Quick Release DTH Drill Bit Assembly Retaining Sleeve

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional down-the-hole percussive drill coupling arrangements face challenges with drill bit detachment, requiring complex tooling for removal and replacement, and accelerated wear leading to component damage and inefficient maintenance.

Innovation Solution

A drive coupling system with a retaining sleeve and retaining formations that allow axial decoupling of the drill bit from the drive sub without disassembling the assembly, isolating the coupling components from torque and drilling forces, enabling quick and convenient replacement of drill bits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional retaining ring arrangements are used to retain the drill bit, then the drill bit can be retained at the assembly, but it becomes very difficult to remove the drive sub and break-open the assembly without dedicated tooling

Engineering Contradiction:

Improvedrill bit retentionVSAvoidremoval and installation of replacement drill bit

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The coupling arrangement is segmented into modular components: a drive sub, a drill bit, and a retaining sleeve that can be independently assembled and disassembled. The retaining sleeve acts as an intermediate component that can be removed separately from the drive sub, allowing the drill bit to be changed without breaking open the entire assembly. This segmentation enables maintenance personnel to access and replace the drill bit quickly by simply removing the retaining sleeve.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The retaining sleeve serves as an intermediary component between the drive sub and the drill bit. It provides the retention function while being easily removable, thus mediating between the need for secure retention during operation and the need for easy removal during maintenance. The sleeve can be quickly detached to allow drill bit replacement without affecting the drive sub or requiring specialized tooling.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If retaining sleeves are rotatably locked at the drive sub to retain detached bit heads, then detached bit heads can be retained at the assembly, but the worn components cannot be replaced without breaking-open the drive sub

Engineering Contradiction:

Improvedetached bit head retentionVSAvoidreplacement of worn components

Core Design Contradiction:

ReliabilityVSEase of repair

Solution Approach 1:

The coupling system is divided into replaceable segments, where the retaining sleeve is a separate component from the drive sub. When the retaining sleeve becomes worn, it can be removed and replaced independently by simply detaching the sleeve from the drive sub, without needing to break open or disassemble the drive sub itself. This segmentation makes maintenance straightforward and reduces downtime.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The retaining sleeve is designed as a recoverable component that can be removed, inspected, and replaced when worn. Instead of discarding the entire drive sub assembly, only the worn retaining sleeve needs to be replaced. The sleeve can be recovered from the assembly, examined for wear, and swapped out for a new one, maintaining the valuable drive sub for continued use.

Inventive Principle:

Principle #34Discarding and recovering

3Reliability

If conventional coupling arrangements are used, then the drill bit can be retained at the assembly, but accelerated wear of coupling components occurs that may accelerate wear of or cause damage to other components

Engineering Contradiction:

Improvedrill bit retentionVSAvoidservice life of coupling components

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The retaining sleeve is extracted as a separate, dedicated retention component from the drive sub assembly. By isolating the retention function into a separate sleeve component, the wear and stress are concentrated on this removable part rather than being distributed to the drive sub and other critical components. This protects the main assembly from accelerated wear and potential damage.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The retaining sleeve is designed as a sacrificial component with a shorter service life than the drive sub. It is easier and more economical to replace the worn sleeve than to repair or replace the entire drive sub assembly. The sleeve absorbs the wear from retention and detachment operations, protecting more valuable components from damage.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Data Source

PatentEP2896778B1Quick release down-the-hole hammer drill bit assembly

Publication Date: 2019.01.02 SANDVIK INTELLECTUAL PROPERTY AB

Figure 1
Figure 2~3
Figure 4~5

AI summary

A quick release down-the-hole (DTH) hammer drill bit assembly (100) in which a drill bit (105) is releaseably retained at a drive transmission component (drive sub) (110) via a retaining sleeve (123) and respective retaining formations (200, 201, 202, 203) to axially couple and lock the drill bit at the assembly. In particular, the drill bit is retained exclusively at the assembly via retaining formations at the drive sub, the sleeve and the drill bit without a requirement for additional retaining rings that would otherwise axially lock the drill bit at the drive sub.