Adaptive Ejector Comb for Sheet Processing Machines

Solution Overview

Problem

At high throughput rates, such as 10,000 sheets per hour, the gripper bar in sheet processing machines deforms due to centrifugal force, disrupting the interception between the gripper bar and the static ejector, which can lead to failure in on-the-fly waste removal functionality.

Innovation Solution

An ejector member with a comb that can adapt to low and high throughput positions by adjusting its curvature, with the center set back further in the high-throughput position to mimic the gripper bar's shape, ensuring the grippers can pass between the teeth without collision, and featuring deformable zones and articulations for flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the gripper bar operates at high throughput rates, then productivity is improved, but the gripper bar deforms under centrifugal force causing ejection failure

Engineering Contradiction:

Improvethroughput rateVSAvoidejection functionality

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The ejector comb is made adjustable between different positions to adapt to varying operational conditions. At high throughput rates, the comb position is adjusted to account for gripper bar deformation, ensuring reliable ejection. This dynamic adjustment resolves the contradiction by allowing the system to maintain ejection functionality across different productivity levels.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes the position parameter of the ejector comb based on throughput rate. By adjusting the comb's position relative to the gripper bar path, the system compensates for centrifugal deformation at high speeds while maintaining proper ejection geometry, thus preserving reliability across varying productivity conditions.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the comb is positioned for high throughput operation, then ejection reliability at high speed is improved, but interception geometry becomes incorrect at low throughput

Engineering Contradiction:

Improveejection at high throughputVSAvoidinterception geometry

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The ejector comb is made adjustable between different positions to adapt to varying operational conditions. At high throughput rates, the comb position is adjusted to account for gripper bar deformation, ensuring reliable ejection. This dynamic adjustment resolves the contradiction by allowing the system to maintain ejection functionality across different productivity levels.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The adjustable comb mechanism serves multiple functions: it provides the correct interception geometry for both low and high throughput operations. By being repositionable, a single comb structure universalizes the ejection system across different operating conditions, eliminating the need for separate configurations.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If the comb is positioned for low throughput operation, then interception geometry is correct at low speed, but ejection fails at high throughput due to gripper bar deformation

Engineering Contradiction:

Improveinterception geometryVSAvoidejection at high throughput

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The ejector comb is made adjustable between different positions to adapt to varying operational conditions. At high throughput rates, the comb position is adjusted to account for gripper bar deformation, ensuring reliable ejection. This dynamic adjustment resolves the contradiction by allowing the system to maintain ejection functionality across different productivity levels.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The comb position is adjusted in advance based on the expected throughput rate before ejection occurs. This preliminary positioning ensures that when high throughput operation begins and centrifugal force deforms the gripper bar, the comb is already in the correct position to maintain proper interception geometry and reliable ejection.

Inventive Principle:

Principle #10Preliminary action

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

Ensures reliable on-the-fly ejection of waste at both low and high throughput rates by matching the comb's curvature to the gripper bar's shape, preventing collisions and maintaining efficient waste removal.

Implementation Method 1

the gripper bar may deform under the effect of the centrifugal force

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentUS11007662B2Ejector member and machine for processing sheet-form elements

Publication Date: 2021.05.18 BOBST MEX SA

AI summary

An ejector member (2) for removing waste from sheets on the fly in a machine (1) for processing sheet-form elements includes a comb (4) having a plurality of teeth (10). The comb (4) is configured to be able to adopt a low-throughput first position and at least one high-throughput second position. The center of the comb (4) is set back with respect to the lateral ends of the comb (4) in the high-throughput second position. The center of the comb (4) is set back further in the high-throughput second position than in the low-throughput first position. Also relates a machine for processing sheet-form elements including such an ejector member.