Actuating Lever Pliers with Curved Slot Locking Mechanism

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Solution Overview

Problem

Existing water pump pliers require two hands to adjust and can be cumbersome to use, especially in confined spaces, due to their top-heaviness and complex handling mechanisms, which increases the effort required for operation and limits one-handed operation.

Innovation Solution

The design features a locking piece that can be displaced translatorily within a curved elongated hole, with a sawtooth profile for positive engagement, and an actuating lever that allows for easy manual operation, reducing the force needed to unlock the locking piece, and incorporates a truss structure for weight optimization and material savings, enabling easier handling and adjustment with less physical effort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the locking piece is held in a locking position with a compressive force via a leaf spring to improve adjustment possibility, then the adjustment capability is improved, but the handling becomes more difficult and requires high skill level

Engineering Contradiction:
Improveadjustment capabilityVSAvoidhandling ease
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

An actuating lever is introduced as an intermediary element between the user's hand and the locking piece. The lever pivots about a deflection point and transfers the user's input force to the locking piece, enabling easy one-handed operation without requiring direct manual manipulation of the locking mechanism itself

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The locking piece is designed to move along a curved path in a curved slot rather than linear motion. This curved trajectory allows the locking piece to be displaced from the locking position to the release position while maintaining proper mechanical engagement and spring force application throughout the motion

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Strength

If the pliers arms are made solid in the transition area to increase strength, then the strength is improved, but the dead weight increases and handling becomes more difficult

Engineering Contradiction:
Improvestrength in transition areaVSAvoiddead weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The transition area of the pliers arms is segmented into a truss structure consisting of multiple discrete members connected at joints. This segmentation allows the structure to maintain strength through geometric configuration rather than continuous material, significantly reducing dead weight while preserving load-bearing capacity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pliers arms combine different material properties and structural configurations - the truss structure uses lightweight materials arranged for optimal strength-to-weight ratio, while other areas may use different materials or solid constructions where strength is prioritized over weight

Inventive Principle:
Principle #40Composite materials

3Reliability

If two hands are required to open both pliers arms wide for unlocking, then the unlocking mechanism can be operated, but the operation becomes more complex and time-consuming

Engineering Contradiction:
Improveunlocking mechanism operationVSAvoidoperation complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The actuating lever serves as a mechanical intermediary that amplifies the user's single-handed input force and translates it into the necessary motion to displace the locking piece along its curved path, enabling reliable unlocking with one hand

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The locking mechanism transitions from a static two-handed operation to a dynamic one-handed operation using the pivoting lever. The lever's rotation about the deflection point creates dynamic motion that efficiently moves the locking piece from the locking position to the release position

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 design simplifies the handling of water pump pliers by allowing one-handed adjustment with reduced physical effort, enhancing usability in confined spaces while maintaining strength and reducing material costs through optimized weight distribution and structural design.

Implementation Method 1

an actuating lever (18) which, when actuated, displaces a locking piece (19) in an axial direction so that the locking piece (19) is moved from a locking position to a release position

Methodology Applied
Scientific EffectLever: Lever

Implementation Method 2

an actuating lever (18) which, when actuated, displaces a locking piece (19) in an axial direction... arranged on the water pump pliers (1), which, when actuated, displaces a locking piece (19)

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Implementation Method 3

a spring (38), in particular a helical compression spring, is arranged on the actuating lever (18) and exerts a spring force on the actuating lever (18) on the locking piece (19)

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 4

with a sawtooth profile (16) for positive engagement

Methodology Applied
Scientific EffectMechanical Fastener: Mechanical Fastener

Data Source

PatentEP2636489B1Pliers with actating lever
Publication Date: 2014.12.03 HAZET WERK HERMANN ZERVER GMBH & CO KG
  • EP2636489B1 patent drawingFigure 1~2
  • EP2636489B1 patent drawingFigure 3~6
  • EP2636489B1 patent drawingFigure 7~8

AI summary

The pliers i.e. water pump pliers (1), have forge-technical pliers arms (2, 3) rotatably connected with each other over a rotational axis (4). A saw tooth profile (16) is formed in an oblong hole (15). A locking part (19) is translatory moved in a release position in the hole and lockably arranged in a locking position by positive engagement in the profile. The locking part is held in the locking position by a spring force and moved from the lock position into the release position against the spring force by an actuating lever (18).