Compact Locking Head for Telescopic Crane Booms

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Solution Overview

Problem

The existing locking heads for telescoping cylinders in crane booms are bulky, heavy, and require complex manufacturing due to axial offsets and decentralized drive mechanisms, leading to increased length, weight, and manufacturing costs.

Innovation Solution

A compact locking head design with a housing and transversely guided locking claw, utilizing centrally arranged unlocking pistons and a rack-and-pinion drive, which reduces the overall length and weight while minimizing friction and manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the hydraulic means for actuating the locking claw is offset axially to a different plane than the cylinder locking bars, then the locking mechanisms can be arranged separately, but the locking head length and volume increase significantly

Engineering Contradiction:
Improvearrangement of locking mechanismsVSAvoidlocking head length
Core Design Contradiction:
Device complexityVSLength of moving object

Solution Approach 1:

The patent merges the hydraulic actuation plane with the cylinder locking bars plane, eliminating the axial offset between these components. This consolidation reduces the locking head length while maintaining functional separation through spatial arrangement within the same plane.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Instead of separating components along the axial dimension (creating offset planes), the invention rearranges them within the radial and transverse dimensions, keeping everything in the same axial plane. This dimensional reorganization reduces length without compromising mechanism independence.

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

2Device complexity

If the translational drive for the locking claw is placed outside the plane of movement of the cylinder bars, then the locking mechanisms are spatially separated, but a bending moment is introduced into the locking claw

Engineering Contradiction:
Improvespatial separation of mechanismsVSAvoidlocking claw stress
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The invention positions the translational drive for the locking claw within the same plane as the cylinder bars movement, creating a balanced configuration. This eliminates the bending moment by ensuring forces are applied collinearly, while spatial separation is achieved through radial positioning rather than axial offset.

Inventive Principle:
Principle #12Equipotentiality

3Power

If the diameter of the piston rod increases, then the telescoping cylinder capacity increases, but the distance between actuating pistons for the locking claw must increase, requiring custom manufacturing

Engineering Contradiction:
Improvetelescoping cylinder capacityVSAvoidlocking claw manufacturing
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The patent designs the locking claw with a universal configuration where the actuating pistons are positioned relative to the locking claw's center of gravity rather than depending on piston rod diameter. This allows the same locking claw design to be used across different cylinder sizes, eliminating custom manufacturing requirements while maintaining power scalability.

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

Solution Approach 2:

Instead of changing the locking claw geometry with piston rod diameter, the invention changes the positioning parameters of the actuating pistons relative to a fixed locking爪 design. This parameter adjustment approach maintains manufacturing simplicity while adapting to different power requirements.

Inventive Principle:
Principle #35Parameter changes

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 results in a 50% weight savings and reduced installation dimensions, enabling a shorter telescoping cylinder and boom length, along with simplified manufacturing and reduced maintenance costs due to minimized sealing needs and friction losses.

Implementation Method 1

The locking claw (5) has a central collar (11) on which unlocking pistons (12, 13) act

Methodology Applied
Scientific EffectHydraulic force: Hydraulic Press

Implementation Method 2

The locking claw (5) can be returned into the locked position by return springs (14)

Methodology Applied
Scientific EffectElastic force: Spring

Implementation Method 3

The locking claw (5) is guided in the housing (2) via a guide (10) arranged on the peripheral side of the locking claw (5)

Methodology Applied
Scientific EffectMechanical guidance: Guided Rotor Compressor

Data Source

PatentEP2218672B1Locking head
Publication Date: 2013.05.01 MONTANHYDRAULIK
  • EP2218672B1 patent drawingFigure 1
  • EP2218672B1 patent drawingFigure 2
  • EP2218672B1 patent drawingFigure 3~4

AI summary

The head (1) has crane arm including a housing (2) with cylindrical bars (3, 4) for locking the head with telescopic sections, where the cylindrical bars translatively move in the housing. A bar pawl (5) actuates an unlocking device of the telescopic sections, and moves opposite to the housing. The bar pawl moves perpendicular to the cylindrical bars and a telescopic cylinder, and is guided to the housing by a guide (10) that is arranged on a peripheral side of the bar pawl. The guide is arranged in an identical transverse plane that runs perpendicular to the telescopic cylinder.