points on the occupant's body, while the aggregate of all particles maintains the cushion's overall shape and structural support capabilities.
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
Enhances comfort during prolonged seating by dynamically adjusting stiffness to accommodate occupant movements and terrain conditions, providing improved support and adaptability.
Implementation Method 1
decreasing the internal pressure of the interior from the first pressure to a second pressure in response to continual contact with the occupant such that the hollow particles are compressed
Implementation Method 2
each hollow particle is compressible and hollow to define a void therein
Implementation Method 3
fluidizing the cushion infill with positive pressure to the interior such that the hollow particles and granular particles can relatively move past one another
Implementation Method 4
decreasing the internal pressure of the interior from the first pressure to a second pressure
Implementation Method 5
the hollow particles are compressed due to frictional contact and interlocked with the granular particles due to mechanical interference and friction
Data Source
AI summary
A cushion member having improved variable stiffness for a target is provided. The cushion member comprises a cushion housing having an interior with a variable internal pressure and an exterior surface for receiving the target. The cushion housing is arranged to be deformable and comprises granular particles disposed in the interior of the cushion housing. The cushion housing further comprises hollow particles disposed therein with the granular particles. Each hollow particle is compressible and hollow to define a void therein. The hollow particles have a size, a wall thickness, a material, and a bulk modulus defining infill properties thereof. The hollow particles and the granular particles are arranged to allow the cushion housing to be deformed upon contact with the target. The hollow particles and granular particles define a cushion infill having a variable stiffness based on the infill properties and the variable internal pressure of the interior.