Safety Clamp Cam Mechanism for Automatic Cable Break Retention

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current cable recovery systems in overhead power line reconductoring operations face frequent interruptions due to mid-span and by-pass joints, leading to potential cable breakage and loss of the pulling line, which can have catastrophic consequences, and existing safety clamps do not automatically retain the cable during breakage or require complex installation.

Innovation Solution

A safety clamp with jaws and a cam mechanism that automatically activates to clamp the cable upon breakage, using a driving device connected to a damper for tensioning and ensuring the cable remains anchored to the machine, preventing further motion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a safety clamp is installed to prevent cable breakage, then cable safety is improved, but device complexity increases

Engineering Contradiction:
Improvecable safetyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The safety clamp is designed with automatic activation through a cam mechanism that engages when cable motion reverses during breakage. The system self-activates without external control signals, using the cam profile to automatically trigger jaw closure when the cable pulls in the wrong direction, eliminating the need for sensors or complex control systems

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The safety function is extracted as a separate, dedicated clamp device with specialized automatic activation mechanism. Rather than integrating safety features into the existing winch-brake system, a distinct safety clamp with its own cam-based trigger mechanism is installed, allowing independent optimization of safety functionality without complicating the main cable laying system

Inventive Principle:
Principle #2Taking out (Extraction)

2Loss of time

If manual monitoring and intervention is used to detect cable breakage, then response time is improved, but labor requirements increase

Engineering Contradiction:
Improveresponse timeVSAvoidlabor requirements
Core Design Contradiction:
Loss of timeVSEase of operation

Solution Approach 1:

The safety clamp automatically detects cable breakage through the cam mechanism that senses reverse motion of the cable. Upon detection, the system self-activates to clamp the cable without requiring manual intervention, providing instantaneous response to breakage events while eliminating the need for operators to continuously monitor cable status

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The cam mechanism provides mechanical feedback by detecting the direction of cable motion. When cable motion reverses (indicating breakage), the cam profile automatically triggers the clamping action, creating a closed-loop safety system that responds immediately to abnormal conditions without human intervention

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If complex safety clamp installation is required, then installation precision is improved, but installation time increases

Engineering Contradiction:
Improveinstallation precisionVSAvoidinstallation time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The safety clamp is designed as a modular assembly with distinct components (jaws, cam mechanism, wheels, spring element) that can be pre-assembled and tested separately. This segmentation allows for standardized installation procedures and reduces on-site assembly complexity, enabling quick installation while maintaining precise mechanical relationships between components

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cam mechanism and jaw alignment are pre-configured during manufacturing with precise geometric relationships established beforehand. The cam profile is pre-formed to ensure correct engagement geometry, eliminating the need for complex field adjustments and ensuring proper installation precision through factory-prepared configurations

Inventive Principle:
Principle #10Preliminary action

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

The safety clamp effectively prevents cable drop and damage by automatically clamping the cable upon breakage, ensuring continuous operation and adherence to safety standards without complex installation requirements.

Implementation Method 1

a cam and a plurality of wheels opposing the cam... when the cable slides in a second direction opposite the first direction, for example following a breakage, the cam automatically activates

Methodology Applied
Scientific EffectCam mechanism: Cam

Implementation Method 2

The cam can rotate around a corresponding pin attached to the support... The cam comprises an elastic element, for example a torsion spring, that tends to keep it in an inactive position

Methodology Applied
Scientific EffectSpring energy storage: Spring

Implementation Method 3

The cable is, during use, positioned and sliding between the cam and the plurality of wheels... pressing the cable against at least one of the wheels

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4683139A1Safety clamp for cable stringing operations
Publication Date: 2026.01.21 TESMEC
  • EP4683139A1 patent drawingFigure 1a~1b'
  • EP4683139A1 patent drawingFigure 2
  • EP4683139A1 patent drawingFigure 3~5

AI summary

Safety clamp (10) for cable stringing operations, comprising a pair of jaws (11, 12) opened or closed by means of a driving device (13), configured to be connected, during use, to an attachment element (14) associated with a machine (15) for recovering a cable (16) sliding on a cam (17) and along a plurality of wheels (18, 19) opposing the cam (17); when the cable (16) slides toward the machine (15) in a first direction (D1), the jaws (11, 12) are in a first open position of passage of the cable (16) and the cam (17) is inactive, while, when the cable (16) slides in a second direction (D2) opposite the first direction (D1), the cam (17) automatically activates, pressing the cable (16) against at least one of the wheels (18, 19) and associating it with the safety clamp (10), and the driving device (13), since it is connected to the attachment element (14), puts the safety clamp (10) under tension and determines the passage of the jaws (11, 12) from the first open position to a second position of clamping the cable (16), which entails interrupting the motion of the cable (16) and of the safety clamp (10) associated therewith in the second direction (D2).