Blower Vacuum Interlock Mechanism for Attachment-Safe Motor Start

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Solution Overview

Problem

Existing blower vacuum devices lack effective safety interlocks to prevent accidental activation of the motor when attachments are not properly secured, allowing objects or hands to potentially activate the impeller, leading to safety hazards.

Innovation Solution

A blower vacuum device with a housing, motor, and an interlock mechanism that includes a moveable cam surface and blocking plate, which prevents the actuating projection from activating the switch unless the attachment is correctly mounted, combined with a user-operated switch and electronic braking mechanism to stop the fan quickly when the attachment is removed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a simple button switch is used to activate the motor, then the device is easy to operate, but the safety protection is insufficient allowing accidental activation when attachments are removed

Engineering Contradiction:

Improveease of operationVSAvoidsafety protection

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent introduces an interlock mechanism as an intermediary between the attachment and the motor activation system. This mechanism includes a cam surface and blocking plate that physically mediate the interaction between the attachment state and the switch, preventing direct activation when the attachment is improperly secured.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The interlock mechanism automatically monitors the attachment state and controls motor activation without requiring additional user input. The system self-regulates by using the attachment's own positioning to control the blocking plate, which in turn controls switch accessibility, providing automatic safety protection.

Inventive Principle:

Principle #25Self-service

2Ease of operation

If the switch is exposed and accessible, then the device is easy to activate, but objects or hands can accidentally activate the impeller when the attachment is removed

Engineering Contradiction:

Improveaccessibility of switchVSAvoidaccidental activation hazard

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The blocking plate is designed to be dynamically positioned based on the attachment state. When the attachment is properly installed, the blocking plate moves to an unblocked position allowing switch activation. When the attachment is removed, the blocking plate automatically moves to a blocked position, dynamically adjusting accessibility based on safety conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The blocking plate serves as a physical intermediary that controls access to the switch. It mediates between the attachment state and the switch, preventing direct contact with the switch when the attachment is not properly secured, thereby eliminating the hazard of accidental activation.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If an interlock mechanism with blocking plate is added, then safety protection is improved, but the device complexity increases

Engineering Contradiction:

Improvesafety protectionVSAvoidinterlock mechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The interlock mechanism is segmented into distinct functional components: the cam surface, blocking plate, and switch. Each component has a specific function, and they work together in a modular fashion. This segmentation allows for easier manufacturing, assembly, and maintenance while achieving the safety function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces complex electronic safety systems with a purely mechanical interlock mechanism. The cam surface and blocking plate use simple mechanical geometry to achieve the safety function, avoiding the need for sensors, microcontrollers, or complex electronic circuits, thereby keeping the overall device complexity low.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Adaptability or versatility

If the attachment can be easily removed, then the device is versatile and easy to maintain, but the risk of accidental activation increases

Engineering Contradiction:

Improveattachment removabilityVSAvoidaccidental activation risk

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The interlock mechanism dynamically adjusts switch accessibility based on the attachment state. When the attachment is properly installed, the blocking plate permits switch activation. When the attachment is removed, the blocking plate automatically blocks the switch, dynamically preventing accidental activation while allowing easy attachment removal and reinstallation.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8918951B2Blower vacuum device

Publication Date: 2014.12.30 BLACK & DECKER CORP

AI summary

The present invention relates to a blower vacuum device and in particular to a blower vacuum device for use in the collection of garden debris. The device is preferably one which is operable in a blowing mode to generate an air stream for blowing the debris into piles and also operable in a vacuum mode to suck debris into the device.