Drum Lid Clamping Ring for Pressure Stability

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Solution Overview

Problem

Existing lidded drums with a volume of 150 liters meet mechanical stability requirements for hazardous liquids under 1 bar internal pressure for 30 minutes, but larger drums, such as 220 liters, lack sufficient stability to withstand prolonged internal pressure without leaks or lid detachment.

Innovation Solution

The clamping ring rests on the upper edge of the barrel mouth, with a flat upper edge and inwardly directed collar, providing double locking and stabilizing the lid, while the clamping ring's U-shaped cross-section and L-shaped extension enhance peripheral stability, allowing controlled deformation under pressure without compromising the seal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of stationary object

If the drum volume is increased to 220 liters, then the capacity is improved, but the mechanical stability under internal pressure deteriorates

Engineering Contradiction:
Improvedrum volumeVSAvoidmechanical stability under pressure
Core Design Contradiction:
Volume of stationary objectVSReliability

Solution Approach 1:

The clamping ring is extended upward in the axial direction to contact the upper edge of the bead, creating a second contact zone. This dimensional extension transforms the single-plane clamping into a multi-plane constraint system, providing additional support against internal pressure in larger drums.

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

Solution Approach 2:

The clamping function is segmented into two distinct contact zones: the first at the outer flange level and the second at the upper bead edge. This segmentation allows each zone to handle specific stress components, with the upper contact zone specifically addressing the lid detachment risk in large-volume drums.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If the upper edge of the bead is curved, then the manufacturing is easier, but the lid stability under pressure deteriorates

Engineering Contradiction:
Improvebead shapingVSAvoidlid stability under pressure
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The bead is designed with differentiated local geometry: the main body retains a curved profile for manufacturing ease, while the upper edge features a localized flat segment. This local quality change creates a stable contact surface for the clamping ring without requiring complete redesign of the entire bead structure.

Inventive Principle:
Principle #3Local quality

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 enhanced design ensures the lid remains secure under 1.3 bar internal pressure for 30 minutes without leaks, meeting approval criteria for larger drums by distributing pressure and preventing upward movement of the lid.

Implementation Method 1

the clamping ring (additionally) rests on the upper edge of the bead, which surrounds or overlaps the edge of the barrel mouth

Methodology Applied
Scientific EffectMechanical Force: Force

Implementation Method 2

the clamping ring also has a circumferential, inwardly directed collar in the upper area and that the underside of the collar of the clamping ring is flat

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

The flat design of the upper edge of the bead and of the collar of the clamping ring stabilizes this arrangement, so that when the barrel is under overpressure it is no longer possible to bend up the collar

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 4

During the period of 30 minutes, the thermoplastic high-density polyethylene gradually deforms (creep behavior)

Methodology Applied
Scientific EffectCreep: Creep

Data Source

PatentEP1834891B1Drum with lid and corresponding circlip
Publication Date: 2008.12.24 MUHLHOFF HARTMUT
  • EP1834891B1 patent drawingFigure 1~2
  • EP1834891B1 patent drawingFigure 3~4
  • EP1834891B1 patent drawingFigure 5~7

AI summary

The lid has a clamping ring lying on the upper edge of the lid, which encompasses or overlaps the barrel aperture edge. A projection is designed at the lid and intervenes in a corresponding opening (6) in the clamping ring. Two opposite and elongated projections proceed in circumferential direction of the lid. The projections are provided on the cylinder barrel of the lid between the external flange and the upper edge of the lid, which intervene in the corresponding longitudinal slots of the clamping ring. An independent claim is also included for a clamping ring for a barrel lid.