Swinging Suspender with Spherical Braking Surfaces

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Solution Overview

Problem

Existing swinging suspenders with double action brakes for cranes are either complex, space-intensive, or fail to provide sufficient braking force, making them difficult to manufacture robustly enough to handle high loading forces.

Innovation Solution

The design features a body portion with concave and convex braking surfaces on the piston and cylinder, respectively, with pivot axes oriented perpendicularly to allow two-axis swinging, and a floating cylinder placement to enhance braking efficiency, along with sealing rings to maintain oil pressure and a spring mechanism for controlled braking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the piston shafts collide directly onto the pivot axis with small braking surfaces, then the construction is simple, but the braking force is moderate and insufficient for high loading forces

Engineering Contradiction:
Improvebraking forceVSAvoidbrake construction complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent applies spherical braking surfaces with a radius of curvature R that is at least three times the radius of the pivot pin. The concave spherical surface is formed on the piston shaft end and the convex spherical surface on the connecting piece, creating a point contact that concentrates the braking force and allows sufficient braking capability with a simple construction.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent changes the geometric parameters of the braking surfaces by using spherical geometry instead of flat or ring-shaped surfaces. The specific parameter is the radius of curvature R, which is designed to be at least three times the pivot pin radius, optimizing the contact geometry for high force transmission while maintaining construction simplicity.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If ring shaped braking surfaces are used as in US 2011081193 A1, then the braking surface area is increased, but the construction becomes complicated, space requiring and difficult to make robust

Engineering Contradiction:
Improverobustness and simplicity of constructionVSAvoidbraking surface area
Core Design Contradiction:
Ease of manufactureVSArea of stationary object

Solution Approach 1:

Instead of using extended ring-shaped braking surfaces that complicate the construction, the patent employs spherical braking surfaces that concentrate the braking action at a point contact. This spherical geometry provides sufficient braking capability while maintaining a simple, compact, and robust construction that is easier to manufacture.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent inverts the conventional approach of using large-area ring-shaped braking surfaces by using small-area spherical surfaces. This inversion achieves the opposite effect: instead of spreading the braking force over a large area, it concentrates the force at a point, which simplifies the construction while maintaining robustness for high loading forces.

Inventive Principle:
Principle #13The other way round (Inversion)

3Reliability

If the cylinder is fixed to the body portion, then the construction is stable, but the braking efficiency is reduced due to restricted movement

Engineering Contradiction:
Improvebraking efficiencyVSAvoidcylinder mounting complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the cylinder dynamic by allowing it to float or move freely within the body portion during braking operations. The cylinder is not rigidly fixed but can shift position to optimize the braking action, improving braking efficiency while the guide elements ensure controlled movement and prevent excessive displacement.

Inventive Principle:
Principle #15Dynamics

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

This configuration simplifies the construction, enhances robustness, and provides a high braking force, effectively controlling uncontrolled swinging of tools like loading grabbers, thereby preventing accidents and facilitating safer operations.

Implementation Method 1

A hydraulic, pneumatic or electric cylinder (6) is positioned between the pivot pins or bolts (3, 11)

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

A hydraulic, pneumatic or electric cylinder (6) is positioned between the pivot pins or bolts (3, 11)

Methodology Applied
Scientific EffectPneumatic pressure: Gas Compressor

Implementation Method 3

The connecting piece (4) and the jointing lug (14) are provided with convex braking surfaces (5, 10) which are adapted to be pressed into a braking contact with the concave braking surfaces (7, 8) when the piston (6b) is extended from the cylinder (6)

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 4

a spring mechanism for controlled braking

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3578499B1Swinging suspender with double action brake
Publication Date: 2021.04.07 NOKKA JOINDE OY
  • EP3578499B1 patent drawingFigure 1
  • EP3578499B1 patent drawingFigure 2
  • EP3578499B1 patent drawingFigure 3

AI summary

The invention concerns a swinging suspender with double action brake for suspending a working tool from a crane jib (15). The suspender comprises a body portion (1, 16) having connecting lugs (2, 22) at its opposite ends. A connecting piece (4) is connected to the first connecting lugs (2) with a first pivot pin or bolt (3) which constitutes a first pivot axis which enables swinging of the working tool. A jointing lug (14) of the working tool is connected to the second connecting lugs (22) with a second pivot pin or bolt (11) which constitutes a second pivot axis which enables swinging of the working tool, said first and second pivot axis having their directions perpendicular to each other, thereby enabling swinging of the working tool in two perpendicular directions. For the double action brake there is a hydraulic, pneumatic or electric cylinder (6, 16) between the pivot pins or bolts (3, 11), and one or two pistons (6a, 6b) in the cylinder (6, 16). The opposite ends of the piston (6b) and cylinder (6) or the opposite ends of the two pistons (6a, 6b) are shaped as concave braking surfaces (7, 8). The connecting piece (4) and the jointing lug (14) are provided with convex braking surfaces (5, 10) which are adapted to be pressed into a braking contact with the concave braking surfaces (7, 8) when the piston (6b) or pistons (6a, 6b) are extended from the cylinder (6, 16). The cylinder (6, 16) has a center line which passes through the concave and convex braking surfaces (7, 8; 5, 10) which are in the form of partial circles.