Rebar Support Chair With Adjustable Legs for Single-Mold Production

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The traditional manufacturing of bar supports for rebars requires separate molds for each size and height, leading to substantial capital investments and recurring costs due to limited mold life and frequent mold changes, especially when multiple styles and heights are needed.

Innovation Solution

A rebar support chair design with conjoined legs and adjustable leg lengths using a single mold, allowing for the production of multiple heights and sizes without the need for multiple injection molds, and incorporating friction-enhancing features for stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate molds are used for each size and height of bar support, then manufacturing precision and product variety are improved, but capital investment and manufacturing cost increase substantially

Engineering Contradiction:
Improveproduct varietyVSAvoidmold quantity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies universality by designing a single injection mold that can produce multiple styles and heights of bar supports through adjustable leg assemblies. The mold includes a seat portion and a leg assembly with adjustable legs that can be configured in different positions and orientations. This allows one mold to replace multiple specialized molds, enabling production of various bar support configurations (different heights, styles, and orientations) while reducing the total number of molds required from potentially dozens to just one versatile mold system.

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

Solution Approach 2:

The patent applies dynamics through the adjustable leg assembly mechanism within the mold. The legs can be positioned at different locations, oriented at different angles, and extended to different lengths by adjusting the leg assemblies during the molding process. This dynamic adjustability allows the same mold cavity to produce bar supports with varying dimensions and configurations, transforming a static mold into a dynamically reconfigurable manufacturing tool that adapts to different product requirements without requiring physical mold changes.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If multiple injection molds are maintained for different bar support styles, then manufacturing precision is improved, but manufacturing downtime and labor costs increase due to frequent mold changes

Engineering Contradiction:
Improveproduct qualityVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The single versatile mold maintains manufacturing precision by incorporating precise positioning mechanisms and adjustable leg assemblies that can be configured to match the exact specifications required for different bar support styles. The mold includes features such as adjustable legs with controlled positioning, precise cavity configurations, and quality control mechanisms that ensure each produced bar support meets the required dimensional accuracy and structural integrity standards, regardless of the specific style being produced.

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

Solution Approach 2:

The dynamic adjustability of the leg assemblies enables rapid reconfiguration between different product specifications without requiring mold changes. The legs can be repositioned, reoriented, and reextended through adjustable mechanisms that maintain precision while allowing quick adaptation to different production requirements. This eliminates the downtime associated with physical mold changes while preserving manufacturing precision through controlled, repeatable positioning of the leg assemblies.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If a single mold is used to produce various bar support sizes and heights, then capital investment is reduced, but manufacturing precision and product consistency may worsen

Engineering Contradiction:
Improvemold quantityVSAvoiddimensional accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by providing different configurations of the leg assemblies within the same mold. Each leg assembly can be independently adjusted to specific positions, orientations, and extensions tailored to the required bar support specifications. The mold includes localized adjustment mechanisms for each leg, allowing precise control over the dimensions and geometry of each bar support produced. This ensures that each local configuration maintains the dimensional accuracy and geometric precision required for its specific application, even though the overall mold produces multiple different product variants.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The dynamic adjustment capabilities of the leg assemblies enable precise control over the dimensions and geometry of each bar support produced. The legs can be positioned with controlled accuracy at specific locations, oriented at precise angles, and extended to exact lengths through the adjustable mechanisms. This dynamic precision control ensures that each bar support, regardless of its specific configuration, meets the required dimensional tolerances and geometric specifications, maintaining manufacturing precision across all product variants produced by the single mold.

Inventive Principle:
Principle #15Dynamics

4Ease of manufacture

If traditional injection molding with fixed molds is used, then manufacturing process simplicity is maintained, but adaptability to different product specifications worsens

Engineering Contradiction:
Improveprocess simplicityVSAvoidproduct variety
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by transforming the traditionally static injection mold into a dynamically reconfigurable system. The leg assemblies incorporate adjustable mechanisms that allow the legs to be positioned at different locations, oriented at different angles, and extended to different lengths. This dynamic capability enables the same basic injection molding process to produce multiple different bar support configurations, maintaining process simplicity while dramatically increasing product variety and adaptability to different specifications.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies universality by designing the injection mold to perform multiple functions that traditionally required separate specialized molds. The single mold can produce bar supports of various heights, styles, and orientations through the adjustable leg assemblies, making the manufacturing process universally applicable to multiple product types. This maintains the simplicity of the injection molding process itself while expanding its versatility to handle diverse product requirements without complicating the fundamental manufacturing methodology.

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

Reduces capital expenditures and manufacturing costs by enabling the production of various bar support sizes and heights with a single mold, while enhancing stability through friction features, thus minimizing downtime and labor costs.

Implementation Method 1

injecting melted raw plastic into the mold

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

The mold includes a mold cavity, the mold cavity includes a receiving area portion and a plurality of leg portions

Methodology Applied
Scientific EffectCooling and solidification: Freezing

Data Source

PatentEP3892790B1Bar support and method of making a bar support
Publication Date: 2025.09.17 SORKIN FELIX L
  • EP3892790B1 patent drawingFigure 1~2
  • EP3892790B1 patent drawingFigure 3~4
  • EP3892790B1 patent drawingFigure 5~6

AI summary

A rebar support chair having a chair body including a plurality of conjoined legs, the conjoined legs defining a receiving area and a foot affixed to at least one leg.