Quarter-Turn Fastener Geometry for One-Sided Stable Assembly
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Solution Overview
Problem
Conventional twist locks are complex to assemble, inefficient in space utilization, and costly due to the need for metal materials, with a high risk of material failure under high forces due to uneven loading.
Innovation Solution
A quarter-turn fastener with a central connecting pin and guide element, allowing for pre-assembly from one side, using non-rotationally symmetrical through-openings and pivotable contact surfaces that absorb forces uniformly, and a guide element to compensate for displacement, enabling stable connections with lightweight materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional twist locks use a cross pin area and prestressing element, then the connection can be established, but the assembly becomes complex and requires significant protrusion beyond components
Solution Approach 1:
The patent removes the prestressing element (compression spring) from the conventional twist lock design. The connecting pin is inserted without any prestressing element, and the locking mechanism relies solely on the geometric interaction between the pin's contour and the receptacle's counter-contour, eliminating the need for springs and reducing assembly complexity
Solution Approach 2:
The connecting pin is divided into functionally distinct segments: a bearing pin portion for insertion, a contour portion with specific geometric features (first and second contours) for engagement, and a head portion. This segmentation allows each part to perform its specific function efficiently without requiring additional components
2Reliability
If the connecting pin and lock receptacle protrude significantly beyond components, then the connection can be established, but space utilization becomes inefficient
Solution Approach 1:
The connecting pin features a dynamic contour design where the first contour allows the pin to protrude during insertion, and the second contour (with reduced radius of curvature) enables the pin to be received within the receptacle's counter-contour upon rotation. This dynamic geometric transformation allows the connection to be established without permanent significant protrusion, improving space utilization
3Force
If the connection force is borne by the cross pin area, then the connection can be established, but only a small area ensures connection leading to high manufacturing costs
Solution Approach 1:
The patent incorporates a chamfer on the connecting pin that performs preliminary action by guiding the pin into the receptacle during insertion. This preliminary guiding action ensures proper alignment and distribution of forces before the final locking engagement, allowing the use of lighter materials and reducing manufacturing costs while maintaining connection strength
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 allows for efficient, cost-effective assembly, high force absorption, and stable connections without material failure, suitable for one-sided installation and use in various applications.
Implementation Method 1
a prestressing element, usually a compression spring
Implementation Method 2
Both the insertion of the connecting pin into the closure receptacle and the rotation of the rotary closure take place against the spring force of the pretensioning element
Data Source
Figure 1a~2b
Figure 2c~3d
Figure 4a~4d
AI summary
The invention relates to a rotary closure for the detachable connection of two plate-shaped components (1, 2, 3), each of which has a through-opening, wherein one of the through-openings (3b) is not rotationally symmetrical. The rotary closure has a closure element (10) comprising a first contact surface (11), a second contact surface (12), and a connecting pin (13) rotatable about an axis of rotation (14). The connecting pin connects the two contact surfaces (11, 12) at a distance from each other and is centrally connected to the first and second contact surfaces (11, 12), with the contact surfaces (11, 12) projecting radially away from the axis of rotation. The rotary closure additionally has a guide element (20) with a guide channel (21) in which the connecting pin (13) is rotatably mounted.One of the contact surfaces (11, 12) can be pivoted from a mounting position to a locking position, wherein the contact surface (11, 12) lies within an envelope defined by the non-rotationally symmetrical through-opening (3b) in the mounting position and outside the envelope in the locking position. A projection (18) can be formed on the locking element (10) and/or the guide element (20) which engages in a recess (27).