Telescopic Cylinder Locking Layout for Compact Yoke Guidance

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Solution Overview

Problem

Existing locking devices for telescopic booms require large installation space due to the arrangement of guide elements outside the central plane, leading to potential jamming and interference with actuation mechanisms.

Innovation Solution

A locking device with a yoke and bolt configuration where the bolt return elements are arranged laterally, allowing a blocking element to occupy the space previously needed for central springs, enabling compact design and dual function of guiding the yoke while preventing simultaneous unlocking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If guide elements are arranged outside the central plane, then the yoke can be guided within the housing, but the installation space increases and jamming may occur

Engineering Contradiction:
Improveyoke guidance reliabilityVSAvoidinstallation space
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The guide elements are relocated from a three-dimensional arrangement outside the central plane to a two-dimensional arrangement within the central plane, effectively using the planar space more efficiently. This dimensional reorganization allows the guide elements to coexist with the actuation mechanisms without increasing the overall installation footprint.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The guide elements and the actuation mechanisms are merged into the same central plane, allowing them to share the available space without interference. This consolidation eliminates the need for separate spatial zones and reduces the overall installation space requirement while maintaining functional independence.

Inventive Principle:
Principle #5Merging (Combining)

2Area of stationary object

If guide elements are relocated within the central plane, then installation space is reduced, but spatial conflict arises with actuation and return mechanisms

Engineering Contradiction:
Improveinstallation spaceVSAvoidspatial arrangement complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The central plane is segmented into distinct functional zones: one area for guide elements and another for actuation/return mechanisms. This segmentation allows both sets of components to coexist within the same plane without spatial conflict, maintaining clear functional separation while optimizing space utilization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Components are arranged in different layers or levels within the central plane, effectively using the planar space in a multi-layered configuration. This approach allows guide elements and actuation mechanisms to occupy the same two-dimensional space without physical interference, reducing overall device complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Force

If return springs are arranged outside the central plane, then bolt pre-tensioning is achieved, but installation space increases

Engineering Contradiction:
Improvebolt pre-tensioning forceVSAvoidinstallation space
Core Design Contradiction:
ForceVSArea of stationary object

Solution Approach 1:

The return springs are merged with the guide elements and positioned within the central plane, allowing them to share the same spatial zone. This integration eliminates the need for separate external spring housing and reduces the overall installation space while maintaining the necessary bolt pre-tensioning force.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The guide elements serve dual functions: guiding the yoke movement and housing the return springs for bolt pre-tensioning. This multi-functionality reduces the number of separate components and their associated space requirements, achieving both guidance and force application within the same structural element.

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

The solution achieves a compact and efficient locking mechanism with improved guidance and smooth operation, reducing the likelihood of jamming and requiring less installation space.

Implementation Method 1

The at least one bolt is pre-tensioned into a locking position by at least one bolt return element

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 2

at least one blocking element which blocks movement of the bolt into its unlocking position when the yoke is in the unlocking position

Methodology Applied
Scientific EffectMechanical blocking: Mechanical Force

Implementation Method 3

the yoke is slidably mounted and guided within a housing of the locking device by means of several guide elements

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4479337B1Locking device for telescopic cylinder
Publication Date: 2025.11.12 LIEBHERR COMPONENTS KIRCHDORF GMBH
  • EP4479337B1 patent drawingFigure 1
  • EP4479337B1 patent drawingFigure 2a
  • EP4479337B1 patent drawingFigure 2b~3

AI summary

Locking device (10) for the telescopic cylinder of a telescopic boom comprising a plurality of telescopic stages. The locking device comprises a housing (12), at least one bolt (20) displaceably mounted in the housing for locking the telescopic cylinder with a telescopic stage, a yoke (30) displaceably mounted in the housing, which is movable into an unlocking position for releasing a locking bolt of the telescopic boom, and at least one blocking element (35), which blocks a movement of the bolt into its unlocking position when the yoke is in the unlocking position. The at least one bolt is preloaded into a locking position via at least one bolt return element (22) and can be displaced via at least one bolt actuator (24) into an unlocking position releasing the telescopic stage lock. The blocking element and the bolt can be at least partially displaced into a common insertion space of the housing. According to the invention, the bolt is preloaded into the locking position via at least two bolt return elements, wherein the blocking element is arranged between the bolt return elements as seen in the displacement direction of the yoke. The invention further relates to an implement, in particular a mobile crane, having a locking device according to the invention.