Adjustable Connecting Rod With Constant Resistive Torque

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Solution Overview

Problem

Existing length-adjustable connecting rods face manufacturing and assembly complexities due to double threads, which complicate the adjustment process and result in varying tightening torque depending on the position of the fork relative to the tube, posing safety risks and inefficiencies.

Innovation Solution

A connecting rod design featuring a single thread per end with a resistant torque device comprising a pressing element and a support element, where the support element is integral with the junction element and the pressing element is integral with the connecting rod body, providing a constant resistant torque regardless of the fork's position, achieved through a manufacturing process that includes a single injection step and integral components like ball pushers or leaf springs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a double thread system is used with an intermediate sleeve to enable length adjustment, then the connecting rod can be adjusted in length, but the manufacturing and assembly complexity increases significantly

Engineering Contradiction:
Improvelength adjustabilityVSAvoidthread system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent removes the intermediate sleeve component from the thread system, extracting the problematic element that caused the double thread complexity. The connecting element now directly engages with the tube through a single thread, eliminating the need for the intermediate sleeve while preserving length adjustability through the same threading mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the functions of the intermediate sleeve and the connecting element into a single integrated component. The connecting element now directly incorporates the threading interface with the tube, combining what were previously separate functional elements into one unified part, thereby simplifying the overall assembly.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If additional locking mechanisms are added to secure the thread, then the locking reliability improves, but the manufacturing complexity and assembly steps increase

Engineering Contradiction:
Improvethread locking reliabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The friction between the connecting element and the tube naturally provides the locking function, eliminating the need for additional active locking mechanisms. The system uses its own operational characteristics (friction) to maintain the adjusted position, making the locking function self-generated rather than requiring separate components or steps.

Inventive Principle:
Principle #25Self-service

3Strength

If the resistant torque device uses offset fastening elements, then the structural design is achieved, but the tightening torque varies with fork position causing safety risks

Engineering Contradiction:
Improveresistant torqueVSAvoidtorque consistency
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent introduces asymmetry in the positioning of the resistant torque device components relative to the axis of rotation. By strategically placing the pressing element and support element at specific asymmetric positions, the device compensates for the varying fork position, maintaining consistent tightening torque throughout the rotation range.

Inventive Principle:
Principle #4Asymmetry

4Strength

If prominent fastening elements are used in the resistant torque device, then the structural connection is achieved, but the operator safety is compromised due to injury risks

Engineering Contradiction:
Improveconnection strengthVSAvoidoperator injury risk
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent embeds the fastening elements of the resistant torque device within the internal structure of the connecting rod components. The pressing element and support element are positioned inside the tube and connecting element respectively, with their interaction occurring internally, thereby eliminating prominent external features that could injure operators while maintaining the necessary connection strength.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 solution simplifies the manufacturing and assembly of length-adjustable connecting rods, ensuring a consistent resistant torque across all positions, enhancing safety and operational efficiency by eliminating the need for additional locking mechanisms and reducing the risk of operator injury.

Implementation Method 1

at least one pressing element exerting a force on at least one support element which opposes a resistance to the rotational movement of the connecting rod body relative to said connecting element

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4103855B1Length adjustable connecting rod with a restisting torque device
Publication Date: 2024.04.03 EPSILON COMPOSITE
  • EP4103855B1 patent drawingFigure 1~3
  • EP4103855B1 patent drawingFigure 4~6c
  • EP4103855B1 patent drawingFigure 7~9

AI summary

The invention relates to a length-adjustable connecting rod having a longitudinal axis (5), comprising a connecting-rod shank (50) provided with at least one internal thread (546), at least one bonding member (10, 20) comprising an external thread (106) cooperating with the internal thread of the connecting-rod shank, the screwing or unscrewing of the connecting-rod shank relative to the bonding member enabling the length of the connecting rod to be adjusted, and at least one resistive torque device between the connecting-rod shank and the bonding member, the resistive torque device comprising at least one pressing element (530, 730) and a bearing element (331), the pressing element exerting a force on the bearing element which opposes a resistance to the rotational movement of the connecting-rod shank relative to the bonding member. The bearing element (331) is rigidly connected to the bonding member (10, 20) and the pressing element (530, 730) is rigidly connected to the connecting-rod shank (50) and the force is exerted by the pressing element (530, 730) on the bearing element (331) in a transverse direction and perpendicular to the longitudinal axis (5) of the connecting rod. The invention also relates to the method for manufacturing and assembling the connecting rod.