Quick-Release Shank With Polygonal Hole And Expandable Locking Member
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Solution Overview
Problem
Conventional quick-release devices for screwdriver bits require multiple steel balls for positioning, leading to increased processing complexity and cost due to the need for a thick ring for structural strength, resulting in wasted material and limited operational space.
Innovation Solution
A shank with a polygonal hole and an expandable locking member, where the locking member is non-rotatable and engages with a protrusion to securely hold the bit in place, eliminating the need for steel balls and allowing for a thinner shank design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple steel balls are radially disposed in the ring for positioning bits, then the bit positioning function is improved, but the processing complexity and manufacturing cost increase due to the need for a thick ring structure
Solution Approach 1:
The patent removes the steel balls from the ring structure entirely. Instead of having multiple steel balls radially disposed in the ring for positioning, the invention uses a simplified ring without balls, and positions bits using the polygonal hole and slot mechanism in the shank alone.
Solution Approach 2:
The patent combines the positioning function previously performed by separate steel balls into the integrated shank structure. The polygonal hole and slot are formed directly in the shank, merging the positioning mechanism with the main body, thereby eliminating the need for a complex processed ring with steel balls.
2Strength
If the ring is made thicker to ensure structural strength after processing, then the structural strength is improved, but the metal material is wasted and the operating space is reduced
Solution Approach 1:
The patent eliminates the need for a thick-walled ring by removing the steel ball positioning mechanism. The shank is designed with a thinner wall thickness because it uses an integrated polygonal hole and slot structure that does not require the same structural reinforcement as a ring with radially disposed steel balls.
3Strength
If the ring is made thicker to ensure structural strength, then the structural strength is improved, but the operating space is limited and operation becomes inconvenient
Solution Approach 1:
By removing the steel ball positioning mechanism and the associated thick ring structure, the patent creates more internal space in the shank. This allows for better bit insertion and removal operations, improving ease of operation while maintaining sufficient structural strength through the integrated polygonal hole and slot design.
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 solution reduces manufacturing costs and operational complexity by eliminating the need for steel balls, providing a more efficient and compact quick-release mechanism for screwdriver bits.
Implementation Method 1
An expandable limit element is received in the annular groove, wherein the limit element has an outer diameter slightly smaller than a diameter of the annular groove. A sleeve is movably sleeved on the first end of the shank. The sleeve has at least one protrusion inwardly extending therefrom, wherein the at least one protrusion is engaged into the at least one slot to prevent the sleeve from being rotated relative to the hollow stub and the at least one protrusion abuts against the limit element when removing the bit form the polygonal hole.
Data Source
AI summary
A quick-release device for screwdriver bit includes a shank having a polygonal hole longitudinally defined in one end thereof and adapted for partially receiving a bit. At least one slot is longitudinally defined in the shank. An annular groove is defined in an inner periphery of the polygonal hole and communicates with the at least one slot, wherein the annular groove is formed with a tapered section toward the first end of the shank. An expandable limit element is received in the annular groove. A sleeve is movably sleeved on the shank. The sleeve has at least one protrusion inwardly extending therefrom and engaged into the at least one slot and abutting against the limit element when removing the bit form the polygonal hole. A stopper is secured on one end of the shank for preventing the sleeve from removing from the shank.