Door Hinge Pin Motion Control Using Shear Thickening Fluid
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Solution Overview
Problem
The slamming of doors can cause injuries, equipment damage, and unpleasant noises due to uncontrolled motion, particularly in industrial settings where motion is not adequately dampened.
Innovation Solution
The use of Shear Thickening Fluid (STF) in devices that control door motion by stiffening under increased pressure or speed, allowing for adjustable resistance to prevent slamming and control the speed of door closure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a door is allowed to close freely without resistance, then the door closes easily and quickly, but the door may slam causing injury, equipment damage, and noise
Solution Approach 1:
The patent uses shear thickening fluid whose viscosity parameter changes dynamically based on shear rate. During normal closing, the fluid remains low viscosity allowing easy movement. During slamming, the high shear rate triggers viscosity increase, providing resistance. This parameter change resolves the contradiction between easy closing and slam prevention.
Solution Approach 2:
The patent implements dynamic resistance adjustment through the shear thickening fluid that adapts its properties in real-time based on the door's motion characteristics. The fluid transitions from a relaxed state during normal operation to a stiffened state during impact, creating a dynamic system that resolves the contradiction between freedom of motion and protection from harmful effects.
2Object-affected harmful factors
If resistance is increased to prevent door slamming, then the door can be controlled and damage prevented, but the door becomes difficult to close normally
Solution Approach 1:
The shear thickening fluid changes its viscosity parameter based on shear rate conditions. During normal closing operations with low shear rates, the fluid maintains low viscosity for ease of operation. During slamming conditions with high shear rates, the viscosity increases dramatically to prevent damage. This conditional parameter change resolves the contradiction between easy operation and harmful effect prevention.
Solution Approach 2:
The shear thickening fluid automatically adjusts its resistance properties in response to the door's motion characteristics without external control. The fluid self-regulates by transitioning between relaxed and stiffened states based on the applied shear forces, eliminating the need for external sensors or actuators and maintaining ease of operation while preventing slamming.
3Reliability
If shear thickening fluid is used to control door motion, then slamming is prevented and safety is improved, but the device complexity increases
Solution Approach 1:
The shear thickening fluid serves as a self-regulating component that automatically adjusts its properties based on the door's motion characteristics. The fluid transitions between relaxed and stiffened states in response to shear rate changes, providing safety and control without requiring external sensors, actuators, or control systems. This self-service approach improves reliability while minimizing device complexity.
Solution Approach 2:
The shear thickening fluid acts as an intermediary between the door and the hinge mechanism, providing motion control through its variable viscosity properties. The fluid mediates the interaction between moving and stationary components, enabling safety and control functions without requiring complex mechanical linkages or electronic control systems, thus improving reliability while keeping the device simple.
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
Effectively prevents door slamming by providing adjustable resistance, reducing the risk of injury and equipment damage while minimizing noise, and ensuring controlled motion in 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.