Spool-Valve Biasing for Sausage Packaging Clipping

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Solution Overview

Problem

The existing clipping devices for sausage-shaped product packaging machines face issues with unreliable operation due to sudden disruptions in compressed air supply, leading to unintended activation of the punch and potential damage to the packaging casing or machine components.

Innovation Solution

Incorporating a preventing device within the control unit that ensures the spool-piston remains in a closed position when fluid supply is disrupted, preventing unintended fluid connection and ensuring safe operation by using a spring, magnet, or fluid pressure to maintain the spool-piston in its closed position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a fluid-driven clipping device is used to automatically close packaging casings, then productivity and automation are improved, but reliability deteriorates due to unintended activation from fluid supply disruptions

Engineering Contradiction:
Improveautomated closing operationVSAvoidunintended activation risk
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The spool-piston is designed with a biasing mechanism (spring, magnet, or fluid pressure) that continuously urges it toward the closed position, creating a preliminary counter-action against any unintended opening forces. This ensures that even if fluid supply is disrupted or contaminated, the piston remains in the safe closed position and cannot accidentally activate the punch.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The system performs a preliminary check by requiring intentional activation forces (such as specific solenoid signals or manual intervention) to overcome the biasing mechanism and move the spool-piston from closed to opened position. This preliminary action requirement prevents spontaneous or accidental activation while maintaining automated operation.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If the spool-piston is allowed to move freely between opened and closed positions for control flexibility, then ease of operation is improved, but harmful factors increase due to potential damage from unintended activation

Engineering Contradiction:
Improvecontrol flexibilityVSAvoiddamage to packaging casing
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The biasing mechanism continuously applies a counter-force to prevent unintended movement of the spool-piston toward the opened position. This preliminary anti-action ensures that only deliberate, controlled forces can overcome the bias and activate the punch, thereby preventing damage to packaging casings while maintaining operational flexibility.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The spool-piston acts as an intermediary element between the fluid supply system and the punch activation mechanism. By incorporating the biasing mechanism within the spool-piston assembly, the system introduces a safety intermediary that filters out unintended activation signals while allowing legitimate control commands to pass through, thus preventing harmful effects.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Power

If compressed air supply is used to drive the punch, then power and speed are improved, but reliability deteriorates due to sensitivity to supply disruptions

Engineering Contradiction:
Improvepunch driving forceVSAvoidsensitivity to fluid supply disruption
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The control system for the punch activation is extracted from direct dependence on the main compressed air supply. By using a spool-piston with biasing that can maintain its position independently of fluid pressure fluctuations, the system separates the power transmission function from the control function, making the control mechanism insensitive to supply disruptions while retaining high power delivery.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The biasing mechanism (spring, magnet, or pre-charged fluid system) acts as a cushioning element that absorbs and compensates for disruptions in the compressed air supply. This beforehand cushioning ensures that temporary pressure drops, contaminants, or supply interruptions do not cause unintended activation, while the system maintains its ability to deliver full power when properly activated.

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

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 solution prevents accidental activation of the punch, thereby avoiding damage to the sausage-shaped products and the clipping machine, ensuring reliable handling and operation of the clipping device.

Implementation Method 1

using a spring, magnet, or fluid pressure to maintain the spool-piston in its closed position

Methodology Applied
Scientific EffectMagnetism: Magnetism

Implementation Method 2

using a spring, magnet, or fluid pressure to maintain the spool-piston in its closed position

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

using a spring, magnet, or fluid pressure to maintain the spool-piston in its closed position

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP2380444B1Automatically sealable spool-valve
Publication Date: 2014.10.08 POLY CLIP SYST
  • EP2380444B1 patent drawingFigure 1
  • EP2380444B1 patent drawingFigure 2
  • EP2380444B1 patent drawingFigure 3

AI summary

The present invention concerns a clipping-device for closing a tubular packaging casing in a clipping-machine for producing sausage-shaped products, in particular sausages, by applying at least a closure means, in particular a closure clip, to the tubular packaging casing. The clipping-device comprises a punch and die assembly (61) for attaching and closing the closure means (C) on the tubular packaging casing. Beyond that the clipping-device also comprises a fluid-drive assembly (F) for driving the punch and die assembly (61), including at least one punch drive piston (62) being reciprocally movable within a punch drive cylinder (63), wherein the punch drive piston is reversibly moving at least a punch of the punch (65) and die assembly (61) between an opened and a closed position, with the opened position being the maximum displacement between the punch (65) and the die (66) of the punch and die assembly, and with the closed position being the minimum displacement between the punch and the die of the punch and die assembly. Furthermore, a control unit (70,1070) comprising an inlet fluid conduct (110,1110), an outlet fluid conduct (120,1120), a control unit housing (71,1071) as well as a spool-valve (80), which is accommodated within the control unit housing and which includes a spool-piston (85,1085), having a first spool-piston end (85a) and a second spool-piston end (85b), reciprocally movable within a spool-cylinder, for controlling the fluid-drive assembly. The spool-piston is movable between an opened and a closed position, with the opened position enabling a fluid to flow between a fluid-source (S) and the fluid-drive assembly, and with the closed position preventing the fluid to flow between the fluid-source and the fluid-drive assembly. Also, the control unit comprises a preventing device (150,1150) for preventing an unintended fluid connection between the fluid-source (S) and the fluid-drive assembly (F).