Setting Tool Braking Element for Early Recoil Deceleration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing nail setting devices experience excessive recoil due to mis-setting or over-energy conditions, which can be dangerous and lead to injuries, and current solutions for controlling recoil are either ineffective or lead to premature wear and damage to the device.

Innovation Solution

A working tool with a pressure sensor and pressure spring system that transitions from driving mode to braking mode upon lifting from the surface, utilizing a braking element to decelerate the recoil through direct contact with the working piston, reducing recoil energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a nail that is too long is used or driven directly into a hard surface, then the embedment depth is maintained, but the piston is slowed down considerably and excessive recoil occurs

Engineering Contradiction:
ImprovesafetyVSAvoidrecoil
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The braking element is positioned to engage with the piston before the piston completes its full stroke, applying a counteracting force that prevents excessive recoil. This preliminary braking action occurs during the piston's deceleration phase, stopping the harmful recoil motion before it can cause damage or injury.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The braking element acts as an intermediary between the piston and the tool housing, absorbing and dissipating the excess energy from the piston's motion. This intermediary component prevents the direct transmission of harmful recoil forces to the tool structure and user.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If an elastic ring is used to cushion the piston, then piston energy is dissipated, but the ring body wears excessively and can be damaged if wear goes undetected

Engineering Contradiction:
Improvepiston energy dissipationVSAvoidcomponent durability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The braking element is designed as a wear-resistant component that can withstand repeated contact with the piston. Unlike the elastic ring that degrades over time, the braking element maintains its structural integrity and braking capability throughout the tool's service life, eliminating the reliability concerns associated with wear detection.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If the piston collar diameter is increased to prevent premature damage to the elastic ring, then the ring body is protected, but the device weight increases

Engineering Contradiction:
Improveelastic ring protectionVSAvoiddevice weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The braking function is extracted from the elastic ring system and implemented as a separate, dedicated braking element. This separation allows the piston collar to maintain its original, optimized dimensions without needing to be enlarged for protective purposes, thereby avoiding the weight penalty.

Inventive Principle:
Principle #2Taking out (Extraction)

4Object-generated harmful factors

If a pressure sensor and pressure spring system is used to transition from driving mode to braking mode, then recoil is reduced, but the device complexity increases

Engineering Contradiction:
Improverecoil reductionVSAvoidcontrol system complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The pressure sensor and pressure spring system automatically detects the piston's deceleration phase and triggers the braking element engagement without requiring external control signals or complex electronic systems. The system serves itself by using the inherent pressure changes during piston operation to activate the braking function at the appropriate moment.

Inventive Principle:
Principle #25Self-service

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

The solution effectively minimizes recoil energy by decelerating the tool early in its recoil movement, enhancing safety and reducing wear on the device components.

Implementation Method 1

a pressure spring wherein the pressure spring is connected to the pressure sensor such that the pressure spring is tensioned in the driving mode and at least partially relaxed in the braking mode

Methodology Applied
Scientific EffectElastic potential energy storage and release: Spring

Implementation Method 2

a braking element for reducing recoil energy in the working tool wherein the braking element is contacted with the pressure device

Methodology Applied
Scientific EffectKinetic energy dissipation through friction and deformation: Friction

Data Source

PatentEP4696461A1Setting tool with braking element
Publication Date: 2026.02.18 HILTI AG
  • EP4696461A1 patent drawingFigure 1
  • EP4696461A1 patent drawingFigure 2
  • EP4696461A1 patent drawingFigure 3a~3b

AI summary

The invention comprises a working tool for driving a fastening element into a substrate, comprising: - a working piston guide having a cavity, - a working piston, wherein the working piston is movably arranged in the working tool along a setting axis within the cavity of the working piston guide, - a pressure device for transitioning the working tool from a driving mode to a braking mode, comprising: - a pressure sensor, wherein the pressure sensor is in direct contact with the substrate in the driving mode, - a pressure spring, wherein the pressure spring is connected to the pressure sensor such that the pressure spring is tensioned in the driving mode and relaxed in the braking mode, so that the pressure sensor is movable in a setting direction of the working tool, - a braking element for reducing recoil energy in the working tool, wherein the braking element is contacted with the pressure device.