Expandable Drill Bit Torsion Spring Blade Mechanism
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Solution Overview
Problem
Existing rotary drilling devices are ineffective in expanding the diameter of holes, particularly when high-speed rotation is not feasible due to debris buildup or subsurface conditions, and they are prone to blade wear and breakage.
Innovation Solution
An expandable diameter drill bit with torsion springs that bias blades outward, allowing for automatic expansion of the hole diameter and enhanced cutting efficiency through serrated blades coated with hard materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If blades are urged outwardly by centrifugal force, then hole diameter can be expanded, but high speed rotation is required which may not be possible in some subsurface conditions
Solution Approach 1:
The patent replaces the centrifugal force mechanism with a torsion spring mechanism. Instead of relying on high-speed rotation to generate centrifugal force to expand blades outward, the invention uses pre-loaded torsion springs to provide the expanding force directly, eliminating the requirement for high rotation speeds while achieving the same hole expansion effect
Solution Approach 2:
The torsion springs are pre-loaded before the drilling operation begins, storing mechanical energy in advance. This preliminary action allows the blades to be forced outward immediately upon contact with the wellbore wall, without waiting for high-speed rotation to generate sufficient centrifugal force, thus enabling expansion at lower rotation speeds
2Productivity
If blades operate at high speed, then drilling efficiency is improved, but blades wear out, break, or fail more quickly
Solution Approach 1:
The patent implements a dynamic blade system where blades can pivot between a retracted position (reducing stress and wear) and an extended cutting position (maximizing cutting efficiency). The torsion springs allow blades to flex and adapt to varying subsurface conditions, reducing the likelihood of catastrophic failure while maintaining high productivity during actual cutting operations
3Device complexity
If a drill bit with fixed diameter is used, then the structure is simple, but the hole diameter cannot be increased without replacing the drill bit
Solution Approach 1:
The drill bit is segmented into a modular structure with multiple independent blades that can be positioned at different radial distances from the center. Each blade is independently mounted on a pivot shaft and can be extended or retracted, allowing the overall cutting diameter to be adjusted without changing the basic drill bit structure, thus providing versatility while maintaining relative simplicity
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 drill bit efficiently enlarges hole diameters with reduced blade breakage and improved cutting performance through the mechanical energy stored in torsion springs and the use of hard-coated serrated blades, effectively handling subsurface compositions and debris.
Implementation Method 1
A torsion spring having a helical coil, a first blade leg, and a second body leg. The blade bolt passes through the bolt receiving holes and the pivot shaft and is secured into position with a blade bolt set screw. The first blade leg is coupled to the cutting blade with a spring retainer bolt, the second body leg is coupled to the drill head body, and the torsion spring biases the blade outwardly from the drill head body.
Data Source
AI summary
An expandable diameter drill bit includes a cutting blade having receiving and contacting ends, the receiving end having a pivot shaft and the contacting end having a tip. A drill bit includes a drill head body having an upper attachment portion and a lower body portion, the lower body portion defining a blade opening for receiving the receiving end of the cutting blade and a bolt receiving hole on opposing sides transverse the blade opening. The drill bit includes a torsion spring, a first blade leg, and a second body leg. The blade bolt passes through the bolt receiving holes and the pivot shaft and secured with a set screw. The first blade leg is coupled to the cutting blade with a spring retainer bolt, the second body leg is coupled to the drill head body, and the torsion spring biases the blade outwardly from the drill head body.