Expansion Anchor Sleeve With Deformable Legs for Controlled Load Holding
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Solution Overview
Problem
Existing expansion anchors, both plastic and metal, struggle to securely anchor loads of medium to high weight, lack user confirmation of complete fitting, and can cause damage due to uncontrolled expansion.
Innovation Solution
An expansion anchor with deformable legs having offset attachment portions and controlled deformation, featuring a tubular sleeve and deformable legs with varying rigidity, ensuring secure engagement and preventing pressure points on the tightening screw.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal expansion anchors are used to anchor larger loads, then load capacity is improved, but the risk of damage to the anchor and surface increases due to uncontrolled expansion
Solution Approach 1:
The patent changes the physical state and mechanical properties of the deformable legs by varying their cross-sectional dimensions along the length. The legs have a maximum width at an intermediate position and taper towards both ends, creating controlled deformation zones that manage expansion forces and prevent damage to the anchor and surface.
Solution Approach 2:
The deformable legs are divided into distinct segments with different structural characteristics - a wider intermediate section for controlled deformation and narrower end sections for reduced stress concentration. This segmentation allows different parts of the leg to perform different functions during expansion.
2Strength
If expansion anchors are tightened to secure loads, then anchoring strength is improved, but overtightening causes damage to the surface and anchor
Solution Approach 1:
The deformable legs are pre-configured with specific geometric dimensions and material properties that define their deformation characteristics before installation. This preliminary design ensures that during tightening, the legs deform in a controlled manner along predetermined paths, preventing sudden failures or overtightening damage.
Solution Approach 2:
The narrower end sections of the deformable legs act as cushioning zones that absorb excess tightening forces. These sections deform first and provide a mechanical buffer that prevents the transmission of damaging forces to the anchor body and surrounding surface, effectively cushioning against overtightening.
3Strength
If expansion tabs are moved radially outward to anchor loads, then retention force is improved, but pressure points are generated on the tightening screw thread
Solution Approach 1:
The patent modifies the geometric parameters of the deformable legs, specifically varying the width along their length with maximum width at an intermediate position. This parameter change redistributes the expansion forces away from the screw thread area, reducing pressure points while maintaining adequate retention force through the wider intermediate sections.
4Strength
If deformable legs are made more rigid to increase load capacity, then strength is improved, but controlled deformation becomes difficult
Solution Approach 1:
The deformable legs exhibit local quality variations in their structural properties along their length. The intermediate section has greater width and rigidity for load-bearing, while the end sections have reduced width for controlled deformation. This local differentiation allows the single component to simultaneously provide both strength and controlled deformability without increasing overall device complexity.
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 load capacity and mechanical stability while providing user confirmation of secure fitting, reducing the risk of damage to the anchor and the surface.
Implementation Method 1
at least one deformable leg extending between and attached to the body portion and to the expansion portion of the tubular sleeve, wherein the width of the proximal segment increases towards the proximal end of the tubular sleeve
Implementation Method 2
a tightening screw configured to move the expansion portion along the longitudinal axis inside the expansion tabs so as to expand the tabs radially outwardly relative to the longitudinal axis
Implementation Method 3
The anchoring tabs are moved apart until they are positioned into abutment against the inside surface (i.e. hole) of the wall, securing the anchor into the hole in the wall using friction and using mechanical locking
Data Source
Figure 1(A)~1(B)
Figure 2(A)~2(B)
Figure 2(C)
AI summary
The present invention relates to an expansion anchor (110). The expansion anchor comprises: a tubular sleeve (116) having a longitudinal axis and comprising an expansion portion (122) at a distal end and a body portion (118) at a proximal end and expansion tabs (124) attached to said body portion and extending towards said distal end; a tightening screw (128) configured to move said expansion portion along said longitudinal axis inside said expansion tabs so as to expand said tabs radially outwardly relative to said longitudinal axis; and at least one deformable leg (126) extending between and attached to said body portion and to said expansion portion of said tubular sleeve, said deformable leg comprising at least two coupled segments, a distal segment (126b), having a first attachment portion linking said distal segment to said expansion portion and a proximal segment (126a), having a second attachment portion linking said proximal segment to said body portion, wherein the width of said proximal segment increases towards said proximal end of said tubular sleeve.