Operating Drum Ring Support for Chip-Resistant Reciprocating Tools

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Solution Overview

Problem

Reciprocating cutting tools face issues with deteriorating movement of the operating drum due to chip entry between the operating drum and the housing, leading to reduced operability and potential failure in blade attachment and detachment operations.

Innovation Solution

The design incorporates a power transmission housing with ring members to rotatably hold the operating drum, and the use of ring springs and a tension spring to reduce contact area and prevent chip entry, along with a release unit that includes a release drum and ring springs to facilitate smooth rotation and prevent chip accumulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the operating drum is rotatably held directly on the power transmission housing, then the structure is simple, but chips enter between the operating drum and housing causing deteriorating movement

Engineering Contradiction:

Improveoperating drum movement reliabilityVSAvoidchip entry between operating drum and housing

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A ring member is introduced as an intermediary component between the operating drum and the power transmission housing. The ring member rotatably holds the operating drum while being in contact with the housing, preventing direct contact and eliminating the gap where chips could enter, thus resolving the chip entry issue while maintaining simple structure

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The ring member acts as a protective barrier that isolates the operating drum from the housing environment, preventing chips from entering the contact interface and causing deteriorating movement

Inventive Principle:

Principle #30Flexible shells and thin films

2Object-affected harmful factors

If ring members are used to rotatably hold the operating drum, then chip entry is prevented, but the device complexity increases

Engineering Contradiction:

Improvechip entry preventionVSAvoidnumber of ring members and springs

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The ring member serves multiple functions: it rotatably holds the operating drum, prevents chip entry between the drum and housing, and works with spring members to maintain proper contact pressure. This multi-functionality reduces the need for separate components for each function

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of operation

If the operating drum rotates to attach or detach the tip tool, then the blade can be quickly changed, but chip accumulation causes deteriorating movement

Engineering Contradiction:

Improveblade attachment and detachmentVSAvoidoperating drum rotation smoothness

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The ring member serves as a protective barrier between the operating drum and the housing environment, preventing chips from entering the rotation interface and causing deteriorating movement, thus maintaining smooth rotation for reliable blade attachment and detachment

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11839925B2Reciprocating cutting tool

Publication Date: 2023.12.12 MAKITA CORP

AI summary

A reciprocating cutting tool reduces deteriorating movement of an operating drum due to entry of chips between the operating drum and a housing. A reciprocating cutting tool includes a motor, a slider being rod-like and extending in a front-rear direction, a reciprocation converter that converts rotation of the motor to reciprocation in the front-rear direction and transmits the reciprocation to the slider, a power transmission housing accommodating the reciprocation converter, a tip tool holder at a front end of the slider to detachably receive a tip tool, and an operating drum operable to attach or detach the tip tool with the tip tool holder through rotation. The operating drum is rotatably held on the power transmission housing with one or more ring members.