Fastener with Deformable Ridges for Non-Threaded Bore Press-Fit
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Solution Overview
Problem
Existing fasteners are not effectively usable for non-threaded bores, as they lack the necessary features to provide a secure and frictional grip without causing excessive friction or manufacturing complexity.
Innovation Solution
A fastener comprising a first member with an externally threaded shank and an axially extending projection, along with a second member that is at least partly deformable and features longitudinally extending outer ridges, allowing it to be press-fitted into non-threaded bores, with the ridges providing a stable contact surface while being easily insertable and manufacturable.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fastener uses a threaded shank design for traditional threaded bores, then it provides secure fastening, but it cannot be used for non-threaded bores
Solution Approach 1:
The fastener is divided into two separate members: a first member with the threaded shank for secure fastening, and a second member with ridges for insertion into non-threaded bores. This segmentation allows each member to specialize in its function, enabling the fastener to work with non-threaded bores while maintaining secure attachment capability
Solution Approach 2:
The second member is inserted into the bore, and the first member is then inserted into the second member, creating a nested structure. The threaded shank of the first member engages with the ridges of the second member, allowing the combination to function in non-threaded bores while maintaining secure fastening through the threaded engagement
2Reliability
If the second member has a large contact surface with the non-threaded bore, then it provides secure grip, but it causes excessive friction making insertion difficult
Solution Approach 1:
The contact surface of the second member is segmented into multiple discrete ridges rather than a continuous surface. This segmentation reduces the total contact area and friction during insertion, while still providing sufficient grip strength once positioned in the bore
Solution Approach 2:
The ridges are designed with specific local characteristics - they have enhanced width or depth at certain positions to provide localized grip points. This allows the contact surface to be optimized for both low friction during insertion and high grip strength during 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 fastener effectively secures objects to non-threaded bores with minimal friction, ensuring stable positioning and easy insertion, and can be manufactured efficiently, making it suitable for various applications such as securing inflatable curtains in vehicles.
Implementation Method 1
a second at least partly deformable member attached to the axially extending projection
Implementation Method 2
the longitudinally extending outer ridges of the second member make the present fastener useable for a non-threaded bore... the ridges may provide for an appropriate contact surface with the non-threaded bore
Data Source
AI summary
The present invention relates to a fastener (10) for a non-threaded bore (50), which fastener comprises: a first member (12) with a head (18), an externally threaded shank (20) extending from the head, and an axially extending projection (22) at the opposite end (24) of the shank compared to the head; and a second at least partly deformable member (14) attached to the axially extending projection, wherein the second member comprises a plurality of longitudinally extending outer ridges (40a-d). The present invention also relates to a method of mounting a first object (46) to a second object (48) using such a fastener, and to a method of manufacturing a fastener (10).