Pliers Jaw Tooth Geometry for Tilt-Free Sheet Gripping

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Solution Overview

Problem

Existing pliers designs fail to securely grip sheet-like workpieces without tilting, especially when the thickness exceeds a certain material limit, due to uneven tooth distribution and orientation in the working areas.

Innovation Solution

The design incorporates first and second toothed areas with convex and flat envelope surfaces, where the convex surface's bulging point is centered in the second toothed area, allowing for secure, tilt-free gripping by ensuring the tooth tips of one area can dip into the gaps of the other, with third and fourth toothed areas separated by a hole structure for additional gripping options.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional parallel toothed areas are used in pliers, then the structure is simple and manufacturing is easy, but the pliers cannot securely grip sheet-like workpieces without tilting when thickness exceeds a certain limit

Engineering Contradiction:
Improvesecure gripping of sheet-like workpiecesVSAvoidtoothed area configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by configuring the first toothed area with a flat envelope surface and the second toothed area with a convex envelope surface. This asymmetric design causes the tooth tips to contact the workpiece at different locations, creating a tilting moment that prevents workpiece tilting during gripping. The convex envelope surface of the second toothed area specifically addresses the problem of securing thicker sheet-like workpieces by distributing contact forces more effectively.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If the convex envelope surface point is positioned differently in the second toothed area, then the gripping force distribution changes, but optimal tilt-free gripping for various material thicknesses cannot be achieved

Engineering Contradiction:
Improvetilt-free grippingVSAvoidpositioning of convex envelope surface point
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by optimizing the position of the convex envelope surface point within the second toothed area. This positional parameter is specifically configured to generate an optimal tilting moment that counteracts workpiece tilting. The parameter optimization ensures that for sheet-like workpieces up to a predetermined thickness, the gripping force is distributed in a way that maintains tilt-free gripping while accommodating variations in material thickness.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If only two toothed areas are provided in the pliers jaws, then the device structure is simple, but additional gripping options for different workpiece types and thicknesses are limited

Engineering Contradiction:
Improvegripping options for different workpiecesVSAvoidnumber of toothed areas
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the pliers jaws into multiple toothed areas (first, second, third, and fourth toothed areas) with different configurations. The first and second toothed areas have different envelope surfaces (flat and convex), while the third and fourth toothed areas provide additional gripping options. This segmentation allows the pliers to handle different workpiece types and thicknesses by selecting appropriate toothed areas, enhancing versatility without significantly increasing overall device complexity.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3411187B1Pliers having two pliers handles
Publication Date: 2021.04.07 KNIPEX WERK C GUSTAV PUTSCH KG
  • EP3411187B1 patent drawingFigure 1~2
  • EP3411187B1 patent drawingFigure 3
  • EP3411187B1 patent drawingFigure 4

AI summary

The invention relates to pliers (1) having two pliers handles (2, 3) guided such that they cross one another in a joint region having a stationary joint bolt (8), wherein gripping regions are formed on the pliers handles (2, 3) on one side of the joint region, and working regions (9, 10) are formed on free ends of the pliers handles (2, 3) on the other side, said working regions extending to form a pliers jaw (M), wherein the working regions (9, 10) also have first and second toothed regions (16 and 17) that come into contact when the pliers jaw (M) is closed, and the opposing first and second toothed regions (16, 17) are shaped differently in the longitudinal extension thereof. In order to advantageously further improve pliers of this type, in particular in relation to the configuration of the first and/or second toothed regions, in the first toothed region (16), in a sequence in the longitudinal extension of the pliers handle (2, 3), the tooth tips (22) end in a surrounding surface (23) that is flat in the longitudinal section and in contact with same, and the tooth tips (22) of the opposing second toothed region (17) end in a surrounding surface (30) that is convex in the longitudinal section and in contact with same.