Stud-Connector Frustoconical Rivet Fixing Stability

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Solution Overview

Problem

Existing stud-connector systems for connecting concrete to iron beams face issues with imperfect fixings between rivets and connectors, leading to stability problems due to potential transverse movement of rivets, which can compromise the structural integrity of the finished works.

Innovation Solution

The stud-connector features frustoconical holes for rivet insertion and matching frustoconical sections on the rivet shanks near their heads, ensuring a stable fit, along with a double frustoconical contact area between the rod and plate for enhanced fastening, preventing any oscillation or sliding, and utilizing a zigzag plate for additional support.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cylindrical holes and cylindrical rivet shanks are used for connection, then the manufacturing and insertion process is simple, but the fixing stability is insufficient due to potential transverse movement of rivets

Engineering Contradiction:
Improvefixing stabilityVSAvoidconnector structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating frustoconical surfaces specifically at the contact zones between rivets and holes, and between rod and plate. This localized conical geometry provides enhanced friction and mechanical interlocking precisely where needed for stability, while the rest of the components remain simple cylindrical forms for ease of manufacture.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the geometric parameter of the connection interface from cylindrical to frustoconical. This parameter change increases the contact surface area and creates a wedging effect that prevents transverse movement of rivets, thereby improving fixing stability without significantly complicating the overall device structure.

Inventive Principle:
Principle #35Parameter changes

2Strength

If electrical welding is used to mount connectors on beams, then the connectors can be firmly attached, but the operation is complex and prone to structural problems

Engineering Contradiction:
Improveconnection strengthVSAvoidmounting operation ease
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent replaces the electrical welding process with a mechanical fastening system using rivets. This substitution eliminates the complexity and structural risks associated with welding operations while maintaining strong connections through the frustoconical mechanical interlocking mechanism.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces rivets as intermediary elements between the connectors and the beam flange. These rivets provide a reliable mechanical connection that is easier to execute than welding, while the frustoconical geometry ensures they remain firmly in place during the concrete pouring process.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a zigzag-shaped plate is interposed between the rod and beam flange, then additional support and stability are provided, but the device complexity increases

Engineering Contradiction:
Improvestructural stabilityVSAvoidconnector assembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent creates a composite connection system by combining the rod, plate, and rivets into an integrated assembly. The zigzag-shaped plate acts as a structural element that distributes loads and enhances stability, creating a composite structure that provides superior performance compared to simple direct attachment.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP1710364B1Stud-connector for the connection of a concrete casting onto an iron beam
Publication Date: 2009.01.21 TECNARIA
  • EP1710364B1 patent drawingFigure 1~5
  • EP1710364B1 patent drawingFigure 6
  • EP1710364B1 patent drawingFigure 7

AI summary

This relates to a stud-connector adapted to permit the connection of a concrete casting onto iron beams, of the type comprising a cylindrical section rod (1), equipped with an upper head (2) of greater diameter, whose opposite end is fixed to a shaped plate (3), equipped with a pair of holes (7, 8) adapted to permit the passage of the shanks of rivets (9, 10), on which the concrete casting is subsequently carried out. The device is characterised for the fact that said holes (7, 8) have a frustoconical conformation, with smaller portion turned downward, as an analogous conformation is foreseen at the sections (9', 10') of the rivets closest to the heads (9" , 10") of the aforesaid. This permits obtaining a stable contact between said rivets and the inner walls of the holes wherein they are inserted, so to avoid the possibility of even minimal sliding in transverse direction of the heads of the rivets themselves.