Snap Alignment Guard for Rivet-Free Nut Plate Ring Assembly

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Solution Overview

Problem

Current nut plate ring assemblies are time-intensive, labor-intensive, and costly to manufacture and assemble due to the need for multiple rivets and adhesives, which complicates the attachment and replacement of nut plates, especially in applications like missile casings where tolerance variations are significant.

Innovation Solution

A snap alignment guard with couplings and apertures that securely attach nut plates to a nut plate ring without rivets or adhesives, allowing for limited relative motion to accommodate tolerance variations and facilitate easy assembly and replacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If rivets and adhesives are used to attach nut plates to the ring, then the attachment is secure and durable, but the assembly process becomes time-intensive and labor-intensive

Engineering Contradiction:

Improveattachment securityVSAvoidassembly speed

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The alignment guard is divided into multiple modular components: the guard body with apertures for nut plate insertion, couplings for attachment to the ring, and a retention mechanism. This segmentation allows for rapid assembly where each component performs a specific function, eliminating the need for time-consuming riveting or adhesive application while maintaining secure attachment.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The alignment guard employs a dynamic retention mechanism that allows for quick release and reattachment of nut plates. The couplings enable the guard to be rapidly attached to and removed from the ring, facilitating fast assembly and replacement operations without permanent fastening methods like rivets or adhesives.

Inventive Principle:

Principle #15Dynamics

2Reliability

If multiple rivets are used to fix nut plates, then the nut plates are securely attached, but the replacement process becomes complex and time-consuming

Engineering Contradiction:

Improveattachment securityVSAvoidnut plate replaceability

Core Design Contradiction:

ReliabilityVSEase of repair

Solution Approach 1:

The alignment guard with its apertures and retention mechanism is pre-configured to facilitate easy nut plate insertion and removal. The couplings are pre-designed to engage with the ring structure, creating a ready-to-use assembly system that allows nut plates to be quickly replaced without requiring drilling out rivets or removing adhesives.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of permanently fixing nut plates with rivets that require drilling out for replacement, the invention inverts the approach by using a removable alignment guard that can be quickly detached and reattached. This allows nut plates to be replaced by simply removing and reattaching the guard rather than destroying previous fastenings.

Inventive Principle:

Principle #13The other way round (Inversion)

3Object-affected harmful factors

If a protective plastic cover with adhesive is used, then the nut plates are protected, but the assembly process takes hours for adhesive bonding and the cover must be removed for replacement

Engineering Contradiction:

ImproveprotectionVSAvoidassembly time

Core Design Contradiction:

Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The alignment guard acts as an intermediary component between the nut plates and the external environment, providing protection without requiring adhesive bonding. The guard's apertures allow nut plates to be secured while the couplings enable rapid attachment to the ring, eliminating the hours-long adhesive curing time associated with protective covers.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If rivets are used to attach nut plates, then the attachment is permanent and secure, but the process requires drilling 136 countersink holes for 68 nut plates

Engineering Contradiction:

Improveattachment permanenceVSAvoidnumber of holes and fasteners

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The alignment guard serves multiple functions simultaneously: it provides structural attachment to the ring via couplings, secures multiple nut plates through its apertures, and offers protection. This multi-functionality eliminates the need for individual rivets in each nut plate hole, reducing the total number of fastening operations from 136 rivets to a single guard assembly.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11060551B1Snap alignment guard for nut plate ring

Publication Date: 2021.07.13 LOCKHEED MARTIN CORP

AI summary

Disclosed herein is a snap alignment guard for a nut plate ring. The alignment guard includes a curved elongated body comprising an inner surface and an outer surface. The alignment guard further includes a plurality of couplings extending from the inner surface. Each of the plurality of couplings are configured to engage a nut plate ring to attach the alignment guard to the nut plate ring. The elongated body forms a plurality of apertures defined in the outer surface. Each of the plurality of apertures are configured to receive at least a portion of a nut plate to maintain a circumferential position of the nut plate relative to an inner surface of the nut plate ring.