Blind Rivet-Nut Structure for Self-Centering Screw Engagement
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Solution Overview
Problem
Existing blind rivet-nuts face issues with tilting and jamming during screwing operations due to the need for precise positioning and centering of threaded elements, which complicates large-batch production and securement.
Innovation Solution
A blind rivet-nut design featuring a threadless shaft portion between the clamping and threaded portions, allowing for self-rolling or self-tapping screws or bolts to form a positive-locking thread, preventing tilting and jamming while ensuring self-centering during screwing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a threaded portion is provided in the hollow shaft for receiving a threaded element, then the blind rivet-nut can be securely connected to provide a securing thread, but the threaded element requires precise straight positioning and centering to prevent tilting and jamming during screwing
Solution Approach 1:
The hollow shaft is segmented into three distinct portions: a clamping portion, a threadless shaft portion, and a threaded portion. The threadless shaft portion acts as an intermediate segment that receives the threaded element before it engages with the threaded portion, providing guidance and preventing tilting during the screwing operation.
Solution Approach 2:
The threadless shaft portion serves as an intermediary element between the clamping portion and the threaded portion. It receives the threaded element (screw or bolt) and guides it into proper alignment, preventing direct contact between the threaded element and the threaded portion that would cause tilting or jamming.
2Reliability
If precise positioning and centering of the threaded element is required, then securement is achieved, but the screwing operation becomes complex and time-consuming in large-batch production
Solution Approach 1:
The threadless shaft portion enables the threaded element to self-center and self-align during insertion. The geometry of the threadless shaft portion automatically guides the threaded element into the correct position, eliminating the need for external positioning devices or complex alignment procedures that would reduce productivity.
3Ease of operation
If the threaded element is placed obliquely on the thread, then insertion is easier, but the threaded element becomes jammed during the screwing-in operation
Solution Approach 1:
The threadless shaft portion performs a preliminary receiving function, capturing the threaded element in a neutral, unthreaded space first. This preliminary action allows the threaded element to be inserted without immediate engagement with the threads, preventing oblique placement and subsequent jamming during the screwing operation.
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 design enhances securement by preventing tilting and jamming, facilitating easier and more precise screwing operations, particularly in large-batch production, and ensures secure retention of components without deformation of the threadless shaft portion.
Implementation Method 1
The clamping portion is intended, during a setting operation of the blind rivet-nut on the carrier, to become deformed in a bead-like manner in order thus to clamp the carrier between the bead-like deformation of the clamping portion and the setting head
Implementation Method 2
an additional threadless shaft portion is formed in the hollow shaft between the clamping portion and the threaded portion. This threadless shaft portion is suitable and constructed for receiving a thread self-rolling or thread self-tapping screw or bolt in a positive-locking manner therein when the screw/bolt is screwed into the shaft portion
Data Source
AI summary
A blind rivet-nut having an annular-flange-like setting head and a hollow shaft for securing a blind rivet-nut in an opening of a carrier. The hollow shaft has a free end having a threaded portion for receiving a threaded element of a tensioning tool. A clamping portion adjacent to the setting head forms a bead-like deformation when the tensioning tool is used to clamp the carrier between the bead-like deformation and the setting head. A threadless shaft portion is formed between the clamping portion and the threaded portion. The threadless shaft portion is threaded by a thread self-rolling or thread self-tapping fastener. The fastener is received in a positive-locking manner when the fastener is screwed into the thread formed on the previously threadless shaft portion. A method is also disclosed for securing a component to a carrier by a blind rivet-nut.