Stitching Head Drive with PLC Timing for Staple Placement

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Solution Overview

Problem

Conventional stapling mechanisms using an eccentric mechanism result in inadequate staple pin operation timing, leading to poor quality and increased rejection rates, especially when handling variable book thicknesses, and are limited to low production speeds.

Innovation Solution

A stapling unit with an improved stitching head drive apparatus that utilizes a bunch sensor to control the movement of the stitching head through a lever operating device, which includes a toggle release lever and a CAM or electrical actuator to synchronize the stapling process, ensuring precise staple pin placement and minimizing rejections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If an eccentric mechanism is used to drive the stitching head, then the structure is simple, but the staple pin operation timing is inadequate and quality deteriorates

Engineering Contradiction:

Improvedrive mechanism structureVSAvoidstaple pin operation timing

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent replaces the conventional eccentric mechanical mechanism with a programmable logic controller (PLC) based control system. The PLC receives signals from a bunch sensor and controls a lever operating device (pneumatic cylinder or electric actuator) to drive the stitching head, substituting mechanical timing with electronic control for precise staple pin operation timing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a lever operating device as an intermediary between the control system and the stitching head drive. This device includes a toggle release lever and pivot lever mechanism that translates electronic control signals into precise mechanical motion, mediating between the PLC and the stitching head to achieve accurate timing.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If an eccentric mechanism is used, then the device complexity is low, but the production speed is limited

Engineering Contradiction:

Improvedrive mechanism structureVSAvoidproduction speed

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The patent replaces the mechanical eccentric mechanism with an electronically controlled system using PLC, bunch sensor, and lever operating device. This substitution enables high-speed operation by allowing programmable control of the stitching head movement, achieving production speeds of five books per second or more.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If an eccentric mechanism is used, then the structure is simple, but the staple pin placement quality deteriorates

Engineering Contradiction:

Improvedrive mechanism structureVSAvoidstaple pin placement quality

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent replaces the mechanical timing mechanism with an electronic control system that uses a bunch sensor to detect book presence and a PLC to precisely control the lever operating device. This ensures accurate staple pin placement by synchronizing the stitching head movement with the actual book position, eliminating the timing errors inherent in eccentric mechanisms.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Device complexity

If the stitching head moves according to eccentric path, then the mechanism is simple, but the cycle time increases

Engineering Contradiction:

Improvedrive mechanism structureVSAvoidcycle time

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

The patent replaces the fixed eccentric path mechanism with a programmable control system that optimizes the stitching head movement cycle. The PLC controls the lever operating device to achieve faster acceleration and deceleration phases, reducing the overall cycle time while maintaining precise control, thereby increasing production speed to five books per second or more.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

The solution provides controllable movement of the stitching head, reducing staple pin rejections and improving cycle time, resulting in quicker and higher-quality stapling operations.

Implementation Method 1

The stitching head is driven by a CAM drive through a lever mechanism

Methodology Applied

Scientific EffectCAM mechanism: Cam

Data Source

PatentUS12434500B2Stapling unit with an improved stitching head drive apparatus

Publication Date: 2025.10.07 PATEL UDAYKUMAR CHHABILDAS

AI summary

A stapling unit with an improved stitching head drive apparatus includes a bunch sensor that senses the absence of the bunch of sheets and send a signal to the PLC, which actuates a lever operating device. The lever operating device opens the toggle lever by pushing the toggle release lever to disengage the driving lever from the pivot lever. The disengagement of the toggle lever with the pivot lever and the driving lever results in free pivotal movement of the pivot lever and the driving lever will not transfer the motion to the shaft which is responsible to drive the stitching head. Thus, the controllable movement of the stitching head results in improved cycle time of machine and minimum rejection.