Electric Crimp Tool Planetary Roller Screw Mechanism

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Solution Overview

Problem

Current crimp tools for plastic applications, particularly those using battery-powered designs, face challenges such as excessive user effort, tool size, weight, and inefficiency in delivering the required force for PEX crimping, leading to operator fatigue and suboptimal performance.

Innovation Solution

A handheld crimp tool with a planetary roller screw assembly and a modified toggle mechanism, featuring a jaw assembly with a cam linkage and lever system, which allows for efficient force transmission and reduced user effort, enabling one-handed operation and minimizing tool size and weight while ensuring proper alignment and avoiding partial crimps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual tools with toggle mechanism are used for plastic crimping, then the tool can achieve mechanical advantage, but operator discomfort and exhaustion occur when many crimps must be made

Engineering Contradiction:

Improveoperator comfortVSAvoidnumber of crimps per operator

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The patent replaces the manual toggle mechanism with an electric motor-driven planetary roller screw assembly. The motor provides automated actuation of the jaw assembly, eliminating the need for operator to manually operate the toggle mechanism while maintaining the mechanical advantage through the planetary roller screw system. This substitution directly addresses operator fatigue while preserving crimping effectiveness.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The powered crimp tool performs the crimping action automatically through the electric motor and planetary roller screw assembly, which self-generate the necessary force without requiring continuous manual intervention. The system serves itself by converting electrical energy to mechanical motion, allowing the operator to simply position the tool rather than continuously manipulate mechanical linkages during the crimping process.

Inventive Principle:

Principle #25Self-service

2Force

If battery powered hydraulic tools are used for metal systems, then high forces can be attained, but the tools are not suitable for plastic crimping applications

Engineering Contradiction:

Improvecrimping forceVSAvoidapplicability to plastic systems

Core Design Contradiction:

ForceVSAdaptability or versatility

Solution Approach 1:

The patent changes the fundamental operating parameters from hydraulic (fluid-based) to electric-mechanical (motor and screw assembly). This parameter change allows the tool to deliver appropriate force levels for plastic crimping without the excessive force and complexity of hydraulic systems. The planetary roller screw assembly provides controlled, high-force output suitable for plastic materials while maintaining tool size and weight appropriate for versatility in plastic piping applications.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent substitutes the hydraulic system with an electric motor-driven mechanical system using a planetary roller screw assembly. This replacement makes the tool specifically adapted for plastic crimping applications by providing precisely controlled force delivery that matches the requirements of plastic materials, unlike hydraulic systems designed for metal applications.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Force

If conventional screw mechanisms are used in battery powered crimp tools, then the tools can apply force to toggle mechanism, but the tools become larger and heavier

Engineering Contradiction:

Improveforce application capabilityVSAvoidtool weight

Core Design Contradiction:

ForceVSWeight of moving object

Solution Approach 1:

The patent employs a dynamic planetary roller screw assembly that integrates the screw mechanism within a compact planetary gear structure. This dynamic configuration allows the force-generating components to be nested within each other, significantly reducing the overall tool weight and size while maintaining the capability to apply high crimping forces through the jaw assembly.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The planetary roller screw assembly is nested within the tool housing in a compact arrangement where the screw mechanism, planetary gears, and jaw assembly are integrated in a space-efficient manner. This nesting principle allows the tool to maintain high force application capability while minimizing weight and size, making it suitable for handheld operation in confined spaces.

Inventive Principle:

Principle #7Nested doll (Nesting)

4Productivity

If conventional crimp tools are used, then crimping can be performed, but partial crimps occur and productivity is reduced

Engineering Contradiction:

Improvecrimp completion rateVSAvoidcrimp quality consistency

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent incorporates a sensor system that provides feedback on the crimping process status. The sensor detects when the jaw assembly has completed the full crimping stroke and verifies proper crimp formation. This feedback mechanism allows the control system to ensure complete crimps are achieved, preventing partial crimps and the associated productivity losses from rework.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The powered actuation system performs preliminary positioning of the jaw assembly to ensure proper alignment with the fitting before the crimping force is applied. This preliminary action, controlled by the electric motor and planetary roller screw assembly, prevents misalignment that could lead to partial crimps, ensuring consistent crimp quality and maintaining high productivity.

Inventive Principle:

Principle #10Preliminary action

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 provides a lightweight, compact, and cost-effective crimp tool that reduces user fatigue, increases productivity, and effectively delivers the necessary force with minimal wear and heat generation, ensuring complete crimps and improved usability in confined spaces.

Implementation Method 1

Methodology Applied

Scientific EffectMechanical Advantage: Mechanical Advantage

Implementation Method 2

The jaw assembly also comprises a cam linkage member pivotally coupled to the first jaw by a cam pivot pin. The jaw assembly also comprises a lever coupled to the first jaw. The lever and the cam linkage member are positioned and configured such that the first jaw and the second jaw can be positioned toward the open position from the closed position by manually moving the lever so as to contact the cam linkage member and pivot the cam linkage member about the cam pivot pin.

Methodology Applied

Scientific EffectCam mechanism: Cam

Data Source

PatentUS11707879B2Electrically powered crimp tool

Publication Date: 2023.07.25 RIDGE TOOL CO

AI summary

Electrically powered crimp tools are described. Also described are methods of operating the tools and methods of crimping. The tools include a housing, an electric motor, a roller screw assembly, and a jaw assembly. In particular versions of the tools the jaw assembly includes a cam linkage member that is manually displaced by a user to more easily open the jaws after performing a crimp.