Expansion Bolt Clamping Ring for High-Force Tightening in Tight Spaces
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Solution Overview
Problem
Existing expansion bolts require cumbersome tools and time-consuming processes for loosening, especially in restricted installation spaces, and struggle to apply sufficient clamping force without machine tools, particularly for larger diameters.
Innovation Solution
The expansion bolt features a tapered cone section and inner cone contour with a clamping flange and a clamping device comprising a clamping ring and pressure bolts that apply axial force, allowing for adjustable expansion and high clamping forces without external threads or machine tools, simplifying both tightening and loosening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a conventional expansion bolt with external thread and lock nut is used, then high clamping force can be achieved, but loosening requires cumbersome extraction tools and time-consuming processes
Solution Approach 1:
The invention inverts the conventional expansion bolt design by moving the external thread from the lock nut to the expansion sleeve itself. This allows the sleeve to be directly screwed out of the blind hole using a simple thread engagement, eliminating the need for complex extraction tools. The cone section and inner cone contour maintain the expansion function while the threaded sleeve enables straightforward removal.
Solution Approach 2:
The invention extracts the external threading function from the lock nut component and relocates it to the expansion sleeve. This separation allows the sleeve to serve dual purposes: maintaining expansion through the cone mechanism and enabling direct extraction through its external thread, thereby simplifying the loosening process.
2Force
If hydraulic or machine clamping tools are used to apply high clamping force, then sufficient tightening force can be achieved, but the installation space requirement increases and tool complexity increases
Solution Approach 1:
The invention employs a dynamic expansion mechanism where the cone section and inner cone contour work together to convert axial tightening force into radial expansion force. This mechanical advantage system allows manual tightening to generate sufficient clamping force that would otherwise require hydraulic tools, while keeping the device structure simple and suitable for restricted installation spaces.
Solution Approach 2:
The invention changes the geometric parameters of the cone section and inner cone contour to optimize the mechanical advantage ratio. By carefully designing the cone angles and dimensions, the system amplifies the input tightening force to produce the required high clamping force on the assembly parts, eliminating the need for complex machine tools.
3Stress or pressure
If the expansion sleeve is widened by pressing against the cone section, then radial pressure can be introduced into the assembly hole wall, but the gap width must be precisely controlled
Solution Approach 1:
The invention incorporates a gap between the lock nut and the outer side of the second assembly part before tightening begins. This preliminary gap serves as a built-in adjustment mechanism that automatically controls the expansion degree. As the sleeve is tightened against the cone section, the gap closes first, providing a natural stop that prevents over-expansion and ensures consistent radial pressure without requiring precise gap width control during manufacturing.
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
This design enables efficient and simplified tightening and loosening of expansion bolts, even in constricted spaces, by distributing clamping force through multiple pressure bolts, reducing the required torque and eliminating the need for hydraulic tools, while maintaining high clamping force.
Implementation Method 1
By moving the expansion sleeve in relation to the bolt in the axial direction, the former can be widened. The cone section is tapered facing away from the anchoring means of the bolt. The tapering is thus executed in the direction toward the orifice of the blind hole.
Implementation Method 2
The radial pressure, which is introduced via the expansion sleeve into the wall, enclosing the assembly hole, of the two assembly parts to be clamped
Implementation Method 3
a bolt having an end-face anchoring means for the tension-resistant anchoring of the bolt on or in a first assembly part, which bolt comprises a truncated-cone-shaped cone section and a bolt threaded section, in its end section opposite to the anchoring means, having a nut screwed thereon
Data Source
AI summary
An expansion bolt comprises a bolt having an end-face anchoring means for the tension-resistant anchoring of the bolt on or in a first assembly part, which bolt has a truncated-cone-shaped cone section and a bolt threaded section in its end section opposite to the anchoring means with a nut screwed thereon, an expansion sleeve having a cylindrical lateral surface and an inner cone contour interacting with the cone section of the bolt, and a clamping device supported on a second assembly part for widening the expansion sleeve and applying an axial clamping force to the assembly parts to be connected together. The cone section of the bolt is tapered in the direction toward its anchoring means and the inner cone contour of the expansion sleeve is tapered in the same direction. The expansion sleeve bears a clamping flange protruding outward in the radial direction on its end opposite to the inner cone contour. The clamping device comprises a clamping ring having an axial passage opening. The expansion sleeve engages through this passage opening, permitting an adjustability of the expansion sleeve in relation to the clamping ring in the axial direction, and protrudes with its clamping flange beyond a peripheral region of the clamping device enclosing the passage opening. The clamping ring also comprises multiple pressure bolts arranged circumferentially distributed, which mesh with their thread in internally threaded holes extending through the clamping ring in the axial direction and act with their bases indirectly or directly against the second assembly part to widen the expansion sleeve and apply an axial clamping force to the assembly parts. Furthermore, a connection assembly having such an expansion bolt is described.