Rotary Drill Bit Engagement Features for HDD Pullback Attachment
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Solution Overview
Problem
Horizontal directional drilling operations are time-consuming and require additional tooling due to the need to remove the rotary drill bit from the drill string for product installation, which complicates the pullback process.
Innovation Solution
A pullback device is designed to attach to the rotary drill bit without disassembling it from the drill string, utilizing a coupler and engagement features to facilitate the attachment of products, allowing for the drill bit to remain in place while pulling back the product through the drilled hole.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the rotary drill bit is removed from the drill string to attach the pullback device, then the pullback device can be properly attached to install the product, but the operation becomes time-consuming and requires additional tooling
Solution Approach 1:
The drill bit is pre-configured with engagement features (axial bores, radial bores, threads) during manufacturing, so that when the drilling operation is complete, the pullback device can be quickly attached without removing the drill bit. The engagement features are prepared in advance to receive the pullback device's attachment components.
Solution Approach 2:
The drill bit is designed with dual functionality: it serves both as the drilling tool (with cutting portions and vanes) and as the attachment interface for the pullback device (with engagement features). This multi-functionality eliminates the need to remove the drill bit, as it can directly accept the pullback device for product installation.
2Ease of operation
If the rotary drill bit is removed from the drill string, then the pullback device can be attached, but the device complexity increases due to additional tooling requirements
Solution Approach 1:
The drill bit integrates both drilling functionality (cutting portions, vanes) and attachment functionality (engagement features with axial and radial bores, threads) into a single component. This eliminates the need for separate removal tooling and simplifies the overall system by making the drill bit universal for both operations.
Solution Approach 2:
The invention merges the drill bit and the attachment interface into a single integrated component. The engagement features (axial bores, radial bores, threads) are built into the drill bit itself, combining the drilling tool and the mounting interface, thereby reducing device complexity and eliminating the need for additional tooling.
3Productivity
If the rotary drill bit remains attached to the drill string, then time and tooling requirements are reduced, but the pullback device must be designed to attach without removal
Solution Approach 1:
The engagement features (axial bores, radial bores, threads) are pre-configured in the drill bit during manufacturing, enabling the pullback device to attach directly without drill bit removal. This preliminary preparation of attachment interfaces maintains high productivity while managing complexity through standardization.
Solution Approach 2:
The drill bit is designed as a multi-functional component that serves both as the drilling tool and as the attachment interface for the pullback device. The engagement features integrate both functions, improving productivity by eliminating removal steps while concentrating complexity into a single universal component.
Data Source
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AI summary
A rotary drill bitb (200A) for use with a horizontal directional drill string. A coupler (206) at a proximal axial end is configured to attach the rotary drill bit to a drill head at a distal end of the drill string. A cutting portion at a distal axial end is provided with a plurality of vanes (204) with respective cutters that operate to cut a hole in earth when the rotary drill bit is rotated about a central axis. The plurality of vanes project radially outwardly from a surface of the cutting portion such that the surface forms respective troughs (214) circumferentially interspersed with the plurality of vanes. A plurality of engagement features (212a) is positioned axially within the cutting portion and radially inward of an outer cutting diameter to facilitate attachment of a product pullback device (1000) between the plurality of vanes without removing the rotary drill bit, or any portion thereof, from the drill head.