Spring-Loaded Temporary Fastener for Adjustable Clamping Force
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Solution Overview
Problem
Existing temporary fastening systems in manufacturing, such as those used in aircraft assembly, lack the ability to accurately apply a range of clamping forces and are often not ergonomic, making it difficult to check for gaps between panels and substructures before permanent fastening.
Innovation Solution
A system comprising a temporary fastener with a spring-mounted stem and a linear actuator that applies a predetermined clamping force by compressing the spring, allowing for adjustable force application and ergonomic use, using a spring locking device to maintain the clamping force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a hexagonal bolt with torque wrench is used as temporary fastener, then the fastening force can be applied, but the torque applied can be larger than the required range of clamping force, making it unsuitable for applications requiring specific clamping force ranges
Solution Approach 1:
The patent employs a spring-based mechanism that allows dynamic adjustment of clamping force. The spring can be compressed to different degrees, enabling the temporary fastener to provide varying levels of clamping force (25 lbs, 75 lbs, 100 lbs, etc.) depending on the specific application requirements, thus resolving the contradiction between applying force and maintaining adaptability across different force ranges
Solution Approach 2:
The invention changes the physical parameter of the spring compression to control clamping force. By adjusting the compression distance of the spring, the system can precisely control the clamping force output, allowing adaptation to different required force levels without exceeding them, thereby solving the limitation of fixed torque application
2Ease of manufacture
If a Cleco fastener is used as temporary fastener, then the fastening can be applied, but the spring force is fixed at a particular rating (e.g., 25 lbs) and is not adjustable, making it unsuitable for applications requiring a range of clamping forces
Solution Approach 1:
The patent transforms the static spring mechanism of traditional Cleco fasteners into a dynamic system where the spring compression can be varied. This allows the same simple spring-based construction to provide multiple clamping force levels by adjusting the compression amount, maintaining ease of manufacture while gaining adjustability
Solution Approach 2:
The invention makes a single spring-based fastener design capable of serving multiple force requirements. By allowing variable compression, one fastener type can replace multiple fixed-force fasteners (25 lbs, 75 lbs, 100 lbs ratings), achieving universality while maintaining the simplicity of spring-based construction
3Adaptability or versatility
If a push pull gage is used to apply clamping force, then a range of forces can be applied by hand, but the approach does not generate accurate clamping forces and is not ergonomic
Solution Approach 1:
The spring-based temporary fastener is self-regulating, providing precise clamping force through its mechanical design. The spring's physical properties and compression distance determine the force output, eliminating the need for manual estimation and providing accurate, repeatable force application without requiring complex measurement instruments
Solution Approach 2:
The spring acts as an intermediary mechanism between the user's manual input and the clamping force applied to the workpiece. This mechanical mediator translates simple compression motion into precise, controlled clamping force, improving both accuracy and ergonomics compared to direct manual force application
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 accurate and adjustable clamping force application, ensuring effective gap detection between panels and substructures, improving the quality control process and reducing ergonomic strain.
Implementation Method 1
a spring mounted about the stem; and a linear actuator configured to apply a force on the spring, thereby causing the spring to be compressed against the assembly and apply a predetermined clamping force to the assembly
Implementation Method 2
a spring locking device configured to secure the spring in a compressed state to maintain the predetermined clamping force
Data Source
AI summary
An example system includes: an apparatus comprising: a temporary fastener having a stem configured to be inserted through as assembly and be retained to the assembly, and a spring mounted about the stem. The system also includes a linear actuator configured to apply a force on the spring, thereby causing the spring to be compressed against the assembly and apply a predetermined clamping force to the assembly.