Blind Fastener Installation Tool With Clutched Bolt-Nut Rotation

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Solution Overview

Problem

Existing blind fasteners face challenges in controlling the rotation of both the bolt and nut, achieving a flush finished product, maximizing installation speed, and reducing costs, while also adapting to variations in grip length without compromising joint strength. Additionally, typical fasteners lack a torque control feature, which can lead to defective installations.

Innovation Solution

A tool for installing blind fasteners is developed, featuring a base, collet, socket assembly, drive body, and mode clutch. The tool includes a collet that selectively engages the nut, a socket assembly with rollers to rotate the bolt, a drive body to rotate the socket housing, and a mode clutch to couple the socket housing with the collet for common rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If rotation of the bolt and nut is controlled during installation, then the flush finish and joint strength are improved, but the device complexity increases due to the need for mode clutch and roller mechanisms

Engineering Contradiction:
Improveflush finishVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The mode clutch transitions between engaged and disengaged states dynamically during installation. When engaged, it couples the socket housing with the collet for common rotation to achieve flush finish. When disengaged, it allows independent rotation control. This dynamic state change enables precise rotation control without permanently complex mechanisms.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rollers act as intermediaries between the socket housing and the bolt. They transmit rotational motion from the socket housing to the bolt while allowing for controlled slip and rotation differential. This intermediary mechanism enables precise rotation control without direct rigid coupling.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the installation process is simplified to increase speed, then the productivity improves, but the control over bolt and nut rotation is lost

Engineering Contradiction:
Improveinstallation speedVSAvoidrotation control
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The fastener is pre-assembled with the bolt and nut in specific configurations before installation. The mode clutch is pre-configured to engage at specific rotation points. This preliminary preparation allows the installation process to proceed quickly without sacrificing rotation control, as the control mechanisms are already positioned and configured.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The mode clutch and roller mechanisms are designed to automatically engage and disengage based on the installation process itself. The system self-regulates the rotation control without requiring external intervention or complex control systems, maintaining precision while enabling fast installation.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If the fastener design is simplified to reduce cost, then the loss of substance decreases, but the adaptability to grip length variations is reduced

Engineering Contradiction:
Improveadaptability to grip lengthVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The mode clutch provides dynamic adaptability to different grip lengths by allowing the installation process to adjust the rotation and engagement phases based on the specific fastener configuration. This enables a single tool design to handle multiple grip length variations without requiring multiple specialized tools.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The socket assembly with rollers and mode clutch serves multiple functions: it controls rotation, accommodates grip length variations, and ensures proper fastener installation. This multi-functionality allows a single device to handle diverse fastening requirements without increasing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Reliability

If torque control feature is added to prevent excessive torque, then the reliability of installation improves, but the device complexity increases

Engineering Contradiction:
Improveinstallation reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The mode clutch and roller mechanism provide inherent feedback during the installation process. The rollers naturally slip and disengage when excessive torque is applied, providing automatic feedback that prevents over-torquing. This feedback mechanism is built into the mechanical design rather than requiring separate electronic or mechanical torque control systems.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4015151B1Two-piece blind fastener and installation tool
Publication Date: 2025.06.18 SPS TECHNOLOGIES LLC
  • EP4015151B1 patent drawingFigure 1~2
  • EP4015151B1 patent drawingFigure 3~4
  • EP4015151B1 patent drawingFigure 5~6

AI summary

A tool (510) for installing a blind fastener (10) including a bolt (14) and a nut (18) includes a base (534), collet (710), socket assembly (714), drive body (718), and mode clutch. The collet is coupled to the base and disposed about an axis (530). The collet can selectively engage a portion of the nut. The socket assembly includes a socket housing (610) and a plurality of rollers (614). The socket housing is rotatable relative to the collet and defines a bore disposed about the axis. The rollers are spaced circumferentially about the axis. A surface of each roller can engage a cylindrical portion of the bolt within the bore to rotate the bolt about the axis. The drive body is coupled to the socket housing and configured to rotate the socket housing about the axis relative to the base. The mode clutch is configured to selectively couple the socket housing with the collet for common rotation about the axis.