Rotary Drill Bit Engagement Features for Pullback Without Disassembly
Find Innovative SolutionsGenerate Solutions
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 attaching pullback devices, which complicates the installation of products like cables or pipes in drilled holes.
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 secure the device and allow for the installation of products without removing the drill bit, facilitating easier and more efficient pullback operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rotary drill bit is removed from the drill string to attach a pullback device, then the pullback device can be securely attached, but the operation time increases and additional tooling is required
Solution Approach 1:
The drill bit is designed with engagement features (such as keys, grooves, or protrusions) pre-formed during manufacturing, allowing the pullback device to be attached directly without removal. This preliminary preparation of attachment interfaces eliminates the time-consuming removal and reattachment process while maintaining secure connection.
Solution Approach 2:
The pullback device is designed to nest around or within the drill bit structure, with the drill bit serving as the inner component and the pullback device as the outer component. This nested configuration allows the pullback device to be attached to the drill bit while the drill bit remains in the drill string, eliminating the need for drill bit removal.
2Reliability
If the rotary drill bit is removed from the drill string to attach a pullback device, then the pullback device can be securely attached, but the device complexity increases due to additional tooling requirements
Solution Approach 1:
The drill bit is designed with multi-functional engagement features that serve both drilling operations and pullback device attachment. The same structural elements (such as the drill bit body, flanges, or integrated attachment points) that provide drilling functionality also provide secure attachment points for the pullback device, eliminating the need for specialized tooling.
Solution Approach 2:
The attachment interface for the pullback device is merged with the drill bit structure itself, rather than being a separate component. The engagement features are integrated into the drill bit design, combining the drilling function and attachment function into a unified structure, thereby reducing overall system complexity.
3Productivity
If engagement features are positioned within the cutting portion of the drill bit, then the pullback device can be attached without removing the drill bit, but the engagement features must be precisely located to avoid interfering with cutting operation
Solution Approach 1:
The engagement features are positioned in specific localized areas of the drill bit where they do not interfere with the cutting operation. For example, engagement features may be located on the non-cutting portions of the drill bit body, on the flanges, or in recesses that are axially offset from the cutting elements. This localized positioning allows both functions to coexist without interference.
Solution Approach 2:
The engagement features are positioned in the axial dimension rather than interfering with the radial cutting elements. By placing engagement features on the drill bit body in the axial direction (such as on the face of the drill bit or on the shaft portion), the design separates the attachment function from the cutting function in different spatial dimensions, avoiding interference.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A rotary drill bit for use with a horizontal directional drill string. A coupler 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 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 circumferentially interspersed with the plurality of vanes. A plurality of engagement features is positioned axially within the cutting portion and radially inward of an outer cutting diameter to facilitate attachment of a product pullback device between the plurality of vanes without removing the rotary drill bit, or any portion thereof, from the drill head.