Adjustable Locking Pliers Spring Segmentation

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Solution Overview

Problem

Existing adjustable locking pliers face difficulties in easily unlocking a tightly clamped object due to stiff springs, which can lead to an explosive release of energy and make it hard to adjust the gripping capacity, causing discomfort and potential damage.

Innovation Solution

The design incorporates a latch lock mechanism with a spring biased between the first and second pivots, allowing for automatic opening of the jaws when unclamped, and a trigger for disengagement, optimizing the spring for release and rotation of the movable jaw, with notched tracks for adjustable gripping capacity and tactile feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a stiff spring is used to maintain clamping force, then the clamping force is strong and reliable, but it causes explosive release of energy during unlocking and makes adjustment difficult

Engineering Contradiction:
Improveclamping forceVSAvoidease of unlocking
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The spring system is segmented into two separate springs: a first spring (torsion spring) that provides strong clamping force during the clamped state, and a second spring (compression spring) that assists during the unlocking process. This segmentation allows each spring to be optimized for its specific function, preventing the explosive release issue while maintaining strong clamping force.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic behavior to the spring system by using a compression spring that becomes active during unlocking. The compression spring is compressed during the transition from clamped to unlocked state, converting the potentially explosive elastic energy into controlled mechanical work that assists in opening the jaws gradually.

Inventive Principle:
Principle #15Dynamics

2Strength

If a stiff spring is used to maintain clamping force, then the clamping force is strong and reliable, but it requires excessive force for adjusting the gripping capacity

Engineering Contradiction:
Improveclamping forceVSAvoidease of adjustment
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The spring system is segmented into two separate springs: a first spring (torsion spring) that provides strong clamping force during the clamped state, and a second spring (compression spring) that assists during the unlocking process. This segmentation allows each spring to be optimized for its specific function, preventing the explosive release issue while maintaining strong clamping force.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic behavior to the spring system by using a compression spring that becomes active during unlocking. The compression spring is compressed during the transition from clamped to unlocked state, converting the potentially explosive elastic energy into controlled mechanical work that assists in opening the jaws gradually.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the latch lock mechanism is designed for strong locking, then the locking reliability is high, but it becomes difficult to unlock without explosive energy release

Engineering Contradiction:
Improvelocking reliabilityVSAvoidease of unlocking
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies preliminary action by compressing the second spring during the unlocking process before the jaws actually open. This pre-compression stores energy that is then released in a controlled manner to assist in opening the jaws, preventing explosive energy release while maintaining reliable locking during the clamped state.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces dynamic behavior to the spring system by using a compression spring that becomes active during unlocking. The compression spring is compressed during the transition from clamped to unlocked state, converting the potentially explosive elastic energy into controlled mechanical work that assists in opening the jaws gradually.

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 enhances the ease of unlocking by preventing explosive reactions, reduces the force needed for adjusting the gripping capacity, and provides a compact, ergonomic, and reliable operation with improved control over the locking pliers.

Implementation Method 1

a compression spring 52 which is bent in a U-shape between a pin 54 inside the handle 10 and an eyelet 56 behind the upper vertex of the movable jaw 14

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

The compression spring 52 tends to straighten and, in doing so, urges the eyelet 56 upwards and forwards with a force

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

Each window 22 has, on a forward facing side, a series of four notches 50a-50d. Each pair of mutually aligned notches 50a-50d is suitable for cradling the dowel 20

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2826595B1Adjustable locking pliers
Publication Date: 2019.05.29 STANLEY WORKS (EUROPE) GMBH
  • EP2826595B1 patent drawingFigure 1
  • EP2826595B1 patent drawingFigure 2
  • EP2826595B1 patent drawingFigure 3

AI summary

An adjustable locking pliers (102) comprising a stationary handle (110), a stationary jaw (108), an operating lever (124) and a movable jaw (114). The movable jaw is coupled by a jaw axis (120) which is selectively displaceable to alter the jaws' gripping capacity. The operating lever (124) is coupled to the movable jaw by a first pivot (126). The operating lever rear forms a movable handle (132). A spring (170) biases rotation of the movable jaw (114) about the jaw axis (130) away from the stationary jaw (108). An actuation rod (128) is coupled to the operating lever (124) by a second pivot (130) part way along the operating lever and coupled to the stationary handle by means of a third pivot (148). The actuation rod (128) and the operating lever (124) are prevented from passing beyond alignment of the first (126), second (130) and third (148) pivots during clamping.