Overhead Contact Line Busbar Joint Alignment and Sag Compensation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for connecting conductor rails in catenary systems face issues with sagging and kinking due to deflection at joints, despite the use of screw connections and additional positive tongue and groove connections, which cannot fully prevent deformations.

Innovation Solution

The method involves raising conductor rails between support points by the calculated or measured amount of sag before connecting them with connecting pieces, ensuring exact alignment and using blind rivet bolts for a secure, form-fitting connection that prevents kinking and maintains the rails on a single axis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If busbars are connected with screw connections and positive tongue and groove connections, then connection strength is improved, but deformation and kinking at joints still occur due to hole play and deflection

Engineering Contradiction:
Improveconnection strengthVSAvoidalignment precision at joints
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent applies preliminary anti-action by pre-lifting the busbar at the joint location to compensate for expected sag before connection. This pre-positioning counteracts the gravitational sag that would otherwise cause misalignment and kinking at the joint, ensuring the busbar ends meet precisely at the correct height and angle during connection.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent implements preliminary action by performing the lifting operation before the actual connection process. The busbar is lifted to the predetermined height and position prior to inserting and securing the connecting piece, establishing the correct geometry in advance to prevent subsequent deformation.

Inventive Principle:
Principle #10Preliminary action

2Stability of the object's composition

If busbars are made with higher moment of inertia to reduce sag, then sag is reduced, but weight increases

Engineering Contradiction:
Improvesag reductionVSAvoidbusbar weight
Core Design Contradiction:
Stability of the object's compositionVSWeight of stationary object

Solution Approach 1:

The patent applies parameter changes by modifying the vertical position parameter of the busbar at the joint location through controlled lifting. Instead of changing the busbar's structural parameters (moment of inertia, cross-section) to reduce sag, the invention changes the installation parameter (height at joint) to compensate for sag, thereby avoiding weight increase.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If busbars are connected without pre-lifting, then installation is simpler, but kinks and deformations occur at joints due to sag

Engineering Contradiction:
Improveinstallation simplicityVSAvoidjoint alignment
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent introduces an intermediary element - the lifting mechanism and predetermined offset value - that mediates between the simple connection process and the requirement for precise alignment. The lifting operation acts as an intermediate step that prepares the busbar in the correct position before connection, bridging the gap between simplicity and precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2612789B1Method for connecting busbars
Publication Date: 2017.02.22 RAIL POWER SYST GMBH
  • EP2612789B1 patent drawingFigure 1~2
  • EP2612789B1 patent drawingFigure 3~6

AI summary

The invention relates to a method for connecting end-to-end conductor rails of an overhead contact line system. The method according to the invention is based on arranging the conductor rails to be connected at a predetermined height on predetermined support points and raising them by a predetermined amount at a predetermined point between the support points before the conductor rails abutting at the joints are firmly connected to each other using connecting pieces inserted into recesses in the conductor rails. After raising the conductor rails, the appropriate connecting pieces are firmly connected to the conductor rails. This ensures that the end pieces of the end-to-end conductor rails are precisely aligned with each other without being deflected, so that the connected conductor rails lie exactly on one axis.