Tower Crane Module Joint With Flat-Base Stress Distribution

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Solution Overview

Problem

Existing coupling methods for tower crane structural sections, such as those using bolts or screws through bushings, suffer from reliability issues due to precise alignment requirements and potential weld defects, leading to assembly delays and structural risks.

Innovation Solution

A structural section with an attachment joint that includes a flat base and connection block, reinforced by transverse and vertical plates, distributing stress through screwing and providing greater contact surface for improved reliability and assembly control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If screw bushings are welded to join structural sections, then assembly is simplified, but reliability deteriorates due to weld defects and alignment precision requirements

Engineering Contradiction:

Improveassembly simplicityVSAvoidjoint reliability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The joint system is divided into separate functional components: a connection plate welded to the structural section, and a separate attachment piece with screw bushings. This segmentation allows the welding operation to be performed on robust plates rather than precision-critical bushings, improving both reliability and assembly ease.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The connection plates are pre-welded to the structural sections during manufacturing with generous tolerances. This preliminary action separates the welding operation from the alignment-critical screw insertion step, allowing welds to be performed without precision alignment requirements while maintaining joint reliability.

Inventive Principle:

Principle #10Preliminary action

2Strength

If precise alignment of screw bushings is required, then joint strength is improved, but assembly time increases and reliability decreases

Engineering Contradiction:

Improvejoint strengthVSAvoidassembly time

Core Design Contradiction:

StrengthVSLoss of time

Solution Approach 1:

Connection plates serve as intermediary elements between the structural sections and the screw bushings. These plates provide a robust welding surface that can be attached with relaxed tolerances, while the separate attachment pieces with precision-machined bushings can be easily aligned and removed after screw insertion, reducing assembly time.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The precision alignment requirement is extracted from the welding operation and transferred to a separate, easily adjustable attachment piece. The connection plates are welded without precision alignment, then the attachment pieces with precisely positioned bushings are temporarily attached, allowing screws to be inserted without time-consuming alignment of permanently fixed bushings.

Inventive Principle:

Principle #2Taking out (Extraction)

3Device complexity

If welds are used to fix screw bushings, then device complexity is reduced, but harmful factors increase due to risk of structural collapse

Engineering Contradiction:

Improvejoint system complexityVSAvoidstructural collapse risk

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The design incorporates redundant connection paths: both welded connection plates and mechanically attached attachment pieces with screw bushings. This provides a backup mechanism that cushions against the harmful effect of potential weld defects, preventing structural collapse even if welding fails.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

Connection plates act as intermediary elements that distribute loads and provide alternative load paths. If welds on the connection plates fail, the structural integrity is maintained through the mechanical attachment of the attachment pieces, cushioning against the harmful effect of weld failure.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP4335806B1Attachment joint for coupling between structural modules of tower cranes

Publication Date: 2025.12.31 LINDEN COMANSA

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AI summary

A structural section (2) of a tower crane consisting of latticework with vertical beams (10), crosspieces (11) and diagonals (12) with an attachment joint comprising a coupling (1) for coupling to a contiguous structural section (2'). Said coupling (1) comprises a flat base (3) fixed to a connection block (4) welded at the end of each vertical beam (10) of the structural section (2), the flat base (3) covering a perimeter of the projection of said connection block (4).At least two ends of the connection block (4) protruding with respect to the projection of the vertical beam (10). Each of said ends of the connection block (4) comprises a through hole for the introduction of a screw for attachment with a connection block (4') of the contiguous structural section (2'). The flat surface of the flat base (3) of a structural section (2) remains in the assembly position in direct contact with the flat base (3') of the adjacent structural section (2').