Pliers With Linear Jaw Adjustment and Torque-Supporting Overlap

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Solution Overview

Problem

Existing pliers designs lack ergonomic handling and functional reliability, particularly in adjusting jaw width, with limitations in adjustability and torque transmission.

Innovation Solution

The design features an elongated overlapping area between pliers legs, allowing for ergonomic adjustment of jaw width without pivoting, enhanced torque transmission through aligned tooth groups, and a slimmed-down structure for improved handling in difficult-to-access areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the pliers legs are designed with a conventional overlapping area, then the structure remains compact, but the adjustment of jaw width requires pivoting the pliers legs to the largest possible open position, which reduces ease of operation

Engineering Contradiction:
Improveease of jaw width adjustmentVSAvoidadjustment mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The hinge pin is made movable within the longitudinal slot, allowing dynamic repositioning of the pivot point along the slot. This enables the pliers to adjust jaw width by translating the hinge pin linearly rather than requiring full pivoting motion, thereby improving ease of operation while maintaining a compact structure

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The adjustment mechanism utilizes a longitudinal slot that extends in a direction perpendicular to the conventional pivoting arc. By moving the hinge pin along this new dimensional path (linear translation along the slot), the patent eliminates the need to pivot to the largest open position, transforming a rotational adjustment into a linear sliding adjustment

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

2Strength

If the longitudinal slot has a small overlapping area, then the pliers structure remains slim and compact, but the torque transmission capability is reduced

Engineering Contradiction:
Improvetorque transmission capabilityVSAvoidoverall pliers length
Core Design Contradiction:
StrengthVSLength of stationary object

Solution Approach 1:

The longitudinal slot is designed with an elongated overlapping area that is concentrated in the region where the pliers legs overlap. This localized enhancement of the overlapping area provides sufficient torque transmission capability exactly where needed (in the overlap region), while keeping the rest of the pliers structure slim and compact

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The overlapping area incorporates both the movable pliers leg with the longitudinal slot and the fixed pliers leg with corresponding structural features. This composite design creates an extended overlapping region that enhances torque transmission through increased surface area and structural interlocking, while the overall pliers length remains constrained by the compact arrangement of these composite components

Inventive Principle:
Principle #40Composite materials

3Productivity

If the hinge pin is moved out of toothed engagement by pivoting to the largest open position, then jaw width adjustment is achieved, but the adjustment process becomes time-consuming and reduces productivity

Engineering Contradiction:
Improveadjustment speedVSAvoidtime for jaw width adjustment
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The hinge pin is pre-positioned within the longitudinal slot at a location that allows direct linear translation to the desired adjustment position. This preliminary arrangement eliminates the need to first pivot to the largest open position, enabling direct and quick adjustment of jaw width by simply sliding the hinge pin along the slot, thereby reducing adjustment time and increasing productivity

Inventive Principle:
Principle #10Preliminary action

4Ease of operation

If the pliers are designed with a conventional structure, then manufacturing is straightforward, but handling in difficult-to-access areas becomes difficult

Engineering Contradiction:
Improvehandling in tight spacesVSAvoidmanufacturing complexity
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The pliers structure is segmented into distinct functional zones: the overlapping area with the longitudinal slot for adjustment, the handle sections for grip, and the jaws for workpiece engagement. This segmentation allows the overlapping area to be optimized for slimness and maneuverability in tight spaces, while the handle and jaw sections maintain conventional robust designs that are easy to manufacture

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4319942B1Pliers
Publication Date: 2025.08.13 KNIPEX WERK C GUSTAV PUTSCH KG
  • EP4319942B1 patent drawingFigure 1~2
  • EP4319942B1 patent drawingFigure 3~4
  • EP4319942B1 patent drawingFigure 5~6

AI summary

The invention relates to pliers (1) having two plier arms (3 and 4) which cross one another by means of a joint bolt (2) having a joint bolt axis (x) and of which one plier arm (4) may be regarded as movable and the other (3) as stationary; gripping portions (8 and 9) are formed on one side of the joint bolt (2) and jaws (5 and 6) which co-operate as the mouth (7) of the pliers are provided on the other side of the joint bolt (2); furthermore, the movable plier arm (4) has a longitudinal slot (13) with a toothing (16) and the joint bolt (2) located in a receptacle (12) is movable out of a toothing engagement and the movable arm (4) penetrates the stationary plier arm (3); the longitudinal slot (13) has an extent (S) which, with the pliers (1) closed, runs transversely to an orientation of the plier arms (3 and 4) at the gripping end. In order to design pliers of the type in question for safe handling and operation, according to the invention the toothing (16) can be overrun by depression of the joint bolt (2) for adjustment of a mouth opening width (w); the penetrating plier arm (4) has an elongate overlap region (U) in which the penetrating plier arm (4) is overlapped on both sides by the penetrated plier arm (3); furthermore, the overlap region extends (U) substantially at right angles to an adjustment direction (r) of the joint bolt (2) in the longitudinal slot (16), having a width (g), which corresponds to 0.5 times or more of the maximum degree of adjustment (f), and having a length (d), which corresponds to 2 times or more of the maximum degree of adjustment (f).