Two-Stage Lock Assembly for Folding Table Leg Collapse Prevention

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Solution Overview

Problem

Conventional banquet tables are bulky, heavy, and costly due to wooden or metal tabletops, requiring large storage spaces and additional reinforcing members, which increase manufacturing time and cost, and may pose safety hazards with sharp edges. The leg assemblies often collapse or detach under load, and the locking mechanisms are unreliable.

Innovation Solution

A table with a blow-molded plastic tabletop and a two-stage lock assembly that includes a multi-element lock tab to prevent collapse, featuring a support element that rotates between storage and use positions, and a translation mechanism that translates along the support element, ensuring secure locking in the use position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional wooden or metal tabletops are used, then the table has sufficient strength and durability, but the table becomes heavy and expensive with large storage requirements

Engineering Contradiction:
Improvetabletop strengthVSAvoidtable weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent changes the material parameter from traditional wood or metal to plastic, achieving a balance between strength and weight. The plastic tabletop provides sufficient structural integrity while being significantly lighter and more cost-effective than conventional materials.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite construction by integrating reinforcing members within the plastic tabletop structure. This composite approach enhances the strength of the plastic material while maintaining its weight advantage, resolving the contradiction between strength and weight.

Inventive Principle:
Principle #40Composite materials

2Weight of moving object

If lightweight materials like plastic are used for the tabletop, then the table weight decreases, but the tabletop requires large reinforcing members and additional structural parts that increase weight and complexity

Engineering Contradiction:
Improvetabletop weightVSAvoidtabletop structure complexity
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The patent merges the tabletop surface and reinforcing members into a single integrated plastic structure. The reinforcing members are embedded within the tabletop during molding, eliminating the need for separate attachment processes and reducing overall structural complexity despite the addition of reinforcement elements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The plastic tabletop serves multiple functions simultaneously: it provides the surface for use, acts as a structural frame, and incorporates reinforcing members for strength. This multi-functionality reduces the need for additional separate components, thereby reducing complexity.

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

3Ease of manufacture

If simple locking mechanisms are used, then the manufacturing cost and time are reduced, but the leg assemblies may collapse or detach under load

Engineering Contradiction:
Improvelocking mechanism manufacturingVSAvoidleg assembly stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The locking mechanism is pre-configured within the leg assembly structure during manufacturing. The lock tabs and receivers are integrated into the design, so that when the leg assembly is extended to its full length, the locking action occurs automatically without requiring additional assembly steps or complex mechanisms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The leg assembly's locking mechanism is designed to be self-activating. When the leg assembly reaches its extended position, the geometry of the components causes the lock tabs to engage with the receivers automatically, providing reliable locking without external intervention or complex control systems.

Inventive Principle:
Principle #25Self-service

4Volume of stationary object

If the table is designed for easy storage with folded legs, then the storage space requirement decreases, but the locking mechanism may be insufficient and cause collapse

Engineering Contradiction:
Improvestorage spaceVSAvoidlock assembly reliability
Core Design Contradiction:
Volume of stationary objectVSReliability

Solution Approach 1:

The leg assembly is segmented into movable and fixed portions that can be folded against the tabletop for storage. The two-stage lock assembly is positioned to engage at specific intervals during the folding and extending process, providing reliable locking in both the extended use position and the folded storage position.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The two-stage locking mechanism provides preliminary security during the transition from folded to extended position. The first lock engages early in the extension process to prevent accidental collapse, and the second lock engages at the final extended position to provide secure locking for full load-bearing capacity.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP3996548B1Table comprising a two-stage lock assembly
Publication Date: 2025.08.27 LIFETIME PRODUCTS
  • EP3996548B1 patent drawingFigure 1A
  • EP3996548B1 patent drawingFigure 1B
  • EP3996548B1 patent drawingFigure 1C

AI summary

A two-stage lock assembly comprising a multi-element lock tab configured for disposition in a lateral structure of a lock device. The multi-element lock tab may include a body that includes an end on which a first element and a second element are disposed. The first element may extend from the body farther than the second element to enable the first element to be introduced into a receiver prior to the second element. The multi- element lock tab may be configurable in a disengaged configuration in which the first element and the second element are not positioned in a receiver, a first engaged configuration in which the first element is positioned in the receiver and the second element is not, and a second engaged configuration in which the first and the second elements are positioned in the receiver.