Grease Cap Locking Arms and Sealing Mechanism

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Solution Overview

Problem

Existing power tool grease caps fail to securely lock onto the grease supply inlet, leading to potential grease leakage and inefficient lubrication.

Innovation Solution

A grease cap design featuring circumferential protuberances, locking arms, and a sealing mechanism that engages with the inlet port to prevent rotation and ensure a secure, locked position, thereby preventing leakage and facilitating easy assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a simple cap design is used for the grease supply inlet, then the device complexity is reduced and ease of manufacture is improved, but the reliability deteriorates due to potential grease leakage and inefficient securing

Engineering Contradiction:
Improvegrease leakage preventionVSAvoidcap structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cap is segmented into multiple functional components: a body portion for covering the inlet, locking arms with protrusions for securing, and finger tabs for operation. This segmentation allows each component to perform its specific function efficiently while maintaining overall reliability without excessive complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the cap have specialized features tailored to their functions: the body portion has a sealing surface for grease leakage prevention, the locking arms have protrusions for engagement with recesses, and the finger tabs have ergonomic shaping. This local quality ensures high reliability at each critical interface without requiring complex overall design

Inventive Principle:
Principle #3Local quality

2Reliability

If a secure locking mechanism is implemented to prevent grease leakage, then the reliability is improved, but the ease of operation deteriorates due to difficulty in assembly and disassembly

Engineering Contradiction:
Improvesecuring efficiencyVSAvoidcap assembly and disassembly
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The locking mechanism is designed to be dynamic rather than fixed: the locking arms can rotate between locked and unlocked positions, and the protrusions can engage or disengage from the recesses. This dynamic design provides secure locking when engaged while allowing easy operation when needed

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The cap design incorporates self-aligning features where the protrusions on the locking arms automatically engage with the recesses in the housing when the cap is rotated into position. The finger tabs are positioned to naturally guide user fingers for rotation, making the securing process self-explanatory and easy to perform without complex procedures

Inventive Principle:
Principle #25Self-service

3Ease of operation

If the cap is designed to be easily removable for grease injection, then the ease of operation is improved, but the reliability deteriorates due to potential rotation and misalignment

Engineering Contradiction:
Improvegrease injection accessVSAvoidcap position stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The locking arms and protrusions are pre-configured to engage automatically when the cap is rotated into the correct position. The finger tabs are pre-positioned to guide the rotation motion, ensuring the cap aligns properly with the inlet before locking occurs. This preliminary action prevents misalignment while maintaining ease of operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The locking mechanism uses asymmetric protrusions and recesses that only engage in one specific orientation. This asymmetric design prevents the cap from rotating to incorrect positions while still allowing easy removal by rotating in the opposite direction, thus maintaining both reliability and ease of operation

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2889109B1Grease cap
Publication Date: 2017.06.14 BLACK & DECKER CORP
  • EP2889109B1 patent drawingFigure 1
  • EP2889109B1 patent drawingFigure 2
  • EP2889109B1 patent drawingFigure 3

AI summary

According to an aspect of the present invention there is provided a cap for closing an inlet port for introducing lubricant into a power tool, the power tool having an outer casing, the cap comprising, a top portion, a stopper portion, and at least one engaging member configured to engage the inlet port when the cap is displaced to a locked position. The top portion comprises at least one protrusion for cooperating with the outer casing of the power tool to fix the cap in said locked position.