Concave Guide Surfaces for Fastener Tilting in Handheld Tools

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Solution Overview

Problem

Existing setting tools with muzzle parts fail to ensure optimal positioning and guidance of fastening elements, particularly when there are only a few fasteners left in the magazine, leading to potential tilting or canting during the pressing process.

Innovation Solution

The setting tool features concave guide surfaces on the detection element facing the receiving space, which are parallel to the longitudinal direction and surround the receiving space by 120°-180°, providing a sufficient frictional connection to prevent tilting and canting of fasteners, and a pivotably mounted detection element for reduced friction and space-efficient design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If guide surfaces are arranged on the axially displaceable fastener guide, then the fastener guide can be simple in structure, but fasteners are not optimally positioned when the fastener guide is displaced, especially when there are only a few fasteners left in the magazine

Engineering Contradiction:
Improvefastener guide structureVSAvoidfastener positioning accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The guide surfaces are segmented between two separate components: the fastener guide and the detection element. The first guide surface is formed on the fastener guide, while the second and third guide surfaces are formed on the detection element. This segmentation allows the fastener guide to remain simple and displaceable, while the detection element provides additional guide surfaces that remain stationary relative to the receiving space, ensuring optimal fastener positioning even when the fastener guide is displaced during operation.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If the detection element is made stationary relative to the displaceable fastener guide, then fastener positioning is improved, but the device complexity increases

Engineering Contradiction:
Improvefastener positioning accuracyVSAvoidmuzzle part structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The detection element combines multiple functions into a single component: it serves as both a detection device for sensing fastener presence and as a guidance device through its second and third guide surfaces. By merging these functions, the patent avoids the need for separate detection and guidance components, thereby reducing overall device complexity while maintaining improved fastener positioning accuracy.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If guide surfaces surround the receiving space by 120°-180°, then optimal guidance and frictional connection are achieved, but the installation space requirement increases

Engineering Contradiction:
Improvefastener guidance reliabilityVSAvoiddetection element area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The second and third guide surfaces on the detection element are designed with curved geometries that together surround the receiving space by 120°-180° in the radial direction. This curved arrangement optimizes the frictional connection with the carrier segment of fasteners, preventing tilting or canting during the pressing process. The detection element is pivotably mounted on a bearing parallel to the longitudinal direction of the mouth part, which allows it to rotate into position and reduces the need for large installation space compared to a completely fixed arrangement.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 ensures reliable and optimal positioning and guidance of fasteners, preventing tilting or canting during the pressing process, even when there are few fasteners in the magazine, and allows for trouble-free pivoting of the detection element, enhancing the overall setting process.

Implementation Method 1

achieves a sufficient frictional connection with the carrier segment of the fasteners and thus prevents tilting or canting of a Recording space located fastener reliably prevented during the pressing process

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP1862262B1Handheld fastening tool
Publication Date: 2009.12.16 HILTI AG
  • EP1862262B1 patent drawingFigure 1
  • EP1862262B1 patent drawingFigure 2
  • EP1862262B1 patent drawingFigure 3~4

AI summary

The device has a detection element (31) e.g. lever, for a fastening unit (51) in a receiving space. One of the guidance surfaces for the fastening unit is arranged on the side facing the receiving space, where the guidance surface runs parallel to a longitudinal direction of a muzzle part. Concave guidance surfaces (35, 36) are arranged at the side facing the receiving space. The surfaces (35, 36) run parallel to the longitudinal direction, and are opposite in the longitudinal direction adjacent to the guidance surface (34).