Bayonet-Locked Inversion Unit Window for Faster Pipe Relining Access

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Solution Overview

Problem

Existing inversion units for pipe-relining have limited window size and require time-consuming screwing movements for opening and closing, hindering efficient access and operation.

Innovation Solution

The design incorporates a bayonet mechanism with a handle for smooth and efficient opening and closing of a larger window, utilizing a motion link assembly and matching projection assembly for secure locking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a screw-based window locking mechanism is used, then the window can be securely closed, but the opening and closing process becomes time-consuming

Engineering Contradiction:
Improvewindow locking reliabilityVSAvoidtime for opening and closing window
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the traditional screw-based mechanical locking system with a bayonet-style quarter-turn locking mechanism. This substitution maintains secure locking reliability while dramatically reducing the time required to open and close the window, as the bayonet mechanism requires only a quarter rotation rather than multiple screwing motions.

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

Solution Approach 2:

The patent introduces a motion link assembly that dynamically translates the rotational motion of the handle into the linear motion required for locking engagement. This dynamic mechanism allows the window to be quickly secured through a simple rotational action, improving both speed and ease of operation while maintaining reliability.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If a larger window is provided for better access, then manual work capability is improved, but the locking mechanism complexity increases

Engineering Contradiction:
Improveaccess to drum interiorVSAvoidwindow locking mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent divides the locking mechanism into distinct functional modules: a handle for user interaction, a motion link assembly for motion translation, and a projection assembly for locking engagement. This segmentation allows each component to be optimized independently, managing complexity while enabling a larger window design for improved access.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bayonet locking mechanism serves multiple functions: it provides secure locking, enables quick release, and maintains structural integrity of the larger window opening. The motion link assembly simultaneously guides the locking motion and provides mechanical advantage, reducing the effort needed to operate the larger window.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution enhances handling and operation by providing easy access through a larger window with a reliable locking mechanism, improving the overall efficiency of the pipe-relining process.

Implementation Method 1

The window locking mechanism is designed as a bayonet catch and comprises a motion link assembly and a matching projection assembly. The window locking mechanism further comprises a handle and a hinge, the handle being pivotably connected to the hinge wherein one of the motion link assembly or the matching projection assembly is arranged on the window and the other of the matching projection assembly or the motion link assembly is arranged on an edge of the opening.

Methodology Applied
Scientific EffectBayonet mechanism:

Implementation Method 2

The hinge is arranged on the housing and the handle is pivotably connected to the window so that the window can be easily opened and closed in a bayonet catch manner using the handle.

Methodology Applied
Scientific EffectHinge mechanism: Hinge

Data Source

PatentEP4403506B1Inversion unit with window
Publication Date: 2025.05.07 SACPRO AB
  • EP4403506B1 patent drawingFigure 1~3b
  • EP4403506B1 patent drawingFigure 4a~5b
  • EP4403506B1 patent drawingFigure 6

AI summary

Disclosed herein is an inversion unit comprising a housing (2), a reel (4) for a liner partially arranged in the housing (2), and a base assembly (6), the housing (2) being arranged on the base assembly (6), said housing (2) comprising a gas inlet (36), an outlet (8) for the liner, an opening (10) comprising a window (14) and a window locking mechanism (12) for closing and opening the window (14). The window locking mechanism (12) is designed to be manoeuvred into an open position in which the window (14) is open and unlocked and a closed position in which the window (14) is closed and locked. The window locking mechanism (12) is designed as a bayonet catch and comprises a motion link assembly (16) and a matching projection assembly (18), the window locking mechanism (12) further comprising a handle (20) and a hinge (28), the handle (20) being pivotably connected to the hinge (28) wherein one of the motion link assembly (16) or the matching projection assembly (18) is arranged on the window (14) and the other of the matching projection assembly (18) or the motion link assembly (16) is arranged on an edge of the opening (10), wherein the hinge (28) is arranged on the housing (2) and wherein the handle (20) is pivotably connected to the window (14) so that the window (14) can be easily opened and closed in a bayonet catch manner using the handle (20).