Lock Washer with Spring-Bent Tabs and Etched Thickness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lock washers face issues with corrosion due to sharp edges that penetrate protective coatings, difficulty in loosening and reusing, especially with open-end wrenches, and structural weaknesses that lead to permanent deformation.
Innovation Solution
A lock washer design featuring a planar washer body with radially outward lock tabs that are spring-bent and etched to a lesser thickness, allowing for easy engagement and disengagement without requiring excessive force, and incorporating wings for socket compatibility, preventing the washer from falling into bolt threads and allowing for reuse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lock washers include sharp edges or points to dig in and lock the nut, then the locking function is improved, but the protective coating on the nut and surface is penetrated causing corrosion
Solution Approach 1:
The lock tabs are provided with a curved locking surface instead of a sharp edge, creating a localized contact area that distributes pressure evenly. This curved surface engages the flat of the nut without concentrating stress at a single point, thereby preventing penetration of protective coatings while maintaining effective locking.
2Reliability
If multiple lock tabs are provided to engage all flats of the nut, then the locking function is improved, but the force required to loosen the nut becomes excessively high (65-80 lbs)
Solution Approach 1:
Instead of providing lock tabs for every flat of the nut, the invention extracts the essential locking function by providing only two lock tabs positioned to engage opposite flats of the nut. This reduction maintains sufficient locking reliability while dramatically reducing the force required to loosen the nut, making it compatible with standard wrenches.
3Reliability
If lock tabs are displaced in the plane of the washer body, then the locking function is achieved, but the tabs cannot be easily depressed with standard wrenches preventing nut loosening
Solution Approach 1:
The lock tabs are displaced out of the plane of the washer body in the radial direction, creating a three-dimensional structure. This dimensional change allows the tabs to engage the flats of the nut effectively while permitting standard wrenches to apply loosening force by depressing the tabs radially inward, solving both locking and loosening requirements.
4Ease of operation
If the washer body is made thin to allow easy tab deformation, then the loosening operation is easier, but the washer may fall into the pitch of the bolt thread
Solution Approach 1:
The washer body is provided with a selected thickness that is no less than the bolt pitch thread, ensuring the body is thick enough to prevent falling into the thread pitch. Meanwhile, the lock tabs are locally thinned or designed with appropriate geometry to allow easy deformation during loosening operations, separating the structural support function from the locking mechanism function.
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 facilitates easy loosening and reusability of lock washers with standard tools, prevents corrosion by avoiding sharp edges, and maintains structural integrity to prevent deformation during use and removal.
Implementation Method 1
each of the tabs is displaced by a spring bend to one side of the plane of the body. The washer body is etched to a selected lesser thickness in the area of the spring bend to provide a selected spring force when the tab is pushed down to the plane of the body
Data Source
AI summary
A lock washer includes a planar washer body formed of a sheet of resilient metal having a selected thickness no less than the pitch thread of the bolt with which it is to be used. First and second lock tabs integral with the body extend radially outward of the central aperture, wherein each of the tabs has a radially inward facing, straight, free edge transverse to a radius of the body, and each of the tabs is displaced by a spring bend to one side of the plane of the body. The washer body is etched to a selected lesser thickness in the area of the spring bend to provide a selected spring force when the tab is pushed down to the plane of the body.