One-Piece Drill Bit Cutting Head for Low-Friction Rebar Drilling

Solution Overview

Problem

Existing drill bits for masonry, concrete, brick, and rock drilling face challenges such as high friction leading to seizing and breaking, especially when encountering materials like rebar, which significantly slows down the drilling process.

Innovation Solution

A one-piece cutting head design featuring main cutting edges with rake and relief facets, side cutters, pockets, and friction reducing edges, which reduce friction and enhance drilling efficiency by minimizing heat buildup and wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional cutting edges are used for drilling into masonry with rebar, then drilling capability is maintained, but friction increases leading to seizing and breaking

Engineering Contradiction:

Improvedrill bit durabilityVSAvoidfriction-induced seizing

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The cutting head is divided into multiple functional zones: main cutting edges for primary material removal, side cutters for lateral cutting, and friction reducing cutting edges for minimizing contact friction. This segmentation allows each zone to perform its specific function optimally, preventing the friction-induced seizing that occurs with conventional unified cutting edges

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Friction reducing cutting edges act as intermediary elements between the main cutting edges and the drilled material. These edges specifically target and reduce frictional contact with rebar and other high-friction materials, preventing seizing before it can occur at the main cutting edges

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If conventional cutting edges without side cutters are used, then manufacturing is simpler, but drilling efficiency slows down the process

Engineering Contradiction:

Improvedrilling speedVSAvoidcutting head structure

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The cutting head is divided into multiple functional zones: main cutting edges for primary material removal, side cutters for lateral cutting, and friction reducing cutting edges for minimizing contact friction. This segmentation allows each zone to perform its specific function optimally, preventing the friction-induced seizing that occurs with conventional unified cutting edges

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cutting head design incorporates multiple cutting elements (main cutting edges, side cutters, and friction reducing edges) that collectively handle various drilling conditions. This multi-functional approach enables the single cutting head to efficiently drill through diverse materials including masonry, concrete, and rebar without requiring multiple specialized tools

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Duration of action of moving object

If conventional cutting edges are used, then the design is simpler, but heat buildup increases causing wear and reduced lifespan

Engineering Contradiction:

Improvedrill bit lifespanVSAvoidheat buildup at cutting edge

Core Design Contradiction:

Duration of action of moving objectVSTemperature

Solution Approach 1:

The cutting head is divided into multiple functional zones: main cutting edges for primary material removal, side cutters for lateral cutting, and friction reducing cutting edges for minimizing contact friction. This segmentation allows each zone to perform its specific function optimally, preventing the friction-induced seizing that occurs with conventional unified cutting edges

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The friction reducing cutting edges, while adding structural complexity, convert the harmful frictional heat into beneficial controlled material removal. By deliberately introducing additional cutting surfaces that manage friction, the design transforms potential heat-problematic contact into controlled cutting action that reduces overall heat buildup and extends drill bit lifespan

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS12551954B2One-piece cutting head for a drill bit

Publication Date: 2026.02.17 BLACK & DECKER CORP

AI summary

A one-piece cutting head for a drill bit includes a main cutting edge that extends between radial extremities of the cutting head. The main cutting edge is disposed between main rake surfaces and main relief surfaces. Each main rake surface includes one or more rake facets, and each main relief surface includes one or more relief facets. Adjacent rake facets and relief facets define a primary transverse edge therebetween that extends away from the main cutting edge. The cutting head further includes a plurality of side cutters that are transverse to the main cutting edge and that propagate from the primary transverse edge to a radial extremity of the cutting head. Each side cutter includes a side cutting edge between a side cutting rake facet and a side cutting relief facet.