Snap Hook Shell Teeth Guide Spring Recess
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional snap hook apparatuses face difficulties in precise assembly due to narrow slits that make it hard to position springs correctly, and the shells can break with repeated use.
Innovation Solution
The snap hook apparatus features a shell with teeth on an annular rib, eliminating the need for a slit by guiding the spring's end into a recess defined by the teeth's slope and vertical facet, and a robust design that prevents shell breakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a narrow slit is used to position the spring end, then the spring can be positioned in the shell, but it is difficult to precisely position the spring and the shell may break with repeated use
Solution Approach 1:
The shell is divided into multiple teeth (first tooth, second tooth, third tooth, fourth tooth) that collectively form a recess structure. This segmentation allows the spring end to be positioned by multiple reference points rather than a single narrow slit, improving positioning precision while distributing stress across multiple structural elements to prevent shell breakage.
Solution Approach 2:
The recess formed by the teeth acts as an intermediary structure between the spring end and the shell wall. Instead of directly inserting the spring end into a narrow slit that stresses the shell, the recess provides a gradual transition zone that guides the spring end into position while reducing stress concentration on the shell material.
2Ease of manufacture
If a narrow slit is used for spring insertion, then the spring can be inserted into the shell, but the assembly process becomes difficult and time-consuming
Solution Approach 1:
The recess is pre-formed by the teeth structure on the shell before spring insertion. This preliminary structural preparation provides clear guidance for spring end placement, eliminating the need for precise manual alignment during assembly. The spring end can be directly inserted into the pre-formed recess without requiring complex positioning operations.
Solution Approach 2:
The recess structure formed by the teeth automatically guides and positions the spring end during insertion. The geometry of the recess (formed by the sloping surfaces of adjacent teeth) self-aligns the spring end without requiring external positioning tools or complex assembly procedures, making the assembly process intuitive and rapid.
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
This design simplifies assembly by ensuring easy and precise spring positioning and enhances the shell's durability by eliminating the risk of breakage during repeated use.
Implementation Method 1
a torsion spring having a first end inserted in a bore made in the bolt and a second end inserted in a recess defined by and between two adjacent ones of the teeth of the shell
Implementation Method 2
an elastic strip inserted in the shell
Data Source
AI summary
A snap hook apparatus includes a shell, a bolt, a hook, two pins, a torsion spring and an elastic strip. The shell includes an annular rib formed on an internal side and teeth formed on the annular rib. The bolt includes two lugs, an annular shoulder, and a bore near the annular shoulder. The hook includes a catch at a first end and an aperture in a second end. The first pin is inserted in the first lug and used for engagement with the catch of the hook. The second pin is inserted in the second lug and the second end of the hook. The torsion spring includes a first end inserted in the bore of the bolt and a second end inserted in a recess defined between two adjacent ones of the teeth of the shell. The compression spring and the elastic strip are inserted in the shell.