Construction Material Mixer Snap-In Blade Replacement

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Solution Overview

Problem

The existing building material mixers, such as asphalt or concrete mixers, require significant time and effort to replace worn blades due to numerous structural screw connections, and often require specialized tools or measures like cutting torches or grinders when the parts are stuck or welded together.

Innovation Solution

The mixer design incorporates a snap-in and/or snap-in connection between the inner and outer parts of the mixing arm, allowing for tool-free blade replacement, with a latching connection device featuring pins and spring tabs, and adjustable spacers for blade positioning, enabling quick assembly and adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional screw connections are used to connect inner and outer parts of mixing arms, then structural strength is ensured, but blade replacement time and effort increase significantly

Engineering Contradiction:
Improveblade replacement timeVSAvoidconnection device complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The mixing arm is divided into inner and outer parts that can be quickly connected and disconnected. The connection device is segmented into pins with latching openings and molded parts with spring tabs, allowing rapid assembly and disassembly without tools, thus reducing blade replacement time while maintaining structural integrity through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connection device incorporates dynamic elements including spring tabs that can deflect during assembly and disassembly, and latching openings that engage/disengage based on the assembly state. This dynamic behavior enables quick tool-free operation while ensuring secure structural connection when assembled

Inventive Principle:
Principle #15Dynamics

2Ease of repair

If worn blades are replaced using traditional bolted connections, then reliable structural connection is achieved, but additional measures like cutting torches or grinders are required when parts are stuck

Engineering Contradiction:
Improveblade replacement easeVSAvoidadhering mix causing stuck parts
Core Design Contradiction:
Ease of repairVSObject-affected harmful factors

Solution Approach 1:

The connection device extracts the essential function of structural connection while eliminating the problematic bolted joints that can become stuck. By using pins with latching openings and spring tabs instead of threaded fasteners, the design removes the complexity of bolt tightening and prevents material adhesion issues associated with traditional screw connections

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The connection device uses simple, easily replaceable components including pins and molded parts with spring tabs. These components are designed for quick replacement without specialized tools, and if damaged or stuck, can be easily removed and replaced without requiring cutting torches or grinders, reducing repair complexity and time

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Stability of the object's composition

If multiple structural screw connections are used in mixing arms, then structural stability is maintained, but the number of connections that must be actuated increases blade replacement time

Engineering Contradiction:
Improvemixing arm structural stabilityVSAvoidblade replacement time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

Multiple connection functions are merged into a single integrated connection device comprising pins with latching openings and molded parts with spring tabs. This unified design maintains structural stability through the coordinated action of multiple latching points while requiring only a single assembly/disassembly motion, eliminating the need to actuate multiple independent screw connections sequentially

Inventive Principle:
Principle #5Merging (Combining)

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 design significantly reduces the time and effort required for blade replacement, allowing for easy on-site installation of new blades without tools, and allows for adjustable blade positioning for optimal performance.

Implementation Method 1

two spring tabs (25, 26) which can be introduced into the latching depressions (20, 21)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3675992B1Construction material mixer
Publication Date: 2021.05.12 AMMANN SCHWEIZ AG
  • EP3675992B1 patent drawingFigure 1
  • EP3675992B1 patent drawingFigure 2
  • EP3675992B1 patent drawingFigure 3

AI summary

The invention relates to a construction material mixer, in particular an asphalt or concrete mixer, consisting of a container (1) having at least one driven shaft (5) to which mixing arms (6) carrying blades (12) are fastened at intervals, the blades (12) being at a distance from the inner wall of the container (1), the mixing arms (6) being divided into an inner part (11), which is connected to the shaft (5), and an outer part (13), which carries the blades (12), and both parts being connectable to each other by means of an adjustable connection device (22). The invention is based on the fact that the connection device (22) is a snap connection device. A particular embodiment and a rapid blade replacement method are described.