Hollow Core Drill Bit Mandrel Stabilization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for drilling large diameter holes in concrete and other materials face challenges such as maintaining drill bit precision, stability, and efficiency, particularly with conventional systems that are bulky, heavy, and require significant effort to secure, leading to vibration, misalignment, and limited speed capabilities.
Innovation Solution
A system that uses a mandrel anchored in a pilot hole to stabilize a hollow, tubular core drill bit, allowing high-speed rotation with internal bearings for precise alignment and reduced vibration, and includes a releaseable latching mechanism to prevent falling debris during drilling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a conventional core drill rig is used to drill large diameter holes in concrete, then the drill bit can be stabilized, but the device becomes bulky, heavy, and requires bolting to the surface which complicates operation
Solution Approach 1:
The patent extracts the essential stabilization function from the complex bolted frame system and implements it through a simple pilot hole and mandrel assembly. The mandrel fits into a pre-drilled pilot hole, providing drill bit stabilization without requiring any bolting or complex frame structures to be attached to the concrete surface.
Solution Approach 2:
The drilling system is segmented into separate functional components: a pilot hole drilling stage, a mandrel insertion stage, and a core drilling stage. This segmentation allows each component to be optimized independently and eliminates the need for a single complex integrated system that would require bolting to the surface.
2Productivity
If the drill bit is rotated at high speed to improve productivity, then drilling efficiency increases, but the drill bit tends to walk sideways and vibrate laterally
Solution Approach 1:
The pilot hole is drilled first as a preliminary action to establish the precise center location and provide a guide for the mandrel. This preliminary positioning action enables subsequent high-speed core drilling to remain accurately centered without the drill bit walking sideways or vibrating laterally.
Solution Approach 2:
The mandrel acts as an intermediary element between the pilot hole and the core drill bit. It fits into the pilot hole and provides a stable reference that guides the core drill bit, enabling high-speed rotation while maintaining precise hole alignment and preventing lateral vibration.
3Stability of the object's composition
If a stabilizing frame is bolted to the concrete surface to prevent drill bit lifting, then drilling stability improves, but the operation becomes time-consuming and requires surface modification
Solution Approach 1:
The pilot hole is drilled as a preliminary action that simultaneously serves dual purposes: it provides a guide for the mandrel and creates the anchoring feature for stabilization. This eliminates the need for separate bolting operations and surface modifications required by conventional frame systems.
Solution Approach 2:
The pilot hole and mandrel assembly is self-contained and self-anchoring, requiring no external bolting or attachment to the concrete surface. The system stabilizes itself through the interference fit of the mandrel in the pilot hole, eliminating time-consuming frame attachment operations.
4Ease of operation
If vacuum suction is used to hold the drill frame to the concrete floor, then setup time is reduced, but sufficient suction force cannot be achieved when high torque is applied
Solution Approach 1:
The patent replaces the vacuum suction mechanical system with a purely mechanical interference fit system. The mandrel's tight fit in the pilot hole provides stabilization through friction and normal forces, eliminating the need for vacuum suction mechanisms and their associated reliability issues under high torque conditions.
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
Enables precise, high-speed drilling of large diameter holes with reduced torque and improved stability, allowing for efficient cutting and minimizing the risk of damage or injury from falling debris.
Implementation Method 1
at least one bearing mounted to the driven end of the annular hollow drive shaft and residing in rotational and longitudinal sliding surface contact with the mandrel
Data Source
AI summary
An apparatus for drilling holes in a substrate wherein a mandrel is anchored to the substrate. A hollow drill bit rotates about the mandrel via a drive motor and is a guided along a length of the mandrel.