Blind-Side Bolt Connection with Expanding Washer Lock
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Solution Overview
Problem
Existing connection systems fail to effectively mount bolts and similar connecting elements on surfaces that are not accessible from the rear, such as concrete, wood, or machine parts, often requiring hazardous welding or inadequate dowel mechanisms.
Innovation Solution
A connection system comprising a hole bushing, bolt, nut, and washer, where the washer opens to secure the bolt in place with a rotary movement, allowing attachment on inaccessible surfaces through a mechanism that includes turning mechanisms and interference fits to lock the bolt in position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional bolts and nuts are used for connection, then strong connecting force is achieved, but the rear surface must be accessible for nut attachment
Solution Approach 1:
The patent introduces a hole bushing as an intermediary component inserted into the hole on the inaccessible surface. The hole bushing provides internal threads for nut attachment from the front side, eliminating the need to access the rear surface. This mediator transfers the connection function from the inaccessible rear surface to the accessible front surface.
Solution Approach 2:
Instead of attaching the nut from the rear surface (traditional method), the invention inverts the approach by providing thread engagement from the front surface through the hole bushing. The connection sequence is reversed: the bolt is inserted from the front, the hole bushing is placed on the bolt, and the nut is attached from the front rather than from the back.
2Strength
If welding is used to connect parts on inaccessible surfaces, then strong connection is achieved, but safety hazards and health risks increase
Solution Approach 1:
The patent replaces the thermal welding process with a mechanical fastening system consisting of hole bushing, bolt, and nut. This mechanical substitution eliminates the safety hazards and health risks associated with welding (heat, sparks, fumes) while providing equivalent or superior connection strength through controlled mechanical forces.
Solution Approach 2:
The hole bushing is designed as a sacrificial, easily replaceable component that protects the main structural parts from direct fastening operations. Instead of welding or directly fastening to valuable structural components, the inexpensive hole bushing serves as the connection interface, reducing risks to the primary structure.
3Ease of operation
If dowel mechanisms are used for inaccessible surfaces, then installation is simplified, but connection reliability is insufficient
Solution Approach 1:
The invention segments the connection system into distinct functional components: the hole bushing (providing thread engagement), the bolt (providing clamping force), and the nut (providing locking). This segmentation allows each component to be optimized for its specific function while maintaining overall reliability, unlike monolithic dowel mechanisms.
Solution Approach 2:
The hole bushing features a cylindrical geometry that provides precise alignment and uniform load distribution. The circular cross-section of the hole bushing and bolt creates optimal stress distribution patterns, enhancing connection reliability compared to non-cylindrical dowel mechanisms.
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 secure and efficient attachment of connecting elements on surfaces with inaccessible rear sides, eliminating the need for hazardous welding and providing a reliable, easy-to-use solution for various materials like metal, concrete, and wood.
Implementation Method 1
the washer opens to secure the bolt in place with a rotary movement
Implementation Method 2
turning mechanisms and interference fits to lock the bolt in position
Implementation Method 3
turning mechanisms and interference fits to lock the bolt in position
Implementation Method 4
turning mechanisms and interference fits to lock the bolt in position
Data Source
AI summary
A connection system including a connection hole inserted in form of a circular hole on the part to be connected, a cylindrical hole bushing engages into the connection hole and has a screw hole thereon vertical to the surface of the part to which it is placed, a bolt is placed on the hole bushing such that the head part remains on the lower surface of the part or inside the part, a nut attached at the bolt end extending outwards the part, a washer formed of a circular base is placed between the head part and the hole bushing, a rib extends vertically over the base and is folded by compressing between the head part and the hole bushing, and prevents the head part from passing through the connection hole, and enabling two or more parts to be connected.