Pincers With Protected Guide Mechanism

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Solution Overview

Problem

Existing pliers, particularly water pump pliers, pose a risk of user injury due to potential pinching during adjustment and operation, as they lack effective protection for the movable jaw areas and often suffer from asymmetrical force distribution leading to deformation under heavy loads.

Innovation Solution

The design features a longitudinal slot in the first pliers arm with a guide lug and flat bearing surfaces, a pivot pin guided in a slot parallel to the forced guidance, and a latching mechanism with teeth for coarse adjustment, ensuring protected guidance and symmetrical force distribution, along with a preloaded spring for enhanced safety and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the movable jaw is freely adjustable without protection, then the ease of operation is improved, but the safety of the user deteriorates due to pinching risk

Engineering Contradiction:
Improveease of adjustmentVSAvoidpinching injury risk
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

A protective cover is introduced as an intermediary element that encloses the movable jaw and guide slot. This cover allows the adjustment mechanism to remain accessible while physically blocking the harmful pinching area, thus mediating between ease of operation and user safety.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The protective cover is designed as a flexible enclosure that can accommodate the movable jaw's range of motion while maintaining a safety barrier. The cover follows the contours of the jaw mechanism, providing protection without restricting the adjustment function.

Inventive Principle:
Principle #30Flexible shells and thin films

2Device complexity

If asymmetrical force distribution is allowed, then the device complexity is reduced, but the reliability deteriorates due to deformation under heavy loads

Engineering Contradiction:
Improvestructural simplicityVSAvoiddeformation resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The guide slot is designed with an asymmetrical configuration where the first bearing surface is larger than the second bearing surface. This asymmetrical design intentionally creates a force distribution pattern that prevents deformation under heavy loads while maintaining structural simplicity, as the asymmetry itself is the functional feature rather than a complication.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

Different regions of the guide slot are given different bearing surface areas to create localized force distribution characteristics. The larger first bearing surface handles compressive forces while the smaller second bearing surface manages tensile forces, providing reliable force distribution without requiring complex structural reinforcements.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If the movable jaw is fully enclosed for protection, then the safety is improved, but the ease of operation deteriorates due to restricted access

Engineering Contradiction:
Improvepinching injury riskVSAvoidaccessibility for adjustment
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The protective cover is designed to be dynamically accessible, allowing the user to open or move the cover when adjustment is needed. The cover can be quickly opened to expose the movable jaw for adjustment and then closed to provide protection during operation, providing both safety and ease of operation through dynamic accessibility.

Inventive Principle:
Principle #15Dynamics

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

This configuration significantly reduces the risk of user injury by protecting the movable jaw area and distributing force evenly, enhancing the pliers' stability and service life by preventing deformation and accidental release of the locking mechanism.

Implementation Method 1

They work according to the leverage principle. Two double-sided levers are connected to each other by a joint. As a rule, the handles form the longer lever arms, and the shorter lever arms form the pliers head. According to the law of the lever, the manual force applied to the handles is increased and transferred to a workpiece by means of the pliers head.

Methodology Applied
Scientific EffectLever principle: Lever

Data Source

PatentEP1829647B1Pincers with protected guide
Publication Date: 2014.04.02 EDUARD WILLE GMBH & CO KG
  • EP1829647B1 patent drawingFigure 1
  • EP1829647B1 patent drawingFigure 2
  • EP1829647B1 patent drawingFigure 3

AI summary

The invention relates to pliers (10) with variable jaw opening, in particular water pump pliers, comprising a first and a second plier arm (12, 14) pivotably connected to each other about a pivot pin (28). The first plier arm (12) has an integrally formed jaw (26). A jaw (30) movable about a joint (34) is provided on the second plier arm (14). The movable jaw (30) of the second plier arm (14) has guide means (42, 70) by which the movable jaw (30), together with the second plier arm (14), is adjustable within a positive guide (42, 70) of the first plier arm (12). A locking mechanism (46) is provided for engaging the jaw, which holds the movable jaw (30) with the second plier arm (14) in a locking position for coarse adjustment.