Door Hinge Pin Motion Control Using Shear Thickening Fluid
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Solution Overview
Problem
The slamming of doors can cause harm to individuals or pets, lock them inside, and generate unpleasant noises, while uncontrolled motion in industrial settings can damage equipment and create noise pollution.
Innovation Solution
The use of Shear Thickening Fluid (STF) in devices to control door motion by stiffening under pressure, allowing normal closure with lighter pressure and damping or stopping slamming with greater pressure or speed, with adjustable resistance through mechanisms like a shim and piston system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a door is allowed to close freely without resistance, then the door can close easily and quickly, but the door may slam causing harm, noise, and damage
Solution Approach 1:
The patent utilizes shear thickening fluid whose viscosity parameter changes dynamically based on shear rate. During normal door closure with low shear rate, the fluid maintains low viscosity allowing easy movement. When door slamming occurs with high shear rate, the fluid instantly increases viscosity to provide damping and prevent harm, thus resolving the contradiction between ease of closure and prevention of slamming harm
Solution Approach 2:
The patent employs a dynamic resistance mechanism using shear thickening fluid that adapts its damping properties in real-time based on door motion speed. The fluid transitions from a liquid-like state during normal operation to a solid-like state during impact, providing adaptive control that allows easy closure while preventing slamming
2Object-affected harmful factors
If resistance is added to control door motion, then door slamming is prevented, but the door becomes harder to close normally
Solution Approach 1:
The shear thickening fluid changes its viscosity parameter dynamically: at low shear rates during normal closure the fluid remains liquid-like with low resistance, while at high shear rates during slamming the fluid becomes solid-like with high resistance. This parameter change resolves the contradiction by providing condition-dependent resistance
3Object-affected harmful factors
If viscous fluid is used to dampen door motion, then slamming is reduced, but the door closure speed is slowed under all conditions
Solution Approach 1:
The shear thickening fluid's viscosity parameter changes based on shear rate: during normal closure with low shear rate, the fluid maintains low viscosity preserving natural closure speed; during slamming with high shear rate, the fluid instantly increases viscosity to provide damping. This resolves the contradiction between damping and closure speed by making viscosity conditional
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 STF-based systems effectively dampen door slamming and control motion, preventing harm and noise, while allowing adjustable resistance to suit various applications.
Implementation Method 1
STF is relaxed at rest and behaves nearly like most viscous liquids under minimal shear or pressure (e.g., flowable, pourable, etc.). Under normal closing conditions, the fluid remains relaxed and the door closes easily. When pressure or shear forces are applied, the fluid stiffens instantaneously
Data Source
AI summary
Systems and devices to control linear, rotational, and/or arcuate motion are provided herein. In some examples, a pin system is configured for insertion in a door and/or door jamb, and to control motion of the door, such as a speed with which the door closes. In some examples, a hinge pin is configured to replace a conventional hinge pin and to control motion of the door. In some examples, a hinge system is configured to replace a conventional door hinge and to control motion of the door.